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4f22f405 RS |
1 | /* |
2 | * Copyright 2008-2016 The OpenSSL Project Authors. All Rights Reserved. | |
85b2c0ce | 3 | * |
81cae8ce | 4 | * Licensed under the Apache License 2.0 (the "License"). You may not use |
4f22f405 RS |
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 | |
85b2c0ce AP |
8 | */ |
9 | ||
85b2c0ce | 10 | #include <string.h> |
459b15d4 | 11 | #include <openssl/crypto.h> |
25f2138b | 12 | #include "crypto/modes.h" |
85b2c0ce | 13 | |
0f113f3e MC |
14 | /* |
15 | * The input and output encrypted as though 128bit ofb mode is being used. | |
16 | * The extra state information to record how much of the 128bit block we have | |
17 | * used is contained in *num; | |
85b2c0ce AP |
18 | */ |
19 | void CRYPTO_ofb128_encrypt(const unsigned char *in, unsigned char *out, | |
0f113f3e MC |
20 | size_t len, const void *key, |
21 | unsigned char ivec[16], int *num, block128_f block) | |
85b2c0ce | 22 | { |
0f113f3e MC |
23 | unsigned int n; |
24 | size_t l = 0; | |
85b2c0ce | 25 | |
0f113f3e | 26 | n = *num; |
85b2c0ce AP |
27 | |
28 | #if !defined(OPENSSL_SMALL_FOOTPRINT) | |
0f113f3e MC |
29 | if (16 % sizeof(size_t) == 0) { /* always true actually */ |
30 | do { | |
31 | while (n && len) { | |
32 | *(out++) = *(in++) ^ ivec[n]; | |
33 | --len; | |
34 | n = (n + 1) % 16; | |
35 | } | |
36 | # if defined(STRICT_ALIGNMENT) | |
37 | if (((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != | |
38 | 0) | |
39 | break; | |
40 | # endif | |
41 | while (len >= 16) { | |
42 | (*block) (ivec, ivec, key); | |
43 | for (; n < 16; n += sizeof(size_t)) | |
44 | *(size_t *)(out + n) = | |
45 | *(size_t *)(in + n) ^ *(size_t *)(ivec + n); | |
46 | len -= 16; | |
47 | out += 16; | |
48 | in += 16; | |
49 | n = 0; | |
50 | } | |
51 | if (len) { | |
52 | (*block) (ivec, ivec, key); | |
53 | while (len--) { | |
54 | out[n] = in[n] ^ ivec[n]; | |
55 | ++n; | |
56 | } | |
57 | } | |
58 | *num = n; | |
59 | return; | |
60 | } while (0); | |
61 | } | |
62 | /* the rest would be commonly eliminated by x86* compiler */ | |
85b2c0ce | 63 | #endif |
0f113f3e MC |
64 | while (l < len) { |
65 | if (n == 0) { | |
66 | (*block) (ivec, ivec, key); | |
67 | } | |
68 | out[l] = in[l] ^ ivec[n]; | |
69 | ++l; | |
70 | n = (n + 1) % 16; | |
71 | } | |
85b2c0ce | 72 | |
0f113f3e | 73 | *num = n; |
85b2c0ce | 74 | } |