diff options
author | Colin Watson <cjwatson@debian.org> | 2003-09-23 18:08:35 +0000 |
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committer | Colin Watson <cjwatson@debian.org> | 2003-09-23 18:08:35 +0000 |
commit | d59fd3e421aa81b8e5e118f3f806081df2aca879 (patch) | |
tree | 356a4e607edc979c625bb33db63c656d771478bd /cipher-ctr.c | |
parent | 7505658c58e96b8d270f1928a0e1fa7f3e0c266b (diff) | |
parent | 45431c9b4677608680cd071768cbf156b316a7e8 (diff) |
Merge 3.7.1p2 to the trunk. I have absolutely no idea yet whether this will
work.
Diffstat (limited to 'cipher-ctr.c')
-rw-r--r-- | cipher-ctr.c | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/cipher-ctr.c b/cipher-ctr.c new file mode 100644 index 000000000..a2bab5c14 --- /dev/null +++ b/cipher-ctr.c | |||
@@ -0,0 +1,141 @@ | |||
1 | /* | ||
2 | * Copyright (c) 2003 Markus Friedl <markus@openbsd.org> | ||
3 | * | ||
4 | * Permission to use, copy, modify, and distribute this software for any | ||
5 | * purpose with or without fee is hereby granted, provided that the above | ||
6 | * copyright notice and this permission notice appear in all copies. | ||
7 | * | ||
8 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES | ||
9 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF | ||
10 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR | ||
11 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES | ||
12 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN | ||
13 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF | ||
14 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. | ||
15 | */ | ||
16 | #include "includes.h" | ||
17 | RCSID("$OpenBSD: cipher-ctr.c,v 1.2 2003/06/17 18:14:23 markus Exp $"); | ||
18 | |||
19 | #include <openssl/evp.h> | ||
20 | |||
21 | #include "log.h" | ||
22 | #include "xmalloc.h" | ||
23 | |||
24 | #if OPENSSL_VERSION_NUMBER < 0x00907000L | ||
25 | #include "rijndael.h" | ||
26 | #define AES_KEY rijndael_ctx | ||
27 | #define AES_BLOCK_SIZE 16 | ||
28 | #define AES_encrypt(a, b, c) rijndael_encrypt(c, a, b) | ||
29 | #define AES_set_encrypt_key(a, b, c) rijndael_set_key(c, (char *)a, b, 1) | ||
30 | #else | ||
31 | #include <openssl/aes.h> | ||
32 | #endif | ||
33 | |||
34 | const EVP_CIPHER *evp_aes_128_ctr(void); | ||
35 | void ssh_aes_ctr_iv(EVP_CIPHER_CTX *, int, u_char *, u_int); | ||
36 | |||
37 | struct ssh_aes_ctr_ctx | ||
38 | { | ||
39 | AES_KEY aes_ctx; | ||
40 | u_char aes_counter[AES_BLOCK_SIZE]; | ||
41 | }; | ||
42 | |||
43 | /* | ||
44 | * increment counter 'ctr', | ||
45 | * the counter is of size 'len' bytes and stored in network-byte-order. | ||
46 | * (LSB at ctr[len-1], MSB at ctr[0]) | ||
47 | */ | ||
48 | static void | ||
49 | ssh_ctr_inc(u_char *ctr, u_int len) | ||
50 | { | ||
51 | int i; | ||
52 | |||
53 | for (i = len - 1; i >= 0; i--) | ||
54 | if (++ctr[i]) /* continue on overflow */ | ||
55 | return; | ||
56 | } | ||
57 | |||
58 | static int | ||
59 | ssh_aes_ctr(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, | ||
60 | u_int len) | ||
61 | { | ||
62 | struct ssh_aes_ctr_ctx *c; | ||
63 | u_int n = 0; | ||
64 | u_char buf[AES_BLOCK_SIZE]; | ||
65 | |||
66 | if (len == 0) | ||
67 | return (1); | ||
68 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) | ||
69 | return (0); | ||
70 | |||
71 | while ((len--) > 0) { | ||
72 | if (n == 0) { | ||
73 | AES_encrypt(c->aes_counter, buf, &c->aes_ctx); | ||
74 | ssh_ctr_inc(c->aes_counter, AES_BLOCK_SIZE); | ||
75 | } | ||
76 | *(dest++) = *(src++) ^ buf[n]; | ||
77 | n = (n + 1) % AES_BLOCK_SIZE; | ||
78 | } | ||
79 | return (1); | ||
80 | } | ||
81 | |||
82 | static int | ||
83 | ssh_aes_ctr_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, | ||
84 | int enc) | ||
85 | { | ||
86 | struct ssh_aes_ctr_ctx *c; | ||
87 | |||
88 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | ||
89 | c = xmalloc(sizeof(*c)); | ||
90 | EVP_CIPHER_CTX_set_app_data(ctx, c); | ||
91 | } | ||
92 | if (key != NULL) | ||
93 | AES_set_encrypt_key(key, ctx->key_len * 8, &c->aes_ctx); | ||
94 | if (iv != NULL) | ||
95 | memcpy(c->aes_counter, iv, AES_BLOCK_SIZE); | ||
96 | return (1); | ||
97 | } | ||
98 | |||
99 | static int | ||
100 | ssh_aes_ctr_cleanup(EVP_CIPHER_CTX *ctx) | ||
101 | { | ||
102 | struct ssh_aes_ctr_ctx *c; | ||
103 | |||
104 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) { | ||
105 | memset(c, 0, sizeof(*c)); | ||
106 | xfree(c); | ||
107 | EVP_CIPHER_CTX_set_app_data(ctx, NULL); | ||
108 | } | ||
109 | return (1); | ||
110 | } | ||
111 | |||
112 | void | ||
113 | ssh_aes_ctr_iv(EVP_CIPHER_CTX *evp, int doset, u_char * iv, u_int len) | ||
114 | { | ||
115 | struct ssh_aes_ctr_ctx *c; | ||
116 | |||
117 | if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL) | ||
118 | fatal("ssh_aes_ctr_iv: no context"); | ||
119 | if (doset) | ||
120 | memcpy(c->aes_counter, iv, len); | ||
121 | else | ||
122 | memcpy(iv, c->aes_counter, len); | ||
123 | } | ||
124 | |||
125 | const EVP_CIPHER * | ||
126 | evp_aes_128_ctr(void) | ||
127 | { | ||
128 | static EVP_CIPHER aes_ctr; | ||
129 | |||
130 | memset(&aes_ctr, 0, sizeof(EVP_CIPHER)); | ||
131 | aes_ctr.nid = NID_undef; | ||
132 | aes_ctr.block_size = AES_BLOCK_SIZE; | ||
133 | aes_ctr.iv_len = AES_BLOCK_SIZE; | ||
134 | aes_ctr.key_len = 16; | ||
135 | aes_ctr.init = ssh_aes_ctr_init; | ||
136 | aes_ctr.cleanup = ssh_aes_ctr_cleanup; | ||
137 | aes_ctr.do_cipher = ssh_aes_ctr; | ||
138 | aes_ctr.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH | | ||
139 | EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CUSTOM_IV; | ||
140 | return (&aes_ctr); | ||
141 | } | ||