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 #undef BUFSIZE 85 #define BUFSIZE 1024 86 #define RAND_DATA 1024 87 88 /* #define RFILE ".rnd" - defined in ../../e_os.h */ 89 90 /* Note that these functions are intended for seed files only. 91 * Entropy devices and EGD sockets are handled in rand_unix.c */ 92 93 int RAND_load_file(const char *file, long bytes) 94 { 95 /* If bytes >= 0, read up to 'bytes' bytes. 96 * if bytes == -1, read complete file. */ 97 98 MS_STATIC unsigned char buf[BUFSIZE]; 99 struct stat sb; 100 int i,ret=0,n; 101 FILE *in; 102 103 if (file == NULL) return(0); 104 105 if (stat(file,&sb) < 0) return(0); 106 RAND_add(&sb,sizeof(sb),0.0); 107 if (bytes == 0) return(ret); 108 109 in=fopen(file,"rb"); 110 if (in == NULL) goto err; 111 #if defined(S_IFBLK) && defined(S_IFCHR) 112 if (sb.st_mode & (S_IFBLK | S_IFCHR)) { 113 /* this file is a device. we don't want read an infinite number 114 * of bytes from a random device, nor do we want to use buffered 115 * I/O because we will waste system entropy. 116 */ 117 bytes = (bytes == -1) ? 2048 : bytes; /* ok, is 2048 enough? */ 118 setvbuf(in, NULL, _IONBF, 0); /* don't do buffered reads */ 119 } 120 #endif 121 for (;;) 122 { 123 if (bytes > 0) 124 n = (bytes < BUFSIZE)?(int)bytes:BUFSIZE; 125 else 126 n = BUFSIZE; 127 i=fread(buf,1,n,in); 128 if (i <= 0) break; 129 #ifdef PURIFY 130 RAND_add(buf,i,(double)i); 131 #else 132 /* even if n != i, use the full array */ 133 RAND_add(buf,n,(double)i); 134 #endif 135 ret+=i; 136 if (bytes > 0) 137 { 138 bytes-=n; 139 if (bytes <= 0) break; 140 } 141 } 142 fclose(in); 143 OPENSSL_cleanse(buf,BUFSIZE); 144 err: 145 return(ret); 146 } 147 148 int RAND_write_file(const char *file) 149 { 150 unsigned char buf[BUFSIZE]; 151 int i,ret=0,rand_err=0; 152 FILE *out = NULL; 153 int n; 154 struct stat sb; 155 156 i=stat(file,&sb); 157 if (i != -1) { 158 #if defined(S_IFBLK) && defined(S_IFCHR) 159 if (sb.st_mode & (S_IFBLK | S_IFCHR)) { 160 /* this file is a device. we don't write back to it. 161 * we "succeed" on the assumption this is some sort 162 * of random device. Otherwise attempting to write to 163 * and chmod the device causes problems. 164 */ 165 return(1); 166 } 167 #endif 168 } 169 170 #if defined(O_CREAT) && !defined(OPENSSL_SYS_WIN32) 171 { 172 /* For some reason Win32 can't write to files created this way */ 173 174 /* chmod(..., 0600) is too late to protect the file, 175 * permissions should be restrictive from the start */ 176 int fd = open(file, O_CREAT, 0600); 177 if (fd != -1) 178 out = fdopen(fd, "wb"); 179 } 180 #endif 181 if (out == NULL) 182 out = fopen(file,"wb"); 183 if (out == NULL) goto err; 184 185 #ifndef NO_CHMOD 186 chmod(file,0600); 187 #endif 188 n=RAND_DATA; 189 for (;;) 190 { 191 i=(n > BUFSIZE)?BUFSIZE:n; 192 n-=BUFSIZE; 193 if (RAND_bytes(buf,i) <= 0) 194 rand_err=1; 195 i=fwrite(buf,1,i,out); 196 if (i <= 0) 197 { 198 ret=0; 199 break; 200 } 201 ret+=i; 202 if (n <= 0) break; 203 } 204 #ifdef OPENSSL_SYS_VMS 205 /* Try to delete older versions of the file, until there aren't 206 any */ 207 { 208 char *tmpf; 209 210 tmpf = OPENSSL_malloc(strlen(file) + 4); /* to add ";-1" and a nul */ 211 if (tmpf) 212 { 213 strcpy(tmpf, file); 214 strcat(tmpf, ";-1"); 215 while(delete(tmpf) == 0) 216 ; 217 rename(file,";1"); /* Make sure it's version 1, or we 218 will reach the limit (32767) at 219 some point... */ 220 } 221 } 222 #endif /* OPENSSL_SYS_VMS */ 223 224 fclose(out); 225 OPENSSL_cleanse(buf,BUFSIZE); 226 err: 227 return (rand_err ? -1 : ret); 228 } 229 230 const char *RAND_file_name(char *buf, size_t size) 231 { 232 char *s=NULL; 233 int ok = 0; 234 #ifdef __OpenBSD__ 235 struct stat sb; 236 #endif 237 238 if (issetugid() == 0) 239 s=getenv("RANDFILE"); 240 if (s != NULL && *s && strlen(s) + 1 < size) 241 { 242 if (BUF_strlcpy(buf,s,size) >= size) 243 return NULL; 244 } 245 else 246 { 247 if (issetugid() == 0) 248 s=getenv("HOME"); 249 #ifdef DEFAULT_HOME 250 if (s == NULL) 251 { 252 s = DEFAULT_HOME; 253 } 254 #endif 255 if (s && *s && strlen(s)+strlen(RFILE)+2 < size) 256 { 257 BUF_strlcpy(buf,s,size); 258 #ifndef OPENSSL_SYS_VMS 259 BUF_strlcat(buf,"/",size); 260 #endif 261 BUF_strlcat(buf,RFILE,size); 262 ok = 1; 263 } 264 else 265 buf[0] = '\0'; /* no file name */ 266 } 267 268 #ifdef __OpenBSD__ 269 /* given that all random loads just fail if the file can't be 270 * seen on a stat, we stat the file we're returning, if it 271 * fails, use /dev/arandom instead. this allows the user to 272 * use their own source for good random data, but defaults 273 * to something hopefully decent if that isn't available. 274 */ 275 276 if (!ok) 277 if (BUF_strlcpy(buf,"/dev/arandom",size) >= size) { 278 return(NULL); 279 } 280 if (stat(buf,&sb) == -1) 281 if (BUF_strlcpy(buf,"/dev/arandom",size) >= size) { 282 return(NULL); 283 } 284 285 #endif 286 return(buf); 287 } 288