/src/openssl33/crypto/rand/rand_pool.c

Source
/*
 * Copyright 1995-2021 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
 */

#include <stdio.h>
#include <time.h>
#include "internal/cryptlib.h"
#include <openssl/opensslconf.h>
#include "crypto/rand.h"
#include <openssl/engine.h>
#include "internal/thread_once.h"
#include "crypto/rand_pool.h"

/*
 * Allocate memory and initialize a new random pool
 */
RAND_POOL *ossl_rand_pool_new(int entropy_requested, int secure,
    size_t min_len, size_t max_len)
{
    RAND_POOL *pool = OPENSSL_zalloc(sizeof(*pool));
    size_t min_alloc_size = RAND_POOL_MIN_ALLOCATION(secure);

    if (pool == NULL)
        return NULL;

    pool->min_len = min_len;
    pool->max_len = (max_len > RAND_POOL_MAX_LENGTH) ? RAND_POOL_MAX_LENGTH : max_len;
    pool->alloc_len = min_len < min_alloc_size ? min_alloc_size : min_len;
    if (pool->alloc_len > pool->max_len)
        pool->alloc_len = pool->max_len;

    if (secure)
        pool->buffer = OPENSSL_secure_zalloc(pool->alloc_len);
    else
        pool->buffer = OPENSSL_zalloc(pool->alloc_len);

    if (pool->buffer == NULL)
        goto err;

    pool->entropy_requested = entropy_requested;
    pool->secure = secure;
    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 *ossl_rand_pool_attach(const unsigned char *buffer, size_t len,
    size_t entropy)
{
    RAND_POOL *pool = OPENSSL_zalloc(sizeof(*pool));

    if (pool == NULL)
        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->alloc_len = pool->len;
    pool->entropy = entropy;

    return pool;
}

/*
 * Free |pool|, securely erasing its buffer.
 */
void ossl_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 ossl_rand_pool_attach() as `const unsigned char*`.
     * (see corresponding comment in ossl_rand_pool_attach()).
     */
    if (!pool->attached) {
        if (pool->secure)
            OPENSSL_secure_clear_free(pool->buffer, pool->alloc_len);
        else
            OPENSSL_clear_free(pool->buffer, pool->alloc_len);
    }

    OPENSSL_free(pool);
}

/*
 * Return the |pool|'s buffer to the caller (readonly).
 */
const unsigned char *ossl_rand_pool_buffer(RAND_POOL *pool)
{
    return pool->buffer;
}

/*
 * Return the |pool|'s entropy to the caller.
 */
size_t ossl_rand_pool_entropy(RAND_POOL *pool)
{
    return pool->entropy;
}

/*
 * Return the |pool|'s buffer length to the caller.
 */
size_t ossl_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() or to re-attach it
 * again to the pool using ossl_rand_pool_reattach().
 */
unsigned char *ossl_rand_pool_detach(RAND_POOL *pool)
{
    unsigned char *ret = pool->buffer;
    pool->buffer = NULL;
    pool->entropy = 0;
    return ret;
}

/*
 * Re-attach the |pool| buffer. It is only allowed to pass
 * the |buffer| which was previously detached from the same pool.
 */
void ossl_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 ossl_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 ossl_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) {
            ERR_raise(ERR_LIB_RAND, 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)
            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 ossl_rand_pool_bytes_needed(RAND_POOL *pool, unsigned int entropy_factor)
{
    size_t bytes_needed;
    size_t entropy_needed = ossl_rand_pool_entropy_needed(pool);

    if (entropy_factor < 1) {
        ERR_raise(ERR_LIB_RAND, 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 */
        ERR_raise_data(ERR_LIB_RAND, RAND_R_RANDOM_POOL_OVERFLOW,
            "entropy_factor=%u, entropy_needed=%zu, bytes_needed=%zu,"
            "pool->max_len=%zu, pool->len=%zu",
            entropy_factor, entropy_needed, bytes_needed,
            pool->max_len, pool->len);
        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
     * ossl_rand_pool_add_begin, ossl_rand_pool_add_end or ossl_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 ossl_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 ossl_rand_pool_add(RAND_POOL *pool,
    const unsigned char *buffer, size_t len, size_t entropy)
{
    if (len > pool->max_len - pool->len) {
        ERR_raise(ERR_LIB_RAND, RAND_R_ENTROPY_INPUT_TOO_LONG);
        return 0;
    }

    if (pool->buffer == NULL) {
        ERR_raise(ERR_LIB_RAND, ERR_R_INTERNAL_ERROR);
        return 0;
    }

    if (len > 0) {
        /*
         * This is to protect us from accidentally passing the buffer
         * returned from ossl_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) {
            ERR_raise(ERR_LIB_RAND, 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 ossl_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, ossl_rand_pool_add_end() needs to be called
 * to finish the update operation (see next comment).
 */
unsigned char *ossl_rand_pool_add_begin(RAND_POOL *pool, size_t len)
{
    if (len == 0)
        return NULL;

    if (len > pool->max_len - pool->len) {
        ERR_raise(ERR_LIB_RAND, RAND_R_RANDOM_POOL_OVERFLOW);
        return NULL;
    }

    if (pool->buffer == NULL) {
        ERR_raise(ERR_LIB_RAND, ERR_R_INTERNAL_ERROR);
        return NULL;
    }

    /*
     * As long as the allocation request stays within the limits given
     * by ossl_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
 * ossl_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 ossl_rand_pool_add_end(RAND_POOL *pool, size_t len, size_t entropy)
{
    if (len > pool->alloc_len - pool->len) {
        ERR_raise(ERR_LIB_RAND, RAND_R_RANDOM_POOL_OVERFLOW);
        return 0;
    }

    if (len > 0) {
        pool->len += len;
        pool->entropy += entropy;
    }

    return 1;
}

Coverage Report

Created: 2025-12-31 06:58

Line	Count	Source
1		/*
2		* Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
3		*
4		* Licensed under the Apache License 2.0 (the "License"). You may not use
5		* this file except in compliance with the License. You can obtain a copy
6		* in the file LICENSE in the source distribution or at
7		* https://www.openssl.org/source/license.html
8		*/
9
10		#include <stdio.h>
11		#include <time.h>
12		#include "internal/cryptlib.h"
13		#include <openssl/opensslconf.h>
14		#include "crypto/rand.h"
15		#include <openssl/engine.h>
16		#include "internal/thread_once.h"
17		#include "crypto/rand_pool.h"
18
19		/*
20		* Allocate memory and initialize a new random pool
21		*/
22		RAND_POOL *ossl_rand_pool_new(int entropy_requested, int secure,
23		size_t min_len, size_t max_len)
24	1.49k	{
25	1.49k	RAND_POOL pool = OPENSSL_zalloc(sizeof(pool));
26	1.49k	size_t min_alloc_size = RAND_POOL_MIN_ALLOCATION(secure);
27
28	1.49k	if (pool == NULL)
29	0	return NULL;
30
31	1.49k	pool->min_len = min_len;
32	1.49k	pool->max_len = (max_len > RAND_POOL_MAX_LENGTH) ? RAND_POOL_MAX_LENGTH : max_len;
33	1.49k	pool->alloc_len = min_len < min_alloc_size ? min_alloc_size : min_len;
34	1.49k	if (pool->alloc_len > pool->max_len)
35	25	pool->alloc_len = pool->max_len;
36
37	1.49k	if (secure)
38	1.07k	pool->buffer = OPENSSL_secure_zalloc(pool->alloc_len);
39	413	else
40	413	pool->buffer = OPENSSL_zalloc(pool->alloc_len);
41
42	1.49k	if (pool->buffer == NULL)
43	0	goto err;
44
45	1.49k	pool->entropy_requested = entropy_requested;
46	1.49k	pool->secure = secure;
47	1.49k	return pool;
48
49	0	err:
50	0	OPENSSL_free(pool);
51	0	return NULL;
52	1.49k	}
53
54		/*
55		* Attach new random pool to the given buffer
56		*
57		* This function is intended to be used only for feeding random data
58		* provided by RAND_add() and RAND_seed() into the <master> DRBG.
59		*/
60		RAND_POOL ossl_rand_pool_attach(const unsigned char buffer, size_t len,
61		size_t entropy)
62	0	{
63	0	RAND_POOL pool = OPENSSL_zalloc(sizeof(pool));
64
65	0	if (pool == NULL)
66	0	return NULL;
67
68		/*
69		* The const needs to be cast away, but attached buffers will not be
70		* modified (in contrary to allocated buffers which are zeroed and
71		* freed in the end).
72		*/
73	0	pool->buffer = (unsigned char *)buffer;
74	0	pool->len = len;
75
76	0	pool->attached = 1;
77
78	0	pool->min_len = pool->max_len = pool->alloc_len = pool->len;
79	0	pool->entropy = entropy;
80
81	0	return pool;
82	0	}
83
84		/*
85		* Free \|pool\|, securely erasing its buffer.
86		*/
87		void ossl_rand_pool_free(RAND_POOL *pool)
88	1.49k	{
89	1.49k	if (pool == NULL)
90	0	return;
91
92		/*
93		* Although it would be advisable from a cryptographical viewpoint,
94		* we are not allowed to clear attached buffers, since they are passed
95		* to ossl_rand_pool_attach() as `const unsigned char*`.
96		* (see corresponding comment in ossl_rand_pool_attach()).
97		*/
98	1.49k	if (!pool->attached) {
99	1.49k	if (pool->secure)
100	1.07k	OPENSSL_secure_clear_free(pool->buffer, pool->alloc_len);
101	413	else
102	413	OPENSSL_clear_free(pool->buffer, pool->alloc_len);
103	1.49k	}
104
105	1.49k	OPENSSL_free(pool);
106	1.49k	}
107
108		/*
109		* Return the \|pool\|'s buffer to the caller (readonly).
110		*/
111		const unsigned char ossl_rand_pool_buffer(RAND_POOL pool)
112	65	{
113	65	return pool->buffer;
114	65	}
115
116		/*
117		* Return the \|pool\|'s entropy to the caller.
118		*/
119		size_t ossl_rand_pool_entropy(RAND_POOL *pool)
120	0	{
121	0	return pool->entropy;
122	0	}
123
124		/*
125		* Return the \|pool\|'s buffer length to the caller.
126		*/
127		size_t ossl_rand_pool_length(RAND_POOL *pool)
128	1.48k	{
129	1.48k	return pool->len;
130	1.48k	}
131
132		/*
133		* Detach the \|pool\| buffer and return it to the caller.
134		* It's the responsibility of the caller to free the buffer
135		* using OPENSSL_secure_clear_free() or to re-attach it
136		* again to the pool using ossl_rand_pool_reattach().
137		*/
138		unsigned char ossl_rand_pool_detach(RAND_POOL pool)
139	1.42k	{
140	1.42k	unsigned char *ret = pool->buffer;
141	1.42k	pool->buffer = NULL;
142	1.42k	pool->entropy = 0;
143	1.42k	return ret;
144	1.42k	}
145
146		/*
147		* Re-attach the \|pool\| buffer. It is only allowed to pass
148		* the \|buffer\| which was previously detached from the same pool.
149		*/
150		void ossl_rand_pool_reattach(RAND_POOL pool, unsigned char buffer)
151	0	{
152	0	pool->buffer = buffer;
153	0	OPENSSL_cleanse(pool->buffer, pool->len);
154	0	pool->len = 0;
155	0	}
156
157		/*
158		* If \|entropy_factor\| bits contain 1 bit of entropy, how many bytes does one
159		* need to obtain at least \|bits\| bits of entropy?
160		*/
161		#define ENTROPY_TO_BYTES(bits, entropy_factor) \
162	1.07k	(((bits) * (entropy_factor) + 7) / 8)
163
164		/*
165		* Checks whether the \|pool\|'s entropy is available to the caller.
166		* This is the case when entropy count and buffer length are high enough.
167		* Returns
168		*
169		* \|entropy\| if the entropy count and buffer size is large enough
170		* 0 otherwise
171		*/
172		size_t ossl_rand_pool_entropy_available(RAND_POOL *pool)
173	1.07k	{
174	1.07k	if (pool->entropy < pool->entropy_requested)
175	0	return 0;
176
177	1.07k	if (pool->len < pool->min_len)
178	0	return 0;
179
180	1.07k	return pool->entropy;
181	1.07k	}
182
183		/*
184		* Returns the (remaining) amount of entropy needed to fill
185		* the random pool.
186		*/
187
188		size_t ossl_rand_pool_entropy_needed(RAND_POOL *pool)
189	1.07k	{
190	1.07k	if (pool->entropy < pool->entropy_requested)
191	1.01k	return pool->entropy_requested - pool->entropy;
192
193	66	return 0;
194	1.07k	}
195
196		/* Increase the allocation size -- not usable for an attached pool */
197		static int rand_pool_grow(RAND_POOL *pool, size_t len)
198	2.97k	{
199	2.97k	if (len > pool->alloc_len - pool->len) {
200	0	unsigned char *p;
201	0	const size_t limit = pool->max_len / 2;
202	0	size_t newlen = pool->alloc_len;
203
204	0	if (pool->attached \|\| len > pool->max_len - pool->len) {
205	0	ERR_raise(ERR_LIB_RAND, ERR_R_INTERNAL_ERROR);
206	0	return 0;
207	0	}
208
209	0	do
210	0	newlen = newlen < limit ? newlen * 2 : pool->max_len;
211	0	while (len > newlen - pool->len);
212
213	0	if (pool->secure)
214	0	p = OPENSSL_secure_zalloc(newlen);
215	0	else
216	0	p = OPENSSL_zalloc(newlen);
217	0	if (p == NULL)
218	0	return 0;
219	0	memcpy(p, pool->buffer, pool->len);
220	0	if (pool->secure)
221	0	OPENSSL_secure_clear_free(pool->buffer, pool->alloc_len);
222	0	else
223	0	OPENSSL_clear_free(pool->buffer, pool->alloc_len);
224	0	pool->buffer = p;
225	0	pool->alloc_len = newlen;
226	0	}
227	2.97k	return 1;
228	2.97k	}
229
230		/*
231		* Returns the number of bytes needed to fill the pool, assuming
232		* the input has 1 / \|entropy_factor\| entropy bits per data bit.
233		* In case of an error, 0 is returned.
234		*/
235
236		size_t ossl_rand_pool_bytes_needed(RAND_POOL *pool, unsigned int entropy_factor)
237	1.07k	{
238	1.07k	size_t bytes_needed;
239	1.07k	size_t entropy_needed = ossl_rand_pool_entropy_needed(pool);
240
241	1.07k	if (entropy_factor < 1) {
242	0	ERR_raise(ERR_LIB_RAND, RAND_R_ARGUMENT_OUT_OF_RANGE);
243	0	return 0;
244	0	}
245
246	1.07k	bytes_needed = ENTROPY_TO_BYTES(entropy_needed, entropy_factor);
247
248	1.07k	if (bytes_needed > pool->max_len - pool->len) {
249		/* not enough space left */
250	0	ERR_raise_data(ERR_LIB_RAND, RAND_R_RANDOM_POOL_OVERFLOW,
251	0	"entropy_factor=%u, entropy_needed=%zu, bytes_needed=%zu,"
252	0	"pool->max_len=%zu, pool->len=%zu",
253	0	entropy_factor, entropy_needed, bytes_needed,
254	0	pool->max_len, pool->len);
255	0	return 0;
256	0	}
257
258	1.07k	if (pool->len < pool->min_len && bytes_needed < pool->min_len - pool->len)
259		/* to meet the min_len requirement */
260	68	bytes_needed = pool->min_len - pool->len;
261
262		/*
263		* Make sure the buffer is large enough for the requested amount
264		* of data. This guarantees that existing code patterns where
265		* ossl_rand_pool_add_begin, ossl_rand_pool_add_end or ossl_rand_pool_add
266		* are used to collect entropy data without any error handling
267		* whatsoever, continue to be valid.
268		* Furthermore if the allocation here fails once, make sure that
269		* we don't fall back to a less secure or even blocking random source,
270		* as that could happen by the existing code patterns.
271		* This is not a concern for additional data, therefore that
272		* is not needed if rand_pool_grow fails in other places.
273		*/
274	1.07k	if (!rand_pool_grow(pool, bytes_needed)) {
275		/* persistent error for this pool */
276	0	pool->max_len = pool->len = 0;
277	0	return 0;
278	0	}
279
280	1.07k	return bytes_needed;
281	1.07k	}
282
283		/* Returns the remaining number of bytes available */
284		size_t ossl_rand_pool_bytes_remaining(RAND_POOL *pool)
285	0	{
286	0	return pool->max_len - pool->len;
287	0	}
288
289		/*
290		* Add random bytes to the random pool.
291		*
292		* It is expected that the \|buffer\| contains \|len\| bytes of
293		* random input which contains at least \|entropy\| bits of
294		* randomness.
295		*
296		* Returns 1 if the added amount is adequate, otherwise 0
297		*/
298		int ossl_rand_pool_add(RAND_POOL *pool,
299		const unsigned char *buffer, size_t len, size_t entropy)
300	826	{
301	826	if (len > pool->max_len - pool->len) {
302	0	ERR_raise(ERR_LIB_RAND, RAND_R_ENTROPY_INPUT_TOO_LONG);
303	0	return 0;
304	0	}
305
306	826	if (pool->buffer == NULL) {
307	0	ERR_raise(ERR_LIB_RAND, ERR_R_INTERNAL_ERROR);
308	0	return 0;
309	0	}
310
311	826	if (len > 0) {
312		/*
313		* This is to protect us from accidentally passing the buffer
314		* returned from ossl_rand_pool_add_begin.
315		* The check for alloc_len makes sure we do not compare the
316		* address of the end of the allocated memory to something
317		* different, since that comparison would have an
318		* indeterminate result.
319		*/
320	826	if (pool->alloc_len > pool->len && pool->buffer + pool->len == buffer) {
321	0	ERR_raise(ERR_LIB_RAND, ERR_R_INTERNAL_ERROR);
322	0	return 0;
323	0	}
324		/*
325		* We have that only for cases when a pool is used to collect
326		* additional data.
327		* For entropy data, as long as the allocation request stays within
328		* the limits given by ossl_rand_pool_bytes_needed this rand_pool_grow
329		* below is guaranteed to succeed, thus no allocation happens.
330		*/
331	826	if (!rand_pool_grow(pool, len))
332	0	return 0;
333	826	memcpy(pool->buffer + pool->len, buffer, len);
334	826	pool->len += len;
335	826	pool->entropy += entropy;
336	826	}
337
338	826	return 1;
339	826	}
340
341		/*
342		* Start to add random bytes to the random pool in-place.
343		*
344		* Reserves the next \|len\| bytes for adding random bytes in-place
345		* and returns a pointer to the buffer.
346		* The caller is allowed to copy up to \|len\| bytes into the buffer.
347		* If \|len\| == 0 this is considered a no-op and a NULL pointer
348		* is returned without producing an error message.
349		*
350		* After updating the buffer, ossl_rand_pool_add_end() needs to be called
351		* to finish the update operation (see next comment).
352		*/
353		unsigned char ossl_rand_pool_add_begin(RAND_POOL pool, size_t len)
354	1.07k	{
355	1.07k	if (len == 0)
356	0	return NULL;
357
358	1.07k	if (len > pool->max_len - pool->len) {
359	0	ERR_raise(ERR_LIB_RAND, RAND_R_RANDOM_POOL_OVERFLOW);
360	0	return NULL;
361	0	}
362
363	1.07k	if (pool->buffer == NULL) {
364	0	ERR_raise(ERR_LIB_RAND, ERR_R_INTERNAL_ERROR);
365	0	return NULL;
366	0	}
367
368		/*
369		* As long as the allocation request stays within the limits given
370		* by ossl_rand_pool_bytes_needed this rand_pool_grow below is guaranteed
371		* to succeed, thus no allocation happens.
372		* We have that only for cases when a pool is used to collect
373		* additional data. Then the buffer might need to grow here,
374		* and of course the caller is responsible to check the return
375		* value of this function.
376		*/
377	1.07k	if (!rand_pool_grow(pool, len))
378	0	return NULL;
379
380	1.07k	return pool->buffer + pool->len;
381	1.07k	}
382
383		/*
384		* Finish to add random bytes to the random pool in-place.
385		*
386		* Finishes an in-place update of the random pool started by
387		* ossl_rand_pool_add_begin() (see previous comment).
388		* It is expected that \|len\| bytes of random input have been added
389		* to the buffer which contain at least \|entropy\| bits of randomness.
390		* It is allowed to add less bytes than originally reserved.
391		*/
392		int ossl_rand_pool_add_end(RAND_POOL *pool, size_t len, size_t entropy)
393	1.07k	{
394	1.07k	if (len > pool->alloc_len - pool->len) {
395	0	ERR_raise(ERR_LIB_RAND, RAND_R_RANDOM_POOL_OVERFLOW);
396	0	return 0;
397	0	}
398
399	1.07k	if (len > 0) {
400	1.07k	pool->len += len;
401	1.07k	pool->entropy += entropy;
402	1.07k	}
403
404	1.07k	return 1;
405	1.07k	}