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c9307018 | 1 | /* |
2 | * Copyright (c) 2003 Markus Friedl. All rights reserved. | |
3 | * | |
4 | * Redistribution and use in source and binary forms, with or without | |
5 | * modification, are permitted provided that the following conditions | |
6 | * are met: | |
7 | * 1. Redistributions of source code must retain the above copyright | |
8 | * notice, this list of conditions and the following disclaimer. | |
9 | * 2. Redistributions in binary form must reproduce the above copyright | |
10 | * notice, this list of conditions and the following disclaimer in the | |
11 | * documentation and/or other materials provided with the distribution. | |
12 | * | |
13 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
14 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
15 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
16 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
17 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
18 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
19 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
20 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
21 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
22 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
23 | */ | |
24 | ||
25 | #include "includes.h" | |
26 | #if OPENSSL_VERSION_NUMBER < 0x00907000L | |
540d72c3 | 27 | RCSID("$OpenBSD: cipher-aes.c,v 1.2 2003/11/26 21:44:29 djm Exp $"); |
c9307018 | 28 | |
29 | #include <openssl/evp.h> | |
30 | #include "rijndael.h" | |
31 | #include "xmalloc.h" | |
32 | #include "log.h" | |
33 | ||
ebcd87da | 34 | #if OPENSSL_VERSION_NUMBER < 0x00906000L |
35 | #define SSH_OLD_EVP | |
36 | #endif | |
37 | ||
c9307018 | 38 | #define RIJNDAEL_BLOCKSIZE 16 |
39 | struct ssh_rijndael_ctx | |
40 | { | |
41 | rijndael_ctx r_ctx; | |
42 | u_char r_iv[RIJNDAEL_BLOCKSIZE]; | |
43 | }; | |
44 | ||
45 | const EVP_CIPHER * evp_rijndael(void); | |
46 | void ssh_rijndael_iv(EVP_CIPHER_CTX *, int, u_char *, u_int); | |
47 | ||
48 | static int | |
49 | ssh_rijndael_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, | |
50 | int enc) | |
51 | { | |
52 | struct ssh_rijndael_ctx *c; | |
53 | ||
54 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | |
55 | c = xmalloc(sizeof(*c)); | |
56 | EVP_CIPHER_CTX_set_app_data(ctx, c); | |
57 | } | |
58 | if (key != NULL) { | |
59 | if (enc == -1) | |
60 | enc = ctx->encrypt; | |
61 | rijndael_set_key(&c->r_ctx, (u_char *)key, | |
62 | 8*EVP_CIPHER_CTX_key_length(ctx), enc); | |
63 | } | |
64 | if (iv != NULL) | |
65 | memcpy(c->r_iv, iv, RIJNDAEL_BLOCKSIZE); | |
66 | return (1); | |
67 | } | |
68 | ||
69 | static int | |
70 | ssh_rijndael_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, | |
71 | u_int len) | |
72 | { | |
73 | struct ssh_rijndael_ctx *c; | |
74 | u_char buf[RIJNDAEL_BLOCKSIZE]; | |
75 | u_char *cprev, *cnow, *plain, *ivp; | |
76 | int i, j, blocks = len / RIJNDAEL_BLOCKSIZE; | |
77 | ||
78 | if (len == 0) | |
79 | return (1); | |
80 | if (len % RIJNDAEL_BLOCKSIZE) | |
81 | fatal("ssh_rijndael_cbc: bad len %d", len); | |
82 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | |
83 | error("ssh_rijndael_cbc: no context"); | |
84 | return (0); | |
85 | } | |
86 | if (ctx->encrypt) { | |
87 | cnow = dest; | |
88 | plain = (u_char *)src; | |
89 | cprev = c->r_iv; | |
90 | for (i = 0; i < blocks; i++, plain+=RIJNDAEL_BLOCKSIZE, | |
91 | cnow+=RIJNDAEL_BLOCKSIZE) { | |
92 | for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++) | |
93 | buf[j] = plain[j] ^ cprev[j]; | |
94 | rijndael_encrypt(&c->r_ctx, buf, cnow); | |
95 | cprev = cnow; | |
96 | } | |
97 | memcpy(c->r_iv, cprev, RIJNDAEL_BLOCKSIZE); | |
98 | } else { | |
99 | cnow = (u_char *) (src+len-RIJNDAEL_BLOCKSIZE); | |
100 | plain = dest+len-RIJNDAEL_BLOCKSIZE; | |
101 | ||
102 | memcpy(buf, cnow, RIJNDAEL_BLOCKSIZE); | |
103 | for (i = blocks; i > 0; i--, cnow-=RIJNDAEL_BLOCKSIZE, | |
104 | plain-=RIJNDAEL_BLOCKSIZE) { | |
105 | rijndael_decrypt(&c->r_ctx, cnow, plain); | |
106 | ivp = (i == 1) ? c->r_iv : cnow-RIJNDAEL_BLOCKSIZE; | |
107 | for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++) | |
108 | plain[j] ^= ivp[j]; | |
109 | } | |
110 | memcpy(c->r_iv, buf, RIJNDAEL_BLOCKSIZE); | |
111 | } | |
112 | return (1); | |
113 | } | |
114 | ||
115 | static int | |
116 | ssh_rijndael_cleanup(EVP_CIPHER_CTX *ctx) | |
117 | { | |
118 | struct ssh_rijndael_ctx *c; | |
119 | ||
120 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) { | |
121 | memset(c, 0, sizeof(*c)); | |
122 | xfree(c); | |
123 | EVP_CIPHER_CTX_set_app_data(ctx, NULL); | |
124 | } | |
125 | return (1); | |
126 | } | |
127 | ||
128 | void | |
129 | ssh_rijndael_iv(EVP_CIPHER_CTX *evp, int doset, u_char * iv, u_int len) | |
130 | { | |
131 | struct ssh_rijndael_ctx *c; | |
132 | ||
133 | if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL) | |
134 | fatal("ssh_rijndael_iv: no context"); | |
135 | if (doset) | |
136 | memcpy(c->r_iv, iv, len); | |
137 | else | |
138 | memcpy(iv, c->r_iv, len); | |
139 | } | |
140 | ||
141 | const EVP_CIPHER * | |
142 | evp_rijndael(void) | |
143 | { | |
144 | static EVP_CIPHER rijndal_cbc; | |
145 | ||
146 | memset(&rijndal_cbc, 0, sizeof(EVP_CIPHER)); | |
147 | rijndal_cbc.nid = NID_undef; | |
148 | rijndal_cbc.block_size = RIJNDAEL_BLOCKSIZE; | |
149 | rijndal_cbc.iv_len = RIJNDAEL_BLOCKSIZE; | |
150 | rijndal_cbc.key_len = 16; | |
151 | rijndal_cbc.init = ssh_rijndael_init; | |
152 | rijndal_cbc.cleanup = ssh_rijndael_cleanup; | |
153 | rijndal_cbc.do_cipher = ssh_rijndael_cbc; | |
154 | #ifndef SSH_OLD_EVP | |
155 | rijndal_cbc.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH | | |
156 | EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CUSTOM_IV; | |
157 | #endif | |
158 | return (&rijndal_cbc); | |
159 | } | |
160 | #endif /* OPENSSL_VERSION_NUMBER */ |