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/*
* lib/krb5/krb/get_fcreds.c
*
* Copyright 1994 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_get_for_creds()
*/
/* XXX This API is going to change; what's here isn't general enough! XXX */
/* XXX Once we finalize the API, it should go into func-proto.h and */
/* into the API doc. */
/* General-purpose forwarding routines. These routines may be put into */
/* libkrb5.a to allow widespread use */
#include <stdio.h>
#ifndef _MSDOS
#include <pwd.h>
#include <netdb.h>
#include "k5-int.h"
#define KRB5_DEFAULT_LIFE 60*60*8 /* 8 hours */
/* helper function: convert flags to necessary KDC options */
#define flags2options(flags) (flags & KDC_TKT_COMMON_MASK)
/* Get a TGT for use at the remote host */
krb5_error_code INTERFACE
krb5_get_for_creds(context, sumtype, rhost, client, enc_key,
forwardable, outbuf)
krb5_context context;
const krb5_cksumtype sumtype;
char *rhost;
krb5_principal client;
krb5_keyblock *enc_key;
int forwardable; /* Should forwarded TGT also be forwardable? */
krb5_data *outbuf;
{
struct hostent *hp;
krb5_enctype etype;
krb5_address **addrs;
krb5_error_code retval;
krb5_data *scratch;
krb5_kdc_rep *dec_rep = 0;
krb5_error *err_reply;
krb5_response tgsrep;
krb5_creds creds, tgt;
krb5_ccache cc;
krb5_flags kdcoptions;
krb5_timestamp now;
char *remote_host = 0;
char **hrealms = 0;
int i;
memset((char *)&creds, 0, sizeof(creds));
memset((char *)&tgsrep, 0, sizeof(tgsrep));
if (!rhost || !(hp = gethostbyname(rhost)))
return KRB5_ERR_BAD_HOSTNAME;
remote_host = (char *) malloc(strlen(hp->h_name)+1);
if (!remote_host) {
retval = ENOMEM;
goto errout;
}
strcpy(remote_host, hp->h_name);
if (retval = krb5_get_host_realm(context, remote_host, &hrealms))
goto errout;
if (!hrealms[0]) {
retval = KRB5_ERR_HOST_REALM_UNKNOWN;
goto errout;
}
/* Count elements */
for(i=0; hp->h_addr_list[i]; i++);
addrs = (krb5_address **) malloc ((i+1)*sizeof(*addrs));
if (!addrs) {
retval = ENOMEM;
goto errout;
}
memset(addrs, 0, (i+1)*sizeof(*addrs));
for(i=0; hp->h_addr_list[i]; i++) {
addrs[i] = (krb5_address *) malloc(sizeof(krb5_address));
if (!addrs[i]) {
retval = ENOMEM;
goto errout;
}
addrs[i]->addrtype = hp->h_addrtype;
addrs[i]->length = hp->h_length;
addrs[i]->contents = (unsigned char *)malloc(addrs[i]->length);
if (!addrs[i]->contents) {
retval = ENOMEM;
goto errout;
}
memcpy ((char *)addrs[i]->contents, hp->h_addr_list[i],
addrs[i]->length);
}
addrs[i] = 0;
if (retval = krb5_copy_principal(context, client, &creds.client))
goto errout;
if (retval = krb5_build_principal_ext(context, &creds.server,
strlen(hrealms[0]),
hrealms[0],
KRB5_TGS_NAME_SIZE,
KRB5_TGS_NAME,
client->realm.length,
client->realm.data,
0))
goto errout;
creds.times.starttime = 0;
if (retval = krb5_timeofday(context, &now))
goto errout;
creds.times.endtime = now + KRB5_DEFAULT_LIFE;
creds.times.renew_till = 0;
if (retval = krb5_cc_default(context, &cc))
goto errout;
/* fetch tgt directly from cache */
retval = krb5_cc_retrieve_cred (context, cc, KRB5_TC_MATCH_SRV_NAMEONLY,
&creds, &tgt);
krb5_cc_close(context, cc);
if (retval)
goto errout;
/* tgt->client must be equal to creds.client */
if (!krb5_principal_compare(context, tgt.client, creds.client)) {
retval = KRB5_PRINC_NOMATCH;
goto errout;
}
if (!tgt.ticket.length) {
retval = KRB5_NO_TKT_SUPPLIED;
goto errout;
}
kdcoptions = flags2options(tgt.ticket_flags)|KDC_OPT_FORWARDED;
if (!forwardable) /* Reset KDC_OPT_FORWARDABLE */
kdcoptions &= ~(KDC_OPT_FORWARDABLE);
if (retval = krb5_send_tgs(context, kdcoptions, &creds.times, NULL,
sumtype, tgt.server, addrs, creds.authdata,
0, /* no padata */
0, /* no second ticket */
&tgt, &tgsrep))
goto errout;
switch (tgsrep.message_type) {
case KRB5_TGS_REP:
break;
case KRB5_ERROR:
default:
if (!krb5_is_krb_error(&tgsrep.response)) {
retval = KRB5KRB_AP_ERR_MSG_TYPE;
goto errout;
} else {
if (retval = decode_krb5_error(&tgsrep.response, &err_reply))
goto errout;
}
retval = err_reply->error + ERROR_TABLE_BASE_krb5;
krb5_free_error(context, err_reply);
goto errout;
}
etype = tgt.keyblock.etype;
if (retval = krb5_decode_kdc_rep(context, &tgsrep.response,
&tgt.keyblock,
etype, /* enctype */
&dec_rep))
goto errout;
if (dec_rep->msg_type != KRB5_TGS_REP) {
retval = KRB5KRB_AP_ERR_MSG_TYPE;
goto errout;
}
/* now it's decrypted and ready for prime time */
if (!krb5_principal_compare(context, dec_rep->client, tgt.client)) {
retval = KRB5_KDCREP_MODIFIED;
goto errout;
}
retval = krb5_mk_cred(context, dec_rep, etype, enc_key, 0, 0, outbuf);
errout:
if (remote_host)
free(remote_host);
if (hrealms)
krb5_xfree(hrealms);
if (addrs)
krb5_free_addresses(context, addrs);
krb5_free_cred_contents(context, &creds);
if (tgsrep.response.data)
free(tgsrep.response.data);
if (dec_rep)
krb5_free_kdc_rep(context, dec_rep);
return retval;
}
#endif
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