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/*
* lib/krb5/krb/mk_rep.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_mk_rep()
*/
#include "k5-int.h"
#include "auth_con.h"
/*
Formats a KRB_AP_REP message into outbuf.
The outbuf buffer storage is allocated, and should be freed by the
caller when finished.
returns system errors
*/
krb5_error_code
krb5_mk_rep(context, auth_context, outbuf)
krb5_context context;
krb5_auth_context auth_context;
krb5_data * outbuf;
{
krb5_error_code retval;
krb5_enctype enctype;
krb5_ap_rep_enc_part repl;
krb5_encrypt_block eblock;
krb5_ap_rep reply;
krb5_data * scratch;
krb5_data * toutbuf;
/* verify a valid enctype is available */
if (!valid_enctype(enctype = auth_context->keyblock->enctype))
return KRB5_PROG_ETYPE_NOSUPP;
/* Make the reply */
if (((auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) ||
(auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_SEQUENCE)) &&
(auth_context->local_seq_number == 0)) {
if ((retval = krb5_generate_seq_number(context, auth_context->keyblock,
&auth_context->local_seq_number)))
return(retval);
}
repl.ctime = auth_context->authentp->ctime;
repl.cusec = auth_context->authentp->cusec;
repl.subkey = auth_context->authentp->subkey;
repl.seq_number = auth_context->local_seq_number;
/* encode it before encrypting */
if ((retval = encode_krb5_ap_rep_enc_part(&repl, &scratch)))
return retval;
/* put together an eblock for this encryption */
krb5_use_enctype(context, &eblock, enctype);
reply.enc_part.enctype = enctype;
reply.enc_part.kvno = 0; /* XXX user set? */
reply.enc_part.ciphertext.length = krb5_encrypt_size(scratch->length,
eblock.crypto_entry);
/* add padding area, and zero it */
if (!(scratch->data = realloc(scratch->data,
reply.enc_part.ciphertext.length))) {
/* may destroy scratch->data */
krb5_xfree(scratch);
return ENOMEM;
}
memset(scratch->data + scratch->length, 0,
reply.enc_part.ciphertext.length - scratch->length);
if (!(reply.enc_part.ciphertext.data =
malloc(reply.enc_part.ciphertext.length))) {
retval = ENOMEM;
goto cleanup_scratch;
}
/* do any necessary key pre-processing */
if ((retval = krb5_process_key(context, &eblock, auth_context->keyblock)))
goto cleanup_encpart;
/* call the encryption routine */
if ((retval = krb5_encrypt(context, (krb5_pointer) scratch->data,
(krb5_pointer) reply.enc_part.ciphertext.data,
scratch->length, &eblock, 0))) {
krb5_finish_key(context, &eblock);
goto cleanup_encpart;
}
if ((retval = krb5_finish_key(context, &eblock)))
goto cleanup_encpart;
if (!(retval = encode_krb5_ap_rep(&reply, &toutbuf))) {
*outbuf = *toutbuf;
krb5_xfree(toutbuf);
}
cleanup_encpart:
memset(reply.enc_part.ciphertext.data, 0, reply.enc_part.ciphertext.length);
free(reply.enc_part.ciphertext.data);
reply.enc_part.ciphertext.length = 0;
reply.enc_part.ciphertext.data = 0;
cleanup_scratch:
memset(scratch->data, 0, scratch->length);
krb5_free_data(context, scratch);
return retval;
}
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