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C++

/*
* Copyright (C) 2015 Southern Storm Software, Pty Ltd.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#include "SHA256.h"
#include "Crypto.h"
#include "utility/RotateUtil.h"
#include "utility/EndianUtil.h"
#include "utility/ProgMemUtil.h"
#include <string.h>
/**
* \class SHA256 SHA256.h <SHA256.h>
* \brief SHA-256 hash algorithm.
*
* Reference: http://en.wikipedia.org/wiki/SHA-2
*
* \sa SHA512, SHA3_256, BLAKE2s
*/
/**
* \brief Constructs a SHA-256 hash object.
*/
SHA256::SHA256()
{
reset();
}
/**
* \brief Destroys this SHA-256 hash object after clearing
* sensitive information.
*/
SHA256::~SHA256()
{
clean(state);
}
size_t SHA256::hashSize() const
{
return 32;
}
size_t SHA256::blockSize() const
{
return 64;
}
void SHA256::reset()
{
state.h[0] = 0x6a09e667;
state.h[1] = 0xbb67ae85;
state.h[2] = 0x3c6ef372;
state.h[3] = 0xa54ff53a,
state.h[4] = 0x510e527f;
state.h[5] = 0x9b05688c;
state.h[6] = 0x1f83d9ab;
state.h[7] = 0x5be0cd19;
state.chunkSize = 0;
state.length = 0;
}
void SHA256::update(const void *data, size_t len)
{
// Update the total length (in bits, not bytes).
state.length += ((uint64_t)len) << 3;
// Break the input up into 512-bit chunks and process each in turn.
const uint8_t *d = (const uint8_t *)data;
while (len > 0) {
uint8_t size = 64 - state.chunkSize;
if (size > len)
size = len;
memcpy(((uint8_t *)state.w) + state.chunkSize, d, size);
state.chunkSize += size;
len -= size;
d += size;
if (state.chunkSize == 64) {
processChunk();
state.chunkSize = 0;
}
}
}
void SHA256::finalize(void *hash, size_t len)
{
// Pad the last chunk. We may need two padding chunks if there
// isn't enough room in the first for the padding and length.
uint8_t *wbytes = (uint8_t *)state.w;
if (state.chunkSize <= (64 - 9)) {
wbytes[state.chunkSize] = 0x80;
memset(wbytes + state.chunkSize + 1, 0x00, 64 - 8 - (state.chunkSize + 1));
state.w[14] = htobe32((uint32_t)(state.length >> 32));
state.w[15] = htobe32((uint32_t)state.length);
processChunk();
} else {
wbytes[state.chunkSize] = 0x80;
memset(wbytes + state.chunkSize + 1, 0x00, 64 - (state.chunkSize + 1));
processChunk();
memset(wbytes, 0x00, 64 - 8);
state.w[14] = htobe32((uint32_t)(state.length >> 32));
state.w[15] = htobe32((uint32_t)state.length);
processChunk();
}
// Convert the result into big endian and return it.
for (uint8_t posn = 0; posn < 8; ++posn)
state.w[posn] = htobe32(state.h[posn]);
// Copy the hash to the caller's return buffer.
if (len > 32)
len = 32;
memcpy(hash, state.w, len);
}
void SHA256::clear()
{
clean(state);
reset();
}
void SHA256::resetHMAC(const void *key, size_t keyLen)
{
formatHMACKey(state.w, key, keyLen, 0x36);
state.length += 64 * 8;
processChunk();
}
void SHA256::finalizeHMAC(const void *key, size_t keyLen, void *hash, size_t hashLen)
{
uint8_t temp[32];
finalize(temp, sizeof(temp));
formatHMACKey(state.w, key, keyLen, 0x5C);
state.length += 64 * 8;
processChunk();
update(temp, sizeof(temp));
finalize(hash, hashLen);
clean(temp);
}
/**
* \brief Copies the entire hash state from another object.
*
* \param other The other object to copy the state from.
*
* This function is intended for scenarios where the application needs to
* finalize the state to get an intermediate hash value, but must then
* continue hashing new data into the original state.
*
* In the following example, h1 will be the hash over data1 and h2 will
* be the hash over data1 concatenated with data2:
*
* \code
* // Hash the initial data.
* SHA256 hash1;
* hash1.update(data1, sizeof(data1));
*
* // Copy the hash state and finalize to create h1.
* SHA256 hash2;
* hash2.copyFrom(hash1);
* hash2.finalize(h1, sizeof(h1));
*
* // Continue adding data to the original unfinalized hash.
* hash1.update(data2, sizeof(data2));
*
* // Get the final hash value h2.
* hash1.finalize(h2, sizeof(h2));
* \endcode
*/
void SHA256::copyFrom(const SHA256 &other)
{
state = other.state;
}
/**
* \brief Processes a single 512-bit chunk with the core SHA-256 algorithm.
*
* Reference: http://en.wikipedia.org/wiki/SHA-2
*/
void SHA256::processChunk()
{
// Round constants for SHA-256.
static uint32_t const k[64] PROGMEM = {
0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
};
// Convert the first 16 words from big endian to host byte order.
uint8_t index;
for (index = 0; index < 16; ++index)
state.w[index] = be32toh(state.w[index]);
// Initialise working variables to the current hash value.
uint32_t a = state.h[0];
uint32_t b = state.h[1];
uint32_t c = state.h[2];
uint32_t d = state.h[3];
uint32_t e = state.h[4];
uint32_t f = state.h[5];
uint32_t g = state.h[6];
uint32_t h = state.h[7];
// Perform the first 16 rounds of the compression function main loop.
uint32_t temp1, temp2;
for (index = 0; index < 16; ++index) {
temp1 = h + pgm_read_dword(k + index) + state.w[index] +
(rightRotate6(e) ^ rightRotate11(e) ^ rightRotate25(e)) +
((e & f) ^ ((~e) & g));
temp2 = (rightRotate2(a) ^ rightRotate13(a) ^ rightRotate22(a)) +
((a & b) ^ (a & c) ^ (b & c));
h = g;
g = f;
f = e;
e = d + temp1;
d = c;
c = b;
b = a;
a = temp1 + temp2;
}
// Perform the 48 remaining rounds. We expand the first 16 words to
// 64 in-place in the "w" array. This saves 192 bytes of memory
// that would have otherwise need to be allocated to the "w" array.
for (; index < 64; ++index) {
// Expand the next word.
temp1 = state.w[(index - 15) & 0x0F];
temp2 = state.w[(index - 2) & 0x0F];
temp1 = state.w[index & 0x0F] =
state.w[(index - 16) & 0x0F] + state.w[(index - 7) & 0x0F] +
(rightRotate7(temp1) ^ rightRotate18(temp1) ^ (temp1 >> 3)) +
(rightRotate17(temp2) ^ rightRotate19(temp2) ^ (temp2 >> 10));
// Perform the round.
temp1 = h + pgm_read_dword(k + index) + temp1 +
(rightRotate6(e) ^ rightRotate11(e) ^ rightRotate25(e)) +
((e & f) ^ ((~e) & g));
temp2 = (rightRotate2(a) ^ rightRotate13(a) ^ rightRotate22(a)) +
((a & b) ^ (a & c) ^ (b & c));
h = g;
g = f;
f = e;
e = d + temp1;
d = c;
c = b;
b = a;
a = temp1 + temp2;
}
// Add the compressed chunk to the current hash value.
state.h[0] += a;
state.h[1] += b;
state.h[2] += c;
state.h[3] += d;
state.h[4] += e;
state.h[5] += f;
state.h[6] += g;
state.h[7] += h;
// Attempt to clean up the stack.
a = b = c = d = e = f = g = h = temp1 = temp2 = 0;
}