Diffstat (limited to 'pwmanager/libcrypt/cipher/arcfour.c') (more/less context) (ignore whitespace changes)
-rw-r--r-- | pwmanager/libcrypt/cipher/arcfour.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/pwmanager/libcrypt/cipher/arcfour.c b/pwmanager/libcrypt/cipher/arcfour.c new file mode 100644 index 0000000..6bb0555 --- a/dev/null +++ b/pwmanager/libcrypt/cipher/arcfour.c | |||
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1 | /* arcfour.c - The arcfour stream cipher | ||
2 | *Copyright (C) 2000, 2001, 2002, 2003 Free Software Foundation, Inc. | ||
3 | * | ||
4 | * This file is part of Libgcrypt. | ||
5 | * | ||
6 | * Libgcrypt is free software; you can redistribute it and/or modify | ||
7 | * it under the terms of the GNU Lesser general Public License as | ||
8 | * published by the Free Software Foundation; either version 2.1 of | ||
9 | * the License, or (at your option) any later version. | ||
10 | * | ||
11 | * Libgcrypt is distributed in the hope that it will be useful, | ||
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
14 | * GNU Lesser General Public License for more details. | ||
15 | * | ||
16 | * You should have received a copy of the GNU Lesser General Public | ||
17 | * License along with this program; if not, write to the Free Software | ||
18 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA | ||
19 | * | ||
20 | * For a description of the algorithm, see: | ||
21 | * Bruce Schneier: Applied Cryptography. John Wiley & Sons, 1996. | ||
22 | * ISBN 0-471-11709-9. Pages 397 ff. | ||
23 | */ | ||
24 | |||
25 | |||
26 | #include <config.h> | ||
27 | #include <stdio.h> | ||
28 | #include <stdlib.h> | ||
29 | #include <string.h> | ||
30 | #include "types.h" | ||
31 | #include "g10lib.h" | ||
32 | #include "cipher.h" | ||
33 | |||
34 | static const char *selftest(void); | ||
35 | |||
36 | typedef struct { | ||
37 | int idx_i, idx_j; | ||
38 | byte sbox[256]; | ||
39 | } ARCFOUR_context; | ||
40 | |||
41 | static void | ||
42 | do_encrypt_stream( ARCFOUR_context *ctx, | ||
43 | byte *outbuf, const byte *inbuf, unsigned int length ) | ||
44 | { | ||
45 | register int i = ctx->idx_i; | ||
46 | register int j = ctx->idx_j; | ||
47 | register byte *sbox = ctx->sbox; | ||
48 | register int t; | ||
49 | |||
50 | while ( length-- ) | ||
51 | { | ||
52 | i++; | ||
53 | i = i & 255; /* The and-op seems to be faster than the mod-op. */ | ||
54 | j += sbox[i]; | ||
55 | j &= 255; | ||
56 | t = sbox[i]; sbox[i] = sbox[j]; sbox[j] = t; | ||
57 | *outbuf++ = *inbuf++ ^ sbox[(sbox[i] + sbox[j]) & 255]; | ||
58 | } | ||
59 | |||
60 | ctx->idx_i = i; | ||
61 | ctx->idx_j = j; | ||
62 | } | ||
63 | |||
64 | static void | ||
65 | encrypt_stream (void *context, | ||
66 | byte *outbuf, const byte *inbuf, unsigned int length) | ||
67 | { | ||
68 | ARCFOUR_context *ctx = (ARCFOUR_context *) context; | ||
69 | do_encrypt_stream (ctx, outbuf, inbuf, length ); | ||
70 | _gcry_burn_stack (64); | ||
71 | } | ||
72 | |||
73 | |||
74 | static gcry_err_code_t | ||
75 | do_arcfour_setkey (void *context, const byte *key, unsigned int keylen) | ||
76 | { | ||
77 | static int initialized; | ||
78 | static const char* selftest_failed; | ||
79 | int i, j; | ||
80 | byte karr[256]; | ||
81 | ARCFOUR_context *ctx = (ARCFOUR_context *) context; | ||
82 | |||
83 | if (!initialized ) | ||
84 | { | ||
85 | initialized = 1; | ||
86 | selftest_failed = selftest(); | ||
87 | if( selftest_failed ) | ||
88 | log_error ("ARCFOUR selftest failed (%s)\n", selftest_failed ); | ||
89 | } | ||
90 | if( selftest_failed ) | ||
91 | return GPG_ERR_SELFTEST_FAILED; | ||
92 | |||
93 | if( keylen < 40/8 ) /* we want at least 40 bits */ | ||
94 | return GPG_ERR_INV_KEYLEN; | ||
95 | |||
96 | ctx->idx_i = ctx->idx_j = 0; | ||
97 | for (i=0; i < 256; i++ ) | ||
98 | ctx->sbox[i] = i; | ||
99 | for (i=0; i < 256; i++ ) | ||
100 | karr[i] = key[i%keylen]; | ||
101 | for (i=j=0; i < 256; i++ ) | ||
102 | { | ||
103 | int t; | ||
104 | j = (j + ctx->sbox[i] + karr[i]) % 256; | ||
105 | t = ctx->sbox[i]; | ||
106 | ctx->sbox[i] = ctx->sbox[j]; | ||
107 | ctx->sbox[j] = t; | ||
108 | } | ||
109 | memset( karr, 0, 256 ); | ||
110 | |||
111 | return GPG_ERR_NO_ERROR; | ||
112 | } | ||
113 | |||
114 | static gcry_err_code_t | ||
115 | arcfour_setkey ( void *context, const byte *key, unsigned int keylen ) | ||
116 | { | ||
117 | ARCFOUR_context *ctx = (ARCFOUR_context *) context; | ||
118 | gcry_err_code_t rc = do_arcfour_setkey (ctx, key, keylen ); | ||
119 | _gcry_burn_stack (300); | ||
120 | return rc; | ||
121 | } | ||
122 | |||
123 | |||
124 | static const char* | ||
125 | selftest(void) | ||
126 | { | ||
127 | ARCFOUR_context ctx; | ||
128 | byte scratch[16]; | ||
129 | |||
130 | /* Test vector from Cryptlib labeled there: "from the | ||
131 | State/Commerce Department". */ | ||
132 | static byte key_1[] = | ||
133 | { 0x61, 0x8A, 0x63, 0xD2, 0xFB }; | ||
134 | static byte plaintext_1[] = | ||
135 | { 0xDC, 0xEE, 0x4C, 0xF9, 0x2C }; | ||
136 | static const byte ciphertext_1[] = | ||
137 | { 0xF1, 0x38, 0x29, 0xC9, 0xDE }; | ||
138 | |||
139 | arcfour_setkey( &ctx, key_1, sizeof(key_1)); | ||
140 | encrypt_stream( &ctx, scratch, plaintext_1, sizeof(plaintext_1)); | ||
141 | if ( memcmp (scratch, ciphertext_1, sizeof (ciphertext_1))) | ||
142 | return "Arcfour encryption test 1 failed."; | ||
143 | arcfour_setkey( &ctx, key_1, sizeof(key_1)); | ||
144 | encrypt_stream(&ctx, scratch, scratch, sizeof(plaintext_1)); /* decrypt */ | ||
145 | if ( memcmp (scratch, plaintext_1, sizeof (plaintext_1))) | ||
146 | return "Arcfour decryption test 1 failed."; | ||
147 | return NULL; | ||
148 | } | ||
149 | |||
150 | |||
151 | gcry_cipher_spec_t _gcry_cipher_spec_arcfour = | ||
152 | { | ||
153 | "ARCFOUR", NULL, NULL, 1, 128, sizeof (ARCFOUR_context), | ||
154 | arcfour_setkey, NULL, NULL, encrypt_stream, encrypt_stream, | ||
155 | }; | ||
156 | |||