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/*
* lib/krb5/krb/decrypt_tk.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_decrypt_tkt_part() function.
*/
#include "k5-int.h"
/*
Decrypts dec_ticket->enc_part
using *srv_key, and places result in dec_ticket->enc_part2.
The storage of dec_ticket->enc_part2 will be allocated before return.
returns errors from encryption routines, system errors
*/
krb5_error_code
krb5_decrypt_tkt_part(context, srv_key, ticket)
krb5_context context;
const krb5_keyblock *srv_key;
register krb5_ticket *ticket;
{
krb5_enc_tkt_part *dec_tkt_part;
krb5_encrypt_block eblock;
krb5_data scratch;
krb5_error_code retval;
if (!valid_etype(ticket->enc_part.etype))
return KRB5_PROG_ETYPE_NOSUPP;
/* put together an eblock for this encryption */
krb5_use_cstype(context, &eblock, ticket->enc_part.etype);
scratch.length = ticket->enc_part.ciphertext.length;
if (!(scratch.data = malloc(ticket->enc_part.ciphertext.length)))
return(ENOMEM);
/* do any necessary key pre-processing */
retval = krb5_process_key(context, &eblock, srv_key);
if (retval) {
free(scratch.data);
return(retval);
}
/* call the encryption routine */
retval = krb5_decrypt(context, (krb5_pointer) ticket->enc_part.ciphertext.data,
(krb5_pointer) scratch.data,
scratch.length, &eblock, 0);
if (retval) {
(void) krb5_finish_key(context, &eblock);
free(scratch.data);
return retval;
}
#define clean_scratch() {memset(scratch.data, 0, scratch.length); \
free(scratch.data);}
retval = krb5_finish_key(context, &eblock);
if (retval) {
clean_scratch();
return retval;
}
/* now decode the decrypted stuff */
retval = decode_krb5_enc_tkt_part(&scratch, &dec_tkt_part);
if (!retval) {
ticket->enc_part2 = dec_tkt_part;
}
clean_scratch();
ticket->enc_part2->session->etype = ticket->enc_part.etype;
return retval;
}
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