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
110
111
|
/*
* lib/krb5/krb/rd_rep.c
*
* Copyright 1990,1991 by the Massachusetts Institute of Technology.
* All Rights Reserved.
*
* Export of this software from the United States of America may
* require a specific license from the United States Government.
* It is the responsibility of any person or organization contemplating
* export to obtain such a license before exporting.
*
* WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
* distribute this software and its documentation for any purpose and
* without fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright notice and
* this permission notice appear in supporting documentation, and that
* the name of M.I.T. not be used in advertising or publicity pertaining
* to distribution of the software without specific, written prior
* permission. M.I.T. makes no representations about the suitability of
* this software for any purpose. It is provided "as is" without express
* or implied warranty.
*
*
* krb5_rd_rep()
*/
#include <krb5/krb5.h>
#include <krb5/ext-proto.h>
#include <krb5/los-proto.h>
#include <krb5/asn1.h>
/*
* Parses a KRB_AP_REP message, returning its contents.
*
* repl is filled in with with a pointer to allocated memory containing
* the fields from the encrypted response.
*
* the key in kblock is used to decrypt the message.
*
* returns system errors, encryption errors, replay errors
*/
krb5_error_code INTERFACE
krb5_rd_rep(context, inbuf, kblock, repl)
krb5_context context;
const krb5_data *inbuf;
const krb5_keyblock *kblock;
krb5_ap_rep_enc_part **repl;
{
krb5_error_code retval;
krb5_ap_rep *reply;
krb5_encrypt_block eblock;
krb5_data scratch;
if (!krb5_is_ap_rep(inbuf))
return KRB5KRB_AP_ERR_MSG_TYPE;
if (!valid_keytype(kblock->keytype))
return KRB5_PROG_KEYTYPE_NOSUPP;
/* decode it */
if (retval = decode_krb5_ap_rep(inbuf, &reply))
return retval;
/* put together an eblock for this encryption */
if (!valid_etype(reply->enc_part.etype)) {
krb5_free_ap_rep(context, reply);
return KRB5_PROG_ETYPE_NOSUPP;
}
krb5_use_cstype(context, &eblock, reply->enc_part.etype);
scratch.length = reply->enc_part.ciphertext.length;
if (!(scratch.data = malloc(scratch.length))) {
krb5_free_ap_rep(context, reply);
return(ENOMEM);
}
/* do any necessary key pre-processing */
if (retval = krb5_process_key(context, &eblock, kblock)) {
errout:
free(scratch.data);
krb5_free_ap_rep(context, reply);
return(retval);
}
/* call the encryption routine */
if (retval = krb5_decrypt(context, (krb5_pointer) reply->enc_part.ciphertext.data,
(krb5_pointer) scratch.data,
scratch.length, &eblock, 0)) {
(void) krb5_finish_key(context, &eblock);
goto errout;
}
#define clean_scratch() {memset(scratch.data, 0, scratch.length); \
free(scratch.data);}
/* finished with the top-level encoding of the ap_rep */
krb5_free_ap_rep(context, reply);
if (retval = krb5_finish_key(context, &eblock)) {
clean_scratch();
return retval;
}
/* now decode the decrypted stuff */
retval = decode_krb5_ap_rep_enc_part(&scratch, repl);
clean_scratch();
if ((*repl)->subkey)
(*repl)->subkey->etype = reply->enc_part.etype;
return retval;
}
|