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/* 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 "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;
}
int hmac_drbg_generate(struct drbg_ctx *ctx,
void *out, size_t out_len,
const void *input, size_t input_len)
{
/* TODO(louiscollard): Assert maximum output length? */
if (ctx->reseed_counter >= 10000)
return 2;
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);
ctx->reseed_counter++;
return 0;
}
void hmac_drbg_generate_p256(struct drbg_ctx *ctx, p256_int *k_out)
{
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);
#endif /* CRYPTO_TEST_SETUP */
|