Line data Source code
1 : /* crypto/idea/i_cfb64.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 <openssl/idea.h>
60 : #include "idea_lcl.h"
61 :
62 : /*
63 : * The input and output encrypted as though 64bit cfb mode is being used.
64 : * The extra state information to record how much of the 64bit block we have
65 : * used is contained in *num;
66 : */
67 :
68 0 : void idea_cfb64_encrypt(const unsigned char *in, unsigned char *out,
69 : long length, IDEA_KEY_SCHEDULE *schedule,
70 : unsigned char *ivec, int *num, int encrypt)
71 : {
72 : register unsigned long v0, v1, t;
73 0 : register int n = *num;
74 : register long l = length;
75 : unsigned long ti[2];
76 : unsigned char *iv, c, cc;
77 :
78 : iv = (unsigned char *)ivec;
79 0 : if (encrypt) {
80 0 : while (l--) {
81 0 : if (n == 0) {
82 0 : n2l(iv, v0);
83 0 : ti[0] = v0;
84 0 : n2l(iv, v1);
85 0 : ti[1] = v1;
86 0 : idea_encrypt((unsigned long *)ti, schedule);
87 : iv = (unsigned char *)ivec;
88 0 : t = ti[0];
89 0 : l2n(t, iv);
90 0 : t = ti[1];
91 0 : l2n(t, iv);
92 : iv = (unsigned char *)ivec;
93 : }
94 0 : c = *(in++) ^ iv[n];
95 0 : *(out++) = c;
96 0 : iv[n] = c;
97 0 : n = (n + 1) & 0x07;
98 : }
99 : } else {
100 0 : while (l--) {
101 0 : if (n == 0) {
102 0 : n2l(iv, v0);
103 0 : ti[0] = v0;
104 0 : n2l(iv, v1);
105 0 : ti[1] = v1;
106 0 : idea_encrypt((unsigned long *)ti, schedule);
107 : iv = (unsigned char *)ivec;
108 0 : t = ti[0];
109 0 : l2n(t, iv);
110 0 : t = ti[1];
111 0 : l2n(t, iv);
112 : iv = (unsigned char *)ivec;
113 : }
114 0 : cc = *(in++);
115 0 : c = iv[n];
116 0 : iv[n] = cc;
117 0 : *(out++) = c ^ cc;
118 0 : n = (n + 1) & 0x07;
119 : }
120 : }
121 : v0 = v1 = ti[0] = ti[1] = t = c = cc = 0;
122 0 : *num = n;
123 0 : }
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