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comparison libtomcrypt/src/modes/f8/f8_start.c @ 1471:6dba84798cd5

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Update to libtomcrypt 1.18.1, merged with Dropbear changes
author Matt Johnston <matt@ucc.asn.au>
date Fri, 09 Feb 2018 21:44:05 +0800
parents f849a5ca2efc
children
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1470:8bba51a55704 1471:6dba84798cd5
3 * LibTomCrypt is a library that provides various cryptographic 3 * LibTomCrypt is a library that provides various cryptographic
4 * algorithms in a highly modular and flexible manner. 4 * algorithms in a highly modular and flexible manner.
5 * 5 *
6 * The library is free for all purposes without any express 6 * The library is free for all purposes without any express
7 * guarantee it works. 7 * guarantee it works.
8 *
9 * Tom St Denis, [email protected], http://libtom.org
10 */ 8 */
11 #include "tomcrypt.h" 9 #include "tomcrypt.h"
12 10
13 /** 11 /**
14 @file f8_start.c 12 @file f8_start.c
19 #ifdef LTC_F8_MODE 17 #ifdef LTC_F8_MODE
20 18
21 /** 19 /**
22 Initialize an F8 context 20 Initialize an F8 context
23 @param cipher The index of the cipher desired 21 @param cipher The index of the cipher desired
24 @param IV The initial vector 22 @param IV The initialization vector
25 @param key The secret key 23 @param key The secret key
26 @param keylen The length of the secret key (octets) 24 @param keylen The length of the secret key (octets)
27 @param salt_key The salting key for the IV 25 @param salt_key The salting key for the IV
28 @param skeylen The length of the salting key (octets) 26 @param skeylen The length of the salting key (octets)
29 @param num_rounds Number of rounds in the cipher desired (0 for default) 27 @param num_rounds Number of rounds in the cipher desired (0 for default)
30 @param f8 The F8 state to initialize 28 @param f8 The F8 state to initialize
31 @return CRYPT_OK if successful 29 @return CRYPT_OK if successful
32 */ 30 */
33 int f8_start( int cipher, const unsigned char *IV, 31 int f8_start( int cipher, const unsigned char *IV,
34 const unsigned char *key, int keylen, 32 const unsigned char *key, int keylen,
35 const unsigned char *salt_key, int skeylen, 33 const unsigned char *salt_key, int skeylen,
36 int num_rounds, symmetric_F8 *f8) 34 int num_rounds, symmetric_F8 *f8)
37 { 35 {
38 int x, err; 36 int x, err;
39 unsigned char tkey[MAXBLOCKSIZE]; 37 unsigned char tkey[MAXBLOCKSIZE];
56 /* copy details */ 54 /* copy details */
57 f8->blockcnt = 0; 55 f8->blockcnt = 0;
58 f8->cipher = cipher; 56 f8->cipher = cipher;
59 f8->blocklen = cipher_descriptor[cipher].block_length; 57 f8->blocklen = cipher_descriptor[cipher].block_length;
60 f8->padlen = f8->blocklen; 58 f8->padlen = f8->blocklen;
61 59
62 /* now get key ^ salt_key [extend salt_ket with 0x55 as required to match length] */ 60 /* now get key ^ salt_key [extend salt_ket with 0x55 as required to match length] */
63 zeromem(tkey, sizeof(tkey)); 61 zeromem(tkey, sizeof(tkey));
64 for (x = 0; x < keylen && x < (int)sizeof(tkey); x++) { 62 for (x = 0; x < keylen && x < (int)sizeof(tkey); x++) {
65 tkey[x] = key[x]; 63 tkey[x] = key[x];
66 } 64 }
67 for (x = 0; x < skeylen && x < (int)sizeof(tkey); x++) { 65 for (x = 0; x < skeylen && x < (int)sizeof(tkey); x++) {
68 tkey[x] ^= salt_key[x]; 66 tkey[x] ^= salt_key[x];
69 } 67 }
70 for (; x < keylen && x < (int)sizeof(tkey); x++) { 68 for (; x < keylen && x < (int)sizeof(tkey); x++) {
71 tkey[x] ^= 0x55; 69 tkey[x] ^= 0x55;
72 } 70 }
73 71
74 /* now encrypt with tkey[0..keylen-1] the IV and use that as the IV */ 72 /* now encrypt with tkey[0..keylen-1] the IV and use that as the IV */
75 if ((err = cipher_descriptor[cipher].setup(tkey, keylen, num_rounds, &f8->key)) != CRYPT_OK) { 73 if ((err = cipher_descriptor[cipher].setup(tkey, keylen, num_rounds, &f8->key)) != CRYPT_OK) {
76 return err; 74 return err;
77 } 75 }
78 76
79 /* encrypt IV */ 77 /* encrypt IV */
80 if ((err = cipher_descriptor[f8->cipher].ecb_encrypt(IV, f8->MIV, &f8->key)) != CRYPT_OK) { 78 if ((err = cipher_descriptor[f8->cipher].ecb_encrypt(IV, f8->MIV, &f8->key)) != CRYPT_OK) {
81 cipher_descriptor[f8->cipher].done(&f8->key); 79 cipher_descriptor[f8->cipher].done(&f8->key);
82 return err; 80 return err;
83 } 81 }
84 zeromem(tkey, sizeof(tkey)); 82 zeromem(tkey, sizeof(tkey));
85 zeromem(f8->IV, sizeof(f8->IV)); 83 zeromem(f8->IV, sizeof(f8->IV));
86 84
87 /* terminate this cipher */ 85 /* terminate this cipher */
88 cipher_descriptor[f8->cipher].done(&f8->key); 86 cipher_descriptor[f8->cipher].done(&f8->key);
89 87
90 /* init the cipher */ 88 /* init the cipher */
91 return cipher_descriptor[cipher].setup(key, keylen, num_rounds, &f8->key); 89 return cipher_descriptor[cipher].setup(key, keylen, num_rounds, &f8->key);
92 } 90 }
93 91
94 #endif 92 #endif
95 93
96 /* $Source$ */ 94 /* ref: $Format:%D$ */
97 /* $Revision$ */ 95 /* git commit: $Format:%H$ */
98 /* $Date$ */ 96 /* commit time: $Format:%ai$ */