Alexandre Savard | 1b09e31 | 2012-08-07 20:33:29 -0400 | [diff] [blame] | 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 | |
| 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; |
Alexandre Savard | 7541067 | 2012-08-08 09:50:01 -0400 | [diff] [blame] | 140 | #if defined(S_IFBLK) && defined(S_IFCHR) && !defined(OPNESSL_NO_POSIX_IO) |
Alexandre Savard | 1b09e31 | 2012-08-07 20:33:29 -0400 | [diff] [blame] | 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 | |
| 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 | |
| 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 | } |