]>
Commit | Line | Data |
---|---|---|
d02b48c6 | 1 | /* crypto/des/cfb_enc.c */ |
58964a49 | 2 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
d02b48c6 RE |
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 are loaded in multiples of 8 bits. | |
62 | * What this means is that if you hame numbits=12 and length=2 | |
63 | * the first 12 bits will be retrieved from the first byte and half | |
64 | * the second. The second 12 bits will come from the 3rd and half the 4th | |
65 | * byte. | |
66 | */ | |
6b691a5c | 67 | void des_cfb_encrypt(const unsigned char *in, unsigned char *out, int numbits, |
3ba5d1cf | 68 | long length, des_key_schedule *schedule, des_cblock *ivec, int enc) |
d02b48c6 RE |
69 | { |
70 | register DES_LONG d0,d1,v0,v1,n=(numbits+7)/8; | |
71 | register DES_LONG mask0,mask1; | |
72 | register unsigned long l=length; | |
73 | register int num=numbits; | |
74 | DES_LONG ti[2]; | |
75 | unsigned char *iv; | |
76 | ||
77 | if (num > 64) return; | |
78 | if (num > 32) | |
79 | { | |
80 | mask0=0xffffffffL; | |
81 | if (num == 64) | |
82 | mask1=mask0; | |
83 | else mask1=(1L<<(num-32))-1; | |
84 | } | |
85 | else | |
86 | { | |
87 | if (num == 32) | |
88 | mask0=0xffffffffL; | |
89 | else mask0=(1L<<num)-1; | |
58964a49 | 90 | mask1=0x00000000L; |
d02b48c6 RE |
91 | } |
92 | ||
edf0bfb5 | 93 | iv = &(*ivec)[0]; |
d02b48c6 RE |
94 | c2l(iv,v0); |
95 | c2l(iv,v1); | |
96 | if (enc) | |
97 | { | |
98 | while (l >= n) | |
99 | { | |
100 | l-=n; | |
101 | ti[0]=v0; | |
102 | ti[1]=v1; | |
080b8cad | 103 | des_encrypt1((DES_LONG *)ti,schedule,DES_ENCRYPT); |
d02b48c6 RE |
104 | c2ln(in,d0,d1,n); |
105 | in+=n; | |
106 | d0=(d0^ti[0])&mask0; | |
107 | d1=(d1^ti[1])&mask1; | |
108 | l2cn(d0,d1,out,n); | |
109 | out+=n; | |
110 | /* 30-08-94 - eay - changed because l>>32 and | |
111 | * l<<32 are bad under gcc :-( */ | |
112 | if (num == 32) | |
113 | { v0=v1; v1=d0; } | |
114 | else if (num == 64) | |
115 | { v0=d0; v1=d1; } | |
116 | else if (num > 32) /* && num != 64 */ | |
117 | { | |
118 | v0=((v1>>(num-32))|(d0<<(64-num)))&0xffffffffL; | |
119 | v1=((d0>>(num-32))|(d1<<(64-num)))&0xffffffffL; | |
120 | } | |
121 | else /* num < 32 */ | |
122 | { | |
123 | v0=((v0>>num)|(v1<<(32-num)))&0xffffffffL; | |
124 | v1=((v1>>num)|(d0<<(32-num)))&0xffffffffL; | |
125 | } | |
126 | } | |
127 | } | |
128 | else | |
129 | { | |
130 | while (l >= n) | |
131 | { | |
132 | l-=n; | |
133 | ti[0]=v0; | |
134 | ti[1]=v1; | |
080b8cad | 135 | des_encrypt1((DES_LONG *)ti,schedule,DES_ENCRYPT); |
d02b48c6 RE |
136 | c2ln(in,d0,d1,n); |
137 | in+=n; | |
138 | /* 30-08-94 - eay - changed because l>>32 and | |
139 | * l<<32 are bad under gcc :-( */ | |
140 | if (num == 32) | |
141 | { v0=v1; v1=d0; } | |
142 | else if (num == 64) | |
143 | { v0=d0; v1=d1; } | |
144 | else if (num > 32) /* && num != 64 */ | |
145 | { | |
146 | v0=((v1>>(num-32))|(d0<<(64-num)))&0xffffffffL; | |
147 | v1=((d0>>(num-32))|(d1<<(64-num)))&0xffffffffL; | |
148 | } | |
149 | else /* num < 32 */ | |
150 | { | |
151 | v0=((v0>>num)|(v1<<(32-num)))&0xffffffffL; | |
152 | v1=((v1>>num)|(d0<<(32-num)))&0xffffffffL; | |
153 | } | |
154 | d0=(d0^ti[0])&mask0; | |
155 | d1=(d1^ti[1])&mask1; | |
156 | l2cn(d0,d1,out,n); | |
157 | out+=n; | |
158 | } | |
159 | } | |
edf0bfb5 | 160 | iv = &(*ivec)[0]; |
d02b48c6 RE |
161 | l2c(v0,iv); |
162 | l2c(v1,iv); | |
163 | v0=v1=d0=d1=ti[0]=ti[1]=0; | |
164 | } | |
165 |