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 #ifdef MAC_OS_pre_X 79 # include <stat.h> 80 #else 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 struct stat sb; 115 int i,ret=0,n; 116 FILE *in; 117 118 if (file == NULL) return(0); 119 120 if (stat(file,&sb) < 0) return(0); 121 RAND_add(&sb,sizeof(sb),0.0); 122 if (bytes == 0) return(ret); 123 124 #ifdef OPENSSL_SYS_VMS 125 in=vms_fopen(file,"rb",VMS_OPEN_ATTRS); 126 #else 127 in=fopen(file,"rb"); 128 #endif 129 if (in == NULL) goto err; 130 #if defined(S_IFBLK) && defined(S_IFCHR) 131 if (sb.st_mode & (S_IFBLK | S_IFCHR)) { 132 /* this file is a device. we don't want read an infinite number 133 * of bytes from a random device, nor do we want to use buffered 134 * I/O because we will waste system entropy. 135 */ 136 bytes = (bytes == -1) ? 2048 : bytes; /* ok, is 2048 enough? */ 137 setvbuf(in, NULL, _IONBF, 0); /* don't do buffered reads */ 138 } 139 #endif 140 for (;;) 141 { 142 if (bytes > 0) 143 n = (bytes < BUFSIZE)?(int)bytes:BUFSIZE; 144 else 145 n = BUFSIZE; 146 i=fread(buf,1,n,in); 147 if (i <= 0) break; 148 #ifdef PURIFY 149 RAND_add(buf,i,(double)i); 150 #else 151 /* even if n != i, use the full array */ 152 RAND_add(buf,n,(double)i); 153 #endif 154 ret+=i; 155 if (bytes > 0) 156 { 157 bytes-=n; 158 if (bytes <= 0) break; 159 } 160 } 161 fclose(in); 162 OPENSSL_cleanse(buf,BUFSIZE); 163 err: 164 return(ret); 165 } 166 167 int RAND_write_file(const char *file) 168 { 169 unsigned char buf[BUFSIZE]; 170 int i,ret=0,rand_err=0; 171 FILE *out = NULL; 172 int n; 173 struct stat sb; 174 175 i=stat(file,&sb); 176 if (i != -1) { 177 #if defined(S_IFBLK) && defined(S_IFCHR) 178 if (sb.st_mode & (S_IFBLK | S_IFCHR)) { 179 /* this file is a device. we don't write back to it. 180 * we "succeed" on the assumption this is some sort 181 * of random device. Otherwise attempting to write to 182 * and chmod the device causes problems. 183 */ 184 return(1); 185 } 186 #endif 187 } 188 189 #if defined(O_CREAT) && !defined(OPENSSL_SYS_WIN32) && !defined(OPENSSL_SYS_VMS) 190 { 191 /* For some reason Win32 can't write to files created this way */ 192 193 /* chmod(..., 0600) is too late to protect the file, 194 * permissions should be restrictive from the start */ 195 int fd = open(file, O_CREAT, 0600); 196 if (fd != -1) 197 out = fdopen(fd, "wb"); 198 } 199 #endif 200 201 #ifdef OPENSSL_SYS_VMS 202 /* VMS NOTE: Prior versions of this routine created a _new_ 203 * version of the rand file for each call into this routine, then 204 * deleted all existing versions named ;-1, and finally renamed 205 * the current version as ';1'. Under concurrent usage, this 206 * resulted in an RMS race condition in rename() which could 207 * orphan files (see vms message help for RMS$_REENT). With the 208 * fopen() calls below, openssl/VMS now shares the top-level 209 * version of the rand file. Note that there may still be 210 * conditions where the top-level rand file is locked. If so, this 211 * code will then create a new version of the rand file. Without 212 * the delete and rename code, this can result in ascending file 213 * versions that stop at version 32767, and this routine will then 214 * return an error. The remedy for this is to recode the calling 215 * application to avoid concurrent use of the rand file, or 216 * synchronize usage at the application level. Also consider 217 * whether or not you NEED a persistent rand file in a concurrent 218 * use situation. 219 */ 220 221 out = vms_fopen(file,"rb+",VMS_OPEN_ATTRS); 222 if (out == NULL) 223 out = vms_fopen(file,"wb",VMS_OPEN_ATTRS); 224 #else 225 if (out == NULL) 226 out = fopen(file,"wb"); 227 #endif 228 if (out == NULL) goto err; 229 230 #ifndef NO_CHMOD 231 chmod(file,0600); 232 #endif 233 n=RAND_DATA; 234 for (;;) 235 { 236 i=(n > BUFSIZE)?BUFSIZE:n; 237 n-=BUFSIZE; 238 if (RAND_bytes(buf,i) <= 0) 239 rand_err=1; 240 i=fwrite(buf,1,i,out); 241 if (i <= 0) 242 { 243 ret=0; 244 break; 245 } 246 ret+=i; 247 if (n <= 0) break; 248 } 249 250 fclose(out); 251 OPENSSL_cleanse(buf,BUFSIZE); 252 err: 253 return (rand_err ? -1 : ret); 254 } 255 256 const char *RAND_file_name(char *buf, size_t size) 257 { 258 char *s=NULL; 259 int ok = 0; 260 #ifdef __OpenBSD__ 261 struct stat sb; 262 #endif 263 264 if (OPENSSL_issetugid() == 0) 265 s=getenv("RANDFILE"); 266 if (s != NULL && *s && strlen(s) + 1 < size) 267 { 268 if (BUF_strlcpy(buf,s,size) >= size) 269 return NULL; 270 } 271 else 272 { 273 if (OPENSSL_issetugid() == 0) 274 s=getenv("HOME"); 275 #ifdef DEFAULT_HOME 276 if (s == NULL) 277 { 278 s = DEFAULT_HOME; 279 } 280 #endif 281 if (s && *s && strlen(s)+strlen(RFILE)+2 < size) 282 { 283 BUF_strlcpy(buf,s,size); 284 #ifndef OPENSSL_SYS_VMS 285 BUF_strlcat(buf,"/",size); 286 #endif 287 BUF_strlcat(buf,RFILE,size); 288 ok = 1; 289 } 290 else 291 buf[0] = '\0'; /* no file name */ 292 } 293 294 #ifdef __OpenBSD__ 295 /* given that all random loads just fail if the file can't be 296 * seen on a stat, we stat the file we're returning, if it 297 * fails, use /dev/arandom instead. this allows the user to 298 * use their own source for good random data, but defaults 299 * to something hopefully decent if that isn't available. 300 */ 301 302 if (!ok) 303 if (BUF_strlcpy(buf,"/dev/arandom",size) >= size) { 304 return(NULL); 305 } 306 if (stat(buf,&sb) == -1) 307 if (BUF_strlcpy(buf,"/dev/arandom",size) >= size) { 308 return(NULL); 309 } 310 311 #endif 312 return(buf); 313 } 314