xref: /titanic_51/usr/src/uts/common/gssapi/mechs/krb5/crypto/verify_checksum.c (revision 159d09a20817016f09b3ea28d1bdada4a336bb91)
1 /*
2  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 
7 /*
8  * Copyright (C) 1998 by the FundsXpress, INC.
9  *
10  * All rights reserved.
11  *
12  * Export of this software from the United States of America may require
13  * a specific license from the United States Government.  It is the
14  * responsibility of any person or organization contemplating export to
15  * obtain such a license before exporting.
16  *
17  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
18  * distribute this software and its documentation for any purpose and
19  * without fee is hereby granted, provided that the above copyright
20  * notice appear in all copies and that both that copyright notice and
21  * this permission notice appear in supporting documentation, and that
22  * the name of FundsXpress. not be used in advertising or publicity pertaining
23  * to distribution of the software without specific, written prior
24  * permission.  FundsXpress makes no representations about the suitability of
25  * this software for any purpose.  It is provided "as is" without express
26  * or implied warranty.
27  *
28  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
29  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
30  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
31  */
32 
33 #include "k5-int.h"
34 #include "cksumtypes.h"
35 
36 krb5_error_code KRB5_CALLCONV
37 krb5_c_verify_checksum(krb5_context context, const krb5_keyblock *key,
38 		       krb5_keyusage usage, const krb5_data *data,
39 		       const krb5_checksum *cksum, krb5_boolean *valid)
40 {
41     int i;
42     size_t hashsize;
43     krb5_error_code ret;
44     krb5_data indata;
45     krb5_checksum computed;
46 
47     for (i=0; i<krb5_cksumtypes_length; i++) {
48 	if (krb5_cksumtypes_list[i].ctype == cksum->checksum_type)
49 	    break;
50     }
51 
52     if (i == krb5_cksumtypes_length)
53 	return(KRB5_BAD_ENCTYPE);
54 
55     /* if there's actually a verify function, call it */
56 
57     indata.length = cksum->length;
58     indata.data = (char *) cksum->contents;
59     *valid = 0;
60 
61     if (krb5_cksumtypes_list[i].keyhash &&
62 	krb5_cksumtypes_list[i].keyhash->verify)
63 	return((*(krb5_cksumtypes_list[i].keyhash->verify))(
64 		context, key, usage, 0, data, &indata, valid));
65 
66     /* otherwise, make the checksum again, and compare */
67 
68     if ((ret = krb5_c_checksum_length(context, cksum->checksum_type, &hashsize)))
69 	return(ret);
70 
71     if (cksum->length != hashsize)
72 	return(KRB5_BAD_MSIZE);
73 
74     computed.length = hashsize;
75 
76     if ((ret = krb5_c_make_checksum(context, cksum->checksum_type, key, usage,
77 				   data, &computed))) {
78 	FREE(computed.contents, computed.length);
79 	return(ret);
80     }
81 
82     *valid = (memcmp(computed.contents, cksum->contents, hashsize) == 0);
83 
84     FREE(computed.contents, computed.length);
85 
86     return(0);
87 }
88