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openssl/crypto/rand/drbg_lib.c
Dr. Matthias St. Pierre a27cb956c0 Fix: uninstantiation breaks the RAND_DRBG callback mechanism 
The RAND_DRBG callbacks are wrappers around the EVP_RAND callbacks.
During uninstantiation, the EVP_RAND callbacks got lost while the
RAND_DRBG callbacks remained, because RAND_DRBG_uninstantiate()
calls RAND_DRBG_set(), which recreates the EVP_RAND object.
This was causing drbgtest failures.

This commit fixes the problem by adding code to RAND_DRBG_set() for
saving and restoring the EVP_RAND callbacks.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/11195)
2020-07-23 01:12:48 +02:00

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/*
* Copyright 2011-2020 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
*/
/*
* RAND_DRBG_set is deprecated for public use, but still ok for
* internal use.
*/
#include "internal/deprecated.h"
#include <string.h>
#include <openssl/crypto.h>
#include <openssl/err.h>
#include <openssl/rand.h>
#include <openssl/core_names.h>
#include "rand_local.h"
#include "internal/thread_once.h"
#include "crypto/rand.h"
#include "crypto/cryptlib.h"
/*
* Support framework for NIST SP 800-90A DRBG
*
* See manual page RAND_DRBG(7) for a general overview.
*
* The OpenSSL model is to have new and free functions, and that new
* does all initialization. That is not the NIST model, which has
* instantiation and un-instantiate, and re-use within a new/free
* lifecycle. (No doubt this comes from the desire to support hardware
* DRBG, where allocation of resources on something like an HSM is
* a much bigger deal than just re-setting an allocated resource.)
*/
typedef struct drbg_global_st {
/*
* The three shared DRBG instances
*
* There are three shared DRBG instances: <primary>, <public>, and
* <private>. The <public> and <private> DRBGs are secondary ones.
* These are used for non-secret (e.g. nonces) and secret
* (e.g. private keys) data respectively.
*/
CRYPTO_RWLOCK *lock;
/*
* The <primary> DRBG
*
* Not used directly by the application, only for reseeding the two other
* DRBGs. It reseeds itself by pulling either randomness from os entropy
* sources or by consuming randomness which was added by RAND_add().
*
* The <primary> DRBG is a global instance which is accessed concurrently by
* all threads. The necessary locking is managed automatically by its child
* DRBG instances during reseeding.
*/
RAND_DRBG *primary_drbg;
/*
* The <public> DRBG
*
* Used by default for generating random bytes using RAND_bytes().
*
* The <public> secondary DRBG is thread-local, i.e., there is one instance
* per thread.
*/
CRYPTO_THREAD_LOCAL public_drbg;
/*
* The <private> DRBG
*
* Used by default for generating private keys using RAND_priv_bytes()
*
* The <private> secondary DRBG is thread-local, i.e., there is one
* instance per thread.
*/
CRYPTO_THREAD_LOCAL private_drbg;
} DRBG_GLOBAL;
#define RAND_DRBG_TYPE_FLAGS ( \
RAND_DRBG_FLAG_PRIMARY | RAND_DRBG_FLAG_PUBLIC | RAND_DRBG_FLAG_PRIVATE )
#define RAND_DRBG_TYPE_PRIMARY 0
#define RAND_DRBG_TYPE_PUBLIC 1
#define RAND_DRBG_TYPE_PRIVATE 2
/* Defaults */
static int rand_drbg_type[3] = {
RAND_DRBG_TYPE, /* Primary */
RAND_DRBG_TYPE, /* Public */
RAND_DRBG_TYPE /* Private */
};
static unsigned int rand_drbg_flags[3] = {
RAND_DRBG_FLAGS | RAND_DRBG_FLAG_PRIMARY, /* Primary */
RAND_DRBG_FLAGS | RAND_DRBG_FLAG_PUBLIC, /* Public */
RAND_DRBG_FLAGS | RAND_DRBG_FLAG_PRIVATE /* Private */
};
static unsigned int primary_reseed_interval = PRIMARY_RESEED_INTERVAL;
static unsigned int secondary_reseed_interval = SECONDARY_RESEED_INTERVAL;
static time_t primary_reseed_time_interval = PRIMARY_RESEED_TIME_INTERVAL;
static time_t secondary_reseed_time_interval = SECONDARY_RESEED_TIME_INTERVAL;
/* A logical OR of all used DRBG flag bits (currently there is only one) */
static const unsigned int rand_drbg_used_flags =
RAND_DRBG_FLAG_CTR_NO_DF | RAND_DRBG_FLAG_HMAC | RAND_DRBG_TYPE_FLAGS;
static RAND_DRBG *drbg_setup(OPENSSL_CTX *ctx, RAND_DRBG *parent,
int drbg_type);
static int get_drbg_params(int type, unsigned int flags, const char **name,
OSSL_PARAM params[3])
{
OSSL_PARAM *p = params;
switch (type) {
case 0:
return 1;
default:
return 0;
#define CTR(v) \
*name = "CTR-DRBG"; \
*p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_CIPHER, v, 0)
case NID_aes_128_ctr:
CTR(SN_aes_128_ctr);
break;
case NID_aes_192_ctr:
CTR(SN_aes_192_ctr);
break;
case NID_aes_256_ctr:
CTR(SN_aes_256_ctr);
break;
#define DGST(v) \
*p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_DIGEST, v, 0); \
if ((flags & RAND_DRBG_FLAG_HMAC) == 0) { \
*name = "HASH-DRBG"; \
} else { \
*name = "HMAC-DRBG"; \
*p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_MAC, \
SN_hmac, 0); \
}
case NID_sha1:
DGST(SN_sha1);
break;
case NID_sha224:
DGST(SN_sha224);
break;
case NID_sha256:
DGST(SN_sha256);
break;
case NID_sha384:
DGST(SN_sha384);
break;
case NID_sha512:
DGST(SN_sha512);
break;
case NID_sha512_224:
DGST(SN_sha512_224);
break;
case NID_sha512_256:
DGST(SN_sha512_256);
break;
case NID_sha3_224:
DGST(SN_sha3_224);
break;
case NID_sha3_256:
DGST(SN_sha3_256);
break;
case NID_sha3_384:
DGST(SN_sha3_384);
break;
case NID_sha3_512:
DGST(SN_sha3_512);
}
*p = OSSL_PARAM_construct_end();
return 1;
}
/*
* Initialize the OPENSSL_CTX global DRBGs on first use.
* Returns the allocated global data on success or NULL on failure.
*/
static void *drbg_ossl_ctx_new(OPENSSL_CTX *libctx)
{
DRBG_GLOBAL *dgbl = OPENSSL_zalloc(sizeof(*dgbl));
if (dgbl == NULL)
return NULL;
#ifndef FIPS_MODULE
/*
* We need to ensure that base libcrypto thread handling has been
* initialised.
*/
OPENSSL_init_crypto(0, NULL);
#endif
dgbl->lock = CRYPTO_THREAD_lock_new();
if (dgbl->lock == NULL)
goto err0;
if (!CRYPTO_THREAD_init_local(&dgbl->private_drbg, NULL))
goto err1;
if (!CRYPTO_THREAD_init_local(&dgbl->public_drbg, NULL))
goto err2;
return dgbl;
err2:
CRYPTO_THREAD_cleanup_local(&dgbl->private_drbg);
err1:
CRYPTO_THREAD_lock_free(dgbl->lock);
err0:
OPENSSL_free(dgbl);
return NULL;
}
static void drbg_ossl_ctx_free(void *vdgbl)
{
DRBG_GLOBAL *dgbl = vdgbl;
if (dgbl == NULL)
return;
CRYPTO_THREAD_lock_free(dgbl->lock);
RAND_DRBG_free(dgbl->primary_drbg);
CRYPTO_THREAD_cleanup_local(&dgbl->private_drbg);
CRYPTO_THREAD_cleanup_local(&dgbl->public_drbg);
OPENSSL_free(dgbl);
}
static const OPENSSL_CTX_METHOD drbg_ossl_ctx_method = {
drbg_ossl_ctx_new,
drbg_ossl_ctx_free,
};
static DRBG_GLOBAL *drbg_get_global(OPENSSL_CTX *libctx)
{
return openssl_ctx_get_data(libctx, OPENSSL_CTX_DRBG_INDEX,
&drbg_ossl_ctx_method);
}
/*
* Set the |drbg|'s callback data pointer for the entropy and nonce callbacks
*
* The ownership of the context data remains with the caller,
* i.e., it is the caller's responsibility to keep it available as long
* as it is need by the callbacks and free it after use.
*
* Setting the callback data is allowed only if the drbg has not been
* initialized yet. Otherwise, the operation will fail.
*
* Returns 1 on success, 0 on failure.
*/
int RAND_DRBG_set_callback_data(RAND_DRBG *drbg, void *data)
{
if (EVP_RAND_state(drbg->rand) != EVP_RAND_STATE_UNINITIALISED
|| drbg->parent != NULL)
return 0;
drbg->callback_data = data;
return 1;
}
/* Retrieve the callback data pointer */
void *RAND_DRBG_get_callback_data(RAND_DRBG *drbg)
{
return drbg->callback_data;
}
/*
* Set/initialize |drbg| to be of type |type|, with optional |flags|.
*
* If |type| and |flags| are zero, use the defaults
*
* Returns 1 on success, 0 on failure.
*/
int RAND_DRBG_set(RAND_DRBG *drbg, int type, unsigned int flags)
{
OSSL_PARAM params[6], *p = params;
unsigned int reseed_interval;
time_t reseed_time_interval;
const char *name = NULL;
EVP_RAND *rand;
EVP_RAND_CTX *pctx;
int use_df;
RAND_DRBG_get_entropy_fn get_entropy = drbg->get_entropy;
RAND_DRBG_cleanup_entropy_fn cleanup_entropy = drbg->cleanup_entropy;
RAND_DRBG_get_nonce_fn get_nonce = drbg->get_nonce;
RAND_DRBG_cleanup_nonce_fn cleanup_nonce = drbg->cleanup_nonce;
if (type == 0 && flags == 0) {
type = rand_drbg_type[RAND_DRBG_TYPE_PRIMARY];
flags = rand_drbg_flags[RAND_DRBG_TYPE_PRIMARY];
}
if (drbg->parent == NULL) {
reseed_interval = primary_reseed_interval;
reseed_time_interval = primary_reseed_time_interval;
} else {
reseed_interval = secondary_reseed_interval;
reseed_time_interval = secondary_reseed_time_interval;
}
*p++ = OSSL_PARAM_construct_uint(OSSL_DRBG_PARAM_RESEED_REQUESTS,
&reseed_interval);
*p++ = OSSL_PARAM_construct_time_t(OSSL_DRBG_PARAM_RESEED_TIME_INTERVAL,
&reseed_time_interval);
use_df = (flags & RAND_DRBG_FLAG_CTR_NO_DF) == 0;
*p++ = OSSL_PARAM_construct_int(OSSL_DRBG_PARAM_USE_DF, &use_df);
if (!get_drbg_params(type, flags, &name, p)) {
RANDerr(0, RAND_R_UNSUPPORTED_DRBG_TYPE);
return 0;
}
rand = EVP_RAND_fetch(drbg->libctx, name, NULL);
if (rand == NULL) {
RANDerr(0, RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED);
return 0;
}
EVP_RAND_CTX_free(drbg->rand);
drbg->rand = NULL;
drbg->flags = flags;
drbg->type = type;
pctx = drbg->parent != NULL ? drbg->parent->rand : NULL;
drbg->rand = EVP_RAND_CTX_new(rand, pctx);
EVP_RAND_free(rand);
if (drbg->rand == NULL) {
RANDerr(0, RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED);
goto err;
}
if (!EVP_RAND_set_ctx_params(drbg->rand, params)) {
RANDerr(0, RAND_R_ERROR_INITIALISING_DRBG);
goto err;
}
if (!RAND_DRBG_set_callbacks(drbg,
get_entropy, cleanup_entropy,
get_nonce, cleanup_nonce)) {
RANDerr(0, RAND_R_ERROR_INITIALISING_DRBG);
goto err;
}
return 1;
err:
EVP_RAND_CTX_free(drbg->rand);
drbg->rand = NULL;
drbg->type = 0;
drbg->flags = 0;
return 0;
}
/*
* Set/initialize default |type| and |flag| for new drbg instances.
*
* Returns 1 on success, 0 on failure.
*/
int RAND_DRBG_set_defaults(int type, unsigned int flags)
{
int all;
const char *name;
OSSL_PARAM params[3];
if (!get_drbg_params(type, flags, &name, params)) {
RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS, RAND_R_UNSUPPORTED_DRBG_TYPE);
return 0;
}
if ((flags & ~rand_drbg_used_flags) != 0) {
RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS, RAND_R_UNSUPPORTED_DRBG_FLAGS);
return 0;
}
all = ((flags & RAND_DRBG_TYPE_FLAGS) == 0);
if (all || (flags & RAND_DRBG_FLAG_PRIMARY) != 0) {
rand_drbg_type[RAND_DRBG_TYPE_PRIMARY] = type;
rand_drbg_flags[RAND_DRBG_TYPE_PRIMARY] = flags
| RAND_DRBG_FLAG_PRIMARY;
}
if (all || (flags & RAND_DRBG_FLAG_PUBLIC) != 0) {
rand_drbg_type[RAND_DRBG_TYPE_PUBLIC] = type;
rand_drbg_flags[RAND_DRBG_TYPE_PUBLIC] = flags | RAND_DRBG_FLAG_PUBLIC;
}
if (all || (flags & RAND_DRBG_FLAG_PRIVATE) != 0) {
rand_drbg_type[RAND_DRBG_TYPE_PRIVATE] = type;
rand_drbg_flags[RAND_DRBG_TYPE_PRIVATE] = flags
| RAND_DRBG_FLAG_PRIVATE;
}
return 1;
}
/*
* Allocate memory and initialize a new DRBG.
* The |parent|, if not NULL, will be used as random source for reseeding.
*
* Returns a pointer to the new DRBG instance on success, NULL on failure.
*/
static RAND_DRBG *rand_drbg_new(OPENSSL_CTX *ctx,
int type,
unsigned int flags,
RAND_DRBG *parent)
{
RAND_DRBG *drbg = OPENSSL_zalloc(sizeof(*drbg));
if (drbg == NULL) {
RANDerr(RAND_F_RAND_DRBG_NEW, ERR_R_MALLOC_FAILURE);
return NULL;
}
drbg->libctx = ctx;
drbg->parent = parent;
if (RAND_DRBG_set(drbg, type, flags) == 0)
goto err;
return drbg;
err:
RAND_DRBG_free(drbg);
return NULL;
}
RAND_DRBG *RAND_DRBG_new_ex(OPENSSL_CTX *ctx, int type, unsigned int flags,
RAND_DRBG *parent)
{
return rand_drbg_new(ctx, type, flags, parent);
}
RAND_DRBG *RAND_DRBG_new(int type, unsigned int flags, RAND_DRBG *parent)
{
return RAND_DRBG_new_ex(NULL, type, flags, parent);
}
/*
* Uninstantiate |drbg| and free all memory.
*/
void RAND_DRBG_free(RAND_DRBG *drbg)
{
if (drbg == NULL)
return;
CRYPTO_free_ex_data(CRYPTO_EX_INDEX_RAND_DRBG, drbg, &drbg->ex_data);
EVP_RAND_CTX_free(drbg->rand);
OPENSSL_free(drbg);
}
/*
* Instantiate |drbg|, after it has been initialized. Use |pers| and
* |perslen| as prediction-resistance input.
*
* Requires that drbg->lock is already locked for write, if non-null.
*
* Returns 1 on success, 0 on failure.
*/
int RAND_DRBG_instantiate(RAND_DRBG *drbg,
const unsigned char *pers, size_t perslen)
{
return EVP_RAND_instantiate(drbg->rand, EVP_RAND_strength(drbg->rand), 0,
pers, perslen);
}
/*
* Uninstantiate |drbg|. Must be instantiated before it can be used.
*
* Requires that drbg->lock is already locked for write, if non-null.
*
* Returns 1 on success, 0 on failure.
*/
int RAND_DRBG_uninstantiate(RAND_DRBG *drbg)
{
int index = -1, type, flags;
if (!EVP_RAND_uninstantiate(drbg->rand))
return 0;
/* The reset uses the default values for type and flags */
if (drbg->flags & RAND_DRBG_FLAG_PRIMARY)
index = RAND_DRBG_TYPE_PRIMARY;
else if (drbg->flags & RAND_DRBG_FLAG_PRIVATE)
index = RAND_DRBG_TYPE_PRIVATE;
else if (drbg->flags & RAND_DRBG_FLAG_PUBLIC)
index = RAND_DRBG_TYPE_PUBLIC;
if (index != -1) {
flags = rand_drbg_flags[index];
type = rand_drbg_type[index];
} else {
flags = drbg->flags;
type = drbg->type;
}
return RAND_DRBG_set(drbg, type, flags);
}
/*
* Reseed |drbg|, mixing in the specified data
*
* Requires that drbg->lock is already locked for write, if non-null.
*
* Returns 1 on success, 0 on failure.
*/
int RAND_DRBG_reseed(RAND_DRBG *drbg,
const unsigned char *adin, size_t adinlen,
int prediction_resistance)
{
return EVP_RAND_reseed(drbg->rand, prediction_resistance, NULL, 0,
adin, adinlen);
}
/*
* Generate |outlen| bytes into the buffer at |out|. Reseed if we need
* to or if |prediction_resistance| is set. Additional input can be
* sent in |adin| and |adinlen|.
*
* Requires that drbg->lock is already locked for write, if non-null.
*
* Returns 1 on success, 0 on failure.
*
*/
int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen,
int prediction_resistance,
const unsigned char *adin, size_t adinlen)
{
return EVP_RAND_generate(drbg->rand, out, outlen, 0,
prediction_resistance, adin, adinlen);
}
/*
* Generates |outlen| random bytes and stores them in |out|. It will
* using the given |drbg| to generate the bytes.
*
* Requires that drbg->lock is already locked for write, if non-null.
*
* Returns 1 on success 0 on failure.
*/
int RAND_DRBG_bytes(RAND_DRBG *drbg, unsigned char *out, size_t outlen)
{
return EVP_RAND_generate(drbg->rand, out, outlen, 0, 0, NULL, 0);
}
/* DRBG call back shims */
static int rand_drbg_get_entroy_cb(const OSSL_PARAM *params, OSSL_PARAM *out,
void *vdrbg)
{
RAND_DRBG *drbg = (RAND_DRBG *)vdrbg;
int entropy = 0, prediction_resistance = 0;
size_t min_len = 0, max_len = 2048;
const OSSL_PARAM *p;
OSSL_PARAM *q;
if (drbg->get_entropy == NULL)
return 0;
p = OSSL_PARAM_locate_const(params, OSSL_DRBG_PARAM_ENTROPY_REQUIRED);
if (p == NULL || !OSSL_PARAM_get_int(p, &entropy))
return 0;
p = OSSL_PARAM_locate_const(params, OSSL_DRBG_PARAM_PREDICTION_RESISTANCE);
if (p == NULL || !OSSL_PARAM_get_int(p, &prediction_resistance))
return 0;
p = OSSL_PARAM_locate_const(params, OSSL_DRBG_PARAM_MAX_LENGTH);
if (p == NULL || !OSSL_PARAM_get_size_t(p, &max_len))
return 0;
p = OSSL_PARAM_locate_const(params, OSSL_DRBG_PARAM_MIN_LENGTH);
if (p == NULL || !OSSL_PARAM_get_size_t(p, &min_len))
return 0;
q = OSSL_PARAM_locate(out, OSSL_DRBG_PARAM_RANDOM_DATA);
if (q == NULL || q->data_type != OSSL_PARAM_OCTET_PTR || q->data == NULL)
return 0;
q->return_size = drbg->get_entropy(drbg, (unsigned char **)q->data, entropy,
min_len, max_len, prediction_resistance);
return 1;
}
static int rand_drbg_cleanup_entropy_cb(const OSSL_PARAM *params, void *vdrbg)
{
RAND_DRBG *drbg = (RAND_DRBG *)vdrbg;
const OSSL_PARAM *p;
size_t sz;
if (drbg->cleanup_entropy == NULL)
return 0;
p = OSSL_PARAM_locate_const(params, OSSL_DRBG_PARAM_SIZE);
if (p == NULL || !OSSL_PARAM_get_size_t(p, &sz))
return 0;
p = OSSL_PARAM_locate_const(params, OSSL_DRBG_PARAM_RANDOM_DATA);
if (p == NULL || p->data_type != OSSL_PARAM_OCTET_PTR)
return 0;
drbg->cleanup_entropy(drbg, p->data, sz);
return 1;
}
static int rand_drbg_get_nonce_cb(const OSSL_PARAM *params, OSSL_PARAM *out,
void *vdrbg)
{
RAND_DRBG *drbg = (RAND_DRBG *)vdrbg;
int entropy = 0;
size_t min_len = 0, max_len = 10240;
const OSSL_PARAM *p;
OSSL_PARAM *q;
if (drbg->get_nonce == NULL)
return 0;
p = OSSL_PARAM_locate_const(params, OSSL_DRBG_PARAM_ENTROPY_REQUIRED);
if (p == NULL || !OSSL_PARAM_get_int(p, &entropy))
return 0;
p = OSSL_PARAM_locate_const(params, OSSL_DRBG_PARAM_MAX_LENGTH);
if (p == NULL || !OSSL_PARAM_get_size_t(p, &max_len))
return 0;
p = OSSL_PARAM_locate_const(params, OSSL_DRBG_PARAM_MIN_LENGTH);
if (p == NULL || !OSSL_PARAM_get_size_t(p, &min_len))
return 0;
q = OSSL_PARAM_locate(out, OSSL_DRBG_PARAM_RANDOM_DATA);
if (q == NULL || q->data_type != OSSL_PARAM_OCTET_PTR || q->data == NULL)
return 0;
q->return_size = drbg->get_nonce(drbg, (unsigned char **)q->data, entropy,
min_len, max_len);
return 1;
}
static int rand_drbg_cleanup_nonce_cb(const OSSL_PARAM *params, void *vdrbg)
{
RAND_DRBG *drbg = (RAND_DRBG *)vdrbg;
const OSSL_PARAM *p;
size_t sz;
if (drbg->cleanup_nonce == NULL)
return 0;
p = OSSL_PARAM_locate_const(params, OSSL_DRBG_PARAM_SIZE);
if (p == NULL || !OSSL_PARAM_get_size_t(p, &sz))
return 0;
p = OSSL_PARAM_locate_const(params, OSSL_DRBG_PARAM_RANDOM_DATA);
if (p == NULL || p->data_type != OSSL_PARAM_OCTET_PTR)
return 0;
drbg->cleanup_nonce(drbg, p->data, sz);
return 1;
}
/*
* Set the RAND_DRBG callbacks for obtaining entropy and nonce.
*
* Setting the callbacks is allowed only if the drbg has not been
* initialized yet. Otherwise, the operation will fail.
*
* Returns 1 on success, 0 on failure.
*/
int RAND_DRBG_set_callbacks(RAND_DRBG *drbg,
RAND_DRBG_get_entropy_fn get_entropy,
RAND_DRBG_cleanup_entropy_fn cleanup_entropy,
RAND_DRBG_get_nonce_fn get_nonce,
RAND_DRBG_cleanup_nonce_fn cleanup_nonce)
{
EVP_RAND_CTX *rand = drbg->rand;
OSSL_INOUT_CALLBACK *g_ent = NULL, *g_nonce = NULL;
OSSL_CALLBACK *c_ent = NULL, *c_nonce = NULL;
if (get_entropy != NULL) {
g_ent = &rand_drbg_get_entroy_cb;
c_ent = &rand_drbg_cleanup_entropy_cb;
}
if (get_nonce != NULL) {
g_nonce = rand_drbg_get_nonce_cb;
c_nonce = rand_drbg_cleanup_nonce_cb;
}
if (!EVP_RAND_set_callbacks(rand, g_ent, c_ent, g_nonce, c_nonce, drbg))
return 0;
drbg->get_entropy = g_ent != NULL ? get_entropy : NULL;
drbg->cleanup_entropy = c_ent != NULL ? cleanup_entropy : NULL;
drbg->get_nonce = g_nonce != NULL ? get_nonce : NULL;
drbg->cleanup_nonce = c_nonce != NULL ? cleanup_nonce : NULL;
return 1;
}
/*
* Set the reseed interval.
*
* The drbg will reseed automatically whenever the number of generate
* requests exceeds the given reseed interval. If the reseed interval
* is 0, then this feature is disabled.
*
* Returns 1 on success, 0 on failure.
*/
int RAND_DRBG_set_reseed_interval(RAND_DRBG *drbg, unsigned int interval)
{
OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END };
if (interval > MAX_RESEED_INTERVAL)
return 0;
params[0] = OSSL_PARAM_construct_uint(OSSL_DRBG_PARAM_RESEED_REQUESTS,
&interval);
return EVP_RAND_set_ctx_params(drbg->rand, params);
}
/*
* Set the reseed time interval.
*
* The drbg will reseed automatically whenever the time elapsed since
* the last reseeding exceeds the given reseed time interval. For safety,
* a reseeding will also occur if the clock has been reset to a smaller
* value.
*
* Returns 1 on success, 0 on failure.
*/
int RAND_DRBG_set_reseed_time_interval(RAND_DRBG *drbg, time_t interval)
{
OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END };
if (interval > MAX_RESEED_TIME_INTERVAL)
return 0;
params[0] =
OSSL_PARAM_construct_time_t(OSSL_DRBG_PARAM_RESEED_TIME_INTERVAL,
&interval);
return EVP_RAND_set_ctx_params(drbg->rand, params);
}
/*
* Set the default values for reseed (time) intervals of new DRBG instances
*
* The default values can be set independently for primary DRBG instances
* (without a parent) and secondary DRBG instances (with parent).
*
* Returns 1 on success, 0 on failure.
*/
int RAND_DRBG_set_reseed_defaults(
unsigned int _primary_reseed_interval,
unsigned int _secondary_reseed_interval,
time_t _primary_reseed_time_interval,
time_t _secondary_reseed_time_interval
)
{
if (_primary_reseed_interval > MAX_RESEED_INTERVAL
|| _secondary_reseed_interval > MAX_RESEED_INTERVAL)
return 0;
if (_primary_reseed_time_interval > MAX_RESEED_TIME_INTERVAL
|| _secondary_reseed_time_interval > MAX_RESEED_TIME_INTERVAL)
return 0;
primary_reseed_interval = _primary_reseed_interval;
secondary_reseed_interval = _secondary_reseed_interval;
primary_reseed_time_interval = _primary_reseed_time_interval;
secondary_reseed_time_interval = _secondary_reseed_time_interval;
return 1;
}
/*
* Get and set the EXDATA
*/
int RAND_DRBG_set_ex_data(RAND_DRBG *drbg, int idx, void *arg)
{
return CRYPTO_set_ex_data(&drbg->ex_data, idx, arg);
}
void *RAND_DRBG_get_ex_data(const RAND_DRBG *drbg, int idx)
{
return CRYPTO_get_ex_data(&drbg->ex_data, idx);
}
/*
* The following functions provide a RAND_METHOD that works on the
* global DRBG. They lock.
*/
/*
* Allocates a new global DRBG on the secure heap (if enabled) and
* initializes it with default settings.
*
* Returns a pointer to the new DRBG instance on success, NULL on failure.
*/
static RAND_DRBG *drbg_setup(OPENSSL_CTX *ctx, RAND_DRBG *parent, int drbg_type)
{
RAND_DRBG *drbg;
drbg = RAND_DRBG_new_ex(ctx, rand_drbg_type[drbg_type],
rand_drbg_flags[drbg_type], parent);
if (drbg == NULL)
return NULL;
/* Only the primary DRBG needs to have a lock */
if (parent == NULL && EVP_RAND_enable_locking(drbg->rand) == 0)
goto err;
/*
* Ignore instantiation error to support just-in-time instantiation.
*
* The state of the drbg will be checked in RAND_DRBG_generate() and
* an automatic recovery is attempted.
*/
(void)RAND_DRBG_instantiate(drbg, NULL, 0);
return drbg;
err:
RAND_DRBG_free(drbg);
return NULL;
}
static void drbg_delete_thread_state(void *arg)
{
OPENSSL_CTX *ctx = arg;
DRBG_GLOBAL *dgbl = drbg_get_global(ctx);
RAND_DRBG *drbg;
if (dgbl == NULL)
return;
drbg = CRYPTO_THREAD_get_local(&dgbl->public_drbg);
CRYPTO_THREAD_set_local(&dgbl->public_drbg, NULL);
RAND_DRBG_free(drbg);
drbg = CRYPTO_THREAD_get_local(&dgbl->private_drbg);
CRYPTO_THREAD_set_local(&dgbl->private_drbg, NULL);
RAND_DRBG_free(drbg);
}
/* Implements the default OpenSSL RAND_bytes() method */
static int drbg_bytes(unsigned char *out, int count)
{
int ret;
RAND_DRBG *drbg = RAND_DRBG_get0_public();
if (drbg == NULL)
return 0;
ret = RAND_DRBG_bytes(drbg, out, count);
return ret;
}
/* Implements the default OpenSSL RAND_add() method */
static int drbg_add(const void *buf, int num, double randomness)
{
RAND_DRBG *drbg = RAND_DRBG_get0_master();
if (drbg == NULL || num <= 0)
return 0;
return EVP_RAND_reseed(drbg->rand, 0, NULL, 0, buf, num);
}
/* Implements the default OpenSSL RAND_seed() method */
static int drbg_seed(const void *buf, int num)
{
return drbg_add(buf, num, num);
}
/* Implements the default OpenSSL RAND_status() method */
static int drbg_status(void)
{
int ret;
RAND_DRBG *drbg = RAND_DRBG_get0_master();
if (drbg == NULL)
return 0;
ret = EVP_RAND_state(drbg->rand) == EVP_RAND_STATE_READY ? 1 : 0;
return ret;
}
int RAND_DRBG_verify_zeroization(RAND_DRBG *drbg)
{
return EVP_RAND_verify_zeroization(drbg->rand);
}
/*
* Get the primary DRBG.
* Returns pointer to the DRBG on success, NULL on failure.
*
*/
RAND_DRBG *OPENSSL_CTX_get0_primary_drbg(OPENSSL_CTX *ctx)
{
DRBG_GLOBAL *dgbl = drbg_get_global(ctx);
if (dgbl == NULL)
return NULL;
if (dgbl->primary_drbg == NULL) {
if (!CRYPTO_THREAD_write_lock(dgbl->lock))
return NULL;
if (dgbl->primary_drbg == NULL)
dgbl->primary_drbg = drbg_setup(ctx, NULL, RAND_DRBG_TYPE_PRIMARY);
CRYPTO_THREAD_unlock(dgbl->lock);
}
return dgbl->primary_drbg;
}
RAND_DRBG *RAND_DRBG_get0_master(void)
{
return OPENSSL_CTX_get0_primary_drbg(NULL);
}
/*
* Get the public DRBG.
* Returns pointer to the DRBG on success, NULL on failure.
*/
RAND_DRBG *OPENSSL_CTX_get0_public_drbg(OPENSSL_CTX *ctx)
{
DRBG_GLOBAL *dgbl = drbg_get_global(ctx);
RAND_DRBG *drbg, *primary;
if (dgbl == NULL)
return NULL;
drbg = CRYPTO_THREAD_get_local(&dgbl->public_drbg);
if (drbg == NULL) {
primary = OPENSSL_CTX_get0_primary_drbg(ctx);
if (primary == NULL)
return NULL;
ctx = openssl_ctx_get_concrete(ctx);
/*
* If the private_drbg is also NULL then this is the first time we've
* used this thread.
*/
if (CRYPTO_THREAD_get_local(&dgbl->private_drbg) == NULL
&& !ossl_init_thread_start(NULL, ctx, drbg_delete_thread_state))
return NULL;
drbg = drbg_setup(ctx, primary, RAND_DRBG_TYPE_PUBLIC);
CRYPTO_THREAD_set_local(&dgbl->public_drbg, drbg);
}
return drbg;
}
RAND_DRBG *RAND_DRBG_get0_public(void)
{
return OPENSSL_CTX_get0_public_drbg(NULL);
}
/*
* Get the private DRBG.
* Returns pointer to the DRBG on success, NULL on failure.
*/
RAND_DRBG *OPENSSL_CTX_get0_private_drbg(OPENSSL_CTX *ctx)
{
DRBG_GLOBAL *dgbl = drbg_get_global(ctx);
RAND_DRBG *drbg, *primary;
if (dgbl == NULL)
return NULL;
drbg = CRYPTO_THREAD_get_local(&dgbl->private_drbg);
if (drbg == NULL) {
primary = OPENSSL_CTX_get0_primary_drbg(ctx);
if (primary == NULL)
return NULL;
ctx = openssl_ctx_get_concrete(ctx);
/*
* If the public_drbg is also NULL then this is the first time we've
* used this thread.
*/
if (CRYPTO_THREAD_get_local(&dgbl->public_drbg) == NULL
&& !ossl_init_thread_start(NULL, ctx, drbg_delete_thread_state))
return NULL;
drbg = drbg_setup(ctx, primary, RAND_DRBG_TYPE_PRIVATE);
CRYPTO_THREAD_set_local(&dgbl->private_drbg, drbg);
}
return drbg;
}
RAND_DRBG *RAND_DRBG_get0_private(void)
{
return OPENSSL_CTX_get0_private_drbg(NULL);
}
RAND_METHOD rand_meth = {
drbg_seed,
drbg_bytes,
NULL,
drbg_add,
drbg_bytes,
drbg_status
};
RAND_METHOD *RAND_OpenSSL(void)
{
#ifndef FIPS_MODULE
return &rand_meth;
#else
return NULL;
#endif
}
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