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#ifdef _WIN32 85#define stat _stat 86#define chmod _chmod 87#define open _open 88#define fdopen _fdopen 89#endif 90 91#undef BUFSIZE 92#define BUFSIZE 1024 93#define RAND_DATA 1024 94 95#ifdef OPENSSL_SYS_VMS 96/* This declaration is a nasty hack to get around vms' extension to fopen 97 * for passing in sharing options being disabled by our /STANDARD=ANSI89 */ 98static FILE *(*const vms_fopen)(const char *, const char *, ...) = 99 (FILE *(*)(const char *, const char *, ...))fopen; 100#define VMS_OPEN_ATTRS "shr=get,put,upd,del","ctx=bin,stm","rfm=stm","rat=none","mrs=0" 101#endif 102 103/* #define RFILE ".rnd" - defined in ../../e_os.h */ 104 105/* Note that these functions are intended for seed files only. 106 * Entropy devices and EGD sockets are handled in rand_unix.c */ 107 108int RAND_load_file(const char *file, long bytes) 109 { 110 /* If bytes >= 0, read up to 'bytes' bytes. 111 * if bytes == -1, read complete file. */ 112 113 MS_STATIC unsigned char buf[BUFSIZE]; 114 struct stat sb; 115 int i,ret=0,n; 116 FILE *in; 117 118 if (file == NULL) return(0); 119 120#ifdef PURIFY 121 /* struct stat can have padding and unused fields that may not be 122 * initialized in the call to stat(). We need to clear the entire 123 * structure before calling RAND_add() to avoid complaints from 124 * applications such as Valgrind. 125 */ 126 memset(&sb, 0, sizeof(sb)); 127#endif 128 129 if (stat(file,&sb) < 0) return(0); 130 RAND_add(&sb,sizeof(sb),0.0); 131 if (bytes == 0) return(ret); 132 133#ifdef OPENSSL_SYS_VMS 134 in=vms_fopen(file,"rb",VMS_OPEN_ATTRS); 135#else 136 in=fopen(file,"rb"); 137#endif 138 if (in == NULL) goto err; 139#if defined(S_ISBLK) && defined(S_ISCHR) 140 if (S_ISBLK(sb.st_mode) || S_ISCHR(sb.st_mode)) { 141 /* this file is a device. we don't want read an infinite number 142 * of bytes from a random device, nor do we want to use buffered 143 * I/O because we will waste system entropy. 144 */ 145 bytes = (bytes == -1) ? 2048 : bytes; /* ok, is 2048 enough? */ 146 setvbuf(in, NULL, _IONBF, 0); /* don't do buffered reads */ 147 } 148#endif 149 for (;;) 150 { 151 if (bytes > 0) 152 n = (bytes < BUFSIZE)?(int)bytes:BUFSIZE; 153 else 154 n = BUFSIZE; 155 i=fread(buf,1,n,in); 156 if (i <= 0) break; 157#ifdef PURIFY 158 RAND_add(buf,i,(double)i); 159#else 160 /* even if n != i, use the full array */ 161 RAND_add(buf,n,(double)i); 162#endif 163 ret+=i; 164 if (bytes > 0) 165 { 166 bytes-=n; 167 if (bytes <= 0) break; 168 } 169 } 170 fclose(in); 171 OPENSSL_cleanse(buf,BUFSIZE); 172err: 173 return(ret); 174 } 175 176int RAND_write_file(const char *file) 177 { 178 unsigned char buf[BUFSIZE]; 179 int i,ret=0,rand_err=0; 180 FILE *out = NULL; 181 int n; 182 struct stat sb; 183 184 i=stat(file,&sb); 185 if (i != -1) { 186#if defined(S_ISBLK) && defined(S_ISCHR) 187 if (S_ISBLK(sb.st_mode) || S_ISCHR(sb.st_mode)) { 188 /* this file is a device. we don't write back to it. 189 * we "succeed" on the assumption this is some sort 190 * of random device. Otherwise attempting to write to 191 * and chmod the device causes problems. 192 */ 193 return(1); 194 } 195#endif 196 } 197 198#if defined(O_CREAT) && !defined(OPENSSL_SYS_WIN32) && !defined(OPENSSL_SYS_VMS) 199 { 200 /* For some reason Win32 can't write to files created this way */ 201 202 /* chmod(..., 0600) is too late to protect the file, 203 * permissions should be restrictive from the start */ 204 int fd = open(file, O_CREAT, 0600); 205 if (fd != -1) 206 out = fdopen(fd, "wb"); 207 } 208#endif 209 210#ifdef OPENSSL_SYS_VMS 211 /* VMS NOTE: Prior versions of this routine created a _new_ 212 * version of the rand file for each call into this routine, then 213 * deleted all existing versions named ;-1, and finally renamed 214 * the current version as ';1'. Under concurrent usage, this 215 * resulted in an RMS race condition in rename() which could 216 * orphan files (see vms message help for RMS$_REENT). With the 217 * fopen() calls below, openssl/VMS now shares the top-level 218 * version of the rand file. Note that there may still be 219 * conditions where the top-level rand file is locked. If so, this 220 * code will then create a new version of the rand file. Without 221 * the delete and rename code, this can result in ascending file 222 * versions that stop at version 32767, and this routine will then 223 * return an error. The remedy for this is to recode the calling 224 * application to avoid concurrent use of the rand file, or 225 * synchronize usage at the application level. Also consider 226 * whether or not you NEED a persistent rand file in a concurrent 227 * use situation. 228 */ 229 230 out = vms_fopen(file,"rb+",VMS_OPEN_ATTRS); 231 if (out == NULL) 232 out = vms_fopen(file,"wb",VMS_OPEN_ATTRS); 233#else 234 if (out == NULL) 235 out = fopen(file,"wb"); 236#endif 237 if (out == NULL) goto err; 238 239#ifndef NO_CHMOD 240 chmod(file,0600); 241#endif 242 n=RAND_DATA; 243 for (;;) 244 { 245 i=(n > BUFSIZE)?BUFSIZE:n; 246 n-=BUFSIZE; 247 if (RAND_bytes(buf,i) <= 0) 248 rand_err=1; 249 i=fwrite(buf,1,i,out); 250 if (i <= 0) 251 { 252 ret=0; 253 break; 254 } 255 ret+=i; 256 if (n <= 0) break; 257 } 258 259 fclose(out); 260 OPENSSL_cleanse(buf,BUFSIZE); 261err: 262 return (rand_err ? -1 : ret); 263 } 264 265const char *RAND_file_name(char *buf, size_t size) 266 { 267 char *s=NULL; 268#ifdef __OpenBSD__ 269 int ok = 0; 270 struct stat sb; 271#endif 272 273 if (OPENSSL_issetugid() == 0) 274 s=getenv("RANDFILE"); 275 if (s != NULL && *s && strlen(s) + 1 < size) 276 { 277 if (BUF_strlcpy(buf,s,size) >= size) 278 return NULL; 279 } 280 else 281 { 282 if (OPENSSL_issetugid() == 0) 283 s=getenv("HOME"); 284#ifdef DEFAULT_HOME 285 if (s == NULL) 286 { 287 s = DEFAULT_HOME; 288 } 289#endif 290 if (s && *s && strlen(s)+strlen(RFILE)+2 < size) 291 { 292 BUF_strlcpy(buf,s,size); 293#ifndef OPENSSL_SYS_VMS 294 BUF_strlcat(buf,"/",size); 295#endif 296 BUF_strlcat(buf,RFILE,size); 297#ifdef __OpenBSD__ 298 ok = 1; 299#endif 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 (!ok) 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