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rand_lib.c
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1 /* crypto/rand/rand_lib.c */
2 /* Copyright (C) 1995-1998 Eric Young ([email protected])
3  * All rights reserved.
4  *
5  * This package is an SSL implementation written
6  * by Eric Young ([email protected]).
7  * The implementation was written so as to conform with Netscapes SSL.
8  *
9  * This library is free for commercial and non-commercial use as long as
10  * the following conditions are aheared to. The following conditions
11  * apply to all code found in this distribution, be it the RC4, RSA,
12  * lhash, DES, etc., code; not just the SSL code. The SSL documentation
13  * included with this distribution is covered by the same copyright terms
14  * except that the holder is Tim Hudson ([email protected]).
15  *
16  * Copyright remains Eric Young's, and as such any Copyright notices in
17  * the code are not to be removed.
18  * If this package is used in a product, Eric Young should be given attribution
19  * as the author of the parts of the library used.
20  * This can be in the form of a textual message at program startup or
21  * in documentation (online or textual) provided with the package.
22  *
23  * Redistribution and use in source and binary forms, with or without
24  * modification, are permitted provided that the following conditions
25  * are met:
26  * 1. Redistributions of source code must retain the copyright
27  * notice, this list of conditions and the following disclaimer.
28  * 2. Redistributions in binary form must reproduce the above copyright
29  * notice, this list of conditions and the following disclaimer in the
30  * documentation and/or other materials provided with the distribution.
31  * 3. All advertising materials mentioning features or use of this software
32  * must display the following acknowledgement:
33  * "This product includes cryptographic software written by
34  * Eric Young ([email protected])"
35  * The word 'cryptographic' can be left out if the rouines from the library
36  * being used are not cryptographic related :-).
37  * 4. If you include any Windows specific code (or a derivative thereof) from
38  * the apps directory (application code) you must include an acknowledgement:
39  * "This product includes software written by Tim Hudson ([email protected])"
40  *
41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51  * SUCH DAMAGE.
52  *
53  * The licence and distribution terms for any publically available version or
54  * derivative of this code cannot be changed. i.e. this code cannot simply be
55  * copied and put under another distribution licence
56  * [including the GNU Public Licence.]
57  */
58 
59 #include <stdio.h>
60 #include <time.h>
61 #include "cryptlib.h"
62 #include <openssl/rand.h>
63 
64 #ifndef OPENSSL_NO_ENGINE
65 #include <openssl/engine.h>
66 #endif
67 
68 #ifdef OPENSSL_FIPS
69 #include <openssl/fips.h>
70 #include <openssl/fips_rand.h>
71 #endif
72 
73 #ifndef OPENSSL_NO_ENGINE
74 /* non-NULL if default_RAND_meth is ENGINE-provided */
75 static ENGINE *funct_ref =NULL;
76 #endif
77 static const RAND_METHOD *default_RAND_meth = NULL;
78 
80  {
81 #ifndef OPENSSL_NO_ENGINE
82  if(funct_ref)
83  {
84  ENGINE_finish(funct_ref);
85  funct_ref = NULL;
86  }
87 #endif
88  default_RAND_meth = meth;
89  return 1;
90  }
91 
93  {
94  if (!default_RAND_meth)
95  {
96 #ifndef OPENSSL_NO_ENGINE
98  if(e)
99  {
100  default_RAND_meth = ENGINE_get_RAND(e);
101  if(!default_RAND_meth)
102  {
103  ENGINE_finish(e);
104  e = NULL;
105  }
106  }
107  if(e)
108  funct_ref = e;
109  else
110 #endif
111  default_RAND_meth = RAND_SSLeay();
112  }
113  return default_RAND_meth;
114  }
115 
116 #ifndef OPENSSL_NO_ENGINE
118  {
119  const RAND_METHOD *tmp_meth = NULL;
120  if(engine)
121  {
122  if(!ENGINE_init(engine))
123  return 0;
124  tmp_meth = ENGINE_get_RAND(engine);
125  if(!tmp_meth)
126  {
127  ENGINE_finish(engine);
128  return 0;
129  }
130  }
131  /* This function releases any prior ENGINE so call it first */
132  RAND_set_rand_method(tmp_meth);
133  funct_ref = engine;
134  return 1;
135  }
136 #endif
137 
138 void RAND_cleanup(void)
139  {
140  const RAND_METHOD *meth = RAND_get_rand_method();
141  if (meth && meth->cleanup)
142  meth->cleanup();
143  RAND_set_rand_method(NULL);
144  }
145 
146 void RAND_seed(const void *buf, int num)
147  {
148  const RAND_METHOD *meth = RAND_get_rand_method();
149  if (meth && meth->seed)
150  meth->seed(buf,num);
151  }
152 
153 void RAND_add(const void *buf, int num, double entropy)
154  {
155  const RAND_METHOD *meth = RAND_get_rand_method();
156  if (meth && meth->add)
157  meth->add(buf,num,entropy);
158  }
159 
160 int RAND_bytes(unsigned char *buf, int num)
161  {
162  const RAND_METHOD *meth = RAND_get_rand_method();
163  if (meth && meth->bytes)
164  return meth->bytes(buf,num);
165  return(-1);
166  }
167 
168 int RAND_pseudo_bytes(unsigned char *buf, int num)
169  {
170  const RAND_METHOD *meth = RAND_get_rand_method();
171  if (meth && meth->pseudorand)
172  return meth->pseudorand(buf,num);
173  return(-1);
174  }
175 
176 int RAND_status(void)
177  {
178  const RAND_METHOD *meth = RAND_get_rand_method();
179  if (meth && meth->status)
180  return meth->status();
181  return 0;
182  }
183 
184 #ifdef OPENSSL_FIPS
185 
186 /* FIPS DRBG initialisation code. This sets up the DRBG for use by the
187  * rest of OpenSSL.
188  */
189 
190 /* Entropy gatherer: use standard OpenSSL PRNG to seed (this will gather
191  * entropy internally through RAND_poll().
192  */
193 
194 static size_t drbg_get_entropy(DRBG_CTX *ctx, unsigned char **pout,
195  int entropy, size_t min_len, size_t max_len)
196  {
197  /* Round up request to multiple of block size */
198  min_len = ((min_len + 19) / 20) * 20;
199  *pout = OPENSSL_malloc(min_len);
200  if (!*pout)
201  return 0;
202  if (RAND_SSLeay()->bytes(*pout, min_len) <= 0)
203  {
204  OPENSSL_free(*pout);
205  *pout = NULL;
206  return 0;
207  }
208  return min_len;
209  }
210 
211 static void drbg_free_entropy(DRBG_CTX *ctx, unsigned char *out, size_t olen)
212  {
213  OPENSSL_cleanse(out, olen);
214  OPENSSL_free(out);
215  }
216 
217 /* Set "additional input" when generating random data. This uses the
218  * current PID, a time value and a counter.
219  */
220 
221 static size_t drbg_get_adin(DRBG_CTX *ctx, unsigned char **pout)
222  {
223  /* Use of static variables is OK as this happens under a lock */
224  static unsigned char buf[16];
225  static unsigned long counter;
226  FIPS_get_timevec(buf, &counter);
227  *pout = buf;
228  return sizeof(buf);
229  }
230 
231 /* RAND_add() and RAND_seed() pass through to OpenSSL PRNG so it is
232  * correctly seeded by RAND_poll().
233  */
234 
235 static int drbg_rand_add(DRBG_CTX *ctx, const void *in, int inlen,
236  double entropy)
237  {
238  RAND_SSLeay()->add(in, inlen, entropy);
239  return 1;
240  }
241 
242 static int drbg_rand_seed(DRBG_CTX *ctx, const void *in, int inlen)
243  {
244  RAND_SSLeay()->seed(in, inlen);
245  return 1;
246  }
247 
248 #ifndef OPENSSL_DRBG_DEFAULT_TYPE
249 #define OPENSSL_DRBG_DEFAULT_TYPE NID_aes_256_ctr
250 #endif
251 #ifndef OPENSSL_DRBG_DEFAULT_FLAGS
252 #define OPENSSL_DRBG_DEFAULT_FLAGS DRBG_FLAG_CTR_USE_DF
253 #endif
254 
255 static int fips_drbg_type = OPENSSL_DRBG_DEFAULT_TYPE;
256 static int fips_drbg_flags = OPENSSL_DRBG_DEFAULT_FLAGS;
257 
258 void RAND_set_fips_drbg_type(int type, int flags)
259  {
260  fips_drbg_type = type;
261  fips_drbg_flags = flags;
262  }
263 
264 int RAND_init_fips(void)
265  {
266  DRBG_CTX *dctx;
267  size_t plen;
268  unsigned char pers[32], *p;
269  dctx = FIPS_get_default_drbg();
270  if (FIPS_drbg_init(dctx, fips_drbg_type, fips_drbg_flags) <= 0)
271  {
273  return 0;
274  }
275 
276  FIPS_drbg_set_callbacks(dctx,
277  drbg_get_entropy, drbg_free_entropy, 20,
278  drbg_get_entropy, drbg_free_entropy);
279  FIPS_drbg_set_rand_callbacks(dctx, drbg_get_adin, 0,
280  drbg_rand_seed, drbg_rand_add);
281  /* Personalisation string: a string followed by date time vector */
282  strcpy((char *)pers, "OpenSSL DRBG2.0");
283  plen = drbg_get_adin(dctx, &p);
284  memcpy(pers + 16, p, plen);
285 
286  if (FIPS_drbg_instantiate(dctx, pers, sizeof(pers)) <= 0)
287  {
289  return 0;
290  }
291  FIPS_rand_set_method(FIPS_drbg_method());
292  return 1;
293  }
294 
295 #endif