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1 : : /* crypto/des/cfb_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 "e_os.h"
60 : : #include "des_locl.h"
61 : : #include <assert.h>
62 : :
63 : : /* The input and output are loaded in multiples of 8 bits.
64 : : * What this means is that if you hame numbits=12 and length=2
65 : : * the first 12 bits will be retrieved from the first byte and half
66 : : * the second. The second 12 bits will come from the 3rd and half the 4th
67 : : * byte.
68 : : */
69 : : /* Until Aug 1 2003 this function did not correctly implement CFB-r, so it
70 : : * will not be compatible with any encryption prior to that date. Ben. */
71 : 58 : void DES_cfb_encrypt(const unsigned char *in, unsigned char *out, int numbits,
72 : : long length, DES_key_schedule *schedule, DES_cblock *ivec,
73 : : int enc)
74 : : {
75 : : register DES_LONG d0,d1,v0,v1;
76 : 58 : register unsigned long l=length;
77 : 58 : register int num=numbits/8,n=(numbits+7)/8,i,rem=numbits%8;
78 : : DES_LONG ti[2];
79 : : unsigned char *iv;
80 : : #ifndef L_ENDIAN
81 : : unsigned char ovec[16];
82 : : #else
83 : : unsigned int sh[4];
84 : 58 : unsigned char *ovec=(unsigned char *)sh;
85 : :
86 : : /* I kind of count that compiler optimizes away this assertioni,*/
87 : : assert (sizeof(sh[0])==4); /* as this holds true for all, */
88 : : /* but 16-bit platforms... */
89 : :
90 : : #endif
91 : :
92 [ + - ]: 58 : if (numbits<=0 || numbits > 64) return;
93 : 58 : iv = &(*ivec)[0];
94 : 58 : c2l(iv,v0);
95 : 58 : c2l(iv,v1);
96 [ + + ]: 58 : if (enc)
97 : : {
98 [ + + ]: 102 : while (l >= (unsigned long)n)
99 : : {
100 : 73 : l-=n;
101 : 73 : ti[0]=v0;
102 : 73 : ti[1]=v1;
103 : 73 : DES_encrypt1((DES_LONG *)ti,schedule,DES_ENCRYPT);
104 [ + - + - : 73 : c2ln(in,d0,d1,n);
+ - + +
- ]
105 : 73 : in+=n;
106 : 73 : d0^=ti[0];
107 : 73 : d1^=ti[1];
108 [ + - + - : 73 : l2cn(d0,d1,out,n);
+ - + +
- ]
109 : 73 : out+=n;
110 : : /* 30-08-94 - eay - changed because l>>32 and
111 : : * l<<32 are bad under gcc :-( */
112 [ + + ]: 73 : if (numbits == 32)
113 : : { v0=v1; v1=d0; }
114 [ + + ]: 67 : else if (numbits == 64)
115 : : { v0=d0; v1=d1; }
116 : : else
117 : : {
118 : : #ifndef L_ENDIAN
119 : : iv=&ovec[0];
120 : : l2c(v0,iv);
121 : : l2c(v1,iv);
122 : : l2c(d0,iv);
123 : : l2c(d1,iv);
124 : : #else
125 : 64 : sh[0]=v0, sh[1]=v1, sh[2]=d0, sh[3]=d1;
126 : : #endif
127 [ - + ]: 64 : if (rem==0)
128 : 64 : memmove(ovec,ovec+num,8);
129 : : else
130 [ # # ]: 0 : for(i=0 ; i < 8 ; ++i)
131 : 0 : ovec[i]=ovec[i+num]<<rem |
132 : 0 : ovec[i+num+1]>>(8-rem);
133 : : #ifdef L_ENDIAN
134 : 73 : v0=sh[0], v1=sh[1];
135 : : #else
136 : : iv=&ovec[0];
137 : : c2l(iv,v0);
138 : : c2l(iv,v1);
139 : : #endif
140 : : }
141 : : }
142 : : }
143 : : else
144 : : {
145 [ + + ]: 102 : while (l >= (unsigned long)n)
146 : : {
147 : 73 : l-=n;
148 : 73 : ti[0]=v0;
149 : 73 : ti[1]=v1;
150 : 73 : DES_encrypt1((DES_LONG *)ti,schedule,DES_ENCRYPT);
151 [ + - + - : 73 : c2ln(in,d0,d1,n);
+ - + +
- ]
152 : 73 : in+=n;
153 : : /* 30-08-94 - eay - changed because l>>32 and
154 : : * l<<32 are bad under gcc :-( */
155 [ + + ]: 73 : if (numbits == 32)
156 : : { v0=v1; v1=d0; }
157 [ + + ]: 67 : else if (numbits == 64)
158 : : { v0=d0; v1=d1; }
159 : : else
160 : : {
161 : : #ifndef L_ENDIAN
162 : : iv=&ovec[0];
163 : : l2c(v0,iv);
164 : : l2c(v1,iv);
165 : : l2c(d0,iv);
166 : : l2c(d1,iv);
167 : : #else
168 : 64 : sh[0]=v0, sh[1]=v1, sh[2]=d0, sh[3]=d1;
169 : : #endif
170 [ - + ]: 64 : if (rem==0)
171 : 64 : memmove(ovec,ovec+num,8);
172 : : else
173 [ # # ]: 0 : for(i=0 ; i < 8 ; ++i)
174 : 0 : ovec[i]=ovec[i+num]<<rem |
175 : 0 : ovec[i+num+1]>>(8-rem);
176 : : #ifdef L_ENDIAN
177 : 64 : v0=sh[0], v1=sh[1];
178 : : #else
179 : : iv=&ovec[0];
180 : : c2l(iv,v0);
181 : : c2l(iv,v1);
182 : : #endif
183 : : }
184 : 73 : d0^=ti[0];
185 : 73 : d1^=ti[1];
186 [ + - + - : 73 : l2cn(d0,d1,out,n);
+ - + +
- ]
187 : 73 : out+=n;
188 : : }
189 : : }
190 : 58 : iv = &(*ivec)[0];
191 : 58 : l2c(v0,iv);
192 : 58 : l2c(v1,iv);
193 : 58 : v0=v1=d0=d1=ti[0]=ti[1]=0;
194 : : }
195 : :
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