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58964a49 | 1 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
d02b48c6 RE |
2 | * All rights reserved. |
3 | * | |
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. | |
0f113f3e | 7 | * |
d02b48c6 RE |
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). | |
0f113f3e | 14 | * |
d02b48c6 RE |
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. | |
0f113f3e | 21 | * |
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22 | * Redistribution and use in source and binary forms, with or without |
23 | * modification, are permitted provided that the following conditions | |
24 | * are met: | |
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 :-). | |
0f113f3e | 36 | * 4. If you include any Windows specific code (or a derivative thereof) from |
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37 | * the apps directory (application code) you must include an acknowledgement: |
38 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" | |
0f113f3e | 39 | * |
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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 | |
50 | * SUCH DAMAGE. | |
0f113f3e | 51 | * |
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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.] | |
56 | */ | |
57 | ||
58 | #include "des_locl.h" | |
59 | ||
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60 | /* |
61 | * The input and output are loaded in multiples of 8 bits. What this means is | |
0d4fb843 | 62 | * that if you have numbits=12 and length=2 the first 12 bits will be |
0f113f3e MC |
63 | * retrieved from the first byte and half the second. The second 12 bits |
64 | * will come from the 3rd and half the 4th byte. | |
d02b48c6 | 65 | */ |
c2e4f17c | 66 | void DES_ofb_encrypt(const unsigned char *in, unsigned char *out, int numbits, |
0f113f3e MC |
67 | long length, DES_key_schedule *schedule, |
68 | DES_cblock *ivec) | |
69 | { | |
70 | register DES_LONG d0, d1, vv0, vv1, v0, v1, n = (numbits + 7) / 8; | |
71 | register DES_LONG mask0, mask1; | |
72 | register long l = length; | |
73 | register int num = numbits; | |
74 | DES_LONG ti[2]; | |
75 | unsigned char *iv; | |
d02b48c6 | 76 | |
0f113f3e MC |
77 | if (num > 64) |
78 | return; | |
79 | if (num > 32) { | |
80 | mask0 = 0xffffffffL; | |
81 | if (num >= 64) | |
82 | mask1 = mask0; | |
83 | else | |
84 | mask1 = (1L << (num - 32)) - 1; | |
85 | } else { | |
86 | if (num == 32) | |
87 | mask0 = 0xffffffffL; | |
88 | else | |
89 | mask0 = (1L << num) - 1; | |
90 | mask1 = 0x00000000L; | |
91 | } | |
d02b48c6 | 92 | |
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93 | iv = &(*ivec)[0]; |
94 | c2l(iv, v0); | |
95 | c2l(iv, v1); | |
96 | ti[0] = v0; | |
97 | ti[1] = v1; | |
98 | while (l-- > 0) { | |
99 | ti[0] = v0; | |
100 | ti[1] = v1; | |
101 | DES_encrypt1((DES_LONG *)ti, schedule, DES_ENCRYPT); | |
102 | vv0 = ti[0]; | |
103 | vv1 = ti[1]; | |
104 | c2ln(in, d0, d1, n); | |
105 | in += n; | |
106 | d0 = (d0 ^ vv0) & mask0; | |
107 | d1 = (d1 ^ vv1) & mask1; | |
108 | l2cn(d0, d1, out, n); | |
109 | out += n; | |
58964a49 | 110 | |
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111 | if (num == 32) { |
112 | v0 = v1; | |
113 | v1 = vv0; | |
114 | } else if (num == 64) { | |
115 | v0 = vv0; | |
116 | v1 = vv1; | |
117 | } else if (num > 32) { /* && num != 64 */ | |
118 | v0 = ((v1 >> (num - 32)) | (vv0 << (64 - num))) & 0xffffffffL; | |
119 | v1 = ((vv0 >> (num - 32)) | (vv1 << (64 - num))) & 0xffffffffL; | |
120 | } else { /* num < 32 */ | |
d02b48c6 | 121 | |
0f113f3e MC |
122 | v0 = ((v0 >> num) | (v1 << (32 - num))) & 0xffffffffL; |
123 | v1 = ((v1 >> num) | (vv0 << (32 - num))) & 0xffffffffL; | |
124 | } | |
125 | } | |
126 | iv = &(*ivec)[0]; | |
127 | l2c(v0, iv); | |
128 | l2c(v1, iv); | |
129 | v0 = v1 = d0 = d1 = ti[0] = ti[1] = vv0 = vv1 = 0; | |
130 | } |