randfile.c revision 160815
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 93int 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 i=stat(file,&sb); 106 /* If the state fails, put some crap in anyway */ 107 RAND_add(&sb,sizeof(sb),0.0); 108 if (i < 0) return(0); 109 if (bytes == 0) return(ret); 110 111 in=fopen(file,"rb"); 112 if (in == NULL) goto err; 113#if defined(S_IFBLK) && defined(S_IFCHR) 114 if (sb.st_mode & (S_IFBLK | S_IFCHR)) { 115 /* this file is a device. we don't want read an infinite number 116 * of bytes from a random device, nor do we want to use buffered 117 * I/O because we will waste system entropy. 118 */ 119 bytes = (bytes == -1) ? 2048 : bytes; /* ok, is 2048 enough? */ 120 setvbuf(in, NULL, _IONBF, 0); /* don't do buffered reads */ 121 } 122#endif 123 for (;;) 124 { 125 if (bytes > 0) 126 n = (bytes < BUFSIZE)?(int)bytes:BUFSIZE; 127 else 128 n = BUFSIZE; 129 i=fread(buf,1,n,in); 130 if (i <= 0) break; 131 /* even if n != i, use the full array */ 132 RAND_add(buf,n,(double)i); 133 ret+=i; 134 if (bytes > 0) 135 { 136 bytes-=n; 137 if (bytes <= 0) break; 138 } 139 } 140 fclose(in); 141 OPENSSL_cleanse(buf,BUFSIZE); 142err: 143 return(ret); 144 } 145 146int RAND_write_file(const char *file) 147 { 148 unsigned char buf[BUFSIZE]; 149 int i,ret=0,rand_err=0; 150 FILE *out = NULL; 151 int n; 152 struct stat sb; 153 154 i=stat(file,&sb); 155 if (i != -1) { 156#if defined(S_IFBLK) && defined(S_IFCHR) 157 if (sb.st_mode & (S_IFBLK | S_IFCHR)) { 158 /* this file is a device. we don't write back to it. 159 * we "succeed" on the assumption this is some sort 160 * of random device. Otherwise attempting to write to 161 * and chmod the device causes problems. 162 */ 163 return(1); 164 } 165#endif 166 } 167 168#if defined(O_CREAT) && !defined(OPENSSL_SYS_WIN32) 169 { 170 /* For some reason Win32 can't write to files created this way */ 171 172 /* chmod(..., 0600) is too late to protect the file, 173 * permissions should be restrictive from the start */ 174 int fd = open(file, O_CREAT, 0600); 175 if (fd != -1) 176 out = fdopen(fd, "wb"); 177 } 178#endif 179 if (out == NULL) 180 out = fopen(file,"wb"); 181 if (out == NULL) goto err; 182 183#ifndef NO_CHMOD 184 chmod(file,0600); 185#endif 186 n=RAND_DATA; 187 for (;;) 188 { 189 i=(n > BUFSIZE)?BUFSIZE:n; 190 n-=BUFSIZE; 191 if (RAND_bytes(buf,i) <= 0) 192 rand_err=1; 193 i=fwrite(buf,1,i,out); 194 if (i <= 0) 195 { 196 ret=0; 197 break; 198 } 199 ret+=i; 200 if (n <= 0) break; 201 } 202#ifdef OPENSSL_SYS_VMS 203 /* Try to delete older versions of the file, until there aren't 204 any */ 205 { 206 char *tmpf; 207 208 tmpf = OPENSSL_malloc(strlen(file) + 4); /* to add ";-1" and a nul */ 209 if (tmpf) 210 { 211 strcpy(tmpf, file); 212 strcat(tmpf, ";-1"); 213 while(delete(tmpf) == 0) 214 ; 215 rename(file,";1"); /* Make sure it's version 1, or we 216 will reach the limit (32767) at 217 some point... */ 218 } 219 } 220#endif /* OPENSSL_SYS_VMS */ 221 222 fclose(out); 223 OPENSSL_cleanse(buf,BUFSIZE); 224err: 225 return (rand_err ? -1 : ret); 226 } 227 228const char *RAND_file_name(char *buf, size_t size) 229 { 230 char *s=NULL; 231 int ok = 0; 232#ifdef __OpenBSD__ 233 struct stat sb; 234#endif 235 236 if (OPENSSL_issetugid() == 0) 237 s=getenv("RANDFILE"); 238 if (s != NULL && *s && strlen(s) + 1 < size) 239 { 240 if (BUF_strlcpy(buf,s,size) >= size) 241 return NULL; 242 } 243 else 244 { 245 if (OPENSSL_issetugid() == 0) 246 s=getenv("HOME"); 247#ifdef DEFAULT_HOME 248 if (s == NULL) 249 { 250 s = DEFAULT_HOME; 251 } 252#endif 253 if (s && *s && strlen(s)+strlen(RFILE)+2 < size) 254 { 255 BUF_strlcpy(buf,s,size); 256#ifndef OPENSSL_SYS_VMS 257 BUF_strlcat(buf,"/",size); 258#endif 259 BUF_strlcat(buf,RFILE,size); 260 ok = 1; 261 } 262 else 263 buf[0] = '\0'; /* no file name */ 264 } 265 266#ifdef __OpenBSD__ 267 /* given that all random loads just fail if the file can't be 268 * seen on a stat, we stat the file we're returning, if it 269 * fails, use /dev/arandom instead. this allows the user to 270 * use their own source for good random data, but defaults 271 * to something hopefully decent if that isn't available. 272 */ 273 274 if (!ok) 275 if (BUF_strlcpy(buf,"/dev/arandom",size) >= size) { 276 return(NULL); 277 } 278 if (stat(buf,&sb) == -1) 279 if (BUF_strlcpy(buf,"/dev/arandom",size) >= size) { 280 return(NULL); 281 } 282 283#endif 284 return(buf); 285 } 286