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