enc_writ.c revision 296465 
1/* crypto/des/enc_writ.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 <time.h>
61#include <stdio.h>
62#include "cryptlib.h"
63#include "des_locl.h"
64#include <openssl/rand.h>
65
66/*-
67 * WARNINGS:
68 *
69 *  -  The data format used by DES_enc_write() and DES_enc_read()
70 *     has a cryptographic weakness: When asked to write more
71 *     than MAXWRITE bytes, DES_enc_write will split the data
72 *     into several chunks that are all encrypted
73 *     using the same IV.  So don't use these functions unless you
74 *     are sure you know what you do (in which case you might
75 *     not want to use them anyway).
76 *
77 *  -  This code cannot handle non-blocking sockets.
78 */
79
80int DES_enc_write(int fd, const void *_buf, int len,
81                  DES_key_schedule *sched, DES_cblock *iv)
82{
83#ifdef _LIBC
84    extern unsigned long time();
85    extern int write();
86#endif
87    const unsigned char *buf = _buf;
88    long rnum;
89    int i, j, k, outnum;
90    static unsigned char *outbuf = NULL;
91    unsigned char shortbuf[8];
92    unsigned char *p;
93    const unsigned char *cp;
94    static int start = 1;
95
96    if (outbuf == NULL) {
97        outbuf = OPENSSL_malloc(BSIZE + HDRSIZE);
98        if (outbuf == NULL)
99            return (-1);
100    }
101    /*
102     * If we are sending less than 8 bytes, the same char will look the same
103     * if we don't pad it out with random bytes
104     */
105    if (start) {
106        start = 0;
107    }
108
109    /* lets recurse if we want to send the data in small chunks */
110    if (len > MAXWRITE) {
111        j = 0;
112        for (i = 0; i < len; i += k) {
113            k = DES_enc_write(fd, &(buf[i]),
114                              ((len - i) > MAXWRITE) ? MAXWRITE : (len - i),
115                              sched, iv);
116            if (k < 0)
117                return (k);
118            else
119                j += k;
120        }
121        return (j);
122    }
123
124    /* write length first */
125    p = outbuf;
126    l2n(len, p);
127
128    /* pad short strings */
129    if (len < 8) {
130        cp = shortbuf;
131        memcpy(shortbuf, buf, len);
132        RAND_pseudo_bytes(shortbuf + len, 8 - len);
133        rnum = 8;
134    } else {
135        cp = buf;
136        rnum = ((len + 7) / 8 * 8); /* round up to nearest eight */
137    }
138
139    if (DES_rw_mode & DES_PCBC_MODE)
140        DES_pcbc_encrypt(cp, &(outbuf[HDRSIZE]), (len < 8) ? 8 : len, sched,
141                         iv, DES_ENCRYPT);
142    else
143        DES_cbc_encrypt(cp, &(outbuf[HDRSIZE]), (len < 8) ? 8 : len, sched,
144                        iv, DES_ENCRYPT);
145
146    /* output */
147    outnum = rnum + HDRSIZE;
148
149    for (j = 0; j < outnum; j += i) {
150        /*
151         * eay 26/08/92 I was not doing writing from where we got up to.
152         */
153#ifndef _WIN32
154        i = write(fd, (void *)&(outbuf[j]), outnum - j);
155#else
156        i = _write(fd, (void *)&(outbuf[j]), outnum - j);
157#endif
158        if (i == -1) {
159#ifdef EINTR
160            if (errno == EINTR)
161                i = 0;
162            else
163#endif
164                /*
165                 * This is really a bad error - very bad It will stuff-up
166                 * both ends.
167                 */
168                return (-1);
169        }
170    }
171
172    return (len);
173}
174