+ return 0;
+}
+
+void rand_cleanup_int(void)
+{
+ const RAND_METHOD *meth = default_RAND_meth;
+
+ if (meth != NULL && meth->cleanup != NULL)
+ meth->cleanup();
+ rand_pool_cleanup();
+ RAND_set_rand_method(NULL);
+#ifndef OPENSSL_NO_ENGINE
+ CRYPTO_THREAD_lock_free(rand_engine_lock);
+ rand_engine_lock = NULL;
+#endif
+ CRYPTO_THREAD_lock_free(rand_meth_lock);
+ rand_meth_lock = NULL;
+ CRYPTO_THREAD_lock_free(rand_nonce_lock);
+ rand_nonce_lock = NULL;
+}
+
+/*
+ * RAND_close_seed_files() ensures that any seed file decriptors are
+ * closed after use.
+ */
+void RAND_keep_random_devices_open(int keep)
+{
+ 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)
+{
+ 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,
+ DRBG_MINMAX_FACTOR * (RAND_DRBG_STRENGTH / 8));
+ 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, 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);
+ goto err;
+ }
+
+ pool->min_len = min_len;
+ pool->max_len = 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->requested_entropy = entropy;
+
+ return pool;
+
+err:
+ OPENSSL_free(pool);
+ return NULL;
+}
+
+/*
+ * Free |pool|, securely erasing its buffer.
+ */
+void rand_pool_free(RAND_POOL *pool)
+{
+ if (pool == NULL)
+ return;
+
+ 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->requested_entropy)
+ 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->requested_entropy)
+ return pool->requested_entropy - 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;
+}