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 #include <errno.h> 60 #include <stdio.h> 61 #include <stdlib.h> 62 #include <string.h> 63 64 #ifdef VMS 65 #include <unixio.h> 66 #endif 67 #ifndef NO_SYS_TYPES_H 68 # include <sys/types.h> 69 #endif 70 #ifdef MAC_OS_pre_X 71 # include <stat.h> 72 #else 73 # include <sys/stat.h> 74 #endif 75 76 #include "openssl/e_os.h" 77 #include <openssl/crypto.h> 78 #include <openssl/rand.h> 79 80 #undef BUFSIZE 81 #define BUFSIZE 1024 82 #define RAND_DATA 1024 83 84 /* #define RFILE ".rnd" - defined in ../../e_os.h */ 85 86 /* Note that these functions are intended for seed files only. 87 * Entropy devices and EGD sockets are handled in rand_unix.c */ 88 89 int RAND_load_file(const char *file, long bytes) 90 { 91 /* If bytes >= 0, read up to 'bytes' bytes. 92 * if bytes == -1, read complete file. */ 93 94 MS_STATIC unsigned char buf[BUFSIZE]; 95 struct stat sb; 96 int i,ret=0,n; 97 FILE *in; 98 99 if (file == NULL) return(0); 100 101 i=stat(file,&sb); 102 if (i < 0) { 103 /* If the state fails, put some crap in anyway */ 104 RAND_add(&sb,sizeof(sb),0); 105 return(0); 106 } 107 if (bytes == 0) return(ret); 108 in=fopen(file,"rb"); 109 if (in == NULL) goto err; 110 if (sb.st_mode & (S_IFBLK | S_IFCHR)) { 111 /* this file is a device. we don't want read an infinite number 112 * of bytes from a random device, nor do we want to use buffered 113 * I/O because we will waste system entropy. 114 */ 115 bytes = (bytes == -1) ? 2048 : bytes; /* ok, is 2048 enough? */ 116 setvbuf(in, NULL, _IONBF, 0); /* don't do buffered reads */ 117 } 118 for (;;) 119 { 120 if (bytes > 0) 121 n = (bytes < BUFSIZE)?(int)bytes:BUFSIZE; 122 else 123 n = BUFSIZE; 124 i=fread(buf,1,n,in); 125 if (i <= 0) break; 126 /* even if n != i, use the full array */ 127 RAND_add(buf,n,i); 128 ret+=i; 129 if (bytes > 0) 130 { 131 bytes-=n; 132 if (bytes <= 0) break; 133 } 134 } 135 fclose(in); 136 memset(buf,0,BUFSIZE); 137 err: 138 return(ret); 139 } 140 141 int RAND_write_file(const char *file) 142 { 143 unsigned char buf[BUFSIZE]; 144 int i,ret=0,rand_err=0; 145 FILE *out = NULL; 146 int n; 147 struct stat sb; 148 149 i=stat(file,&sb); 150 if (i != -1) { 151 if (sb.st_mode & (S_IFBLK | S_IFCHR)) { 152 /* this file is a device. we don't write back to it. 153 * we "succeed" on the assumption this is some sort 154 * of random device. Otherwise attempting to write to 155 * and chmod the device causes problems. 156 */ 157 return(1); 158 } 159 } 160 161 #if defined(O_CREAT) && !defined(WIN32) 162 /* For some reason Win32 can't write to files created this way */ 163 164 /* chmod(..., 0600) is too late to protect the file, 165 * permissions should be restrictive from the start */ 166 int fd = open(file, O_CREAT, 0600); 167 if (fd != -1) 168 out = fdopen(fd, "wb"); 169 #endif 170 if (out == NULL) 171 out = fopen(file,"wb"); 172 if (out == NULL) goto err; 173 174 #ifndef NO_CHMOD 175 chmod(file,0600); 176 #endif 177 n=RAND_DATA; 178 for (;;) 179 { 180 i=(n > BUFSIZE)?BUFSIZE:n; 181 n-=BUFSIZE; 182 if (RAND_bytes(buf,i) <= 0) 183 rand_err=1; 184 i=fwrite(buf,1,i,out); 185 if (i <= 0) 186 { 187 ret=0; 188 break; 189 } 190 ret+=i; 191 if (n <= 0) break; 192 } 193 #ifdef VMS 194 /* Try to delete older versions of the file, until there aren't 195 any */ 196 { 197 char *tmpf; 198 199 tmpf = OPENSSL_malloc(strlen(file) + 4); /* to add ";-1" and a nul */ 200 if (tmpf) 201 { 202 strcpy(tmpf, file); 203 strcat(tmpf, ";-1"); 204 while(delete(tmpf) == 0) 205 ; 206 rename(file,";1"); /* Make sure it's version 1, or we 207 will reach the limit (32767) at 208 some point... */ 209 } 210 } 211 #endif /* VMS */ 212 213 fclose(out); 214 memset(buf,0,BUFSIZE); 215 err: 216 return (rand_err ? -1 : ret); 217 } 218 219 const char *RAND_file_name(char *buf, size_t size) 220 { 221 char *s = NULL; 222 char *ret=NULL; 223 struct stat sb; 224 225 if (issetugid() == 0) 226 s = getenv("RANDFILE"); 227 if (s != NULL && *s && strlen(s) + 1 < size) 228 { 229 strlcpy(buf,s,size); 230 ret=buf; 231 } 232 else 233 { 234 if (issetugid() == 0) 235 s=getenv("HOME"); 236 #ifdef DEFAULT_HOME 237 if (s == NULL) 238 { 239 s = DEFAULT_HOME; 240 } 241 #endif 242 if (s && *s && strlen(s)+strlen(RFILE)+2 < size) 243 { 244 strlcpy(buf,s,size); 245 #ifndef VMS 246 strcat(buf,"/"); 247 #endif 248 strlcat(buf,RFILE,size); 249 ret=buf; 250 } 251 else 252 buf[0] = '\0'; /* no file name */ 253 } 254 255 #ifdef DEVRANDOM 256 /* given that all random loads just fail if the file can't be 257 * seen on a stat, we stat the file we're returning, if it 258 * fails, use DEVRANDOM instead. the allows the user to 259 * use their own source for good random data, but defaults 260 * to something hopefully decent if that isn't available. 261 */ 262 263 if (ret == NULL) 264 ret = DEVRANDOM; 265 266 if (stat(ret,&sb) == -1) 267 ret = DEVRANDOM; 268 #endif 269 return(ret); 270 } 271 272