des_ofb64_encrypt(in,out,length,schedule,ivec,num)1 /* crypto/des/ofb64enc.c */
2 /* Copyright (C) 1995-1997 Eric Young (eay@mincom.oz.au)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@mincom.oz.au).
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@mincom.oz.au).
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@mincom.oz.au)"
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@mincom.oz.au)"
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 ofb 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 void des_ofb64_encrypt(in, out, length, schedule, ivec, num)
66 register unsigned char *in;
67 register unsigned char *out;
68 long length;
69 des_key_schedule schedule;
70 des_cblock (*ivec);
71 int *num;
72 {
73 register DES_LONG v0,v1,t;
74 register int n= *num;
75 register long l=length;
76 des_cblock d;
77 register char *dp;
78 DES_LONG ti[2];
79 unsigned char *iv;
80 int save=0;
81
82 iv=(unsigned char *)ivec;
83 c2l(iv,v0);
84 c2l(iv,v1);
85 ti[0]=v0;
86 ti[1]=v1;
87 dp=(char *)d;
88 l2c(v0,dp);
89 l2c(v1,dp);
90 while (l--)
91 {
92 if (n == 0)
93 {
94 des_encrypt((DES_LONG *)ti,schedule,DES_ENCRYPT);
95 dp=(char *)d;
96 t=ti[0]; l2c(t,dp);
97 t=ti[1]; l2c(t,dp);
98 save++;
99 }
100 *(out++)= *(in++)^d[n];
101 n=(n+1)&0x07;
102 }
103 if (save)
104 {
105 v0=ti[0];
106 v1=ti[1];
107 iv=(unsigned char *)ivec;
108 l2c(v0,iv);
109 l2c(v1,iv);
110 }
111 t=v0=v1=ti[0]=ti[1]=0;
112 *num=n;
113 }
114
115