| 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 | |
| 12 | #include "forwarder.h" |
| 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 | }; |