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#ifndef OPENSSL_NO_POSIX_IO 79# include <sys/stat.h> 80#endif 81 82#ifdef _WIN32 83#define stat _stat 84#define chmod _chmod 85#define open _open 86#define fdopen _fdopen 87#endif 88 89#undef BUFSIZE 90#define BUFSIZE 1024 91#define RAND_DATA 1024 92 93#ifdef OPENSSL_SYS_VMS 94/* This declaration is a nasty hack to get around vms' extension to fopen 95 * for passing in sharing options being disabled by our /STANDARD=ANSI89 */ 96static FILE *(*const vms_fopen)(const char *, const char *, ...) = 97 (FILE *(*)(const char *, const char *, ...))fopen; 98#define VMS_OPEN_ATTRS "shr=get,put,upd,del","ctx=bin,stm","rfm=stm","rat=none","mrs=0" 99#endif 100 101/* #define RFILE ".rnd" - defined in ../../e_os.h */ 102 103/* Note that these functions are intended for seed files only. 104 * Entropy devices and EGD sockets are handled in rand_unix.c */ 105 106int RAND_load_file(const char *file, long bytes) 107 { 108 /* If bytes >= 0, read up to 'bytes' bytes. 109 * if bytes == -1, read complete file. */ 110 111 MS_STATIC unsigned char buf[BUFSIZE]; 112#ifndef OPENSSL_NO_POSIX_IO 113 struct stat sb; 114#endif 115 int i,ret=0,n; 116 FILE *in; 117 118 if (file == NULL) return(0); 119 120#ifndef OPENSSL_NO_POSIX_IO 121#ifdef PURIFY 122 /* struct stat can have padding and unused fields that may not be 123 * initialized in the call to stat(). We need to clear the entire 124 * structure before calling RAND_add() to avoid complaints from 125 * applications such as Valgrind. 126 */ 127 memset(&sb, 0, sizeof(sb)); 128#endif 129 if (stat(file,&sb) < 0) return(0); 130 RAND_add(&sb,sizeof(sb),0.0); 131#endif 132 if (bytes == 0) return(ret); 133 134#ifdef OPENSSL_SYS_VMS 135 in=vms_fopen(file,"rb",VMS_OPEN_ATTRS); 136#else 137 in=fopen(file,"rb"); 138#endif 139 if (in == NULL) goto err; 140#if defined(S_IFBLK) && defined(S_IFCHR) && !defined(OPNESSL_NO_POSIX_IO) 141 if (sb.st_mode & (S_IFBLK | S_IFCHR)) { 142 /* this file is a device. we don't want read an infinite number 143 * of bytes from a random device, nor do we want to use buffered 144 * I/O because we will waste system entropy. 145 */ 146 bytes = (bytes == -1) ? 2048 : bytes; /* ok, is 2048 enough? */ 147 setvbuf(in, NULL, _IONBF, 0); /* don't do buffered reads */ 148 } 149#endif 150 for (;;) 151 { 152 if (bytes > 0) 153 n = (bytes < BUFSIZE)?(int)bytes:BUFSIZE; 154 else 155 n = BUFSIZE; 156 i=fread(buf,1,n,in); 157 if (i <= 0) break; 158#ifdef PURIFY 159 RAND_add(buf,i,(double)i); 160#else 161 /* even if n != i, use the full array */ 162 RAND_add(buf,n,(double)i); 163#endif 164 ret+=i; 165 if (bytes > 0) 166 { 167 bytes-=n; 168 if (bytes <= 0) break; 169 } 170 } 171 fclose(in); 172 OPENSSL_cleanse(buf,BUFSIZE); 173err: 174 return(ret); 175 } 176 177int RAND_write_file(const char *file) 178 { 179 unsigned char buf[BUFSIZE]; 180 int i,ret=0,rand_err=0; 181 FILE *out = NULL; 182 int n; 183#ifndef OPENSSL_NO_POSIX_IO 184 struct stat sb; 185 186 i=stat(file,&sb); 187 if (i != -1) { 188#if defined(S_ISBLK) && defined(S_ISCHR) 189 if (S_ISBLK(sb.st_mode) || S_ISCHR(sb.st_mode)) { 190 /* this file is a device. we don't write back to it. 191 * we "succeed" on the assumption this is some sort 192 * of random device. Otherwise attempting to write to 193 * and chmod the device causes problems. 194 */ 195 return(1); 196 } 197#endif 198 } 199#endif 200 201#if defined(O_CREAT) && !defined(OPENSSL_NO_POSIX_IO) && !defined(OPENSSL_SYS_VMS) 202 { 203#ifndef O_BINARY 204#define O_BINARY 0 205#endif 206 /* chmod(..., 0600) is too late to protect the file, 207 * permissions should be restrictive from the start */ 208 int fd = open(file, O_WRONLY|O_CREAT|O_BINARY, 0600); 209 if (fd != -1) 210 out = fdopen(fd, "wb"); 211 } 212#endif 213 214#ifdef OPENSSL_SYS_VMS 215 /* VMS NOTE: Prior versions of this routine created a _new_ 216 * version of the rand file for each call into this routine, then 217 * deleted all existing versions named ;-1, and finally renamed 218 * the current version as ';1'. Under concurrent usage, this 219 * resulted in an RMS race condition in rename() which could 220 * orphan files (see vms message help for RMS$_REENT). With the 221 * fopen() calls below, openssl/VMS now shares the top-level 222 * version of the rand file. Note that there may still be 223 * conditions where the top-level rand file is locked. If so, this 224 * code will then create a new version of the rand file. Without 225 * the delete and rename code, this can result in ascending file 226 * versions that stop at version 32767, and this routine will then 227 * return an error. The remedy for this is to recode the calling 228 * application to avoid concurrent use of the rand file, or 229 * synchronize usage at the application level. Also consider 230 * whether or not you NEED a persistent rand file in a concurrent 231 * use situation. 232 */ 233 234 out = vms_fopen(file,"rb+",VMS_OPEN_ATTRS); 235 if (out == NULL) 236 out = vms_fopen(file,"wb",VMS_OPEN_ATTRS); 237#else 238 if (out == NULL) 239 out = fopen(file,"wb"); 240#endif 241 if (out == NULL) goto err; 242 243#ifndef NO_CHMOD 244 chmod(file,0600); 245#endif 246 n=RAND_DATA; 247 for (;;) 248 { 249 i=(n > BUFSIZE)?BUFSIZE:n; 250 n-=BUFSIZE; 251 if (RAND_bytes(buf,i) <= 0) 252 rand_err=1; 253 i=fwrite(buf,1,i,out); 254 if (i <= 0) 255 { 256 ret=0; 257 break; 258 } 259 ret+=i; 260 if (n <= 0) break; 261 } 262 263 fclose(out); 264 OPENSSL_cleanse(buf,BUFSIZE); 265err: 266 return (rand_err ? -1 : ret); 267 } 268 269const char *RAND_file_name(char *buf, size_t size) 270 { 271 char *s=NULL; 272#ifdef __OpenBSD__ 273 struct stat sb; 274#endif 275 276 if (OPENSSL_issetugid() == 0) 277 s=getenv("RANDFILE"); 278 if (s != NULL && *s && strlen(s) + 1 < size) 279 { 280 if (BUF_strlcpy(buf,s,size) >= size) 281 return NULL; 282 } 283 else 284 { 285 if (OPENSSL_issetugid() == 0) 286 s=getenv("HOME"); 287#ifdef DEFAULT_HOME 288 if (s == NULL) 289 { 290 s = DEFAULT_HOME; 291 } 292#endif 293 if (s && *s && strlen(s)+strlen(RFILE)+2 < size) 294 { 295 BUF_strlcpy(buf,s,size); 296#ifndef OPENSSL_SYS_VMS 297 BUF_strlcat(buf,"/",size); 298#endif 299 BUF_strlcat(buf,RFILE,size); 300 } 301 else 302 buf[0] = '\0'; /* no file name */ 303 } 304 305#ifdef __OpenBSD__ 306 /* given that all random loads just fail if the file can't be 307 * seen on a stat, we stat the file we're returning, if it 308 * fails, use /dev/arandom instead. this allows the user to 309 * use their own source for good random data, but defaults 310 * to something hopefully decent if that isn't available. 311 */ 312 313 if (!buf[0]) 314 if (BUF_strlcpy(buf,"/dev/arandom",size) >= size) { 315 return(NULL); 316 } 317 if (stat(buf,&sb) == -1) 318 if (BUF_strlcpy(buf,"/dev/arandom",size) >= size) { 319 return(NULL); 320 } 321 322#endif 323 return(buf); 324 } 325