1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
|
/* LibTomCrypt, modular cryptographic library -- Tom St Denis
*
* LibTomCrypt is a library that provides various cryptographic
* algorithms in a highly modular and flexible manner.
*
* The library is free for all purposes without any express
* guarantee it works.
*
* Tom St Denis, tomstdenis@gmail.com, http://libtom.org
*/
/**
@file gcm_memory.c
GCM implementation, process a packet, by Tom St Denis
*/
#include "tomcrypt.h"
#ifdef LTC_GCM_MODE
/**
Process an entire GCM packet in one call.
@param cipher Index of cipher to use
@param key The secret key
@param keylen The length of the secret key
@param IV The initial vector
@param IVlen The length of the initial vector
@param adata The additional authentication data (header)
@param adatalen The length of the adata
@param pt The plaintext
@param ptlen The length of the plaintext (ciphertext length is the same)
@param ct The ciphertext
@param tag [out] The MAC tag
@param taglen [in/out] The MAC tag length
@param direction Encrypt or Decrypt mode (GCM_ENCRYPT or GCM_DECRYPT)
@return CRYPT_OK on success
*/
int gcm_memory( int cipher,
const unsigned char *key, unsigned long keylen,
const unsigned char *IV, unsigned long IVlen,
const unsigned char *adata, unsigned long adatalen,
unsigned char *pt, unsigned long ptlen,
unsigned char *ct,
unsigned char *tag, unsigned long *taglen,
int direction)
{
void *orig;
gcm_state *gcm;
int err;
if ((err = cipher_is_valid(cipher)) != CRYPT_OK) {
return err;
}
if (cipher_descriptor[cipher].accel_gcm_memory != NULL) {
return
cipher_descriptor[cipher].accel_gcm_memory
(key, keylen,
IV, IVlen,
adata, adatalen,
pt, ptlen,
ct,
tag, taglen,
direction);
}
#ifndef LTC_GCM_TABLES_SSE2
orig = gcm = XMALLOC(sizeof(*gcm));
#else
orig = gcm = XMALLOC(sizeof(*gcm) + 16);
#endif
if (gcm == NULL) {
return CRYPT_MEM;
}
/* Force GCM to be on a multiple of 16 so we can use 128-bit aligned operations
* note that we only modify gcm and keep orig intact. This code is not portable
* but again it's only for SSE2 anyways, so who cares?
*/
#ifdef LTC_GCM_TABLES_SSE2
if ((unsigned long)gcm & 15) {
gcm = (gcm_state *)((unsigned long)gcm + (16 - ((unsigned long)gcm & 15)));
}
#endif
if ((err = gcm_init(gcm, cipher, key, keylen)) != CRYPT_OK) {
goto LTC_ERR;
}
if ((err = gcm_add_iv(gcm, IV, IVlen)) != CRYPT_OK) {
goto LTC_ERR;
}
if ((err = gcm_add_aad(gcm, adata, adatalen)) != CRYPT_OK) {
goto LTC_ERR;
}
if ((err = gcm_process(gcm, pt, ptlen, ct, direction)) != CRYPT_OK) {
goto LTC_ERR;
}
err = gcm_done(gcm, tag, taglen);
LTC_ERR:
XFREE(orig);
return err;
}
#endif
/* $Source$ */
/* $Revision$ */
/* $Date$ */
|
