A local copy of OpenSSL from GitHub
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/*
* Copyright 2011-2021 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/sha.h>
#include <openssl/crypto.h>
#include <openssl/err.h>
#include <openssl/rand.h>
#include <openssl/core_dispatch.h>
#include <openssl/proverr.h>
#include "internal/thread_once.h"
#include "prov/providercommon.h"
#include "prov/provider_ctx.h"
#include "prov/provider_util.h"
#include "prov/implementations.h"
#include "drbg_local.h"
static OSSL_FUNC_rand_newctx_fn drbg_hash_new_wrapper;
static OSSL_FUNC_rand_freectx_fn drbg_hash_free;
static OSSL_FUNC_rand_instantiate_fn drbg_hash_instantiate_wrapper;
static OSSL_FUNC_rand_uninstantiate_fn drbg_hash_uninstantiate_wrapper;
static OSSL_FUNC_rand_generate_fn drbg_hash_generate_wrapper;
static OSSL_FUNC_rand_reseed_fn drbg_hash_reseed_wrapper;
static OSSL_FUNC_rand_settable_ctx_params_fn drbg_hash_settable_ctx_params;
static OSSL_FUNC_rand_set_ctx_params_fn drbg_hash_set_ctx_params;
static OSSL_FUNC_rand_gettable_ctx_params_fn drbg_hash_gettable_ctx_params;
static OSSL_FUNC_rand_get_ctx_params_fn drbg_hash_get_ctx_params;
static OSSL_FUNC_rand_verify_zeroization_fn drbg_hash_verify_zeroization;
/* 888 bits from SP800-90Ar1 10.1 table 2 */
#define HASH_PRNG_MAX_SEEDLEN (888/8)
/* 440 bits from SP800-90Ar1 10.1 table 2 */
#define HASH_PRNG_SMALL_SEEDLEN (440/8)
/* Determine what seedlen to use based on the block length */
#define MAX_BLOCKLEN_USING_SMALL_SEEDLEN (256/8)
#define INBYTE_IGNORE ((unsigned char)0xFF)
typedef struct rand_drbg_hash_st {
PROV_DIGEST digest;
EVP_MD_CTX *ctx;
size_t blocklen;
unsigned char V[HASH_PRNG_MAX_SEEDLEN];
unsigned char C[HASH_PRNG_MAX_SEEDLEN];
/* Temporary value storage: should always exceed max digest length */
unsigned char vtmp[HASH_PRNG_MAX_SEEDLEN];
} PROV_DRBG_HASH;
/*
* SP800-90Ar1 10.3.1 Derivation function using a Hash Function (Hash_df).
* The input string used is composed of:
* inbyte - An optional leading byte (ignore if equal to INBYTE_IGNORE)
* in - input string 1 (A Non NULL value).
* in2 - optional input string (Can be NULL).
* in3 - optional input string (Can be NULL).
* These are concatenated as part of the DigestUpdate process.
*/
static int hash_df(PROV_DRBG *drbg, unsigned char *out,
const unsigned char inbyte,
const unsigned char *in, size_t inlen,
const unsigned char *in2, size_t in2len,
const unsigned char *in3, size_t in3len)
{
PROV_DRBG_HASH *hash = (PROV_DRBG_HASH *)drbg->data;
EVP_MD_CTX *ctx = hash->ctx;
unsigned char *vtmp = hash->vtmp;
/* tmp = counter || num_bits_returned || [inbyte] */
unsigned char tmp[1 + 4 + 1];
int tmp_sz = 0;
size_t outlen = drbg->seedlen;
size_t num_bits_returned = outlen * 8;
/*
* No need to check outlen size here, as the standard only ever needs
* seedlen bytes which is always less than the maximum permitted.
*/
/* (Step 3) counter = 1 (tmp[0] is the 8 bit counter) */
tmp[tmp_sz++] = 1;
/* tmp[1..4] is the fixed 32 bit no_of_bits_to_return */
tmp[tmp_sz++] = (unsigned char)((num_bits_returned >> 24) & 0xff);
tmp[tmp_sz++] = (unsigned char)((num_bits_returned >> 16) & 0xff);
tmp[tmp_sz++] = (unsigned char)((num_bits_returned >> 8) & 0xff);
tmp[tmp_sz++] = (unsigned char)(num_bits_returned & 0xff);
/* Tack the additional input byte onto the end of tmp if it exists */
if (inbyte != INBYTE_IGNORE)
tmp[tmp_sz++] = inbyte;
/* (Step 4) */
for (;;) {
/*
* (Step 4.1) out = out || Hash(tmp || in || [in2] || [in3])
* (where tmp = counter || num_bits_returned || [inbyte])
*/
if (!(EVP_DigestInit_ex(ctx, ossl_prov_digest_md(&hash->digest), NULL)
&& EVP_DigestUpdate(ctx, tmp, tmp_sz)
&& EVP_DigestUpdate(ctx, in, inlen)
&& (in2 == NULL || EVP_DigestUpdate(ctx, in2, in2len))
&& (in3 == NULL || EVP_DigestUpdate(ctx, in3, in3len))))
return 0;
if (outlen < hash->blocklen) {
if (!EVP_DigestFinal(ctx, vtmp, NULL))
return 0;
memcpy(out, vtmp, outlen);
OPENSSL_cleanse(vtmp, hash->blocklen);
break;
} else if(!EVP_DigestFinal(ctx, out, NULL)) {
return 0;
}
outlen -= hash->blocklen;
if (outlen == 0)
break;
/* (Step 4.2) counter++ */
tmp[0]++;
out += hash->blocklen;
}
return 1;
}
/* Helper function that just passes 2 input parameters to hash_df() */
static int hash_df1(PROV_DRBG *drbg, unsigned char *out,
const unsigned char in_byte,
const unsigned char *in1, size_t in1len)
{
return hash_df(drbg, out, in_byte, in1, in1len, NULL, 0, NULL, 0);
}
/*
* Add 2 byte buffers together. The first elements in each buffer are the top
* most bytes. The result is stored in the dst buffer.
* The final carry is ignored i.e: dst = (dst + in) mod (2^seedlen_bits).
* where dst size is drbg->seedlen, and inlen <= drbg->seedlen.
*/
static int add_bytes(PROV_DRBG *drbg, unsigned char *dst,
unsigned char *in, size_t inlen)
{
size_t i;
int result;
const unsigned char *add;
unsigned char carry = 0, *d;
assert(drbg->seedlen >= 1 && inlen >= 1 && inlen <= drbg->seedlen);
d = &dst[drbg->seedlen - 1];
add = &in[inlen - 1];
for (i = inlen; i > 0; i--, d--, add--) {
result = *d + *add + carry;
carry = (unsigned char)(result >> 8);
*d = (unsigned char)(result & 0xff);
}
if (carry != 0) {
/* Add the carry to the top of the dst if inlen is not the same size */
for (i = drbg->seedlen - inlen; i > 0; --i, d--) {
*d += 1; /* Carry can only be 1 */
if (*d != 0) /* exit if carry doesnt propagate to the next byte */
break;
}
}
return 1;
}
/* V = (V + Hash(inbyte || V || [additional_input]) mod (2^seedlen) */
static int add_hash_to_v(PROV_DRBG *drbg, unsigned char inbyte,
const unsigned char *adin, size_t adinlen)
{
PROV_DRBG_HASH *hash = (PROV_DRBG_HASH *)drbg->data;
EVP_MD_CTX *ctx = hash->ctx;
return EVP_DigestInit_ex(ctx, ossl_prov_digest_md(&hash->digest), NULL)
&& EVP_DigestUpdate(ctx, &inbyte, 1)
&& EVP_DigestUpdate(ctx, hash->V, drbg->seedlen)
&& (adin == NULL || EVP_DigestUpdate(ctx, adin, adinlen))
&& EVP_DigestFinal(ctx, hash->vtmp, NULL)
&& add_bytes(drbg, hash->V, hash->vtmp, hash->blocklen);
}
/*
* The Hashgen() as listed in SP800-90Ar1 10.1.1.4 Hash_DRBG_Generate_Process.
*
* drbg contains the current value of V.
* outlen is the requested number of bytes.
* out is a buffer to return the generated bits.
*
* The algorithm to generate the bits is:
* data = V
* w = NULL
* for (i = 1 to m) {
* W = W || Hash(data)
* data = (data + 1) mod (2^seedlen)
* }
* out = Leftmost(W, outlen)
*
* Returns zero if an error occurs otherwise it returns 1.
*/
static int hash_gen(PROV_DRBG *drbg, unsigned char *out, size_t outlen)
{
PROV_DRBG_HASH *hash = (PROV_DRBG_HASH *)drbg->data;
unsigned char one = 1;
if (outlen == 0)
return 1;
memcpy(hash->vtmp, hash->V, drbg->seedlen);
for(;;) {
if (!EVP_DigestInit_ex(hash->ctx, ossl_prov_digest_md(&hash->digest),
NULL)
|| !EVP_DigestUpdate(hash->ctx, hash->vtmp, drbg->seedlen))
return 0;
if (outlen < hash->blocklen) {
if (!EVP_DigestFinal(hash->ctx, hash->vtmp, NULL))
return 0;
memcpy(out, hash->vtmp, outlen);
return 1;
} else {
if (!EVP_DigestFinal(hash->ctx, out, NULL))
return 0;
outlen -= hash->blocklen;
if (outlen == 0)
break;
out += hash->blocklen;
}
add_bytes(drbg, hash->vtmp, &one, 1);
}
return 1;
}
/*
* SP800-90Ar1 10.1.1.2 Hash_DRBG_Instantiate_Process:
*
* ent is entropy input obtained from a randomness source of length ent_len.
* nonce is a string of bytes of length nonce_len.
* pstr is a personalization string received from an application. May be NULL.
*
* Returns zero if an error occurs otherwise it returns 1.
*/
static int drbg_hash_instantiate(PROV_DRBG *drbg,
const unsigned char *ent, size_t ent_len,
const unsigned char *nonce, size_t nonce_len,
const unsigned char *pstr, size_t pstr_len)
{
PROV_DRBG_HASH *hash = (PROV_DRBG_HASH *)drbg->data;
EVP_MD_CTX_free(hash->ctx);
hash->ctx = EVP_MD_CTX_new();
/* (Step 1-3) V = Hash_df(entropy||nonce||pers, seedlen) */
return hash->ctx != NULL
&& hash_df(drbg, hash->V, INBYTE_IGNORE,
ent, ent_len, nonce, nonce_len, pstr, pstr_len)
/* (Step 4) C = Hash_df(0x00||V, seedlen) */
&& hash_df1(drbg, hash->C, 0x00, hash->V, drbg->seedlen);
}
static int drbg_hash_instantiate_wrapper(void *vdrbg, unsigned int strength,
int prediction_resistance,
const unsigned char *pstr,
size_t pstr_len,
const OSSL_PARAM params[])
{
PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
if (!ossl_prov_is_running() || !drbg_hash_set_ctx_params(drbg, params))
return 0;
return ossl_prov_drbg_instantiate(drbg, strength, prediction_resistance,
pstr, pstr_len);
}
/*
* SP800-90Ar1 10.1.1.3 Hash_DRBG_Reseed_Process:
*
* ent is entropy input bytes obtained from a randomness source.
* addin is additional input received from an application. May be NULL.
*
* Returns zero if an error occurs otherwise it returns 1.
*/
static int drbg_hash_reseed(PROV_DRBG *drbg,
const unsigned char *ent, size_t ent_len,
const unsigned char *adin, size_t adin_len)
{
PROV_DRBG_HASH *hash = (PROV_DRBG_HASH *)drbg->data;
/* (Step 1-2) V = Hash_df(0x01 || V || entropy_input || additional_input) */
/* V about to be updated so use C as output instead */
if (!hash_df(drbg, hash->C, 0x01, hash->V, drbg->seedlen, ent, ent_len,
adin, adin_len))
return 0;
memcpy(hash->V, hash->C, drbg->seedlen);
/* (Step 4) C = Hash_df(0x00||V, seedlen) */
return hash_df1(drbg, hash->C, 0x00, hash->V, drbg->seedlen);
}
static int drbg_hash_reseed_wrapper(void *vdrbg, int prediction_resistance,
const unsigned char *ent, size_t ent_len,
const unsigned char *adin, size_t adin_len)
{
PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
return ossl_prov_drbg_reseed(drbg, prediction_resistance, ent, ent_len,
adin, adin_len);
}
/*
* SP800-90Ar1 10.1.1.4 Hash_DRBG_Generate_Process:
*
* Generates pseudo random bytes using the drbg.
* out is a buffer to fill with outlen bytes of pseudo random data.
* addin is additional input received from an application. May be NULL.
*
* Returns zero if an error occurs otherwise it returns 1.
*/
static int drbg_hash_generate(PROV_DRBG *drbg,
unsigned char *out, size_t outlen,
const unsigned char *adin, size_t adin_len)
{
PROV_DRBG_HASH *hash = (PROV_DRBG_HASH *)drbg->data;
unsigned char counter[4];
int reseed_counter = drbg->generate_counter;
counter[0] = (unsigned char)((reseed_counter >> 24) & 0xff);
counter[1] = (unsigned char)((reseed_counter >> 16) & 0xff);
counter[2] = (unsigned char)((reseed_counter >> 8) & 0xff);
counter[3] = (unsigned char)(reseed_counter & 0xff);
return hash->ctx != NULL
&& (adin == NULL
/* (Step 2) if adin != NULL then V = V + Hash(0x02||V||adin) */
|| adin_len == 0
|| add_hash_to_v(drbg, 0x02, adin, adin_len))
/* (Step 3) Hashgen(outlen, V) */
&& hash_gen(drbg, out, outlen)
/* (Step 4/5) H = V = (V + Hash(0x03||V) mod (2^seedlen_bits) */
&& add_hash_to_v(drbg, 0x03, NULL, 0)
/* (Step 5) V = (V + H + C + reseed_counter) mod (2^seedlen_bits) */
/* V = (V + C) mod (2^seedlen_bits) */
&& add_bytes(drbg, hash->V, hash->C, drbg->seedlen)
/* V = (V + reseed_counter) mod (2^seedlen_bits) */
&& add_bytes(drbg, hash->V, counter, 4);
}
static int drbg_hash_generate_wrapper
(void *vdrbg, unsigned char *out, size_t outlen, unsigned int strength,
int prediction_resistance, const unsigned char *adin, size_t adin_len)
{
PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
return ossl_prov_drbg_generate(drbg, out, outlen, strength,
prediction_resistance, adin, adin_len);
}
static int drbg_hash_uninstantiate(PROV_DRBG *drbg)
{
PROV_DRBG_HASH *hash = (PROV_DRBG_HASH *)drbg->data;
OPENSSL_cleanse(hash->V, sizeof(hash->V));
OPENSSL_cleanse(hash->C, sizeof(hash->C));
OPENSSL_cleanse(hash->vtmp, sizeof(hash->vtmp));
return ossl_prov_drbg_uninstantiate(drbg);
}
static int drbg_hash_uninstantiate_wrapper(void *vdrbg)
{
return drbg_hash_uninstantiate((PROV_DRBG *)vdrbg);
}
static int drbg_hash_verify_zeroization(void *vdrbg)
{
PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
PROV_DRBG_HASH *hash = (PROV_DRBG_HASH *)drbg->data;
PROV_DRBG_VERYIFY_ZEROIZATION(hash->V);
PROV_DRBG_VERYIFY_ZEROIZATION(hash->C);
PROV_DRBG_VERYIFY_ZEROIZATION(hash->vtmp);
return 1;
}
static int drbg_hash_new(PROV_DRBG *ctx)
{
PROV_DRBG_HASH *hash;
hash = OPENSSL_secure_zalloc(sizeof(*hash));
if (hash == NULL) {
ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
return 0;
}
ctx->data = hash;
ctx->seedlen = HASH_PRNG_MAX_SEEDLEN;
ctx->max_entropylen = DRBG_MAX_LENGTH;
ctx->max_noncelen = DRBG_MAX_LENGTH;
ctx->max_perslen = DRBG_MAX_LENGTH;
ctx->max_adinlen = DRBG_MAX_LENGTH;
/* Maximum number of bits per request = 2^19 = 2^16 bytes */
ctx->max_request = 1 << 16;
return 1;
}
static void *drbg_hash_new_wrapper(void *provctx, void *parent,
const OSSL_DISPATCH *parent_dispatch)
{
return ossl_rand_drbg_new(provctx, parent, parent_dispatch, &drbg_hash_new,
&drbg_hash_instantiate, &drbg_hash_uninstantiate,
&drbg_hash_reseed, &drbg_hash_generate);
}
static void drbg_hash_free(void *vdrbg)
{
PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
PROV_DRBG_HASH *hash;
if (drbg != NULL && (hash = (PROV_DRBG_HASH *)drbg->data) != NULL) {
EVP_MD_CTX_free(hash->ctx);
ossl_prov_digest_reset(&hash->digest);
OPENSSL_secure_clear_free(hash, sizeof(*hash));
}
ossl_rand_drbg_free(drbg);
}
static int drbg_hash_get_ctx_params(void *vdrbg, OSSL_PARAM params[])
{
PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
PROV_DRBG_HASH *hash = (PROV_DRBG_HASH *)drbg->data;
const EVP_MD *md;
OSSL_PARAM *p;
p = OSSL_PARAM_locate(params, OSSL_DRBG_PARAM_DIGEST);
if (p != NULL) {
md = ossl_prov_digest_md(&hash->digest);
if (md == NULL || !OSSL_PARAM_set_utf8_string(p, EVP_MD_get0_name(md)))
return 0;
}
return ossl_drbg_get_ctx_params(drbg, params);
}
static const OSSL_PARAM *drbg_hash_gettable_ctx_params(ossl_unused void *vctx,
ossl_unused void *p_ctx)
{
static const OSSL_PARAM known_gettable_ctx_params[] = {
OSSL_PARAM_utf8_string(OSSL_DRBG_PARAM_DIGEST, NULL, 0),
OSSL_PARAM_DRBG_GETTABLE_CTX_COMMON,
OSSL_PARAM_END
};
return known_gettable_ctx_params;
}
static int drbg_hash_set_ctx_params(void *vctx, const OSSL_PARAM params[])
{
PROV_DRBG *ctx = (PROV_DRBG *)vctx;
PROV_DRBG_HASH *hash = (PROV_DRBG_HASH *)ctx->data;
OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
const EVP_MD *md;
if (!ossl_prov_digest_load_from_params(&hash->digest, params, libctx))
return 0;
md = ossl_prov_digest_md(&hash->digest);
if (md != NULL) {
if ((EVP_MD_get_flags(md) & EVP_MD_FLAG_XOF) != 0) {
ERR_raise(ERR_LIB_PROV, PROV_R_XOF_DIGESTS_NOT_ALLOWED);
return 0;
}
/* These are taken from SP 800-90 10.1 Table 2 */
hash->blocklen = EVP_MD_get_size(md);
/* See SP800-57 Part1 Rev4 5.6.1 Table 3 */
ctx->strength = 64 * (hash->blocklen >> 3);
if (ctx->strength > 256)
ctx->strength = 256;
if (hash->blocklen > MAX_BLOCKLEN_USING_SMALL_SEEDLEN)
ctx->seedlen = HASH_PRNG_MAX_SEEDLEN;
else
ctx->seedlen = HASH_PRNG_SMALL_SEEDLEN;
ctx->min_entropylen = ctx->strength / 8;
ctx->min_noncelen = ctx->min_entropylen / 2;
}
return ossl_drbg_set_ctx_params(ctx, params);
}
static const OSSL_PARAM *drbg_hash_settable_ctx_params(ossl_unused void *vctx,
ossl_unused void *p_ctx)
{
static const OSSL_PARAM known_settable_ctx_params[] = {
OSSL_PARAM_utf8_string(OSSL_DRBG_PARAM_PROPERTIES, NULL, 0),
OSSL_PARAM_utf8_string(OSSL_DRBG_PARAM_DIGEST, NULL, 0),
OSSL_PARAM_DRBG_SETTABLE_CTX_COMMON,
OSSL_PARAM_END
};
return known_settable_ctx_params;
}
const OSSL_DISPATCH ossl_drbg_hash_functions[] = {
{ OSSL_FUNC_RAND_NEWCTX, (void(*)(void))drbg_hash_new_wrapper },
{ OSSL_FUNC_RAND_FREECTX, (void(*)(void))drbg_hash_free },
{ OSSL_FUNC_RAND_INSTANTIATE,
(void(*)(void))drbg_hash_instantiate_wrapper },
{ OSSL_FUNC_RAND_UNINSTANTIATE,
(void(*)(void))drbg_hash_uninstantiate_wrapper },
{ OSSL_FUNC_RAND_GENERATE, (void(*)(void))drbg_hash_generate_wrapper },
{ OSSL_FUNC_RAND_RESEED, (void(*)(void))drbg_hash_reseed_wrapper },
{ OSSL_FUNC_RAND_ENABLE_LOCKING, (void(*)(void))ossl_drbg_enable_locking },
{ OSSL_FUNC_RAND_LOCK, (void(*)(void))ossl_drbg_lock },
{ OSSL_FUNC_RAND_UNLOCK, (void(*)(void))ossl_drbg_unlock },
{ OSSL_FUNC_RAND_SETTABLE_CTX_PARAMS,
(void(*)(void))drbg_hash_settable_ctx_params },
{ OSSL_FUNC_RAND_SET_CTX_PARAMS, (void(*)(void))drbg_hash_set_ctx_params },
{ OSSL_FUNC_RAND_GETTABLE_CTX_PARAMS,
(void(*)(void))drbg_hash_gettable_ctx_params },
{ OSSL_FUNC_RAND_GET_CTX_PARAMS, (void(*)(void))drbg_hash_get_ctx_params },
{ OSSL_FUNC_RAND_VERIFY_ZEROIZATION,
(void(*)(void))drbg_hash_verify_zeroization },
{ OSSL_FUNC_RAND_GET_SEED, (void(*)(void))ossl_drbg_get_seed },
{ OSSL_FUNC_RAND_CLEAR_SEED, (void(*)(void))ossl_drbg_clear_seed },
{ 0, NULL }
};