1 /* crypto/rand/randfile.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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.
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).
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.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
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)"
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
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.]
59 /* We need to define this to get macros like S_IFBLK and S_IFCHR */
60 #define _XOPEN_SOURCE 500
68 #include <openssl/crypto.h>
69 #include <openssl/rand.h>
70 #include <openssl/buffer.h>
72 #ifdef OPENSSL_SYS_VMS
75 #ifndef NO_SYS_TYPES_H
76 # include <sys/types.h>
81 # include <sys/stat.h>
88 # define fdopen _fdopen
93 #define RAND_DATA 1024
95 #ifdef OPENSSL_SYS_VMS
97 * This declaration is a nasty hack to get around vms' extension to fopen for
98 * passing in sharing options being disabled by our /STANDARD=ANSI89
100 static FILE *(*const vms_fopen)(const char *, const char *, ...) =
101 (FILE *(*)(const char *, const char *, ...))fopen;
102 # define VMS_OPEN_ATTRS "shr=get,put,upd,del","ctx=bin,stm","rfm=stm","rat=none","mrs=0"
105 /* #define RFILE ".rnd" - defined in ../../e_os.h */
108 * Note that these functions are intended for seed files only. Entropy
109 * devices and EGD sockets are handled in rand_unix.c
112 int RAND_load_file(const char *file, long bytes)
115 * If bytes >= 0, read up to 'bytes' bytes.
116 * if bytes == -1, read complete file.
119 MS_STATIC unsigned char buf[BUFSIZE];
129 * struct stat can have padding and unused fields that may not be
130 * initialized in the call to stat(). We need to clear the entire
131 * structure before calling RAND_add() to avoid complaints from
132 * applications such as Valgrind.
134 memset(&sb, 0, sizeof(sb));
137 if (stat(file, &sb) < 0)
139 RAND_add(&sb, sizeof(sb), 0.0);
143 #ifdef OPENSSL_SYS_VMS
144 in = vms_fopen(file, "rb", VMS_OPEN_ATTRS);
146 in = fopen(file, "rb");
150 #if defined(S_ISBLK) && defined(S_ISCHR)
151 if (S_ISBLK(sb.st_mode) || S_ISCHR(sb.st_mode)) {
153 * this file is a device. we don't want read an infinite number of
154 * bytes from a random device, nor do we want to use buffered I/O
155 * because we will waste system entropy.
157 bytes = (bytes == -1) ? 2048 : bytes; /* ok, is 2048 enough? */
158 setvbuf(in, NULL, _IONBF, 0); /* don't do buffered reads */
163 n = (bytes < BUFSIZE) ? (int)bytes : BUFSIZE;
166 i = fread(buf, 1, n, in);
170 RAND_add(buf, i, (double)i);
172 /* even if n != i, use the full array */
173 RAND_add(buf, n, (double)i);
183 OPENSSL_cleanse(buf, BUFSIZE);
188 int RAND_write_file(const char *file)
190 unsigned char buf[BUFSIZE];
191 int i, ret = 0, rand_err = 0;
198 #if defined(S_ISBLK) && defined(S_ISCHR)
199 if (S_ISBLK(sb.st_mode) || S_ISCHR(sb.st_mode)) {
201 * this file is a device. we don't write back to it. we
202 * "succeed" on the assumption this is some sort of random
203 * device. Otherwise attempting to write to and chmod the device
210 #if defined(O_CREAT) && !defined(OPENSSL_SYS_WIN32) && !defined(OPENSSL_SYS_VMS)
212 /* For some reason Win32 can't write to files created this way */
215 * chmod(..., 0600) is too late to protect the file, permissions
216 * should be restrictive from the start
218 int fd = open(file, O_CREAT, 0600);
220 out = fdopen(fd, "wb");
224 #ifdef OPENSSL_SYS_VMS
226 * VMS NOTE: Prior versions of this routine created a _new_ version of
227 * the rand file for each call into this routine, then deleted all
228 * existing versions named ;-1, and finally renamed the current version
229 * as ';1'. Under concurrent usage, this resulted in an RMS race
230 * condition in rename() which could orphan files (see vms message help
231 * for RMS$_REENT). With the fopen() calls below, openssl/VMS now shares
232 * the top-level version of the rand file. Note that there may still be
233 * conditions where the top-level rand file is locked. If so, this code
234 * will then create a new version of the rand file. Without the delete
235 * and rename code, this can result in ascending file versions that stop
236 * at version 32767, and this routine will then return an error. The
237 * remedy for this is to recode the calling application to avoid
238 * concurrent use of the rand file, or synchronize usage at the
239 * application level. Also consider whether or not you NEED a persistent
240 * rand file in a concurrent use situation.
243 out = vms_fopen(file, "rb+", VMS_OPEN_ATTRS);
245 out = vms_fopen(file, "wb", VMS_OPEN_ATTRS);
248 out = fopen(file, "wb");
258 i = (n > BUFSIZE) ? BUFSIZE : n;
260 if (RAND_bytes(buf, i) <= 0)
262 i = fwrite(buf, 1, i, out);
273 OPENSSL_cleanse(buf, BUFSIZE);
275 return (rand_err ? -1 : ret);
278 const char *RAND_file_name(char *buf, size_t size)
286 if (OPENSSL_issetugid() == 0)
287 s = getenv("RANDFILE");
288 if (s != NULL && *s && strlen(s) + 1 < size) {
289 if (BUF_strlcpy(buf, s, size) >= size)
292 if (OPENSSL_issetugid() == 0)
299 if (s && *s && strlen(s) + strlen(RFILE) + 2 < size) {
300 BUF_strlcpy(buf, s, size);
301 #ifndef OPENSSL_SYS_VMS
302 BUF_strlcat(buf, "/", size);
304 BUF_strlcat(buf, RFILE, size);
309 buf[0] = '\0'; /* no file name */
314 * given that all random loads just fail if the file can't be seen on a
315 * stat, we stat the file we're returning, if it fails, use /dev/arandom
316 * instead. this allows the user to use their own source for good random
317 * data, but defaults to something hopefully decent if that isn't
322 if (BUF_strlcpy(buf, "/dev/arandom", size) >= size) {
325 if (stat(buf, &sb) == -1)
326 if (BUF_strlcpy(buf, "/dev/arandom", size) >= size) {