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/*
* lib/krb5/krb/encode_kdc.c
*
* Copyright 1990 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_encode_kdc_rep() function.
*/
#include "k5-int.h"
/*
Takes KDC rep parts in *rep and *encpart, and formats it into *enc_rep,
using message type type and encryption key client_key and encryption type
etype.
The string *enc_rep will be allocated before formatting; the caller should
free when finished.
returns system errors
dec_rep->enc_part.ciphertext is allocated and filled in.
*/
/* due to argument promotion rules, we need to use the DECLARG/OLDDECLARG
stuff... */
krb5_error_code
krb5_encode_kdc_rep(context, type, encpart, client_key, dec_rep, enc_rep)
krb5_context context;
const krb5_msgtype type;
const krb5_enc_kdc_rep_part * encpart;
const krb5_keyblock * client_key;
krb5_kdc_rep * dec_rep;
krb5_data ** enc_rep;
{
krb5_data *scratch;
krb5_error_code retval;
krb5_enc_kdc_rep_part tmp_encpart;
krb5_encrypt_block eblock;
if (!valid_enctype(dec_rep->enc_part.enctype))
return KRB5_PROG_ETYPE_NOSUPP;
switch (type) {
case KRB5_AS_REP:
case KRB5_TGS_REP:
break;
default:
return KRB5_BADMSGTYPE;
}
/*
* We don't want to modify encpart, but we need to be able to pass
* in the message type to the encoder, so it can set the ASN.1
* type correct.
*
* Although note that it may be doing nothing with the message
* type, to be compatible with old versions of Kerberos that always
* encode this as a TGS_REP regardly of what it really should be;
* also note that the reason why we are passing it in a structure
* instead of as an argument to encode_krb5_enc_kdc_rep_part (the
* way we should) is for compatibility with the ISODE version of
* this fuction. Ah, compatibility....
*/
tmp_encpart = *encpart;
tmp_encpart.msg_type = type;
retval = encode_krb5_enc_kdc_rep_part(&tmp_encpart, &scratch);
if (retval) {
return retval;
}
memset(&tmp_encpart, 0, sizeof(tmp_encpart));
#define cleanup_scratch() { (void) memset(scratch->data, 0, scratch->length); \
krb5_free_data(context, scratch); }
krb5_use_enctype(context, &eblock, client_key->enctype);
dec_rep->enc_part.ciphertext.length =
krb5_encrypt_size(scratch->length, eblock.crypto_entry);
/* add padding area, and zero it */
if (!(scratch->data = realloc(scratch->data,
dec_rep->enc_part.ciphertext.length))) {
/* may destroy scratch->data */
krb5_xfree(scratch);
return ENOMEM;
}
memset(scratch->data + scratch->length, 0,
dec_rep->enc_part.ciphertext.length - scratch->length);
if (!(dec_rep->enc_part.ciphertext.data =
malloc(dec_rep->enc_part.ciphertext.length))) {
retval = ENOMEM;
goto clean_scratch;
}
#define cleanup_encpart() { \
(void) memset(dec_rep->enc_part.ciphertext.data, 0, \
dec_rep->enc_part.ciphertext.length); \
free(dec_rep->enc_part.ciphertext.data); \
dec_rep->enc_part.ciphertext.length = 0; \
dec_rep->enc_part.ciphertext.data = 0;}
retval = krb5_process_key(context, &eblock, client_key);
if (retval) {
goto clean_encpart;
}
#define cleanup_prockey() {(void) krb5_finish_key(context, &eblock);}
retval = krb5_encrypt(context, (krb5_pointer) scratch->data,
(krb5_pointer) dec_rep->enc_part.ciphertext.data,
scratch->length, &eblock, 0);
if (retval) {
goto clean_prockey;
}
dec_rep->enc_part.enctype = krb5_eblock_enctype(context, &eblock);
/* do some cleanup */
cleanup_scratch();
retval = krb5_finish_key(context, &eblock);
if (retval) {
cleanup_encpart();
return retval;
}
/* now it's ready to be encoded for the wire! */
switch (type) {
case KRB5_AS_REP:
retval = encode_krb5_as_rep(dec_rep, enc_rep);
break;
case KRB5_TGS_REP:
retval = encode_krb5_tgs_rep(dec_rep, enc_rep);
break;
}
if (retval)
cleanup_encpart();
return retval;
clean_prockey:
cleanup_prockey();
clean_encpart:
cleanup_encpart();
clean_scratch:
cleanup_scratch();
return retval;
}
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