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godot/thirdparty/mbedtls/library/hmac_drbg.c

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/*
* HMAC_DRBG implementation (NIST SP 800-90)
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
*/
/*
* The NIST SP 800-90A DRBGs are described in the following publication.
* http://csrc.nist.gov/publications/nistpubs/800-90A/SP800-90A.pdf
* References below are based on rev. 1 (January 2012).
*/
#include "common.h"
#if defined(MBEDTLS_HMAC_DRBG_C)
#include "mbedtls/hmac_drbg.h"
#include "mbedtls/platform_util.h"
#include "mbedtls/error.h"
#include <string.h>
#if defined(MBEDTLS_FS_IO)
#include <stdio.h>
#endif
#include "mbedtls/platform.h"
/*
* HMAC_DRBG context initialization
*/
void mbedtls_hmac_drbg_init(mbedtls_hmac_drbg_context *ctx)
{
memset(ctx, 0, sizeof(mbedtls_hmac_drbg_context));
ctx->reseed_interval = MBEDTLS_HMAC_DRBG_RESEED_INTERVAL;
}
/*
* HMAC_DRBG update, using optional additional data (10.1.2.2)
*/
int mbedtls_hmac_drbg_update(mbedtls_hmac_drbg_context *ctx,
const unsigned char *additional,
size_t add_len)
{
size_t md_len = mbedtls_md_get_size(ctx->md_ctx.md_info);
unsigned char rounds = (additional != NULL && add_len != 0) ? 2 : 1;
unsigned char sep[1];
unsigned char K[MBEDTLS_MD_MAX_SIZE];
int ret = MBEDTLS_ERR_MD_BAD_INPUT_DATA;
for (sep[0] = 0; sep[0] < rounds; sep[0]++) {
/* Step 1 or 4 */
if ((ret = mbedtls_md_hmac_reset(&ctx->md_ctx)) != 0) {
goto exit;
}
if ((ret = mbedtls_md_hmac_update(&ctx->md_ctx,
ctx->V, md_len)) != 0) {
goto exit;
}
if ((ret = mbedtls_md_hmac_update(&ctx->md_ctx,
sep, 1)) != 0) {
goto exit;
}
if (rounds == 2) {
if ((ret = mbedtls_md_hmac_update(&ctx->md_ctx,
additional, add_len)) != 0) {
goto exit;
}
}
if ((ret = mbedtls_md_hmac_finish(&ctx->md_ctx, K)) != 0) {
goto exit;
}
/* Step 2 or 5 */
if ((ret = mbedtls_md_hmac_starts(&ctx->md_ctx, K, md_len)) != 0) {
goto exit;
}
if ((ret = mbedtls_md_hmac_update(&ctx->md_ctx,
ctx->V, md_len)) != 0) {
goto exit;
}
if ((ret = mbedtls_md_hmac_finish(&ctx->md_ctx, ctx->V)) != 0) {
goto exit;
}
}
exit:
mbedtls_platform_zeroize(K, sizeof(K));
return ret;
}
/*
* Simplified HMAC_DRBG initialisation (for use with deterministic ECDSA)
*/
int mbedtls_hmac_drbg_seed_buf(mbedtls_hmac_drbg_context *ctx,
const mbedtls_md_info_t *md_info,
const unsigned char *data, size_t data_len)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if ((ret = mbedtls_md_setup(&ctx->md_ctx, md_info, 1)) != 0) {
return ret;
}
#if defined(MBEDTLS_THREADING_C)
mbedtls_mutex_init(&ctx->mutex);
#endif
/*
* Set initial working state.
* Use the V memory location, which is currently all 0, to initialize the
* MD context with an all-zero key. Then set V to its initial value.
*/
if ((ret = mbedtls_md_hmac_starts(&ctx->md_ctx, ctx->V,
mbedtls_md_get_size(md_info))) != 0) {
return ret;
}
memset(ctx->V, 0x01, mbedtls_md_get_size(md_info));
if ((ret = mbedtls_hmac_drbg_update(ctx, data, data_len)) != 0) {
return ret;
}
return 0;
}
/*
* Internal function used both for seeding and reseeding the DRBG.
* Comments starting with arabic numbers refer to section 10.1.2.4
* of SP800-90A, while roman numbers refer to section 9.2.
*/
static int hmac_drbg_reseed_core(mbedtls_hmac_drbg_context *ctx,
const unsigned char *additional, size_t len,
int use_nonce)
{
unsigned char seed[MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT];
size_t seedlen = 0;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
{
size_t total_entropy_len;
if (use_nonce == 0) {
total_entropy_len = ctx->entropy_len;
} else {
total_entropy_len = ctx->entropy_len * 3 / 2;
}
/* III. Check input length */
if (len > MBEDTLS_HMAC_DRBG_MAX_INPUT ||
total_entropy_len + len > MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT) {
return MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG;
}
}
memset(seed, 0, MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT);
/* IV. Gather entropy_len bytes of entropy for the seed */
if ((ret = ctx->f_entropy(ctx->p_entropy,
seed, ctx->entropy_len)) != 0) {
return MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED;
}
seedlen += ctx->entropy_len;
/* For initial seeding, allow adding of nonce generated
* from the entropy source. See Sect 8.6.7 in SP800-90A. */
if (use_nonce) {
/* Note: We don't merge the two calls to f_entropy() in order
* to avoid requesting too much entropy from f_entropy()
* at once. Specifically, if the underlying digest is not
* SHA-1, 3 / 2 * entropy_len is at least 36 Bytes, which
* is larger than the maximum of 32 Bytes that our own
* entropy source implementation can emit in a single
* call in configurations disabling SHA-512. */
if ((ret = ctx->f_entropy(ctx->p_entropy,
seed + seedlen,
ctx->entropy_len / 2)) != 0) {
return MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED;
}
seedlen += ctx->entropy_len / 2;
}
/* 1. Concatenate entropy and additional data if any */
if (additional != NULL && len != 0) {
memcpy(seed + seedlen, additional, len);
seedlen += len;
}
/* 2. Update state */
if ((ret = mbedtls_hmac_drbg_update(ctx, seed, seedlen)) != 0) {
goto exit;
}
/* 3. Reset reseed_counter */
ctx->reseed_counter = 1;
exit:
/* 4. Done */
mbedtls_platform_zeroize(seed, seedlen);
return ret;
}
/*
* HMAC_DRBG reseeding: 10.1.2.4 + 9.2
*/
int mbedtls_hmac_drbg_reseed(mbedtls_hmac_drbg_context *ctx,
const unsigned char *additional, size_t len)
{
return hmac_drbg_reseed_core(ctx, additional, len, 0);
}
/*
* HMAC_DRBG initialisation (10.1.2.3 + 9.1)
*
* The nonce is not passed as a separate parameter but extracted
* from the entropy source as suggested in 8.6.7.
*/
int mbedtls_hmac_drbg_seed(mbedtls_hmac_drbg_context *ctx,
const mbedtls_md_info_t *md_info,
int (*f_entropy)(void *, unsigned char *, size_t),
void *p_entropy,
const unsigned char *custom,
size_t len)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t md_size;
if ((ret = mbedtls_md_setup(&ctx->md_ctx, md_info, 1)) != 0) {
return ret;
}
/* The mutex is initialized iff the md context is set up. */
#if defined(MBEDTLS_THREADING_C)
mbedtls_mutex_init(&ctx->mutex);
#endif
md_size = mbedtls_md_get_size(md_info);
/*
* Set initial working state.
* Use the V memory location, which is currently all 0, to initialize the
* MD context with an all-zero key. Then set V to its initial value.
*/
if ((ret = mbedtls_md_hmac_starts(&ctx->md_ctx, ctx->V, md_size)) != 0) {
return ret;
}
memset(ctx->V, 0x01, md_size);
ctx->f_entropy = f_entropy;
ctx->p_entropy = p_entropy;
if (ctx->entropy_len == 0) {
/*
* See SP800-57 5.6.1 (p. 65-66) for the security strength provided by
* each hash function, then according to SP800-90A rev1 10.1 table 2,
* min_entropy_len (in bits) is security_strength.
*
* (This also matches the sizes used in the NIST test vectors.)
*/
ctx->entropy_len = md_size <= 20 ? 16 : /* 160-bits hash -> 128 bits */
md_size <= 28 ? 24 : /* 224-bits hash -> 192 bits */
32; /* better (256+) -> 256 bits */
}
if ((ret = hmac_drbg_reseed_core(ctx, custom, len,
1 /* add nonce */)) != 0) {
return ret;
}
return 0;
}
/*
* Set prediction resistance
*/
void mbedtls_hmac_drbg_set_prediction_resistance(mbedtls_hmac_drbg_context *ctx,
int resistance)
{
ctx->prediction_resistance = resistance;
}
/*
* Set entropy length grabbed for seeding
*/
void mbedtls_hmac_drbg_set_entropy_len(mbedtls_hmac_drbg_context *ctx, size_t len)
{
ctx->entropy_len = len;
}
/*
* Set reseed interval
*/
void mbedtls_hmac_drbg_set_reseed_interval(mbedtls_hmac_drbg_context *ctx, int interval)
{
ctx->reseed_interval = interval;
}
/*
* HMAC_DRBG random function with optional additional data:
* 10.1.2.5 (arabic) + 9.3 (Roman)
*/
int mbedtls_hmac_drbg_random_with_add(void *p_rng,
unsigned char *output, size_t out_len,
const unsigned char *additional, size_t add_len)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_hmac_drbg_context *ctx = (mbedtls_hmac_drbg_context *) p_rng;
size_t md_len = mbedtls_md_get_size(ctx->md_ctx.md_info);
size_t left = out_len;
unsigned char *out = output;
/* II. Check request length */
if (out_len > MBEDTLS_HMAC_DRBG_MAX_REQUEST) {
return MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG;
}
/* III. Check input length */
if (add_len > MBEDTLS_HMAC_DRBG_MAX_INPUT) {
return MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG;
}
/* 1. (aka VII and IX) Check reseed counter and PR */
if (ctx->f_entropy != NULL && /* For no-reseeding instances */
(ctx->prediction_resistance == MBEDTLS_HMAC_DRBG_PR_ON ||
ctx->reseed_counter > ctx->reseed_interval)) {
if ((ret = mbedtls_hmac_drbg_reseed(ctx, additional, add_len)) != 0) {
return ret;
}
add_len = 0; /* VII.4 */
}
/* 2. Use additional data if any */
if (additional != NULL && add_len != 0) {
if ((ret = mbedtls_hmac_drbg_update(ctx,
additional, add_len)) != 0) {
goto exit;
}
}
/* 3, 4, 5. Generate bytes */
while (left != 0) {
size_t use_len = left > md_len ? md_len : left;
if ((ret = mbedtls_md_hmac_reset(&ctx->md_ctx)) != 0) {
goto exit;
}
if ((ret = mbedtls_md_hmac_update(&ctx->md_ctx,
ctx->V, md_len)) != 0) {
goto exit;
}
if ((ret = mbedtls_md_hmac_finish(&ctx->md_ctx, ctx->V)) != 0) {
goto exit;
}
memcpy(out, ctx->V, use_len);
out += use_len;
left -= use_len;
}
/* 6. Update */
if ((ret = mbedtls_hmac_drbg_update(ctx,
additional, add_len)) != 0) {
goto exit;
}
/* 7. Update reseed counter */
ctx->reseed_counter++;
exit:
/* 8. Done */
return ret;
}
/*
* HMAC_DRBG random function
*/
int mbedtls_hmac_drbg_random(void *p_rng, unsigned char *output, size_t out_len)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_hmac_drbg_context *ctx = (mbedtls_hmac_drbg_context *) p_rng;
#if defined(MBEDTLS_THREADING_C)
if ((ret = mbedtls_mutex_lock(&ctx->mutex)) != 0) {
return ret;
}
#endif
ret = mbedtls_hmac_drbg_random_with_add(ctx, output, out_len, NULL, 0);
#if defined(MBEDTLS_THREADING_C)
if (mbedtls_mutex_unlock(&ctx->mutex) != 0) {
return MBEDTLS_ERR_THREADING_MUTEX_ERROR;
}
#endif
return ret;
}
/*
* This function resets HMAC_DRBG context to the state immediately
* after initial call of mbedtls_hmac_drbg_init().
*/
void mbedtls_hmac_drbg_free(mbedtls_hmac_drbg_context *ctx)
{
if (ctx == NULL) {
return;
}
#if defined(MBEDTLS_THREADING_C)
/* The mutex is initialized iff the md context is set up. */
if (ctx->md_ctx.md_info != NULL) {
mbedtls_mutex_free(&ctx->mutex);
}
#endif
mbedtls_md_free(&ctx->md_ctx);
mbedtls_platform_zeroize(ctx, sizeof(mbedtls_hmac_drbg_context));
ctx->reseed_interval = MBEDTLS_HMAC_DRBG_RESEED_INTERVAL;
}
#if defined(MBEDTLS_FS_IO)
int mbedtls_hmac_drbg_write_seed_file(mbedtls_hmac_drbg_context *ctx, const char *path)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
FILE *f;
unsigned char buf[MBEDTLS_HMAC_DRBG_MAX_INPUT];
if ((f = fopen(path, "wb")) == NULL) {
return MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR;
}
/* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
mbedtls_setbuf(f, NULL);
if ((ret = mbedtls_hmac_drbg_random(ctx, buf, sizeof(buf))) != 0) {
goto exit;
}
if (fwrite(buf, 1, sizeof(buf), f) != sizeof(buf)) {
ret = MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR;
goto exit;
}
ret = 0;
exit:
fclose(f);
mbedtls_platform_zeroize(buf, sizeof(buf));
return ret;
}
int mbedtls_hmac_drbg_update_seed_file(mbedtls_hmac_drbg_context *ctx, const char *path)
{
int ret = 0;
FILE *f = NULL;
size_t n;
unsigned char buf[MBEDTLS_HMAC_DRBG_MAX_INPUT];
unsigned char c;
if ((f = fopen(path, "rb")) == NULL) {
return MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR;
}
/* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
mbedtls_setbuf(f, NULL);
n = fread(buf, 1, sizeof(buf), f);
if (fread(&c, 1, 1, f) != 0) {
ret = MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG;
goto exit;
}
if (n == 0 || ferror(f)) {
ret = MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR;
goto exit;
}
fclose(f);
f = NULL;
ret = mbedtls_hmac_drbg_update(ctx, buf, n);
exit:
mbedtls_platform_zeroize(buf, sizeof(buf));
if (f != NULL) {
fclose(f);
}
if (ret != 0) {
return ret;
}
return mbedtls_hmac_drbg_write_seed_file(ctx, path);
}
#endif /* MBEDTLS_FS_IO */
#if defined(MBEDTLS_SELF_TEST)
#if !defined(MBEDTLS_MD_CAN_SHA1)
/* Dummy checkup routine */
int mbedtls_hmac_drbg_self_test(int verbose)
{
(void) verbose;
return 0;
}
#else
#define OUTPUT_LEN 80
/* From a NIST PR=true test vector */
static const unsigned char entropy_pr[] = {
0xa0, 0xc9, 0xab, 0x58, 0xf1, 0xe2, 0xe5, 0xa4, 0xde, 0x3e, 0xbd, 0x4f,
0xf7, 0x3e, 0x9c, 0x5b, 0x64, 0xef, 0xd8, 0xca, 0x02, 0x8c, 0xf8, 0x11,
0x48, 0xa5, 0x84, 0xfe, 0x69, 0xab, 0x5a, 0xee, 0x42, 0xaa, 0x4d, 0x42,
0x17, 0x60, 0x99, 0xd4, 0x5e, 0x13, 0x97, 0xdc, 0x40, 0x4d, 0x86, 0xa3,
0x7b, 0xf5, 0x59, 0x54, 0x75, 0x69, 0x51, 0xe4
};
static const unsigned char result_pr[OUTPUT_LEN] = {
0x9a, 0x00, 0xa2, 0xd0, 0x0e, 0xd5, 0x9b, 0xfe, 0x31, 0xec, 0xb1, 0x39,
0x9b, 0x60, 0x81, 0x48, 0xd1, 0x96, 0x9d, 0x25, 0x0d, 0x3c, 0x1e, 0x94,
0x10, 0x10, 0x98, 0x12, 0x93, 0x25, 0xca, 0xb8, 0xfc, 0xcc, 0x2d, 0x54,
0x73, 0x19, 0x70, 0xc0, 0x10, 0x7a, 0xa4, 0x89, 0x25, 0x19, 0x95, 0x5e,
0x4b, 0xc6, 0x00, 0x1d, 0x7f, 0x4e, 0x6a, 0x2b, 0xf8, 0xa3, 0x01, 0xab,
0x46, 0x05, 0x5c, 0x09, 0xa6, 0x71, 0x88, 0xf1, 0xa7, 0x40, 0xee, 0xf3,
0xe1, 0x5c, 0x02, 0x9b, 0x44, 0xaf, 0x03, 0x44
};
/* From a NIST PR=false test vector */
static const unsigned char entropy_nopr[] = {
0x79, 0x34, 0x9b, 0xbf, 0x7c, 0xdd, 0xa5, 0x79, 0x95, 0x57, 0x86, 0x66,
0x21, 0xc9, 0x13, 0x83, 0x11, 0x46, 0x73, 0x3a, 0xbf, 0x8c, 0x35, 0xc8,
0xc7, 0x21, 0x5b, 0x5b, 0x96, 0xc4, 0x8e, 0x9b, 0x33, 0x8c, 0x74, 0xe3,
0xe9, 0x9d, 0xfe, 0xdf
};
static const unsigned char result_nopr[OUTPUT_LEN] = {
0xc6, 0xa1, 0x6a, 0xb8, 0xd4, 0x20, 0x70, 0x6f, 0x0f, 0x34, 0xab, 0x7f,
0xec, 0x5a, 0xdc, 0xa9, 0xd8, 0xca, 0x3a, 0x13, 0x3e, 0x15, 0x9c, 0xa6,
0xac, 0x43, 0xc6, 0xf8, 0xa2, 0xbe, 0x22, 0x83, 0x4a, 0x4c, 0x0a, 0x0a,
0xff, 0xb1, 0x0d, 0x71, 0x94, 0xf1, 0xc1, 0xa5, 0xcf, 0x73, 0x22, 0xec,
0x1a, 0xe0, 0x96, 0x4e, 0xd4, 0xbf, 0x12, 0x27, 0x46, 0xe0, 0x87, 0xfd,
0xb5, 0xb3, 0xe9, 0x1b, 0x34, 0x93, 0xd5, 0xbb, 0x98, 0xfa, 0xed, 0x49,
0xe8, 0x5f, 0x13, 0x0f, 0xc8, 0xa4, 0x59, 0xb7
};
/* "Entropy" from buffer */
static size_t test_offset;
static int hmac_drbg_self_test_entropy(void *data,
unsigned char *buf, size_t len)
{
const unsigned char *p = data;
memcpy(buf, p + test_offset, len);
test_offset += len;
return 0;
}
#define CHK(c) if ((c) != 0) \
{ \
if (verbose != 0) \
mbedtls_printf("failed\n"); \
return 1; \
}
/*
* Checkup routine for HMAC_DRBG with SHA-1
*/
int mbedtls_hmac_drbg_self_test(int verbose)
{
mbedtls_hmac_drbg_context ctx;
unsigned char buf[OUTPUT_LEN];
const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type(MBEDTLS_MD_SHA1);
mbedtls_hmac_drbg_init(&ctx);
/*
* PR = True
*/
if (verbose != 0) {
mbedtls_printf(" HMAC_DRBG (PR = True) : ");
}
test_offset = 0;
CHK(mbedtls_hmac_drbg_seed(&ctx, md_info,
hmac_drbg_self_test_entropy, (void *) entropy_pr,
NULL, 0));
mbedtls_hmac_drbg_set_prediction_resistance(&ctx, MBEDTLS_HMAC_DRBG_PR_ON);
CHK(mbedtls_hmac_drbg_random(&ctx, buf, OUTPUT_LEN));
CHK(mbedtls_hmac_drbg_random(&ctx, buf, OUTPUT_LEN));
CHK(memcmp(buf, result_pr, OUTPUT_LEN));
mbedtls_hmac_drbg_free(&ctx);
mbedtls_hmac_drbg_free(&ctx);
if (verbose != 0) {
mbedtls_printf("passed\n");
}
/*
* PR = False
*/
if (verbose != 0) {
mbedtls_printf(" HMAC_DRBG (PR = False) : ");
}
mbedtls_hmac_drbg_init(&ctx);
test_offset = 0;
CHK(mbedtls_hmac_drbg_seed(&ctx, md_info,
hmac_drbg_self_test_entropy, (void *) entropy_nopr,
NULL, 0));
CHK(mbedtls_hmac_drbg_reseed(&ctx, NULL, 0));
CHK(mbedtls_hmac_drbg_random(&ctx, buf, OUTPUT_LEN));
CHK(mbedtls_hmac_drbg_random(&ctx, buf, OUTPUT_LEN));
CHK(memcmp(buf, result_nopr, OUTPUT_LEN));
mbedtls_hmac_drbg_free(&ctx);
mbedtls_hmac_drbg_free(&ctx);
if (verbose != 0) {
mbedtls_printf("passed\n");
}
if (verbose != 0) {
mbedtls_printf("\n");
}
return 0;
}
#endif /* MBEDTLS_MD_CAN_SHA1 */
#endif /* MBEDTLS_SELF_TEST */
#endif /* MBEDTLS_HMAC_DRBG_C */
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