/src/openssl30/crypto/rand/rand_pool.c

Source (jump to first uncovered line)
/*
 * 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) {
        ERR_raise(ERR_LIB_RAND, 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->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) {
        ERR_raise(ERR_LIB_RAND, ERR_R_MALLOC_FAILURE);
        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) {
        ERR_raise(ERR_LIB_RAND, 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->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) {
            ERR_raise(ERR_LIB_RAND, 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 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(ERR_LIB_RAND, 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
     * 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: 2025-06-13 06:58

Line	Count	Source (jump to first uncovered line)
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	315	{
25	315	RAND_POOL pool = OPENSSL_zalloc(sizeof(pool));
26	315	size_t min_alloc_size = RAND_POOL_MIN_ALLOCATION(secure);
27
28	315	if (pool == NULL) {
29	0	ERR_raise(ERR_LIB_RAND, ERR_R_MALLOC_FAILURE);
30	0	return NULL;
31	0	}
32
33	315	pool->min_len = min_len;
34	315	pool->max_len = (max_len > RAND_POOL_MAX_LENGTH) ?
35	314	RAND_POOL_MAX_LENGTH : max_len;
36	315	pool->alloc_len = min_len < min_alloc_size ? min_alloc_size : min_len;
37	315	if (pool->alloc_len > pool->max_len)
38	0	pool->alloc_len = pool->max_len;
39
40	315	if (secure)
41	215	pool->buffer = OPENSSL_secure_zalloc(pool->alloc_len);
42	100	else
43	100	pool->buffer = OPENSSL_zalloc(pool->alloc_len);
44
45	315	if (pool->buffer == NULL) {
46	0	ERR_raise(ERR_LIB_RAND, ERR_R_MALLOC_FAILURE);
47	0	goto err;
48	0	}
49
50	315	pool->entropy_requested = entropy_requested;
51	315	pool->secure = secure;
52	315	return pool;
53
54	0	err:
55	0	OPENSSL_free(pool);
56	0	return NULL;
57	315	}
58
59		/*
60		* Attach new random pool to the given buffer
61		*
62		* This function is intended to be used only for feeding random data
63		* provided by RAND_add() and RAND_seed() into the <master> DRBG.
64		*/
65		RAND_POOL ossl_rand_pool_attach(const unsigned char buffer, size_t len,
66		size_t entropy)
67	0	{
68	0	RAND_POOL pool = OPENSSL_zalloc(sizeof(pool));
69
70	0	if (pool == NULL) {
71	0	ERR_raise(ERR_LIB_RAND, ERR_R_MALLOC_FAILURE);
72	0	return NULL;
73	0	}
74
75		/*
76		* The const needs to be cast away, but attached buffers will not be
77		* modified (in contrary to allocated buffers which are zeroed and
78		* freed in the end).
79		*/
80	0	pool->buffer = (unsigned char *) buffer;
81	0	pool->len = len;
82
83	0	pool->attached = 1;
84
85	0	pool->min_len = pool->max_len = pool->alloc_len = pool->len;
86	0	pool->entropy = entropy;
87
88	0	return pool;
89	0	}
90
91		/*
92		* Free \|pool\|, securely erasing its buffer.
93		*/
94		void ossl_rand_pool_free(RAND_POOL *pool)
95	315	{
96	315	if (pool == NULL)
97	0	return;
98
99		/*
100		* Although it would be advisable from a cryptographical viewpoint,
101		* we are not allowed to clear attached buffers, since they are passed
102		* to ossl_rand_pool_attach() as `const unsigned char*`.
103		* (see corresponding comment in ossl_rand_pool_attach()).
104		*/
105	315	if (!pool->attached) {
106	315	if (pool->secure)
107	215	OPENSSL_secure_clear_free(pool->buffer, pool->alloc_len);
108	100	else
109	100	OPENSSL_clear_free(pool->buffer, pool->alloc_len);
110	315	}
111
112	315	OPENSSL_free(pool);
113	315	}
114
115		/*
116		* Return the \|pool\|'s buffer to the caller (readonly).
117		*/
118		const unsigned char ossl_rand_pool_buffer(RAND_POOL pool)
119	1	{
120	1	return pool->buffer;
121	1	}
122
123		/*
124		* Return the \|pool\|'s entropy to the caller.
125		*/
126		size_t ossl_rand_pool_entropy(RAND_POOL *pool)
127	0	{
128	0	return pool->entropy;
129	0	}
130
131		/*
132		* Return the \|pool\|'s buffer length to the caller.
133		*/
134		size_t ossl_rand_pool_length(RAND_POOL *pool)
135	315	{
136	315	return pool->len;
137	315	}
138
139		/*
140		* Detach the \|pool\| buffer and return it to the caller.
141		* It's the responsibility of the caller to free the buffer
142		* using OPENSSL_secure_clear_free() or to re-attach it
143		* again to the pool using ossl_rand_pool_reattach().
144		*/
145		unsigned char ossl_rand_pool_detach(RAND_POOL pool)
146	314	{
147	314	unsigned char *ret = pool->buffer;
148	314	pool->buffer = NULL;
149	314	pool->entropy = 0;
150	314	return ret;
151	314	}
152
153		/*
154		* Re-attach the \|pool\| buffer. It is only allowed to pass
155		* the \|buffer\| which was previously detached from the same pool.
156		*/
157		void ossl_rand_pool_reattach(RAND_POOL pool, unsigned char buffer)
158	0	{
159	0	pool->buffer = buffer;
160	0	OPENSSL_cleanse(pool->buffer, pool->len);
161	0	pool->len = 0;
162	0	}
163
164		/*
165		* If \|entropy_factor\| bits contain 1 bit of entropy, how many bytes does one
166		* need to obtain at least \|bits\| bits of entropy?
167		*/
168		#define ENTROPY_TO_BYTES(bits, entropy_factor) \
169	215	(((bits) * (entropy_factor) + 7) / 8)
170
171
172		/*
173		* Checks whether the \|pool\|'s entropy is available to the caller.
174		* This is the case when entropy count and buffer length are high enough.
175		* Returns
176		*
177		* \|entropy\| if the entropy count and buffer size is large enough
178		* 0 otherwise
179		*/
180		size_t ossl_rand_pool_entropy_available(RAND_POOL *pool)
181	215	{
182	215	if (pool->entropy < pool->entropy_requested)
183	0	return 0;
184
185	215	if (pool->len < pool->min_len)
186	0	return 0;
187
188	215	return pool->entropy;
189	215	}
190
191		/*
192		* Returns the (remaining) amount of entropy needed to fill
193		* the random pool.
194		*/
195
196		size_t ossl_rand_pool_entropy_needed(RAND_POOL *pool)
197	215	{
198	215	if (pool->entropy < pool->entropy_requested)
199	214	return pool->entropy_requested - pool->entropy;
200
201	1	return 0;
202	215	}
203
204		/* Increase the allocation size -- not usable for an attached pool */
205		static int rand_pool_grow(RAND_POOL *pool, size_t len)
206	630	{
207	630	if (len > pool->alloc_len - pool->len) {
208	0	unsigned char *p;
209	0	const size_t limit = pool->max_len / 2;
210	0	size_t newlen = pool->alloc_len;
211
212	0	if (pool->attached \|\| len > pool->max_len - pool->len) {
213	0	ERR_raise(ERR_LIB_RAND, ERR_R_INTERNAL_ERROR);
214	0	return 0;
215	0	}
216
217	0	do
218	0	newlen = newlen < limit ? newlen * 2 : pool->max_len;
219	0	while (len > newlen - pool->len);
220
221	0	if (pool->secure)
222	0	p = OPENSSL_secure_zalloc(newlen);
223	0	else
224	0	p = OPENSSL_zalloc(newlen);
225	0	if (p == NULL) {
226	0	ERR_raise(ERR_LIB_RAND, ERR_R_MALLOC_FAILURE);
227	0	return 0;
228	0	}
229	0	memcpy(p, pool->buffer, pool->len);
230	0	if (pool->secure)
231	0	OPENSSL_secure_clear_free(pool->buffer, pool->alloc_len);
232	0	else
233	0	OPENSSL_clear_free(pool->buffer, pool->alloc_len);
234	0	pool->buffer = p;
235	0	pool->alloc_len = newlen;
236	0	}
237	630	return 1;
238	630	}
239
240		/*
241		* Returns the number of bytes needed to fill the pool, assuming
242		* the input has 1 / \|entropy_factor\| entropy bits per data bit.
243		* In case of an error, 0 is returned.
244		*/
245
246		size_t ossl_rand_pool_bytes_needed(RAND_POOL *pool, unsigned int entropy_factor)
247	215	{
248	215	size_t bytes_needed;
249	215	size_t entropy_needed = ossl_rand_pool_entropy_needed(pool);
250
251	215	if (entropy_factor < 1) {
252	0	ERR_raise(ERR_LIB_RAND, RAND_R_ARGUMENT_OUT_OF_RANGE);
253	0	return 0;
254	0	}
255
256	215	bytes_needed = ENTROPY_TO_BYTES(entropy_needed, entropy_factor);
257
258	215	if (bytes_needed > pool->max_len - pool->len) {
259		/* not enough space left */
260	0	ERR_raise(ERR_LIB_RAND, RAND_R_RANDOM_POOL_OVERFLOW);
261	0	return 0;
262	0	}
263
264	215	if (pool->len < pool->min_len &&
265	215	bytes_needed < pool->min_len - pool->len)
266		/* to meet the min_len requirement */
267	3	bytes_needed = pool->min_len - pool->len;
268
269		/*
270		* Make sure the buffer is large enough for the requested amount
271		* of data. This guarantees that existing code patterns where
272		* ossl_rand_pool_add_begin, ossl_rand_pool_add_end or ossl_rand_pool_add
273		* are used to collect entropy data without any error handling
274		* whatsoever, continue to be valid.
275		* Furthermore if the allocation here fails once, make sure that
276		* we don't fall back to a less secure or even blocking random source,
277		* as that could happen by the existing code patterns.
278		* This is not a concern for additional data, therefore that
279		* is not needed if rand_pool_grow fails in other places.
280		*/
281	215	if (!rand_pool_grow(pool, bytes_needed)) {
282		/* persistent error for this pool */
283	0	pool->max_len = pool->len = 0;
284	0	return 0;
285	0	}
286
287	215	return bytes_needed;
288	215	}
289
290		/* Returns the remaining number of bytes available */
291		size_t ossl_rand_pool_bytes_remaining(RAND_POOL *pool)
292	0	{
293	0	return pool->max_len - pool->len;
294	0	}
295
296		/*
297		* Add random bytes to the random pool.
298		*
299		* It is expected that the \|buffer\| contains \|len\| bytes of
300		* random input which contains at least \|entropy\| bits of
301		* randomness.
302		*
303		* Returns 1 if the added amount is adequate, otherwise 0
304		*/
305		int ossl_rand_pool_add(RAND_POOL *pool,
306		const unsigned char *buffer, size_t len, size_t entropy)
307	200	{
308	200	if (len > pool->max_len - pool->len) {
309	0	ERR_raise(ERR_LIB_RAND, RAND_R_ENTROPY_INPUT_TOO_LONG);
310	0	return 0;
311	0	}
312
313	200	if (pool->buffer == NULL) {
314	0	ERR_raise(ERR_LIB_RAND, ERR_R_INTERNAL_ERROR);
315	0	return 0;
316	0	}
317
318	200	if (len > 0) {
319		/*
320		* This is to protect us from accidentally passing the buffer
321		* returned from ossl_rand_pool_add_begin.
322		* The check for alloc_len makes sure we do not compare the
323		* address of the end of the allocated memory to something
324		* different, since that comparison would have an
325		* indeterminate result.
326		*/
327	200	if (pool->alloc_len > pool->len && pool->buffer + pool->len == buffer) {
328	0	ERR_raise(ERR_LIB_RAND, ERR_R_INTERNAL_ERROR);
329	0	return 0;
330	0	}
331		/*
332		* We have that only for cases when a pool is used to collect
333		* additional data.
334		* For entropy data, as long as the allocation request stays within
335		* the limits given by ossl_rand_pool_bytes_needed this rand_pool_grow
336		* below is guaranteed to succeed, thus no allocation happens.
337		*/
338	200	if (!rand_pool_grow(pool, len))
339	0	return 0;
340	200	memcpy(pool->buffer + pool->len, buffer, len);
341	200	pool->len += len;
342	200	pool->entropy += entropy;
343	200	}
344
345	200	return 1;
346	200	}
347
348		/*
349		* Start to add random bytes to the random pool in-place.
350		*
351		* Reserves the next \|len\| bytes for adding random bytes in-place
352		* and returns a pointer to the buffer.
353		* The caller is allowed to copy up to \|len\| bytes into the buffer.
354		* If \|len\| == 0 this is considered a no-op and a NULL pointer
355		* is returned without producing an error message.
356		*
357		* After updating the buffer, ossl_rand_pool_add_end() needs to be called
358		* to finish the update operation (see next comment).
359		*/
360		unsigned char ossl_rand_pool_add_begin(RAND_POOL pool, size_t len)
361	215	{
362	215	if (len == 0)
363	0	return NULL;
364
365	215	if (len > pool->max_len - pool->len) {
366	0	ERR_raise(ERR_LIB_RAND, RAND_R_RANDOM_POOL_OVERFLOW);
367	0	return NULL;
368	0	}
369
370	215	if (pool->buffer == NULL) {
371	0	ERR_raise(ERR_LIB_RAND, ERR_R_INTERNAL_ERROR);
372	0	return NULL;
373	0	}
374
375		/*
376		* As long as the allocation request stays within the limits given
377		* by ossl_rand_pool_bytes_needed this rand_pool_grow below is guaranteed
378		* to succeed, thus no allocation happens.
379		* We have that only for cases when a pool is used to collect
380		* additional data. Then the buffer might need to grow here,
381		* and of course the caller is responsible to check the return
382		* value of this function.
383		*/
384	215	if (!rand_pool_grow(pool, len))
385	0	return NULL;
386
387	215	return pool->buffer + pool->len;
388	215	}
389
390		/*
391		* Finish to add random bytes to the random pool in-place.
392		*
393		* Finishes an in-place update of the random pool started by
394		* ossl_rand_pool_add_begin() (see previous comment).
395		* It is expected that \|len\| bytes of random input have been added
396		* to the buffer which contain at least \|entropy\| bits of randomness.
397		* It is allowed to add less bytes than originally reserved.
398		*/
399		int ossl_rand_pool_add_end(RAND_POOL *pool, size_t len, size_t entropy)
400	215	{
401	215	if (len > pool->alloc_len - pool->len) {
402	0	ERR_raise(ERR_LIB_RAND, RAND_R_RANDOM_POOL_OVERFLOW);
403	0	return 0;
404	0	}
405
406	215	if (len > 0) {
407	215	pool->len += len;
408	215	pool->entropy += entropy;
409	215	}
410
411	215	return 1;
412	215	}