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