Branch data Line data Source code
1 : : /* crypto/des/ofb_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 : : /* 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 : : */
67 : 2 : void DES_ofb_encrypt(const unsigned char *in, unsigned char *out, int numbits,
68 : : long length, DES_key_schedule *schedule,
69 : : DES_cblock *ivec)
70 : : {
71 : 2 : register DES_LONG d0,d1,vv0,vv1,v0,v1,n=(numbits+7)/8;
72 : : register DES_LONG mask0,mask1;
73 : 2 : register long l=length;
74 : 2 : register int num=numbits;
75 : : DES_LONG ti[2];
76 : : unsigned char *iv;
77 : :
78 [ + - ]: 2 : if (num > 64) return;
79 [ + - ]: 2 : if (num > 32)
80 : : {
81 : 2 : mask0=0xffffffffL;
82 [ - + ]: 2 : if (num >= 64)
83 : : mask1=mask0;
84 : : else
85 : 0 : mask1=(1L<<(num-32))-1;
86 : : }
87 : : else
88 : : {
89 [ # # ]: 0 : if (num == 32)
90 : : mask0=0xffffffffL;
91 : : else
92 : 0 : mask0=(1L<<num)-1;
93 : : mask1=0x00000000L;
94 : : }
95 : :
96 : 2 : iv = &(*ivec)[0];
97 : 2 : c2l(iv,v0);
98 : 2 : c2l(iv,v1);
99 : 2 : ti[0]=v0;
100 : 2 : ti[1]=v1;
101 [ + + ]: 8 : while (l-- > 0)
102 : : {
103 : 6 : ti[0]=v0;
104 : 6 : ti[1]=v1;
105 : 6 : DES_encrypt1((DES_LONG *)ti,schedule,DES_ENCRYPT);
106 : 6 : vv0=ti[0];
107 : 6 : vv1=ti[1];
108 [ + - - - : 6 : c2ln(in,d0,d1,n);
- - - -
- ]
109 : 6 : in+=n;
110 : 6 : d0=(d0^vv0)&mask0;
111 : 6 : d1=(d1^vv1)&mask1;
112 [ + - - - : 6 : l2cn(d0,d1,out,n);
- - - -
- ]
113 : 6 : out+=n;
114 : :
115 [ + - ]: 6 : if (num == 32)
116 : : { v0=v1; v1=vv0; }
117 [ - + ]: 6 : else if (num == 64)
118 : : { v0=vv0; v1=vv1; }
119 [ # # ]: 0 : else if (num > 32) /* && num != 64 */
120 : : {
121 : 0 : v0=((v1>>(num-32))|(vv0<<(64-num)))&0xffffffffL;
122 : 0 : v1=((vv0>>(num-32))|(vv1<<(64-num)))&0xffffffffL;
123 : : }
124 : : else /* num < 32 */
125 : : {
126 : 0 : v0=((v0>>num)|(v1<<(32-num)))&0xffffffffL;
127 : 6 : v1=((v1>>num)|(vv0<<(32-num)))&0xffffffffL;
128 : : }
129 : : }
130 : 2 : iv = &(*ivec)[0];
131 : 2 : l2c(v0,iv);
132 : 2 : l2c(v1,iv);
133 : 2 : v0=v1=d0=d1=ti[0]=ti[1]=vv0=vv1=0;
134 : : }
135 : :
|
