/*
- * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
#include <openssl/engine.h>
#include "internal/thread_once.h"
#include "rand_lcl.h"
+#include "e_os.h"
#ifndef OPENSSL_NO_ENGINE
/* non-NULL if default_RAND_meth is ENGINE-provided */
static CRYPTO_RWLOCK *rand_meth_lock;
static const RAND_METHOD *default_RAND_meth;
static CRYPTO_ONCE rand_init = CRYPTO_ONCE_STATIC_INIT;
-RAND_BYTES_BUFFER rand_bytes;
+
+int rand_fork_count;
+
+static CRYPTO_RWLOCK *rand_nonce_lock;
+static int rand_nonce_count;
+
+static int rand_cleaning_up = 0;
#ifdef OPENSSL_RAND_SEED_RDTSC
/*
* IMPORTANT NOTE: It is not currently possible to use this code
- * because we are not sure about the amount of randomness. Some
- * SP900 tests have been run, but there is internal skepticism.
+ * because we are not sure about the amount of randomness it provides.
+ * Some SP900 tests have been run, but there is internal skepticism.
* So for now this code is not used.
*/
# error "RDTSC enabled? Should not be possible!"
/*
+ * Acquire entropy from high-speed clock
+ *
* Since we get some randomness from the low-order bits of the
- * high-speec clock, it can help. But don't return a status since
- * it's not sufficient to indicate whether or not the seeding was
- * done.
+ * high-speed clock, it can help.
+ *
+ * Returns the total entropy count, if it exceeds the requested
+ * entropy count. Otherwise, returns an entropy count of 0.
*/
-void rand_read_tsc(RAND_poll_fn cb, void *arg)
+size_t rand_acquire_entropy_from_tsc(RAND_POOL *pool)
{
unsigned char c;
int i;
- for (i = 0; i < 10; i++) {
- c = (unsigned char)(OPENSSL_rdtsc() & 0xFF);
- cb(arg, &c, 1, 0.5);
+ if ((OPENSSL_ia32cap_P[0] & (1 << 4)) != 0) {
+ for (i = 0; i < TSC_READ_COUNT; i++) {
+ c = (unsigned char)(OPENSSL_rdtsc() & 0xFF);
+ rand_pool_add(pool, &c, 1, 4);
+ }
}
+ return rand_pool_entropy_available(pool);
}
#endif
#ifdef OPENSSL_RAND_SEED_RDCPU
-size_t OPENSSL_ia32_rdseed(void);
-size_t OPENSSL_ia32_rdrand(void);
+size_t OPENSSL_ia32_rdseed_bytes(unsigned char *buf, size_t len);
+size_t OPENSSL_ia32_rdrand_bytes(unsigned char *buf, size_t len);
extern unsigned int OPENSSL_ia32cap_P[];
-int rand_read_cpu(RAND_poll_fn cb, void *arg)
+/*
+ * Acquire entropy using Intel-specific cpu instructions
+ *
+ * Uses the RDSEED instruction if available, otherwise uses
+ * RDRAND if available.
+ *
+ * For the differences between RDSEED and RDRAND, and why RDSEED
+ * is the preferred choice, see https://goo.gl/oK3KcN
+ *
+ * Returns the total entropy count, if it exceeds the requested
+ * entropy count. Otherwise, returns an entropy count of 0.
+ */
+size_t rand_acquire_entropy_from_cpu(RAND_POOL *pool)
{
- size_t i, s;
-
- /* If RDSEED is available, use that. */
- if ((OPENSSL_ia32cap_P[1] & (1 << 18)) != 0) {
- for (i = 0; i < RANDOMNESS_NEEDED; i += sizeof(s)) {
- s = OPENSSL_ia32_rdseed();
- if (s == 0)
- break;
- cb(arg, &s, (int)sizeof(s), sizeof(s));
- }
- if (i >= RANDOMNESS_NEEDED)
- return 1;
- }
-
- /* Second choice is RDRAND. */
- if ((OPENSSL_ia32cap_P[1] & (1 << (62 - 32))) != 0) {
- for (i = 0; i < RANDOMNESS_NEEDED; i += sizeof(s)) {
- s = OPENSSL_ia32_rdrand();
- if (s == 0)
- break;
- cb(arg, &s, (int)sizeof(s), sizeof(s));
+ size_t bytes_needed;
+ unsigned char *buffer;
+
+ bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
+ if (bytes_needed > 0) {
+ buffer = rand_pool_add_begin(pool, bytes_needed);
+
+ if (buffer != NULL) {
+ /* Whichever comes first, use RDSEED, RDRAND or nothing */
+ if ((OPENSSL_ia32cap_P[2] & (1 << 18)) != 0) {
+ if (OPENSSL_ia32_rdseed_bytes(buffer, bytes_needed)
+ == bytes_needed) {
+ rand_pool_add_end(pool, bytes_needed, 8 * bytes_needed);
+ }
+ } else if ((OPENSSL_ia32cap_P[1] & (1 << (62 - 32))) != 0) {
+ if (OPENSSL_ia32_rdrand_bytes(buffer, bytes_needed)
+ == bytes_needed) {
+ rand_pool_add_end(pool, bytes_needed, 8 * bytes_needed);
+ }
+ } else {
+ rand_pool_add_end(pool, 0, 0);
+ }
}
- if (i >= RANDOMNESS_NEEDED)
- return 1;
}
- return 0;
+ return rand_pool_entropy_available(pool);
}
#endif
/*
- * DRBG has two sets of callbacks; we only discuss the "entropy" one
- * here. When the DRBG needs additional randomness bits (called entropy
- * in the NIST document), it calls the get_entropy callback which fills in
- * a pointer and returns the number of bytes. When the DRBG is finished with
- * the buffer, it calls the cleanup_entropy callback, with the value of
- * the buffer that the get_entropy callback filled in.
+ * Implements the get_entropy() callback (see RAND_DRBG_set_callbacks())
+ *
+ * If the DRBG has a parent, then the required amount of entropy input
+ * is fetched using the parent's RAND_DRBG_generate().
*
- * Get entropy from the system, via RAND_poll if needed. The |entropy|
- * is the bits of randomness required, and is expected to fit into a buffer
- * of |min_len|..|max__len| size. We assume we're getting high-quality
- * randomness from the system, and that |min_len| bytes will do.
+ * Otherwise, the entropy is polled from the system entropy sources
+ * using rand_pool_acquire_entropy().
+ *
+ * If a random pool has been added to the DRBG using RAND_add(), then
+ * its entropy will be used up first.
*/
-size_t drbg_entropy_from_system(RAND_DRBG *drbg,
- unsigned char **pout,
- int entropy, size_t min_len, size_t max_len)
+size_t rand_drbg_get_entropy(RAND_DRBG *drbg,
+ unsigned char **pout,
+ int entropy, size_t min_len, size_t max_len,
+ int prediction_resistance)
{
- int i;
-
-
- if (min_len > (size_t)drbg->size) {
- /* Should not happen. See comment near RANDOMNESS_NEEDED. */
- min_len = drbg->size;
+ size_t ret = 0;
+ size_t entropy_available = 0;
+ RAND_POOL *pool;
+
+ if (drbg->parent && drbg->strength > drbg->parent->strength) {
+ /*
+ * We currently don't support the algorithm from NIST SP 800-90C
+ * 10.1.2 to use a weaker DRBG as source
+ */
+ RANDerr(RAND_F_RAND_DRBG_GET_ENTROPY, RAND_R_PARENT_STRENGTH_TOO_WEAK);
+ return 0;
}
- if (rand_drbg.filled) {
- /* Re-use what we have. */
- *pout = drbg->randomness;
- return drbg->size;
+ if (drbg->pool != NULL) {
+ pool = drbg->pool;
+ pool->entropy_requested = entropy;
+ } else {
+ pool = rand_pool_new(entropy, min_len, max_len);
+ if (pool == NULL)
+ return 0;
}
- /* If we don't have enough, try to get more. */
- CRYPTO_THREAD_write_lock(rand_bytes.lock);
- for (i = RAND_POLL_RETRIES; rand_bytes.curr < min_len && --i >= 0; ) {
- CRYPTO_THREAD_unlock(rand_bytes.lock);
- RAND_poll();
- CRYPTO_THREAD_write_lock(rand_bytes.lock);
+ if (drbg->parent) {
+ size_t bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
+ unsigned char *buffer = rand_pool_add_begin(pool, bytes_needed);
+
+ if (buffer != NULL) {
+ size_t bytes = 0;
+
+ /*
+ * Get random from parent, include our state as additional input.
+ * Our lock is already held, but we need to lock our parent before
+ * generating bits from it. (Note: taking the lock will be a no-op
+ * if locking if drbg->parent->lock == NULL.)
+ */
+ rand_drbg_lock(drbg->parent);
+ if (RAND_DRBG_generate(drbg->parent,
+ buffer, bytes_needed,
+ prediction_resistance,
+ NULL, 0) != 0)
+ bytes = bytes_needed;
+ drbg->reseed_next_counter
+ = tsan_load(&drbg->parent->reseed_prop_counter);
+ rand_drbg_unlock(drbg->parent);
+
+ rand_pool_add_end(pool, bytes, 8 * bytes);
+ entropy_available = rand_pool_entropy_available(pool);
+ }
+
+ } else {
+ if (prediction_resistance) {
+ /*
+ * We don't have any entropy sources that comply with the NIST
+ * standard to provide prediction resistance (see NIST SP 800-90C,
+ * Section 5.4).
+ */
+ RANDerr(RAND_F_RAND_DRBG_GET_ENTROPY,
+ RAND_R_PREDICTION_RESISTANCE_NOT_SUPPORTED);
+ goto err;
+ }
+
+ /* Get entropy by polling system entropy sources. */
+ entropy_available = rand_pool_acquire_entropy(pool);
}
- /* Get desired amount, but no more than we have. */
- if (min_len > rand_bytes.curr)
- min_len = rand_bytes.curr;
- if (min_len != 0) {
- memcpy(drbg->randomness, rand_bytes.buff, min_len);
- rand_drbg.filled = 1;
- /* Update amount left and shift it down. */
- rand_bytes.curr -= min_len;
- if (rand_bytes.curr != 0)
- memmove(rand_bytes.buff, &rand_bytes.buff[min_len], rand_bytes.curr);
+ if (entropy_available > 0) {
+ ret = rand_pool_length(pool);
+ *pout = rand_pool_detach(pool);
}
- CRYPTO_THREAD_unlock(rand_bytes.lock);
- *pout = drbg->randomness;
- return min_len;
+
+ err:
+ /* we need to reset drbg->pool in the error case */
+ if (ret == 0 && drbg->pool != NULL)
+ drbg->pool = NULL;
+
+ rand_pool_free(pool);
+ return ret;
}
-size_t drbg_entropy_from_parent(RAND_DRBG *drbg,
- unsigned char **pout,
- int entropy, size_t min_len, size_t max_len)
+/*
+ * Implements the cleanup_entropy() callback (see RAND_DRBG_set_callbacks())
+ *
+ */
+void rand_drbg_cleanup_entropy(RAND_DRBG *drbg,
+ unsigned char *out, size_t outlen)
{
- int st;
+ if (drbg->pool == NULL)
+ OPENSSL_secure_clear_free(out, outlen);
+ else
+ drbg->pool = NULL;
+}
- if (min_len > (size_t)drbg->size) {
- /* Should not happen. See comment near RANDOMNESS_NEEDED. */
- min_len = drbg->size;
- }
- /* Get random from parent, include our state as additional input. */
- st = RAND_DRBG_generate(drbg->parent, drbg->randomness, min_len, 0,
- (unsigned char *)drbg, sizeof(*drbg));
- if (st == 0)
+/*
+ * Implements the get_nonce() callback (see RAND_DRBG_set_callbacks())
+ *
+ */
+size_t rand_drbg_get_nonce(RAND_DRBG *drbg,
+ unsigned char **pout,
+ int entropy, size_t min_len, size_t max_len)
+{
+ size_t ret = 0;
+ RAND_POOL *pool;
+
+ struct {
+ void * instance;
+ int count;
+ } data = { 0 };
+
+ pool = rand_pool_new(0, min_len, max_len);
+ if (pool == NULL)
return 0;
- drbg->filled = 1;
- *pout = drbg->randomness;
- return min_len;
+
+ if (rand_pool_add_nonce_data(pool) == 0)
+ goto err;
+
+ data.instance = drbg;
+ CRYPTO_atomic_add(&rand_nonce_count, 1, &data.count, rand_nonce_lock);
+
+ if (rand_pool_add(pool, (unsigned char *)&data, sizeof(data), 0) == 0)
+ goto err;
+
+ ret = rand_pool_length(pool);
+ *pout = rand_pool_detach(pool);
+
+ err:
+ rand_pool_free(pool);
+
+ return ret;
}
-void drbg_release_entropy(RAND_DRBG *drbg, unsigned char *out)
+/*
+ * Implements the cleanup_nonce() callback (see RAND_DRBG_set_callbacks())
+ *
+ */
+void rand_drbg_cleanup_nonce(RAND_DRBG *drbg,
+ unsigned char *out, size_t outlen)
{
- drbg->filled = 0;
- OPENSSL_cleanse(drbg->randomness, drbg->size);
+ OPENSSL_secure_clear_free(out, outlen);
}
-
/*
- * Set up a global DRBG.
+ * Generate additional data that can be used for the drbg. The data does
+ * not need to contain entropy, but it's useful if it contains at least
+ * some bits that are unpredictable.
+ *
+ * Returns 0 on failure.
+ *
+ * On success it allocates a buffer at |*pout| and returns the length of
+ * the data. The buffer should get freed using OPENSSL_secure_clear_free().
*/
-static int setup_drbg(RAND_DRBG *drbg)
-{
- int ret = 1;
-
- drbg->lock = CRYPTO_THREAD_lock_new();
- ret &= drbg->lock != NULL;
- drbg->size = RANDOMNESS_NEEDED;
- drbg->randomness = OPENSSL_malloc(drbg->size);
- ret &= drbg->randomness != NULL;
- /* If you change these parameters, see RANDOMNESS_NEEDED */
- ret &= RAND_DRBG_set(drbg,
- NID_aes_128_ctr, RAND_DRBG_FLAG_CTR_USE_DF) == 1;
- ret &= RAND_DRBG_set_callbacks(drbg, drbg_entropy_from_system,
- drbg_release_entropy, NULL, NULL) == 1;
+size_t rand_drbg_get_additional_data(unsigned char **pout, size_t max_len)
+{
+ size_t ret = 0;
+ RAND_POOL *pool;
+
+ pool = rand_pool_new(0, 0, max_len);
+ if (pool == NULL)
+ return 0;
+
+ if (rand_pool_add_additional_data(pool) == 0)
+ goto err;
+
+ ret = rand_pool_length(pool);
+ *pout = rand_pool_detach(pool);
+
+ err:
+ rand_pool_free(pool);
+
return ret;
}
-static void free_drbg(RAND_DRBG *drbg)
+void rand_drbg_cleanup_additional_data(unsigned char *out, size_t outlen)
{
- CRYPTO_THREAD_lock_free(drbg->lock);
- OPENSSL_clear_free(drbg->randomness, drbg->size);
- RAND_DRBG_uninstantiate(drbg);
+ OPENSSL_secure_clear_free(out, outlen);
}
-DEFINE_RUN_ONCE_STATIC(do_rand_init)
+void rand_fork(void)
{
- int ret = 1;
+ rand_fork_count++;
+}
+DEFINE_RUN_ONCE_STATIC(do_rand_init)
+{
#ifndef OPENSSL_NO_ENGINE
rand_engine_lock = CRYPTO_THREAD_lock_new();
- ret &= rand_engine_lock != NULL;
+ if (rand_engine_lock == NULL)
+ return 0;
#endif
+
rand_meth_lock = CRYPTO_THREAD_lock_new();
- ret &= rand_meth_lock != NULL;
-
- rand_bytes.lock = CRYPTO_THREAD_lock_new();
- ret &= rand_bytes.lock != NULL;
- rand_bytes.curr = 0;
- rand_bytes.size = MAX_RANDOMNESS_HELD;
- /* TODO: Should this be secure malloc? */
- rand_bytes.buff = malloc(rand_bytes.size);
-
- ret &= rand_bytes.buff != NULL;
- ret &= setup_drbg(&rand_drbg);
- ret &= setup_drbg(&priv_drbg);
- return ret;
-}
+ if (rand_meth_lock == NULL)
+ goto err1;
+
+ rand_nonce_lock = CRYPTO_THREAD_lock_new();
+ if (rand_nonce_lock == NULL)
+ goto err2;
+ if (!rand_cleaning_up && !rand_pool_init())
+ goto err3;
+
+ return 1;
+
+err3:
+ rand_pool_cleanup();
+err2:
+ CRYPTO_THREAD_lock_free(rand_meth_lock);
+ rand_meth_lock = NULL;
+err1:
+#ifndef OPENSSL_NO_ENGINE
+ CRYPTO_THREAD_lock_free(rand_engine_lock);
+ rand_engine_lock = NULL;
+#endif
+ return 0;
+}
void rand_cleanup_int(void)
{
const RAND_METHOD *meth = default_RAND_meth;
+ rand_cleaning_up = 1;
+
if (meth != NULL && meth->cleanup != NULL)
meth->cleanup();
RAND_set_rand_method(NULL);
+ rand_pool_cleanup();
#ifndef OPENSSL_NO_ENGINE
CRYPTO_THREAD_lock_free(rand_engine_lock);
+ rand_engine_lock = NULL;
#endif
CRYPTO_THREAD_lock_free(rand_meth_lock);
- CRYPTO_THREAD_lock_free(rand_bytes.lock);
- OPENSSL_clear_free(rand_bytes.buff, rand_bytes.size);
- free_drbg(&rand_drbg);
- free_drbg(&priv_drbg);
+ rand_meth_lock = NULL;
+ CRYPTO_THREAD_lock_free(rand_nonce_lock);
+ rand_nonce_lock = NULL;
}
/*
- * RAND_poll_ex() gets a function pointer to call when it has random bytes.
- * RAND_poll() sets the function pointer to be a wrapper that calls RAND_add().
+ * RAND_close_seed_files() ensures that any seed file decriptors are
+ * closed after use.
*/
-static void call_rand_add(void* arg, const void *buf, int num, double r)
+void RAND_keep_random_devices_open(int keep)
{
- RAND_add(buf, num, r);
+ rand_pool_keep_random_devices_open(keep);
}
+/*
+ * RAND_poll() reseeds the default RNG using random input
+ *
+ * The random input is obtained from polling various entropy
+ * sources which depend on the operating system and are
+ * configurable via the --with-rand-seed configure option.
+ */
int RAND_poll(void)
{
- return RAND_poll_ex(call_rand_add, NULL);
+ int ret = 0;
+
+ RAND_POOL *pool = NULL;
+
+ const RAND_METHOD *meth = RAND_get_rand_method();
+
+ if (meth == RAND_OpenSSL()) {
+ /* fill random pool and seed the master DRBG */
+ RAND_DRBG *drbg = RAND_DRBG_get0_master();
+
+ if (drbg == NULL)
+ return 0;
+
+ rand_drbg_lock(drbg);
+ ret = rand_drbg_restart(drbg, NULL, 0, 0);
+ rand_drbg_unlock(drbg);
+
+ return ret;
+
+ } else {
+ /* fill random pool and seed the current legacy RNG */
+ pool = rand_pool_new(RAND_DRBG_STRENGTH,
+ RAND_DRBG_STRENGTH / 8,
+ RAND_POOL_MAX_LENGTH);
+ if (pool == NULL)
+ return 0;
+
+ if (rand_pool_acquire_entropy(pool) == 0)
+ goto err;
+
+ if (meth->add == NULL
+ || meth->add(rand_pool_buffer(pool),
+ rand_pool_length(pool),
+ (rand_pool_entropy(pool) / 8.0)) == 0)
+ goto err;
+
+ ret = 1;
+ }
+
+err:
+ rand_pool_free(pool);
+ return ret;
+}
+
+/*
+ * Allocate memory and initialize a new random pool
+ */
+
+RAND_POOL *rand_pool_new(int entropy_requested, size_t min_len, size_t max_len)
+{
+ RAND_POOL *pool = OPENSSL_zalloc(sizeof(*pool));
+
+ if (pool == NULL) {
+ RANDerr(RAND_F_RAND_POOL_NEW, ERR_R_MALLOC_FAILURE);
+ return NULL;
+ }
+
+ pool->min_len = min_len;
+ pool->max_len = (max_len > RAND_POOL_MAX_LENGTH) ?
+ RAND_POOL_MAX_LENGTH : max_len;
+
+ pool->buffer = OPENSSL_secure_zalloc(pool->max_len);
+ if (pool->buffer == NULL) {
+ RANDerr(RAND_F_RAND_POOL_NEW, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
+
+ pool->entropy_requested = entropy_requested;
+
+ return pool;
+
+err:
+ OPENSSL_free(pool);
+ return NULL;
+}
+
+/*
+ * Attach new random pool to the given buffer
+ *
+ * This function is intended to be used only for feeding random data
+ * provided by RAND_add() and RAND_seed() into the <master> DRBG.
+ */
+RAND_POOL *rand_pool_attach(const unsigned char *buffer, size_t len,
+ size_t entropy)
+{
+ RAND_POOL *pool = OPENSSL_zalloc(sizeof(*pool));
+
+ if (pool == NULL) {
+ RANDerr(RAND_F_RAND_POOL_ATTACH, ERR_R_MALLOC_FAILURE);
+ return NULL;
+ }
+
+ /*
+ * The const needs to be cast away, but attached buffers will not be
+ * modified (in contrary to allocated buffers which are zeroed and
+ * freed in the end).
+ */
+ pool->buffer = (unsigned char *) buffer;
+ pool->len = len;
+
+ pool->attached = 1;
+
+ pool->min_len = pool->max_len = pool->len;
+ pool->entropy = entropy;
+
+ return pool;
+}
+
+/*
+ * Free |pool|, securely erasing its buffer.
+ */
+void rand_pool_free(RAND_POOL *pool)
+{
+ if (pool == NULL)
+ return;
+
+ /*
+ * Although it would be advisable from a cryptographical viewpoint,
+ * we are not allowed to clear attached buffers, since they are passed
+ * to rand_pool_attach() as `const unsigned char*`.
+ * (see corresponding comment in rand_pool_attach()).
+ */
+ if (!pool->attached)
+ OPENSSL_secure_clear_free(pool->buffer, pool->max_len);
+ OPENSSL_free(pool);
+}
+
+/*
+ * Return the |pool|'s buffer to the caller (readonly).
+ */
+const unsigned char *rand_pool_buffer(RAND_POOL *pool)
+{
+ return pool->buffer;
+}
+
+/*
+ * Return the |pool|'s entropy to the caller.
+ */
+size_t rand_pool_entropy(RAND_POOL *pool)
+{
+ return pool->entropy;
+}
+
+/*
+ * Return the |pool|'s buffer length to the caller.
+ */
+size_t rand_pool_length(RAND_POOL *pool)
+{
+ return pool->len;
+}
+
+/*
+ * Detach the |pool| buffer and return it to the caller.
+ * It's the responsibility of the caller to free the buffer
+ * using OPENSSL_secure_clear_free().
+ */
+unsigned char *rand_pool_detach(RAND_POOL *pool)
+{
+ unsigned char *ret = pool->buffer;
+ pool->buffer = NULL;
+ return ret;
+}
+
+
+/*
+ * If |entropy_factor| bits contain 1 bit of entropy, how many bytes does one
+ * need to obtain at least |bits| bits of entropy?
+ */
+#define ENTROPY_TO_BYTES(bits, entropy_factor) \
+ (((bits) * (entropy_factor) + 7) / 8)
+
+
+/*
+ * Checks whether the |pool|'s entropy is available to the caller.
+ * This is the case when entropy count and buffer length are high enough.
+ * Returns
+ *
+ * |entropy| if the entropy count and buffer size is large enough
+ * 0 otherwise
+ */
+size_t rand_pool_entropy_available(RAND_POOL *pool)
+{
+ if (pool->entropy < pool->entropy_requested)
+ return 0;
+
+ if (pool->len < pool->min_len)
+ return 0;
+
+ return pool->entropy;
+}
+
+/*
+ * Returns the (remaining) amount of entropy needed to fill
+ * the random pool.
+ */
+
+size_t rand_pool_entropy_needed(RAND_POOL *pool)
+{
+ if (pool->entropy < pool->entropy_requested)
+ return pool->entropy_requested - pool->entropy;
+
+ return 0;
+}
+
+/*
+ * Returns the number of bytes needed to fill the pool, assuming
+ * the input has 1 / |entropy_factor| entropy bits per data bit.
+ * In case of an error, 0 is returned.
+ */
+
+size_t rand_pool_bytes_needed(RAND_POOL *pool, unsigned int entropy_factor)
+{
+ size_t bytes_needed;
+ size_t entropy_needed = rand_pool_entropy_needed(pool);
+
+ if (entropy_factor < 1) {
+ RANDerr(RAND_F_RAND_POOL_BYTES_NEEDED, RAND_R_ARGUMENT_OUT_OF_RANGE);
+ return 0;
+ }
+
+ bytes_needed = ENTROPY_TO_BYTES(entropy_needed, entropy_factor);
+
+ if (bytes_needed > pool->max_len - pool->len) {
+ /* not enough space left */
+ RANDerr(RAND_F_RAND_POOL_BYTES_NEEDED, RAND_R_RANDOM_POOL_OVERFLOW);
+ return 0;
+ }
+
+ if (pool->len < pool->min_len &&
+ bytes_needed < pool->min_len - pool->len)
+ /* to meet the min_len requirement */
+ bytes_needed = pool->min_len - pool->len;
+
+ return bytes_needed;
+}
+
+/* Returns the remaining number of bytes available */
+size_t rand_pool_bytes_remaining(RAND_POOL *pool)
+{
+ return pool->max_len - pool->len;
+}
+
+/*
+ * Add random bytes to the random pool.
+ *
+ * It is expected that the |buffer| contains |len| bytes of
+ * random input which contains at least |entropy| bits of
+ * randomness.
+ *
+ * Returns 1 if the added amount is adequate, otherwise 0
+ */
+int rand_pool_add(RAND_POOL *pool,
+ const unsigned char *buffer, size_t len, size_t entropy)
+{
+ if (len > pool->max_len - pool->len) {
+ RANDerr(RAND_F_RAND_POOL_ADD, RAND_R_ENTROPY_INPUT_TOO_LONG);
+ return 0;
+ }
+
+ if (len > 0) {
+ memcpy(pool->buffer + pool->len, buffer, len);
+ pool->len += len;
+ pool->entropy += entropy;
+ }
+
+ return 1;
+}
+
+/*
+ * Start to add random bytes to the random pool in-place.
+ *
+ * Reserves the next |len| bytes for adding random bytes in-place
+ * and returns a pointer to the buffer.
+ * The caller is allowed to copy up to |len| bytes into the buffer.
+ * If |len| == 0 this is considered a no-op and a NULL pointer
+ * is returned without producing an error message.
+ *
+ * After updating the buffer, rand_pool_add_end() needs to be called
+ * to finish the udpate operation (see next comment).
+ */
+unsigned char *rand_pool_add_begin(RAND_POOL *pool, size_t len)
+{
+ if (len == 0)
+ return NULL;
+
+ if (len > pool->max_len - pool->len) {
+ RANDerr(RAND_F_RAND_POOL_ADD_BEGIN, RAND_R_RANDOM_POOL_OVERFLOW);
+ return NULL;
+ }
+
+ return pool->buffer + pool->len;
+}
+
+/*
+ * Finish to add random bytes to the random pool in-place.
+ *
+ * Finishes an in-place update of the random pool started by
+ * rand_pool_add_begin() (see previous comment).
+ * It is expected that |len| bytes of random input have been added
+ * to the buffer which contain at least |entropy| bits of randomness.
+ * It is allowed to add less bytes than originally reserved.
+ */
+int rand_pool_add_end(RAND_POOL *pool, size_t len, size_t entropy)
+{
+ if (len > pool->max_len - pool->len) {
+ RANDerr(RAND_F_RAND_POOL_ADD_END, RAND_R_RANDOM_POOL_OVERFLOW);
+ return 0;
+ }
+
+ if (len > 0) {
+ pool->len += len;
+ pool->entropy += entropy;
+ }
+
+ return 1;
}
int RAND_set_rand_method(const RAND_METHOD *meth)
int RAND_priv_bytes(unsigned char *buf, int num)
{
const RAND_METHOD *meth = RAND_get_rand_method();
+ RAND_DRBG *drbg;
+ int ret;
if (meth != RAND_OpenSSL())
return RAND_bytes(buf, num);
- if (priv_drbg.state == DRBG_UNINITIALISED
- && RAND_DRBG_instantiate(&priv_drbg, NULL, 0) == 0)
+ drbg = RAND_DRBG_get0_private();
+ if (drbg == NULL)
return 0;
- return RAND_DRBG_generate(&priv_drbg, buf, num, 0, NULL, 0);
+ ret = RAND_DRBG_bytes(drbg, buf, num);
+ return ret;
}
int RAND_bytes(unsigned char *buf, int num)
projects / openssl.git / blobdiff