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 #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; 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 } 178 179 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 } 327
