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 "des_local.h" |
11 | |
12 | /* |
13 | * The input and output encrypted as though 64bit cfb mode is being used. |
14 | * The extra state information to record how much of the 64bit block we have |
15 | * used is contained in *num; |
16 | */ |
17 | |
18 | void DES_cfb64_encrypt(const unsigned char *in, unsigned char *out, |
19 | long length, DES_key_schedule *schedule, |
20 | DES_cblock *ivec, int *num, int enc) |
21 | { |
22 | register DES_LONG v0, v1; |
23 | register long l = length; |
24 | register int n = *num; |
25 | DES_LONG ti[2]; |
26 | unsigned char *iv, c, cc; |
27 | |
28 | iv = &(*ivec)[0]; |
29 | if (enc) { |
30 | while (l--) { |
31 | if (n == 0) { |
32 | c2l(iv, v0); |
33 | ti[0] = v0; |
34 | c2l(iv, v1); |
35 | ti[1] = v1; |
36 | DES_encrypt1(ti, schedule, DES_ENCRYPT); |
37 | iv = &(*ivec)[0]; |
38 | v0 = ti[0]; |
39 | l2c(v0, iv); |
40 | v0 = ti[1]; |
41 | l2c(v0, iv); |
42 | iv = &(*ivec)[0]; |
43 | } |
44 | c = *(in++) ^ iv[n]; |
45 | *(out++) = c; |
46 | iv[n] = c; |
47 | n = (n + 1) & 0x07; |
48 | } |
49 | } else { |
50 | while (l--) { |
51 | if (n == 0) { |
52 | c2l(iv, v0); |
53 | ti[0] = v0; |
54 | c2l(iv, v1); |
55 | ti[1] = v1; |
56 | DES_encrypt1(ti, schedule, DES_ENCRYPT); |
57 | iv = &(*ivec)[0]; |
58 | v0 = ti[0]; |
59 | l2c(v0, iv); |
60 | v0 = ti[1]; |
61 | l2c(v0, iv); |
62 | iv = &(*ivec)[0]; |
63 | } |
64 | cc = *(in++); |
65 | c = iv[n]; |
66 | iv[n] = cc; |
67 | *(out++) = c ^ cc; |
68 | n = (n + 1) & 0x07; |
69 | } |
70 | } |
71 | v0 = v1 = ti[0] = ti[1] = c = cc = 0; |
72 | *num = n; |
73 | } |
74 | |