diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /crypto/arc4.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'crypto/arc4.c')
-rw-r--r-- | crypto/arc4.c | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/crypto/arc4.c b/crypto/arc4.c new file mode 100644 index 000000000000..9efbcaae88a1 --- /dev/null +++ b/crypto/arc4.c | |||
@@ -0,0 +1,103 @@ | |||
1 | /* | ||
2 | * Cryptographic API | ||
3 | * | ||
4 | * ARC4 Cipher Algorithm | ||
5 | * | ||
6 | * Jon Oberheide <jon@oberheide.org> | ||
7 | * | ||
8 | * This program is free software; you can redistribute it and/or modify | ||
9 | * it under the terms of the GNU General Public License as published by | ||
10 | * the Free Software Foundation; either version 2 of the License, or | ||
11 | * (at your option) any later version. | ||
12 | * | ||
13 | */ | ||
14 | #include <linux/module.h> | ||
15 | #include <linux/init.h> | ||
16 | #include <linux/crypto.h> | ||
17 | |||
18 | #define ARC4_MIN_KEY_SIZE 1 | ||
19 | #define ARC4_MAX_KEY_SIZE 256 | ||
20 | #define ARC4_BLOCK_SIZE 1 | ||
21 | |||
22 | struct arc4_ctx { | ||
23 | u8 S[256]; | ||
24 | u8 x, y; | ||
25 | }; | ||
26 | |||
27 | static int arc4_set_key(void *ctx_arg, const u8 *in_key, unsigned int key_len, u32 *flags) | ||
28 | { | ||
29 | struct arc4_ctx *ctx = ctx_arg; | ||
30 | int i, j = 0, k = 0; | ||
31 | |||
32 | ctx->x = 1; | ||
33 | ctx->y = 0; | ||
34 | |||
35 | for(i = 0; i < 256; i++) | ||
36 | ctx->S[i] = i; | ||
37 | |||
38 | for(i = 0; i < 256; i++) | ||
39 | { | ||
40 | u8 a = ctx->S[i]; | ||
41 | j = (j + in_key[k] + a) & 0xff; | ||
42 | ctx->S[i] = ctx->S[j]; | ||
43 | ctx->S[j] = a; | ||
44 | if(++k >= key_len) | ||
45 | k = 0; | ||
46 | } | ||
47 | |||
48 | return 0; | ||
49 | } | ||
50 | |||
51 | static void arc4_crypt(void *ctx_arg, u8 *out, const u8 *in) | ||
52 | { | ||
53 | struct arc4_ctx *ctx = ctx_arg; | ||
54 | |||
55 | u8 *const S = ctx->S; | ||
56 | u8 x = ctx->x; | ||
57 | u8 y = ctx->y; | ||
58 | u8 a, b; | ||
59 | |||
60 | a = S[x]; | ||
61 | y = (y + a) & 0xff; | ||
62 | b = S[y]; | ||
63 | S[x] = b; | ||
64 | S[y] = a; | ||
65 | x = (x + 1) & 0xff; | ||
66 | *out++ = *in ^ S[(a + b) & 0xff]; | ||
67 | |||
68 | ctx->x = x; | ||
69 | ctx->y = y; | ||
70 | } | ||
71 | |||
72 | static struct crypto_alg arc4_alg = { | ||
73 | .cra_name = "arc4", | ||
74 | .cra_flags = CRYPTO_ALG_TYPE_CIPHER, | ||
75 | .cra_blocksize = ARC4_BLOCK_SIZE, | ||
76 | .cra_ctxsize = sizeof(struct arc4_ctx), | ||
77 | .cra_module = THIS_MODULE, | ||
78 | .cra_list = LIST_HEAD_INIT(arc4_alg.cra_list), | ||
79 | .cra_u = { .cipher = { | ||
80 | .cia_min_keysize = ARC4_MIN_KEY_SIZE, | ||
81 | .cia_max_keysize = ARC4_MAX_KEY_SIZE, | ||
82 | .cia_setkey = arc4_set_key, | ||
83 | .cia_encrypt = arc4_crypt, | ||
84 | .cia_decrypt = arc4_crypt } } | ||
85 | }; | ||
86 | |||
87 | static int __init arc4_init(void) | ||
88 | { | ||
89 | return crypto_register_alg(&arc4_alg); | ||
90 | } | ||
91 | |||
92 | |||
93 | static void __exit arc4_exit(void) | ||
94 | { | ||
95 | crypto_unregister_alg(&arc4_alg); | ||
96 | } | ||
97 | |||
98 | module_init(arc4_init); | ||
99 | module_exit(arc4_exit); | ||
100 | |||
101 | MODULE_LICENSE("GPL"); | ||
102 | MODULE_DESCRIPTION("ARC4 Cipher Algorithm"); | ||
103 | MODULE_AUTHOR("Jon Oberheide <jon@oberheide.org>"); | ||