1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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.
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).
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.
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
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)"
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
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.]
60 #include "internal/cryptlib.h"
63 /* This has some uglies in it but it works - even over sockets. */
67 OPENSSL_IMPLEMENT_GLOBAL(int, DES_rw_mode, DES_PCBC_MODE)
72 * - The data format used by DES_enc_write() and DES_enc_read()
73 * has a cryptographic weakness: When asked to write more
74 * than MAXWRITE bytes, DES_enc_write will split the data
75 * into several chunks that are all encrypted
76 * using the same IV. So don't use these functions unless you
77 * are sure you know what you do (in which case you might
78 * not want to use them anyway).
80 * - This code cannot handle non-blocking sockets.
82 * - This function uses an internal state and thus cannot be
83 * used on multiple files.
85 int DES_enc_read(int fd, void *buf, int len, DES_key_schedule *sched,
88 #if defined(OPENSSL_NO_POSIX_IO)
91 /* data to be unencrypted */
93 static unsigned char *net = NULL;
95 * extra unencrypted data for when a block of 100 comes in but is
96 * des_read one byte at a time.
98 static unsigned char *unnet = NULL;
99 static int unnet_start = 0;
100 static int unnet_left = 0;
101 static unsigned char *tmpbuf = NULL;
106 if (tmpbuf == NULL) {
107 tmpbuf = OPENSSL_malloc(BSIZE);
112 net = OPENSSL_malloc(BSIZE);
117 unnet = OPENSSL_malloc(BSIZE);
121 /* left over data from last decrypt */
122 if (unnet_left != 0) {
123 if (unnet_left < len) {
125 * we still still need more data but will return with the number
126 * of bytes we have - should always check the return value
128 memcpy(buf, &(unnet[unnet_start]), unnet_left);
130 * eay 26/08/92 I had the next 2 lines reversed :-(
133 unnet_start = unnet_left = 0;
135 memcpy(buf, &(unnet[unnet_start]), len);
143 /* We need to get more data. */
147 /* first - get the length */
148 while (net_num < HDRSIZE) {
149 # ifndef OPENSSL_SYS_WIN32
150 i = read(fd, (void *)&(net[net_num]), HDRSIZE - net_num);
152 i = _read(fd, (void *)&(net[net_num]), HDRSIZE - net_num);
155 if ((i == -1) && (errno == EINTR))
163 /* we now have at net_num bytes in net */
168 * num should be rounded up to the next group of eight we make sure that
169 * we have read a multiple of 8 bytes from the net.
171 if ((num > MAXWRITE) || (num < 0)) /* error */
173 rnum = (num < 8) ? 8 : ((num + 7) / 8 * 8);
176 while (net_num < rnum) {
177 # ifndef OPENSSL_SYS_WIN32
178 i = read(fd, (void *)&(net[net_num]), rnum - net_num);
180 i = _read(fd, (void *)&(net[net_num]), rnum - net_num);
183 if ((i == -1) && (errno == EINTR))
191 /* Check if there will be data left over. */
193 if (DES_rw_mode & DES_PCBC_MODE)
194 DES_pcbc_encrypt(net, unnet, num, sched, iv, DES_DECRYPT);
196 DES_cbc_encrypt(net, unnet, num, sched, iv, DES_DECRYPT);
197 memcpy(buf, unnet, len);
199 unnet_left = num - len;
202 * The following line is done because we return num as the number of
208 * >output is a multiple of 8 byes, if len < rnum
209 * >we must be careful. The user must be aware that this
210 * >routine will write more bytes than he asked for.
211 * >The length of the buffer must be correct.
212 * FIXED - Should be ok now 18-9-90 - eay */
215 if (DES_rw_mode & DES_PCBC_MODE)
216 DES_pcbc_encrypt(net, tmpbuf, num, sched, iv, DES_DECRYPT);
218 DES_cbc_encrypt(net, tmpbuf, num, sched, iv, DES_DECRYPT);
221 * eay 26/08/92 fix a bug that returned more bytes than you asked
222 * for (returned len bytes :-(
224 memcpy(buf, tmpbuf, num);
226 if (DES_rw_mode & DES_PCBC_MODE)
227 DES_pcbc_encrypt(net, buf, num, sched, iv, DES_DECRYPT);
229 DES_cbc_encrypt(net, buf, num, sched, iv, DES_DECRYPT);
233 #endif /* OPENSSL_NO_POSIX_IO */