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comparison src/mac/pelican/pelican.c @ 192:9cc34777b479 libtomcrypt

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propagate from branch 'au.asn.ucc.matt.ltc-orig' (head 9ba8f01f44320e9cb9f19881105ae84f84a43ea9) to branch 'au.asn.ucc.matt.dropbear.ltc' (head dbf51c569bc34956ad948e4cc87a0eeb2170b768)
author Matt Johnston <matt@ucc.asn.au>
date Sun, 08 May 2005 06:36:47 +0000
parents 1c15b283127b
children 39d5d58461d6
comparison
equal deleted inserted replaced
164:cd1143579f00 192:9cc34777b479
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.org
10 */
11 #include "tomcrypt.h"
12
13 /**
14 @file pelican.c
15 Pelican MAC, initialize state, by Tom St Denis
16 */
17
18 #ifdef PELICAN
19
20 #define ENCRYPT_ONLY
21 #include "../../ciphers/aes/aes_tab.c"
22
23
24 /**
25 Initialize a Pelican state
26 @param pelmac The Pelican state to initialize
27 @param key The secret key
28 @param keylen The length of the secret key (octets)
29 @return CRYPT_OK if successful
30 */
31 int pelican_init(pelican_state *pelmac, const unsigned char *key, unsigned long keylen)
32 {
33 int err;
34
35 LTC_ARGCHK(pelmac != NULL);
36 LTC_ARGCHK(key != NULL);
37
38 #ifdef LTC_FAST
39 if (16 % sizeof(LTC_FAST_TYPE)) {
40 return CRYPT_INVALID_ARG;
41 }
42 #endif
43
44 if ((err = aes_setup(key, keylen, 0, &pelmac->K)) != CRYPT_OK) {
45 return err;
46 }
47
48 zeromem(pelmac->state, 16);
49 aes_ecb_encrypt(pelmac->state, pelmac->state, &pelmac->K);
50 pelmac->buflen = 0;
51
52 return CRYPT_OK;
53 }
54
55 static void four_rounds(pelican_state *pelmac)
56 {
57 ulong32 s0, s1, s2, s3, t0, t1, t2, t3;
58 int r;
59
60 LOAD32H(s0, pelmac->state );
61 LOAD32H(s1, pelmac->state + 4);
62 LOAD32H(s2, pelmac->state + 8);
63 LOAD32H(s3, pelmac->state + 12);
64 for (r = 0; r < 4; r++) {
65 t0 =
66 Te0(byte(s0, 3)) ^
67 Te1(byte(s1, 2)) ^
68 Te2(byte(s2, 1)) ^
69 Te3(byte(s3, 0));
70 t1 =
71 Te0(byte(s1, 3)) ^
72 Te1(byte(s2, 2)) ^
73 Te2(byte(s3, 1)) ^
74 Te3(byte(s0, 0));
75 t2 =
76 Te0(byte(s2, 3)) ^
77 Te1(byte(s3, 2)) ^
78 Te2(byte(s0, 1)) ^
79 Te3(byte(s1, 0));
80 t3 =
81 Te0(byte(s3, 3)) ^
82 Te1(byte(s0, 2)) ^
83 Te2(byte(s1, 1)) ^
84 Te3(byte(s2, 0));
85 s0 = t0; s1 = t1; s2 = t2; s3 = t3;
86 }
87 STORE32H(s0, pelmac->state );
88 STORE32H(s1, pelmac->state + 4);
89 STORE32H(s2, pelmac->state + 8);
90 STORE32H(s3, pelmac->state + 12);
91 }
92
93 /**
94 Process a block of text through Pelican
95 @param pelmac The Pelican MAC state
96 @param in The input
97 @param inlen The length input (octets)
98 @return CRYPT_OK on success
99 */
100 int pelican_process(pelican_state *pelmac, const unsigned char *in, unsigned long inlen)
101 {
102
103 LTC_ARGCHK(pelmac != NULL);
104 LTC_ARGCHK(in != NULL);
105 #ifdef LTC_FAST
106 if (pelmac->buflen == 0) {
107 while (inlen & ~15) {
108 int x;
109 for (x = 0; x < 16; x += sizeof(LTC_FAST_TYPE)) {
110 *((LTC_FAST_TYPE*)((unsigned char *)pelmac->state + x)) ^= *((LTC_FAST_TYPE*)((unsigned char *)in + x));
111 }
112 four_rounds(pelmac);
113 in += 16;
114 inlen -= 16;
115 }
116 }
117 #endif
118
119 while (inlen--) {
120 pelmac->state[pelmac->buflen++] ^= *in++;
121 if (pelmac->buflen == 16) {
122 four_rounds(pelmac);
123 pelmac->buflen = 0;
124 }
125 }
126 return CRYPT_OK;
127 }
128
129 /**
130 Terminate Pelican MAC
131 @param pelmac The Pelican MAC state
132 @param out [out] The TAG
133 @return CRYPT_OK on sucess
134 */
135 int pelican_done(pelican_state *pelmac, unsigned char *out)
136 {
137 LTC_ARGCHK(pelmac != NULL);
138 LTC_ARGCHK(out != NULL);
139 if (pelmac->buflen == 16) {
140 four_rounds(pelmac);
141 pelmac->buflen = 0;
142 }
143 pelmac->state[pelmac->buflen++] ^= 0x80;
144 aes_ecb_encrypt(pelmac->state, out, &pelmac->K);
145 aes_done(&pelmac->K);
146 return CRYPT_OK;
147 }
148
149 #endif