Commit | Line | Data |
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1fb3cba0 | 1 | /* |
f0e54a99 | 2 | * Blowfish mechanism for udp tunnel |
1fb3cba0 | 3 | * |
5124214b | 4 | * mechanisms: blowfish-cbc, blowfish-cbcmac |
1fb3cba0 | 5 | * arguments: key size in bits (must be multiple of 8) |
6 | * | |
7 | * key values: 8 byte random IV and n byte random key | |
8 | * | |
5124214b | 9 | * restrictions: plaintext length must be multiple of block size (8 bytes) |
1fb3cba0 | 10 | * encoding: do CBC encryption overwriting message |
11 | * encoding for MAC: do CBC and prepend last ciphertext block | |
12 | */ | |
f0e54a99 | 13 | /* |
c07be359 | 14 | * This file is part of ipif, part of userv-utils |
f0e54a99 | 15 | * |
9028e234 IJ |
16 | * Copyright 1996-2013 Ian Jackson <ijackson@chiark.greenend.org.uk> |
17 | * Copyright 1998 David Damerell <damerell@chiark.greenend.org.uk> | |
18 | * Copyright 1999,2003 | |
19 | * Chancellor Masters and Scholars of the University of Cambridge | |
20 | * Copyright 2010 Tony Finch <fanf@dotat.at> | |
21 | * | |
f0e54a99 | 22 | * This is free software; you can redistribute it and/or modify it |
23 | * under the terms of the GNU General Public License as published by | |
9028e234 | 24 | * the Free Software Foundation; either version 3 of the License, or |
f0e54a99 | 25 | * (at your option) any later version. |
26 | * | |
27 | * This program is distributed in the hope that it will be useful, but | |
28 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
29 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
30 | * General Public License for more details. | |
31 | * | |
32 | * You should have received a copy of the GNU General Public License | |
9028e234 | 33 | * along with userv-utils; if not, see http://www.gnu.org/licenses/. |
f0e54a99 | 34 | */ |
1fb3cba0 | 35 | |
f9e59051 | 36 | #include "forwarder.h" |
1fb3cba0 | 37 | #include "blowfish.h" |
38 | ||
39 | struct mechdata { | |
ed509ebd | 40 | unsigned char iv[BLOWFISH_BLOCKBYTES]; |
1fb3cba0 | 41 | struct blowfish_cbc_state cbc; |
42 | }; | |
43 | ||
44 | static void mds_blowfish(struct mechdata **md_r) { | |
45 | struct mechdata *md; | |
46 | unsigned long keysize; | |
1fb3cba0 | 47 | unsigned char key[BLOWFISH_MAXKEYBYTES]; |
48 | ||
0f4b558c | 49 | XMALLOC(md); |
1fb3cba0 | 50 | |
51 | keysize= getarg_ulong(); | |
52 | arg_assert(!(keysize & 7)); | |
53 | keysize >>= 3; | |
54 | arg_assert(keysize > 0 && keysize <= BLOWFISH_MAXKEYBYTES); | |
55 | ||
ed509ebd | 56 | random_key(md->iv,sizeof(md->iv)); |
1fb3cba0 | 57 | random_key(key,keysize); |
58 | ||
59 | blowfish_loadkey(&md->cbc.ek, key,keysize); | |
1fb3cba0 | 60 | *md_r= md; |
61 | } | |
62 | ||
63 | static void mes_blowfish(struct mechdata **md_r, int *maxprefix_io, int *maxsuffix_io) { | |
64 | mds_blowfish(md_r); | |
65 | } | |
66 | ||
67 | static void mds_bfmac(struct mechdata **md_r) { | |
68 | mds_blowfish(md_r); | |
69 | } | |
70 | ||
71 | static void mes_bfmac(struct mechdata **md_r, int *maxprefix_io, int *maxsuffix_io) { | |
72 | mds_blowfish(md_r); | |
73 | *maxprefix_io += BLOWFISH_BLOCKBYTES; | |
74 | } | |
75 | ||
76 | #define MSGSIZE_OUT \ | |
77 | msgsize= buf->size; \ | |
0f4b558c | 78 | arg_assert(!(msgsize & (BLOWFISH_BLOCKBYTES-1))); |
1fb3cba0 | 79 | |
80 | #define MSGSIZE_IN \ | |
81 | msgsize= buf->size; \ | |
0f4b558c | 82 | if (msgsize & (BLOWFISH_BLOCKBYTES-1)) return "not multiple of block size" |
1fb3cba0 | 83 | |
84 | #define FOREACH_BLOCK(func,inptr,outptr) \ | |
85 | { \ | |
86 | unsigned char *ptr; \ | |
ed509ebd | 87 | blowfish_cbc_setiv(&md->cbc, md->iv); \ |
0f4b558c | 88 | for (ptr= buf->start; \ |
89 | ptr < buf->start + msgsize; \ | |
90 | ptr += BLOWFISH_BLOCKBYTES) { \ | |
1fb3cba0 | 91 | func(&md->cbc,inptr,outptr); \ |
0f4b558c | 92 | } \ |
1fb3cba0 | 93 | } |
94 | ||
95 | static void menc_blowfish(struct mechdata *md, struct buffer *buf) { | |
96 | unsigned long msgsize; | |
97 | MSGSIZE_OUT; | |
98 | FOREACH_BLOCK(blowfish_cbc_encrypt,ptr,ptr); | |
99 | } | |
100 | ||
101 | static const char *mdec_blowfish(struct mechdata *md, struct buffer *buf) { | |
102 | unsigned long msgsize; | |
103 | MSGSIZE_IN; | |
104 | FOREACH_BLOCK(blowfish_cbc_decrypt,ptr,ptr); | |
105 | return 0; | |
106 | } | |
107 | ||
108 | static void menc_bfmac(struct mechdata *md, struct buffer *buf) { | |
109 | unsigned long msgsize; | |
110 | unsigned char outblock[BLOWFISH_BLOCKBYTES]; | |
111 | ||
112 | MSGSIZE_OUT; | |
113 | FOREACH_BLOCK(blowfish_cbc_encrypt,ptr,outblock); | |
114 | memcpy(buf_prepend(buf,BLOWFISH_BLOCKBYTES), outblock, BLOWFISH_BLOCKBYTES); | |
115 | } | |
116 | ||
117 | static const char *mdec_bfmac(struct mechdata *md, struct buffer *buf) { | |
118 | unsigned long msgsize; | |
119 | unsigned char outblock[BLOWFISH_BLOCKBYTES]; | |
120 | unsigned char *checkblock; | |
121 | ||
122 | BUF_UNPREPEND(checkblock,buf,BLOWFISH_BLOCKBYTES); | |
123 | MSGSIZE_IN; | |
124 | FOREACH_BLOCK(blowfish_cbc_encrypt,ptr,outblock); | |
125 | if (memcmp(checkblock,outblock,BLOWFISH_BLOCKBYTES)) return "verify failed"; | |
126 | return 0; | |
127 | } | |
128 | ||
129 | const struct mechanism mechlist_blowfish[]= { | |
130 | STANDARD_MECHANISM("blowfish-cbcmac", bfmac) | |
131 | STANDARD_MECHANISM("blowfish-cbc", blowfish) | |
132 | { 0 } | |
133 | }; |