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, tomstdenis@gmail.com, http://libtomcrypt.com
10 */
11 #include "tomcrypt.h"
12
13 /**
14 @file xcbc_file.c
15 XCBC support, process a file, Tom St Denis
16 */
17
18 #ifdef LTC_XCBC
19
20 /**
21 XCBC a file
22 @param cipher The index of the cipher desired
23 @param key The secret key
24 @param keylen The length of the secret key (octets)
25 @param filename The name of the file you wish to XCBC
26 @param out [out] Where the authentication tag is to be stored
27 @param outlen [in/out] The max size and resulting size of the authentication tag
28 @return CRYPT_OK if successful, CRYPT_NOP if file support has been disabled
29 */
xcbc_file(int cipher,const unsigned char * key,unsigned long keylen,const char * filename,unsigned char * out,unsigned long * outlen)30 int xcbc_file(int cipher,
31 const unsigned char *key, unsigned long keylen,
32 const char *filename,
33 unsigned char *out, unsigned long *outlen)
34 {
35 #ifdef LTC_NO_FILE
36 return CRYPT_NOP;
37 #else
38 int err, x;
39 xcbc_state xcbc;
40 FILE *in;
41 unsigned char buf[512];
42
43 LTC_ARGCHK(key != NULL);
44 LTC_ARGCHK(filename != NULL);
45 LTC_ARGCHK(out != NULL);
46 LTC_ARGCHK(outlen != NULL);
47
48 in = fopen(filename, "rb");
49 if (in == NULL) {
50 return CRYPT_FILE_NOTFOUND;
51 }
52
53 if ((err = xcbc_init(&xcbc, cipher, key, keylen)) != CRYPT_OK) {
54 fclose(in);
55 return err;
56 }
57
58 do {
59 x = fread(buf, 1, sizeof(buf), in);
60 if ((err = xcbc_process(&xcbc, buf, x)) != CRYPT_OK) {
61 fclose(in);
62 return err;
63 }
64 } while (x == sizeof(buf));
65 fclose(in);
66
67 if ((err = xcbc_done(&xcbc, out, outlen)) != CRYPT_OK) {
68 return err;
69 }
70
71 #ifdef LTC_CLEAN_STACK
72 zeromem(buf, sizeof(buf));
73 #endif
74
75 return CRYPT_OK;
76 #endif
77 }
78
79 #endif
80
81 /* $Source: /cvs/libtom/libtomcrypt/src/mac/xcbc/xcbc_file.c,v $ */
82 /* $Revision: 1.1 $ */
83 /* $Date: 2006/11/03 01:56:41 $ */
84