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1 | /* |
2 | * Blowfish |
3 | * |
4 | * arguments: key size in bits (must be multiple of 8) |
5 | * |
6 | * key values: 8 byte random IV and n byte random key |
7 | * |
8 | * encoding: do CBC encryption overwriting message |
9 | * encoding for MAC: do CBC and prepend last ciphertext block |
10 | */ |
11 | |
aaa9ab3a |
12 | #include "forwarder.h" |
84f87e82 |
13 | #include "blowfish.h" |
14 | |
15 | struct mechdata { |
16 | struct blowfish_cbc_state cbc; |
17 | }; |
18 | |
19 | static void mds_blowfish(struct mechdata **md_r) { |
20 | struct mechdata *md; |
21 | unsigned long keysize; |
22 | unsigned char iv[BLOWFISH_BLOCKBYTES]; |
23 | unsigned char key[BLOWFISH_MAXKEYBYTES]; |
24 | |
25 | md= xmalloc(sizeof(md)); |
26 | |
27 | keysize= getarg_ulong(); |
28 | arg_assert(!(keysize & 7)); |
29 | keysize >>= 3; |
30 | arg_assert(keysize > 0 && keysize <= BLOWFISH_MAXKEYBYTES); |
31 | |
32 | random_key(iv,sizeof(iv)); |
33 | random_key(key,keysize); |
34 | |
35 | blowfish_loadkey(&md->cbc.ek, key,keysize); |
36 | blowfish_cbc_setiv(&md->cbc, iv); |
37 | |
38 | *md_r= md; |
39 | } |
40 | |
41 | static void mes_blowfish(struct mechdata **md_r, int *maxprefix_io, int *maxsuffix_io) { |
42 | mds_blowfish(md_r); |
43 | } |
44 | |
45 | static void mds_bfmac(struct mechdata **md_r) { |
46 | mds_blowfish(md_r); |
47 | } |
48 | |
49 | static void mes_bfmac(struct mechdata **md_r, int *maxprefix_io, int *maxsuffix_io) { |
50 | mds_blowfish(md_r); |
51 | *maxprefix_io += BLOWFISH_BLOCKBYTES; |
52 | } |
53 | |
54 | #define MSGSIZE_OUT \ |
55 | msgsize= buf->size; \ |
56 | arg_assert(!(msgsize & ~BLOWFISH_BLOCKBYTES)); |
57 | |
58 | #define MSGSIZE_IN \ |
59 | msgsize= buf->size; \ |
60 | if (msgsize & ~BLOWFISH_BLOCKBYTES) return "not multiple of block size" |
61 | |
62 | #define FOREACH_BLOCK(func,inptr,outptr) \ |
63 | { \ |
64 | unsigned char *ptr; \ |
65 | ptr= buf->start; \ |
66 | while (ptr < buf->start + msgsize) \ |
67 | func(&md->cbc,inptr,outptr); \ |
68 | } |
69 | |
70 | static void menc_blowfish(struct mechdata *md, struct buffer *buf) { |
71 | unsigned long msgsize; |
72 | MSGSIZE_OUT; |
73 | FOREACH_BLOCK(blowfish_cbc_encrypt,ptr,ptr); |
74 | } |
75 | |
76 | static const char *mdec_blowfish(struct mechdata *md, struct buffer *buf) { |
77 | unsigned long msgsize; |
78 | MSGSIZE_IN; |
79 | FOREACH_BLOCK(blowfish_cbc_decrypt,ptr,ptr); |
80 | return 0; |
81 | } |
82 | |
83 | static void menc_bfmac(struct mechdata *md, struct buffer *buf) { |
84 | unsigned long msgsize; |
85 | unsigned char outblock[BLOWFISH_BLOCKBYTES]; |
86 | |
87 | MSGSIZE_OUT; |
88 | FOREACH_BLOCK(blowfish_cbc_encrypt,ptr,outblock); |
89 | memcpy(buf_prepend(buf,BLOWFISH_BLOCKBYTES), outblock, BLOWFISH_BLOCKBYTES); |
90 | } |
91 | |
92 | static const char *mdec_bfmac(struct mechdata *md, struct buffer *buf) { |
93 | unsigned long msgsize; |
94 | unsigned char outblock[BLOWFISH_BLOCKBYTES]; |
95 | unsigned char *checkblock; |
96 | |
97 | BUF_UNPREPEND(checkblock,buf,BLOWFISH_BLOCKBYTES); |
98 | MSGSIZE_IN; |
99 | FOREACH_BLOCK(blowfish_cbc_encrypt,ptr,outblock); |
100 | if (memcmp(checkblock,outblock,BLOWFISH_BLOCKBYTES)) return "verify failed"; |
101 | return 0; |
102 | } |
103 | |
104 | const struct mechanism mechlist_blowfish[]= { |
105 | STANDARD_MECHANISM("blowfish-cbcmac", bfmac) |
106 | STANDARD_MECHANISM("blowfish-cbc", blowfish) |
107 | { 0 } |
108 | }; |