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 #include "e_os.h" 65 #include <openssl/crypto.h> 66 #include <openssl/rand.h> 67 68 #ifdef OPENSSL_SYS_VMS 69 #include <unixio.h> 70 #endif 71 #ifndef NO_SYS_TYPES_H 72 # include <sys/types.h> 73 #endif 74 #ifdef MAC_OS_pre_X 75 # include <stat.h> 76 #else 77 # include <sys/stat.h> 78 #endif 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 the state fails, put some crap in anyway */ 103 RAND_add(&sb,sizeof(sb),0); 104 if (i < 0) return(0); 105 if (bytes == 0) return(ret); 106 107 in=fopen(file,"rb"); 108 if (in == NULL) goto err; 109 if (sb.st_mode & (S_IFBLK | S_IFCHR)) { 110 /* this file is a device. we don't want read an infinite number 111 * of bytes from a random device, nor do we want to use buffered 112 * I/O because we will waste system entropy. 113 */ 114 bytes = (bytes == -1) ? 2048 : bytes; /* ok, is 2048 enough? */ 115 setvbuf(in, NULL, _IONBF, 0); /* don't do buffered reads */ 116 } 117 for (;;) 118 { 119 if (bytes > 0) 120 n = (bytes < BUFSIZE)?(int)bytes:BUFSIZE; 121 else 122 n = BUFSIZE; 123 i=fread(buf,1,n,in); 124 if (i <= 0) break; 125 /* even if n != i, use the full array */ 126 RAND_add(buf,n,i); 127 ret+=i; 128 if (bytes > 0) 129 { 130 bytes-=n; 131 if (bytes <= 0) break; 132 } 133 } 134 fclose(in); 135 OPENSSL_cleanse(buf,BUFSIZE); 136 err: 137 return(ret); 138 } 139 140 int RAND_write_file(const char *file) 141 { 142 unsigned char buf[BUFSIZE]; 143 int i,ret=0,rand_err=0; 144 FILE *out = NULL; 145 int n; 146 struct stat sb; 147 148 i=stat(file,&sb); 149 if (i != -1) { 150 if (sb.st_mode & (S_IFBLK | S_IFCHR)) { 151 /* this file is a device. we don't write back to it. 152 * we "succeed" on the assumption this is some sort 153 * of random device. Otherwise attempting to write to 154 * and chmod the device causes problems. 155 */ 156 return(1); 157 } 158 } 159 160 #if defined(O_CREAT) && !defined(OPENSSL_SYS_WIN32) 161 /* For some reason Win32 can't write to files created this way */ 162 163 /* chmod(..., 0600) is too late to protect the file, 164 * permissions should be restrictive from the start */ 165 int fd = open(file, O_CREAT, 0600); 166 if (fd != -1) 167 out = fdopen(fd, "wb"); 168 #endif 169 if (out == NULL) 170 out = fopen(file,"wb"); 171 if (out == NULL) goto err; 172 173 #ifndef NO_CHMOD 174 chmod(file,0600); 175 #endif 176 n=RAND_DATA; 177 for (;;) 178 { 179 i=(n > BUFSIZE)?BUFSIZE:n; 180 n-=BUFSIZE; 181 if (RAND_bytes(buf,i) <= 0) 182 rand_err=1; 183 i=fwrite(buf,1,i,out); 184 if (i <= 0) 185 { 186 ret=0; 187 break; 188 } 189 ret+=i; 190 if (n <= 0) break; 191 } 192 #ifdef OPENSSL_SYS_VMS 193 /* Try to delete older versions of the file, until there aren't 194 any */ 195 { 196 char *tmpf; 197 198 tmpf = OPENSSL_malloc(strlen(file) + 4); /* to add ";-1" and a nul */ 199 if (tmpf) 200 { 201 strcpy(tmpf, file); 202 strcat(tmpf, ";-1"); 203 while(delete(tmpf) == 0) 204 ; 205 rename(file,";1"); /* Make sure it's version 1, or we 206 will reach the limit (32767) at 207 some point... */ 208 } 209 } 210 #endif /* OPENSSL_SYS_VMS */ 211 212 fclose(out); 213 OPENSSL_cleanse(buf,BUFSIZE); 214 err: 215 return (rand_err ? -1 : ret); 216 } 217 218 const char *RAND_file_name(char *buf, size_t size) 219 { 220 char *s=NULL; 221 int ok = 0; 222 struct stat sb; 223 224 if (issetugid() == 0) 225 s=getenv("RANDFILE"); 226 if (s != NULL && *s && strlen(s) + 1 < size) 227 { 228 if (strlcpy(buf,s,size) >= size) 229 return NULL; 230 } 231 else 232 { 233 if (issetugid() == 0) 234 s=getenv("HOME"); 235 #ifdef DEFAULT_HOME 236 if (s == NULL) 237 { 238 s = DEFAULT_HOME; 239 } 240 #endif 241 if (s && *s && strlen(s)+strlen(RFILE)+2 < size) 242 { 243 strlcpy(buf,s,size); 244 #ifndef OPENSSL_SYS_VMS 245 strlcat(buf,"/",size); 246 #endif 247 strlcat(buf,RFILE,size); 248 ok = 1; 249 } 250 else 251 buf[0] = '\0'; /* no file name */ 252 } 253 254 #ifdef __OpenBSD__ 255 /* given that all random loads just fail if the file can't be 256 * seen on a stat, we stat the file we're returning, if it 257 * fails, use /dev/arandom instead. this allows the user to 258 * use their own source for good random data, but defaults 259 * to something hopefully decent if that isn't available. 260 */ 261 262 if (!ok) 263 if (strlcpy(buf,"/dev/arandom",size) >= size) { 264 return(NULL); 265 } 266 if (stat(buf,&sb) == -1) 267 if (strlcpy(buf,"/dev/arandom",size) >= size) { 268 return(NULL); 269 } 270 271 #endif 272 return(buf); 273 } 274