diff --git a/sys/hashes/cmac.c b/sys/hashes/cmac.c new file mode 100644 index 0000000000000000000000000000000000000000..698d0925d7b5e6555162331742c2680dfdf9e6ff --- /dev/null +++ b/sys/hashes/cmac.c @@ -0,0 +1,113 @@ +/* + * Copyright (C) 2016 Fundación Inria Chile + * + * This file is subject to the terms and conditions of the GNU Lesser + * General Public License v2.1. See the file LICENSE in the top level + * directory for more details. + */ + +/** + * @ingroup sys_hashes_cmac + * @{ + * + * @file + * @brief AES_CMAC implementation + * + * @author José Ignacio Alamos <jose.alamos@inria.cl> + * + * @} + */ + +#include <inttypes.h> +#include <stdio.h> +#include <string.h> + +#include "crypto/ciphers.h" +#include "hashes/cmac.h" + +#define MIN(a, b) a < b ? a : b + +static void _xor128(uint8_t *x, uint8_t *y) +{ + for (unsigned i = 0; i < 16; i++) { + y[i] = x[i] ^ y[i]; + } +} + +static void _leftshift(uint8_t *x, uint8_t *y) +{ + for (unsigned i = 0; i < 15; i++) { + y[i] = (x[i] << 1) | (x[i + 1] >> 7); + } + y[15] = x[15] << 1; +} + +int cmac_init(cmac_context_t *ctx, const uint8_t *key, uint8_t key_size) +{ + if (key_size != CMAC_BLOCK_SIZE) { + return CIPHER_ERR_INVALID_KEY_SIZE; + } + + memset(ctx, 0, sizeof(cmac_context_t)); + return cipher_init(&(ctx->aes_ctx), CIPHER_AES_128, key, key_size); +} + +void cmac_update(cmac_context_t *ctx, const void *data, size_t len) +{ + uint8_t d[16]; + + while (len) { + uint8_t c; + if (ctx->M_n == 16) { + ctx->M_n = 0; + _xor128(ctx->M_last, ctx->X); + cipher_encrypt(&ctx->aes_ctx, ctx->X, d); + memcpy(ctx->X, d, CMAC_BLOCK_SIZE); + } + c = MIN(CMAC_BLOCK_SIZE - ctx->M_n, len); + memcpy(ctx->M_last + ctx->M_n, data, c); + ctx->M_n += c; + len -= c; + data = (void *) (((uint8_t *) data) + c); + + if (ctx->M_n < CMAC_BLOCK_SIZE) { + break; + } + } +} + +void cmac_final(cmac_context_t *ctx, void *digest) +{ + /* Generate subkeys */ + uint8_t K[CMAC_BLOCK_SIZE]; + uint8_t L[CMAC_BLOCK_SIZE]; + + memset(K, 0, CMAC_BLOCK_SIZE); + cipher_encrypt(&ctx->aes_ctx, K, L); + + if (L[0] & 0x80) { + _leftshift(L, K); + K[15] ^= 0x87; + } + else { + _leftshift(L, K); + } + + if (ctx->M_n != 16) { + /* Generate K2 */ + if (K[0] & 0x80) { + _leftshift(K, K); + K[15] ^= 0x87; + } + else { + _leftshift(K, K); + } + /* Padding */ + memset(ctx->M_last + ctx->M_n, 0, CMAC_BLOCK_SIZE - ctx->M_n); + ctx->M_last[ctx->M_n] = 0x80; + } + _xor128(K, ctx->M_last); + _xor128(ctx->M_last, ctx->X); + cipher_encrypt(&ctx->aes_ctx, ctx->X, L); + memcpy(digest, L, CMAC_BLOCK_SIZE); +} diff --git a/sys/include/hashes/cmac.h b/sys/include/hashes/cmac.h new file mode 100644 index 0000000000000000000000000000000000000000..dc84b08fe87ba51ce176ae13593ccc60e9fc5b54 --- /dev/null +++ b/sys/include/hashes/cmac.h @@ -0,0 +1,85 @@ +/* + * Copyright (C) 2016 Fundación Inria Chile + * + * This file is subject to the terms and conditions of the GNU Lesser + * General Public License v2.1. See the file LICENSE in the top level + * directory for more details. + */ + +/** + * @defgroup sys_hashes_cmac AES_CMAC + * @ingroup sys_hashes + * @brief Implementation of the AES CMAC hashing function + + * @{ + * + * @file + * @brief AES_CMAC interface definition + * + * @author José Ignacio Alamos <jose.alamos@inria.cl> + */ + +#ifndef HASHES_CMAC_H +#define HASHES_CMAC_H + +#include <stdio.h> +#include "crypto/ciphers.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * @brief Length of AES_CMAC block in bytes + */ +#define CMAC_BLOCK_SIZE 16 + +/** + * @brief AES_CMAC calculation context + */ +typedef struct { + /** AES128 context */ + cipher_t aes_ctx; + /** auxiliar array for CMAC calculations **/ + uint8_t X[CMAC_BLOCK_SIZE]; + /** current last block **/ + uint8_t M_last[CMAC_BLOCK_SIZE]; + /** last byte in last block */ + uint32_t M_n; +} cmac_context_t; + +/** + * @brief Initialize CMAC message digest context + * + * @param[in] ctx Pointer to the CMAC context to initialize + * @param[in] key Key to be set + * @param[in] key_size Size of the key + * + * @return CIPHER_INIT_SUCCESS if the initialization was successful. + * CIPHER_ERR_INVALID_KEY_SIZE if the key size is not valid. + */ +int cmac_init(cmac_context_t *ctx, const uint8_t *key, uint8_t key_size); + +/** + * @brief Update the CMAC context with a portion of the message being hashed + * + * @param[in] ctx Pointer to the CMAC context to update + * @param[in] data Input data + * @param[in] len Length of @p data + */ +void cmac_update(cmac_context_t *ctx, const void *data, size_t len); + +/** + * @brief Finalizes the CMAC message digest + * + * @param[in] ctx Pointer to the CMAC context + * @param[out] digest Result location + */ +void cmac_final(cmac_context_t *ctx, void *digest); + +#ifdef __cplusplus +} +#endif + +#endif /* HASHES_CMAC_H */ +/** @} */ diff --git a/tests/unittests/tests-hashes/Makefile.include b/tests/unittests/tests-hashes/Makefile.include index 2e48f79c72e28bc397d9a83216bc4666a51ab5e5..3e52b3734fe830cca8a1b1e4a131faf4b74e20ee 100644 --- a/tests/unittests/tests-hashes/Makefile.include +++ b/tests/unittests/tests-hashes/Makefile.include @@ -1 +1,3 @@ USEMODULE += hashes +USEMODULE += crypto +CFLAGS += -DCRYPTO_AES diff --git a/tests/unittests/tests-hashes/tests-hashes-cmac.c b/tests/unittests/tests-hashes/tests-hashes-cmac.c new file mode 100644 index 0000000000000000000000000000000000000000..feb3765bfab975c66bf5bd39aa51164530e02274 --- /dev/null +++ b/tests/unittests/tests-hashes/tests-hashes-cmac.c @@ -0,0 +1,115 @@ +/* + * Copyright (C) 2016 Fundación Inria Chile + * + * This file is subject to the terms and conditions of the GNU Lesser + * General Public License v2.1. See the file LICENSE in the top level + * directory for more details. + */ + +/** + * @ingroup unittests + * @{ + * + * @file + * @brief Test cases for the AES-CMAC hash implementation + * + * @author José Ignacio Alamos <jose.alamos@inria.cl> + * + * @} + */ + +#include <inttypes.h> +#include <string.h> + +#include "tests-hashes.h" +#include "embUnit/embUnit.h" +#include "hashes/cmac.h" +#include "crypto/ciphers.h" + +static const uint8_t CMAC_KEY[16] = { + 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, + 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c +}; + +static const uint8_t TEST_EMPTY_EXP[16] = { + 0xbb, 0x1d, 0x69, 0x29, 0xe9, 0x59, 0x37, 0x28, + 0x7f, 0xa3, 0x7d, 0x12, 0x9b, 0x75, 0x67, 0x46 +}; + +static const uint8_t TEST_1_INP[16] = { + 0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, + 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a +}; + +static const uint8_t TEST_1_EXP[16] = { + 0x07, 0x0a, 0x16, 0xb4, 0x6b, 0x4d, 0x41, 0x44, + 0xf7, 0x9b, 0xdd, 0x9d, 0xd0, 0x4a, 0x28, 0x7c +}; + +static const uint8_t TEST_2_INP[40] = { + 0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, + 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a, + 0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, + 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51, + 0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11 +}; + +static const uint8_t TEST_2_EXP[16] = { + 0xdf, 0xa6, 0x67, 0x47, 0xde, 0x9a, 0xe6, 0x30, + 0x30, 0xca, 0x32, 0x61, 0x14, 0x97, 0xc8, 0x27 +}; + +static const uint8_t TEST_3_INP[64] = { + 0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, + 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a, + 0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, + 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51, + 0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, + 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef, + 0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, + 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10 +}; + +static const uint8_t TEST_3_EXP[16] = { + 0x51, 0xf0, 0xbe, 0xbf, 0x7e, 0x3b, 0x9d, 0x92, + 0xfc, 0x49, 0x74, 0x17, 0x79, 0x36, 0x3c, 0xfe +}; + +static int calc_and_compare_hash(const uint8_t *hash, size_t size, const uint8_t *expected) +{ + uint8_t digest[16]; + cmac_context_t ctx; + + cmac_init(&ctx, CMAC_KEY, 16); + cmac_update(&ctx, hash, size); + cmac_final(&ctx, digest); + return memcmp(digest, expected, 16); +} + +static void test_hashes_cmac(void) +{ + TEST_ASSERT_EQUAL_INT(calc_and_compare_hash(NULL, 0, TEST_EMPTY_EXP), 0); + TEST_ASSERT_EQUAL_INT(calc_and_compare_hash(TEST_1_INP, 16, TEST_1_EXP), 0); + TEST_ASSERT_EQUAL_INT(calc_and_compare_hash(TEST_2_INP, 40, TEST_2_EXP), 0); + TEST_ASSERT_EQUAL_INT(calc_and_compare_hash(TEST_3_INP, 64, TEST_3_EXP), 0); +} + +static void test_hashes_cmac_keysize(void) +{ + cmac_context_t ctx; + + TEST_ASSERT_EQUAL_INT(cmac_init(&ctx, CMAC_KEY, 15), CIPHER_ERR_INVALID_KEY_SIZE); + TEST_ASSERT_EQUAL_INT(cmac_init(&ctx, CMAC_KEY, 16), CIPHER_INIT_SUCCESS); +} + +Test *tests_hashes_cmac_tests(void) +{ + EMB_UNIT_TESTFIXTURES(fixtures) { + new_TestFixture(test_hashes_cmac), + new_TestFixture(test_hashes_cmac_keysize), + }; + + EMB_UNIT_TESTCALLER(test_hashes_cmac, NULL, NULL, fixtures); + + return (Test *)&test_hashes_cmac; +} diff --git a/tests/unittests/tests-hashes/tests-hashes.c b/tests/unittests/tests-hashes/tests-hashes.c index c66911e61a2839e98dc0ea3b952a79e0ca5c9f89..aec41907d96b0e8d8ddd2877160741f618dc2f00 100644 --- a/tests/unittests/tests-hashes/tests-hashes.c +++ b/tests/unittests/tests-hashes/tests-hashes.c @@ -23,6 +23,7 @@ void tests_hashes(void) { TESTS_RUN(tests_hashes_md5_tests()); + TESTS_RUN(tests_hashes_cmac_tests()); TESTS_RUN(tests_hashes_sha1_tests()); TESTS_RUN(tests_hashes_sha256_tests()); TESTS_RUN(tests_hashes_sha256_hmac_tests()); diff --git a/tests/unittests/tests-hashes/tests-hashes.h b/tests/unittests/tests-hashes/tests-hashes.h index 3904c01336cd93236e80aa1e1e704fa2574ff02c..3e5a35bdead83f41b3994ac6da55e8efdb5fc874 100644 --- a/tests/unittests/tests-hashes/tests-hashes.h +++ b/tests/unittests/tests-hashes/tests-hashes.h @@ -35,6 +35,13 @@ void tests_hashes(void); * * @return embUnit tests if successful, NULL if not. */ +Test *tests_hashes_cmac_tests(void); + +/** + * @brief Generates tests for hashes/cmac.h + * + * @return embUnit tests if successful, NULL if not. + */ Test *tests_hashes_md5_tests(void); /**