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
27 /* compatibility with old or broken OpenSSL versions */
28 #include "openbsd-compat/openssl-compat.h"
29
30 #ifdef USE_BUILTIN_RIJNDAEL
31 #include <sys/types.h>
32
33 #include <openssl/evp.h>
34
35 #include <stdarg.h>
36 #include <string.h>
37
38 #include "rijndael.h"
39 #include "xmalloc.h"
40 #include "log.h"
41
42 #define RIJNDAEL_BLOCKSIZE 16
43 struct ssh_rijndael_ctx
44 {
45 rijndael_ctx r_ctx;
46 u_char r_iv[RIJNDAEL_BLOCKSIZE];
47 };
48
49 const EVP_CIPHER * evp_rijndael(void);
50 void ssh_rijndael_iv(EVP_CIPHER_CTX *, int, u_char *, u_int);
51
52 static int
ssh_rijndael_init(EVP_CIPHER_CTX * ctx,const u_char * key,const u_char * iv,int enc)53 ssh_rijndael_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv,
54 int enc)
55 {
56 struct ssh_rijndael_ctx *c;
57
58 if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
59 c = xmalloc(sizeof(*c));
60 EVP_CIPHER_CTX_set_app_data(ctx, c);
61 }
62 if (key != NULL) {
63 if (enc == -1)
64 enc = ctx->encrypt;
65 rijndael_set_key(&c->r_ctx, (u_char *)key,
66 8*EVP_CIPHER_CTX_key_length(ctx), enc);
67 }
68 if (iv != NULL)
69 memcpy(c->r_iv, iv, RIJNDAEL_BLOCKSIZE);
70 return (1);
71 }
72
73 static int
ssh_rijndael_cbc(EVP_CIPHER_CTX * ctx,u_char * dest,const u_char * src,LIBCRYPTO_EVP_INL_TYPE len)74 ssh_rijndael_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src,
75 LIBCRYPTO_EVP_INL_TYPE len)
76 {
77 struct ssh_rijndael_ctx *c;
78 u_char buf[RIJNDAEL_BLOCKSIZE];
79 u_char *cprev, *cnow, *plain, *ivp;
80 int i, j, blocks = len / RIJNDAEL_BLOCKSIZE;
81
82 if (len == 0)
83 return (1);
84 if (len % RIJNDAEL_BLOCKSIZE)
85 fatal("ssh_rijndael_cbc: bad len %d", len);
86 if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
87 error("ssh_rijndael_cbc: no context");
88 return (0);
89 }
90 if (ctx->encrypt) {
91 cnow = dest;
92 plain = (u_char *)src;
93 cprev = c->r_iv;
94 for (i = 0; i < blocks; i++, plain+=RIJNDAEL_BLOCKSIZE,
95 cnow+=RIJNDAEL_BLOCKSIZE) {
96 for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++)
97 buf[j] = plain[j] ^ cprev[j];
98 rijndael_encrypt(&c->r_ctx, buf, cnow);
99 cprev = cnow;
100 }
101 memcpy(c->r_iv, cprev, RIJNDAEL_BLOCKSIZE);
102 } else {
103 cnow = (u_char *) (src+len-RIJNDAEL_BLOCKSIZE);
104 plain = dest+len-RIJNDAEL_BLOCKSIZE;
105
106 memcpy(buf, cnow, RIJNDAEL_BLOCKSIZE);
107 for (i = blocks; i > 0; i--, cnow-=RIJNDAEL_BLOCKSIZE,
108 plain-=RIJNDAEL_BLOCKSIZE) {
109 rijndael_decrypt(&c->r_ctx, cnow, plain);
110 ivp = (i == 1) ? c->r_iv : cnow-RIJNDAEL_BLOCKSIZE;
111 for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++)
112 plain[j] ^= ivp[j];
113 }
114 memcpy(c->r_iv, buf, RIJNDAEL_BLOCKSIZE);
115 }
116 return (1);
117 }
118
119 static int
ssh_rijndael_cleanup(EVP_CIPHER_CTX * ctx)120 ssh_rijndael_cleanup(EVP_CIPHER_CTX *ctx)
121 {
122 struct ssh_rijndael_ctx *c;
123
124 if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) {
125 memset(c, 0, sizeof(*c));
126 xfree(c);
127 EVP_CIPHER_CTX_set_app_data(ctx, NULL);
128 }
129 return (1);
130 }
131
132 void
ssh_rijndael_iv(EVP_CIPHER_CTX * evp,int doset,u_char * iv,u_int len)133 ssh_rijndael_iv(EVP_CIPHER_CTX *evp, int doset, u_char * iv, u_int len)
134 {
135 struct ssh_rijndael_ctx *c;
136
137 if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL)
138 fatal("ssh_rijndael_iv: no context");
139 if (doset)
140 memcpy(c->r_iv, iv, len);
141 else
142 memcpy(iv, c->r_iv, len);
143 }
144
145 const EVP_CIPHER *
evp_rijndael(void)146 evp_rijndael(void)
147 {
148 static EVP_CIPHER rijndal_cbc;
149
150 memset(&rijndal_cbc, 0, sizeof(EVP_CIPHER));
151 rijndal_cbc.nid = NID_undef;
152 rijndal_cbc.block_size = RIJNDAEL_BLOCKSIZE;
153 rijndal_cbc.iv_len = RIJNDAEL_BLOCKSIZE;
154 rijndal_cbc.key_len = 16;
155 rijndal_cbc.init = ssh_rijndael_init;
156 rijndal_cbc.cleanup = ssh_rijndael_cleanup;
157 rijndal_cbc.do_cipher = ssh_rijndael_cbc;
158 #ifndef SSH_OLD_EVP
159 rijndal_cbc.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH |
160 EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CUSTOM_IV;
161 #endif
162 return (&rijndal_cbc);
163 }
164 #endif /* USE_BUILTIN_RIJNDAEL */
165