crypto/des/enc_writ.c

   1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   2  * All rights reserved.
   3  *
   4  * This package is an SSL implementation written
   5  * by Eric Young (eay@cryptsoft.com).
   6  * The implementation was written so as to conform with Netscapes SSL.
   7  *
   8  * This library is free for commercial and non-commercial use as long as
   9  * the following conditions are aheared to.  The following conditions
  10  * apply to all code found in this distribution, be it the RC4, RSA,
  11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  12  * included with this distribution is covered by the same copyright terms
  13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  14  *
  15  * Copyright remains Eric Young's, and as such any Copyright notices in
  16  * the code are not to be removed.
  17  * If this package is used in a product, Eric Young should be given attribution
  18  * as the author of the parts of the library used.
  19  * This can be in the form of a textual message at program startup or
  20  * in documentation (online or textual) provided with the package.
  21  *
  22  * Redistribution and use in source and binary forms, with or without
  23  * modification, are permitted provided that the following conditions
  24  * are met:
  25  * 1. Redistributions of source code must retain the copyright
  26  *    notice, this list of conditions and the following disclaimer.
  27  * 2. Redistributions in binary form must reproduce the above copyright
  28  *    notice, this list of conditions and the following disclaimer in the
  29  *    documentation and/or other materials provided with the distribution.
  30  * 3. All advertising materials mentioning features or use of this software
  31  *    must display the following acknowledgement:
  32  *    "This product includes cryptographic software written by
  33  *     Eric Young (eay@cryptsoft.com)"
  34  *    The word 'cryptographic' can be left out if the rouines from the library
  35  *    being used are not cryptographic related :-).
  36  * 4. If you include any Windows specific code (or a derivative thereof) from
  37  *    the apps directory (application code) you must include an acknowledgement:
  38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  50  * SUCH DAMAGE.
  51  *
  52  * The licence and distribution terms for any publically available version or
  53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  54  * copied and put under another distribution licence
  55  * [including the GNU Public Licence.]
  56  */
  57
  58 #include <errno.h>
  59 #include <time.h>
  60 #include <stdio.h>
  61 #include "internal/cryptlib.h"
  62 #include "des_locl.h"
  63 #include <openssl/rand.h>
  64
  65 /*-
  66  * WARNINGS:
  67  *
  68  *  -  The data format used by DES_enc_write() and DES_enc_read()
  69  *     has a cryptographic weakness: When asked to write more
  70  *     than MAXWRITE bytes, DES_enc_write will split the data
  71  *     into several chunks that are all encrypted
  72  *     using the same IV.  So don't use these functions unless you
  73  *     are sure you know what you do (in which case you might
  74  *     not want to use them anyway).
  75  *
  76  *  -  This code cannot handle non-blocking sockets.
  77  */
  78
  79 int DES_enc_write(int fd, const void *_buf, int len,
  80                   DES_key_schedule *sched, DES_cblock *iv)
  81 {
  82 #if defined(OPENSSL_NO_POSIX_IO)
  83     return (-1);
  84 #else
  85 # ifdef _LIBC
  86     extern unsigned long time();
  87     extern int write();
  88 # endif
  89     const unsigned char *buf = _buf;
  90     long rnum;
  91     int i, j, k, outnum;
  92     static unsigned char *outbuf = NULL;
  93     unsigned char shortbuf[8];
  94     unsigned char *p;
  95     const unsigned char *cp;
  96     static int start = 1;
  97
  98     if (len < 0)
  99         return -1;
 100
 101     if (outbuf == NULL) {
 102         outbuf = OPENSSL_malloc(BSIZE + HDRSIZE);
 103         if (outbuf == NULL)
 104             return (-1);
 105     }
 106     /*
 107      * If we are sending less than 8 bytes, the same char will look the same
 108      * if we don't pad it out with random bytes
 109      */
 110     if (start) {
 111         start = 0;
 112     }
 113
 114     /* lets recurse if we want to send the data in small chunks */
 115     if (len > MAXWRITE) {
 116         j = 0;
 117         for (i = 0; i < len; i += k) {
 118             k = DES_enc_write(fd, &(buf[i]),
 119                               ((len - i) > MAXWRITE) ? MAXWRITE : (len - i),
 120                               sched, iv);
 121             if (k < 0)
 122                 return (k);
 123             else
 124                 j += k;
 125         }
 126         return (j);
 127     }
 128
 129     /* write length first */
 130     p = outbuf;
 131     l2n(len, p);
 132
 133     /* pad short strings */
 134     if (len < 8) {
 135         cp = shortbuf;
 136         memcpy(shortbuf, buf, len);
 137         if (RAND_bytes(shortbuf + len, 8 - len) <= 0)
 138             return -1;
 139         rnum = 8;
 140     } else {
 141         cp = buf;
 142         rnum = ((len + 7) / 8 * 8); /* round up to nearest eight */
 143     }
 144
 145     if (DES_rw_mode & DES_PCBC_MODE)
 146         DES_pcbc_encrypt(cp, &(outbuf[HDRSIZE]), (len < 8) ? 8 : len, sched,
 147                          iv, DES_ENCRYPT);
 148     else
 149         DES_cbc_encrypt(cp, &(outbuf[HDRSIZE]), (len < 8) ? 8 : len, sched,
 150                         iv, DES_ENCRYPT);
 151
 152     /* output */
 153     outnum = rnum + HDRSIZE;
 154
 155     for (j = 0; j < outnum; j += i) {
 156         /*
 157          * eay 26/08/92 I was not doing writing from where we got up to.
 158          */
 159 # ifndef _WIN32
 160         i = write(fd, (void *)&(outbuf[j]), outnum - j);
 161 # else
 162         i = _write(fd, (void *)&(outbuf[j]), outnum - j);
 163 # endif
 164         if (i == -1) {
 165 # ifdef EINTR
 166             if (errno == EINTR)
 167                 i = 0;
 168             else
 169 # endif
 170                 /*
 171                  * This is really a bad error - very bad It will stuff-up
 172                  * both ends.
 173                  */
 174                 return (-1);
 175         }
 176     }
 177
 178     return (len);
 179 #endif                          /* OPENSSL_NO_POSIX_IO */
 180 }