From b2f865182d49d91288114695e402ccac5f5413fb Mon Sep 17 00:00:00 2001 From: Mark Haines Date: Sat, 21 Feb 2015 01:36:15 +0000 Subject: [PATCH] Finish and test crypto primitives --- include/axolotl/crypto.hh | 8 ++- src/crypto.cpp | 59 ++++++++++------- tests/test_crypto.cpp | 134 +++++++++++++++++++++++++++++++++++++- 3 files changed, 174 insertions(+), 27 deletions(-) diff --git a/include/axolotl/crypto.hh b/include/axolotl/crypto.hh index 9691228..3f7b71e 100644 --- a/include/axolotl/crypto.hh +++ b/include/axolotl/crypto.hh @@ -19,7 +19,7 @@ Curve25519KeyPair generate_key( ); -const std::size_t CURVE25519_SHARED_SECRET_LENGTH = 16; +const std::size_t CURVE25519_SHARED_SECRET_LENGTH = 32; void curve25519_shared_secret( @@ -68,6 +68,12 @@ void aes_decrypt_cbc( ); +void sha256( + std::uint8_t const * input, std::size_t input_length, + std::uint8_t * output +); + + const std::size_t HMAC_SHA256_OUTPUT_LENGTH = 32; diff --git a/src/crypto.cpp b/src/crypto.cpp index c1ef88a..5277b86 100644 --- a/src/crypto.cpp +++ b/src/crypto.cpp @@ -19,7 +19,8 @@ namespace { static const std::uint8_t CURVE25519_BASEPOINT[32] = {9}; static const std::size_t AES_BLOCK_LENGTH = 16; -static const std::size_t SHA256_BLOCK_LENGTH = 32; +static const std::size_t SHA256_HASH_LENGTH = 32; +static const std::size_t SHA256_BLOCK_LENGTH = 64; static const std::uint8_t HKDF_DEFAULT_SALT[32] = {}; template @@ -37,13 +38,13 @@ inline static void hmac_sha256_key( std::uint8_t const * input_key, std::size_t input_key_length, std::uint8_t * hmac_key ) { + std::memset(hmac_key, 0, SHA256_BLOCK_LENGTH); if (input_key_length > SHA256_BLOCK_LENGTH) { ::SHA256_CTX context; ::sha256_init(&context); ::sha256_update(&context, input_key, input_key_length); ::sha256_final(&context, hmac_key); } else { - std::memset(hmac_key, 0, SHA256_BLOCK_LENGTH); std::memcpy(hmac_key, input_key, input_key_length); } } @@ -56,7 +57,7 @@ inline void hmac_sha256_init( std::uint8_t i_pad[SHA256_BLOCK_LENGTH]; std::memcpy(i_pad, hmac_key, SHA256_BLOCK_LENGTH); for (std::size_t i = 0; i < SHA256_BLOCK_LENGTH; ++i) { - i_pad[i] ^= 0x5C; + i_pad[i] ^= 0x36; } ::sha256_init(context); ::sha256_update(context, i_pad, SHA256_BLOCK_LENGTH); @@ -69,16 +70,15 @@ inline void hmac_sha256_final( std::uint8_t const * hmac_key, std::uint8_t * output ) { - std::uint8_t o_pad[SHA256_BLOCK_LENGTH]; + std::uint8_t o_pad[SHA256_BLOCK_LENGTH + SHA256_HASH_LENGTH]; std::memcpy(o_pad, hmac_key, SHA256_BLOCK_LENGTH); for (std::size_t i = 0; i < SHA256_BLOCK_LENGTH; ++i) { - o_pad[i] ^= 0x36; + o_pad[i] ^= 0x5C; } + ::sha256_final(context, o_pad + SHA256_BLOCK_LENGTH); ::SHA256_CTX final_context; ::sha256_init(&final_context); - ::sha256_update(&final_context, o_pad, SHA256_BLOCK_LENGTH); - ::sha256_final(context, o_pad); - ::sha256_update(&final_context, o_pad, SHA256_BLOCK_LENGTH); + ::sha256_update(&final_context, o_pad, sizeof(o_pad)); ::sha256_final(&final_context, output); std::memset(o_pad, 0, sizeof(o_pad)); } @@ -167,6 +167,16 @@ void axolotl::aes_decrypt_cbc( } +void axolotl::sha256( + std::uint8_t const * input, std::size_t input_length, + std::uint8_t * output +) { + ::SHA256_CTX context; + ::sha256_init(&context); + ::sha256_update(&context, input, input_length); + ::sha256_final(&context, output); +} + void axolotl::hmac_sha256( std::uint8_t const * key, std::size_t key_length, std::uint8_t const * input, std::size_t input_length, @@ -184,14 +194,13 @@ void axolotl::hmac_sha256( void axolotl::hkdf_sha256( std::uint8_t const * input, std::size_t input_length, - std::uint8_t const * info, std::size_t info_length, std::uint8_t const * salt, std::size_t salt_length, + std::uint8_t const * info, std::size_t info_length, std::uint8_t * output, std::size_t output_length ) { ::SHA256_CTX context; - std::uint8_t extract_key[SHA256_BLOCK_LENGTH]; - std::uint8_t expand_key[SHA256_BLOCK_LENGTH]; - std::uint8_t step_result[SHA256_BLOCK_LENGTH]; + std::uint8_t hmac_key[SHA256_BLOCK_LENGTH]; + std::uint8_t step_result[SHA256_HASH_LENGTH]; std::size_t bytes_remaining = output_length; std::uint8_t iteration = 1; if (!salt) { @@ -199,25 +208,27 @@ void axolotl::hkdf_sha256( salt_length = sizeof(HKDF_DEFAULT_SALT); } /* Expand */ - hmac_sha256_key(salt, salt_length, extract_key); - hmac_sha256_init(&context, extract_key); + hmac_sha256_key(salt, salt_length, hmac_key); + hmac_sha256_init(&context, hmac_key); ::sha256_update(&context, input, input_length); - hmac_sha256_final(&context, extract_key, expand_key); + hmac_sha256_final(&context, hmac_key, step_result); + hmac_sha256_key(step_result, SHA256_HASH_LENGTH, hmac_key); + /* Extract */ - hmac_sha256_init(&context, expand_key); + hmac_sha256_init(&context, hmac_key); ::sha256_update(&context, info, info_length); ::sha256_update(&context, &iteration, 1); - hmac_sha256_final(&context, expand_key, step_result); - while (bytes_remaining > SHA256_BLOCK_LENGTH) { - std::memcpy(output, step_result, SHA256_BLOCK_LENGTH); - output += SHA256_BLOCK_LENGTH; - bytes_remaining -= SHA256_BLOCK_LENGTH; + hmac_sha256_final(&context, hmac_key, step_result); + while (bytes_remaining > SHA256_HASH_LENGTH) { + std::memcpy(output, step_result, SHA256_HASH_LENGTH); + output += SHA256_HASH_LENGTH; + bytes_remaining -= SHA256_HASH_LENGTH; iteration ++; - hmac_sha256_init(&context, expand_key); - ::sha256_update(&context, step_result, SHA256_BLOCK_LENGTH); + hmac_sha256_init(&context, hmac_key); + ::sha256_update(&context, step_result, SHA256_HASH_LENGTH); ::sha256_update(&context, info, info_length); ::sha256_update(&context, &iteration, 1); - hmac_sha256_final(&context, expand_key, step_result); + hmac_sha256_final(&context, hmac_key, step_result); } std::memcpy(output, step_result, bytes_remaining); } diff --git a/tests/test_crypto.cpp b/tests/test_crypto.cpp index ed50905..d6e282f 100644 --- a/tests/test_crypto.cpp +++ b/tests/test_crypto.cpp @@ -36,7 +36,137 @@ void assert_equals( int main() { +{ /* Curve25529 Test Case 1 */ +TEST_CASE = "Curve25529 Test Case 1"; + +std::uint8_t alice_private[32] = { + 0x77, 0x07, 0x6D, 0x0A, 0x73, 0x18, 0xA5, 0x7D, + 0x3C, 0x16, 0xC1, 0x72, 0x51, 0xB2, 0x66, 0x45, + 0xDF, 0x4C, 0x2F, 0x87, 0xEB, 0xC0, 0x99, 0x2A, + 0xB1, 0x77, 0xFB, 0xA5, 0x1D, 0xB9, 0x2C, 0x2A +}; + +std::uint8_t alice_public[32] = { + 0x85, 0x20, 0xF0, 0x09, 0x89, 0x30, 0xA7, 0x54, + 0x74, 0x8B, 0x7D, 0xDC, 0xB4, 0x3E, 0xF7, 0x5A, + 0x0D, 0xBF, 0x3A, 0x0D, 0x26, 0x38, 0x1A, 0xF4, + 0xEB, 0xA4, 0xA9, 0x8E, 0xAA, 0x9B, 0x4E, 0x6A +}; + +std::uint8_t bob_private[32] = { + 0x5D, 0xAB, 0x08, 0x7E, 0x62, 0x4A, 0x8A, 0x4B, + 0x79, 0xE1, 0x7F, 0x8B, 0x83, 0x80, 0x0E, 0xE6, + 0x6F, 0x3B, 0xB1, 0x29, 0x26, 0x18, 0xB6, 0xFD, + 0x1C, 0x2F, 0x8B, 0x27, 0xFF, 0x88, 0xE0, 0xEB +}; + +std::uint8_t bob_public[32] = { + 0xDE, 0x9E, 0xDB, 0x7D, 0x7B, 0x7D, 0xC1, 0xB4, + 0xD3, 0x5B, 0x61, 0xC2, 0xEC, 0xE4, 0x35, 0x37, + 0x3F, 0x83, 0x43, 0xC8, 0x5B, 0x78, 0x67, 0x4D, + 0xAD, 0xFC, 0x7E, 0x14, 0x6F, 0x88, 0x2B, 0x4F +}; + +std::uint8_t expected_agreement[32] = { + 0x4A, 0x5D, 0x9D, 0x5B, 0xA4, 0xCE, 0x2D, 0xE1, + 0x72, 0x8E, 0x3B, 0xF4, 0x80, 0x35, 0x0F, 0x25, + 0xE0, 0x7E, 0x21, 0xC9, 0x47, 0xD1, 0x9E, 0x33, + 0x76, 0xF0, 0x9B, 0x3C, 0x1E, 0x16, 0x17, 0x42 +}; + +axolotl::Curve25519KeyPair alice_pair = axolotl::generate_key(alice_private); + +assert_equals(alice_private, alice_pair.private_key, 32); +assert_equals(alice_public, alice_pair.public_key, 32); + +axolotl::Curve25519KeyPair bob_pair = axolotl::generate_key(bob_private); + +assert_equals(bob_private, bob_pair.private_key, 32); +assert_equals(bob_public, bob_pair.public_key, 32); + +std::uint8_t actual_agreement[axolotl::CURVE25519_SHARED_SECRET_LENGTH] = {}; + +axolotl::curve25519_shared_secret(alice_pair, bob_pair, actual_agreement); + +assert_equals(expected_agreement, actual_agreement, 32); + +axolotl::curve25519_shared_secret(bob_pair, alice_pair, actual_agreement); + +assert_equals(expected_agreement, actual_agreement, 32); + +} /* Curve25529 Test Case 1 */ + + +{ /* AES Test Case 1 */ + +TEST_CASE = "AES Test Case 1"; + +axolotl::Aes256Key key = {}; +axolotl::Aes256Iv iv = {}; +std::uint8_t input[32] = {}; + +std::uint8_t expected[32] = { + 0xDC, 0x95, 0xC0, 0x78, 0xA2, 0x40, 0x89, 0x89, + 0xAD, 0x48, 0xA2, 0x14, 0x92, 0x84, 0x20, 0x87, + 0x08, 0xC3, 0x74, 0x84, 0x8C, 0x22, 0x82, 0x33, + 0xC2, 0xB3, 0x4F, 0x33, 0x2B, 0xD2, 0xE9, 0xD3 +}; + +std::uint8_t actual[32] = {}; + +axolotl::aes_encrypt_cbc(key, iv, input, sizeof(input), actual); + +assert_equals(expected, actual, 32); + +axolotl::aes_decrypt_cbc(key, iv, expected, sizeof(expected), actual); + +assert_equals(input, actual, 32); + +} /* AES Test Case 1 */ + + +{ /* SHA 256 Test Case 1 */ + +TEST_CASE = "SHA 256 Test Case 1"; + +std::uint8_t input[0] = {}; + +std::uint8_t expected[32] = { + 0xE3, 0xB0, 0xC4, 0x42, 0x98, 0xFC, 0x1C, 0x14, + 0x9A, 0xFB, 0xF4, 0xC8, 0x99, 0x6F, 0xB9, 0x24, + 0x27, 0xAE, 0x41, 0xE4, 0x64, 0x9B, 0x93, 0x4C, + 0xA4, 0x95, 0x99, 0x1B, 0x78, 0x52, 0xB8, 0x55 +}; + +std::uint8_t actual[32]; + +axolotl::sha256(input, sizeof(input), actual); + +assert_equals(expected, actual, 32); + +} /* SHA 256 Test Case 1 */ + +{ /* HMAC Test Case 1 */ + +TEST_CASE = "HMAC Test Case 1"; + +std::uint8_t input[0] = {}; + +std::uint8_t expected[32] = { + 0xb6, 0x13, 0x67, 0x9a, 0x08, 0x14, 0xd9, 0xec, + 0x77, 0x2f, 0x95, 0xd7, 0x78, 0xc3, 0x5f, 0xc5, + 0xff, 0x16, 0x97, 0xc4, 0x93, 0x71, 0x56, 0x53, + 0xc6, 0xc7, 0x12, 0x14, 0x42, 0x92, 0xc5, 0xad +}; + +std::uint8_t actual[32]; + +axolotl::hmac_sha256(input, sizeof(input), input, sizeof(input), actual); + +assert_equals(expected, actual, 32); + +} /* HMAC Test Case 1 */ { /* HDKF Test Case 1 */ @@ -68,8 +198,8 @@ std::uint8_t hmac_expected_output[32] = { std::uint8_t hmac_actual_output[32] = {}; axolotl::hmac_sha256( - salt, 0 * sizeof(salt), - input, 0 * sizeof(input), + salt, sizeof(salt), + input, sizeof(input), hmac_actual_output );