diff options
Diffstat (limited to 'board/cr50/dcrypto/hmac_drbg.c')
-rw-r--r-- | board/cr50/dcrypto/hmac_drbg.c | 478 |
1 files changed, 478 insertions, 0 deletions
diff --git a/board/cr50/dcrypto/hmac_drbg.c b/board/cr50/dcrypto/hmac_drbg.c new file mode 100644 index 0000000000..2ca20e03ff --- /dev/null +++ b/board/cr50/dcrypto/hmac_drbg.c @@ -0,0 +1,478 @@ +/* Copyright 2018 The Chromium OS Authors. All rights reserved. + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +#include "console.h" +#include "cryptoc/util.h" +#include "dcrypto.h" +#include "extension.h" +#include "internal.h" +#include "trng.h" + +/* HMAC_DRBG flow in NIST SP 800-90Ar1, 10.2, RFC 6979 + */ +/* V = HMAC(K, V) */ +static void update_v(const uint32_t *k, uint32_t *v) +{ + LITE_HMAC_CTX ctx; + + DCRYPTO_HMAC_SHA256_init(&ctx, k, SHA256_DIGEST_SIZE); + HASH_update(&ctx.hash, v, SHA256_DIGEST_SIZE); + memcpy(v, DCRYPTO_HMAC_final(&ctx), SHA256_DIGEST_SIZE); +} + +/* K = HMAC(K, V || tag || p0 || p1 || p2) */ +/* V = HMAC(K, V) */ +static void update_kv(uint32_t *k, uint32_t *v, uint8_t tag, + const void *p0, size_t p0_len, + const void *p1, size_t p1_len, + const void *p2, size_t p2_len) +{ + LITE_HMAC_CTX ctx; + + DCRYPTO_HMAC_SHA256_init(&ctx, k, SHA256_DIGEST_SIZE); + HASH_update(&ctx.hash, v, SHA256_DIGEST_SIZE); + HASH_update(&ctx.hash, &tag, 1); + HASH_update(&ctx.hash, p0, p0_len); + HASH_update(&ctx.hash, p1, p1_len); + HASH_update(&ctx.hash, p2, p2_len); + memcpy(k, DCRYPTO_HMAC_final(&ctx), SHA256_DIGEST_SIZE); + + update_v(k, v); +} + +static void update(struct drbg_ctx *ctx, + const void *p0, size_t p0_len, + const void *p1, size_t p1_len, + const void *p2, size_t p2_len) +{ + /* K = HMAC(K, V || 0x00 || provided_data) */ + /* V = HMAC(K, V) */ + update_kv(ctx->k, ctx->v, 0x00, + p0, p0_len, p1, p1_len, p2, p2_len); + + /* If no provided_data, stop. */ + if (p0_len + p1_len + p2_len == 0) + return; + + /* K = HMAC(K, V || 0x01 || provided_data) */ + /* V = HMAC(K, V) */ + update_kv(ctx->k, ctx->v, + 0x01, + p0, p0_len, p1, p1_len, p2, p2_len); +} + +void hmac_drbg_init(struct drbg_ctx *ctx, + const void *p0, size_t p0_len, + const void *p1, size_t p1_len, + const void *p2, size_t p2_len) +{ + /* K = 0x00 0x00 0x00 ... 0x00 */ + always_memset(ctx->k, 0x00, sizeof(ctx->k)); + /* V = 0x01 0x01 0x01 ... 0x01 */ + always_memset(ctx->v, 0x01, sizeof(ctx->v)); + + update(ctx, p0, p0_len, p1, p1_len, p2, p2_len); + + ctx->reseed_counter = 1; +} + +void hmac_drbg_init_rfc6979(struct drbg_ctx *ctx, const p256_int *key, + const p256_int *message) +{ + hmac_drbg_init(ctx, + key->a, sizeof(key->a), + message->a, sizeof(message->a), + NULL, 0); +} + +void hmac_drbg_init_rand(struct drbg_ctx *ctx, size_t nbits) +{ + int i; + uint32_t x[(nbits + 31) / 32]; + + for (i = 0; i < ARRAY_SIZE(x); ++i) + x[i] = rand(); + + hmac_drbg_init(ctx, &x, sizeof(x), NULL, 0, NULL, 0); +} + +void hmac_drbg_reseed(struct drbg_ctx *ctx, + const void *p0, size_t p0_len, + const void *p1, size_t p1_len, + const void *p2, size_t p2_len) +{ + update(ctx, p0, p0_len, p1, p1_len, p2, p2_len); + ctx->reseed_counter = 1; +} + +enum hmac_result hmac_drbg_generate(struct drbg_ctx *ctx, + void *out, size_t out_len, + const void *input, size_t input_len) +{ + /* According to NIST SP 800-90A rev 1 B.2 + * Maximum number of bits per request = 7500 bits + * Reseed_interval = 10 000 requests. + */ + if (out_len > 7500 / 8) + return HMAC_DRBG_INVALID_PARAM; + + if (ctx->reseed_counter++ >= 10000) + return HMAC_DRBG_RESEED_REQUIRED; + + if (input_len) + update(ctx, input, input_len, NULL, 0, NULL, 0); + + while (out_len) { + size_t n = out_len > sizeof(ctx->v) ? sizeof(ctx->v) : out_len; + + update_v(ctx->k, ctx->v); + + memcpy(out, ctx->v, n); + out += n; + out_len -= n; + } + + update(ctx, input, input_len, NULL, 0, NULL, 0); + + return HMAC_DRBG_SUCCESS; +} + +enum hmac_result hmac_drbg_generate_p256(struct drbg_ctx *ctx, p256_int *k_out) +{ + return hmac_drbg_generate(ctx, k_out->a, sizeof(k_out->a), NULL, 0); +} + +void drbg_exit(struct drbg_ctx *ctx) +{ + always_memset(ctx->k, 0x00, sizeof(ctx->k)); + always_memset(ctx->v, 0x00, sizeof(ctx->v)); +} + +#ifdef CRYPTO_TEST_SETUP + +/* + * from the RFC 6979 A.2.5 example: + * + * curve: NIST P-256 + * + * q = FFFFFFFF00000000FFFFFFFFFFFFFFFFBCE6FAADA7179E84F3B9CAC2FC632551 + * (qlen = 256 bits) + * + * private key: + * x = C9AFA9D845BA75166B5C215767B1D6934E50C3DB36E89B127B8A622B120F6721 + * + * public key: U = xG + * Ux = 60FED4BA255A9D31C961EB74C6356D68C049B8923B61FA6CE669622E60F29FB6 + * Uy = 7903FE1008B8BC99A41AE9E95628BC64F2F1B20C2D7E9F5177A3C294D4462299 + * + * Signature: + * With SHA-256, message = "sample": + * k = A6E3C57DD01ABE90086538398355DD4C3B17AA873382B0F24D6129493D8AAD60 + * r = EFD48B2AACB6A8FD1140DD9CD45E81D69D2C877B56AAF991C34D0EA84EAF3716 + * s = F7CB1C942D657C41D436C7A1B6E29F65F3E900DBB9AFF4064DC4AB2F843ACDA8 + */ +static int cmd_rfc6979(int argc, char **argv) +{ + static p256_int h1; + static p256_int k; + static const char message[] = "sample"; + static struct drbg_ctx drbg; + + static HASH_CTX ctx; + int result; + static const uint8_t priv_from_rfc[] = { + 0xC9, 0xAF, 0xA9, 0xD8, 0x45, 0xBA, 0x75, 0x16, + 0x6B, 0x5C, 0x21, 0x57, 0x67, 0xB1, 0xD6, 0x93, + 0x4E, 0x50, 0xC3, 0xDB, 0x36, 0xE8, 0x9B, 0x12, + 0x7B, 0x8A, 0x62, 0x2B, 0x12, 0x0F, 0x67, 0x21 + }; + static const uint8_t k_from_rfc[] = { + 0xA6, 0xE3, 0xC5, 0x7D, 0xD0, 0x1A, 0xBE, 0x90, + 0x08, 0x65, 0x38, 0x39, 0x83, 0x55, 0xDD, 0x4C, + 0x3B, 0x17, 0xAA, 0x87, 0x33, 0x82, 0xB0, 0xF2, + 0x4D, 0x61, 0x29, 0x49, 0x3D, 0x8A, 0xAD, 0x60 + }; + p256_int *x = (p256_int *)priv_from_rfc; + p256_int *reference_k = (p256_int *)k_from_rfc; + + /* h1 = H(m) */ + DCRYPTO_SHA256_init(&ctx, 1); + HASH_update(&ctx, message, sizeof(message) - 1); + memcpy(&h1, HASH_final(&ctx), SHA256_DIGEST_SIZE); + + hmac_drbg_init_rfc6979(&drbg, x, &h1); + do { + hmac_drbg_generate_p256(&drbg, &k); + ccprintf("K = %ph\n", HEX_BUF(&k, 32)); + } while (p256_cmp(&SECP256r1_nMin2, &k) < 0); + drbg_exit(&drbg); + result = p256_cmp(&k, reference_k); + ccprintf("K generation: %s\n", result ? "FAIL" : "PASS"); + + return result ? EC_ERROR_INVAL : EC_SUCCESS; +} +DECLARE_SAFE_CONSOLE_COMMAND(rfc6979, cmd_rfc6979, NULL, NULL); + +/* + * Test vectors from the NIST Cryptographic Algorithm Validation Program. + * + * These are the first two examples from the SHA-256, without prediction + * resistance, and with reseed supported. + */ +#define HMAC_TEST_COUNT 2 +static int cmd_hmac_drbg(int argc, char **argv) +{ + static struct drbg_ctx ctx; + + static const uint8_t init_entropy[HMAC_TEST_COUNT][32] = { + { + 0x06, 0x03, 0x2C, 0xD5, 0xEE, 0xD3, 0x3F, 0x39, 0x26, + 0x5F, 0x49, 0xEC, 0xB1, 0x42, 0xC5, 0x11, 0xDA, 0x9A, + 0xFF, 0x2A, 0xF7, 0x12, 0x03, 0xBF, 0xFA, 0xF3, 0x4A, + 0x9C, 0xA5, 0xBD, 0x9C, 0x0D + }, + { + 0xAA, 0xDC, 0xF3, 0x37, 0x78, 0x8B, 0xB8, 0xAC, 0x01, + 0x97, 0x66, 0x40, 0x72, 0x6B, 0xC5, 0x16, 0x35, 0xD4, + 0x17, 0x77, 0x7F, 0xE6, 0x93, 0x9E, 0xDE, 0xD9, 0xCC, + 0xC8, 0xA3, 0x78, 0xC7, 0x6A + }, + }; + + static const uint8_t init_nonce[HMAC_TEST_COUNT][16] = { + { + 0x0E, 0x66, 0xF7, 0x1E, 0xDC, 0x43, 0xE4, 0x2A, 0x45, + 0xAD, 0x3C, 0x6F, 0xC6, 0xCD, 0xC4, 0xDF + }, + { + 0x9C, 0xCC, 0x9D, 0x80, 0xC8, 0x9A, 0xC5, 0x5A, 0x8C, + 0xFE, 0x0F, 0x99, 0x94, 0x2F, 0x5A, 0x4D + }, + }; + + static const uint8_t reseed_entropy[HMAC_TEST_COUNT][32] = { + { + 0x01, 0x92, 0x0A, 0x4E, 0x66, 0x9E, 0xD3, 0xA8, 0x5A, + 0xE8, 0xA3, 0x3B, 0x35, 0xA7, 0x4A, 0xD7, 0xFB, 0x2A, + 0x6B, 0xB4, 0xCF, 0x39, 0x5C, 0xE0, 0x03, 0x34, 0xA9, + 0xC9, 0xA5, 0xA5, 0xD5, 0x52 + }, + { + 0x03, 0xA5, 0x77, 0x92, 0x54, 0x7E, 0x0C, 0x98, 0xEA, + 0x17, 0x76, 0xE4, 0xBA, 0x80, 0xC0, 0x07, 0x34, 0x62, + 0x96, 0xA5, 0x6A, 0x27, 0x0A, 0x35, 0xFD, 0x9E, 0xA2, + 0x84, 0x5C, 0x7E, 0x81, 0xE2 + } + }; + + static const uint8_t expected_output[HMAC_TEST_COUNT][128] = { + { + 0x76, 0xFC, 0x79, 0xFE, 0x9B, 0x50, 0xBE, 0xCC, 0xC9, + 0x91, 0xA1, 0x1B, 0x56, 0x35, 0x78, 0x3A, 0x83, 0x53, + 0x6A, 0xDD, 0x03, 0xC1, 0x57, 0xFB, 0x30, 0x64, 0x5E, + 0x61, 0x1C, 0x28, 0x98, 0xBB, 0x2B, 0x1B, 0xC2, 0x15, + 0x00, 0x02, 0x09, 0x20, 0x8C, 0xD5, 0x06, 0xCB, 0x28, + 0xDA, 0x2A, 0x51, 0xBD, 0xB0, 0x38, 0x26, 0xAA, 0xF2, + 0xBD, 0x23, 0x35, 0xD5, 0x76, 0xD5, 0x19, 0x16, 0x08, + 0x42, 0xE7, 0x15, 0x8A, 0xD0, 0x94, 0x9D, 0x1A, 0x9E, + 0xC3, 0xE6, 0x6E, 0xA1, 0xB1, 0xA0, 0x64, 0xB0, 0x05, + 0xDE, 0x91, 0x4E, 0xAC, 0x2E, 0x9D, 0x4F, 0x2D, 0x72, + 0xA8, 0x61, 0x6A, 0x80, 0x22, 0x54, 0x22, 0x91, 0x82, + 0x50, 0xFF, 0x66, 0xA4, 0x1B, 0xD2, 0xF8, 0x64, 0xA6, + 0xA3, 0x8C, 0xC5, 0xB6, 0x49, 0x9D, 0xC4, 0x3F, 0x7F, + 0x2B, 0xD0, 0x9E, 0x1E, 0x0F, 0x8F, 0x58, 0x85, 0x93, + 0x51, 0x24 + }, + { + 0x17, 0xD0, 0x9F, 0x40, 0xA4, 0x37, 0x71, 0xF4, 0xA2, + 0xF0, 0xDB, 0x32, 0x7D, 0xF6, 0x37, 0xDE, 0xA9, 0x72, + 0xBF, 0xFF, 0x30, 0xC9, 0x8E, 0xBC, 0x88, 0x42, 0xDC, + 0x7A, 0x9E, 0x3D, 0x68, 0x1C, 0x61, 0x90, 0x2F, 0x71, + 0xBF, 0xFA, 0xF5, 0x09, 0x36, 0x07, 0xFB, 0xFB, 0xA9, + 0x67, 0x4A, 0x70, 0xD0, 0x48, 0xE5, 0x62, 0xEE, 0x88, + 0xF0, 0x27, 0xF6, 0x30, 0xA7, 0x85, 0x22, 0xEC, 0x6F, + 0x70, 0x6B, 0xB4, 0x4A, 0xE1, 0x30, 0xE0, 0x5C, 0x8D, + 0x7E, 0xAC, 0x66, 0x8B, 0xF6, 0x98, 0x0D, 0x99, 0xB4, + 0xC0, 0x24, 0x29, 0x46, 0x45, 0x23, 0x99, 0xCB, 0x03, + 0x2C, 0xC6, 0xF9, 0xFD, 0x96, 0x28, 0x47, 0x09, 0xBD, + 0x2F, 0xA5, 0x65, 0xB9, 0xEB, 0x9F, 0x20, 0x04, 0xBE, + 0x6C, 0x9E, 0xA9, 0xFF, 0x91, 0x28, 0xC3, 0xF9, 0x3B, + 0x60, 0xDC, 0x30, 0xC5, 0xFC, 0x85, 0x87, 0xA1, 0x0D, + 0xE6, 0x8C + } + }; + + static uint8_t output[128]; + + int i, cmp_result; + + for (i = 0; i < HMAC_TEST_COUNT; i++) { + hmac_drbg_init(&ctx, + init_entropy[i], sizeof(init_entropy[i]), + init_nonce[i], sizeof(init_nonce[i]), + NULL, 0); + + hmac_drbg_reseed(&ctx, + reseed_entropy[i], sizeof(reseed_entropy[i]), + NULL, 0, + NULL, 0); + + hmac_drbg_generate(&ctx, + output, sizeof(output), + NULL, 0); + + hmac_drbg_generate(&ctx, + output, sizeof(output), + NULL, 0); + + cmp_result = memcmp(output, expected_output[i], sizeof(output)); + ccprintf("HMAC DRBG generate test %d, %s\n", + i, cmp_result ? "failed" : "passed"); + } + + return 0; +} +DECLARE_SAFE_CONSOLE_COMMAND(hmac_drbg, cmd_hmac_drbg, NULL, NULL); + +/* + * Sanity check to exercise random initialization. + */ +static int cmd_hmac_drbg_rand(int argc, char **argv) +{ + static struct drbg_ctx ctx; + static uint8_t output[128]; + + int i; + + hmac_drbg_init_rand(&ctx, 256); + + hmac_drbg_generate(&ctx, output, sizeof(output), NULL, 0); + + ccprintf("Randomly initialized HMAC DRBG, 1024 bit output: "); + + for (i = 0; i < sizeof(output); i++) + ccprintf("%x", output[i]); + ccprintf("\n"); + + return 0; +} +DECLARE_SAFE_CONSOLE_COMMAND(hmac_drbg_rand, cmd_hmac_drbg_rand, NULL, NULL); + +enum drbg_command { + DRBG_INIT = 0, + DRBG_RESEED = 1, + DRBG_GENERATE = 2 +}; + +/* + * DRBG_TEST command structure: + * + * field | size | note + * ========================================================================== + * mode | 1 | 0 - DRBG_INIT, 1 - DRBG_RESEED, 2 - DRBG_GENERATE + * p0_len | 2 | size of first input in bytes + * p0 | p0_len | entropy for INIT & SEED, input for GENERATE + * p1_len | 2 | size of second input in bytes (for INIT & RESEED) + * | | or size of expected output for GENERATE + * p1 | p1_len | nonce for INIT & SEED + * p2_len | 2 | size of third input in bytes for DRBG_INIT + * p2 | p2_len | personalization for INIT & SEED + * + * DRBG_INIT (entropy, nonce, perso) + * DRBG_RESEED (entropy, additional input 1, additional input 2) + * DRBG_INIT and DRBG_RESEED returns empty response + * DRBG_GENERATE (p0_len, p0 - additional input 1, p1_len - size of output) + * DRBG_GENERATE returns p1_len bytes of generated data + * (up to a maximum of 128 bytes) + */ +static enum vendor_cmd_rc drbg_test(enum vendor_cmd_cc code, void *buf, + size_t input_size, size_t *response_size) +{ + static struct drbg_ctx drbg_ctx; + static uint8_t output[512]; + uint8_t *p0 = NULL, *p1 = NULL, *p2 = NULL; + uint16_t p0_len = 0, p1_len = 0, p2_len = 0; + uint8_t *cmd = (uint8_t *)buf; + size_t max_out_len = *response_size; + enum drbg_command drbg_op; + + *response_size = 0; + /* there is always op + first parameter, even if zero length */ + if (input_size < sizeof(p0_len) + 1) + return VENDOR_RC_BOGUS_ARGS; + drbg_op = *cmd++; + p0_len = *cmd++; + p0_len = p0_len * 256 + *cmd++; + input_size -= 3; + if (p0_len > input_size) + return VENDOR_RC_BOGUS_ARGS; + input_size -= p0_len; + if (p0_len) + p0 = cmd; + cmd += p0_len; + + /* there should be enough space for p1_len */ + if (input_size && input_size < sizeof(p1_len)) + return VENDOR_RC_BOGUS_ARGS; + + /* DRBG_GENERATE should just have p1_len defined */ + if (drbg_op == DRBG_GENERATE && input_size != sizeof(p1_len)) + return VENDOR_RC_BOGUS_ARGS; + + if (input_size) { + p1_len = *cmd++; + p1_len = p1_len * 256 + *cmd++; + input_size -= 2; + + if (drbg_op != DRBG_GENERATE) { + if (p1_len > input_size) + return VENDOR_RC_BOGUS_ARGS; + input_size -= p1_len; + if (p1_len) + p1 = cmd; + cmd += p1_len; + } + } + + if (input_size) { + if (drbg_op == DRBG_GENERATE) + return VENDOR_RC_BOGUS_ARGS; + p2_len = *cmd++; + p2_len = p2_len * 256 + *cmd++; + input_size -= 2; + if (p2_len > input_size) + return VENDOR_RC_BOGUS_ARGS; + if (p2_len) + p2 = cmd; + } + + switch (drbg_op) { + case DRBG_INIT: { + hmac_drbg_init(&drbg_ctx, p0, p0_len, p1, p1_len, p2, p2_len); + break; + } + case DRBG_RESEED: { + hmac_drbg_reseed(&drbg_ctx, p0, p0_len, p1, p1_len, p2, p2_len); + break; + } + case DRBG_GENERATE: { + if (p1_len > sizeof(output) || max_out_len < p1_len) + return VENDOR_RC_BOGUS_ARGS; + + hmac_drbg_generate(&drbg_ctx, output, p1_len, p0, p0_len); + + memcpy(buf, output, p1_len); + *response_size = p1_len; + break; + } + default: + return VENDOR_RC_BOGUS_ARGS; + } + + return VENDOR_RC_SUCCESS; +} +DECLARE_VENDOR_COMMAND(VENDOR_CC_DRBG_TEST, drbg_test); + +#endif /* CRYPTO_TEST_SETUP */ |