1 /* crypto/des/pcbc_enc.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 "des_locl.h"
60
61 void DES_pcbc_encrypt(const unsigned char *input, unsigned char *output,
62 long length, DES_key_schedule *schedule,
63 DES_cblock *ivec, int enc)
64 {
65 register DES_LONG sin0,sin1,xor0,xor1,tout0,tout1;
66 DES_LONG tin[2];
67 const unsigned char *in;
68 unsigned char *out,*iv;
69
70 in=input;
71 out=output;
72 iv = &(*ivec)[0];
73
74 if (enc)
75 {
76 c2l(iv,xor0);
77 c2l(iv,xor1);
78 for (; length>0; length-=8)
79 {
80 if (length >= 8)
81 {
82 c2l(in,sin0);
83 c2l(in,sin1);
84 }
85 else
86 c2ln(in,sin0,sin1,length);
87 tin[0]=sin0^xor0;
88 tin[1]=sin1^xor1;
89 DES_encrypt1((DES_LONG *)tin,schedule,DES_ENCRYPT);
90 tout0=tin[0];
91 tout1=tin[1];
92 xor0=sin0^tout0;
93 xor1=sin1^tout1;
94 l2c(tout0,out);
95 l2c(tout1,out);
96 }
97 }
98 else
99 {
100 c2l(iv,xor0); c2l(iv,xor1);
101 for (; length>0; length-=8)
102 {
103 c2l(in,sin0);
104 c2l(in,sin1);
105 tin[0]=sin0;
106 tin[1]=sin1;
107 DES_encrypt1((DES_LONG *)tin,schedule,DES_DECRYPT);
108 tout0=tin[0]^xor0;
109 tout1=tin[1]^xor1;
110 if (length >= 8)
111 {
112 l2c(tout0,out);
113 l2c(tout1,out);
114 }
115 else
116 l2cn(tout0,tout1,out,length);
117 xor0=tout0^sin0;
118 xor1=tout1^sin1;
119 }
120 }
121 tin[0]=tin[1]=0;
122 sin0=sin1=xor0=xor1=tout0=tout1=0;
123 }