1 /* crypto/des/cfb_enc.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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.
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).
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.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
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)"
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
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.]
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
67 void des_cfb_encrypt(const unsigned char *in
, unsigned char *out
, int numbits
,
68 long length
, des_key_schedule schedule
, des_cblock
*ivec
, int enc
)
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
;
83 else mask1
=(1L<<(num
-32))-1;
89 else mask0
=(1L<<num
)-1;
103 des_encrypt1((DES_LONG
*)ti
,schedule
,DES_ENCRYPT
);
110 /* 30-08-94 - eay - changed because l>>32 and
111 * l<<32 are bad under gcc :-( */
116 else if (num
> 32) /* && num != 64 */
118 v0
=((v1
>>(num
-32))|(d0
<<(64-num
)))&0xffffffffL
;
119 v1
=((d0
>>(num
-32))|(d1
<<(64-num
)))&0xffffffffL
;
123 v0
=((v0
>>num
)|(v1
<<(32-num
)))&0xffffffffL
;
124 v1
=((v1
>>num
)|(d0
<<(32-num
)))&0xffffffffL
;
135 des_encrypt1((DES_LONG
*)ti
,schedule
,DES_ENCRYPT
);
138 /* 30-08-94 - eay - changed because l>>32 and
139 * l<<32 are bad under gcc :-( */
144 else if (num
> 32) /* && num != 64 */
146 v0
=((v1
>>(num
-32))|(d0
<<(64-num
)))&0xffffffffL
;
147 v1
=((d0
>>(num
-32))|(d1
<<(64-num
)))&0xffffffffL
;
151 v0
=((v0
>>num
)|(v1
<<(32-num
)))&0xffffffffL
;
152 v1
=((v1
>>num
)|(d0
<<(32-num
)))&0xffffffffL
;
163 v0
=v1
=d0
=d1
=ti
[0]=ti
[1]=0;