-/*
- * Re-attach the |pool| buffer. It is only allowed to pass
- * the |buffer| which was previously detached from the same pool.
- */
-void rand_pool_reattach(RAND_POOL *pool, unsigned char *buffer)
-{
- pool->buffer = buffer;
- OPENSSL_cleanse(pool->buffer, pool->len);
- pool->len = 0;
-}
-
-/*
- * 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;
-}
-
-/* Increase the allocation size -- not usable for an attached pool */
-static int rand_pool_grow(RAND_POOL *pool, size_t len)
-{
- if (len > pool->alloc_len - pool->len) {
- unsigned char *p;
- const size_t limit = pool->max_len / 2;
- size_t newlen = pool->alloc_len;
-
- if (pool->attached || len > pool->max_len - pool->len) {
- RANDerr(RAND_F_RAND_POOL_GROW, ERR_R_INTERNAL_ERROR);
- return 0;
- }
-
- do
- newlen = newlen < limit ? newlen * 2 : pool->max_len;
- while (len > newlen - pool->len);
-
- if (pool->secure)
- p = OPENSSL_secure_zalloc(newlen);
- else
- p = OPENSSL_zalloc(newlen);
- if (p == NULL) {
- RANDerr(RAND_F_RAND_POOL_GROW, ERR_R_MALLOC_FAILURE);
- return 0;
- }
- memcpy(p, pool->buffer, pool->len);
- if (pool->secure)
- OPENSSL_secure_clear_free(pool->buffer, pool->alloc_len);
- else
- OPENSSL_clear_free(pool->buffer, pool->alloc_len);
- pool->buffer = p;
- pool->alloc_len = newlen;
- }
- return 1;
-}
-
-/*
- * 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;
-
- /*
- * Make sure the buffer is large enough for the requested amount
- * of data. This guarantees that existing code patterns where
- * rand_pool_add_begin, rand_pool_add_end or rand_pool_add
- * are used to collect entropy data without any error handling
- * whatsoever, continue to be valid.
- * Furthermore if the allocation here fails once, make sure that
- * we don't fall back to a less secure or even blocking random source,
- * as that could happen by the existing code patterns.
- * This is not a concern for additional data, therefore that
- * is not needed if rand_pool_grow fails in other places.
- */
- if (!rand_pool_grow(pool, bytes_needed)) {
- /* persistent error for this pool */
- pool->max_len = pool->len = 0;
- return 0;
- }
-
- 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 (pool->buffer == NULL) {
- RANDerr(RAND_F_RAND_POOL_ADD, ERR_R_INTERNAL_ERROR);
- return 0;
- }
-
- if (len > 0) {
- /*
- * This is to protect us from accidentally passing the buffer
- * returned from rand_pool_add_begin.
- * The check for alloc_len makes sure we do not compare the
- * address of the end of the allocated memory to something
- * different, since that comparison would have an
- * indeterminate result.
- */
- if (pool->alloc_len > pool->len && pool->buffer + pool->len == buffer) {
- RANDerr(RAND_F_RAND_POOL_ADD, ERR_R_INTERNAL_ERROR);
- return 0;
- }
- /*
- * We have that only for cases when a pool is used to collect
- * additional data.
- * For entropy data, as long as the allocation request stays within
- * the limits given by rand_pool_bytes_needed this rand_pool_grow
- * below is guaranteed to succeed, thus no allocation happens.
- */
- if (!rand_pool_grow(pool, len))
- return 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 update 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;
- }
-
- if (pool->buffer == NULL) {
- RANDerr(RAND_F_RAND_POOL_ADD_BEGIN, ERR_R_INTERNAL_ERROR);
- return NULL;
- }
-
- /*
- * As long as the allocation request stays within the limits given
- * by rand_pool_bytes_needed this rand_pool_grow below is guaranteed
- * to succeed, thus no allocation happens.
- * We have that only for cases when a pool is used to collect
- * additional data. Then the buffer might need to grow here,
- * and of course the caller is responsible to check the return
- * value of this function.
- */
- if (!rand_pool_grow(pool, len))
- 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->alloc_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;
-}
-
-#ifndef FIPS_MODULE