1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis */
2 /* SPDX-License-Identifier: Unlicense */
3 #include "tomcrypt_private.h"
4
5 /**
6 @file xcbc_file.c
7 XCBC support, process a file, Tom St Denis
8 */
9
10 #ifdef LTC_XCBC
11
12 /**
13 XCBC a file
14 @param cipher The index of the cipher desired
15 @param key The secret key
16 @param keylen The length of the secret key (octets)
17 @param filename The name of the file you wish to XCBC
18 @param out [out] Where the authentication tag is to be stored
19 @param outlen [in/out] The max size and resulting size of the authentication tag
20 @return CRYPT_OK if successful, CRYPT_NOP if file support has been disabled
21 */
xcbc_file(int cipher,const unsigned char * key,unsigned long keylen,const char * filename,unsigned char * out,unsigned long * outlen)22 int xcbc_file(int cipher,
23 const unsigned char *key, unsigned long keylen,
24 const char *filename,
25 unsigned char *out, unsigned long *outlen)
26 {
27 #ifdef LTC_NO_FILE
28 LTC_UNUSED_PARAM(cipher);
29 LTC_UNUSED_PARAM(key);
30 LTC_UNUSED_PARAM(keylen);
31 LTC_UNUSED_PARAM(filename);
32 LTC_UNUSED_PARAM(out);
33 LTC_UNUSED_PARAM(outlen);
34 return CRYPT_NOP;
35 #else
36 size_t x;
37 int err;
38 xcbc_state xcbc;
39 FILE *in;
40 unsigned char *buf;
41
42 LTC_ARGCHK(key != NULL);
43 LTC_ARGCHK(filename != NULL);
44 LTC_ARGCHK(out != NULL);
45 LTC_ARGCHK(outlen != NULL);
46
47 if ((buf = XMALLOC(LTC_FILE_READ_BUFSIZE)) == NULL) {
48 return CRYPT_MEM;
49 }
50
51 if ((err = xcbc_init(&xcbc, cipher, key, keylen)) != CRYPT_OK) {
52 goto LBL_ERR;
53 }
54
55 in = fopen(filename, "rb");
56 if (in == NULL) {
57 err = CRYPT_FILE_NOTFOUND;
58 goto LBL_ERR;
59 }
60
61 do {
62 x = fread(buf, 1, LTC_FILE_READ_BUFSIZE, in);
63 if ((err = xcbc_process(&xcbc, buf, (unsigned long)x)) != CRYPT_OK) {
64 fclose(in);
65 goto LBL_CLEANBUF;
66 }
67 } while (x == LTC_FILE_READ_BUFSIZE);
68
69 if (fclose(in) != 0) {
70 err = CRYPT_ERROR;
71 goto LBL_CLEANBUF;
72 }
73
74 err = xcbc_done(&xcbc, out, outlen);
75
76 LBL_CLEANBUF:
77 zeromem(buf, LTC_FILE_READ_BUFSIZE);
78 LBL_ERR:
79 #ifdef LTC_CLEAN_STACK
80 zeromem(&xcbc, sizeof(xcbc_state));
81 #endif
82 XFREE(buf);
83 return err;
84 #endif
85 }
86
87 #endif
88