A local copy of OpenSSL from GitHub
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/*
* Copyright 2020-2021 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 <string.h>
#include <openssl/rand.h>
#include <openssl/core_dispatch.h>
#include <openssl/e_os2.h>
#include <openssl/params.h>
#include <openssl/core_names.h>
#include <openssl/evp.h>
#include <openssl/err.h>
#include <openssl/randerr.h>
#include <openssl/proverr.h>
#include "prov/implementations.h"
#include "prov/provider_ctx.h"
#include "crypto/rand.h"
#include "crypto/rand_pool.h"
static OSSL_FUNC_rand_newctx_fn seed_src_new;
static OSSL_FUNC_rand_freectx_fn seed_src_free;
static OSSL_FUNC_rand_instantiate_fn seed_src_instantiate;
static OSSL_FUNC_rand_uninstantiate_fn seed_src_uninstantiate;
static OSSL_FUNC_rand_generate_fn seed_src_generate;
static OSSL_FUNC_rand_reseed_fn seed_src_reseed;
static OSSL_FUNC_rand_gettable_ctx_params_fn seed_src_gettable_ctx_params;
static OSSL_FUNC_rand_get_ctx_params_fn seed_src_get_ctx_params;
static OSSL_FUNC_rand_verify_zeroization_fn seed_src_verify_zeroization;
static OSSL_FUNC_rand_enable_locking_fn seed_src_enable_locking;
static OSSL_FUNC_rand_lock_fn seed_src_lock;
static OSSL_FUNC_rand_unlock_fn seed_src_unlock;
static OSSL_FUNC_rand_get_seed_fn seed_get_seed;
static OSSL_FUNC_rand_clear_seed_fn seed_clear_seed;
typedef struct {
void *provctx;
int state;
} PROV_SEED_SRC;
static void *seed_src_new(void *provctx, void *parent,
const OSSL_DISPATCH *parent_dispatch)
{
PROV_SEED_SRC *s;
if (parent != NULL) {
ERR_raise(ERR_LIB_PROV, PROV_R_SEED_SOURCES_MUST_NOT_HAVE_A_PARENT);
return NULL;
}
s = OPENSSL_zalloc(sizeof(*s));
if (s == NULL) {
ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
return NULL;
}
s->provctx = provctx;
s->state = EVP_RAND_STATE_UNINITIALISED;
return s;
}
static void seed_src_free(void *vseed)
{
OPENSSL_free(vseed);
}
static int seed_src_instantiate(void *vseed, unsigned int strength,
int prediction_resistance,
const unsigned char *pstr, size_t pstr_len,
ossl_unused const OSSL_PARAM params[])
{
PROV_SEED_SRC *s = (PROV_SEED_SRC *)vseed;
s->state = EVP_RAND_STATE_READY;
return 1;
}
static int seed_src_uninstantiate(void *vseed)
{
PROV_SEED_SRC *s = (PROV_SEED_SRC *)vseed;
s->state = EVP_RAND_STATE_UNINITIALISED;
return 1;
}
static int seed_src_generate(void *vseed, unsigned char *out, size_t outlen,
unsigned int strength,
ossl_unused int prediction_resistance,
ossl_unused const unsigned char *adin,
ossl_unused size_t adin_len)
{
PROV_SEED_SRC *s = (PROV_SEED_SRC *)vseed;
size_t entropy_available;
RAND_POOL *pool;
if (s->state != EVP_RAND_STATE_READY) {
ERR_raise(ERR_LIB_PROV,
s->state == EVP_RAND_STATE_ERROR ? PROV_R_IN_ERROR_STATE
: PROV_R_NOT_INSTANTIATED);
return 0;
}
pool = ossl_rand_pool_new(strength, 1, outlen, outlen);
if (pool == NULL) {
ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
return 0;
}
/* Get entropy by polling system entropy sources. */
entropy_available = ossl_pool_acquire_entropy(pool);
if (entropy_available > 0)
memcpy(out, ossl_rand_pool_buffer(pool), ossl_rand_pool_length(pool));
ossl_rand_pool_free(pool);
return entropy_available > 0;
}
static int seed_src_reseed(void *vseed,
ossl_unused int prediction_resistance,
ossl_unused const unsigned char *ent,
ossl_unused size_t ent_len,
ossl_unused const unsigned char *adin,
ossl_unused size_t adin_len)
{
PROV_SEED_SRC *s = (PROV_SEED_SRC *)vseed;
if (s->state != EVP_RAND_STATE_READY) {
ERR_raise(ERR_LIB_PROV,
s->state == EVP_RAND_STATE_ERROR ? PROV_R_IN_ERROR_STATE
: PROV_R_NOT_INSTANTIATED);
return 0;
}
return 1;
}
static int seed_src_get_ctx_params(void *vseed, OSSL_PARAM params[])
{
PROV_SEED_SRC *s = (PROV_SEED_SRC *)vseed;
OSSL_PARAM *p;
p = OSSL_PARAM_locate(params, OSSL_RAND_PARAM_STATE);
if (p != NULL && !OSSL_PARAM_set_int(p, s->state))
return 0;
p = OSSL_PARAM_locate(params, OSSL_RAND_PARAM_STRENGTH);
if (p != NULL && !OSSL_PARAM_set_int(p, 1024))
return 0;
p = OSSL_PARAM_locate(params, OSSL_RAND_PARAM_MAX_REQUEST);
if (p != NULL && !OSSL_PARAM_set_size_t(p, 128))
return 0;
return 1;
}
static const OSSL_PARAM *seed_src_gettable_ctx_params(ossl_unused void *vseed,
ossl_unused void *provctx)
{
static const OSSL_PARAM known_gettable_ctx_params[] = {
OSSL_PARAM_int(OSSL_RAND_PARAM_STATE, NULL),
OSSL_PARAM_uint(OSSL_RAND_PARAM_STRENGTH, NULL),
OSSL_PARAM_size_t(OSSL_RAND_PARAM_MAX_REQUEST, NULL),
OSSL_PARAM_END
};
return known_gettable_ctx_params;
}
static int seed_src_verify_zeroization(ossl_unused void *vseed)
{
return 1;
}
static size_t seed_get_seed(void *vseed, unsigned char **pout,
int entropy, size_t min_len, size_t max_len,
int prediction_resistance,
const unsigned char *adin, size_t adin_len)
{
size_t bytes_needed;
unsigned char *p;
/*
* Figure out how many bytes we need.
* This assumes that the seed sources provide eight bits of entropy
* per byte. For lower quality sources, the formula will need to be
* different.
*/
bytes_needed = entropy >= 0 ? (entropy + 7) / 8 : 0;
if (bytes_needed < min_len)
bytes_needed = min_len;
if (bytes_needed > max_len) {
ERR_raise(ERR_LIB_PROV, PROV_R_ENTROPY_SOURCE_STRENGTH_TOO_WEAK);
return 0;
}
p = OPENSSL_secure_malloc(bytes_needed);
if (p == NULL) {
ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
return 0;
}
*pout = p;
if (seed_src_generate(vseed, p, bytes_needed, 0, prediction_resistance,
adin, adin_len) != 0)
return bytes_needed;
OPENSSL_secure_clear_free(p, bytes_needed);
return 0;
}
static void seed_clear_seed(ossl_unused void *vdrbg,
unsigned char *out, size_t outlen)
{
OPENSSL_secure_clear_free(out, outlen);
}
static int seed_src_enable_locking(ossl_unused void *vseed)
{
return 1;
}
int seed_src_lock(ossl_unused void *vctx)
{
return 1;
}
void seed_src_unlock(ossl_unused void *vctx)
{
}
const OSSL_DISPATCH ossl_seed_src_functions[] = {
{ OSSL_FUNC_RAND_NEWCTX, (void(*)(void))seed_src_new },
{ OSSL_FUNC_RAND_FREECTX, (void(*)(void))seed_src_free },
{ OSSL_FUNC_RAND_INSTANTIATE,
(void(*)(void))seed_src_instantiate },
{ OSSL_FUNC_RAND_UNINSTANTIATE,
(void(*)(void))seed_src_uninstantiate },
{ OSSL_FUNC_RAND_GENERATE, (void(*)(void))seed_src_generate },
{ OSSL_FUNC_RAND_RESEED, (void(*)(void))seed_src_reseed },
{ OSSL_FUNC_RAND_ENABLE_LOCKING, (void(*)(void))seed_src_enable_locking },
{ OSSL_FUNC_RAND_LOCK, (void(*)(void))seed_src_lock },
{ OSSL_FUNC_RAND_UNLOCK, (void(*)(void))seed_src_unlock },
{ OSSL_FUNC_RAND_GETTABLE_CTX_PARAMS,
(void(*)(void))seed_src_gettable_ctx_params },
{ OSSL_FUNC_RAND_GET_CTX_PARAMS, (void(*)(void))seed_src_get_ctx_params },
{ OSSL_FUNC_RAND_VERIFY_ZEROIZATION,
(void(*)(void))seed_src_verify_zeroization },
{ OSSL_FUNC_RAND_GET_SEED, (void(*)(void))seed_get_seed },
{ OSSL_FUNC_RAND_CLEAR_SEED, (void(*)(void))seed_clear_seed },
{ 0, NULL }
};