Branch data Line data Source code
1 : : /* crypto/des/cfb64enc.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 : : /* The input and output encrypted as though 64bit cfb mode is being
62 : : * used. The extra state information to record how much of the
63 : : * 64bit block we have used is contained in *num;
64 : : */
65 : :
66 : 36 : void DES_cfb64_encrypt(const unsigned char *in, unsigned char *out,
67 : : long length, DES_key_schedule *schedule,
68 : : DES_cblock *ivec, int *num, int enc)
69 : : {
70 : : register DES_LONG v0,v1;
71 : 36 : register long l=length;
72 : 36 : register int n= *num;
73 : : DES_LONG ti[2];
74 : : unsigned char *iv,c,cc;
75 : :
76 : 36 : iv = &(*ivec)[0];
77 [ + + ]: 36 : if (enc)
78 : : {
79 [ + + ]: 2076 : while (l--)
80 : : {
81 [ + + ]: 2056 : if (n == 0)
82 : : {
83 : 257 : c2l(iv,v0); ti[0]=v0;
84 : 257 : c2l(iv,v1); ti[1]=v1;
85 : 257 : DES_encrypt1(ti,schedule,DES_ENCRYPT);
86 : 257 : iv = &(*ivec)[0];
87 : 257 : v0=ti[0]; l2c(v0,iv);
88 : 257 : v0=ti[1]; l2c(v0,iv);
89 : 257 : iv = &(*ivec)[0];
90 : : }
91 : 2056 : c= *(in++)^iv[n];
92 : 2056 : *(out++)=c;
93 : 2056 : iv[n]=c;
94 : 2056 : n=(n+1)&0x07;
95 : : }
96 : : }
97 : : else
98 : : {
99 [ + + ]: 2072 : while (l--)
100 : : {
101 [ + + ]: 2056 : if (n == 0)
102 : : {
103 : 257 : c2l(iv,v0); ti[0]=v0;
104 : 257 : c2l(iv,v1); ti[1]=v1;
105 : 257 : DES_encrypt1(ti,schedule,DES_ENCRYPT);
106 : 257 : iv = &(*ivec)[0];
107 : 257 : v0=ti[0]; l2c(v0,iv);
108 : 257 : v0=ti[1]; l2c(v0,iv);
109 : 257 : iv = &(*ivec)[0];
110 : : }
111 : 2056 : cc= *(in++);
112 : 2056 : c=iv[n];
113 : 2056 : iv[n]=cc;
114 : 2056 : *(out++)=c^cc;
115 : 2056 : n=(n+1)&0x07;
116 : : }
117 : : }
118 : 36 : v0=v1=ti[0]=ti[1]=c=cc=0;
119 : 36 : *num=n;
120 : 36 : }
121 : :
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