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/*
Unix SMB/CIFS implementation.
kerberos utility library
Copyright (C) Andrew Tridgell 2001
Copyright (C) Remus Koos 2001
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "includes.h"
#ifdef HAVE_KRB5
/*
we use a prompter to avoid a crash bug in the kerberos libs when
dealing with empty passwords
this prompter is just a string copy ...
*/
static krb5_error_code
kerb_prompter(krb5_context ctx, void *data,
const char *name,
const char *banner,
int num_prompts,
krb5_prompt prompts[])
{
if (num_prompts == 0) return 0;
memset(prompts[0].reply->data, 0, prompts[0].reply->length);
if (prompts[0].reply->length > 0) {
strncpy(prompts[0].reply->data, data, prompts[0].reply->length-1);
prompts[0].reply->length = strlen(prompts[0].reply->data);
}
return 0;
}
/*
simulate a kinit, putting the tgt in the default cache location
remus@snapserver.com
*/
int kerberos_kinit_password(const char *principal, const char *password)
{
krb5_context ctx;
krb5_error_code code = 0;
krb5_ccache cc;
krb5_principal me;
krb5_creds my_creds;
if ((code = krb5_init_context(&ctx)))
return code;
if ((code = krb5_cc_default(ctx, &cc))) {
krb5_free_context(ctx);
return code;
}
if ((code = krb5_parse_name(ctx, principal, &me))) {
krb5_free_context(ctx);
return code;
}
if ((code = krb5_get_init_creds_password(ctx, &my_creds, me, NULL,
kerb_prompter,
password, 0, NULL, NULL))) {
krb5_free_principal(ctx, me);
krb5_free_context(ctx);
return code;
}
if ((code = krb5_cc_initialize(ctx, cc, me))) {
krb5_free_cred_contents(ctx, &my_creds);
krb5_free_principal(ctx, me);
krb5_free_context(ctx);
return code;
}
if ((code = krb5_cc_store_cred(ctx, cc, &my_creds))) {
krb5_cc_close(ctx, cc);
krb5_free_cred_contents(ctx, &my_creds);
krb5_free_principal(ctx, me);
krb5_free_context(ctx);
return code;
}
krb5_cc_close(ctx, cc);
krb5_free_cred_contents(ctx, &my_creds);
krb5_free_principal(ctx, me);
krb5_free_context(ctx);
return 0;
}
/* run kinit to setup our ccache */
int ads_kinit_password(ADS_STRUCT *ads)
{
char *s;
int ret;
if (!ads->user_name) {
/* by default use the machine account */
extern pstring global_myname;
fstring myname;
fstrcpy(myname, global_myname);
strlower(myname);
asprintf(&ads->user_name, "HOST/%s", global_myname);
}
asprintf(&s, "%s@%s", ads->user_name, ads->realm);
ret = kerberos_kinit_password(s, ads->password);
if (ret) {
DEBUG(0,("kerberos_kinit_password %s failed: %s\n",
s, error_message(ret)));
}
free(s);
return ret;
}
/*
verify an incoming ticket and parse out the principal name and
authorization_data if available
*/
NTSTATUS ads_verify_ticket(ADS_STRUCT *ads, const DATA_BLOB *ticket,
char **principal, DATA_BLOB *auth_data)
{
krb5_context context;
krb5_auth_context auth_context = NULL;
krb5_keytab keytab = NULL;
krb5_data packet;
krb5_ticket *tkt = NULL;
krb5_data salt;
krb5_encrypt_block eblock;
int ret;
krb5_keyblock * key;
krb5_principal host_princ;
char *host_princ_s;
extern pstring global_myname;
fstring myname;
char *password_s;
krb5_data password;
if (!secrets_init()) {
DEBUG(1,("secrets_init failed\n"));
return NT_STATUS_LOGON_FAILURE;
}
password_s = secrets_fetch_machine_password();
if (!password_s) {
DEBUG(1,("failed to fetch machine password\n"));
return NT_STATUS_LOGON_FAILURE;
}
password.data = password_s;
password.length = strlen(password_s);
ret = krb5_init_context(&context);
if (ret) {
DEBUG(1,("krb5_init_context failed (%s)\n", error_message(ret)));
return NT_STATUS_LOGON_FAILURE;
}
ret = krb5_set_default_realm(context, ads->realm);
if (ret) {
DEBUG(1,("krb5_set_default_realm failed (%s)\n", error_message(ret)));
ads_destroy(&ads);
return NT_STATUS_LOGON_FAILURE;
}
/* this whole process is far more complex than I would
like. We have to go through all this to allow us to store
the secret internally, instead of using /etc/krb5.keytab */
ret = krb5_auth_con_init(context, &auth_context);
if (ret) {
DEBUG(1,("krb5_auth_con_init failed (%s)\n", error_message(ret)));
return NT_STATUS_LOGON_FAILURE;
}
fstrcpy(myname, global_myname);
strlower(myname);
asprintf(&host_princ_s, "HOST/%s@%s", myname, lp_realm());
ret = krb5_parse_name(context, host_princ_s, &host_princ);
if (ret) {
DEBUG(1,("krb5_parse_name(%s) failed (%s)\n", host_princ_s, error_message(ret)));
return NT_STATUS_LOGON_FAILURE;
}
ret = krb5_principal2salt(context, host_princ, &salt);
if (ret) {
DEBUG(1,("krb5_principal2salt failed (%s)\n", error_message(ret)));
return NT_STATUS_LOGON_FAILURE;
}
if (!(key = (krb5_keyblock *)malloc(sizeof(*key)))) {
return NT_STATUS_NO_MEMORY;
}
krb5_use_enctype(context, &eblock, ENCTYPE_DES_CBC_MD5);
ret = krb5_string_to_key(context, &eblock, key, &password, &salt);
if (ret) {
DEBUG(1,("krb5_string_to_key failed (%s)\n", error_message(ret)));
return NT_STATUS_LOGON_FAILURE;
}
krb5_auth_con_setuseruserkey(context, auth_context, key);
packet.length = ticket->length;
packet.data = (krb5_pointer)ticket->data;
#if 0
file_save("/tmp/ticket.dat", ticket->data, ticket->length);
#endif
if ((ret = krb5_rd_req(context, &auth_context, &packet,
NULL, keytab, NULL, &tkt))) {
DEBUG(3,("krb5_rd_req with auth failed (%s)\n",
error_message(ret)));
return NT_STATUS_LOGON_FAILURE;
}
if (tkt->enc_part2) {
*auth_data = data_blob(tkt->enc_part2->authorization_data[0]->contents,
tkt->enc_part2->authorization_data[0]->length);
}
#if 0
if (tkt->enc_part2) {
file_save("/tmp/authdata.dat",
tkt->enc_part2->authorization_data[0]->contents,
tkt->enc_part2->authorization_data[0]->length);
}
#endif
if ((ret = krb5_unparse_name(context, tkt->enc_part2->client, principal))) {
DEBUG(3,("krb5_unparse_name failed (%s)\n",
error_message(ret)));
return NT_STATUS_LOGON_FAILURE;
}
return NT_STATUS_OK;
}
#endif
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