release/src/router/openssl/crypto/rand/randfile.c

   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 */
  96 static 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
 106 int 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(OPENSSL_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 #ifndef OPENSSL_NO_SETVBUF_IONBF
 148           setvbuf(in, NULL, _IONBF, 0); /* don't do buffered reads */
 149 #endif /* ndef OPENSSL_NO_SETVBUF_IONBF */
 150         }
 151 #endif
 152         for (;;)
 153                 {
 154                 if (bytes > 0)
 155                         n = (bytes < BUFSIZE)?(int)bytes:BUFSIZE;
 156                 else
 157                         n = BUFSIZE;
 158                 i=fread(buf,1,n,in);
 159                 if (i <= 0) break;
 160 #ifdef PURIFY
 161                 RAND_add(buf,i,(double)i);
 162 #else
 163                 /* even if n != i, use the full array */
 164                 RAND_add(buf,n,(double)i);
 165 #endif
 166                 ret+=i;
 167                 if (bytes > 0)
 168                         {
 169                         bytes-=n;
 170                         if (bytes <= 0) break;
 171                         }
 172                 }
 173         fclose(in);
 174         OPENSSL_cleanse(buf,BUFSIZE);
 175 err:
 176         return(ret);
 177         }
 178
 179 int RAND_write_file(const char *file)
 180         {
 181         unsigned char buf[BUFSIZE];
 182         int i,ret=0,rand_err=0;
 183         FILE *out = NULL;
 184         int n;
 185 #ifndef OPENSSL_NO_POSIX_IO
 186         struct stat sb;
 187
 188         i=stat(file,&sb);
 189         if (i != -1) {
 190 #if defined(S_ISBLK) && defined(S_ISCHR)
 191           if (S_ISBLK(sb.st_mode) || S_ISCHR(sb.st_mode)) {
 192             /* this file is a device. we don't write back to it.
 193              * we "succeed" on the assumption this is some sort
 194              * of random device. Otherwise attempting to write to
 195              * and chmod the device causes problems.
 196              */
 197             return(1);
 198           }
 199 #endif
 200         }
 201 #endif
 202
 203 #if defined(O_CREAT) && !defined(OPENSSL_NO_POSIX_IO) && !defined(OPENSSL_SYS_VMS)
 204         {
 205 #ifndef O_BINARY
 206 #define O_BINARY 0
 207 #endif
 208         /* chmod(..., 0600) is too late to protect the file,
 209          * permissions should be restrictive from the start */
 210         int fd = open(file, O_WRONLY|O_CREAT|O_BINARY, 0600);
 211         if (fd != -1)
 212                 out = fdopen(fd, "wb");
 213         }
 214 #endif
 215
 216 #ifdef OPENSSL_SYS_VMS
 217         /* VMS NOTE: Prior versions of this routine created a _new_
 218          * version of the rand file for each call into this routine, then
 219          * deleted all existing versions named ;-1, and finally renamed
 220          * the current version as ';1'. Under concurrent usage, this
 221          * resulted in an RMS race condition in rename() which could
 222          * orphan files (see vms message help for RMS$_REENT). With the
 223          * fopen() calls below, openssl/VMS now shares the top-level
 224          * version of the rand file. Note that there may still be
 225          * conditions where the top-level rand file is locked. If so, this
 226          * code will then create a new version of the rand file. Without
 227          * the delete and rename code, this can result in ascending file
 228          * versions that stop at version 32767, and this routine will then
 229          * return an error. The remedy for this is to recode the calling
 230          * application to avoid concurrent use of the rand file, or
 231          * synchronize usage at the application level. Also consider
 232          * whether or not you NEED a persistent rand file in a concurrent
 233          * use situation.
 234          */
 235
 236         out = vms_fopen(file,"rb+",VMS_OPEN_ATTRS);
 237         if (out == NULL)
 238                 out = vms_fopen(file,"wb",VMS_OPEN_ATTRS);
 239 #else
 240         if (out == NULL)
 241                 out = fopen(file,"wb");
 242 #endif
 243         if (out == NULL) goto err;
 244
 245 #ifndef NO_CHMOD
 246         chmod(file,0600);
 247 #endif
 248         n=RAND_DATA;
 249         for (;;)
 250                 {
 251                 i=(n > BUFSIZE)?BUFSIZE:n;
 252                 n-=BUFSIZE;
 253                 if (RAND_bytes(buf,i) <= 0)
 254                         rand_err=1;
 255                 i=fwrite(buf,1,i,out);
 256                 if (i <= 0)
 257                         {
 258                         ret=0;
 259                         break;
 260                         }
 261                 ret+=i;
 262                 if (n <= 0) break;
 263                 }
 264
 265         fclose(out);
 266         OPENSSL_cleanse(buf,BUFSIZE);
 267 err:
 268         return (rand_err ? -1 : ret);
 269         }
 270
 271 const char *RAND_file_name(char *buf, size_t size)
 272         {
 273         char *s=NULL;
 274 #ifdef __OpenBSD__
 275         struct stat sb;
 276 #endif
 277
 278         if (OPENSSL_issetugid() == 0)
 279                 s=getenv("RANDFILE");
 280         if (s != NULL && *s && strlen(s) + 1 < size)
 281                 {
 282                 if (BUF_strlcpy(buf,s,size) >= size)
 283                         return NULL;
 284                 }
 285         else
 286                 {
 287                 if (OPENSSL_issetugid() == 0)
 288                         s=getenv("HOME");
 289 #ifdef DEFAULT_HOME
 290                 if (s == NULL)
 291                         {
 292                         s = DEFAULT_HOME;
 293                         }
 294 #endif
 295                 if (s && *s && strlen(s)+strlen(RFILE)+2 < size)
 296                         {
 297                         BUF_strlcpy(buf,s,size);
 298 #ifndef OPENSSL_SYS_VMS
 299                         BUF_strlcat(buf,"/",size);
 300 #endif
 301                         BUF_strlcat(buf,RFILE,size);
 302                         }
 303                 else
 304                         buf[0] = '\0'; /* no file name */
 305                 }
 306
 307 #ifdef __OpenBSD__
 308         /* given that all random loads just fail if the file can't be
 309          * seen on a stat, we stat the file we're returning, if it
 310          * fails, use /dev/arandom instead. this allows the user to
 311          * use their own source for good random data, but defaults
 312          * to something hopefully decent if that isn't available.
 313          */
 314
 315         if (!buf[0])
 316                 if (BUF_strlcpy(buf,"/dev/arandom",size) >= size) {
 317                         return(NULL);
 318                 }
 319         if (stat(buf,&sb) == -1)
 320                 if (BUF_strlcpy(buf,"/dev/arandom",size) >= size) {
 321                         return(NULL);
 322                 }
 323
 324 #endif
 325         return(buf);
 326         }