-#endif /* FIPS_MODULE */
-
-#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 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-speed clock, it can help.
- *
- * 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_tsc(RAND_POOL *pool)
-{
- unsigned char c;
- int i;
-
- 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_bytes(unsigned char *buf, size_t len);
-size_t OPENSSL_ia32_rdrand_bytes(unsigned char *buf, size_t len);
-
-/*
- * 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 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);
- }
- }
- }
-
- return rand_pool_entropy_available(pool);
-}
-#endif
-
-#if 0
-/*
- * 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().
- *
- * 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 rand_drbg_get_entropy(RAND_DRBG *drbg,
- unsigned char **pout,
- int entropy, size_t min_len, size_t max_len,
- int prediction_resistance)
-{
- size_t ret = 0;
- size_t entropy_available = 0;
- RAND_POOL *pool;
-
- if (drbg->parent != NULL && 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 (drbg->seed_pool != NULL) {
- pool = drbg->seed_pool;
- pool->entropy_requested = entropy;
- } else {
- pool = rand_pool_new(entropy, drbg->secure, min_len, max_len);
- if (pool == NULL)
- return 0;
- }
-
- if (drbg->parent != NULL) {
- 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 data from parent. Include our address as additional input,
- * in order to provide some additional distinction between different
- * DRBG child instances.
- * 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,
- (unsigned char *)&drbg, sizeof(drbg)) != 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 {
- /* Get entropy by polling system entropy sources. */
- entropy_available = rand_pool_acquire_entropy(pool);
- }
-
- if (entropy_available > 0) {
- ret = rand_pool_length(pool);
- *pout = rand_pool_detach(pool);
- }
-
- if (drbg->seed_pool == NULL)
- rand_pool_free(pool);
- return ret;
-}
-
-/*
- * Implements the cleanup_entropy() callback (see RAND_DRBG_set_callbacks())
- *
- */
-void rand_drbg_cleanup_entropy(RAND_DRBG *drbg,
- unsigned char *out, size_t outlen)
-{
- if (drbg->seed_pool == NULL) {
- if (drbg->secure)
- OPENSSL_secure_clear_free(out, outlen);
- else
- OPENSSL_clear_free(out, outlen);
- }
-}
-
-/*
- * 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().
- */
-size_t rand_drbg_get_additional_data(RAND_POOL *pool, unsigned char **pout)
-{
- size_t ret = 0;
-
- if (rand_pool_add_additional_data(pool) == 0)
- goto err;
-
- ret = rand_pool_length(pool);
- *pout = rand_pool_detach(pool);
-
- err:
- return ret;
-}
-
-void rand_drbg_cleanup_additional_data(RAND_POOL *pool, unsigned char *out)
-{
- rand_pool_reattach(pool, out);
-}
-#endif
projects / openssl.git / blobdiff