2 * Blowfish mechanism for udp tunnel
4 * arguments: key size in bits (must be multiple of 8)
6 * key values: 8 byte random IV and n byte random key
8 * encoding: do CBC encryption overwriting message
9 * encoding for MAC: do CBC and prepend last ciphertext block
12 * Copyright (C) 2000 Ian Jackson
14 * This is free software; you can redistribute it and/or modify it
15 * under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * This program is distributed in the hope that it will be useful, but
20 * WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 * General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with userv-utils; if not, write to the Free Software
26 * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
29 #include "forwarder.h"
33 unsigned char iv
[BLOWFISH_BLOCKBYTES
];
34 struct blowfish_cbc_state cbc
;
37 static void mds_blowfish(struct mechdata
**md_r
) {
39 unsigned long keysize
;
40 unsigned char key
[BLOWFISH_MAXKEYBYTES
];
44 keysize
= getarg_ulong();
45 arg_assert(!(keysize
& 7));
47 arg_assert(keysize
> 0 && keysize
<= BLOWFISH_MAXKEYBYTES
);
49 random_key(md
->iv
,sizeof(md
->iv
));
50 random_key(key
,keysize
);
52 blowfish_loadkey(&md
->cbc
.ek
, key
,keysize
);
56 static void mes_blowfish(struct mechdata
**md_r
, int *maxprefix_io
, int *maxsuffix_io
) {
60 static void mds_bfmac(struct mechdata
**md_r
) {
64 static void mes_bfmac(struct mechdata
**md_r
, int *maxprefix_io
, int *maxsuffix_io
) {
66 *maxprefix_io
+= BLOWFISH_BLOCKBYTES
;
71 arg_assert(!(msgsize & (BLOWFISH_BLOCKBYTES-1)));
75 if (msgsize & (BLOWFISH_BLOCKBYTES-1)) return "not multiple of block size"
77 #define FOREACH_BLOCK(func,inptr,outptr) \
80 blowfish_cbc_setiv(&md->cbc, md->iv); \
81 for (ptr= buf->start; \
82 ptr < buf->start + msgsize; \
83 ptr += BLOWFISH_BLOCKBYTES) { \
84 func(&md->cbc,inptr,outptr); \
88 static void menc_blowfish(struct mechdata
*md
, struct buffer
*buf
) {
89 unsigned long msgsize
;
91 FOREACH_BLOCK(blowfish_cbc_encrypt
,ptr
,ptr
);
94 static const char *mdec_blowfish(struct mechdata
*md
, struct buffer
*buf
) {
95 unsigned long msgsize
;
97 FOREACH_BLOCK(blowfish_cbc_decrypt
,ptr
,ptr
);
101 static void menc_bfmac(struct mechdata
*md
, struct buffer
*buf
) {
102 unsigned long msgsize
;
103 unsigned char outblock
[BLOWFISH_BLOCKBYTES
];
106 FOREACH_BLOCK(blowfish_cbc_encrypt
,ptr
,outblock
);
107 memcpy(buf_prepend(buf
,BLOWFISH_BLOCKBYTES
), outblock
, BLOWFISH_BLOCKBYTES
);
110 static const char *mdec_bfmac(struct mechdata
*md
, struct buffer
*buf
) {
111 unsigned long msgsize
;
112 unsigned char outblock
[BLOWFISH_BLOCKBYTES
];
113 unsigned char *checkblock
;
115 BUF_UNPREPEND(checkblock
,buf
,BLOWFISH_BLOCKBYTES
);
117 FOREACH_BLOCK(blowfish_cbc_encrypt
,ptr
,outblock
);
118 if (memcmp(checkblock
,outblock
,BLOWFISH_BLOCKBYTES
)) return "verify failed";
122 const struct mechanism mechlist_blowfish
[]= {
123 STANDARD_MECHANISM("blowfish-cbcmac", bfmac
)
124 STANDARD_MECHANISM("blowfish-cbc", blowfish
)