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Diffstat (limited to 'src/lib/libcrypto/aes/aes_ctr.c')
-rw-r--r-- | src/lib/libcrypto/aes/aes_ctr.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/src/lib/libcrypto/aes/aes_ctr.c b/src/lib/libcrypto/aes/aes_ctr.c new file mode 100644 index 0000000000..8e800481de --- /dev/null +++ b/src/lib/libcrypto/aes/aes_ctr.c | |||
@@ -0,0 +1,117 @@ | |||
1 | /* crypto/aes/aes_ctr.c -*- mode:C; c-file-style: "eay" -*- */ | ||
2 | /* ==================================================================== | ||
3 | * Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved. | ||
4 | * | ||
5 | * Redistribution and use in source and binary forms, with or without | ||
6 | * modification, are permitted provided that the following conditions | ||
7 | * are met: | ||
8 | * | ||
9 | * 1. Redistributions of source code must retain the above copyright | ||
10 | * notice, this list of conditions and the following disclaimer. | ||
11 | * | ||
12 | * 2. Redistributions in binary form must reproduce the above copyright | ||
13 | * notice, this list of conditions and the following disclaimer in | ||
14 | * the documentation and/or other materials provided with the | ||
15 | * distribution. | ||
16 | * | ||
17 | * 3. All advertising materials mentioning features or use of this | ||
18 | * software must display the following acknowledgment: | ||
19 | * "This product includes software developed by the OpenSSL Project | ||
20 | * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" | ||
21 | * | ||
22 | * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to | ||
23 | * endorse or promote products derived from this software without | ||
24 | * prior written permission. For written permission, please contact | ||
25 | * openssl-core@openssl.org. | ||
26 | * | ||
27 | * 5. Products derived from this software may not be called "OpenSSL" | ||
28 | * nor may "OpenSSL" appear in their names without prior written | ||
29 | * permission of the OpenSSL Project. | ||
30 | * | ||
31 | * 6. Redistributions of any form whatsoever must retain the following | ||
32 | * acknowledgment: | ||
33 | * "This product includes software developed by the OpenSSL Project | ||
34 | * for use in the OpenSSL Toolkit (http://www.openssl.org/)" | ||
35 | * | ||
36 | * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY | ||
37 | * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | ||
38 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | ||
39 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR | ||
40 | * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | ||
41 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | ||
42 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | ||
43 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | ||
44 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, | ||
45 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | ||
46 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED | ||
47 | * OF THE POSSIBILITY OF SUCH DAMAGE. | ||
48 | * ==================================================================== | ||
49 | * | ||
50 | */ | ||
51 | |||
52 | #include <assert.h> | ||
53 | #include <openssl/aes.h> | ||
54 | #include "aes_locl.h" | ||
55 | |||
56 | /* NOTE: CTR mode is big-endian. The rest of the AES code | ||
57 | * is endian-neutral. */ | ||
58 | |||
59 | /* increment counter (128-bit int) by 2^64 */ | ||
60 | static void AES_ctr128_inc(unsigned char *counter) { | ||
61 | unsigned long c; | ||
62 | |||
63 | /* Grab 3rd dword of counter and increment */ | ||
64 | #ifdef L_ENDIAN | ||
65 | c = GETU32(counter + 8); | ||
66 | c++; | ||
67 | PUTU32(counter + 8, c); | ||
68 | #else | ||
69 | c = GETU32(counter + 4); | ||
70 | c++; | ||
71 | PUTU32(counter + 4, c); | ||
72 | #endif | ||
73 | |||
74 | /* if no overflow, we're done */ | ||
75 | if (c) | ||
76 | return; | ||
77 | |||
78 | /* Grab top dword of counter and increment */ | ||
79 | #ifdef L_ENDIAN | ||
80 | c = GETU32(counter + 12); | ||
81 | c++; | ||
82 | PUTU32(counter + 12, c); | ||
83 | #else | ||
84 | c = GETU32(counter + 0); | ||
85 | c++; | ||
86 | PUTU32(counter + 0, c); | ||
87 | #endif | ||
88 | |||
89 | } | ||
90 | |||
91 | /* The input encrypted as though 128bit counter mode is being | ||
92 | * used. The extra state information to record how much of the | ||
93 | * 128bit block we have used is contained in *num; | ||
94 | */ | ||
95 | void AES_ctr128_encrypt(const unsigned char *in, unsigned char *out, | ||
96 | const unsigned long length, const AES_KEY *key, | ||
97 | unsigned char *counter, unsigned int *num) { | ||
98 | |||
99 | unsigned int n; | ||
100 | unsigned long l=length; | ||
101 | unsigned char tmp[AES_BLOCK_SIZE]; | ||
102 | |||
103 | assert(in && out && key && counter && num); | ||
104 | |||
105 | n = *num; | ||
106 | |||
107 | while (l--) { | ||
108 | if (n == 0) { | ||
109 | AES_ctr128_inc(counter); | ||
110 | AES_encrypt(counter, tmp, key); | ||
111 | } | ||
112 | *(out++) = *(in++) ^ tmp[n]; | ||
113 | n = (n+1) % AES_BLOCK_SIZE; | ||
114 | } | ||
115 | |||
116 | *num=n; | ||
117 | } | ||