/src/openssl/crypto/des/ofb_enc.c
Line | Count | Source (jump to first uncovered line) |
1 | | /* |
2 | | * Copyright 1995-2020 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 | | /* |
11 | | * DES low level APIs are deprecated for public use, but still ok for internal |
12 | | * use. |
13 | | */ |
14 | | #include "internal/deprecated.h" |
15 | | |
16 | | #include "des_local.h" |
17 | | |
18 | | /* |
19 | | * The input and output are loaded in multiples of 8 bits. What this means is |
20 | | * that if you have numbits=12 and length=2 the first 12 bits will be |
21 | | * retrieved from the first byte and half the second. The second 12 bits |
22 | | * will come from the 3rd and half the 4th byte. |
23 | | */ |
24 | | void DES_ofb_encrypt(const unsigned char *in, unsigned char *out, int numbits, |
25 | | long length, DES_key_schedule *schedule, |
26 | | DES_cblock *ivec) |
27 | 0 | { |
28 | 0 | register DES_LONG d0, d1, vv0, vv1, v0, v1, n = (numbits + 7) / 8; |
29 | 0 | register DES_LONG mask0, mask1; |
30 | 0 | register long l = length; |
31 | 0 | register int num = numbits; |
32 | 0 | DES_LONG ti[2]; |
33 | 0 | unsigned char *iv; |
34 | |
|
35 | 0 | if (num > 64) |
36 | 0 | return; |
37 | 0 | if (num > 32) { |
38 | 0 | mask0 = 0xffffffffL; |
39 | 0 | if (num >= 64) |
40 | 0 | mask1 = mask0; |
41 | 0 | else |
42 | 0 | mask1 = (1L << (num - 32)) - 1; |
43 | 0 | } else { |
44 | 0 | if (num == 32) |
45 | 0 | mask0 = 0xffffffffL; |
46 | 0 | else |
47 | 0 | mask0 = (1L << num) - 1; |
48 | 0 | mask1 = 0x00000000L; |
49 | 0 | } |
50 | |
|
51 | 0 | iv = &(*ivec)[0]; |
52 | 0 | c2l(iv, v0); |
53 | 0 | c2l(iv, v1); |
54 | 0 | ti[0] = v0; |
55 | 0 | ti[1] = v1; |
56 | 0 | while (l-- > 0) { |
57 | 0 | ti[0] = v0; |
58 | 0 | ti[1] = v1; |
59 | 0 | DES_encrypt1((DES_LONG *)ti, schedule, DES_ENCRYPT); |
60 | 0 | vv0 = ti[0]; |
61 | 0 | vv1 = ti[1]; |
62 | 0 | c2ln(in, d0, d1, n); |
63 | 0 | in += n; |
64 | 0 | d0 = (d0 ^ vv0) & mask0; |
65 | 0 | d1 = (d1 ^ vv1) & mask1; |
66 | 0 | l2cn(d0, d1, out, n); |
67 | 0 | out += n; |
68 | |
|
69 | 0 | if (num == 32) { |
70 | 0 | v0 = v1; |
71 | 0 | v1 = vv0; |
72 | 0 | } else if (num == 64) { |
73 | 0 | v0 = vv0; |
74 | 0 | v1 = vv1; |
75 | 0 | } else if (num > 32) { /* && num != 64 */ |
76 | 0 | v0 = ((v1 >> (num - 32)) | (vv0 << (64 - num))) & 0xffffffffL; |
77 | 0 | v1 = ((vv0 >> (num - 32)) | (vv1 << (64 - num))) & 0xffffffffL; |
78 | 0 | } else { /* num < 32 */ |
79 | |
|
80 | 0 | v0 = ((v0 >> num) | (v1 << (32 - num))) & 0xffffffffL; |
81 | 0 | v1 = ((v1 >> num) | (vv0 << (32 - num))) & 0xffffffffL; |
82 | 0 | } |
83 | 0 | } |
84 | 0 | iv = &(*ivec)[0]; |
85 | 0 | l2c(v0, iv); |
86 | 0 | l2c(v1, iv); |
87 | 0 | v0 = v1 = d0 = d1 = ti[0] = ti[1] = vv0 = vv1 = 0; |
88 | 0 | } |