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#if !defined(OPENSSL_SYS_VXWORKS) 61#define _XOPEN_SOURCE 500 62#endif 63 64#include <errno.h> 65#include <stdio.h> 66#include <stdlib.h> 67#include <string.h> 68 69#include "e_os.h" 70#include <openssl/crypto.h> 71#include <openssl/rand.h> 72#include <openssl/buffer.h> 73 74#ifdef OPENSSL_SYS_VMS 75#include <unixio.h> 76#endif 77#ifndef NO_SYS_TYPES_H 78# include <sys/types.h> 79#endif 80#ifndef OPENSSL_NO_POSIX_IO 81# include <sys/stat.h> 82# include <fcntl.h> 83#endif 84 85#ifdef _WIN32 86#define stat _stat 87#define chmod _chmod 88#define open _open 89#define fdopen _fdopen 90#endif 91 92#undef BUFSIZE 93#define BUFSIZE 1024 94#define RAND_DATA 1024 95 96#ifdef OPENSSL_SYS_VMS 97/* This declaration is a nasty hack to get around vms' extension to fopen 98 * for passing in sharing options being disabled by our /STANDARD=ANSI89 */ 99static FILE *(*const vms_fopen)(const char *, const char *, ...) = 100 (FILE *(*)(const char *, const char *, ...))fopen; 101#define VMS_OPEN_ATTRS "shr=get,put,upd,del","ctx=bin,stm","rfm=stm","rat=none","mrs=0" 102#endif 103 104/* #define RFILE ".rnd" - defined in ../../e_os.h */ 105 106/* Note that these functions are intended for seed files only. 107 * Entropy devices and EGD sockets are handled in rand_unix.c */ 108 109int RAND_load_file(const char *file, long bytes) 110 { 111 /* If bytes >= 0, read up to 'bytes' bytes. 112 * if bytes == -1, read complete file. */ 113 114 MS_STATIC unsigned char buf[BUFSIZE]; 115#ifndef OPENSSL_NO_POSIX_IO 116 struct stat sb; 117#endif 118 int i,ret=0,n; 119 FILE *in; 120 121 if (file == NULL) return(0); 122 123#ifndef OPENSSL_NO_POSIX_IO 124#ifdef PURIFY 125 /* struct stat can have padding and unused fields that may not be 126 * initialized in the call to stat(). We need to clear the entire 127 * structure before calling RAND_add() to avoid complaints from 128 * applications such as Valgrind. 129 */ 130 memset(&sb, 0, sizeof(sb)); 131#endif 132 if (stat(file,&sb) < 0) return(0); 133 RAND_add(&sb,sizeof(sb),0.0); 134#endif 135 if (bytes == 0) return(ret); 136 137#ifdef OPENSSL_SYS_VMS 138 in=vms_fopen(file,"rb",VMS_OPEN_ATTRS); 139#else 140 in=fopen(file,"rb"); 141#endif 142 if (in == NULL) goto err; 143#if defined(S_IFBLK) && defined(S_IFCHR) && !defined(OPENSSL_NO_POSIX_IO) 144 if (sb.st_mode & (S_IFBLK | S_IFCHR)) { 145 /* this file is a device. we don't want read an infinite number 146 * of bytes from a random device, nor do we want to use buffered 147 * I/O because we will waste system entropy. 148 */ 149 bytes = (bytes == -1) ? 2048 : bytes; /* ok, is 2048 enough? */ 150#ifndef OPENSSL_NO_SETVBUF_IONBF 151 setvbuf(in, NULL, _IONBF, 0); /* don't do buffered reads */ 152#endif /* ndef OPENSSL_NO_SETVBUF_IONBF */ 153 } 154#endif 155 for (;;) 156 { 157 if (bytes > 0) 158 n = (bytes < BUFSIZE)?(int)bytes:BUFSIZE; 159 else 160 n = BUFSIZE; 161 i=fread(buf,1,n,in); 162 if (i <= 0) break; 163#ifdef PURIFY 164 RAND_add(buf,i,(double)i); 165#else 166 /* even if n != i, use the full array */ 167 RAND_add(buf,n,(double)i); 168#endif 169 ret+=i; 170 if (bytes > 0) 171 { 172 bytes-=n; 173 if (bytes <= 0) break; 174 } 175 } 176 fclose(in); 177 OPENSSL_cleanse(buf,BUFSIZE); 178err: 179 return(ret); 180 } 181 182int RAND_write_file(const char *file) 183 { 184 unsigned char buf[BUFSIZE]; 185 int i,ret=0,rand_err=0; 186 FILE *out = NULL; 187 int n; 188#ifndef OPENSSL_NO_POSIX_IO 189 struct stat sb; 190 191 i=stat(file,&sb); 192 if (i != -1) { 193#if defined(S_ISBLK) && defined(S_ISCHR) 194 if (S_ISBLK(sb.st_mode) || S_ISCHR(sb.st_mode)) { 195 /* this file is a device. we don't write back to it. 196 * we "succeed" on the assumption this is some sort 197 * of random device. Otherwise attempting to write to 198 * and chmod the device causes problems. 199 */ 200 return(1); 201 } 202#endif 203 } 204#endif 205 206#if defined(O_CREAT) && !defined(OPENSSL_NO_POSIX_IO) && !defined(OPENSSL_SYS_VMS) 207 { 208#ifndef O_BINARY 209#define O_BINARY 0 210#endif 211 /* chmod(..., 0600) is too late to protect the file, 212 * permissions should be restrictive from the start */ 213 int fd = open(file, O_WRONLY|O_CREAT|O_BINARY, 0600); 214 if (fd != -1) 215 out = fdopen(fd, "wb"); 216 } 217#endif 218 219#ifdef OPENSSL_SYS_VMS 220 /* VMS NOTE: Prior versions of this routine created a _new_ 221 * version of the rand file for each call into this routine, then 222 * deleted all existing versions named ;-1, and finally renamed 223 * the current version as ';1'. Under concurrent usage, this 224 * resulted in an RMS race condition in rename() which could 225 * orphan files (see vms message help for RMS$_REENT). With the 226 * fopen() calls below, openssl/VMS now shares the top-level 227 * version of the rand file. Note that there may still be 228 * conditions where the top-level rand file is locked. If so, this 229 * code will then create a new version of the rand file. Without 230 * the delete and rename code, this can result in ascending file 231 * versions that stop at version 32767, and this routine will then 232 * return an error. The remedy for this is to recode the calling 233 * application to avoid concurrent use of the rand file, or 234 * synchronize usage at the application level. Also consider 235 * whether or not you NEED a persistent rand file in a concurrent 236 * use situation. 237 */ 238 239 out = vms_fopen(file,"rb+",VMS_OPEN_ATTRS); 240 if (out == NULL) 241 out = vms_fopen(file,"wb",VMS_OPEN_ATTRS); 242#else 243 if (out == NULL) 244 out = fopen(file,"wb"); 245#endif 246 if (out == NULL) goto err; 247 248#ifndef NO_CHMOD 249 chmod(file,0600); 250#endif 251 n=RAND_DATA; 252 for (;;) 253 { 254 i=(n > BUFSIZE)?BUFSIZE:n; 255 n-=BUFSIZE; 256 if (RAND_bytes(buf,i) <= 0) 257 rand_err=1; 258 i=fwrite(buf,1,i,out); 259 if (i <= 0) 260 { 261 ret=0; 262 break; 263 } 264 ret+=i; 265 if (n <= 0) break; 266 } 267 268 fclose(out); 269 OPENSSL_cleanse(buf,BUFSIZE); 270err: 271 return (rand_err ? -1 : ret); 272 } 273 274const char *RAND_file_name(char *buf, size_t size) 275 { 276 char *s=NULL; 277#ifdef __OpenBSD__ 278 struct stat sb; 279#endif 280 281 if (OPENSSL_issetugid() == 0) 282 s=getenv("RANDFILE"); 283 if (s != NULL && *s && strlen(s) + 1 < size) 284 { 285 if (BUF_strlcpy(buf,s,size) >= size) 286 return NULL; 287 } 288 else 289 { 290 if (OPENSSL_issetugid() == 0) 291 s=getenv("HOME"); 292#ifdef DEFAULT_HOME 293 if (s == NULL) 294 { 295 s = DEFAULT_HOME; 296 } 297#endif 298 if (s && *s && strlen(s)+strlen(RFILE)+2 < size) 299 { 300 BUF_strlcpy(buf,s,size); 301#ifndef OPENSSL_SYS_VMS 302 BUF_strlcat(buf,"/",size); 303#endif 304 BUF_strlcat(buf,RFILE,size); 305 } 306 else 307 buf[0] = '\0'; /* no file name */ 308 } 309 310#ifdef __OpenBSD__ 311 /* given that all random loads just fail if the file can't be 312 * seen on a stat, we stat the file we're returning, if it 313 * fails, use /dev/arandom instead. this allows the user to 314 * use their own source for good random data, but defaults 315 * to something hopefully decent if that isn't available. 316 */ 317 318 if (!buf[0]) 319 if (BUF_strlcpy(buf,"/dev/arandom",size) >= size) { 320 return(NULL); 321 } 322 if (stat(buf,&sb) == -1) 323 if (BUF_strlcpy(buf,"/dev/arandom",size) >= size) { 324 return(NULL); 325 } 326 327#endif 328 return(buf); 329 } 330