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Update docs
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Rhys Weatherley
@@ -120,430 +120,538 @@ var searchBox = new SearchBox("searchBox", "search",false,'Search');
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<div class="line"><a name="l00030"></a><span class="lineno"> 30</span> <span class="preprocessor"></span><span class="comment">// The Arduino Due does not have any EEPROM natively on the main chip.</span></div>
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<div class="line"><a name="l00031"></a><span class="lineno"> 31</span> <span class="comment">// However, it does have a TRNG and flash memory.</span></div>
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<div class="line"><a name="l00032"></a><span class="lineno"> 32</span> <span class="preprocessor">#define RNG_DUE_TRNG 1</span></div>
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<div class="line"><a name="l00033"></a><span class="lineno"> 33</span> <span class="preprocessor"></span><span class="preprocessor">#else</span></div>
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<div class="line"><a name="l00034"></a><span class="lineno"> 34</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_EEPROM 1</span></div>
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<div class="line"><a name="l00035"></a><span class="lineno"> 35</span> <span class="preprocessor"></span><span class="preprocessor">#include <avr/eeprom.h></span></div>
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<div class="line"><a name="l00036"></a><span class="lineno"> 36</span> <span class="preprocessor">#endif</span></div>
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<div class="line"><a name="l00037"></a><span class="lineno"> 37</span> <span class="preprocessor"></span><span class="preprocessor">#include <string.h></span></div>
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<div class="line"><a name="l00038"></a><span class="lineno"> 38</span> </div>
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<div class="line"><a name="l00132"></a><span class="lineno"> 132</span> <a class="code" href="classRNGClass.html">RNGClass</a> RNG;</div>
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<div class="line"><a name="l00133"></a><span class="lineno"> 133</span> </div>
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<div class="line"><a name="l00139"></a><span class="lineno"> 139</span> <span class="comment">// Number of ChaCha hash rounds to use for random number generation.</span></div>
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<div class="line"><a name="l00140"></a><span class="lineno"> 140</span> <span class="preprocessor">#define RNG_ROUNDS 20</span></div>
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<div class="line"><a name="l00141"></a><span class="lineno"> 141</span> <span class="preprocessor"></span></div>
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<div class="line"><a name="l00142"></a><span class="lineno"> 142</span> <span class="comment">// Force a rekey after this many blocks of random data.</span></div>
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<div class="line"><a name="l00143"></a><span class="lineno"> 143</span> <span class="preprocessor">#define RNG_REKEY_BLOCKS 16</span></div>
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<div class="line"><a name="l00144"></a><span class="lineno"> 144</span> <span class="preprocessor"></span></div>
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<div class="line"><a name="l00145"></a><span class="lineno"> 145</span> <span class="comment">// Maximum entropy credit that can be contained in the pool.</span></div>
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<div class="line"><a name="l00146"></a><span class="lineno"> 146</span> <span class="preprocessor">#define RNG_MAX_CREDITS 384</span></div>
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<div class="line"><a name="l00147"></a><span class="lineno"> 147</span> <span class="preprocessor"></span></div>
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<div class="line"><a name="l00150"></a><span class="lineno"> 150</span> <span class="comment">// Tag for 256-bit ChaCha20 keys. This will always appear in the</span></div>
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<div class="line"><a name="l00151"></a><span class="lineno"> 151</span> <span class="comment">// first 16 bytes of the block. The remaining 48 bytes are the seed.</span></div>
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<div class="line"><a name="l00152"></a><span class="lineno"> 152</span> <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">char</span> tagRNG[16] PROGMEM = {</div>
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<div class="line"><a name="l00153"></a><span class="lineno"> 153</span>  <span class="charliteral">'e'</span>, <span class="charliteral">'x'</span>, <span class="charliteral">'p'</span>, <span class="charliteral">'a'</span>, <span class="charliteral">'n'</span>, <span class="charliteral">'d'</span>, <span class="charliteral">' '</span>, <span class="charliteral">'3'</span>,</div>
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<div class="line"><a name="l00154"></a><span class="lineno"> 154</span>  <span class="charliteral">'2'</span>, <span class="charliteral">'-'</span>, <span class="charliteral">'b'</span>, <span class="charliteral">'y'</span>, <span class="charliteral">'t'</span>, <span class="charliteral">'e'</span>, <span class="charliteral">' '</span>, <span class="charliteral">'k'</span></div>
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<div class="line"><a name="l00155"></a><span class="lineno"> 155</span> };</div>
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<div class="line"><a name="l00156"></a><span class="lineno"> 156</span> </div>
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<div class="line"><a name="l00157"></a><span class="lineno"> 157</span> <span class="comment">// Initialization seed. This is the ChaCha20 output of hashing</span></div>
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<div class="line"><a name="l00158"></a><span class="lineno"> 158</span> <span class="comment">// "expand 32-byte k" followed by 48 bytes set to the numbers 1 to 48.</span></div>
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<div class="line"><a name="l00159"></a><span class="lineno"> 159</span> <span class="comment">// The ChaCha20 output block is then truncated to the first 48 bytes.</span></div>
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<div class="line"><a name="l00160"></a><span class="lineno"> 160</span> <span class="comment">//</span></div>
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<div class="line"><a name="l00161"></a><span class="lineno"> 161</span> <span class="comment">// This value is intended to start the RNG in a semi-chaotic state if</span></div>
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<div class="line"><a name="l00162"></a><span class="lineno"> 162</span> <span class="comment">// we don't have a previously saved seed in EEPROM.</span></div>
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<div class="line"><a name="l00163"></a><span class="lineno"> 163</span> <span class="keyword">static</span> <span class="keyword">const</span> uint8_t initRNG[48] PROGMEM = {</div>
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<div class="line"><a name="l00164"></a><span class="lineno"> 164</span>  0xB0, 0x2A, 0xAE, 0x7D, 0xEE, 0xCB, 0xBB, 0xB1,</div>
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<div class="line"><a name="l00165"></a><span class="lineno"> 165</span>  0xFC, 0x03, 0x6F, 0xDD, 0xDC, 0x7D, 0x76, 0x67,</div>
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<div class="line"><a name="l00166"></a><span class="lineno"> 166</span>  0x0C, 0xE8, 0x1F, 0x0D, 0xA3, 0xA0, 0xAA, 0x1E,</div>
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<div class="line"><a name="l00167"></a><span class="lineno"> 167</span>  0xB0, 0xBD, 0x72, 0x6B, 0x2B, 0x4C, 0x8A, 0x7E,</div>
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<div class="line"><a name="l00168"></a><span class="lineno"> 168</span>  0x34, 0xFC, 0x37, 0x60, 0xF4, 0x1E, 0x22, 0xA0,</div>
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<div class="line"><a name="l00169"></a><span class="lineno"> 169</span>  0x0B, 0xFB, 0x18, 0x84, 0x60, 0xA5, 0x77, 0x72</div>
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<div class="line"><a name="l00170"></a><span class="lineno"> 170</span> };</div>
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<div class="line"><a name="l00171"></a><span class="lineno"> 171</span> </div>
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<div class="line"><a name="l00182"></a><span class="lineno"><a class="line" href="classRNGClass.html#acbcf327242f51ae2d9209aeaa45e30e9"> 182</a></span> <a class="code" href="classRNGClass.html#acbcf327242f51ae2d9209aeaa45e30e9">RNGClass::RNGClass</a>()</div>
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<div class="line"><a name="l00183"></a><span class="lineno"> 183</span>  : address(0)</div>
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<div class="line"><a name="l00184"></a><span class="lineno"> 184</span>  , credits(0)</div>
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<div class="line"><a name="l00185"></a><span class="lineno"> 185</span>  , firstSave(1)</div>
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<div class="line"><a name="l00186"></a><span class="lineno"> 186</span>  , timer(0)</div>
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<div class="line"><a name="l00187"></a><span class="lineno"> 187</span>  , timeout(3600000UL) <span class="comment">// 1 hour in milliseconds</span></div>
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<div class="line"><a name="l00188"></a><span class="lineno"> 188</span>  , count(0)</div>
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<div class="line"><a name="l00189"></a><span class="lineno"> 189</span>  , trngPosn(0)</div>
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<div class="line"><a name="l00190"></a><span class="lineno"> 190</span> {</div>
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<div class="line"><a name="l00191"></a><span class="lineno"> 191</span> }</div>
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<div class="line"><a name="l00192"></a><span class="lineno"> 192</span> </div>
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<div class="line"><a name="l00196"></a><span class="lineno"><a class="line" href="classRNGClass.html#aef3ee2fb14a39caf650dc90a0226dd31"> 196</a></span> <a class="code" href="classRNGClass.html#aef3ee2fb14a39caf650dc90a0226dd31">RNGClass::~RNGClass</a>()</div>
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<div class="line"><a name="l00197"></a><span class="lineno"> 197</span> {</div>
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<div class="line"><a name="l00198"></a><span class="lineno"> 198</span> <span class="preprocessor">#if defined(RNG_DUE_TRNG)</span></div>
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<div class="line"><a name="l00199"></a><span class="lineno"> 199</span> <span class="preprocessor"></span> <span class="comment">// Disable the TRNG in the Arduino Due.</span></div>
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<div class="line"><a name="l00200"></a><span class="lineno"> 200</span>  REG_TRNG_CR = TRNG_CR_KEY(0x524E47);</div>
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<div class="line"><a name="l00201"></a><span class="lineno"> 201</span> <span class="preprocessor">#endif</span></div>
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<div class="line"><a name="l00202"></a><span class="lineno"> 202</span> <span class="preprocessor"></span> clean(block);</div>
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<div class="line"><a name="l00203"></a><span class="lineno"> 203</span>  clean(stream);</div>
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<div class="line"><a name="l00204"></a><span class="lineno"> 204</span> }</div>
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<div class="line"><a name="l00205"></a><span class="lineno"> 205</span> </div>
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<div class="line"><a name="l00206"></a><span class="lineno"> 206</span> <span class="preprocessor">#if defined(RNG_DUE_TRNG)</span></div>
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<div class="line"><a name="l00207"></a><span class="lineno"> 207</span> <span class="preprocessor"></span></div>
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<div class="line"><a name="l00208"></a><span class="lineno"> 208</span> <span class="comment">// Find the flash memory of interest. Allow for the possibility</span></div>
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<div class="line"><a name="l00209"></a><span class="lineno"> 209</span> <span class="comment">// of other SAM-based Arduino variants in the future.</span></div>
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<div class="line"><a name="l00210"></a><span class="lineno"> 210</span> <span class="preprocessor">#if defined(IFLASH1_ADDR)</span></div>
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<div class="line"><a name="l00211"></a><span class="lineno"> 211</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_FLASH_ADDR IFLASH1_ADDR</span></div>
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<div class="line"><a name="l00212"></a><span class="lineno"> 212</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_FLASH_SIZE IFLASH1_SIZE</span></div>
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<div class="line"><a name="l00213"></a><span class="lineno"> 213</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_FLASH_PAGE_SIZE IFLASH1_PAGE_SIZE</span></div>
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<div class="line"><a name="l00214"></a><span class="lineno"> 214</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_EFC EFC1</span></div>
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<div class="line"><a name="l00215"></a><span class="lineno"> 215</span> <span class="preprocessor"></span><span class="preprocessor">#elif defined(IFLASH0_ADDR)</span></div>
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<div class="line"><a name="l00216"></a><span class="lineno"> 216</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_FLASH_ADDR IFLASH0_ADDR</span></div>
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<div class="line"><a name="l00217"></a><span class="lineno"> 217</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_FLASH_SIZE IFLASH0_SIZE</span></div>
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<div class="line"><a name="l00218"></a><span class="lineno"> 218</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_FLASH_PAGE_SIZE IFLASH0_PAGE_SIZE</span></div>
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<div class="line"><a name="l00219"></a><span class="lineno"> 219</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_EFC EFC0</span></div>
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<div class="line"><a name="l00220"></a><span class="lineno"> 220</span> <span class="preprocessor"></span><span class="preprocessor">#else</span></div>
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<div class="line"><a name="l00221"></a><span class="lineno"> 221</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_FLASH_ADDR IFLASH_ADDR</span></div>
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<div class="line"><a name="l00222"></a><span class="lineno"> 222</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_FLASH_SIZE IFLASH_SIZE</span></div>
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<div class="line"><a name="l00223"></a><span class="lineno"> 223</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_FLASH_PAGE_SIZE IFLASH_PAGE_SIZE</span></div>
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<div class="line"><a name="l00224"></a><span class="lineno"> 224</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_EFC EFC</span></div>
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<div class="line"><a name="l00225"></a><span class="lineno"> 225</span> <span class="preprocessor"></span><span class="preprocessor">#endif</span></div>
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<div class="line"><a name="l00226"></a><span class="lineno"> 226</span> <span class="preprocessor"></span></div>
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<div class="line"><a name="l00227"></a><span class="lineno"> 227</span> <span class="comment">// Address of the flash page to use for saving the seed on the Due.</span></div>
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<div class="line"><a name="l00228"></a><span class="lineno"> 228</span> <span class="comment">// All SAM variants have a page size of 256 bytes or greater so there is</span></div>
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<div class="line"><a name="l00229"></a><span class="lineno"> 229</span> <span class="comment">// plenty of room for the 48 byte seed in the last page of flash memory.</span></div>
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<div class="line"><a name="l00230"></a><span class="lineno"> 230</span> <span class="preprocessor">#define RNG_SEED_ADDR (RNG_FLASH_ADDR + RNG_FLASH_SIZE - RNG_FLASH_PAGE_SIZE)</span></div>
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<div class="line"><a name="l00231"></a><span class="lineno"> 231</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_SEED_PAGE ((RNG_FLASH_SIZE / RNG_FLASH_PAGE_SIZE) - 1)</span></div>
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<div class="line"><a name="l00232"></a><span class="lineno"> 232</span> <span class="preprocessor"></span></div>
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<div class="line"><a name="l00233"></a><span class="lineno"> 233</span> <span class="comment">// Stir in the unique identifier for the Arduino Due's CPU.</span></div>
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<div class="line"><a name="l00234"></a><span class="lineno"> 234</span> <span class="comment">// This function must be in RAM because programs running out of</span></div>
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<div class="line"><a name="l00235"></a><span class="lineno"> 235</span> <span class="comment">// flash memory are not allowed to access the unique identifier.</span></div>
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<div class="line"><a name="l00236"></a><span class="lineno"> 236</span> <span class="comment">// Info from: http://forum.arduino.cc/index.php?topic=289190.0</span></div>
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<div class="line"><a name="l00237"></a><span class="lineno"> 237</span> __attribute__((section(<span class="stringliteral">".ramfunc"</span>)))</div>
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<div class="line"><a name="l00238"></a><span class="lineno"> 238</span> static <span class="keywordtype">void</span> stirUniqueIdentifier(<span class="keywordtype">void</span>)</div>
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<div class="line"><a name="l00239"></a><span class="lineno"> 239</span> {</div>
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<div class="line"><a name="l00240"></a><span class="lineno"> 240</span>  uint32_t <span class="keywordtype">id</span>[4];</div>
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<div class="line"><a name="l00241"></a><span class="lineno"> 241</span> </div>
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<div class="line"><a name="l00242"></a><span class="lineno"> 242</span>  <span class="comment">// Start Read Unique Identifier.</span></div>
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<div class="line"><a name="l00243"></a><span class="lineno"> 243</span>  RNG_EFC->EEFC_FCR = (0x5A << 24) | EFC_FCMD_STUI;</div>
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<div class="line"><a name="l00244"></a><span class="lineno"> 244</span>  <span class="keywordflow">while</span> ((RNG_EFC->EEFC_FSR & EEFC_FSR_FRDY) != 0)</div>
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<div class="line"><a name="l00245"></a><span class="lineno"> 245</span>  ; <span class="comment">// do nothing until FRDY falls.</span></div>
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<div class="line"><a name="l00246"></a><span class="lineno"> 246</span> </div>
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<div class="line"><a name="l00247"></a><span class="lineno"> 247</span>  <span class="comment">// Read the identifier.</span></div>
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<div class="line"><a name="l00248"></a><span class="lineno"> 248</span>  <span class="keywordtype">id</span>[0] = *((<span class="keyword">const</span> uint32_t *)RNG_FLASH_ADDR);</div>
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<div class="line"><a name="l00249"></a><span class="lineno"> 249</span>  <span class="keywordtype">id</span>[1] = *((<span class="keyword">const</span> uint32_t *)(RNG_FLASH_ADDR + 4));</div>
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<div class="line"><a name="l00250"></a><span class="lineno"> 250</span>  <span class="keywordtype">id</span>[2] = *((<span class="keyword">const</span> uint32_t *)(RNG_FLASH_ADDR + 8));</div>
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<div class="line"><a name="l00251"></a><span class="lineno"> 251</span>  <span class="keywordtype">id</span>[3] = *((<span class="keyword">const</span> uint32_t *)(RNG_FLASH_ADDR + 12));</div>
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<div class="line"><a name="l00252"></a><span class="lineno"> 252</span> </div>
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<div class="line"><a name="l00253"></a><span class="lineno"> 253</span>  <span class="comment">// Stop Read Unique Identifier.</span></div>
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<div class="line"><a name="l00254"></a><span class="lineno"> 254</span>  RNG_EFC->EEFC_FCR = (0x5A << 24) | EFC_FCMD_SPUI;</div>
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<div class="line"><a name="l00255"></a><span class="lineno"> 255</span>  <span class="keywordflow">while</span> ((RNG_EFC->EEFC_FSR & EEFC_FSR_FRDY) == 0)</div>
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<div class="line"><a name="l00256"></a><span class="lineno"> 256</span>  ; <span class="comment">// do nothing until FRDY rises.</span></div>
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<div class="line"><a name="l00033"></a><span class="lineno"> 33</span> <span class="preprocessor"></span><span class="preprocessor">#elif defined(__AVR__)</span></div>
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<div class="line"><a name="l00034"></a><span class="lineno"> 34</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_EEPROM 1 // Use EEPROM to save the seed.</span></div>
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<div class="line"><a name="l00035"></a><span class="lineno"> 35</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_WATCHDOG 1 // Harvest entropy from watchdog jitter.</span></div>
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<div class="line"><a name="l00036"></a><span class="lineno"> 36</span> <span class="preprocessor"></span><span class="preprocessor">#include <avr/eeprom.h></span></div>
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<div class="line"><a name="l00037"></a><span class="lineno"> 37</span> <span class="preprocessor">#include <avr/wdt.h></span></div>
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<div class="line"><a name="l00038"></a><span class="lineno"> 38</span> <span class="preprocessor">#endif</span></div>
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<div class="line"><a name="l00039"></a><span class="lineno"> 39</span> <span class="preprocessor"></span><span class="preprocessor">#include <string.h></span></div>
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<div class="line"><a name="l00040"></a><span class="lineno"> 40</span> </div>
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<div class="line"><a name="l00134"></a><span class="lineno"> 134</span> <a class="code" href="classRNGClass.html">RNGClass</a> RNG;</div>
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<div class="line"><a name="l00135"></a><span class="lineno"> 135</span> </div>
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<div class="line"><a name="l00141"></a><span class="lineno"> 141</span> <span class="comment">// Number of ChaCha hash rounds to use for random number generation.</span></div>
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<div class="line"><a name="l00142"></a><span class="lineno"> 142</span> <span class="preprocessor">#define RNG_ROUNDS 20</span></div>
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<div class="line"><a name="l00143"></a><span class="lineno"> 143</span> <span class="preprocessor"></span></div>
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<div class="line"><a name="l00144"></a><span class="lineno"> 144</span> <span class="comment">// Force a rekey after this many blocks of random data.</span></div>
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<div class="line"><a name="l00145"></a><span class="lineno"> 145</span> <span class="preprocessor">#define RNG_REKEY_BLOCKS 16</span></div>
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<div class="line"><a name="l00146"></a><span class="lineno"> 146</span> <span class="preprocessor"></span></div>
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<div class="line"><a name="l00147"></a><span class="lineno"> 147</span> <span class="comment">// Maximum entropy credit that can be contained in the pool.</span></div>
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<div class="line"><a name="l00148"></a><span class="lineno"> 148</span> <span class="preprocessor">#define RNG_MAX_CREDITS 384</span></div>
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<div class="line"><a name="l00149"></a><span class="lineno"> 149</span> <span class="preprocessor"></span></div>
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<div class="line"><a name="l00152"></a><span class="lineno"> 152</span> <span class="comment">// Tag for 256-bit ChaCha20 keys. This will always appear in the</span></div>
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<div class="line"><a name="l00153"></a><span class="lineno"> 153</span> <span class="comment">// first 16 bytes of the block. The remaining 48 bytes are the seed.</span></div>
|
||||
<div class="line"><a name="l00154"></a><span class="lineno"> 154</span> <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">char</span> tagRNG[16] PROGMEM = {</div>
|
||||
<div class="line"><a name="l00155"></a><span class="lineno"> 155</span>  <span class="charliteral">'e'</span>, <span class="charliteral">'x'</span>, <span class="charliteral">'p'</span>, <span class="charliteral">'a'</span>, <span class="charliteral">'n'</span>, <span class="charliteral">'d'</span>, <span class="charliteral">' '</span>, <span class="charliteral">'3'</span>,</div>
|
||||
<div class="line"><a name="l00156"></a><span class="lineno"> 156</span>  <span class="charliteral">'2'</span>, <span class="charliteral">'-'</span>, <span class="charliteral">'b'</span>, <span class="charliteral">'y'</span>, <span class="charliteral">'t'</span>, <span class="charliteral">'e'</span>, <span class="charliteral">' '</span>, <span class="charliteral">'k'</span></div>
|
||||
<div class="line"><a name="l00157"></a><span class="lineno"> 157</span> };</div>
|
||||
<div class="line"><a name="l00158"></a><span class="lineno"> 158</span> </div>
|
||||
<div class="line"><a name="l00159"></a><span class="lineno"> 159</span> <span class="comment">// Initialization seed. This is the ChaCha20 output of hashing</span></div>
|
||||
<div class="line"><a name="l00160"></a><span class="lineno"> 160</span> <span class="comment">// "expand 32-byte k" followed by 48 bytes set to the numbers 1 to 48.</span></div>
|
||||
<div class="line"><a name="l00161"></a><span class="lineno"> 161</span> <span class="comment">// The ChaCha20 output block is then truncated to the first 48 bytes.</span></div>
|
||||
<div class="line"><a name="l00162"></a><span class="lineno"> 162</span> <span class="comment">//</span></div>
|
||||
<div class="line"><a name="l00163"></a><span class="lineno"> 163</span> <span class="comment">// This value is intended to start the RNG in a semi-chaotic state if</span></div>
|
||||
<div class="line"><a name="l00164"></a><span class="lineno"> 164</span> <span class="comment">// we don't have a previously saved seed in EEPROM.</span></div>
|
||||
<div class="line"><a name="l00165"></a><span class="lineno"> 165</span> <span class="keyword">static</span> <span class="keyword">const</span> uint8_t initRNG[48] PROGMEM = {</div>
|
||||
<div class="line"><a name="l00166"></a><span class="lineno"> 166</span>  0xB0, 0x2A, 0xAE, 0x7D, 0xEE, 0xCB, 0xBB, 0xB1,</div>
|
||||
<div class="line"><a name="l00167"></a><span class="lineno"> 167</span>  0xFC, 0x03, 0x6F, 0xDD, 0xDC, 0x7D, 0x76, 0x67,</div>
|
||||
<div class="line"><a name="l00168"></a><span class="lineno"> 168</span>  0x0C, 0xE8, 0x1F, 0x0D, 0xA3, 0xA0, 0xAA, 0x1E,</div>
|
||||
<div class="line"><a name="l00169"></a><span class="lineno"> 169</span>  0xB0, 0xBD, 0x72, 0x6B, 0x2B, 0x4C, 0x8A, 0x7E,</div>
|
||||
<div class="line"><a name="l00170"></a><span class="lineno"> 170</span>  0x34, 0xFC, 0x37, 0x60, 0xF4, 0x1E, 0x22, 0xA0,</div>
|
||||
<div class="line"><a name="l00171"></a><span class="lineno"> 171</span>  0x0B, 0xFB, 0x18, 0x84, 0x60, 0xA5, 0x77, 0x72</div>
|
||||
<div class="line"><a name="l00172"></a><span class="lineno"> 172</span> };</div>
|
||||
<div class="line"><a name="l00173"></a><span class="lineno"> 173</span> </div>
|
||||
<div class="line"><a name="l00174"></a><span class="lineno"> 174</span> <span class="preprocessor">#if defined(RNG_WATCHDOG)</span></div>
|
||||
<div class="line"><a name="l00175"></a><span class="lineno"> 175</span> <span class="preprocessor"></span></div>
|
||||
<div class="line"><a name="l00176"></a><span class="lineno"> 176</span> <span class="comment">// Use jitter between the watchdog timer and the main CPU clock to</span></div>
|
||||
<div class="line"><a name="l00177"></a><span class="lineno"> 177</span> <span class="comment">// harvest some entropy on AVR-based systems. This technique comes from:</span></div>
|
||||
<div class="line"><a name="l00178"></a><span class="lineno"> 178</span> <span class="comment">//</span></div>
|
||||
<div class="line"><a name="l00179"></a><span class="lineno"> 179</span> <span class="comment">// https://sites.google.com/site/astudyofentropy/project-definition/timer-jitter-entropy-sources/entropy-library</span></div>
|
||||
<div class="line"><a name="l00180"></a><span class="lineno"> 180</span> <span class="comment">//</span></div>
|
||||
<div class="line"><a name="l00181"></a><span class="lineno"> 181</span> <span class="comment">// The watchdog generates entropy very slowly - it can take around 32 seconds</span></div>
|
||||
<div class="line"><a name="l00182"></a><span class="lineno"> 182</span> <span class="comment">// to generate 256 bits of entropy credit. This is a "better than nothing"</span></div>
|
||||
<div class="line"><a name="l00183"></a><span class="lineno"> 183</span> <span class="comment">// entropy source but a real noise source is definitely recommended.</span></div>
|
||||
<div class="line"><a name="l00184"></a><span class="lineno"> 184</span> </div>
|
||||
<div class="line"><a name="l00185"></a><span class="lineno"> 185</span> <span class="comment">// Helper macros for specific 32-bit shift counts.</span></div>
|
||||
<div class="line"><a name="l00186"></a><span class="lineno"> 186</span> <span class="preprocessor">#define leftShift3(value) ((value) << 3)</span></div>
|
||||
<div class="line"><a name="l00187"></a><span class="lineno"> 187</span> <span class="preprocessor"></span><span class="preprocessor">#define leftShift10(value) ((value) << 10)</span></div>
|
||||
<div class="line"><a name="l00188"></a><span class="lineno"> 188</span> <span class="preprocessor"></span><span class="preprocessor">#define leftShift15(value) ((value) << 15)</span></div>
|
||||
<div class="line"><a name="l00189"></a><span class="lineno"> 189</span> <span class="preprocessor"></span><span class="preprocessor">#define rightShift6(value) ((value) >> 6)</span></div>
|
||||
<div class="line"><a name="l00190"></a><span class="lineno"> 190</span> <span class="preprocessor"></span><span class="preprocessor">#define rightShift11(value) ((value) >> 11)</span></div>
|
||||
<div class="line"><a name="l00191"></a><span class="lineno"> 191</span> <span class="preprocessor"></span></div>
|
||||
<div class="line"><a name="l00192"></a><span class="lineno"> 192</span> <span class="keyword">static</span> uint32_t <span class="keyword">volatile</span> hash = 0;</div>
|
||||
<div class="line"><a name="l00193"></a><span class="lineno"> 193</span> <span class="keyword">static</span> uint8_t <span class="keyword">volatile</span> outBits = 0;</div>
|
||||
<div class="line"><a name="l00194"></a><span class="lineno"> 194</span> </div>
|
||||
<div class="line"><a name="l00195"></a><span class="lineno"> 195</span> <span class="comment">// Watchdog interrupt handler. This fires off every 16ms. We collect</span></div>
|
||||
<div class="line"><a name="l00196"></a><span class="lineno"> 196</span> <span class="comment">// 32 bits and then pass them off onto RNGClass::loop().</span></div>
|
||||
<div class="line"><a name="l00197"></a><span class="lineno"> 197</span> ISR(WDT_vect)</div>
|
||||
<div class="line"><a name="l00198"></a><span class="lineno"> 198</span> {</div>
|
||||
<div class="line"><a name="l00199"></a><span class="lineno"> 199</span>  <span class="comment">// Read the low byte of Timer 1. We assume that the timer was</span></div>
|
||||
<div class="line"><a name="l00200"></a><span class="lineno"> 200</span>  <span class="comment">// initialized by the Arduino startup code for PWM use or that the</span></div>
|
||||
<div class="line"><a name="l00201"></a><span class="lineno"> 201</span>  <span class="comment">// application is free-running Timer 1 for its own purposes.</span></div>
|
||||
<div class="line"><a name="l00202"></a><span class="lineno"> 202</span>  <span class="comment">// Timer 0 is used on systems that don't have a Timer 1.</span></div>
|
||||
<div class="line"><a name="l00203"></a><span class="lineno"> 203</span> <span class="preprocessor">#if defined(TCNT1L)</span></div>
|
||||
<div class="line"><a name="l00204"></a><span class="lineno"> 204</span> <span class="preprocessor"></span> <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> value = TCNT1L;</div>
|
||||
<div class="line"><a name="l00205"></a><span class="lineno"> 205</span> <span class="preprocessor">#elif defined(TCNT0L)</span></div>
|
||||
<div class="line"><a name="l00206"></a><span class="lineno"> 206</span> <span class="preprocessor"></span> <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> value = TCNT0L;</div>
|
||||
<div class="line"><a name="l00207"></a><span class="lineno"> 207</span> <span class="preprocessor">#else</span></div>
|
||||
<div class="line"><a name="l00208"></a><span class="lineno"> 208</span> <span class="preprocessor"></span> <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> value = TCNT0;</div>
|
||||
<div class="line"><a name="l00209"></a><span class="lineno"> 209</span> <span class="preprocessor">#endif</span></div>
|
||||
<div class="line"><a name="l00210"></a><span class="lineno"> 210</span> <span class="preprocessor"></span> <span class="comment">// Use Jenkin's one-at-a-time hash function to scatter the entropy a bit.</span></div>
|
||||
<div class="line"><a name="l00211"></a><span class="lineno"> 211</span>  <span class="comment">// https://en.wikipedia.org/wiki/Jenkins_hash_function</span></div>
|
||||
<div class="line"><a name="l00212"></a><span class="lineno"> 212</span>  hash += value;</div>
|
||||
<div class="line"><a name="l00213"></a><span class="lineno"> 213</span>  hash += leftShift10(hash);</div>
|
||||
<div class="line"><a name="l00214"></a><span class="lineno"> 214</span>  hash ^= rightShift6(hash);</div>
|
||||
<div class="line"><a name="l00215"></a><span class="lineno"> 215</span>  ++outBits;</div>
|
||||
<div class="line"><a name="l00216"></a><span class="lineno"> 216</span> }</div>
|
||||
<div class="line"><a name="l00217"></a><span class="lineno"> 217</span> </div>
|
||||
<div class="line"><a name="l00218"></a><span class="lineno"> 218</span> <span class="preprocessor">#endif // RNG_WATCHDOG</span></div>
|
||||
<div class="line"><a name="l00219"></a><span class="lineno"> 219</span> <span class="preprocessor"></span></div>
|
||||
<div class="line"><a name="l00230"></a><span class="lineno"><a class="line" href="classRNGClass.html#acbcf327242f51ae2d9209aeaa45e30e9"> 230</a></span> <a class="code" href="classRNGClass.html#acbcf327242f51ae2d9209aeaa45e30e9">RNGClass::RNGClass</a>()</div>
|
||||
<div class="line"><a name="l00231"></a><span class="lineno"> 231</span>  : address(0)</div>
|
||||
<div class="line"><a name="l00232"></a><span class="lineno"> 232</span>  , credits(0)</div>
|
||||
<div class="line"><a name="l00233"></a><span class="lineno"> 233</span>  , firstSave(1)</div>
|
||||
<div class="line"><a name="l00234"></a><span class="lineno"> 234</span>  , timer(0)</div>
|
||||
<div class="line"><a name="l00235"></a><span class="lineno"> 235</span>  , timeout(3600000UL) <span class="comment">// 1 hour in milliseconds</span></div>
|
||||
<div class="line"><a name="l00236"></a><span class="lineno"> 236</span>  , count(0)</div>
|
||||
<div class="line"><a name="l00237"></a><span class="lineno"> 237</span>  , trngPosn(0)</div>
|
||||
<div class="line"><a name="l00238"></a><span class="lineno"> 238</span> {</div>
|
||||
<div class="line"><a name="l00239"></a><span class="lineno"> 239</span> }</div>
|
||||
<div class="line"><a name="l00240"></a><span class="lineno"> 240</span> </div>
|
||||
<div class="line"><a name="l00244"></a><span class="lineno"><a class="line" href="classRNGClass.html#aef3ee2fb14a39caf650dc90a0226dd31"> 244</a></span> <a class="code" href="classRNGClass.html#aef3ee2fb14a39caf650dc90a0226dd31">RNGClass::~RNGClass</a>()</div>
|
||||
<div class="line"><a name="l00245"></a><span class="lineno"> 245</span> {</div>
|
||||
<div class="line"><a name="l00246"></a><span class="lineno"> 246</span> <span class="preprocessor">#if defined(RNG_DUE_TRNG)</span></div>
|
||||
<div class="line"><a name="l00247"></a><span class="lineno"> 247</span> <span class="preprocessor"></span> <span class="comment">// Disable the TRNG in the Arduino Due.</span></div>
|
||||
<div class="line"><a name="l00248"></a><span class="lineno"> 248</span>  REG_TRNG_CR = TRNG_CR_KEY(0x524E47);</div>
|
||||
<div class="line"><a name="l00249"></a><span class="lineno"> 249</span> <span class="preprocessor">#endif</span></div>
|
||||
<div class="line"><a name="l00250"></a><span class="lineno"> 250</span> <span class="preprocessor"></span><span class="preprocessor">#if defined(RNG_WATCHDOG)</span></div>
|
||||
<div class="line"><a name="l00251"></a><span class="lineno"> 251</span> <span class="preprocessor"></span> <span class="comment">// Disable interrupts and reset the watchdog.</span></div>
|
||||
<div class="line"><a name="l00252"></a><span class="lineno"> 252</span>  cli();</div>
|
||||
<div class="line"><a name="l00253"></a><span class="lineno"> 253</span>  wdt_reset();</div>
|
||||
<div class="line"><a name="l00254"></a><span class="lineno"> 254</span> </div>
|
||||
<div class="line"><a name="l00255"></a><span class="lineno"> 255</span>  <span class="comment">// Clear the "reset due to watchdog" flag.</span></div>
|
||||
<div class="line"><a name="l00256"></a><span class="lineno"> 256</span>  MCUSR &= ~(1 << WDRF);</div>
|
||||
<div class="line"><a name="l00257"></a><span class="lineno"> 257</span> </div>
|
||||
<div class="line"><a name="l00258"></a><span class="lineno"> 258</span>  <span class="comment">// Stir the unique identifier into the entropy pool.</span></div>
|
||||
<div class="line"><a name="l00259"></a><span class="lineno"> 259</span>  RNG.<a class="code" href="classRNGClass.html#ad99535ea23ae2fec55bdebb8c24def02">stir</a>((uint8_t *)<span class="keywordtype">id</span>, <span class="keyword">sizeof</span>(<span class="keywordtype">id</span>));</div>
|
||||
<div class="line"><a name="l00260"></a><span class="lineno"> 260</span> }</div>
|
||||
<div class="line"><a name="l00258"></a><span class="lineno"> 258</span>  <span class="comment">// Disable the watchdog.</span></div>
|
||||
<div class="line"><a name="l00259"></a><span class="lineno"> 259</span>  _WD_CONTROL_REG |= (1 << _WD_CHANGE_BIT) | (1 << WDE);</div>
|
||||
<div class="line"><a name="l00260"></a><span class="lineno"> 260</span>  _WD_CONTROL_REG = 0;</div>
|
||||
<div class="line"><a name="l00261"></a><span class="lineno"> 261</span> </div>
|
||||
<div class="line"><a name="l00262"></a><span class="lineno"> 262</span> <span class="comment">// Erases the flash page containing the seed and then writes the new seed.</span></div>
|
||||
<div class="line"><a name="l00263"></a><span class="lineno"> 263</span> <span class="comment">// It is assumed the seed has already been loaded into the latch registers.</span></div>
|
||||
<div class="line"><a name="l00264"></a><span class="lineno"> 264</span> __attribute__((section(<span class="stringliteral">".ramfunc"</span>)))</div>
|
||||
<div class="line"><a name="l00265"></a><span class="lineno"> 265</span> static <span class="keywordtype">void</span> eraseAndWriteSeed()</div>
|
||||
<div class="line"><a name="l00266"></a><span class="lineno"> 266</span> {</div>
|
||||
<div class="line"><a name="l00267"></a><span class="lineno"> 267</span>  <span class="comment">// Execute the "Erase and Write Page" command.</span></div>
|
||||
<div class="line"><a name="l00268"></a><span class="lineno"> 268</span>  RNG_EFC->EEFC_FCR = (0x5A << 24) | (RNG_SEED_PAGE << 8) | EFC_FCMD_EWP;</div>
|
||||
<div class="line"><a name="l00269"></a><span class="lineno"> 269</span> </div>
|
||||
<div class="line"><a name="l00270"></a><span class="lineno"> 270</span>  <span class="comment">// Wait for the FRDY bit to be raised.</span></div>
|
||||
<div class="line"><a name="l00271"></a><span class="lineno"> 271</span>  <span class="keywordflow">while</span> ((RNG_EFC->EEFC_FSR & EEFC_FSR_FRDY) == 0)</div>
|
||||
<div class="line"><a name="l00272"></a><span class="lineno"> 272</span>  ; <span class="comment">// do nothing until FRDY rises.</span></div>
|
||||
<div class="line"><a name="l00273"></a><span class="lineno"> 273</span> }</div>
|
||||
<div class="line"><a name="l00274"></a><span class="lineno"> 274</span> </div>
|
||||
<div class="line"><a name="l00275"></a><span class="lineno"> 275</span> <span class="preprocessor">#endif</span></div>
|
||||
<div class="line"><a name="l00276"></a><span class="lineno"> 276</span> <span class="preprocessor"></span></div>
|
||||
<div class="line"><a name="l00296"></a><span class="lineno"><a class="line" href="classRNGClass.html#a7f1aab3c324f8e8a424d683425e0fcf8"> 296</a></span> <span class="keywordtype">void</span> <a class="code" href="classRNGClass.html#a7f1aab3c324f8e8a424d683425e0fcf8">RNGClass::begin</a>(<span class="keyword">const</span> <span class="keywordtype">char</span> *tag, <span class="keywordtype">int</span> eepromAddress)</div>
|
||||
<div class="line"><a name="l00297"></a><span class="lineno"> 297</span> {</div>
|
||||
<div class="line"><a name="l00298"></a><span class="lineno"> 298</span>  <span class="comment">// Save the EEPROM address for use by save().</span></div>
|
||||
<div class="line"><a name="l00299"></a><span class="lineno"> 299</span>  address = eepromAddress;</div>
|
||||
<div class="line"><a name="l00300"></a><span class="lineno"> 300</span> </div>
|
||||
<div class="line"><a name="l00301"></a><span class="lineno"> 301</span>  <span class="comment">// Initialize the ChaCha20 input block from the saved seed.</span></div>
|
||||
<div class="line"><a name="l00302"></a><span class="lineno"> 302</span>  memcpy_P(block, tagRNG, <span class="keyword">sizeof</span>(tagRNG));</div>
|
||||
<div class="line"><a name="l00303"></a><span class="lineno"> 303</span>  memcpy_P(block + 4, initRNG, <span class="keyword">sizeof</span>(initRNG));</div>
|
||||
<div class="line"><a name="l00304"></a><span class="lineno"> 304</span> <span class="preprocessor">#if defined(RNG_EEPROM)</span></div>
|
||||
<div class="line"><a name="l00305"></a><span class="lineno"> 305</span> <span class="preprocessor"></span> <span class="keywordflow">if</span> (eeprom_read_byte((<span class="keyword">const</span> uint8_t *)address) == <span class="charliteral">'S'</span>) {</div>
|
||||
<div class="line"><a name="l00306"></a><span class="lineno"> 306</span>  <span class="comment">// We have a saved seed: XOR it with the initialization block.</span></div>
|
||||
<div class="line"><a name="l00307"></a><span class="lineno"> 307</span>  <span class="keywordflow">for</span> (<span class="keywordtype">int</span> posn = 0; posn < 12; ++posn) {</div>
|
||||
<div class="line"><a name="l00308"></a><span class="lineno"> 308</span>  block[posn + 4] ^=</div>
|
||||
<div class="line"><a name="l00309"></a><span class="lineno"> 309</span>  eeprom_read_dword((<span class="keyword">const</span> uint32_t *)(address + posn * 4 + 1));</div>
|
||||
<div class="line"><a name="l00310"></a><span class="lineno"> 310</span>  }</div>
|
||||
<div class="line"><a name="l00311"></a><span class="lineno"> 311</span>  }</div>
|
||||
<div class="line"><a name="l00312"></a><span class="lineno"> 312</span> <span class="preprocessor">#elif defined(RNG_DUE_TRNG)</span></div>
|
||||
<div class="line"><a name="l00313"></a><span class="lineno"> 313</span> <span class="preprocessor"></span> <span class="comment">// Do we have a seed saved in the last page of flash memory on the Due?</span></div>
|
||||
<div class="line"><a name="l00314"></a><span class="lineno"> 314</span>  <span class="keywordtype">int</span> posn, counter;</div>
|
||||
<div class="line"><a name="l00315"></a><span class="lineno"> 315</span>  <span class="keywordflow">if</span> (((<span class="keyword">const</span> uint32_t *)RNG_SEED_ADDR)[0] == <span class="charliteral">'S'</span>) {</div>
|
||||
<div class="line"><a name="l00316"></a><span class="lineno"> 316</span>  <span class="comment">// XOR the saved seed with the initialization block.</span></div>
|
||||
<div class="line"><a name="l00317"></a><span class="lineno"> 317</span>  <span class="keywordflow">for</span> (posn = 0; posn < 12; ++posn)</div>
|
||||
<div class="line"><a name="l00318"></a><span class="lineno"> 318</span>  block[posn + 4] ^= ((<span class="keyword">const</span> uint32_t *)RNG_SEED_ADDR)[posn + 1];</div>
|
||||
<div class="line"><a name="l00319"></a><span class="lineno"> 319</span>  }</div>
|
||||
<div class="line"><a name="l00262"></a><span class="lineno"> 262</span>  <span class="comment">// Re-enable interrupts. The watchdog should be stopped.</span></div>
|
||||
<div class="line"><a name="l00263"></a><span class="lineno"> 263</span>  sei();</div>
|
||||
<div class="line"><a name="l00264"></a><span class="lineno"> 264</span> <span class="preprocessor">#endif</span></div>
|
||||
<div class="line"><a name="l00265"></a><span class="lineno"> 265</span> <span class="preprocessor"></span> clean(block);</div>
|
||||
<div class="line"><a name="l00266"></a><span class="lineno"> 266</span>  clean(stream);</div>
|
||||
<div class="line"><a name="l00267"></a><span class="lineno"> 267</span> }</div>
|
||||
<div class="line"><a name="l00268"></a><span class="lineno"> 268</span> </div>
|
||||
<div class="line"><a name="l00269"></a><span class="lineno"> 269</span> <span class="preprocessor">#if defined(RNG_DUE_TRNG)</span></div>
|
||||
<div class="line"><a name="l00270"></a><span class="lineno"> 270</span> <span class="preprocessor"></span></div>
|
||||
<div class="line"><a name="l00271"></a><span class="lineno"> 271</span> <span class="comment">// Find the flash memory of interest. Allow for the possibility</span></div>
|
||||
<div class="line"><a name="l00272"></a><span class="lineno"> 272</span> <span class="comment">// of other SAM-based Arduino variants in the future.</span></div>
|
||||
<div class="line"><a name="l00273"></a><span class="lineno"> 273</span> <span class="preprocessor">#if defined(IFLASH1_ADDR)</span></div>
|
||||
<div class="line"><a name="l00274"></a><span class="lineno"> 274</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_FLASH_ADDR IFLASH1_ADDR</span></div>
|
||||
<div class="line"><a name="l00275"></a><span class="lineno"> 275</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_FLASH_SIZE IFLASH1_SIZE</span></div>
|
||||
<div class="line"><a name="l00276"></a><span class="lineno"> 276</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_FLASH_PAGE_SIZE IFLASH1_PAGE_SIZE</span></div>
|
||||
<div class="line"><a name="l00277"></a><span class="lineno"> 277</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_EFC EFC1</span></div>
|
||||
<div class="line"><a name="l00278"></a><span class="lineno"> 278</span> <span class="preprocessor"></span><span class="preprocessor">#elif defined(IFLASH0_ADDR)</span></div>
|
||||
<div class="line"><a name="l00279"></a><span class="lineno"> 279</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_FLASH_ADDR IFLASH0_ADDR</span></div>
|
||||
<div class="line"><a name="l00280"></a><span class="lineno"> 280</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_FLASH_SIZE IFLASH0_SIZE</span></div>
|
||||
<div class="line"><a name="l00281"></a><span class="lineno"> 281</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_FLASH_PAGE_SIZE IFLASH0_PAGE_SIZE</span></div>
|
||||
<div class="line"><a name="l00282"></a><span class="lineno"> 282</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_EFC EFC0</span></div>
|
||||
<div class="line"><a name="l00283"></a><span class="lineno"> 283</span> <span class="preprocessor"></span><span class="preprocessor">#else</span></div>
|
||||
<div class="line"><a name="l00284"></a><span class="lineno"> 284</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_FLASH_ADDR IFLASH_ADDR</span></div>
|
||||
<div class="line"><a name="l00285"></a><span class="lineno"> 285</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_FLASH_SIZE IFLASH_SIZE</span></div>
|
||||
<div class="line"><a name="l00286"></a><span class="lineno"> 286</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_FLASH_PAGE_SIZE IFLASH_PAGE_SIZE</span></div>
|
||||
<div class="line"><a name="l00287"></a><span class="lineno"> 287</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_EFC EFC</span></div>
|
||||
<div class="line"><a name="l00288"></a><span class="lineno"> 288</span> <span class="preprocessor"></span><span class="preprocessor">#endif</span></div>
|
||||
<div class="line"><a name="l00289"></a><span class="lineno"> 289</span> <span class="preprocessor"></span></div>
|
||||
<div class="line"><a name="l00290"></a><span class="lineno"> 290</span> <span class="comment">// Address of the flash page to use for saving the seed on the Due.</span></div>
|
||||
<div class="line"><a name="l00291"></a><span class="lineno"> 291</span> <span class="comment">// All SAM variants have a page size of 256 bytes or greater so there is</span></div>
|
||||
<div class="line"><a name="l00292"></a><span class="lineno"> 292</span> <span class="comment">// plenty of room for the 48 byte seed in the last page of flash memory.</span></div>
|
||||
<div class="line"><a name="l00293"></a><span class="lineno"> 293</span> <span class="preprocessor">#define RNG_SEED_ADDR (RNG_FLASH_ADDR + RNG_FLASH_SIZE - RNG_FLASH_PAGE_SIZE)</span></div>
|
||||
<div class="line"><a name="l00294"></a><span class="lineno"> 294</span> <span class="preprocessor"></span><span class="preprocessor">#define RNG_SEED_PAGE ((RNG_FLASH_SIZE / RNG_FLASH_PAGE_SIZE) - 1)</span></div>
|
||||
<div class="line"><a name="l00295"></a><span class="lineno"> 295</span> <span class="preprocessor"></span></div>
|
||||
<div class="line"><a name="l00296"></a><span class="lineno"> 296</span> <span class="comment">// Stir in the unique identifier for the Arduino Due's CPU.</span></div>
|
||||
<div class="line"><a name="l00297"></a><span class="lineno"> 297</span> <span class="comment">// This function must be in RAM because programs running out of</span></div>
|
||||
<div class="line"><a name="l00298"></a><span class="lineno"> 298</span> <span class="comment">// flash memory are not allowed to access the unique identifier.</span></div>
|
||||
<div class="line"><a name="l00299"></a><span class="lineno"> 299</span> <span class="comment">// Info from: http://forum.arduino.cc/index.php?topic=289190.0</span></div>
|
||||
<div class="line"><a name="l00300"></a><span class="lineno"> 300</span> __attribute__((section(<span class="stringliteral">".ramfunc"</span>)))</div>
|
||||
<div class="line"><a name="l00301"></a><span class="lineno"> 301</span> static <span class="keywordtype">void</span> stirUniqueIdentifier(<span class="keywordtype">void</span>)</div>
|
||||
<div class="line"><a name="l00302"></a><span class="lineno"> 302</span> {</div>
|
||||
<div class="line"><a name="l00303"></a><span class="lineno"> 303</span>  uint32_t <span class="keywordtype">id</span>[4];</div>
|
||||
<div class="line"><a name="l00304"></a><span class="lineno"> 304</span> </div>
|
||||
<div class="line"><a name="l00305"></a><span class="lineno"> 305</span>  <span class="comment">// Start Read Unique Identifier.</span></div>
|
||||
<div class="line"><a name="l00306"></a><span class="lineno"> 306</span>  RNG_EFC->EEFC_FCR = (0x5A << 24) | EFC_FCMD_STUI;</div>
|
||||
<div class="line"><a name="l00307"></a><span class="lineno"> 307</span>  <span class="keywordflow">while</span> ((RNG_EFC->EEFC_FSR & EEFC_FSR_FRDY) != 0)</div>
|
||||
<div class="line"><a name="l00308"></a><span class="lineno"> 308</span>  ; <span class="comment">// do nothing until FRDY falls.</span></div>
|
||||
<div class="line"><a name="l00309"></a><span class="lineno"> 309</span> </div>
|
||||
<div class="line"><a name="l00310"></a><span class="lineno"> 310</span>  <span class="comment">// Read the identifier.</span></div>
|
||||
<div class="line"><a name="l00311"></a><span class="lineno"> 311</span>  <span class="keywordtype">id</span>[0] = *((<span class="keyword">const</span> uint32_t *)RNG_FLASH_ADDR);</div>
|
||||
<div class="line"><a name="l00312"></a><span class="lineno"> 312</span>  <span class="keywordtype">id</span>[1] = *((<span class="keyword">const</span> uint32_t *)(RNG_FLASH_ADDR + 4));</div>
|
||||
<div class="line"><a name="l00313"></a><span class="lineno"> 313</span>  <span class="keywordtype">id</span>[2] = *((<span class="keyword">const</span> uint32_t *)(RNG_FLASH_ADDR + 8));</div>
|
||||
<div class="line"><a name="l00314"></a><span class="lineno"> 314</span>  <span class="keywordtype">id</span>[3] = *((<span class="keyword">const</span> uint32_t *)(RNG_FLASH_ADDR + 12));</div>
|
||||
<div class="line"><a name="l00315"></a><span class="lineno"> 315</span> </div>
|
||||
<div class="line"><a name="l00316"></a><span class="lineno"> 316</span>  <span class="comment">// Stop Read Unique Identifier.</span></div>
|
||||
<div class="line"><a name="l00317"></a><span class="lineno"> 317</span>  RNG_EFC->EEFC_FCR = (0x5A << 24) | EFC_FCMD_SPUI;</div>
|
||||
<div class="line"><a name="l00318"></a><span class="lineno"> 318</span>  <span class="keywordflow">while</span> ((RNG_EFC->EEFC_FSR & EEFC_FSR_FRDY) == 0)</div>
|
||||
<div class="line"><a name="l00319"></a><span class="lineno"> 319</span>  ; <span class="comment">// do nothing until FRDY rises.</span></div>
|
||||
<div class="line"><a name="l00320"></a><span class="lineno"> 320</span> </div>
|
||||
<div class="line"><a name="l00321"></a><span class="lineno"> 321</span>  <span class="comment">// If the device has just been reprogrammed, there will be no saved seed.</span></div>
|
||||
<div class="line"><a name="l00322"></a><span class="lineno"> 322</span>  <span class="comment">// XOR the initialization block with some output from the CPU's TRNG</span></div>
|
||||
<div class="line"><a name="l00323"></a><span class="lineno"> 323</span>  <span class="comment">// to permute the state in a first boot situation after reprogramming.</span></div>
|
||||
<div class="line"><a name="l00324"></a><span class="lineno"> 324</span>  pmc_enable_periph_clk(ID_TRNG);</div>
|
||||
<div class="line"><a name="l00325"></a><span class="lineno"> 325</span>  REG_TRNG_CR = TRNG_CR_KEY(0x524E47) | TRNG_CR_ENABLE;</div>
|
||||
<div class="line"><a name="l00326"></a><span class="lineno"> 326</span>  REG_TRNG_IDR = TRNG_IDR_DATRDY; <span class="comment">// Disable interrupts - we will poll.</span></div>
|
||||
<div class="line"><a name="l00327"></a><span class="lineno"> 327</span>  <span class="keywordflow">for</span> (posn = 0; posn < 12; ++posn) {</div>
|
||||
<div class="line"><a name="l00328"></a><span class="lineno"> 328</span>  <span class="comment">// According to the documentation the TRNG should produce a new</span></div>
|
||||
<div class="line"><a name="l00329"></a><span class="lineno"> 329</span>  <span class="comment">// 32-bit random value every 84 clock cycles. If it still hasn't</span></div>
|
||||
<div class="line"><a name="l00330"></a><span class="lineno"> 330</span>  <span class="comment">// produced a value after 200 iterations, then assume that the</span></div>
|
||||
<div class="line"><a name="l00331"></a><span class="lineno"> 331</span>  <span class="comment">// TRNG is not producing output and stop.</span></div>
|
||||
<div class="line"><a name="l00332"></a><span class="lineno"> 332</span>  <span class="keywordflow">for</span> (counter = 0; counter < 200; ++counter) {</div>
|
||||
<div class="line"><a name="l00333"></a><span class="lineno"> 333</span>  <span class="keywordflow">if</span> ((REG_TRNG_ISR & TRNG_ISR_DATRDY) != 0)</div>
|
||||
<div class="line"><a name="l00334"></a><span class="lineno"> 334</span>  <span class="keywordflow">break</span>;</div>
|
||||
<div class="line"><a name="l00335"></a><span class="lineno"> 335</span>  }</div>
|
||||
<div class="line"><a name="l00336"></a><span class="lineno"> 336</span>  <span class="keywordflow">if</span> (counter >= 200)</div>
|
||||
<div class="line"><a name="l00337"></a><span class="lineno"> 337</span>  <span class="keywordflow">break</span>;</div>
|
||||
<div class="line"><a name="l00338"></a><span class="lineno"> 338</span>  block[posn + 4] ^= REG_TRNG_ODATA;</div>
|
||||
<div class="line"><a name="l00339"></a><span class="lineno"> 339</span>  }</div>
|
||||
<div class="line"><a name="l00340"></a><span class="lineno"> 340</span> <span class="preprocessor">#endif</span></div>
|
||||
<div class="line"><a name="l00341"></a><span class="lineno"> 341</span> <span class="preprocessor"></span></div>
|
||||
<div class="line"><a name="l00342"></a><span class="lineno"> 342</span>  <span class="comment">// No entropy credits for the saved seed.</span></div>
|
||||
<div class="line"><a name="l00343"></a><span class="lineno"> 343</span>  credits = 0;</div>
|
||||
<div class="line"><a name="l00344"></a><span class="lineno"> 344</span> </div>
|
||||
<div class="line"><a name="l00345"></a><span class="lineno"> 345</span>  <span class="comment">// Trigger an automatic save once the entropy credits max out.</span></div>
|
||||
<div class="line"><a name="l00346"></a><span class="lineno"> 346</span>  firstSave = 1;</div>
|
||||
<div class="line"><a name="l00347"></a><span class="lineno"> 347</span> </div>
|
||||
<div class="line"><a name="l00348"></a><span class="lineno"> 348</span>  <span class="comment">// Rekey the random number generator immediately.</span></div>
|
||||
<div class="line"><a name="l00349"></a><span class="lineno"> 349</span>  rekey();</div>
|
||||
<div class="line"><a name="l00350"></a><span class="lineno"> 350</span> </div>
|
||||
<div class="line"><a name="l00351"></a><span class="lineno"> 351</span>  <span class="comment">// Stir in the supplied tag data but don't credit any entropy to it.</span></div>
|
||||
<div class="line"><a name="l00352"></a><span class="lineno"> 352</span>  <span class="keywordflow">if</span> (tag)</div>
|
||||
<div class="line"><a name="l00353"></a><span class="lineno"> 353</span>  <a class="code" href="classRNGClass.html#ad99535ea23ae2fec55bdebb8c24def02">stir</a>((<span class="keyword">const</span> uint8_t *)tag, strlen(tag));</div>
|
||||
<div class="line"><a name="l00354"></a><span class="lineno"> 354</span> </div>
|
||||
<div class="line"><a name="l00355"></a><span class="lineno"> 355</span> <span class="preprocessor">#if defined(RNG_DUE_TRNG)</span></div>
|
||||
<div class="line"><a name="l00356"></a><span class="lineno"> 356</span> <span class="preprocessor"></span> <span class="comment">// Stir in the unique identifier for the CPU so that different</span></div>
|
||||
<div class="line"><a name="l00357"></a><span class="lineno"> 357</span>  <span class="comment">// devices will give different outputs even without seeding.</span></div>
|
||||
<div class="line"><a name="l00358"></a><span class="lineno"> 358</span>  stirUniqueIdentifier();</div>
|
||||
<div class="line"><a name="l00359"></a><span class="lineno"> 359</span> <span class="preprocessor">#endif</span></div>
|
||||
<div class="line"><a name="l00360"></a><span class="lineno"> 360</span> <span class="preprocessor"></span></div>
|
||||
<div class="line"><a name="l00361"></a><span class="lineno"> 361</span>  <span class="comment">// Re-save the seed to obliterate the previous value and to ensure</span></div>
|
||||
<div class="line"><a name="l00362"></a><span class="lineno"> 362</span>  <span class="comment">// that if the system is reset without a call to save() that we won't</span></div>
|
||||
<div class="line"><a name="l00363"></a><span class="lineno"> 363</span>  <span class="comment">// accidentally generate the same sequence of random data again.</span></div>
|
||||
<div class="line"><a name="l00364"></a><span class="lineno"> 364</span>  <a class="code" href="classRNGClass.html#a139584fb249148e2058d1d645d090db7">save</a>();</div>
|
||||
<div class="line"><a name="l00365"></a><span class="lineno"> 365</span> }</div>
|
||||
<div class="line"><a name="l00366"></a><span class="lineno"> 366</span> </div>
|
||||
<div class="line"><a name="l00379"></a><span class="lineno"><a class="line" href="classRNGClass.html#aacf23b192b0e4cc8726d9abe05f5a9db"> 379</a></span> <span class="keywordtype">void</span> <a class="code" href="classRNGClass.html#aacf23b192b0e4cc8726d9abe05f5a9db">RNGClass::addNoiseSource</a>(<a class="code" href="classNoiseSource.html">NoiseSource</a> &source)</div>
|
||||
<div class="line"><a name="l00380"></a><span class="lineno"> 380</span> {</div>
|
||||
<div class="line"><a name="l00381"></a><span class="lineno"> 381</span> <span class="preprocessor"> #define MAX_NOISE_SOURCES (sizeof(noiseSources) / sizeof(noiseSources[0]))</span></div>
|
||||
<div class="line"><a name="l00382"></a><span class="lineno"> 382</span> <span class="preprocessor"></span> <span class="keywordflow">if</span> (count < MAX_NOISE_SOURCES) {</div>
|
||||
<div class="line"><a name="l00383"></a><span class="lineno"> 383</span>  noiseSources[count++] = &source;</div>
|
||||
<div class="line"><a name="l00384"></a><span class="lineno"> 384</span>  source.<a class="code" href="classNoiseSource.html#a48d0efabd71ff6e557a0898be79c49ba">added</a>();</div>
|
||||
<div class="line"><a name="l00385"></a><span class="lineno"> 385</span>  }</div>
|
||||
<div class="line"><a name="l00386"></a><span class="lineno"> 386</span> }</div>
|
||||
<div class="line"><a name="l00387"></a><span class="lineno"> 387</span> </div>
|
||||
<div class="line"><a name="l00404"></a><span class="lineno"><a class="line" href="classRNGClass.html#a5848e87a5f2f0302c88b0377f0e3366d"> 404</a></span> <span class="keywordtype">void</span> <a class="code" href="classRNGClass.html#a5848e87a5f2f0302c88b0377f0e3366d">RNGClass::setAutoSaveTime</a>(uint16_t minutes)</div>
|
||||
<div class="line"><a name="l00405"></a><span class="lineno"> 405</span> {</div>
|
||||
<div class="line"><a name="l00406"></a><span class="lineno"> 406</span>  <span class="keywordflow">if</span> (!minutes)</div>
|
||||
<div class="line"><a name="l00407"></a><span class="lineno"> 407</span>  minutes = 1; <span class="comment">// Just in case.</span></div>
|
||||
<div class="line"><a name="l00408"></a><span class="lineno"> 408</span>  timeout = ((uint32_t)minutes) * 60000U;</div>
|
||||
<div class="line"><a name="l00409"></a><span class="lineno"> 409</span> }</div>
|
||||
<div class="line"><a name="l00321"></a><span class="lineno"> 321</span>  <span class="comment">// Stir the unique identifier into the entropy pool.</span></div>
|
||||
<div class="line"><a name="l00322"></a><span class="lineno"> 322</span>  RNG.<a class="code" href="classRNGClass.html#ad99535ea23ae2fec55bdebb8c24def02">stir</a>((uint8_t *)<span class="keywordtype">id</span>, <span class="keyword">sizeof</span>(<span class="keywordtype">id</span>));</div>
|
||||
<div class="line"><a name="l00323"></a><span class="lineno"> 323</span> }</div>
|
||||
<div class="line"><a name="l00324"></a><span class="lineno"> 324</span> </div>
|
||||
<div class="line"><a name="l00325"></a><span class="lineno"> 325</span> <span class="comment">// Erases the flash page containing the seed and then writes the new seed.</span></div>
|
||||
<div class="line"><a name="l00326"></a><span class="lineno"> 326</span> <span class="comment">// It is assumed the seed has already been loaded into the latch registers.</span></div>
|
||||
<div class="line"><a name="l00327"></a><span class="lineno"> 327</span> __attribute__((section(<span class="stringliteral">".ramfunc"</span>)))</div>
|
||||
<div class="line"><a name="l00328"></a><span class="lineno"> 328</span> static <span class="keywordtype">void</span> eraseAndWriteSeed()</div>
|
||||
<div class="line"><a name="l00329"></a><span class="lineno"> 329</span> {</div>
|
||||
<div class="line"><a name="l00330"></a><span class="lineno"> 330</span>  <span class="comment">// Execute the "Erase and Write Page" command.</span></div>
|
||||
<div class="line"><a name="l00331"></a><span class="lineno"> 331</span>  RNG_EFC->EEFC_FCR = (0x5A << 24) | (RNG_SEED_PAGE << 8) | EFC_FCMD_EWP;</div>
|
||||
<div class="line"><a name="l00332"></a><span class="lineno"> 332</span> </div>
|
||||
<div class="line"><a name="l00333"></a><span class="lineno"> 333</span>  <span class="comment">// Wait for the FRDY bit to be raised.</span></div>
|
||||
<div class="line"><a name="l00334"></a><span class="lineno"> 334</span>  <span class="keywordflow">while</span> ((RNG_EFC->EEFC_FSR & EEFC_FSR_FRDY) == 0)</div>
|
||||
<div class="line"><a name="l00335"></a><span class="lineno"> 335</span>  ; <span class="comment">// do nothing until FRDY rises.</span></div>
|
||||
<div class="line"><a name="l00336"></a><span class="lineno"> 336</span> }</div>
|
||||
<div class="line"><a name="l00337"></a><span class="lineno"> 337</span> </div>
|
||||
<div class="line"><a name="l00338"></a><span class="lineno"> 338</span> <span class="preprocessor">#endif</span></div>
|
||||
<div class="line"><a name="l00339"></a><span class="lineno"> 339</span> <span class="preprocessor"></span></div>
|
||||
<div class="line"><a name="l00359"></a><span class="lineno"><a class="line" href="classRNGClass.html#a7f1aab3c324f8e8a424d683425e0fcf8"> 359</a></span> <span class="keywordtype">void</span> <a class="code" href="classRNGClass.html#a7f1aab3c324f8e8a424d683425e0fcf8">RNGClass::begin</a>(<span class="keyword">const</span> <span class="keywordtype">char</span> *tag, <span class="keywordtype">int</span> eepromAddress)</div>
|
||||
<div class="line"><a name="l00360"></a><span class="lineno"> 360</span> {</div>
|
||||
<div class="line"><a name="l00361"></a><span class="lineno"> 361</span>  <span class="comment">// Save the EEPROM address for use by save().</span></div>
|
||||
<div class="line"><a name="l00362"></a><span class="lineno"> 362</span>  address = eepromAddress;</div>
|
||||
<div class="line"><a name="l00363"></a><span class="lineno"> 363</span> </div>
|
||||
<div class="line"><a name="l00364"></a><span class="lineno"> 364</span>  <span class="comment">// Initialize the ChaCha20 input block from the saved seed.</span></div>
|
||||
<div class="line"><a name="l00365"></a><span class="lineno"> 365</span>  memcpy_P(block, tagRNG, <span class="keyword">sizeof</span>(tagRNG));</div>
|
||||
<div class="line"><a name="l00366"></a><span class="lineno"> 366</span>  memcpy_P(block + 4, initRNG, <span class="keyword">sizeof</span>(initRNG));</div>
|
||||
<div class="line"><a name="l00367"></a><span class="lineno"> 367</span> <span class="preprocessor">#if defined(RNG_EEPROM)</span></div>
|
||||
<div class="line"><a name="l00368"></a><span class="lineno"> 368</span> <span class="preprocessor"></span> <span class="keywordflow">if</span> (eeprom_read_byte((<span class="keyword">const</span> uint8_t *)address) == <span class="charliteral">'S'</span>) {</div>
|
||||
<div class="line"><a name="l00369"></a><span class="lineno"> 369</span>  <span class="comment">// We have a saved seed: XOR it with the initialization block.</span></div>
|
||||
<div class="line"><a name="l00370"></a><span class="lineno"> 370</span>  <span class="keywordflow">for</span> (<span class="keywordtype">int</span> posn = 0; posn < 12; ++posn) {</div>
|
||||
<div class="line"><a name="l00371"></a><span class="lineno"> 371</span>  block[posn + 4] ^=</div>
|
||||
<div class="line"><a name="l00372"></a><span class="lineno"> 372</span>  eeprom_read_dword((<span class="keyword">const</span> uint32_t *)(address + posn * 4 + 1));</div>
|
||||
<div class="line"><a name="l00373"></a><span class="lineno"> 373</span>  }</div>
|
||||
<div class="line"><a name="l00374"></a><span class="lineno"> 374</span>  }</div>
|
||||
<div class="line"><a name="l00375"></a><span class="lineno"> 375</span> <span class="preprocessor">#elif defined(RNG_DUE_TRNG)</span></div>
|
||||
<div class="line"><a name="l00376"></a><span class="lineno"> 376</span> <span class="preprocessor"></span> <span class="comment">// Do we have a seed saved in the last page of flash memory on the Due?</span></div>
|
||||
<div class="line"><a name="l00377"></a><span class="lineno"> 377</span>  <span class="keywordtype">int</span> posn, counter;</div>
|
||||
<div class="line"><a name="l00378"></a><span class="lineno"> 378</span>  <span class="keywordflow">if</span> (((<span class="keyword">const</span> uint32_t *)RNG_SEED_ADDR)[0] == <span class="charliteral">'S'</span>) {</div>
|
||||
<div class="line"><a name="l00379"></a><span class="lineno"> 379</span>  <span class="comment">// XOR the saved seed with the initialization block.</span></div>
|
||||
<div class="line"><a name="l00380"></a><span class="lineno"> 380</span>  <span class="keywordflow">for</span> (posn = 0; posn < 12; ++posn)</div>
|
||||
<div class="line"><a name="l00381"></a><span class="lineno"> 381</span>  block[posn + 4] ^= ((<span class="keyword">const</span> uint32_t *)RNG_SEED_ADDR)[posn + 1];</div>
|
||||
<div class="line"><a name="l00382"></a><span class="lineno"> 382</span>  }</div>
|
||||
<div class="line"><a name="l00383"></a><span class="lineno"> 383</span> </div>
|
||||
<div class="line"><a name="l00384"></a><span class="lineno"> 384</span>  <span class="comment">// If the device has just been reprogrammed, there will be no saved seed.</span></div>
|
||||
<div class="line"><a name="l00385"></a><span class="lineno"> 385</span>  <span class="comment">// XOR the initialization block with some output from the CPU's TRNG</span></div>
|
||||
<div class="line"><a name="l00386"></a><span class="lineno"> 386</span>  <span class="comment">// to permute the state in a first boot situation after reprogramming.</span></div>
|
||||
<div class="line"><a name="l00387"></a><span class="lineno"> 387</span>  pmc_enable_periph_clk(ID_TRNG);</div>
|
||||
<div class="line"><a name="l00388"></a><span class="lineno"> 388</span>  REG_TRNG_CR = TRNG_CR_KEY(0x524E47) | TRNG_CR_ENABLE;</div>
|
||||
<div class="line"><a name="l00389"></a><span class="lineno"> 389</span>  REG_TRNG_IDR = TRNG_IDR_DATRDY; <span class="comment">// Disable interrupts - we will poll.</span></div>
|
||||
<div class="line"><a name="l00390"></a><span class="lineno"> 390</span>  <span class="keywordflow">for</span> (posn = 0; posn < 12; ++posn) {</div>
|
||||
<div class="line"><a name="l00391"></a><span class="lineno"> 391</span>  <span class="comment">// According to the documentation the TRNG should produce a new</span></div>
|
||||
<div class="line"><a name="l00392"></a><span class="lineno"> 392</span>  <span class="comment">// 32-bit random value every 84 clock cycles. If it still hasn't</span></div>
|
||||
<div class="line"><a name="l00393"></a><span class="lineno"> 393</span>  <span class="comment">// produced a value after 200 iterations, then assume that the</span></div>
|
||||
<div class="line"><a name="l00394"></a><span class="lineno"> 394</span>  <span class="comment">// TRNG is not producing output and stop.</span></div>
|
||||
<div class="line"><a name="l00395"></a><span class="lineno"> 395</span>  <span class="keywordflow">for</span> (counter = 0; counter < 200; ++counter) {</div>
|
||||
<div class="line"><a name="l00396"></a><span class="lineno"> 396</span>  <span class="keywordflow">if</span> ((REG_TRNG_ISR & TRNG_ISR_DATRDY) != 0)</div>
|
||||
<div class="line"><a name="l00397"></a><span class="lineno"> 397</span>  <span class="keywordflow">break</span>;</div>
|
||||
<div class="line"><a name="l00398"></a><span class="lineno"> 398</span>  }</div>
|
||||
<div class="line"><a name="l00399"></a><span class="lineno"> 399</span>  <span class="keywordflow">if</span> (counter >= 200)</div>
|
||||
<div class="line"><a name="l00400"></a><span class="lineno"> 400</span>  <span class="keywordflow">break</span>;</div>
|
||||
<div class="line"><a name="l00401"></a><span class="lineno"> 401</span>  block[posn + 4] ^= REG_TRNG_ODATA;</div>
|
||||
<div class="line"><a name="l00402"></a><span class="lineno"> 402</span>  }</div>
|
||||
<div class="line"><a name="l00403"></a><span class="lineno"> 403</span> <span class="preprocessor">#endif</span></div>
|
||||
<div class="line"><a name="l00404"></a><span class="lineno"> 404</span> <span class="preprocessor"></span></div>
|
||||
<div class="line"><a name="l00405"></a><span class="lineno"> 405</span>  <span class="comment">// No entropy credits for the saved seed.</span></div>
|
||||
<div class="line"><a name="l00406"></a><span class="lineno"> 406</span>  credits = 0;</div>
|
||||
<div class="line"><a name="l00407"></a><span class="lineno"> 407</span> </div>
|
||||
<div class="line"><a name="l00408"></a><span class="lineno"> 408</span>  <span class="comment">// Trigger an automatic save once the entropy credits max out.</span></div>
|
||||
<div class="line"><a name="l00409"></a><span class="lineno"> 409</span>  firstSave = 1;</div>
|
||||
<div class="line"><a name="l00410"></a><span class="lineno"> 410</span> </div>
|
||||
<div class="line"><a name="l00428"></a><span class="lineno"><a class="line" href="classRNGClass.html#a418a833cf18198fd7e5d6dbd78c99c29"> 428</a></span> <span class="keywordtype">void</span> <a class="code" href="classRNGClass.html#a418a833cf18198fd7e5d6dbd78c99c29">RNGClass::rand</a>(uint8_t *data, <span class="keywordtype">size_t</span> len)</div>
|
||||
<div class="line"><a name="l00429"></a><span class="lineno"> 429</span> {</div>
|
||||
<div class="line"><a name="l00430"></a><span class="lineno"> 430</span>  <span class="comment">// Decrease the amount of entropy in the pool.</span></div>
|
||||
<div class="line"><a name="l00431"></a><span class="lineno"> 431</span>  <span class="keywordflow">if</span> (len > (credits / 8))</div>
|
||||
<div class="line"><a name="l00432"></a><span class="lineno"> 432</span>  credits = 0;</div>
|
||||
<div class="line"><a name="l00433"></a><span class="lineno"> 433</span>  <span class="keywordflow">else</span></div>
|
||||
<div class="line"><a name="l00434"></a><span class="lineno"> 434</span>  credits -= len * 8;</div>
|
||||
<div class="line"><a name="l00435"></a><span class="lineno"> 435</span> </div>
|
||||
<div class="line"><a name="l00436"></a><span class="lineno"> 436</span>  <span class="comment">// Generate the random data.</span></div>
|
||||
<div class="line"><a name="l00437"></a><span class="lineno"> 437</span>  uint8_t count = 0;</div>
|
||||
<div class="line"><a name="l00438"></a><span class="lineno"> 438</span>  <span class="keywordflow">while</span> (len > 0) {</div>
|
||||
<div class="line"><a name="l00439"></a><span class="lineno"> 439</span>  <span class="comment">// Force a rekey if we have generated too many blocks in this request.</span></div>
|
||||
<div class="line"><a name="l00440"></a><span class="lineno"> 440</span>  <span class="keywordflow">if</span> (count >= RNG_REKEY_BLOCKS) {</div>
|
||||
<div class="line"><a name="l00441"></a><span class="lineno"> 441</span>  rekey();</div>
|
||||
<div class="line"><a name="l00442"></a><span class="lineno"> 442</span>  count = 1;</div>
|
||||
<div class="line"><a name="l00443"></a><span class="lineno"> 443</span>  } <span class="keywordflow">else</span> {</div>
|
||||
<div class="line"><a name="l00444"></a><span class="lineno"> 444</span>  ++count;</div>
|
||||
<div class="line"><a name="l00445"></a><span class="lineno"> 445</span>  }</div>
|
||||
<div class="line"><a name="l00411"></a><span class="lineno"> 411</span>  <span class="comment">// Rekey the random number generator immediately.</span></div>
|
||||
<div class="line"><a name="l00412"></a><span class="lineno"> 412</span>  rekey();</div>
|
||||
<div class="line"><a name="l00413"></a><span class="lineno"> 413</span> </div>
|
||||
<div class="line"><a name="l00414"></a><span class="lineno"> 414</span>  <span class="comment">// Stir in the supplied tag data but don't credit any entropy to it.</span></div>
|
||||
<div class="line"><a name="l00415"></a><span class="lineno"> 415</span>  <span class="keywordflow">if</span> (tag)</div>
|
||||
<div class="line"><a name="l00416"></a><span class="lineno"> 416</span>  <a class="code" href="classRNGClass.html#ad99535ea23ae2fec55bdebb8c24def02">stir</a>((<span class="keyword">const</span> uint8_t *)tag, strlen(tag));</div>
|
||||
<div class="line"><a name="l00417"></a><span class="lineno"> 417</span> </div>
|
||||
<div class="line"><a name="l00418"></a><span class="lineno"> 418</span> <span class="preprocessor">#if defined(RNG_DUE_TRNG)</span></div>
|
||||
<div class="line"><a name="l00419"></a><span class="lineno"> 419</span> <span class="preprocessor"></span> <span class="comment">// Stir in the unique identifier for the CPU so that different</span></div>
|
||||
<div class="line"><a name="l00420"></a><span class="lineno"> 420</span>  <span class="comment">// devices will give different outputs even without seeding.</span></div>
|
||||
<div class="line"><a name="l00421"></a><span class="lineno"> 421</span>  stirUniqueIdentifier();</div>
|
||||
<div class="line"><a name="l00422"></a><span class="lineno"> 422</span> <span class="preprocessor">#endif</span></div>
|
||||
<div class="line"><a name="l00423"></a><span class="lineno"> 423</span> <span class="preprocessor"></span></div>
|
||||
<div class="line"><a name="l00424"></a><span class="lineno"> 424</span> <span class="preprocessor">#if defined(RNG_WATCHDOG)</span></div>
|
||||
<div class="line"><a name="l00425"></a><span class="lineno"> 425</span> <span class="preprocessor"></span> <span class="comment">// Disable interrupts and reset the watchdog.</span></div>
|
||||
<div class="line"><a name="l00426"></a><span class="lineno"> 426</span>  cli();</div>
|
||||
<div class="line"><a name="l00427"></a><span class="lineno"> 427</span>  wdt_reset();</div>
|
||||
<div class="line"><a name="l00428"></a><span class="lineno"> 428</span> </div>
|
||||
<div class="line"><a name="l00429"></a><span class="lineno"> 429</span>  <span class="comment">// Clear the "reset due to watchdog" flag.</span></div>
|
||||
<div class="line"><a name="l00430"></a><span class="lineno"> 430</span>  MCUSR &= ~(1 << WDRF);</div>
|
||||
<div class="line"><a name="l00431"></a><span class="lineno"> 431</span> </div>
|
||||
<div class="line"><a name="l00432"></a><span class="lineno"> 432</span>  <span class="comment">// Enable the watchdog with the smallest duration (16ms)</span></div>
|
||||
<div class="line"><a name="l00433"></a><span class="lineno"> 433</span>  <span class="comment">// and interrupt-only mode.</span></div>
|
||||
<div class="line"><a name="l00434"></a><span class="lineno"> 434</span>  _WD_CONTROL_REG |= (1 << _WD_CHANGE_BIT) | (1 << WDE);</div>
|
||||
<div class="line"><a name="l00435"></a><span class="lineno"> 435</span>  _WD_CONTROL_REG = (1 << WDIE);</div>
|
||||
<div class="line"><a name="l00436"></a><span class="lineno"> 436</span> </div>
|
||||
<div class="line"><a name="l00437"></a><span class="lineno"> 437</span>  <span class="comment">// Re-enable interrupts. The watchdog should be running.</span></div>
|
||||
<div class="line"><a name="l00438"></a><span class="lineno"> 438</span>  sei();</div>
|
||||
<div class="line"><a name="l00439"></a><span class="lineno"> 439</span> <span class="preprocessor">#endif</span></div>
|
||||
<div class="line"><a name="l00440"></a><span class="lineno"> 440</span> <span class="preprocessor"></span></div>
|
||||
<div class="line"><a name="l00441"></a><span class="lineno"> 441</span>  <span class="comment">// Re-save the seed to obliterate the previous value and to ensure</span></div>
|
||||
<div class="line"><a name="l00442"></a><span class="lineno"> 442</span>  <span class="comment">// that if the system is reset without a call to save() that we won't</span></div>
|
||||
<div class="line"><a name="l00443"></a><span class="lineno"> 443</span>  <span class="comment">// accidentally generate the same sequence of random data again.</span></div>
|
||||
<div class="line"><a name="l00444"></a><span class="lineno"> 444</span>  <a class="code" href="classRNGClass.html#a139584fb249148e2058d1d645d090db7">save</a>();</div>
|
||||
<div class="line"><a name="l00445"></a><span class="lineno"> 445</span> }</div>
|
||||
<div class="line"><a name="l00446"></a><span class="lineno"> 446</span> </div>
|
||||
<div class="line"><a name="l00447"></a><span class="lineno"> 447</span>  <span class="comment">// Increment the low counter word and generate a new keystream block.</span></div>
|
||||
<div class="line"><a name="l00448"></a><span class="lineno"> 448</span>  ++(block[12]);</div>
|
||||
<div class="line"><a name="l00449"></a><span class="lineno"> 449</span>  <a class="code" href="classChaCha.html#a41ac3262e52ff49dcd916d0b3b2e2038">ChaCha::hashCore</a>(stream, block, RNG_ROUNDS);</div>
|
||||
<div class="line"><a name="l00450"></a><span class="lineno"> 450</span> </div>
|
||||
<div class="line"><a name="l00451"></a><span class="lineno"> 451</span>  <span class="comment">// Copy the data to the return buffer.</span></div>
|
||||
<div class="line"><a name="l00452"></a><span class="lineno"> 452</span>  <span class="keywordflow">if</span> (len < 64) {</div>
|
||||
<div class="line"><a name="l00453"></a><span class="lineno"> 453</span>  memcpy(data, stream, len);</div>
|
||||
<div class="line"><a name="l00454"></a><span class="lineno"> 454</span>  <span class="keywordflow">break</span>;</div>
|
||||
<div class="line"><a name="l00455"></a><span class="lineno"> 455</span>  } <span class="keywordflow">else</span> {</div>
|
||||
<div class="line"><a name="l00456"></a><span class="lineno"> 456</span>  memcpy(data, stream, 64);</div>
|
||||
<div class="line"><a name="l00457"></a><span class="lineno"> 457</span>  data += 64;</div>
|
||||
<div class="line"><a name="l00458"></a><span class="lineno"> 458</span>  len -= 64;</div>
|
||||
<div class="line"><a name="l00459"></a><span class="lineno"> 459</span>  }</div>
|
||||
<div class="line"><a name="l00460"></a><span class="lineno"> 460</span>  }</div>
|
||||
<div class="line"><a name="l00461"></a><span class="lineno"> 461</span> </div>
|
||||
<div class="line"><a name="l00462"></a><span class="lineno"> 462</span>  <span class="comment">// Force a rekey after every request.</span></div>
|
||||
<div class="line"><a name="l00463"></a><span class="lineno"> 463</span>  rekey();</div>
|
||||
<div class="line"><a name="l00464"></a><span class="lineno"> 464</span> }</div>
|
||||
<div class="line"><a name="l00465"></a><span class="lineno"> 465</span> </div>
|
||||
<div class="line"><a name="l00505"></a><span class="lineno"><a class="line" href="classRNGClass.html#a49e3231ba65a5e4b045bc90976e0a659"> 505</a></span> <span class="keywordtype">bool</span> <a class="code" href="classRNGClass.html#a49e3231ba65a5e4b045bc90976e0a659">RNGClass::available</a>(<span class="keywordtype">size_t</span> len)<span class="keyword"> const</span></div>
|
||||
<div class="line"><a name="l00506"></a><span class="lineno"> 506</span> <span class="keyword"></span>{</div>
|
||||
<div class="line"><a name="l00507"></a><span class="lineno"> 507</span>  <span class="keywordflow">if</span> (len >= (RNG_MAX_CREDITS / 8))</div>
|
||||
<div class="line"><a name="l00508"></a><span class="lineno"> 508</span>  <span class="keywordflow">return</span> credits >= RNG_MAX_CREDITS;</div>
|
||||
<div class="line"><a name="l00509"></a><span class="lineno"> 509</span>  <span class="keywordflow">else</span></div>
|
||||
<div class="line"><a name="l00510"></a><span class="lineno"> 510</span>  <span class="keywordflow">return</span> len <= (credits / 8);</div>
|
||||
<div class="line"><a name="l00511"></a><span class="lineno"> 511</span> }</div>
|
||||
<div class="line"><a name="l00512"></a><span class="lineno"> 512</span> </div>
|
||||
<div class="line"><a name="l00538"></a><span class="lineno"><a class="line" href="classRNGClass.html#ad99535ea23ae2fec55bdebb8c24def02"> 538</a></span> <span class="keywordtype">void</span> <a class="code" href="classRNGClass.html#ad99535ea23ae2fec55bdebb8c24def02">RNGClass::stir</a>(<span class="keyword">const</span> uint8_t *data, <span class="keywordtype">size_t</span> len, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> credit)</div>
|
||||
<div class="line"><a name="l00539"></a><span class="lineno"> 539</span> {</div>
|
||||
<div class="line"><a name="l00540"></a><span class="lineno"> 540</span>  <span class="comment">// Increase the entropy credit.</span></div>
|
||||
<div class="line"><a name="l00541"></a><span class="lineno"> 541</span>  <span class="keywordflow">if</span> ((credit / 8) >= len)</div>
|
||||
<div class="line"><a name="l00542"></a><span class="lineno"> 542</span>  credit = len * 8;</div>
|
||||
<div class="line"><a name="l00543"></a><span class="lineno"> 543</span>  <span class="keywordflow">if</span> ((RNG_MAX_CREDITS - credits) > credit)</div>
|
||||
<div class="line"><a name="l00544"></a><span class="lineno"> 544</span>  credits += credit;</div>
|
||||
<div class="line"><a name="l00545"></a><span class="lineno"> 545</span>  <span class="keywordflow">else</span></div>
|
||||
<div class="line"><a name="l00546"></a><span class="lineno"> 546</span>  credits = RNG_MAX_CREDITS;</div>
|
||||
<div class="line"><a name="l00547"></a><span class="lineno"> 547</span> </div>
|
||||
<div class="line"><a name="l00548"></a><span class="lineno"> 548</span>  <span class="comment">// Process the supplied input data.</span></div>
|
||||
<div class="line"><a name="l00549"></a><span class="lineno"> 549</span>  <span class="keywordflow">if</span> (len > 0) {</div>
|
||||
<div class="line"><a name="l00550"></a><span class="lineno"> 550</span>  <span class="comment">// XOR the data with the ChaCha input block in 48 byte</span></div>
|
||||
<div class="line"><a name="l00551"></a><span class="lineno"> 551</span>  <span class="comment">// chunks and rekey the ChaCha cipher for each chunk to mix</span></div>
|
||||
<div class="line"><a name="l00552"></a><span class="lineno"> 552</span>  <span class="comment">// the data in. This should scatter any "true entropy" in</span></div>
|
||||
<div class="line"><a name="l00553"></a><span class="lineno"> 553</span>  <span class="comment">// the input across the entire block.</span></div>
|
||||
<div class="line"><a name="l00554"></a><span class="lineno"> 554</span>  <span class="keywordflow">while</span> (len > 0) {</div>
|
||||
<div class="line"><a name="l00555"></a><span class="lineno"> 555</span>  <span class="keywordtype">size_t</span> templen = len;</div>
|
||||
<div class="line"><a name="l00556"></a><span class="lineno"> 556</span>  <span class="keywordflow">if</span> (templen > 48)</div>
|
||||
<div class="line"><a name="l00557"></a><span class="lineno"> 557</span>  templen = 48;</div>
|
||||
<div class="line"><a name="l00558"></a><span class="lineno"> 558</span>  uint8_t *output = ((uint8_t *)block) + 16;</div>
|
||||
<div class="line"><a name="l00559"></a><span class="lineno"> 559</span>  len -= templen;</div>
|
||||
<div class="line"><a name="l00560"></a><span class="lineno"> 560</span>  <span class="keywordflow">while</span> (templen > 0) {</div>
|
||||
<div class="line"><a name="l00561"></a><span class="lineno"> 561</span>  *output++ ^= *data++;</div>
|
||||
<div class="line"><a name="l00562"></a><span class="lineno"> 562</span>  --templen;</div>
|
||||
<div class="line"><a name="l00563"></a><span class="lineno"> 563</span>  }</div>
|
||||
<div class="line"><a name="l00564"></a><span class="lineno"> 564</span>  rekey();</div>
|
||||
<div class="line"><a name="l00565"></a><span class="lineno"> 565</span>  }</div>
|
||||
<div class="line"><a name="l00566"></a><span class="lineno"> 566</span>  } <span class="keywordflow">else</span> {</div>
|
||||
<div class="line"><a name="l00567"></a><span class="lineno"> 567</span>  <span class="comment">// There was no input data, so just force a rekey so we</span></div>
|
||||
<div class="line"><a name="l00568"></a><span class="lineno"> 568</span>  <span class="comment">// get some mixing of the state even without new data.</span></div>
|
||||
<div class="line"><a name="l00569"></a><span class="lineno"> 569</span>  rekey();</div>
|
||||
<div class="line"><a name="l00570"></a><span class="lineno"> 570</span>  }</div>
|
||||
<div class="line"><a name="l00571"></a><span class="lineno"> 571</span> </div>
|
||||
<div class="line"><a name="l00572"></a><span class="lineno"> 572</span>  <span class="comment">// Save if this is the first time we have reached max entropy.</span></div>
|
||||
<div class="line"><a name="l00573"></a><span class="lineno"> 573</span>  <span class="comment">// This provides some protection if the system is powered off before</span></div>
|
||||
<div class="line"><a name="l00574"></a><span class="lineno"> 574</span>  <span class="comment">// the first auto-save timeout occurs.</span></div>
|
||||
<div class="line"><a name="l00575"></a><span class="lineno"> 575</span>  <span class="keywordflow">if</span> (firstSave && credits >= RNG_MAX_CREDITS) {</div>
|
||||
<div class="line"><a name="l00576"></a><span class="lineno"> 576</span>  firstSave = 0;</div>
|
||||
<div class="line"><a name="l00577"></a><span class="lineno"> 577</span>  <a class="code" href="classRNGClass.html#a139584fb249148e2058d1d645d090db7">save</a>();</div>
|
||||
<div class="line"><a name="l00578"></a><span class="lineno"> 578</span>  }</div>
|
||||
<div class="line"><a name="l00579"></a><span class="lineno"> 579</span> }</div>
|
||||
<div class="line"><a name="l00580"></a><span class="lineno"> 580</span> </div>
|
||||
<div class="line"><a name="l00607"></a><span class="lineno"><a class="line" href="classRNGClass.html#a139584fb249148e2058d1d645d090db7"> 607</a></span> <span class="keywordtype">void</span> <a class="code" href="classRNGClass.html#a139584fb249148e2058d1d645d090db7">RNGClass::save</a>()</div>
|
||||
<div class="line"><a name="l00608"></a><span class="lineno"> 608</span> {</div>
|
||||
<div class="line"><a name="l00609"></a><span class="lineno"> 609</span>  <span class="comment">// Generate random data from the current state and save</span></div>
|
||||
<div class="line"><a name="l00610"></a><span class="lineno"> 610</span>  <span class="comment">// that as the seed. Then force a rekey.</span></div>
|
||||
<div class="line"><a name="l00611"></a><span class="lineno"> 611</span>  ++(block[12]);</div>
|
||||
<div class="line"><a name="l00612"></a><span class="lineno"> 612</span>  <a class="code" href="classChaCha.html#a41ac3262e52ff49dcd916d0b3b2e2038">ChaCha::hashCore</a>(stream, block, RNG_ROUNDS);</div>
|
||||
<div class="line"><a name="l00613"></a><span class="lineno"> 613</span> <span class="preprocessor">#if defined(RNG_EEPROM)</span></div>
|
||||
<div class="line"><a name="l00614"></a><span class="lineno"> 614</span> <span class="preprocessor"></span> eeprom_write_block(stream, (<span class="keywordtype">void</span> *)(address + 1), 48);</div>
|
||||
<div class="line"><a name="l00615"></a><span class="lineno"> 615</span>  eeprom_update_byte((uint8_t *)address, <span class="charliteral">'S'</span>);</div>
|
||||
<div class="line"><a name="l00616"></a><span class="lineno"> 616</span> <span class="preprocessor">#elif defined(RNG_DUE_TRNG)</span></div>
|
||||
<div class="line"><a name="l00617"></a><span class="lineno"> 617</span> <span class="preprocessor"></span> <span class="keywordtype">unsigned</span> posn;</div>
|
||||
<div class="line"><a name="l00618"></a><span class="lineno"> 618</span>  ((uint32_t *)(RNG_SEED_ADDR))[0] = <span class="charliteral">'S'</span>;</div>
|
||||
<div class="line"><a name="l00619"></a><span class="lineno"> 619</span>  <span class="keywordflow">for</span> (posn = 0; posn < 12; ++posn)</div>
|
||||
<div class="line"><a name="l00620"></a><span class="lineno"> 620</span>  ((uint32_t *)(RNG_SEED_ADDR))[posn + 1] = stream[posn];</div>
|
||||
<div class="line"><a name="l00621"></a><span class="lineno"> 621</span>  <span class="keywordflow">for</span> (posn = 13; posn < (RNG_FLASH_PAGE_SIZE / 4); ++posn)</div>
|
||||
<div class="line"><a name="l00622"></a><span class="lineno"> 622</span>  ((uint32_t *)(RNG_SEED_ADDR))[posn + 13] = 0xFFFFFFFF;</div>
|
||||
<div class="line"><a name="l00623"></a><span class="lineno"> 623</span>  eraseAndWriteSeed();</div>
|
||||
<div class="line"><a name="l00624"></a><span class="lineno"> 624</span> <span class="preprocessor">#endif</span></div>
|
||||
<div class="line"><a name="l00625"></a><span class="lineno"> 625</span> <span class="preprocessor"></span> rekey();</div>
|
||||
<div class="line"><a name="l00626"></a><span class="lineno"> 626</span>  timer = millis();</div>
|
||||
<div class="line"><a name="l00627"></a><span class="lineno"> 627</span> }</div>
|
||||
<div class="line"><a name="l00628"></a><span class="lineno"> 628</span> </div>
|
||||
<div class="line"><a name="l00635"></a><span class="lineno"><a class="line" href="classRNGClass.html#a8cb91e39f0c4591de5bf98b1e2880b13"> 635</a></span> <span class="keywordtype">void</span> <a class="code" href="classRNGClass.html#a8cb91e39f0c4591de5bf98b1e2880b13">RNGClass::loop</a>()</div>
|
||||
<div class="line"><a name="l00636"></a><span class="lineno"> 636</span> {</div>
|
||||
<div class="line"><a name="l00637"></a><span class="lineno"> 637</span>  <span class="comment">// Stir in the entropy from all registered noise sources.</span></div>
|
||||
<div class="line"><a name="l00638"></a><span class="lineno"> 638</span>  <span class="keywordflow">for</span> (uint8_t posn = 0; posn < count; ++posn)</div>
|
||||
<div class="line"><a name="l00639"></a><span class="lineno"> 639</span>  noiseSources[posn]-><a class="code" href="classRNGClass.html#ad99535ea23ae2fec55bdebb8c24def02">stir</a>();</div>
|
||||
<div class="line"><a name="l00640"></a><span class="lineno"> 640</span> </div>
|
||||
<div class="line"><a name="l00641"></a><span class="lineno"> 641</span> <span class="preprocessor">#if defined(RNG_DUE_TRNG)</span></div>
|
||||
<div class="line"><a name="l00642"></a><span class="lineno"> 642</span> <span class="preprocessor"></span> <span class="comment">// If there is data available from the Arudino Due's TRNG, then XOR</span></div>
|
||||
<div class="line"><a name="l00643"></a><span class="lineno"> 643</span>  <span class="comment">// it with the state block and increase the entropy credit. We don't</span></div>
|
||||
<div class="line"><a name="l00644"></a><span class="lineno"> 644</span>  <span class="comment">// call stir() yet because that will seriously slow down the system</span></div>
|
||||
<div class="line"><a name="l00645"></a><span class="lineno"> 645</span>  <span class="comment">// given how fast the TRNG is. Instead we save up the XOR'ed TRNG</span></div>
|
||||
<div class="line"><a name="l00646"></a><span class="lineno"> 646</span>  <span class="comment">// data until the next rand() call and then hash it to generate the</span></div>
|
||||
<div class="line"><a name="l00647"></a><span class="lineno"> 647</span>  <span class="comment">// desired output.</span></div>
|
||||
<div class="line"><a name="l00648"></a><span class="lineno"> 648</span>  <span class="comment">//</span></div>
|
||||
<div class="line"><a name="l00649"></a><span class="lineno"> 649</span>  <span class="comment">// The CPU documentation claims that the TRNG output is very good so</span></div>
|
||||
<div class="line"><a name="l00650"></a><span class="lineno"> 650</span>  <span class="comment">// this should only make the pool more and more random as time goes on.</span></div>
|
||||
<div class="line"><a name="l00651"></a><span class="lineno"> 651</span>  <span class="comment">// However there is a risk that the CPU manufacturer was pressured by</span></div>
|
||||
<div class="line"><a name="l00652"></a><span class="lineno"> 652</span>  <span class="comment">// government or intelligence agencies to insert a back door that</span></div>
|
||||
<div class="line"><a name="l00653"></a><span class="lineno"> 653</span>  <span class="comment">// generates predictable output. Or the manufacturer was overly</span></div>
|
||||
<div class="line"><a name="l00654"></a><span class="lineno"> 654</span>  <span class="comment">// optimistic about their TRNG design and it is actually flawed in a</span></div>
|
||||
<div class="line"><a name="l00655"></a><span class="lineno"> 655</span>  <span class="comment">// way they don't realise.</span></div>
|
||||
<div class="line"><a name="l00656"></a><span class="lineno"> 656</span>  <span class="comment">//</span></div>
|
||||
<div class="line"><a name="l00657"></a><span class="lineno"> 657</span>  <span class="comment">// If you are concerned about such threats, then make sure to mix in</span></div>
|
||||
<div class="line"><a name="l00658"></a><span class="lineno"> 658</span>  <span class="comment">// data from other noise sources. By hashing together the TRNG with</span></div>
|
||||
<div class="line"><a name="l00659"></a><span class="lineno"> 659</span>  <span class="comment">// the other noise data, rand() should produce unpredictable data even</span></div>
|
||||
<div class="line"><a name="l00660"></a><span class="lineno"> 660</span>  <span class="comment">// if one of the sources is actually predictable.</span></div>
|
||||
<div class="line"><a name="l00661"></a><span class="lineno"> 661</span>  <span class="keywordflow">if</span> ((REG_TRNG_ISR & TRNG_ISR_DATRDY) != 0) {</div>
|
||||
<div class="line"><a name="l00662"></a><span class="lineno"> 662</span>  block[4 + trngPosn] ^= REG_TRNG_ODATA;</div>
|
||||
<div class="line"><a name="l00663"></a><span class="lineno"> 663</span>  <span class="keywordflow">if</span> (++trngPosn >= 12)</div>
|
||||
<div class="line"><a name="l00664"></a><span class="lineno"> 664</span>  trngPosn = 0;</div>
|
||||
<div class="line"><a name="l00665"></a><span class="lineno"> 665</span>  <span class="keywordflow">if</span> (credits < RNG_MAX_CREDITS) {</div>
|
||||
<div class="line"><a name="l00666"></a><span class="lineno"> 666</span>  <span class="comment">// Credit 1 bit of entropy for the word. The TRNG should be</span></div>
|
||||
<div class="line"><a name="l00667"></a><span class="lineno"> 667</span>  <span class="comment">// better than this but it is so fast that we want to collect</span></div>
|
||||
<div class="line"><a name="l00668"></a><span class="lineno"> 668</span>  <span class="comment">// up more data before passing it to the application.</span></div>
|
||||
<div class="line"><a name="l00669"></a><span class="lineno"> 669</span>  ++credits;</div>
|
||||
<div class="line"><a name="l00670"></a><span class="lineno"> 670</span>  }</div>
|
||||
<div class="line"><a name="l00671"></a><span class="lineno"> 671</span>  }</div>
|
||||
<div class="line"><a name="l00672"></a><span class="lineno"> 672</span> <span class="preprocessor">#endif</span></div>
|
||||
<div class="line"><a name="l00673"></a><span class="lineno"> 673</span> <span class="preprocessor"></span></div>
|
||||
<div class="line"><a name="l00674"></a><span class="lineno"> 674</span>  <span class="comment">// Save the seed if the auto-save timer has expired.</span></div>
|
||||
<div class="line"><a name="l00675"></a><span class="lineno"> 675</span>  <span class="keywordflow">if</span> ((millis() - timer) >= timeout)</div>
|
||||
<div class="line"><a name="l00676"></a><span class="lineno"> 676</span>  <a class="code" href="classRNGClass.html#a139584fb249148e2058d1d645d090db7">save</a>();</div>
|
||||
<div class="line"><a name="l00677"></a><span class="lineno"> 677</span> }</div>
|
||||
<div class="line"><a name="l00678"></a><span class="lineno"> 678</span> </div>
|
||||
<div class="line"><a name="l00698"></a><span class="lineno"><a class="line" href="classRNGClass.html#a9901367d86f2303a59bbc12fe91cad00"> 698</a></span> <span class="keywordtype">void</span> <a class="code" href="classRNGClass.html#a9901367d86f2303a59bbc12fe91cad00">RNGClass::destroy</a>()</div>
|
||||
<div class="line"><a name="l00699"></a><span class="lineno"> 699</span> {</div>
|
||||
<div class="line"><a name="l00700"></a><span class="lineno"> 700</span>  clean(block);</div>
|
||||
<div class="line"><a name="l00701"></a><span class="lineno"> 701</span>  clean(stream);</div>
|
||||
<div class="line"><a name="l00702"></a><span class="lineno"> 702</span> <span class="preprocessor">#if defined(RNG_EEPROM)</span></div>
|
||||
<div class="line"><a name="l00703"></a><span class="lineno"> 703</span> <span class="preprocessor"></span> <span class="keywordflow">for</span> (<span class="keywordtype">int</span> posn = 0; posn < <a class="code" href="classRNGClass.html#ae3a013bfc73795fd26ee36e70d89f4c2">SEED_SIZE</a>; ++posn)</div>
|
||||
<div class="line"><a name="l00704"></a><span class="lineno"> 704</span>  eeprom_write_byte((uint8_t *)(address + posn), 0xFF);</div>
|
||||
<div class="line"><a name="l00705"></a><span class="lineno"> 705</span> <span class="preprocessor">#elif defined(RNG_DUE_TRNG)</span></div>
|
||||
<div class="line"><a name="l00706"></a><span class="lineno"> 706</span> <span class="preprocessor"></span> <span class="keywordflow">for</span> (<span class="keywordtype">unsigned</span> posn = 0; posn < (RNG_FLASH_PAGE_SIZE / 4); ++posn)</div>
|
||||
<div class="line"><a name="l00707"></a><span class="lineno"> 707</span>  ((uint32_t *)(RNG_SEED_ADDR))[posn] = 0xFFFFFFFF;</div>
|
||||
<div class="line"><a name="l00708"></a><span class="lineno"> 708</span>  eraseAndWriteSeed();</div>
|
||||
<div class="line"><a name="l00709"></a><span class="lineno"> 709</span> <span class="preprocessor">#endif</span></div>
|
||||
<div class="line"><a name="l00710"></a><span class="lineno"> 710</span> <span class="preprocessor"></span>}</div>
|
||||
<div class="line"><a name="l00711"></a><span class="lineno"> 711</span> </div>
|
||||
<div class="line"><a name="l00715"></a><span class="lineno"> 715</span> <span class="keywordtype">void</span> RNGClass::rekey()</div>
|
||||
<div class="line"><a name="l00459"></a><span class="lineno"><a class="line" href="classRNGClass.html#aacf23b192b0e4cc8726d9abe05f5a9db"> 459</a></span> <span class="keywordtype">void</span> <a class="code" href="classRNGClass.html#aacf23b192b0e4cc8726d9abe05f5a9db">RNGClass::addNoiseSource</a>(<a class="code" href="classNoiseSource.html">NoiseSource</a> &source)</div>
|
||||
<div class="line"><a name="l00460"></a><span class="lineno"> 460</span> {</div>
|
||||
<div class="line"><a name="l00461"></a><span class="lineno"> 461</span> <span class="preprocessor"> #define MAX_NOISE_SOURCES (sizeof(noiseSources) / sizeof(noiseSources[0]))</span></div>
|
||||
<div class="line"><a name="l00462"></a><span class="lineno"> 462</span> <span class="preprocessor"></span> <span class="keywordflow">if</span> (count < MAX_NOISE_SOURCES) {</div>
|
||||
<div class="line"><a name="l00463"></a><span class="lineno"> 463</span>  noiseSources[count++] = &source;</div>
|
||||
<div class="line"><a name="l00464"></a><span class="lineno"> 464</span>  source.<a class="code" href="classNoiseSource.html#a48d0efabd71ff6e557a0898be79c49ba">added</a>();</div>
|
||||
<div class="line"><a name="l00465"></a><span class="lineno"> 465</span>  }</div>
|
||||
<div class="line"><a name="l00466"></a><span class="lineno"> 466</span> }</div>
|
||||
<div class="line"><a name="l00467"></a><span class="lineno"> 467</span> </div>
|
||||
<div class="line"><a name="l00484"></a><span class="lineno"><a class="line" href="classRNGClass.html#a5848e87a5f2f0302c88b0377f0e3366d"> 484</a></span> <span class="keywordtype">void</span> <a class="code" href="classRNGClass.html#a5848e87a5f2f0302c88b0377f0e3366d">RNGClass::setAutoSaveTime</a>(uint16_t minutes)</div>
|
||||
<div class="line"><a name="l00485"></a><span class="lineno"> 485</span> {</div>
|
||||
<div class="line"><a name="l00486"></a><span class="lineno"> 486</span>  <span class="keywordflow">if</span> (!minutes)</div>
|
||||
<div class="line"><a name="l00487"></a><span class="lineno"> 487</span>  minutes = 1; <span class="comment">// Just in case.</span></div>
|
||||
<div class="line"><a name="l00488"></a><span class="lineno"> 488</span>  timeout = ((uint32_t)minutes) * 60000U;</div>
|
||||
<div class="line"><a name="l00489"></a><span class="lineno"> 489</span> }</div>
|
||||
<div class="line"><a name="l00490"></a><span class="lineno"> 490</span> </div>
|
||||
<div class="line"><a name="l00508"></a><span class="lineno"><a class="line" href="classRNGClass.html#a418a833cf18198fd7e5d6dbd78c99c29"> 508</a></span> <span class="keywordtype">void</span> <a class="code" href="classRNGClass.html#a418a833cf18198fd7e5d6dbd78c99c29">RNGClass::rand</a>(uint8_t *data, <span class="keywordtype">size_t</span> len)</div>
|
||||
<div class="line"><a name="l00509"></a><span class="lineno"> 509</span> {</div>
|
||||
<div class="line"><a name="l00510"></a><span class="lineno"> 510</span>  <span class="comment">// Decrease the amount of entropy in the pool.</span></div>
|
||||
<div class="line"><a name="l00511"></a><span class="lineno"> 511</span>  <span class="keywordflow">if</span> (len > (credits / 8))</div>
|
||||
<div class="line"><a name="l00512"></a><span class="lineno"> 512</span>  credits = 0;</div>
|
||||
<div class="line"><a name="l00513"></a><span class="lineno"> 513</span>  <span class="keywordflow">else</span></div>
|
||||
<div class="line"><a name="l00514"></a><span class="lineno"> 514</span>  credits -= len * 8;</div>
|
||||
<div class="line"><a name="l00515"></a><span class="lineno"> 515</span> </div>
|
||||
<div class="line"><a name="l00516"></a><span class="lineno"> 516</span>  <span class="comment">// Generate the random data.</span></div>
|
||||
<div class="line"><a name="l00517"></a><span class="lineno"> 517</span>  uint8_t count = 0;</div>
|
||||
<div class="line"><a name="l00518"></a><span class="lineno"> 518</span>  <span class="keywordflow">while</span> (len > 0) {</div>
|
||||
<div class="line"><a name="l00519"></a><span class="lineno"> 519</span>  <span class="comment">// Force a rekey if we have generated too many blocks in this request.</span></div>
|
||||
<div class="line"><a name="l00520"></a><span class="lineno"> 520</span>  <span class="keywordflow">if</span> (count >= RNG_REKEY_BLOCKS) {</div>
|
||||
<div class="line"><a name="l00521"></a><span class="lineno"> 521</span>  rekey();</div>
|
||||
<div class="line"><a name="l00522"></a><span class="lineno"> 522</span>  count = 1;</div>
|
||||
<div class="line"><a name="l00523"></a><span class="lineno"> 523</span>  } <span class="keywordflow">else</span> {</div>
|
||||
<div class="line"><a name="l00524"></a><span class="lineno"> 524</span>  ++count;</div>
|
||||
<div class="line"><a name="l00525"></a><span class="lineno"> 525</span>  }</div>
|
||||
<div class="line"><a name="l00526"></a><span class="lineno"> 526</span> </div>
|
||||
<div class="line"><a name="l00527"></a><span class="lineno"> 527</span>  <span class="comment">// Increment the low counter word and generate a new keystream block.</span></div>
|
||||
<div class="line"><a name="l00528"></a><span class="lineno"> 528</span>  ++(block[12]);</div>
|
||||
<div class="line"><a name="l00529"></a><span class="lineno"> 529</span>  <a class="code" href="classChaCha.html#a41ac3262e52ff49dcd916d0b3b2e2038">ChaCha::hashCore</a>(stream, block, RNG_ROUNDS);</div>
|
||||
<div class="line"><a name="l00530"></a><span class="lineno"> 530</span> </div>
|
||||
<div class="line"><a name="l00531"></a><span class="lineno"> 531</span>  <span class="comment">// Copy the data to the return buffer.</span></div>
|
||||
<div class="line"><a name="l00532"></a><span class="lineno"> 532</span>  <span class="keywordflow">if</span> (len < 64) {</div>
|
||||
<div class="line"><a name="l00533"></a><span class="lineno"> 533</span>  memcpy(data, stream, len);</div>
|
||||
<div class="line"><a name="l00534"></a><span class="lineno"> 534</span>  <span class="keywordflow">break</span>;</div>
|
||||
<div class="line"><a name="l00535"></a><span class="lineno"> 535</span>  } <span class="keywordflow">else</span> {</div>
|
||||
<div class="line"><a name="l00536"></a><span class="lineno"> 536</span>  memcpy(data, stream, 64);</div>
|
||||
<div class="line"><a name="l00537"></a><span class="lineno"> 537</span>  data += 64;</div>
|
||||
<div class="line"><a name="l00538"></a><span class="lineno"> 538</span>  len -= 64;</div>
|
||||
<div class="line"><a name="l00539"></a><span class="lineno"> 539</span>  }</div>
|
||||
<div class="line"><a name="l00540"></a><span class="lineno"> 540</span>  }</div>
|
||||
<div class="line"><a name="l00541"></a><span class="lineno"> 541</span> </div>
|
||||
<div class="line"><a name="l00542"></a><span class="lineno"> 542</span>  <span class="comment">// Force a rekey after every request.</span></div>
|
||||
<div class="line"><a name="l00543"></a><span class="lineno"> 543</span>  rekey();</div>
|
||||
<div class="line"><a name="l00544"></a><span class="lineno"> 544</span> }</div>
|
||||
<div class="line"><a name="l00545"></a><span class="lineno"> 545</span> </div>
|
||||
<div class="line"><a name="l00585"></a><span class="lineno"><a class="line" href="classRNGClass.html#a49e3231ba65a5e4b045bc90976e0a659"> 585</a></span> <span class="keywordtype">bool</span> <a class="code" href="classRNGClass.html#a49e3231ba65a5e4b045bc90976e0a659">RNGClass::available</a>(<span class="keywordtype">size_t</span> len)<span class="keyword"> const</span></div>
|
||||
<div class="line"><a name="l00586"></a><span class="lineno"> 586</span> <span class="keyword"></span>{</div>
|
||||
<div class="line"><a name="l00587"></a><span class="lineno"> 587</span>  <span class="keywordflow">if</span> (len >= (RNG_MAX_CREDITS / 8))</div>
|
||||
<div class="line"><a name="l00588"></a><span class="lineno"> 588</span>  <span class="keywordflow">return</span> credits >= RNG_MAX_CREDITS;</div>
|
||||
<div class="line"><a name="l00589"></a><span class="lineno"> 589</span>  <span class="keywordflow">else</span></div>
|
||||
<div class="line"><a name="l00590"></a><span class="lineno"> 590</span>  <span class="keywordflow">return</span> len <= (credits / 8);</div>
|
||||
<div class="line"><a name="l00591"></a><span class="lineno"> 591</span> }</div>
|
||||
<div class="line"><a name="l00592"></a><span class="lineno"> 592</span> </div>
|
||||
<div class="line"><a name="l00618"></a><span class="lineno"><a class="line" href="classRNGClass.html#ad99535ea23ae2fec55bdebb8c24def02"> 618</a></span> <span class="keywordtype">void</span> <a class="code" href="classRNGClass.html#ad99535ea23ae2fec55bdebb8c24def02">RNGClass::stir</a>(<span class="keyword">const</span> uint8_t *data, <span class="keywordtype">size_t</span> len, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> credit)</div>
|
||||
<div class="line"><a name="l00619"></a><span class="lineno"> 619</span> {</div>
|
||||
<div class="line"><a name="l00620"></a><span class="lineno"> 620</span>  <span class="comment">// Increase the entropy credit.</span></div>
|
||||
<div class="line"><a name="l00621"></a><span class="lineno"> 621</span>  <span class="keywordflow">if</span> ((credit / 8) >= len && len)</div>
|
||||
<div class="line"><a name="l00622"></a><span class="lineno"> 622</span>  credit = len * 8;</div>
|
||||
<div class="line"><a name="l00623"></a><span class="lineno"> 623</span>  <span class="keywordflow">if</span> ((RNG_MAX_CREDITS - credits) > credit)</div>
|
||||
<div class="line"><a name="l00624"></a><span class="lineno"> 624</span>  credits += credit;</div>
|
||||
<div class="line"><a name="l00625"></a><span class="lineno"> 625</span>  <span class="keywordflow">else</span></div>
|
||||
<div class="line"><a name="l00626"></a><span class="lineno"> 626</span>  credits = RNG_MAX_CREDITS;</div>
|
||||
<div class="line"><a name="l00627"></a><span class="lineno"> 627</span> </div>
|
||||
<div class="line"><a name="l00628"></a><span class="lineno"> 628</span>  <span class="comment">// Process the supplied input data.</span></div>
|
||||
<div class="line"><a name="l00629"></a><span class="lineno"> 629</span>  <span class="keywordflow">if</span> (len > 0) {</div>
|
||||
<div class="line"><a name="l00630"></a><span class="lineno"> 630</span>  <span class="comment">// XOR the data with the ChaCha input block in 48 byte</span></div>
|
||||
<div class="line"><a name="l00631"></a><span class="lineno"> 631</span>  <span class="comment">// chunks and rekey the ChaCha cipher for each chunk to mix</span></div>
|
||||
<div class="line"><a name="l00632"></a><span class="lineno"> 632</span>  <span class="comment">// the data in. This should scatter any "true entropy" in</span></div>
|
||||
<div class="line"><a name="l00633"></a><span class="lineno"> 633</span>  <span class="comment">// the input across the entire block.</span></div>
|
||||
<div class="line"><a name="l00634"></a><span class="lineno"> 634</span>  <span class="keywordflow">while</span> (len > 0) {</div>
|
||||
<div class="line"><a name="l00635"></a><span class="lineno"> 635</span>  <span class="keywordtype">size_t</span> templen = len;</div>
|
||||
<div class="line"><a name="l00636"></a><span class="lineno"> 636</span>  <span class="keywordflow">if</span> (templen > 48)</div>
|
||||
<div class="line"><a name="l00637"></a><span class="lineno"> 637</span>  templen = 48;</div>
|
||||
<div class="line"><a name="l00638"></a><span class="lineno"> 638</span>  uint8_t *output = ((uint8_t *)block) + 16;</div>
|
||||
<div class="line"><a name="l00639"></a><span class="lineno"> 639</span>  len -= templen;</div>
|
||||
<div class="line"><a name="l00640"></a><span class="lineno"> 640</span>  <span class="keywordflow">while</span> (templen > 0) {</div>
|
||||
<div class="line"><a name="l00641"></a><span class="lineno"> 641</span>  *output++ ^= *data++;</div>
|
||||
<div class="line"><a name="l00642"></a><span class="lineno"> 642</span>  --templen;</div>
|
||||
<div class="line"><a name="l00643"></a><span class="lineno"> 643</span>  }</div>
|
||||
<div class="line"><a name="l00644"></a><span class="lineno"> 644</span>  rekey();</div>
|
||||
<div class="line"><a name="l00645"></a><span class="lineno"> 645</span>  }</div>
|
||||
<div class="line"><a name="l00646"></a><span class="lineno"> 646</span>  } <span class="keywordflow">else</span> {</div>
|
||||
<div class="line"><a name="l00647"></a><span class="lineno"> 647</span>  <span class="comment">// There was no input data, so just force a rekey so we</span></div>
|
||||
<div class="line"><a name="l00648"></a><span class="lineno"> 648</span>  <span class="comment">// get some mixing of the state even without new data.</span></div>
|
||||
<div class="line"><a name="l00649"></a><span class="lineno"> 649</span>  rekey();</div>
|
||||
<div class="line"><a name="l00650"></a><span class="lineno"> 650</span>  }</div>
|
||||
<div class="line"><a name="l00651"></a><span class="lineno"> 651</span> </div>
|
||||
<div class="line"><a name="l00652"></a><span class="lineno"> 652</span>  <span class="comment">// Save if this is the first time we have reached max entropy.</span></div>
|
||||
<div class="line"><a name="l00653"></a><span class="lineno"> 653</span>  <span class="comment">// This provides some protection if the system is powered off before</span></div>
|
||||
<div class="line"><a name="l00654"></a><span class="lineno"> 654</span>  <span class="comment">// the first auto-save timeout occurs.</span></div>
|
||||
<div class="line"><a name="l00655"></a><span class="lineno"> 655</span>  <span class="keywordflow">if</span> (firstSave && credits >= RNG_MAX_CREDITS) {</div>
|
||||
<div class="line"><a name="l00656"></a><span class="lineno"> 656</span>  firstSave = 0;</div>
|
||||
<div class="line"><a name="l00657"></a><span class="lineno"> 657</span>  <a class="code" href="classRNGClass.html#a139584fb249148e2058d1d645d090db7">save</a>();</div>
|
||||
<div class="line"><a name="l00658"></a><span class="lineno"> 658</span>  }</div>
|
||||
<div class="line"><a name="l00659"></a><span class="lineno"> 659</span> }</div>
|
||||
<div class="line"><a name="l00660"></a><span class="lineno"> 660</span> </div>
|
||||
<div class="line"><a name="l00687"></a><span class="lineno"><a class="line" href="classRNGClass.html#a139584fb249148e2058d1d645d090db7"> 687</a></span> <span class="keywordtype">void</span> <a class="code" href="classRNGClass.html#a139584fb249148e2058d1d645d090db7">RNGClass::save</a>()</div>
|
||||
<div class="line"><a name="l00688"></a><span class="lineno"> 688</span> {</div>
|
||||
<div class="line"><a name="l00689"></a><span class="lineno"> 689</span>  <span class="comment">// Generate random data from the current state and save</span></div>
|
||||
<div class="line"><a name="l00690"></a><span class="lineno"> 690</span>  <span class="comment">// that as the seed. Then force a rekey.</span></div>
|
||||
<div class="line"><a name="l00691"></a><span class="lineno"> 691</span>  ++(block[12]);</div>
|
||||
<div class="line"><a name="l00692"></a><span class="lineno"> 692</span>  <a class="code" href="classChaCha.html#a41ac3262e52ff49dcd916d0b3b2e2038">ChaCha::hashCore</a>(stream, block, RNG_ROUNDS);</div>
|
||||
<div class="line"><a name="l00693"></a><span class="lineno"> 693</span> <span class="preprocessor">#if defined(RNG_EEPROM)</span></div>
|
||||
<div class="line"><a name="l00694"></a><span class="lineno"> 694</span> <span class="preprocessor"></span> eeprom_write_block(stream, (<span class="keywordtype">void</span> *)(address + 1), 48);</div>
|
||||
<div class="line"><a name="l00695"></a><span class="lineno"> 695</span>  eeprom_update_byte((uint8_t *)address, <span class="charliteral">'S'</span>);</div>
|
||||
<div class="line"><a name="l00696"></a><span class="lineno"> 696</span> <span class="preprocessor">#elif defined(RNG_DUE_TRNG)</span></div>
|
||||
<div class="line"><a name="l00697"></a><span class="lineno"> 697</span> <span class="preprocessor"></span> <span class="keywordtype">unsigned</span> posn;</div>
|
||||
<div class="line"><a name="l00698"></a><span class="lineno"> 698</span>  ((uint32_t *)(RNG_SEED_ADDR))[0] = <span class="charliteral">'S'</span>;</div>
|
||||
<div class="line"><a name="l00699"></a><span class="lineno"> 699</span>  <span class="keywordflow">for</span> (posn = 0; posn < 12; ++posn)</div>
|
||||
<div class="line"><a name="l00700"></a><span class="lineno"> 700</span>  ((uint32_t *)(RNG_SEED_ADDR))[posn + 1] = stream[posn];</div>
|
||||
<div class="line"><a name="l00701"></a><span class="lineno"> 701</span>  <span class="keywordflow">for</span> (posn = 13; posn < (RNG_FLASH_PAGE_SIZE / 4); ++posn)</div>
|
||||
<div class="line"><a name="l00702"></a><span class="lineno"> 702</span>  ((uint32_t *)(RNG_SEED_ADDR))[posn + 13] = 0xFFFFFFFF;</div>
|
||||
<div class="line"><a name="l00703"></a><span class="lineno"> 703</span>  eraseAndWriteSeed();</div>
|
||||
<div class="line"><a name="l00704"></a><span class="lineno"> 704</span> <span class="preprocessor">#endif</span></div>
|
||||
<div class="line"><a name="l00705"></a><span class="lineno"> 705</span> <span class="preprocessor"></span> rekey();</div>
|
||||
<div class="line"><a name="l00706"></a><span class="lineno"> 706</span>  timer = millis();</div>
|
||||
<div class="line"><a name="l00707"></a><span class="lineno"> 707</span> }</div>
|
||||
<div class="line"><a name="l00708"></a><span class="lineno"> 708</span> </div>
|
||||
<div class="line"><a name="l00715"></a><span class="lineno"><a class="line" href="classRNGClass.html#a8cb91e39f0c4591de5bf98b1e2880b13"> 715</a></span> <span class="keywordtype">void</span> <a class="code" href="classRNGClass.html#a8cb91e39f0c4591de5bf98b1e2880b13">RNGClass::loop</a>()</div>
|
||||
<div class="line"><a name="l00716"></a><span class="lineno"> 716</span> {</div>
|
||||
<div class="line"><a name="l00717"></a><span class="lineno"> 717</span>  <span class="comment">// Rekey the cipher for the next request by generating a new block.</span></div>
|
||||
<div class="line"><a name="l00718"></a><span class="lineno"> 718</span>  <span class="comment">// This is intended to make it difficult to wind the random number</span></div>
|
||||
<div class="line"><a name="l00719"></a><span class="lineno"> 719</span>  <span class="comment">// backwards if the state is captured later. The first 16 bytes of</span></div>
|
||||
<div class="line"><a name="l00720"></a><span class="lineno"> 720</span>  <span class="comment">// "block" remain set to "tagRNG".</span></div>
|
||||
<div class="line"><a name="l00721"></a><span class="lineno"> 721</span>  ++(block[12]);</div>
|
||||
<div class="line"><a name="l00722"></a><span class="lineno"> 722</span>  <a class="code" href="classChaCha.html#a41ac3262e52ff49dcd916d0b3b2e2038">ChaCha::hashCore</a>(stream, block, RNG_ROUNDS);</div>
|
||||
<div class="line"><a name="l00723"></a><span class="lineno"> 723</span>  memcpy(block + 4, stream, 48);</div>
|
||||
<div class="line"><a name="l00724"></a><span class="lineno"> 724</span> </div>
|
||||
<div class="line"><a name="l00725"></a><span class="lineno"> 725</span>  <span class="comment">// Permute the high word of the counter using the system microsecond</span></div>
|
||||
<div class="line"><a name="l00726"></a><span class="lineno"> 726</span>  <span class="comment">// counter to introduce a little bit of non-stir randomness for each</span></div>
|
||||
<div class="line"><a name="l00727"></a><span class="lineno"> 727</span>  <span class="comment">// request. Note: If random data is requested on a predictable schedule</span></div>
|
||||
<div class="line"><a name="l00728"></a><span class="lineno"> 728</span>  <span class="comment">// then this may not help very much. It is still necessary to stir in</span></div>
|
||||
<div class="line"><a name="l00729"></a><span class="lineno"> 729</span>  <span class="comment">// high quality entropy data on a regular basis using stir().</span></div>
|
||||
<div class="line"><a name="l00730"></a><span class="lineno"> 730</span>  block[13] ^= micros();</div>
|
||||
<div class="line"><a name="l00731"></a><span class="lineno"> 731</span> }</div>
|
||||
<div class="ttc" id="classRNGClass_html_a139584fb249148e2058d1d645d090db7"><div class="ttname"><a href="classRNGClass.html#a139584fb249148e2058d1d645d090db7">RNGClass::save</a></div><div class="ttdeci">void save()</div><div class="ttdoc">Saves the random seed to EEPROM. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00607">RNG.cpp:607</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_a418a833cf18198fd7e5d6dbd78c99c29"><div class="ttname"><a href="classRNGClass.html#a418a833cf18198fd7e5d6dbd78c99c29">RNGClass::rand</a></div><div class="ttdeci">void rand(uint8_t *data, size_t len)</div><div class="ttdoc">Generates random bytes into a caller-supplied buffer. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00428">RNG.cpp:428</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_a7f1aab3c324f8e8a424d683425e0fcf8"><div class="ttname"><a href="classRNGClass.html#a7f1aab3c324f8e8a424d683425e0fcf8">RNGClass::begin</a></div><div class="ttdeci">void begin(const char *tag, int eepromAddress)</div><div class="ttdoc">Initializes the random number generator. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00296">RNG.cpp:296</a></div></div>
|
||||
<div class="line"><a name="l00717"></a><span class="lineno"> 717</span>  <span class="comment">// Stir in the entropy from all registered noise sources.</span></div>
|
||||
<div class="line"><a name="l00718"></a><span class="lineno"> 718</span>  <span class="keywordflow">for</span> (uint8_t posn = 0; posn < count; ++posn)</div>
|
||||
<div class="line"><a name="l00719"></a><span class="lineno"> 719</span>  noiseSources[posn]-><a class="code" href="classRNGClass.html#ad99535ea23ae2fec55bdebb8c24def02">stir</a>();</div>
|
||||
<div class="line"><a name="l00720"></a><span class="lineno"> 720</span> </div>
|
||||
<div class="line"><a name="l00721"></a><span class="lineno"> 721</span> <span class="preprocessor">#if defined(RNG_DUE_TRNG)</span></div>
|
||||
<div class="line"><a name="l00722"></a><span class="lineno"> 722</span> <span class="preprocessor"></span> <span class="comment">// If there is data available from the Arudino Due's TRNG, then XOR</span></div>
|
||||
<div class="line"><a name="l00723"></a><span class="lineno"> 723</span>  <span class="comment">// it with the state block and increase the entropy credit. We don't</span></div>
|
||||
<div class="line"><a name="l00724"></a><span class="lineno"> 724</span>  <span class="comment">// call stir() yet because that will seriously slow down the system</span></div>
|
||||
<div class="line"><a name="l00725"></a><span class="lineno"> 725</span>  <span class="comment">// given how fast the TRNG is. Instead we save up the XOR'ed TRNG</span></div>
|
||||
<div class="line"><a name="l00726"></a><span class="lineno"> 726</span>  <span class="comment">// data until the next rand() call and then hash it to generate the</span></div>
|
||||
<div class="line"><a name="l00727"></a><span class="lineno"> 727</span>  <span class="comment">// desired output.</span></div>
|
||||
<div class="line"><a name="l00728"></a><span class="lineno"> 728</span>  <span class="comment">//</span></div>
|
||||
<div class="line"><a name="l00729"></a><span class="lineno"> 729</span>  <span class="comment">// The CPU documentation claims that the TRNG output is very good so</span></div>
|
||||
<div class="line"><a name="l00730"></a><span class="lineno"> 730</span>  <span class="comment">// this should only make the pool more and more random as time goes on.</span></div>
|
||||
<div class="line"><a name="l00731"></a><span class="lineno"> 731</span>  <span class="comment">// However there is a risk that the CPU manufacturer was pressured by</span></div>
|
||||
<div class="line"><a name="l00732"></a><span class="lineno"> 732</span>  <span class="comment">// government or intelligence agencies to insert a back door that</span></div>
|
||||
<div class="line"><a name="l00733"></a><span class="lineno"> 733</span>  <span class="comment">// generates predictable output. Or the manufacturer was overly</span></div>
|
||||
<div class="line"><a name="l00734"></a><span class="lineno"> 734</span>  <span class="comment">// optimistic about their TRNG design and it is actually flawed in a</span></div>
|
||||
<div class="line"><a name="l00735"></a><span class="lineno"> 735</span>  <span class="comment">// way they don't realise.</span></div>
|
||||
<div class="line"><a name="l00736"></a><span class="lineno"> 736</span>  <span class="comment">//</span></div>
|
||||
<div class="line"><a name="l00737"></a><span class="lineno"> 737</span>  <span class="comment">// If you are concerned about such threats, then make sure to mix in</span></div>
|
||||
<div class="line"><a name="l00738"></a><span class="lineno"> 738</span>  <span class="comment">// data from other noise sources. By hashing together the TRNG with</span></div>
|
||||
<div class="line"><a name="l00739"></a><span class="lineno"> 739</span>  <span class="comment">// the other noise data, rand() should produce unpredictable data even</span></div>
|
||||
<div class="line"><a name="l00740"></a><span class="lineno"> 740</span>  <span class="comment">// if one of the sources is actually predictable.</span></div>
|
||||
<div class="line"><a name="l00741"></a><span class="lineno"> 741</span>  <span class="keywordflow">if</span> ((REG_TRNG_ISR & TRNG_ISR_DATRDY) != 0) {</div>
|
||||
<div class="line"><a name="l00742"></a><span class="lineno"> 742</span>  block[4 + trngPosn] ^= REG_TRNG_ODATA;</div>
|
||||
<div class="line"><a name="l00743"></a><span class="lineno"> 743</span>  <span class="keywordflow">if</span> (++trngPosn >= 12)</div>
|
||||
<div class="line"><a name="l00744"></a><span class="lineno"> 744</span>  trngPosn = 0;</div>
|
||||
<div class="line"><a name="l00745"></a><span class="lineno"> 745</span>  <span class="keywordflow">if</span> (credits < RNG_MAX_CREDITS) {</div>
|
||||
<div class="line"><a name="l00746"></a><span class="lineno"> 746</span>  <span class="comment">// Credit 1 bit of entropy for the word. The TRNG should be</span></div>
|
||||
<div class="line"><a name="l00747"></a><span class="lineno"> 747</span>  <span class="comment">// better than this but it is so fast that we want to collect</span></div>
|
||||
<div class="line"><a name="l00748"></a><span class="lineno"> 748</span>  <span class="comment">// up more data before passing it to the application.</span></div>
|
||||
<div class="line"><a name="l00749"></a><span class="lineno"> 749</span>  ++credits;</div>
|
||||
<div class="line"><a name="l00750"></a><span class="lineno"> 750</span>  }</div>
|
||||
<div class="line"><a name="l00751"></a><span class="lineno"> 751</span>  }</div>
|
||||
<div class="line"><a name="l00752"></a><span class="lineno"> 752</span> <span class="preprocessor">#elif defined(RNG_WATCHDOG)</span></div>
|
||||
<div class="line"><a name="l00753"></a><span class="lineno"> 753</span> <span class="preprocessor"></span> <span class="comment">// Read the 32 bit buffer from the WDT interrupt.</span></div>
|
||||
<div class="line"><a name="l00754"></a><span class="lineno"> 754</span>  cli();</div>
|
||||
<div class="line"><a name="l00755"></a><span class="lineno"> 755</span>  <span class="keywordflow">if</span> (outBits >= 32) {</div>
|
||||
<div class="line"><a name="l00756"></a><span class="lineno"> 756</span>  uint32_t value = hash;</div>
|
||||
<div class="line"><a name="l00757"></a><span class="lineno"> 757</span>  hash = 0;</div>
|
||||
<div class="line"><a name="l00758"></a><span class="lineno"> 758</span>  outBits = 0;</div>
|
||||
<div class="line"><a name="l00759"></a><span class="lineno"> 759</span>  sei();</div>
|
||||
<div class="line"><a name="l00760"></a><span class="lineno"> 760</span> </div>
|
||||
<div class="line"><a name="l00761"></a><span class="lineno"> 761</span>  <span class="comment">// Final steps of the Jenkin's one-at-a-time hash function.</span></div>
|
||||
<div class="line"><a name="l00762"></a><span class="lineno"> 762</span>  <span class="comment">// https://en.wikipedia.org/wiki/Jenkins_hash_function</span></div>
|
||||
<div class="line"><a name="l00763"></a><span class="lineno"> 763</span>  value += leftShift3(value);</div>
|
||||
<div class="line"><a name="l00764"></a><span class="lineno"> 764</span>  value ^= rightShift11(value);</div>
|
||||
<div class="line"><a name="l00765"></a><span class="lineno"> 765</span>  value += leftShift15(value);</div>
|
||||
<div class="line"><a name="l00766"></a><span class="lineno"> 766</span> </div>
|
||||
<div class="line"><a name="l00767"></a><span class="lineno"> 767</span>  <span class="comment">// XOR the word with the state. Stir once we accumulate 48 bytes,</span></div>
|
||||
<div class="line"><a name="l00768"></a><span class="lineno"> 768</span>  <span class="comment">// which happens about once every 6.4 seconds.</span></div>
|
||||
<div class="line"><a name="l00769"></a><span class="lineno"> 769</span>  block[4 + trngPosn] ^= value;</div>
|
||||
<div class="line"><a name="l00770"></a><span class="lineno"> 770</span>  <span class="keywordflow">if</span> (++trngPosn >= 12) {</div>
|
||||
<div class="line"><a name="l00771"></a><span class="lineno"> 771</span>  trngPosn = 0;</div>
|
||||
<div class="line"><a name="l00772"></a><span class="lineno"> 772</span> </div>
|
||||
<div class="line"><a name="l00773"></a><span class="lineno"> 773</span>  <span class="comment">// Credit 1 bit of entropy for each byte of input. It can take</span></div>
|
||||
<div class="line"><a name="l00774"></a><span class="lineno"> 774</span>  <span class="comment">// between 30 and 40 seconds to accumulate 256 bits of credit.</span></div>
|
||||
<div class="line"><a name="l00775"></a><span class="lineno"> 775</span>  <a class="code" href="classRNGClass.html#ad99535ea23ae2fec55bdebb8c24def02">stir</a>(0, 0, 48);</div>
|
||||
<div class="line"><a name="l00776"></a><span class="lineno"> 776</span>  }</div>
|
||||
<div class="line"><a name="l00777"></a><span class="lineno"> 777</span>  } <span class="keywordflow">else</span> {</div>
|
||||
<div class="line"><a name="l00778"></a><span class="lineno"> 778</span>  sei();</div>
|
||||
<div class="line"><a name="l00779"></a><span class="lineno"> 779</span>  }</div>
|
||||
<div class="line"><a name="l00780"></a><span class="lineno"> 780</span> <span class="preprocessor">#endif</span></div>
|
||||
<div class="line"><a name="l00781"></a><span class="lineno"> 781</span> <span class="preprocessor"></span></div>
|
||||
<div class="line"><a name="l00782"></a><span class="lineno"> 782</span>  <span class="comment">// Save the seed if the auto-save timer has expired.</span></div>
|
||||
<div class="line"><a name="l00783"></a><span class="lineno"> 783</span>  <span class="keywordflow">if</span> ((millis() - timer) >= timeout)</div>
|
||||
<div class="line"><a name="l00784"></a><span class="lineno"> 784</span>  <a class="code" href="classRNGClass.html#a139584fb249148e2058d1d645d090db7">save</a>();</div>
|
||||
<div class="line"><a name="l00785"></a><span class="lineno"> 785</span> }</div>
|
||||
<div class="line"><a name="l00786"></a><span class="lineno"> 786</span> </div>
|
||||
<div class="line"><a name="l00806"></a><span class="lineno"><a class="line" href="classRNGClass.html#a9901367d86f2303a59bbc12fe91cad00"> 806</a></span> <span class="keywordtype">void</span> <a class="code" href="classRNGClass.html#a9901367d86f2303a59bbc12fe91cad00">RNGClass::destroy</a>()</div>
|
||||
<div class="line"><a name="l00807"></a><span class="lineno"> 807</span> {</div>
|
||||
<div class="line"><a name="l00808"></a><span class="lineno"> 808</span>  clean(block);</div>
|
||||
<div class="line"><a name="l00809"></a><span class="lineno"> 809</span>  clean(stream);</div>
|
||||
<div class="line"><a name="l00810"></a><span class="lineno"> 810</span> <span class="preprocessor">#if defined(RNG_EEPROM)</span></div>
|
||||
<div class="line"><a name="l00811"></a><span class="lineno"> 811</span> <span class="preprocessor"></span> <span class="keywordflow">for</span> (<span class="keywordtype">int</span> posn = 0; posn < <a class="code" href="classRNGClass.html#ae3a013bfc73795fd26ee36e70d89f4c2">SEED_SIZE</a>; ++posn)</div>
|
||||
<div class="line"><a name="l00812"></a><span class="lineno"> 812</span>  eeprom_write_byte((uint8_t *)(address + posn), 0xFF);</div>
|
||||
<div class="line"><a name="l00813"></a><span class="lineno"> 813</span> <span class="preprocessor">#elif defined(RNG_DUE_TRNG)</span></div>
|
||||
<div class="line"><a name="l00814"></a><span class="lineno"> 814</span> <span class="preprocessor"></span> <span class="keywordflow">for</span> (<span class="keywordtype">unsigned</span> posn = 0; posn < (RNG_FLASH_PAGE_SIZE / 4); ++posn)</div>
|
||||
<div class="line"><a name="l00815"></a><span class="lineno"> 815</span>  ((uint32_t *)(RNG_SEED_ADDR))[posn] = 0xFFFFFFFF;</div>
|
||||
<div class="line"><a name="l00816"></a><span class="lineno"> 816</span>  eraseAndWriteSeed();</div>
|
||||
<div class="line"><a name="l00817"></a><span class="lineno"> 817</span> <span class="preprocessor">#endif</span></div>
|
||||
<div class="line"><a name="l00818"></a><span class="lineno"> 818</span> <span class="preprocessor"></span>}</div>
|
||||
<div class="line"><a name="l00819"></a><span class="lineno"> 819</span> </div>
|
||||
<div class="line"><a name="l00823"></a><span class="lineno"> 823</span> <span class="keywordtype">void</span> RNGClass::rekey()</div>
|
||||
<div class="line"><a name="l00824"></a><span class="lineno"> 824</span> {</div>
|
||||
<div class="line"><a name="l00825"></a><span class="lineno"> 825</span>  <span class="comment">// Rekey the cipher for the next request by generating a new block.</span></div>
|
||||
<div class="line"><a name="l00826"></a><span class="lineno"> 826</span>  <span class="comment">// This is intended to make it difficult to wind the random number</span></div>
|
||||
<div class="line"><a name="l00827"></a><span class="lineno"> 827</span>  <span class="comment">// backwards if the state is captured later. The first 16 bytes of</span></div>
|
||||
<div class="line"><a name="l00828"></a><span class="lineno"> 828</span>  <span class="comment">// "block" remain set to "tagRNG".</span></div>
|
||||
<div class="line"><a name="l00829"></a><span class="lineno"> 829</span>  ++(block[12]);</div>
|
||||
<div class="line"><a name="l00830"></a><span class="lineno"> 830</span>  <a class="code" href="classChaCha.html#a41ac3262e52ff49dcd916d0b3b2e2038">ChaCha::hashCore</a>(stream, block, RNG_ROUNDS);</div>
|
||||
<div class="line"><a name="l00831"></a><span class="lineno"> 831</span>  memcpy(block + 4, stream, 48);</div>
|
||||
<div class="line"><a name="l00832"></a><span class="lineno"> 832</span> </div>
|
||||
<div class="line"><a name="l00833"></a><span class="lineno"> 833</span>  <span class="comment">// Permute the high word of the counter using the system microsecond</span></div>
|
||||
<div class="line"><a name="l00834"></a><span class="lineno"> 834</span>  <span class="comment">// counter to introduce a little bit of non-stir randomness for each</span></div>
|
||||
<div class="line"><a name="l00835"></a><span class="lineno"> 835</span>  <span class="comment">// request. Note: If random data is requested on a predictable schedule</span></div>
|
||||
<div class="line"><a name="l00836"></a><span class="lineno"> 836</span>  <span class="comment">// then this may not help very much. It is still necessary to stir in</span></div>
|
||||
<div class="line"><a name="l00837"></a><span class="lineno"> 837</span>  <span class="comment">// high quality entropy data on a regular basis using stir().</span></div>
|
||||
<div class="line"><a name="l00838"></a><span class="lineno"> 838</span>  block[13] ^= micros();</div>
|
||||
<div class="line"><a name="l00839"></a><span class="lineno"> 839</span> }</div>
|
||||
<div class="ttc" id="classRNGClass_html_a139584fb249148e2058d1d645d090db7"><div class="ttname"><a href="classRNGClass.html#a139584fb249148e2058d1d645d090db7">RNGClass::save</a></div><div class="ttdeci">void save()</div><div class="ttdoc">Saves the random seed to EEPROM. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00687">RNG.cpp:687</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_a418a833cf18198fd7e5d6dbd78c99c29"><div class="ttname"><a href="classRNGClass.html#a418a833cf18198fd7e5d6dbd78c99c29">RNGClass::rand</a></div><div class="ttdeci">void rand(uint8_t *data, size_t len)</div><div class="ttdoc">Generates random bytes into a caller-supplied buffer. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00508">RNG.cpp:508</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_a7f1aab3c324f8e8a424d683425e0fcf8"><div class="ttname"><a href="classRNGClass.html#a7f1aab3c324f8e8a424d683425e0fcf8">RNGClass::begin</a></div><div class="ttdeci">void begin(const char *tag, int eepromAddress)</div><div class="ttdoc">Initializes the random number generator. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00359">RNG.cpp:359</a></div></div>
|
||||
<div class="ttc" id="classNoiseSource_html"><div class="ttname"><a href="classNoiseSource.html">NoiseSource</a></div><div class="ttdoc">Abstract base class for random noise sources. </div><div class="ttdef"><b>Definition:</b> <a href="NoiseSource_8h_source.html#l00029">NoiseSource.h:29</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_aef3ee2fb14a39caf650dc90a0226dd31"><div class="ttname"><a href="classRNGClass.html#aef3ee2fb14a39caf650dc90a0226dd31">RNGClass::~RNGClass</a></div><div class="ttdeci">~RNGClass()</div><div class="ttdoc">Destroys this random number generator instance. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00196">RNG.cpp:196</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_aef3ee2fb14a39caf650dc90a0226dd31"><div class="ttname"><a href="classRNGClass.html#aef3ee2fb14a39caf650dc90a0226dd31">RNGClass::~RNGClass</a></div><div class="ttdeci">~RNGClass()</div><div class="ttdoc">Destroys this random number generator instance. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00244">RNG.cpp:244</a></div></div>
|
||||
<div class="ttc" id="classNoiseSource_html_a48d0efabd71ff6e557a0898be79c49ba"><div class="ttname"><a href="classNoiseSource.html#a48d0efabd71ff6e557a0898be79c49ba">NoiseSource::added</a></div><div class="ttdeci">virtual void added()</div><div class="ttdoc">Called when the noise source is added to RNG with RNG.addNoiseSource(). </div><div class="ttdef"><b>Definition:</b> <a href="NoiseSource_8cpp_source.html#l00095">NoiseSource.cpp:95</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_aacf23b192b0e4cc8726d9abe05f5a9db"><div class="ttname"><a href="classRNGClass.html#aacf23b192b0e4cc8726d9abe05f5a9db">RNGClass::addNoiseSource</a></div><div class="ttdeci">void addNoiseSource(NoiseSource &source)</div><div class="ttdoc">Adds a noise source to the random number generator. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00379">RNG.cpp:379</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_acbcf327242f51ae2d9209aeaa45e30e9"><div class="ttname"><a href="classRNGClass.html#acbcf327242f51ae2d9209aeaa45e30e9">RNGClass::RNGClass</a></div><div class="ttdeci">RNGClass()</div><div class="ttdoc">Constructs a new random number generator instance. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00182">RNG.cpp:182</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_a9901367d86f2303a59bbc12fe91cad00"><div class="ttname"><a href="classRNGClass.html#a9901367d86f2303a59bbc12fe91cad00">RNGClass::destroy</a></div><div class="ttdeci">void destroy()</div><div class="ttdoc">Destroys the data in the random number pool and the saved seed in EEPROM. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00698">RNG.cpp:698</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_a49e3231ba65a5e4b045bc90976e0a659"><div class="ttname"><a href="classRNGClass.html#a49e3231ba65a5e4b045bc90976e0a659">RNGClass::available</a></div><div class="ttdeci">bool available(size_t len) const </div><div class="ttdoc">Determine if there is sufficient entropy available for a specific request size. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00505">RNG.cpp:505</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_a8cb91e39f0c4591de5bf98b1e2880b13"><div class="ttname"><a href="classRNGClass.html#a8cb91e39f0c4591de5bf98b1e2880b13">RNGClass::loop</a></div><div class="ttdeci">void loop()</div><div class="ttdoc">Run periodic housekeeping tasks on the random number generator. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00635">RNG.cpp:635</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_aacf23b192b0e4cc8726d9abe05f5a9db"><div class="ttname"><a href="classRNGClass.html#aacf23b192b0e4cc8726d9abe05f5a9db">RNGClass::addNoiseSource</a></div><div class="ttdeci">void addNoiseSource(NoiseSource &source)</div><div class="ttdoc">Adds a noise source to the random number generator. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00459">RNG.cpp:459</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_acbcf327242f51ae2d9209aeaa45e30e9"><div class="ttname"><a href="classRNGClass.html#acbcf327242f51ae2d9209aeaa45e30e9">RNGClass::RNGClass</a></div><div class="ttdeci">RNGClass()</div><div class="ttdoc">Constructs a new random number generator instance. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00230">RNG.cpp:230</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_a9901367d86f2303a59bbc12fe91cad00"><div class="ttname"><a href="classRNGClass.html#a9901367d86f2303a59bbc12fe91cad00">RNGClass::destroy</a></div><div class="ttdeci">void destroy()</div><div class="ttdoc">Destroys the data in the random number pool and the saved seed in EEPROM. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00806">RNG.cpp:806</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_a49e3231ba65a5e4b045bc90976e0a659"><div class="ttname"><a href="classRNGClass.html#a49e3231ba65a5e4b045bc90976e0a659">RNGClass::available</a></div><div class="ttdeci">bool available(size_t len) const </div><div class="ttdoc">Determine if there is sufficient entropy available for a specific request size. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00585">RNG.cpp:585</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_a8cb91e39f0c4591de5bf98b1e2880b13"><div class="ttname"><a href="classRNGClass.html#a8cb91e39f0c4591de5bf98b1e2880b13">RNGClass::loop</a></div><div class="ttdeci">void loop()</div><div class="ttdoc">Run periodic housekeeping tasks on the random number generator. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00715">RNG.cpp:715</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html"><div class="ttname"><a href="classRNGClass.html">RNGClass</a></div><div class="ttdoc">Pseudo random number generator suitable for cryptography. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8h_source.html#l00031">RNG.h:31</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_ae3a013bfc73795fd26ee36e70d89f4c2"><div class="ttname"><a href="classRNGClass.html#ae3a013bfc73795fd26ee36e70d89f4c2">RNGClass::SEED_SIZE</a></div><div class="ttdeci">static const int SEED_SIZE</div><div class="ttdoc">Size of a saved random number seed in EEPROM space. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8h_source.html#l00053">RNG.h:53</a></div></div>
|
||||
<div class="ttc" id="classChaCha_html_a41ac3262e52ff49dcd916d0b3b2e2038"><div class="ttname"><a href="classChaCha.html#a41ac3262e52ff49dcd916d0b3b2e2038">ChaCha::hashCore</a></div><div class="ttdeci">static void hashCore(uint32_t *output, const uint32_t *input, uint8_t rounds)</div><div class="ttdoc">Executes the ChaCha hash core on an input memory block. </div><div class="ttdef"><b>Definition:</b> <a href="ChaCha_8cpp_source.html#l00253">ChaCha.cpp:253</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_ad99535ea23ae2fec55bdebb8c24def02"><div class="ttname"><a href="classRNGClass.html#ad99535ea23ae2fec55bdebb8c24def02">RNGClass::stir</a></div><div class="ttdeci">void stir(const uint8_t *data, size_t len, unsigned int credit=0)</div><div class="ttdoc">Stirs additional entropy data into the random pool. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00538">RNG.cpp:538</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_a5848e87a5f2f0302c88b0377f0e3366d"><div class="ttname"><a href="classRNGClass.html#a5848e87a5f2f0302c88b0377f0e3366d">RNGClass::setAutoSaveTime</a></div><div class="ttdeci">void setAutoSaveTime(uint16_t minutes)</div><div class="ttdoc">Sets the amount of time between automatic seed saves. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00404">RNG.cpp:404</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_ad99535ea23ae2fec55bdebb8c24def02"><div class="ttname"><a href="classRNGClass.html#ad99535ea23ae2fec55bdebb8c24def02">RNGClass::stir</a></div><div class="ttdeci">void stir(const uint8_t *data, size_t len, unsigned int credit=0)</div><div class="ttdoc">Stirs additional entropy data into the random pool. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00618">RNG.cpp:618</a></div></div>
|
||||
<div class="ttc" id="classRNGClass_html_a5848e87a5f2f0302c88b0377f0e3366d"><div class="ttname"><a href="classRNGClass.html#a5848e87a5f2f0302c88b0377f0e3366d">RNGClass::setAutoSaveTime</a></div><div class="ttdeci">void setAutoSaveTime(uint16_t minutes)</div><div class="ttdoc">Sets the amount of time between automatic seed saves. </div><div class="ttdef"><b>Definition:</b> <a href="RNG_8cpp_source.html#l00484">RNG.cpp:484</a></div></div>
|
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