Mercurial > dropbear

comparison libtomcrypt/src/modes/f8/f8_encrypt.c @ 382:0cbe8f6dbf9e

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 2af22fb4e878750b88f80f90d439b316d229796f) to branch 'au.asn.ucc.matt.dropbear' (head 02c413252c90e9de8e03d91e9939dde3029f5c0a)
author Matt Johnston <matt@ucc.asn.au>
date Thu, 11 Jan 2007 02:41:05 +0000
parents
children f849a5ca2efc
comparison
equal deleted inserted replaced
379:b66a00272a90 382:0cbe8f6dbf9e
1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
2 *
3 * LibTomCrypt is a library that provides various cryptographic
4 * algorithms in a highly modular and flexible manner.
5 *
6 * The library is free for all purposes without any express
7 * guarantee it works.
8 *
9 * Tom St Denis, [email protected], http://libtomcrypt.com
10 */
11 #include "tomcrypt.h"
12
13 /**
14 @file f8_encrypt.c
15 F8 implementation, encrypt data, Tom St Denis
16 */
17
18 #ifdef LTC_F8_MODE
19
20 /**
21 F8 encrypt
22 @param pt Plaintext
23 @param ct [out] Ciphertext
24 @param len Length of plaintext (octets)
25 @param f8 F8 state
26 @return CRYPT_OK if successful
27 */
28 int f8_encrypt(const unsigned char *pt, unsigned char *ct, unsigned long len, symmetric_F8 *f8)
29 {
30 int err, x;
31 unsigned char buf[MAXBLOCKSIZE];
32 LTC_ARGCHK(pt != NULL);
33 LTC_ARGCHK(ct != NULL);
34 LTC_ARGCHK(f8 != NULL);
35 if ((err = cipher_is_valid(f8->cipher)) != CRYPT_OK) {
36 return err;
37 }
38
39 /* is blocklen/padlen valid? */
40 if (f8->blocklen < 0 || f8->blocklen > (int)sizeof(f8->IV) ||
41 f8->padlen < 0 || f8->padlen > (int)sizeof(f8->IV)) {
42 return CRYPT_INVALID_ARG;
43 }
44
45 zeromem(buf, sizeof(buf));
46
47 /* make sure the pad is empty */
48 if (f8->padlen == f8->blocklen) {
49 /* xor of IV, MIV and blockcnt == what goes into cipher */
50 STORE32H(f8->blockcnt, (buf+(f8->blocklen-4)));
51 ++(f8->blockcnt);
52 for (x = 0; x < f8->blocklen; x++) {
53 f8->IV[x] ^= f8->MIV[x] ^ buf[x];
54 }
55 if ((err = cipher_descriptor[f8->cipher].ecb_encrypt(f8->IV, f8->IV, &f8->key)) != CRYPT_OK) {
56 return err;
57 }
58 f8->padlen = 0;
59 }
60
61 #ifdef LTC_FAST
62 if (f8->padlen == 0) {
63 while (len >= (unsigned long)f8->blocklen) {
64 STORE32H(f8->blockcnt, (buf+(f8->blocklen-4)));
65 ++(f8->blockcnt);
66 for (x = 0; x < f8->blocklen; x += sizeof(LTC_FAST_TYPE)) {
67 *((LTC_FAST_TYPE*)(&ct[x])) = *((LTC_FAST_TYPE*)(&pt[x])) ^ *((LTC_FAST_TYPE*)(&f8->IV[x]));
68 *((LTC_FAST_TYPE*)(&f8->IV[x])) ^= *((LTC_FAST_TYPE*)(&f8->MIV[x])) ^ *((LTC_FAST_TYPE*)(&buf[x]));
69 }
70 if ((err = cipher_descriptor[f8->cipher].ecb_encrypt(f8->IV, f8->IV, &f8->key)) != CRYPT_OK) {
71 return err;
72 }
73 len -= x;
74 pt += x;
75 ct += x;
76 }
77 }
78 #endif
79
80 while (len > 0) {
81 if (f8->padlen == f8->blocklen) {
82 /* xor of IV, MIV and blockcnt == what goes into cipher */
83 STORE32H(f8->blockcnt, (buf+(f8->blocklen-4)));
84 ++(f8->blockcnt);
85 for (x = 0; x < f8->blocklen; x++) {
86 f8->IV[x] ^= f8->MIV[x] ^ buf[x];
87 }
88 if ((err = cipher_descriptor[f8->cipher].ecb_encrypt(f8->IV, f8->IV, &f8->key)) != CRYPT_OK) {
89 return err;
90 }
91 f8->padlen = 0;
92 }
93 *ct++ = *pt++ ^ f8->IV[f8->padlen++];
94 --len;
95 }
96 return CRYPT_OK;
97 }
98
99 #endif
100
101 /* $Source: /cvs/libtom/libtomcrypt/src/modes/f8/f8_encrypt.c,v $ */
102 /* $Revision: 1.6 $ */
103 /* $Date: 2006/11/05 04:16:32 $ */