]>
git.ipfire.org Git - thirdparty/openssl.git/blob - crypto/des/enc_read.c
1 /* crypto/des/enc_read.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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.
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).
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.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
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)"
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
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.]
64 /* This has some uglies in it but it works - even over sockets. */
68 OPENSSL_IMPLEMENT_GLOBAL(int, DES_rw_mode
, DES_PCBC_MODE
)
73 * - The data format used by DES_enc_write() and DES_enc_read()
74 * has a cryptographic weakness: When asked to write more
75 * than MAXWRITE bytes, DES_enc_write will split the data
76 * into several chunks that are all encrypted
77 * using the same IV. So don't use these functions unless you
78 * are sure you know what you do (in which case you might
79 * not want to use them anyway).
81 * - This code cannot handle non-blocking sockets.
83 * - This function uses an internal state and thus cannot be
84 * used on multiple files.
86 int DES_enc_read(int fd
, void *buf
, int len
, DES_key_schedule
*sched
,
89 #if defined(OPENSSL_NO_POSIX_IO)
92 /* data to be unencrypted */
94 static unsigned char *net
= NULL
;
96 * extra unencrypted data for when a block of 100 comes in but is
97 * des_read one byte at a time.
99 static unsigned char *unnet
= NULL
;
100 static int unnet_start
= 0;
101 static int unnet_left
= 0;
102 static unsigned char *tmpbuf
= NULL
;
107 if (tmpbuf
== NULL
) {
108 tmpbuf
= OPENSSL_malloc(BSIZE
);
113 net
= OPENSSL_malloc(BSIZE
);
118 unnet
= OPENSSL_malloc(BSIZE
);
122 /* left over data from last decrypt */
123 if (unnet_left
!= 0) {
124 if (unnet_left
< len
) {
126 * we still still need more data but will return with the number
127 * of bytes we have - should always check the return value
129 memcpy(buf
, &(unnet
[unnet_start
]), unnet_left
);
131 * eay 26/08/92 I had the next 2 lines reversed :-(
134 unnet_start
= unnet_left
= 0;
136 memcpy(buf
, &(unnet
[unnet_start
]), len
);
144 /* We need to get more data. */
148 /* first - get the length */
149 while (net_num
< HDRSIZE
) {
150 # ifndef OPENSSL_SYS_WIN32
151 i
= read(fd
, (void *)&(net
[net_num
]), HDRSIZE
- net_num
);
153 i
= _read(fd
, (void *)&(net
[net_num
]), HDRSIZE
- net_num
);
156 if ((i
== -1) && (errno
== EINTR
))
164 /* we now have at net_num bytes in net */
169 * num should be rounded up to the next group of eight we make sure that
170 * we have read a multiple of 8 bytes from the net.
172 if ((num
> MAXWRITE
) || (num
< 0)) /* error */
174 rnum
= (num
< 8) ? 8 : ((num
+ 7) / 8 * 8);
177 while (net_num
< rnum
) {
178 # ifndef OPENSSL_SYS_WIN32
179 i
= read(fd
, (void *)&(net
[net_num
]), rnum
- net_num
);
181 i
= _read(fd
, (void *)&(net
[net_num
]), rnum
- net_num
);
184 if ((i
== -1) && (errno
== EINTR
))
192 /* Check if there will be data left over. */
194 if (DES_rw_mode
& DES_PCBC_MODE
)
195 DES_pcbc_encrypt(net
, unnet
, num
, sched
, iv
, DES_DECRYPT
);
197 DES_cbc_encrypt(net
, unnet
, num
, sched
, iv
, DES_DECRYPT
);
198 memcpy(buf
, unnet
, len
);
200 unnet_left
= num
- len
;
203 * The following line is done because we return num as the number of
209 * >output is a multiple of 8 byes, if len < rnum
210 * >we must be careful. The user must be aware that this
211 * >routine will write more bytes than he asked for.
212 * >The length of the buffer must be correct.
213 * FIXED - Should be ok now 18-9-90 - eay */
216 if (DES_rw_mode
& DES_PCBC_MODE
)
217 DES_pcbc_encrypt(net
, tmpbuf
, num
, sched
, iv
, DES_DECRYPT
);
219 DES_cbc_encrypt(net
, tmpbuf
, num
, sched
, iv
, DES_DECRYPT
);
222 * eay 26/08/92 fix a bug that returned more bytes than you asked
223 * for (returned len bytes :-(
225 memcpy(buf
, tmpbuf
, num
);
227 if (DES_rw_mode
& DES_PCBC_MODE
)
228 DES_pcbc_encrypt(net
, buf
, num
, sched
, iv
, DES_DECRYPT
);
230 DES_cbc_encrypt(net
, buf
, num
, sched
, iv
, DES_DECRYPT
);
234 #endif /* OPENSSL_NO_POSIX_IO */