randfile.c 8.0 KB

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  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. /* We need to define this to get macros like S_IFBLK and S_IFCHR */
  59. #define _XOPEN_SOURCE 500
  60. #include <errno.h>
  61. #include <stdio.h>
  62. #include <stdlib.h>
  63. #include <string.h>
  64. #include "e_os.h"
  65. #include <openssl/crypto.h>
  66. #include <openssl/rand.h>
  67. #include <openssl/buffer.h>
  68. #ifdef OPENSSL_SYS_VMS
  69. #include <unixio.h>
  70. #endif
  71. #ifndef NO_SYS_TYPES_H
  72. # include <sys/types.h>
  73. #endif
  74. #ifndef OPENSSL_NO_POSIX_IO
  75. # include <sys/stat.h>
  76. #endif
  77. #undef BUFSIZE
  78. #define BUFSIZE 1024
  79. #define RAND_DATA 1024
  80. /* #define RFILE ".rnd" - defined in ../../e_os.h */
  81. /* Note that these functions are intended for seed files only.
  82. * Entropy devices and EGD sockets are handled in rand_unix.c */
  83. int RAND_load_file(const char *file, long bytes)
  84. {
  85. /* If bytes >= 0, read up to 'bytes' bytes.
  86. * if bytes == -1, read complete file. */
  87. MS_STATIC unsigned char buf[BUFSIZE];
  88. #ifndef OPENSSL_NO_POSIX_IO
  89. struct stat sb;
  90. #endif
  91. int i,ret=0,n;
  92. FILE *in;
  93. if (file == NULL) return(0);
  94. #ifndef OPENSSL_NO_POSIX_IO
  95. if (stat(file,&sb) < 0) return(0);
  96. RAND_add(&sb,sizeof(sb),0.0);
  97. #endif
  98. if (bytes == 0) return(ret);
  99. in=fopen(file,"rb");
  100. if (in == NULL) goto err;
  101. #if defined(S_IFBLK) && defined(S_IFCHR) && !defined(OPNESSL_NO_POSIX_IO)
  102. if (sb.st_mode & (S_IFBLK | S_IFCHR)) {
  103. /* this file is a device. we don't want read an infinite number
  104. * of bytes from a random device, nor do we want to use buffered
  105. * I/O because we will waste system entropy.
  106. */
  107. bytes = (bytes == -1) ? 2048 : bytes; /* ok, is 2048 enough? */
  108. setvbuf(in, NULL, _IONBF, 0); /* don't do buffered reads */
  109. }
  110. #endif
  111. for (;;)
  112. {
  113. if (bytes > 0)
  114. n = (bytes < BUFSIZE)?(int)bytes:BUFSIZE;
  115. else
  116. n = BUFSIZE;
  117. i=fread(buf,1,n,in);
  118. if (i <= 0) break;
  119. #ifdef PURIFY
  120. RAND_add(buf,i,(double)i);
  121. #else
  122. /* even if n != i, use the full array */
  123. RAND_add(buf,n,(double)i);
  124. #endif
  125. ret+=i;
  126. if (bytes > 0)
  127. {
  128. bytes-=n;
  129. if (bytes <= 0) break;
  130. }
  131. }
  132. fclose(in);
  133. OPENSSL_cleanse(buf,BUFSIZE);
  134. err:
  135. return(ret);
  136. }
  137. int RAND_write_file(const char *file)
  138. {
  139. unsigned char buf[BUFSIZE];
  140. int i,ret=0,rand_err=0;
  141. FILE *out = NULL;
  142. int n;
  143. #ifndef OPENSSL_NO_POSIX_IO
  144. struct stat sb;
  145. i=stat(file,&sb);
  146. if (i != -1) {
  147. #if defined(S_IFBLK) && defined(S_IFCHR)
  148. if (sb.st_mode & (S_IFBLK | S_IFCHR)) {
  149. /* this file is a device. we don't write back to it.
  150. * we "succeed" on the assumption this is some sort
  151. * of random device. Otherwise attempting to write to
  152. * and chmod the device causes problems.
  153. */
  154. return(1);
  155. }
  156. #endif
  157. }
  158. #endif
  159. #if defined(O_CREAT) && !defined(OPENSSL_SYS_WIN32) && !defined(OPENSSL_NO_POSIX_IO)
  160. {
  161. /* For some reason Win32 can't write to files created this way */
  162. /* chmod(..., 0600) is too late to protect the file,
  163. * permissions should be restrictive from the start */
  164. int fd = open(file, O_CREAT, 0600);
  165. if (fd != -1)
  166. out = fdopen(fd, "wb");
  167. }
  168. #endif
  169. if (out == NULL)
  170. out = fopen(file,"wb");
  171. if (out == NULL) goto err;
  172. #ifndef NO_CHMOD
  173. chmod(file,0600);
  174. #endif
  175. n=RAND_DATA;
  176. for (;;)
  177. {
  178. i=(n > BUFSIZE)?BUFSIZE:n;
  179. n-=BUFSIZE;
  180. if (RAND_bytes(buf,i) <= 0)
  181. rand_err=1;
  182. i=fwrite(buf,1,i,out);
  183. if (i <= 0)
  184. {
  185. ret=0;
  186. break;
  187. }
  188. ret+=i;
  189. if (n <= 0) break;
  190. }
  191. #ifdef OPENSSL_SYS_VMS
  192. /* Try to delete older versions of the file, until there aren't
  193. any */
  194. {
  195. char *tmpf;
  196. tmpf = OPENSSL_malloc(strlen(file) + 4); /* to add ";-1" and a nul */
  197. if (tmpf)
  198. {
  199. strcpy(tmpf, file);
  200. strcat(tmpf, ";-1");
  201. while(delete(tmpf) == 0)
  202. ;
  203. rename(file,";1"); /* Make sure it's version 1, or we
  204. will reach the limit (32767) at
  205. some point... */
  206. }
  207. }
  208. #endif /* OPENSSL_SYS_VMS */
  209. fclose(out);
  210. OPENSSL_cleanse(buf,BUFSIZE);
  211. err:
  212. return (rand_err ? -1 : ret);
  213. }
  214. const char *RAND_file_name(char *buf, size_t size)
  215. {
  216. char *s=NULL;
  217. int ok = 0;
  218. #ifdef __OpenBSD__
  219. struct stat sb;
  220. #endif
  221. if (OPENSSL_issetugid() == 0)
  222. s=getenv("RANDFILE");
  223. if (s != NULL && *s && strlen(s) + 1 < size)
  224. {
  225. if (BUF_strlcpy(buf,s,size) >= size)
  226. return NULL;
  227. }
  228. else
  229. {
  230. if (OPENSSL_issetugid() == 0)
  231. s=getenv("HOME");
  232. #ifdef DEFAULT_HOME
  233. if (s == NULL)
  234. {
  235. s = DEFAULT_HOME;
  236. }
  237. #endif
  238. if (s && *s && strlen(s)+strlen(RFILE)+2 < size)
  239. {
  240. BUF_strlcpy(buf,s,size);
  241. #ifndef OPENSSL_SYS_VMS
  242. BUF_strlcat(buf,"/",size);
  243. #endif
  244. BUF_strlcat(buf,RFILE,size);
  245. ok = 1;
  246. }
  247. else
  248. buf[0] = '\0'; /* no file name */
  249. }
  250. #ifdef __OpenBSD__
  251. /* given that all random loads just fail if the file can't be
  252. * seen on a stat, we stat the file we're returning, if it
  253. * fails, use /dev/arandom instead. this allows the user to
  254. * use their own source for good random data, but defaults
  255. * to something hopefully decent if that isn't available.
  256. */
  257. if (!ok)
  258. if (BUF_strlcpy(buf,"/dev/arandom",size) >= size) {
  259. return(NULL);
  260. }
  261. if (stat(buf,&sb) == -1)
  262. if (BUF_strlcpy(buf,"/dev/arandom",size) >= size) {
  263. return(NULL);
  264. }
  265. #endif
  266. return(buf);
  267. }