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mirror of https://github.com/taigrr/arduinolibs synced 2025-01-18 04:33:12 -08:00

ACORN-128 AEAD cipher

This commit is contained in:
Rhys Weatherley 2018-04-21 17:50:42 +10:00
parent 5ca5f805d2
commit 91bffb9d1f
8 changed files with 1213 additions and 1 deletions

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@ -656,6 +656,7 @@ WARN_LOGFILE =
# with spaces.
INPUT = ../libraries/Crypto \
../libraries/CryptoLW/src \
../libraries/NewHope \
../libraries/RingOscillatorNoiseSource \
../libraries/TransistorNoiseSource \

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@ -29,7 +29,7 @@
\li Block ciphers: AES128, AES192, AES256, Speck
\li Block cipher modes: CTR, CFB, CBC, OFB, EAX, GCM, XTS
\li Stream ciphers: ChaCha
\li Authenticated encryption with associated data (AEAD): ChaChaPoly, EAX, GCM
\li Authenticated encryption with associated data (AEAD): ChaChaPoly, EAX, GCM, Acorn128
\li Hash algorithms: SHA256, SHA512, SHA3_256, SHA3_512, BLAKE2s, BLAKE2b (regular and HMAC modes)
\li Extendable output functions (XOF's): SHAKE128, SHAKE256
\li Message authenticators: Poly1305, GHASH, OMAC
@ -206,6 +206,7 @@ All figures are for the Arduino Due running at 84 MHz:
<tr><td>EAX&lt;AES256&gt;</td><td align="right">16.99us</td><td align="right">16.99us</td><td align="right">322.92us</td><td align="right">344</td></tr>
<tr><td>EAX&lt;Speck&gt; (256-bit key)</td><td align="right">2.80us</td><td align="right">2.80us</td><td align="right">81.63us</td><td align="right">384</td></tr>
<tr><td>EAX&lt;SpeckTiny&gt; (256-bit key)</td><td align="right">6.69us</td><td align="right">6.69us</td><td align="right">110.91us</td><td align="right">144</td></tr>
<tr><td>Acorn128</td><td align="right">0.75us</td><td align="right">0.75us</td><td align="right">175.70us</td><td align="right">64</td></tr>
<tr><td colspan="5"> </td></tr>
<tr><td>Hash Algorithm</td><td align="right">Hashing (per byte)</td><td align="right">Finalization</td><td> </td><td>State Size (bytes)</td></tr>
<tr><td>SHA256</td><td align="right">1.15us</td><td align="right">76.60us</td><td align="right"> </td><td align="right">120</td></tr>

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@ -0,0 +1,415 @@
/*
* Copyright (C) 2018 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.
*/
/*
This example runs tests on the Acorn128 implementation to verify
correct behaviour.
*/
#include <Crypto.h>
#include <CryptoLW.h>
#include <Acorn128.h>
#include "utility/ProgMemUtil.h"
#define MAX_PLAINTEXT_LEN 73
#define MAX_AUTHDATA_LEN 39
struct TestVector
{
const char *name;
uint8_t key[16];
uint8_t plaintext[MAX_PLAINTEXT_LEN];
uint8_t ciphertext[MAX_PLAINTEXT_LEN];
uint8_t authdata[MAX_AUTHDATA_LEN];
uint8_t iv[16];
uint8_t tag[16];
size_t authsize;
size_t datasize;
};
// Test vectors for Acorn128 from the specification.
static TestVector const testVectorAcorn128_1 PROGMEM = {
.name = "Acorn128 #1",
.key = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
.plaintext = {0},
.ciphertext = {0},
.authdata = {0},
.iv = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
.tag = {0x83, 0x5e, 0x53, 0x17, 0x89, 0x6e, 0x86, 0xb2,
0x44, 0x71, 0x43, 0xc7, 0x4f, 0x6f, 0xfc, 0x1e},
.authsize = 0,
.datasize = 0
};
static TestVector const testVectorAcorn128_2 PROGMEM = {
.name = "Acorn128 #2",
.key = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
.plaintext = {0x01},
.ciphertext = {0x2b},
.authdata = {0},
.iv = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
.tag = {0x4b, 0x60, 0x64, 0x0e, 0x26, 0xf0, 0xa9, 0x9d,
0xd0, 0x1f, 0x93, 0xbf, 0x63, 0x49, 0x97, 0xcb},
.authsize = 0,
.datasize = 1
};
static TestVector const testVectorAcorn128_3 PROGMEM = {
.name = "Acorn128 #3",
.key = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
.plaintext = {0},
.ciphertext = {0},
.authdata = {0x01},
.iv = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
.tag = {0x98, 0x2e, 0xf7, 0xd1, 0xbb, 0xa7, 0xf8, 0x9a,
0x15, 0x75, 0x29, 0x7a, 0x09, 0x5c, 0xd7, 0xf2},
.authsize = 1,
.datasize = 0
};
static TestVector const testVectorAcorn128_4 PROGMEM = {
.name = "Acorn128 #4",
.key = {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f},
.plaintext = {0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01},
.ciphertext = {0x86, 0x80, 0x1f, 0xa8, 0x9e, 0x33, 0xd9, 0x92,
0x35, 0xdd, 0x4d, 0x1a, 0x72, 0xce, 0x00, 0x1a},
.authdata = {0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01},
.iv = {0x00, 0x03, 0x06, 0x09, 0x0c, 0x0f, 0x12, 0x15,
0x18, 0x1b, 0x1e, 0x21, 0x24, 0x27, 0x2a, 0x2d},
.tag = {0xd9, 0xc6, 0x6b, 0x4a, 0xdb, 0x3c, 0xde, 0x07,
0x3e, 0x63, 0x50, 0xcc, 0x7e, 0x23, 0x7e, 0x01},
.authsize = 16,
.datasize = 16
};
static TestVector const testVectorAcorn128_5 PROGMEM = {
.name = "Acorn128 #5",
.key = {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f},
.plaintext = {0x00, 0x07, 0x0e, 0x15, 0x1c, 0x23, 0x2a, 0x31,
0x38, 0x3f, 0x46, 0x4d, 0x54, 0x5b, 0x62, 0x69,
0x70, 0x77, 0x7e, 0x85, 0x8c, 0x93, 0x9a, 0xa1,
0xa8, 0xaf, 0xb6, 0xbd, 0xc4, 0xcb, 0xd2, 0xd9,
0xe0, 0xe7, 0xee, 0xf5, 0xfc, 0x03, 0x0a, 0x11,
0x18, 0x1f, 0x26, 0x2d, 0x34, 0x3b, 0x42, 0x49,
0x50, 0x57, 0x5e, 0x65, 0x6c, 0x73, 0x7a, 0x81,
0x88, 0x8f, 0x96, 0x9d, 0xa4, 0xab, 0xb2, 0xb9,
0xc0, 0xc7, 0xce, 0xd5, 0xdc, 0xe3, 0xea, 0xf1,
0xf8},
.ciphertext = {0xe7, 0xef, 0x31, 0x63, 0x78, 0x44, 0x46, 0x44,
0x70, 0x5c, 0x43, 0x81, 0xc8, 0x88, 0x83, 0x3b,
0x6d, 0x62, 0xa7, 0x49, 0x00, 0x5a, 0xb8, 0xfa,
0x14, 0x6a, 0x85, 0x90, 0x4d, 0x5e, 0x5a, 0xb7,
0x7c, 0x57, 0x58, 0x21, 0x58, 0x39, 0x5d, 0x8f,
0xe6, 0xb6, 0x66, 0xe6, 0xc8, 0x51, 0x77, 0x64,
0x8a, 0xeb, 0x77, 0x84, 0xcf, 0x2e, 0xea, 0xed,
0x3c, 0x22, 0xe7, 0xe9, 0x6b, 0xf5, 0x90, 0x09,
0xcd, 0x7a, 0xd2, 0x1b, 0xa5, 0xdf, 0x1a, 0x0f,
0xc0},
.authdata = {0x00, 0x05, 0x0a, 0x0f, 0x14, 0x19, 0x1e, 0x23,
0x28, 0x2d, 0x32, 0x37, 0x3c, 0x41, 0x46, 0x4b,
0x50, 0x55, 0x5a, 0x5f, 0x64, 0x69, 0x6e, 0x73,
0x78, 0x7d, 0x82, 0x87, 0x8c, 0x91, 0x96, 0x9b,
0xa0, 0xa5, 0xaa, 0xaf, 0xb4, 0xb9, 0xbe},
.iv = {0x00, 0x03, 0x06, 0x09, 0x0c, 0x0f, 0x12, 0x15,
0x18, 0x1b, 0x1e, 0x21, 0x24, 0x27, 0x2a, 0x2d},
.tag = {0x51, 0xb4, 0xbd, 0x86, 0xc6, 0x8c, 0xcf, 0x06,
0x82, 0xf5, 0x69, 0x5d, 0x26, 0x67, 0xd5, 0x35},
.authsize = 39,
.datasize = 73
};
TestVector testVector;
Acorn128 acorn;
byte buffer[MAX_PLAINTEXT_LEN];
bool testCipher_N(Acorn128 *cipher, const struct TestVector *test, size_t inc)
{
size_t posn, len;
uint8_t tag[16];
if (!inc)
inc = 1;
cipher->clear();
if (!cipher->setKey(test->key, 16)) {
Serial.print("setKey ");
return false;
}
if (!cipher->setIV(test->iv, 16)) {
Serial.print("setIV ");
return false;
}
memset(buffer, 0xBA, sizeof(buffer));
for (posn = 0; posn < test->authsize; posn += inc) {
len = test->authsize - posn;
if (len > inc)
len = inc;
cipher->addAuthData(test->authdata + posn, len);
}
for (posn = 0; posn < test->datasize; posn += inc) {
len = test->datasize - posn;
if (len > inc)
len = inc;
cipher->encrypt(buffer + posn, test->plaintext + posn, len);
}
if (memcmp(buffer, test->ciphertext, test->datasize) != 0) {
Serial.print(buffer[0], HEX);
Serial.print("->");
Serial.print(test->ciphertext[0], HEX);
return false;
}
cipher->computeTag(tag, sizeof(tag));
if (memcmp(tag, test->tag, sizeof(tag)) != 0) {
Serial.print("computed wrong tag ... ");
return false;
}
cipher->setKey(test->key, 16);
cipher->setIV(test->iv, 16);
for (posn = 0; posn < test->authsize; posn += inc) {
len = test->authsize - posn;
if (len > inc)
len = inc;
cipher->addAuthData(test->authdata + posn, len);
}
for (posn = 0; posn < test->datasize; posn += inc) {
len = test->datasize - posn;
if (len > inc)
len = inc;
cipher->decrypt(buffer + posn, test->ciphertext + posn, len);
}
if (memcmp(buffer, test->plaintext, test->datasize) != 0)
return false;
if (!cipher->checkTag(tag, sizeof(tag))) {
Serial.print("tag did not check ... ");
return false;
}
return true;
}
void testCipher(Acorn128 *cipher, const struct TestVector *test)
{
bool ok;
memcpy_P(&testVector, test, sizeof(TestVector));
test = &testVector;
Serial.print(test->name);
Serial.print(" ... ");
ok = testCipher_N(cipher, test, test->datasize);
ok &= testCipher_N(cipher, test, 1);
ok &= testCipher_N(cipher, test, 2);
ok &= testCipher_N(cipher, test, 5);
ok &= testCipher_N(cipher, test, 8);
ok &= testCipher_N(cipher, test, 13);
ok &= testCipher_N(cipher, test, 16);
if (ok)
Serial.println("Passed");
else
Serial.println("Failed");
}
void perfCipherSetKey(Acorn128 *cipher, const struct TestVector *test)
{
unsigned long start;
unsigned long elapsed;
int count;
memcpy_P(&testVector, test, sizeof(TestVector));
test = &testVector;
Serial.print(test->name);
Serial.print(" SetKey ... ");
start = micros();
for (count = 0; count < 1000; ++count) {
cipher->setKey(test->key, 16);
cipher->setIV(test->iv, 16);
}
elapsed = micros() - start;
Serial.print(elapsed / 1000.0);
Serial.print("us per operation, ");
Serial.print((1000.0 * 1000000.0) / elapsed);
Serial.println(" per second");
}
void perfCipherEncrypt(Acorn128 *cipher, const struct TestVector *test)
{
unsigned long start;
unsigned long elapsed;
int count;
memcpy_P(&testVector, test, sizeof(TestVector));
test = &testVector;
Serial.print(test->name);
Serial.print(" Encrypt ... ");
cipher->setKey(test->key, 16);
cipher->setIV(test->iv, 16);
start = micros();
for (count = 0; count < 500; ++count) {
cipher->encrypt(buffer, buffer, 128);
}
elapsed = micros() - start;
Serial.print(elapsed / (128.0 * 500.0));
Serial.print("us per byte, ");
Serial.print((128.0 * 500.0 * 1000000.0) / elapsed);
Serial.println(" bytes per second");
}
void perfCipherDecrypt(Acorn128 *cipher, const struct TestVector *test)
{
unsigned long start;
unsigned long elapsed;
int count;
memcpy_P(&testVector, test, sizeof(TestVector));
test = &testVector;
Serial.print(test->name);
Serial.print(" Decrypt ... ");
cipher->setKey(test->key, 16);
cipher->setIV(test->iv, 16);
start = micros();
for (count = 0; count < 500; ++count) {
cipher->decrypt(buffer, buffer, 128);
}
elapsed = micros() - start;
Serial.print(elapsed / (128.0 * 500.0));
Serial.print("us per byte, ");
Serial.print((128.0 * 500.0 * 1000000.0) / elapsed);
Serial.println(" bytes per second");
}
void perfCipherAddAuthData(Acorn128 *cipher, const struct TestVector *test)
{
unsigned long start;
unsigned long elapsed;
int count;
memcpy_P(&testVector, test, sizeof(TestVector));
test = &testVector;
Serial.print(test->name);
Serial.print(" AddAuthData ... ");
cipher->setKey(test->key, 16);
cipher->setIV(test->iv, 16);
start = micros();
memset(buffer, 0xBA, 128);
for (count = 0; count < 500; ++count) {
cipher->addAuthData(buffer, 128);
}
elapsed = micros() - start;
Serial.print(elapsed / (128.0 * 500.0));
Serial.print("us per byte, ");
Serial.print((128.0 * 500.0 * 1000000.0) / elapsed);
Serial.println(" bytes per second");
}
void perfCipherComputeTag(Acorn128 *cipher, const struct TestVector *test)
{
unsigned long start;
unsigned long elapsed;
int count;
memcpy_P(&testVector, test, sizeof(TestVector));
test = &testVector;
Serial.print(test->name);
Serial.print(" ComputeTag ... ");
cipher->setKey(test->key, 16);
cipher->setIV(test->iv, 16);
start = micros();
for (count = 0; count < 1000; ++count) {
cipher->computeTag(buffer, 16);
}
elapsed = micros() - start;
Serial.print(elapsed / 1000.0);
Serial.print("us per operation, ");
Serial.print((1000.0 * 1000000.0) / elapsed);
Serial.println(" per second");
}
void perfCipher(Acorn128 *cipher, const struct TestVector *test)
{
perfCipherSetKey(cipher, test);
perfCipherEncrypt(cipher, test);
perfCipherDecrypt(cipher, test);
perfCipherAddAuthData(cipher, test);
perfCipherComputeTag(cipher, test);
}
void setup()
{
Serial.begin(9600);
Serial.println();
Serial.print("State Size ... ");
Serial.println(sizeof(Acorn128));
Serial.println();
Serial.println("Test Vectors:");
testCipher(&acorn, &testVectorAcorn128_1);
testCipher(&acorn, &testVectorAcorn128_2);
testCipher(&acorn, &testVectorAcorn128_3);
testCipher(&acorn, &testVectorAcorn128_4);
testCipher(&acorn, &testVectorAcorn128_5);
Serial.println();
Serial.println("Performance Tests:");
perfCipher(&acorn, &testVectorAcorn128_4);
}
void loop()
{
}

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@ -0,0 +1 @@
Acorn128 KEYWORD1

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@ -0,0 +1,10 @@
name=CryptoLW
version=1.0.0
author=Rhys Weatherley <rhys.weatherley@gmail.com>
maintainer=Rhys Weatherley <rhys.weatherley@gmail.com>
sentence=Light-weight algorithms for the Arduino Cryptography Library
paragraph=This library provides implementations of various "light-weight" cryptography algorithms, designed for resource-constrained environments.
category=Communication
url=https://github.com/rweather/arduinolibs
architectures=*
includes=CryptoLW.h

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@ -0,0 +1,668 @@
/*
* Copyright (C) 2018 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 "Acorn128.h"
#include "Crypto.h"
#include "utility/EndianUtil.h"
#include <string.h>
/**
* \class Acorn128 Acorn128.h <Acorn128.h>
* \brief ACORN-128 authenticated cipher.
*
* Acorn128 is an authenticated cipher designed for memory-limited
* environments with a 128-bit key, a 128-bit initialization vector,
* and a 128-bit authentication tag. It was one of the finalists
* in the CAESAR AEAD competition.
*
* References: http://competitions.cr.yp.to/round3/acornv3.pdf,
* http://competitions.cr.yp.to/caesar-submissions.html
*
* \sa AuthenticatedCipher
*/
/**
* \brief Constructs a new Acorn128 authenticated cipher.
*/
Acorn128::Acorn128()
{
state.authDone = 0;
}
/**
* \brief Destroys this Acorn128 authenticated cipher.
*/
Acorn128::~Acorn128()
{
clean(state);
}
/**
* \brief Gets the size of the Acorn128 key in bytes.
*
* \return Always returns 16, indicating a 128-bit key.
*/
size_t Acorn128::keySize() const
{
return 16;
}
/**
* \brief Gets the size of the Acorn128 initialization vector in bytes.
*
* \return Always returns 16, indicating a 128-bit IV.
*
* Authentication tags may be truncated to 8 bytes, but the algorithm authors
* recommend using a full 16-byte tag.
*/
size_t Acorn128::ivSize() const
{
return 16;
}
/**
* \brief Gets the size of the Acorn128 authentication tag in bytes.
*
* \return Always returns 16, indicating a 128-bit authentication tag.
*/
size_t Acorn128::tagSize() const
{
return 16;
}
// Acorn128 constants for ca and cb.
#define CA_0 ((uint32_t)0x00000000)
#define CA_1 ((uint32_t)0xFFFFFFFF)
#define CB_0 ((uint32_t)0x00000000)
#define CB_1 ((uint32_t)0xFFFFFFFF)
#define CA_0_BYTE ((uint8_t)0x00)
#define CA_1_BYTE ((uint8_t)0xFF)
#define CB_0_BYTE ((uint8_t)0x00)
#define CB_1_BYTE ((uint8_t)0xFF)
// maj() and ch() functions for mixing the state.
#define maj(x, y, z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
#define ch(x, y, z) (((x) & (y)) ^ ((~(x)) & (z)))
/**
* \brief Encrypts an 8-bit byte using Acorn128.
*
* \param state The state for the Acorn128 cipher.
* \param plaintext The plaintext byte.
* \param ca The ca constant.
* \param cb The cb constant.
*
* \return The ciphertext byte.
*/
static uint8_t acornEncrypt8
(Acorn128State *state, uint8_t plaintext, uint8_t ca, uint8_t cb)
{
// Extract out various sub-parts of the state as 8-bit bytes.
#define s_extract_8(name, shift) \
((uint8_t)(state->name##_l >> (shift)))
uint8_t s244 = s_extract_8(s6, 14);
uint8_t s235 = s_extract_8(s6, 5);
uint8_t s196 = s_extract_8(s5, 3);
uint8_t s160 = s_extract_8(s4, 6);
uint8_t s111 = s_extract_8(s3, 4);
uint8_t s66 = s_extract_8(s2, 5);
uint8_t s23 = s_extract_8(s1, 23);
uint8_t s12 = s_extract_8(s1, 12);
// Update the LFSR's.
uint8_t s7_l = state->s7 ^ s235 ^ state->s6_l;
state->s6_l ^= s196 ^ ((uint8_t)(state->s5_l));
state->s5_l ^= s160 ^ ((uint8_t)(state->s4_l));
state->s4_l ^= s111 ^ ((uint8_t)(state->s3_l));
state->s3_l ^= s66 ^ ((uint8_t)(state->s2_l));
state->s2_l ^= s23 ^ ((uint8_t)(state->s1_l));
// Generate the next 8 keystream bits.
// k = S[12] ^ S[154] ^ maj(S[235], S[61], S[193])
// ^ ch(S[230], S[111], S[66])
uint8_t ks = s12 ^ state->s4_l ^
maj(s235, state->s2_l, state->s5_l) ^
ch(state->s6_l, s111, s66);
// Generate the next 8 non-linear feedback bits.
// f = S[0] ^ ~S[107] ^ maj(S[244], S[23], S[160])
// ^ (ca & S[196]) ^ (cb & ks)
// f ^= plaintext
uint8_t f = state->s1_l ^ (~state->s3_l) ^
maj(s244, s23, s160) ^ (ca & s196) ^ (cb & ks);
f ^= plaintext;
// Shift the state downwards by 8 bits.
#define s_shift_8(name1, name2, shift) \
(state->name1##_l = (state->name1##_l >> 8) | \
(((uint32_t)(state->name1##_h)) << 24), \
state->name1##_h = (state->name1##_h >> 8) | \
((state->name2##_l & 0xFF) << ((shift) - 40)))
#define s_shift_8_mixed(name1, name2, shift) \
(state->name1##_l = (state->name1##_l >> 8) | \
(((uint32_t)(state->name1##_h)) << 24) | \
(state->name2##_l << ((shift) - 8)), \
state->name1##_h = ((state->name2##_l & 0xFF) >> (40 - (shift))))
s7_l ^= (f << 4);
state->s7 = f >> 4;
s_shift_8(s1, s2, 61);
s_shift_8(s2, s3, 46);
s_shift_8(s3, s4, 47);
s_shift_8_mixed(s4, s5, 39);
s_shift_8_mixed(s5, s6, 37);
state->s6_l = (state->s6_l >> 8) | (state->s6_h << 24);
state->s6_h = (state->s6_h >> 8) | (((uint32_t)s7_l) << 19);
// Return the ciphertext byte to the caller.
return plaintext ^ ks;
}
/**
* \brief Encrypts a 32-bit word using Acorn128.
*
* \param state The state for the Acorn128 cipher.
* \param plaintext The plaintext word.
* \param ca The ca constant.
* \param cb The cb constant.
*
* \return The ciphertext word.
*/
static uint32_t acornEncrypt32
(Acorn128State *state, uint32_t plaintext, uint32_t ca, uint32_t cb)
{
// Extract out various sub-parts of the state as 32-bit words.
#define s_extract_32(name, shift) \
((state->name##_l >> (shift)) | \
(((uint32_t)(state->name##_h)) << (32 - (shift))))
uint32_t s244 = s_extract_32(s6, 14);
uint32_t s235 = s_extract_32(s6, 5);
uint32_t s196 = s_extract_32(s5, 3);
uint32_t s160 = s_extract_32(s4, 6);
uint32_t s111 = s_extract_32(s3, 4);
uint32_t s66 = s_extract_32(s2, 5);
uint32_t s23 = s_extract_32(s1, 23);
uint32_t s12 = s_extract_32(s1, 12);
// Update the LFSR's.
uint32_t s7_l = state->s7 ^ s235 ^ state->s6_l;
state->s6_l ^= s196 ^ state->s5_l;
state->s5_l ^= s160 ^ state->s4_l;
state->s4_l ^= s111 ^ state->s3_l;
state->s3_l ^= s66 ^ state->s2_l;
state->s2_l ^= s23 ^ state->s1_l;
// Generate the next 32 keystream bits.
// k = S[12] ^ S[154] ^ maj(S[235], S[61], S[193])
// ^ ch(S[230], S[111], S[66])
uint32_t ks = s12 ^ state->s4_l ^
maj(s235, state->s2_l, state->s5_l) ^
ch(state->s6_l, s111, s66);
// Generate the next 32 non-linear feedback bits.
// f = S[0] ^ ~S[107] ^ maj(S[244], S[23], S[160])
// ^ (ca & S[196]) ^ (cb & ks)
// f ^= plaintext
uint32_t f = state->s1_l ^ (~state->s3_l) ^
maj(s244, s23, s160) ^ (ca & s196) ^ (cb & ks);
f ^= plaintext;
// Shift the state downwards by 32 bits.
#define s_shift_32(name1, name2, shift) \
(state->name1##_l = state->name1##_h | (state->name2##_l << (shift)), \
state->name1##_h = (state->name2##_l >> (32 - (shift))))
s7_l ^= (f << 4);
state->s7 = (uint8_t)(f >> 28);
s_shift_32(s1, s2, 29);
s_shift_32(s2, s3, 14);
s_shift_32(s3, s4, 15);
s_shift_32(s4, s5, 7);
s_shift_32(s5, s6, 5);
state->s6_l = state->s6_h | (s7_l << 27);
state->s6_h = s7_l >> 5;
// Return the ciphertext word to the caller.
return plaintext ^ ks;
}
/**
* \brief Encrypts a 32-bit word using Acorn128.
*
* \param state The state for the Acorn128 cipher.
* \param plaintext The plaintext word.
*
* \return The ciphertext word.
*
* This version assumes that ca = 1 and cb = 0.
*/
static inline uint32_t acornEncrypt32Fast
(Acorn128State *state, uint32_t plaintext)
{
// Extract out various sub-parts of the state as 32-bit words.
#define s_extract_32(name, shift) \
((state->name##_l >> (shift)) | \
(((uint32_t)(state->name##_h)) << (32 - (shift))))
uint32_t s244 = s_extract_32(s6, 14);
uint32_t s235 = s_extract_32(s6, 5);
uint32_t s196 = s_extract_32(s5, 3);
uint32_t s160 = s_extract_32(s4, 6);
uint32_t s111 = s_extract_32(s3, 4);
uint32_t s66 = s_extract_32(s2, 5);
uint32_t s23 = s_extract_32(s1, 23);
uint32_t s12 = s_extract_32(s1, 12);
// Update the LFSR's.
uint32_t s7_l = state->s7 ^ s235 ^ state->s6_l;
state->s6_l ^= s196 ^ state->s5_l;
state->s5_l ^= s160 ^ state->s4_l;
state->s4_l ^= s111 ^ state->s3_l;
state->s3_l ^= s66 ^ state->s2_l;
state->s2_l ^= s23 ^ state->s1_l;
// Generate the next 32 keystream bits.
// k = S[12] ^ S[154] ^ maj(S[235], S[61], S[193])
// ^ ch(S[230], S[111], S[66])
uint32_t ks = s12 ^ state->s4_l ^
maj(s235, state->s2_l, state->s5_l) ^
ch(state->s6_l, s111, s66);
// Generate the next 32 non-linear feedback bits.
// f = S[0] ^ ~S[107] ^ maj(S[244], S[23], S[160])
// ^ (ca & S[196]) ^ (cb & ks)
// f ^= plaintext
// Note: ca will always be 1 and cb will always be 0.
uint32_t f = state->s1_l ^ (~state->s3_l) ^ maj(s244, s23, s160) ^ s196;
f ^= plaintext;
// Shift the state downwards by 32 bits.
#define s_shift_32(name1, name2, shift) \
(state->name1##_l = state->name1##_h | (state->name2##_l << (shift)), \
state->name1##_h = (state->name2##_l >> (32 - (shift))))
s7_l ^= (f << 4);
state->s7 = (uint8_t)(f >> 28);
s_shift_32(s1, s2, 29);
s_shift_32(s2, s3, 14);
s_shift_32(s3, s4, 15);
s_shift_32(s4, s5, 7);
s_shift_32(s5, s6, 5);
state->s6_l = state->s6_h | (s7_l << 27);
state->s6_h = s7_l >> 5;
// Return the ciphertext word to the caller.
return plaintext ^ ks;
}
/**
* \brief Decrypts an 8-bit byte using Acorn128.
*
* \param state The state for the Acorn128 cipher.
* \param ciphertext The ciphertext byte.
*
* \return The plaintext byte.
*/
static inline uint8_t acornDecrypt8(Acorn128State *state, uint8_t ciphertext)
{
// Extract out various sub-parts of the state as 8-bit bytes.
#define s_extract_8(name, shift) \
((uint8_t)(state->name##_l >> (shift)))
uint8_t s244 = s_extract_8(s6, 14);
uint8_t s235 = s_extract_8(s6, 5);
uint8_t s196 = s_extract_8(s5, 3);
uint8_t s160 = s_extract_8(s4, 6);
uint8_t s111 = s_extract_8(s3, 4);
uint8_t s66 = s_extract_8(s2, 5);
uint8_t s23 = s_extract_8(s1, 23);
uint8_t s12 = s_extract_8(s1, 12);
// Update the LFSR's.
uint8_t s7_l = state->s7 ^ s235 ^ state->s6_l;
state->s6_l ^= s196 ^ ((uint8_t)(state->s5_l));
state->s5_l ^= s160 ^ ((uint8_t)(state->s4_l));
state->s4_l ^= s111 ^ ((uint8_t)(state->s3_l));
state->s3_l ^= s66 ^ ((uint8_t)(state->s2_l));
state->s2_l ^= s23 ^ ((uint8_t)(state->s1_l));
// Generate the next 8 keystream bits and decrypt the ciphertext.
// k = S[12] ^ S[154] ^ maj(S[235], S[61], S[193])
// ^ ch(S[230], S[111], S[66])
uint8_t ks = s12 ^ state->s4_l ^
maj(s235, state->s2_l, state->s5_l) ^
ch(state->s6_l, s111, s66);
uint8_t plaintext = ciphertext ^ ks;
// Generate the next 8 non-linear feedback bits.
// f = S[0] ^ ~S[107] ^ maj(S[244], S[23], S[160])
// ^ (ca & S[196]) ^ (cb & ks)
// f ^= plaintext
// Note: ca will always be 1 and cb will always be 0.
uint8_t f = state->s1_l ^ (~state->s3_l) ^ maj(s244, s23, s160) ^ s196;
f ^= plaintext;
// Shift the state downwards by 8 bits.
#define s_shift_8(name1, name2, shift) \
(state->name1##_l = (state->name1##_l >> 8) | \
(((uint32_t)(state->name1##_h)) << 24), \
state->name1##_h = (state->name1##_h >> 8) | \
((state->name2##_l & 0xFF) << ((shift) - 40)))
#define s_shift_8_mixed(name1, name2, shift) \
(state->name1##_l = (state->name1##_l >> 8) | \
(((uint32_t)(state->name1##_h)) << 24) | \
(state->name2##_l << ((shift) - 8)), \
state->name1##_h = ((state->name2##_l & 0xFF) >> (40 - (shift))))
s7_l ^= (f << 4);
state->s7 = f >> 4;
s_shift_8(s1, s2, 61);
s_shift_8(s2, s3, 46);
s_shift_8(s3, s4, 47);
s_shift_8_mixed(s4, s5, 39);
s_shift_8_mixed(s5, s6, 37);
state->s6_l = (state->s6_l >> 8) | (state->s6_h << 24);
state->s6_h = (state->s6_h >> 8) | (((uint32_t)s7_l) << 19);
// Return the plaintext byte to the caller.
return plaintext;
}
/**
* \brief Decrypts a 32-bit word using Acorn128.
*
* \param state The state for the Acorn128 cipher.
* \param ciphertext The ciphertext word.
*
* \return The plaintext word.
*/
static inline uint32_t acornDecrypt32(Acorn128State *state, uint32_t ciphertext)
{
// Extract out various sub-parts of the state as 32-bit words.
#define s_extract_32(name, shift) \
((state->name##_l >> (shift)) | \
(((uint32_t)(state->name##_h)) << (32 - (shift))))
uint32_t s244 = s_extract_32(s6, 14);
uint32_t s235 = s_extract_32(s6, 5);
uint32_t s196 = s_extract_32(s5, 3);
uint32_t s160 = s_extract_32(s4, 6);
uint32_t s111 = s_extract_32(s3, 4);
uint32_t s66 = s_extract_32(s2, 5);
uint32_t s23 = s_extract_32(s1, 23);
uint32_t s12 = s_extract_32(s1, 12);
// Update the LFSR's.
uint32_t s7_l = state->s7 ^ s235 ^ state->s6_l;
state->s6_l ^= s196 ^ state->s5_l;
state->s5_l ^= s160 ^ state->s4_l;
state->s4_l ^= s111 ^ state->s3_l;
state->s3_l ^= s66 ^ state->s2_l;
state->s2_l ^= s23 ^ state->s1_l;
// Generate the next 32 keystream bits and decrypt the ciphertext.
// k = S[12] ^ S[154] ^ maj(S[235], S[61], S[193])
// ^ ch(S[230], S[111], S[66])
uint32_t ks = s12 ^ state->s4_l ^
maj(s235, state->s2_l, state->s5_l) ^
ch(state->s6_l, s111, s66);
uint32_t plaintext = ciphertext ^ ks;
// Generate the next 32 non-linear feedback bits.
// f = S[0] ^ ~S[107] ^ maj(S[244], S[23], S[160])
// ^ (ca & S[196]) ^ (cb & ks)
// f ^= plaintext
// Note: ca will always be 1 and cb will always be 0.
uint32_t f = state->s1_l ^ (~state->s3_l) ^ maj(s244, s23, s160) ^ s196;
f ^= plaintext;
// Shift the state downwards by 32 bits.
#define s_shift_32(name1, name2, shift) \
(state->name1##_l = state->name1##_h | (state->name2##_l << (shift)), \
state->name1##_h = (state->name2##_l >> (32 - (shift))))
s7_l ^= (f << 4);
state->s7 = (uint8_t)(f >> 28);
s_shift_32(s1, s2, 29);
s_shift_32(s2, s3, 14);
s_shift_32(s3, s4, 15);
s_shift_32(s4, s5, 7);
s_shift_32(s5, s6, 5);
state->s6_l = state->s6_h | (s7_l << 27);
state->s6_h = s7_l >> 5;
// Return the plaintext word to the caller.
return plaintext;
}
/**
* \brief Adds 256 bits of padding to the Acorn128 state.
*
* \param state The state for the Acorn128 cipher.
* \param cb The cb constant for the padding block.
*/
static void acornPad(Acorn128State *state, uint32_t cb)
{
acornEncrypt32(state, 1, CA_1, cb);
acornEncrypt32(state, 0, CA_1, cb);
acornEncrypt32(state, 0, CA_1, cb);
acornEncrypt32(state, 0, CA_1, cb);
acornEncrypt32(state, 0, CA_0, cb);
acornEncrypt32(state, 0, CA_0, cb);
acornEncrypt32(state, 0, CA_0, cb);
acornEncrypt32(state, 0, CA_0, cb);
}
bool Acorn128::setKey(const uint8_t *key, size_t len)
{
// We cannot initialize the key block until we also have the IV.
// So we simply validate the length and save the key away for later.
if (len == 16) {
memcpy(state.k, key, 16);
#if !defined(CRYPTO_LITTLE_ENDIAN)
state.k[0] = le32toh(state.k[0]);
state.k[1] = le32toh(state.k[1]);
state.k[2] = le32toh(state.k[2]);
state.k[3] = le32toh(state.k[3]);
#endif
return true;
} else {
return false;
}
}
bool Acorn128::setIV(const uint8_t *iv, size_t len)
{
if (len != 16)
return false;
// Unpack the iv into four 32-bit words.
uint32_t ivwords[4];
memcpy(ivwords, iv, 16);
#if !defined(CRYPTO_LITTLE_ENDIAN)
ivwords[0] = le32toh(ivwords[0]);
ivwords[1] = le32toh(ivwords[1]);
ivwords[2] = le32toh(ivwords[2]);
ivwords[3] = le32toh(ivwords[3]);
#endif
// Initialize the state to zero.
state.s1_l = 0;
state.s1_h = 0;
state.s2_l = 0;
state.s2_h = 0;
state.s3_h = 0;
state.s3_l = 0;
state.s4_l = 0;
state.s4_h = 0;
state.s5_h = 0;
state.s5_l = 0;
state.s6_l = 0;
state.s6_h = 0;
state.s7 = 0;
state.authDone = 0;
// Run the cipher for 1792 steps, 32 at a time,
// which mixes the key and IV into the cipher state.
acornEncrypt32(&state, state.k[0], CA_1, CB_1);
acornEncrypt32(&state, state.k[1], CA_1, CB_1);
acornEncrypt32(&state, state.k[2], CA_1, CB_1);
acornEncrypt32(&state, state.k[3], CA_1, CB_1);
acornEncrypt32(&state, ivwords[0], CA_1, CB_1);
acornEncrypt32(&state, ivwords[1], CA_1, CB_1);
acornEncrypt32(&state, ivwords[2], CA_1, CB_1);
acornEncrypt32(&state, ivwords[3], CA_1, CB_1);
acornEncrypt32(&state, state.k[0] ^ 0x00000001, CA_1, CB_1);
acornEncrypt32(&state, state.k[1], CA_1, CB_1);
acornEncrypt32(&state, state.k[2], CA_1, CB_1);
acornEncrypt32(&state, state.k[3], CA_1, CB_1);
for (uint8_t i = 0; i < 11; ++i) {
acornEncrypt32(&state, state.k[0], CA_1, CB_1);
acornEncrypt32(&state, state.k[1], CA_1, CB_1);
acornEncrypt32(&state, state.k[2], CA_1, CB_1);
acornEncrypt32(&state, state.k[3], CA_1, CB_1);
}
// Clean up and exit.
clean(ivwords);
return true;
}
void Acorn128::encrypt(uint8_t *output, const uint8_t *input, size_t len)
{
uint32_t temp;
if (!state.authDone) {
acornPad(&state, CB_1);
state.authDone = 1;
}
while (len >= 4) {
uint32_t temp = ((uint32_t)input[0]) |
(((uint32_t)input[1]) << 8) |
(((uint32_t)input[2]) << 16) |
(((uint32_t)input[3]) << 24);
temp = acornEncrypt32Fast(&state, temp);
output[0] = (uint8_t)temp;
output[1] = (uint8_t)(temp >> 8);
output[2] = (uint8_t)(temp >> 16);
output[3] = (uint8_t)(temp >> 24);
input += 4;
output += 4;
len -= 4;
}
while (len > 0) {
*output++ = acornEncrypt8(&state, *input++, CA_1_BYTE, CB_0_BYTE);
--len;
}
}
void Acorn128::decrypt(uint8_t *output, const uint8_t *input, size_t len)
{
uint32_t temp;
if (!state.authDone) {
acornPad(&state, CB_1);
state.authDone = 1;
}
while (len >= 4) {
uint32_t temp = ((uint32_t)input[0]) |
(((uint32_t)input[1]) << 8) |
(((uint32_t)input[2]) << 16) |
(((uint32_t)input[3]) << 24);
temp = acornDecrypt32(&state, temp);
output[0] = (uint8_t)temp;
output[1] = (uint8_t)(temp >> 8);
output[2] = (uint8_t)(temp >> 16);
output[3] = (uint8_t)(temp >> 24);
input += 4;
output += 4;
len -= 4;
}
while (len > 0) {
*output++ = acornDecrypt8(&state, *input++);
--len;
}
}
void Acorn128::addAuthData(const void *data, size_t len)
{
// Cannot add any more auth data if we've started to encrypt or decrypt.
if (state.authDone)
return;
// Encrypt the auth data with ca = 1, cb = 1.
const uint8_t *input = (const uint8_t *)data;
while (len >= 4) {
uint32_t temp = ((uint32_t)input[0]) |
(((uint32_t)input[1]) << 8) |
(((uint32_t)input[2]) << 16) |
(((uint32_t)input[3]) << 24);
acornEncrypt32(&state, temp, CA_1, CB_1);
input += 4;
len -= 4;
}
while (len > 0) {
acornEncrypt8(&state, *input++, CA_1_BYTE, CB_1_BYTE);
--len;
}
}
void Acorn128::computeTag(void *tag, size_t len)
{
// Finalize the data and apply padding.
if (!state.authDone)
acornPad(&state, CB_1);
acornPad(&state, CB_0);
// Encrypt 768 zero bits and extract the last 128 for the tag.
uint32_t temp[4];
for (uint8_t i = 0; i < 20; ++i)
acornEncrypt32(&state, 0, CA_1, CB_1);
temp[0] = acornEncrypt32(&state, 0, CA_1, CB_1);
temp[1] = acornEncrypt32(&state, 0, CA_1, CB_1);
temp[2] = acornEncrypt32(&state, 0, CA_1, CB_1);
temp[3] = acornEncrypt32(&state, 0, CA_1, CB_1);
#if !defined(CRYPTO_LITTLE_ENDIAN)
temp[0] = htole32(temp[0]);
temp[1] = htole32(temp[1]);
temp[2] = htole32(temp[2]);
temp[3] = htole32(temp[3]);
#endif
// Truncate to the requested length and return the value.
if (len > 16)
len = 16;
memcpy(tag, temp, len);
clean(temp);
}
bool Acorn128::checkTag(const void *tag, size_t len)
{
// Can never match if the expected tag length is too long.
if (len > 16)
return false;
// Compute the authentication tag and check it.
uint8_t temp[16];
computeTag(temp, len);
bool equal = secure_compare(temp, tag, len);
clean(temp);
return equal;
}
/**
* \brief Clears all security-sensitive state from this cipher object.
*/
void Acorn128::clear()
{
clean(state);
}

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@ -0,0 +1,87 @@
/*
* Copyright (C) 2018 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.
*/
#ifndef CRYPTO_ACORN128_H
#define CRYPTO_ACORN128_H
#include "AuthenticatedCipher.h"
/** @cond acorn128_state */
// The ACORN-128 state consists of 293 bits split across six
// Linear Feedback Shift Registers (LFSR's) and 4 bits spare.
// In this implementation, each LFSR is represented by a
// 48-bit or 64-bit register split into 32/16-bit words.
// The optimized reference implementation from the algorithm's
// authors uses 7 uint64_t registers, for a total state size
// of 448 bits. This version uses 328 bits for same data and
// should be efficient on 8-bit and 32-bit microcontrollers.
typedef struct
{
uint32_t k[4]; // Cached copy of the key for multiple requests.
uint32_t s1_l; // LFSR1, 61 bits, 0..60, low word
uint32_t s1_h; // LFSR1, high word
uint32_t s2_l; // LFSR2, 46 bits, 61..106, low word
uint16_t s2_h; // LFSR2, high word
uint16_t s3_h; // LFSR3, 47 bits, 107..153, high word
uint32_t s3_l; // LFSR3, low word
uint32_t s4_l; // LFSR4, 39 bits, 154..192, low word
uint16_t s4_h; // LFSR4, high word
uint16_t s5_h; // LFSR5, 37 bits, 193..229, high word
uint32_t s5_l; // LFSR5, low word
uint32_t s6_l; // LFSR6, 59 bits, 230..288, low word
uint32_t s6_h; // LFSR6, high word
uint8_t s7; // Top most 4 bits, 289..292
uint8_t authDone; // Non-zero once authentication is done.
} Acorn128State;
/** @endcond */
class Acorn128 : public AuthenticatedCipher
{
public:
Acorn128();
virtual ~Acorn128();
size_t keySize() const;
size_t ivSize() const;
size_t tagSize() const;
bool setKey(const uint8_t *key, size_t len);
bool setIV(const uint8_t *iv, size_t len);
void encrypt(uint8_t *output, const uint8_t *input, size_t len);
void decrypt(uint8_t *output, const uint8_t *input, size_t len);
void addAuthData(const void *data, size_t len);
void computeTag(void *tag, size_t len);
bool checkTag(const void *tag, size_t len);
void clear();
private:
Acorn128State state;
};
#endif

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@ -0,0 +1,29 @@
/*
* Copyright (C) 2018 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.
*/
#ifndef CRYPTO_LW_H
#define CRYPTO_LW_H
// This header exists to make the Arudino IDE add the library to the
// include and link paths when the sketch includes <CryptoLW.h>.
#endif