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/*
* lib/krb5/krb/mk_priv.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_mk_priv()
*/
#include <krb5/krb5.h>
#include <krb5/asn1.h>
#include <krb5/los-proto.h>
#include <krb5/ext-proto.h>
/*
Formats a KRB_PRIV message into outbuf.
userdata is formatted as the user data in the message.
etype specifies the encryption type; key specifies the key for the
encryption; sender_addr and recv_addr specify the full addresses (host
and port) of the sender and receiver.
i_vector is used as an initialization vector for the encryption, and if
non-NULL its contents are replaced with the last block of the encrypted
data upon exit.
The outbuf buffer storage is allocated, and should be freed by the
caller when finished.
returns system errors
*/
krb5_error_code
krb5_mk_priv(context, userdata, etype, key, sender_addr, recv_addr,
seq_number, priv_flags, rcache, i_vector, outbuf)
krb5_context context;
const krb5_data * userdata;
const krb5_enctype etype;
const krb5_keyblock * key;
const krb5_address * sender_addr;
const krb5_address * recv_addr;
krb5_int32 seq_number;
krb5_int32 priv_flags;
krb5_rcache rcache;
krb5_pointer i_vector;
krb5_data * outbuf;
{
krb5_error_code retval;
krb5_encrypt_block eblock;
krb5_priv privmsg;
krb5_priv_enc_part privmsg_enc_part;
krb5_data *scratch;
if (!valid_etype(etype))
return KRB5_PROG_ETYPE_NOSUPP;
privmsg.enc_part.etype = etype;
privmsg.enc_part.kvno = 0; /* XXX allow user-set? */
privmsg_enc_part.user_data = *userdata;
privmsg_enc_part.s_address = (krb5_address *)sender_addr;
if (recv_addr)
privmsg_enc_part.r_address = (krb5_address *)recv_addr;
else
privmsg_enc_part.r_address = 0;
if (!(priv_flags & KRB5_PRIV_NOTIME)) {
if (!rcache)
/* gotta provide an rcache in this case... */
return KRB5_RC_REQUIRED;
if (retval = krb5_us_timeofday(context, &privmsg_enc_part.timestamp,
&privmsg_enc_part.usec))
return retval;
} else
privmsg_enc_part.timestamp = 0, privmsg_enc_part.usec = 0;
if (priv_flags & KRB5_PRIV_DOSEQUENCE) {
privmsg_enc_part.seq_number = seq_number;
} else
privmsg_enc_part.seq_number = 0;
/* start by encoding to-be-encrypted part of the message */
if (retval = encode_krb5_enc_priv_part(&privmsg_enc_part, &scratch))
return retval;
#define cleanup_scratch() { (void) memset(scratch->data, 0, scratch->length); krb5_free_data(context, scratch); }
/* put together an eblock for this encryption */
krb5_use_cstype(context, &eblock, etype);
privmsg.enc_part.ciphertext.length = krb5_encrypt_size(scratch->length,
eblock.crypto_entry);
/* add padding area, and zero it */
if (!(scratch->data = realloc(scratch->data,
privmsg.enc_part.ciphertext.length))) {
/* may destroy scratch->data */
krb5_xfree(scratch);
return ENOMEM;
}
memset(scratch->data + scratch->length, 0,
privmsg.enc_part.ciphertext.length - scratch->length);
if (!(privmsg.enc_part.ciphertext.data =
malloc(privmsg.enc_part.ciphertext.length))) {
retval = ENOMEM;
goto clean_scratch;
}
#define cleanup_encpart() {\
(void) memset(privmsg.enc_part.ciphertext.data, 0, \
privmsg.enc_part.ciphertext.length); \
free(privmsg.enc_part.ciphertext.data); \
privmsg.enc_part.ciphertext.length = 0; \
privmsg.enc_part.ciphertext.data = 0;}
/* do any necessary key pre-processing */
if (retval = krb5_process_key(context, &eblock, key)) {
goto clean_encpart;
}
#define cleanup_prockey() {(void) krb5_finish_key(context, &eblock);}
/* call the encryption routine */
if (retval = krb5_encrypt(context, (krb5_pointer) scratch->data,
(krb5_pointer) privmsg.enc_part.ciphertext.data,
scratch->length, &eblock,
i_vector)) {
goto clean_prockey;
}
/* put last block into the i_vector */
if (i_vector)
memcpy(i_vector,
privmsg.enc_part.ciphertext.data +
(privmsg.enc_part.ciphertext.length -
eblock.crypto_entry->block_length),
eblock.crypto_entry->block_length);
/* private message is now assembled-- do some cleanup */
cleanup_scratch();
if (retval = krb5_finish_key(context, &eblock)) {
cleanup_encpart();
return retval;
}
/* encode private message */
if (retval = encode_krb5_priv(&privmsg, &scratch)) {
cleanup_encpart();
return retval;
}
cleanup_encpart();
if (!(priv_flags & KRB5_PRIV_NOTIME)) {
krb5_donot_replay replay;
if (retval = krb5_gen_replay_name(context, sender_addr, "_priv",
&replay.client)) {
cleanup_scratch();
return retval;
}
replay.server = ""; /* XXX */
replay.cusec = privmsg_enc_part.usec;
replay.ctime = privmsg_enc_part.timestamp;
if (retval = krb5_rc_store(context, rcache, &replay)) {
/* should we really error out here? XXX */
cleanup_scratch();
krb5_xfree(replay.client);
return retval;
}
krb5_xfree(replay.client);
}
*outbuf = *scratch;
krb5_xfree(scratch);
return 0;
clean_prockey:
cleanup_prockey();
clean_encpart:
cleanup_encpart();
clean_scratch:
cleanup_scratch();
return retval;
}
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