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 #include <errno.h>
  60 #include <stdio.h>
  61 #include <stdlib.h>
  62 #include <string.h>
  63
  64 #ifdef OPENSSL_SYS_VMS
  65 #include <unixio.h>
  66 #endif
  67 #ifndef NO_SYS_TYPES_H
  68 # include <sys/types.h>
  69 #endif
  70 #ifdef MAC_OS_pre_X
  71 # include <stat.h>
  72 #else
  73 # include <sys/stat.h>
  74 #endif
  75
  76 #include <openssl/e_os.h>
  77 #include <openssl/crypto.h>
  78 #include <openssl/rand.h>
  79
  80 #undef BUFSIZE
  81 #define BUFSIZE 1024
  82 #define RAND_DATA 1024
  83
  84 /* #define RFILE ".rnd" - defined in ../../e_os.h */
  85
  86 /* Note that these functions are intended for seed files only.
  87  * Entropy devices and EGD sockets are handled in rand_unix.c */
  88
  89 int RAND_load_file(const char *file, long bytes)
  90         {
  91         /* If bytes >= 0, read up to 'bytes' bytes.
  92          * if bytes == -1, read complete file. */
  93
  94         MS_STATIC unsigned char buf[BUFSIZE];
  95         struct stat sb;
  96         int i,ret=0,n;
  97         FILE *in;
  98
  99         if (file == NULL) return(0);
 100
 101         i=stat(file,&sb);
 102         /* If the state fails, put some crap in anyway */
 103         RAND_add(&sb,sizeof(sb),0);
 104         if (i < 0) return(0);
 105         if (bytes == 0) return(ret);
 106
 107         in=fopen(file,"rb");
 108         if (in == NULL) goto err;
 109         for (;;)
 110                 {
 111                 if (bytes > 0)
 112                         n = (bytes < BUFSIZE)?(int)bytes:BUFSIZE;
 113                 else
 114                         n = BUFSIZE;
 115                 i=fread(buf,1,n,in);
 116                 if (i <= 0) break;
 117                 /* even if n != i, use the full array */
 118                 RAND_add(buf,n,i);
 119                 ret+=i;
 120                 if (bytes > 0)
 121                         {
 122                         bytes-=n;
 123                         if (bytes <= 0) break;
 124                         }
 125                 }
 126         fclose(in);
 127         memset(buf,0,BUFSIZE);
 128 err:
 129         return(ret);
 130         }
 131
 132 int RAND_write_file(const char *file)
 133         {
 134         unsigned char buf[BUFSIZE];
 135         int i,ret=0,rand_err=0;
 136         FILE *out = NULL;
 137         int n;
 138
 139 #if defined(O_CREAT) && !defined(OPENSSL_SYS_WIN32)
 140         /* For some reason Win32 can't write to files created this way */
 141
 142         /* chmod(..., 0600) is too late to protect the file,
 143          * permissions should be restrictive from the start */
 144         int fd = open(file, O_CREAT, 0600);
 145         if (fd != -1)
 146                 out = fdopen(fd, "wb");
 147 #endif
 148         if (out == NULL)
 149                 out = fopen(file,"wb");
 150         if (out == NULL) goto err;
 151
 152 #ifndef NO_CHMOD
 153         chmod(file,0600);
 154 #endif
 155         n=RAND_DATA;
 156         for (;;)
 157                 {
 158                 i=(n > BUFSIZE)?BUFSIZE:n;
 159                 n-=BUFSIZE;
 160                 if (RAND_bytes(buf,i) <= 0)
 161                         rand_err=1;
 162                 i=fwrite(buf,1,i,out);
 163                 if (i <= 0)
 164                         {
 165                         ret=0;
 166                         break;
 167                         }
 168                 ret+=i;
 169                 if (n <= 0) break;
 170                 }
 171 #ifdef OPENSSL_SYS_VMS
 172         /* Try to delete older versions of the file, until there aren't
 173            any */
 174         {
 175         char *tmpf;
 176
 177         tmpf = OPENSSL_malloc(strlen(file) + 4);  /* to add ";-1" and a nul */
 178         if (tmpf)
 179                 {
 180                 strcpy(tmpf, file);
 181                 strcat(tmpf, ";-1");
 182                 while(delete(tmpf) == 0)
 183                         ;
 184                 rename(file,";1"); /* Make sure it's version 1, or we
 185                                       will reach the limit (32767) at
 186                                       some point... */
 187                 }
 188         }
 189 #endif /* OPENSSL_SYS_VMS */
 190
 191         fclose(out);
 192         memset(buf,0,BUFSIZE);
 193 err:
 194         return (rand_err ? -1 : ret);
 195         }
 196
 197 const char *RAND_file_name(char *buf, int size)
 198         {
 199         char *s=NULL;
 200         char *ret=NULL;
 201
 202         if (OPENSSL_issetugid() == 0)
 203                 s=getenv("RANDFILE");
 204         if (s != NULL)
 205                 {
 206                 strncpy(buf,s,size-1);
 207                 buf[size-1]='\0';
 208                 ret=buf;
 209                 }
 210         else
 211                 {
 212                 if (OPENSSL_issetugid() == 0)
 213                         s=getenv("HOME");
 214                 if (s != NULL && (strlen(s)+strlen(RFILE)+2 < size))
 215                         {
 216                         strcpy(buf,s);
 217 #ifndef OPENSSL_SYS_VMS
 218                         strcat(buf,"/");
 219 #endif
 220                         strcat(buf,RFILE);
 221                         ret=buf;
 222                         }
 223                   else
 224                         buf[0] = '\0'; /* no file name */
 225                 }
 226         return(ret);
 227         }