1 | /* |
2 | * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved. |
3 | * |
4 | * Licensed under the Apache License 2.0 (the "License"). You may not use |
5 | * this file except in compliance with the License. You can obtain a copy |
6 | * in the file LICENSE in the source distribution or at |
7 | * https://www.openssl.org/source/license.html |
8 | */ |
9 | |
10 | #include "e_os.h" |
11 | #include "des_local.h" |
12 | #include <assert.h> |
13 | |
14 | /* |
15 | * The input and output are loaded in multiples of 8 bits. What this means is |
16 | * that if you hame numbits=12 and length=2 the first 12 bits will be |
17 | * retrieved from the first byte and half the second. The second 12 bits |
18 | * will come from the 3rd and half the 4th byte. |
19 | */ |
20 | /* |
21 | * Until Aug 1 2003 this function did not correctly implement CFB-r, so it |
22 | * will not be compatible with any encryption prior to that date. Ben. |
23 | */ |
24 | void DES_cfb_encrypt(const unsigned char *in, unsigned char *out, int numbits, |
25 | long length, DES_key_schedule *schedule, |
26 | DES_cblock *ivec, int enc) |
27 | { |
28 | register DES_LONG d0, d1, v0, v1; |
29 | register unsigned long l = length; |
30 | register int num = numbits / 8, n = (numbits + 7) / 8, i, rem = |
31 | numbits % 8; |
32 | DES_LONG ti[2]; |
33 | unsigned char *iv; |
34 | #ifndef L_ENDIAN |
35 | unsigned char ovec[16]; |
36 | #else |
37 | unsigned int sh[4]; |
38 | unsigned char *ovec = (unsigned char *)sh; |
39 | |
40 | /* I kind of count that compiler optimizes away this assertion, */ |
41 | assert(sizeof(sh[0]) == 4); /* as this holds true for all, */ |
42 | /* but 16-bit platforms... */ |
43 | |
44 | #endif |
45 | |
46 | if (numbits <= 0 || numbits > 64) |
47 | return; |
48 | iv = &(*ivec)[0]; |
49 | c2l(iv, v0); |
50 | c2l(iv, v1); |
51 | if (enc) { |
52 | while (l >= (unsigned long)n) { |
53 | l -= n; |
54 | ti[0] = v0; |
55 | ti[1] = v1; |
56 | DES_encrypt1((DES_LONG *)ti, schedule, DES_ENCRYPT); |
57 | c2ln(in, d0, d1, n); |
58 | in += n; |
59 | d0 ^= ti[0]; |
60 | d1 ^= ti[1]; |
61 | l2cn(d0, d1, out, n); |
62 | out += n; |
63 | /* |
64 | * 30-08-94 - eay - changed because l>>32 and l<<32 are bad under |
65 | * gcc :-( |
66 | */ |
67 | if (numbits == 32) { |
68 | v0 = v1; |
69 | v1 = d0; |
70 | } else if (numbits == 64) { |
71 | v0 = d0; |
72 | v1 = d1; |
73 | } else { |
74 | #ifndef L_ENDIAN |
75 | iv = &ovec[0]; |
76 | l2c(v0, iv); |
77 | l2c(v1, iv); |
78 | l2c(d0, iv); |
79 | l2c(d1, iv); |
80 | #else |
81 | sh[0] = v0, sh[1] = v1, sh[2] = d0, sh[3] = d1; |
82 | #endif |
83 | if (rem == 0) |
84 | memmove(ovec, ovec + num, 8); |
85 | else |
86 | for (i = 0; i < 8; ++i) |
87 | ovec[i] = ovec[i + num] << rem | |
88 | ovec[i + num + 1] >> (8 - rem); |
89 | #ifdef L_ENDIAN |
90 | v0 = sh[0], v1 = sh[1]; |
91 | #else |
92 | iv = &ovec[0]; |
93 | c2l(iv, v0); |
94 | c2l(iv, v1); |
95 | #endif |
96 | } |
97 | } |
98 | } else { |
99 | while (l >= (unsigned long)n) { |
100 | l -= n; |
101 | ti[0] = v0; |
102 | ti[1] = v1; |
103 | DES_encrypt1((DES_LONG *)ti, schedule, DES_ENCRYPT); |
104 | c2ln(in, d0, d1, n); |
105 | in += n; |
106 | /* |
107 | * 30-08-94 - eay - changed because l>>32 and l<<32 are bad under |
108 | * gcc :-( |
109 | */ |
110 | if (numbits == 32) { |
111 | v0 = v1; |
112 | v1 = d0; |
113 | } else if (numbits == 64) { |
114 | v0 = d0; |
115 | v1 = d1; |
116 | } else { |
117 | #ifndef L_ENDIAN |
118 | iv = &ovec[0]; |
119 | l2c(v0, iv); |
120 | l2c(v1, iv); |
121 | l2c(d0, iv); |
122 | l2c(d1, iv); |
123 | #else |
124 | sh[0] = v0, sh[1] = v1, sh[2] = d0, sh[3] = d1; |
125 | #endif |
126 | if (rem == 0) |
127 | memmove(ovec, ovec + num, 8); |
128 | else |
129 | for (i = 0; i < 8; ++i) |
130 | ovec[i] = ovec[i + num] << rem | |
131 | ovec[i + num + 1] >> (8 - rem); |
132 | #ifdef L_ENDIAN |
133 | v0 = sh[0], v1 = sh[1]; |
134 | #else |
135 | iv = &ovec[0]; |
136 | c2l(iv, v0); |
137 | c2l(iv, v1); |
138 | #endif |
139 | } |
140 | d0 ^= ti[0]; |
141 | d1 ^= ti[1]; |
142 | l2cn(d0, d1, out, n); |
143 | out += n; |
144 | } |
145 | } |
146 | iv = &(*ivec)[0]; |
147 | l2c(v0, iv); |
148 | l2c(v1, iv); |
149 | v0 = v1 = d0 = d1 = ti[0] = ti[1] = 0; |
150 | } |
151 | |