1 /* crypto/rand/randfile.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
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 (tjh@cryptsoft.com).
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 (eay@cryptsoft.com)"
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 (tjh@cryptsoft.com)"
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 /* We need to define this to get macros like S_IFBLK and S_IFCHR */
60 #if !defined(OPENSSL_SYS_VXWORKS)
61 #define _XOPEN_SOURCE 500
62 #endif
63
64 #include <errno.h>
65 #include <stdio.h>
66 #include <stdlib.h>
67 #include <string.h>
68
69 #include "e_os.h"
70 #include <openssl/crypto.h>
71 #include <openssl/rand.h>
72 #include <openssl/buffer.h>
73
74 #ifdef OPENSSL_SYS_VMS
75 #include <unixio.h>
76 #endif
77 #ifndef NO_SYS_TYPES_H
78 # include <sys/types.h>
79 #endif
80 #ifndef OPENSSL_NO_POSIX_IO
81 # include <sys/stat.h>
82 # include <fcntl.h>
83 #endif
84
85 #ifdef _WIN32
86 #define stat _stat
87 #define chmod _chmod
88 #define open _open
89 #define fdopen _fdopen
90 #endif
91
92 #undef BUFSIZE
93 #define BUFSIZE 1024
94 #define RAND_DATA 1024
95
96 #ifdef OPENSSL_SYS_VMS
97 /* This declaration is a nasty hack to get around vms' extension to fopen
98 * for passing in sharing options being disabled by our /STANDARD=ANSI89 */
99 static FILE *(*const vms_fopen)(const char *, const char *, ...) =
100 (FILE *(*)(const char *, const char *, ...))fopen;
101 #define VMS_OPEN_ATTRS "shr=get,put,upd,del","ctx=bin,stm","rfm=stm","rat=none","mrs=0"
102 #endif
103
104 /* #define RFILE ".rnd" - defined in ../../e_os.h */
105
106 /* Note that these functions are intended for seed files only.
107 * Entropy devices and EGD sockets are handled in rand_unix.c */
108
109 int RAND_load_file(const char *file, long bytes)
110 {
111 /* If bytes >= 0, read up to 'bytes' bytes.
112 * if bytes == -1, read complete file. */
113
114 MS_STATIC unsigned char buf[BUFSIZE];
115 #ifndef OPENSSL_NO_POSIX_IO
116 struct stat sb;
117 #endif
118 int i,ret=0,n;
119 FILE *in;
120
121 if (file == NULL) return(0);
122
123 #ifndef OPENSSL_NO_POSIX_IO
124 #ifdef PURIFY
125 /* struct stat can have padding and unused fields that may not be
126 * initialized in the call to stat(). We need to clear the entire
127 * structure before calling RAND_add() to avoid complaints from
128 * applications such as Valgrind.
129 */
130 memset(&sb, 0, sizeof(sb));
131 #endif
132 if (stat(file,&sb) < 0) return(0);
133 RAND_add(&sb,sizeof(sb),0.0);
134 #endif
135 if (bytes == 0) return(ret);
136
137 #ifdef OPENSSL_SYS_VMS
138 in=vms_fopen(file,"rb",VMS_OPEN_ATTRS);
139 #else
140 in=fopen(file,"rb");
141 #endif
142 if (in == NULL) goto err;
143 #if defined(S_IFBLK) && defined(S_IFCHR) && !defined(OPENSSL_NO_POSIX_IO)
144 if (sb.st_mode & (S_IFBLK | S_IFCHR)) {
145 /* this file is a device. we don't want read an infinite number
146 * of bytes from a random device, nor do we want to use buffered
147 * I/O because we will waste system entropy.
148 */
149 bytes = (bytes == -1) ? 2048 : bytes; /* ok, is 2048 enough? */
150 #ifndef OPENSSL_NO_SETVBUF_IONBF
151 setvbuf(in, NULL, _IONBF, 0); /* don't do buffered reads */
152 #endif /* ndef OPENSSL_NO_SETVBUF_IONBF */
153 }
154 #endif
155 for (;;)
156 {
157 if (bytes > 0)
158 n = (bytes < BUFSIZE)?(int)bytes:BUFSIZE;
159 else
160 n = BUFSIZE;
161 i=fread(buf,1,n,in);
162 if (i <= 0) break;
163 #ifdef PURIFY
164 RAND_add(buf,i,(double)i);
165 #else
166 /* even if n != i, use the full array */
167 RAND_add(buf,n,(double)i);
168 #endif
169 ret+=i;
170 if (bytes > 0)
171 {
172 bytes-=n;
173 if (bytes <= 0) break;
174 }
175 }
176 fclose(in);
177 OPENSSL_cleanse(buf,BUFSIZE);
178 err:
179 return(ret);
180 }
181
182 int RAND_write_file(const char *file)
183 {
184 unsigned char buf[BUFSIZE];
185 int i,ret=0,rand_err=0;
186 FILE *out = NULL;
187 int n;
188 #ifndef OPENSSL_NO_POSIX_IO
189 struct stat sb;
190
191 i=stat(file,&sb);
192 if (i != -1) {
193 #if defined(S_ISBLK) && defined(S_ISCHR)
194 if (S_ISBLK(sb.st_mode) || S_ISCHR(sb.st_mode)) {
195 /* this file is a device. we don't write back to it.
196 * we "succeed" on the assumption this is some sort
197 * of random device. Otherwise attempting to write to
198 * and chmod the device causes problems.
199 */
200 return(1);
201 }
202 #endif
203 }
204 #endif
205
206 #if defined(O_CREAT) && !defined(OPENSSL_NO_POSIX_IO) && !defined(OPENSSL_SYS_VMS)
207 {
208 #ifndef O_BINARY
209 #define O_BINARY 0
210 #endif
211 /* chmod(..., 0600) is too late to protect the file,
212 * permissions should be restrictive from the start */
213 int fd = open(file, O_WRONLY|O_CREAT|O_BINARY, 0600);
214 if (fd != -1)
215 out = fdopen(fd, "wb");
216 }
217 #endif
218
219 #ifdef OPENSSL_SYS_VMS
220 /* VMS NOTE: Prior versions of this routine created a _new_
221 * version of the rand file for each call into this routine, then
222 * deleted all existing versions named ;-1, and finally renamed
223 * the current version as ';1'. Under concurrent usage, this
224 * resulted in an RMS race condition in rename() which could
225 * orphan files (see vms message help for RMS$_REENT). With the
226 * fopen() calls below, openssl/VMS now shares the top-level
227 * version of the rand file. Note that there may still be
228 * conditions where the top-level rand file is locked. If so, this
229 * code will then create a new version of the rand file. Without
230 * the delete and rename code, this can result in ascending file
231 * versions that stop at version 32767, and this routine will then
232 * return an error. The remedy for this is to recode the calling
233 * application to avoid concurrent use of the rand file, or
234 * synchronize usage at the application level. Also consider
235 * whether or not you NEED a persistent rand file in a concurrent
236 * use situation.
237 */
238
239 out = vms_fopen(file,"rb+",VMS_OPEN_ATTRS);
240 if (out == NULL)
241 out = vms_fopen(file,"wb",VMS_OPEN_ATTRS);
242 #else
243 if (out == NULL)
244 out = fopen(file,"wb");
245 #endif
246 if (out == NULL) goto err;
247
248 #ifndef NO_CHMOD
249 chmod(file,0600);
250 #endif
251 n=RAND_DATA;
252 for (;;)
253 {
254 i=(n > BUFSIZE)?BUFSIZE:n;
255 n-=BUFSIZE;
256 if (RAND_bytes(buf,i) <= 0)
257 rand_err=1;
258 i=fwrite(buf,1,i,out);
259 if (i <= 0)
260 {
261 ret=0;
262 break;
263 }
264 ret+=i;
265 if (n <= 0) break;
266 }
267
268 fclose(out);
269 OPENSSL_cleanse(buf,BUFSIZE);
270 err:
271 return (rand_err ? -1 : ret);
272 }
273
274 const char *RAND_file_name(char *buf, size_t size)
275 {
276 char *s=NULL;
277 #ifdef __OpenBSD__
278 struct stat sb;
279 #endif
280
281 if (OPENSSL_issetugid() == 0)
282 s=getenv("RANDFILE");
283 if (s != NULL && *s && strlen(s) + 1 < size)
284 {
285 if (BUF_strlcpy(buf,s,size) >= size)
286 return NULL;
287 }
288 else
289 {
290 if (OPENSSL_issetugid() == 0)
291 s=getenv("HOME");
292 #ifdef DEFAULT_HOME
293 if (s == NULL)
294 {
295 s = DEFAULT_HOME;
296 }
297 #endif
298 if (s && *s && strlen(s)+strlen(RFILE)+2 < size)
299 {
300 BUF_strlcpy(buf,s,size);
301 #ifndef OPENSSL_SYS_VMS
302 BUF_strlcat(buf,"/",size);
303 #endif
304 BUF_strlcat(buf,RFILE,size);
305 }
306 else
307 buf[0] = '\0'; /* no file name */
308 }
309
310 #ifdef __OpenBSD__
311 /* given that all random loads just fail if the file can't be
312 * seen on a stat, we stat the file we're returning, if it
313 * fails, use /dev/arandom instead. this allows the user to
314 * use their own source for good random data, but defaults
315 * to something hopefully decent if that isn't available.
316 */
317
318 if (!buf[0])
319 if (BUF_strlcpy(buf,"/dev/arandom",size) >= size) {
320 return(NULL);
321 }
322 if (stat(buf,&sb) == -1)
323 if (BUF_strlcpy(buf,"/dev/arandom",size) >= size) {
324 return(NULL);
325 }
326
327 #endif
328 return(buf);
329 }