1
0
mirror of https://github.com/samba-team/samba.git synced 2024-12-23 17:34:34 +03:00
samba-mirror/source3/libads/krb5_setpw.c

519 lines
14 KiB
C
Raw Normal View History

/*
Unix SMB/CIFS implementation.
krb5 set password implementation
Copyright (C) Andrew Tridgell 2001
Copyright (C) Remus Koos 2001 (remuskoos@yahoo.com)
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
#define DEFAULT_KPASSWD_PORT 464
#define KRB5_KPASSWD_VERS_CHANGEPW 1
#define KRB5_KPASSWD_VERS_SETPW 0xff80
#define KRB5_KPASSWD_ACCESSDENIED 5
#define KRB5_KPASSWD_BAD_VERSION 6
/* This implements the Kerb password change protocol as specifed in
* kerb-chg-password-02.txt
*/
static DATA_BLOB encode_krb5_setpw(const char *principal, const char *password)
{
char* princ_part1 = NULL;
char* princ_part2 = NULL;
char* realm = NULL;
char* c;
char* princ;
ASN1_DATA req;
DATA_BLOB ret;
princ = strdup(principal);
if ((c = strchr(princ, '/')) == NULL) {
c = princ;
} else {
*c = '\0';
c++;
princ_part1 = princ;
}
princ_part2 = c;
if ((c = strchr(c, '@')) != NULL) {
*c = '\0';
c++;
realm = c;
}
memset(&req, 0, sizeof(req));
asn1_push_tag(&req, ASN1_SEQUENCE(0));
asn1_push_tag(&req, ASN1_CONTEXT(0));
asn1_write_OctetString(&req, password, strlen(password));
asn1_pop_tag(&req);
asn1_push_tag(&req, ASN1_CONTEXT(1));
asn1_push_tag(&req, ASN1_SEQUENCE(0));
asn1_push_tag(&req, ASN1_CONTEXT(0));
asn1_write_Integer(&req, 1);
asn1_pop_tag(&req);
asn1_push_tag(&req, ASN1_CONTEXT(1));
asn1_push_tag(&req, ASN1_SEQUENCE(0));
if (princ_part1)
asn1_write_GeneralString(&req, princ_part1);
asn1_write_GeneralString(&req, princ_part2);
asn1_pop_tag(&req);
asn1_pop_tag(&req);
asn1_pop_tag(&req);
asn1_pop_tag(&req);
asn1_push_tag(&req, ASN1_CONTEXT(2));
asn1_write_GeneralString(&req, realm);
asn1_pop_tag(&req);
asn1_pop_tag(&req);
ret = data_blob(req.data, req.length);
asn1_free(&req);
free(princ);
return ret;
}
static krb5_error_code build_setpw_request(krb5_context context,
krb5_auth_context auth_context,
krb5_data *ap_req,
const char *princ,
const char *passwd,
krb5_data *packet)
{
krb5_error_code ret;
krb5_data cipherpw;
krb5_data encoded_setpw;
krb5_replay_data replay;
char *p;
DATA_BLOB setpw;
ret = krb5_auth_con_setflags(context,
auth_context,KRB5_AUTH_CONTEXT_DO_SEQUENCE);
if (ret) {
DEBUG(1,("krb5_auth_con_setflags failed (%s)\n",
error_message(ret)));
return ret;
}
setpw = encode_krb5_setpw(princ, passwd);
encoded_setpw.data = setpw.data;
encoded_setpw.length = setpw.length;
ret = krb5_mk_priv(context, auth_context,
&encoded_setpw, &cipherpw, &replay);
data_blob_free(&setpw); /*from 'encode_krb5_setpw(...)' */
if (ret) {
DEBUG(1,("krb5_mk_priv failed (%s)\n", error_message(ret)));
return ret;
}
packet->data = (char *)malloc(ap_req->length + cipherpw.length + 6);
if (!packet->data)
return -1;
/* see the RFC for details */
p = ((char *)packet->data) + 2;
RSSVAL(p, 0, 0xff80);
p += 2;
RSSVAL(p, 0, ap_req->length);
p += 2;
memcpy(p, ap_req->data, ap_req->length);
p += ap_req->length;
memcpy(p, cipherpw.data, cipherpw.length);
p += cipherpw.length;
packet->length = PTR_DIFF(p,packet->data);
RSSVAL(packet->data, 0, packet->length);
free(cipherpw.data); /* from 'krb5_mk_priv(...)' */
return 0;
}
static krb5_error_code parse_setpw_reply(krb5_context context,
krb5_auth_context auth_context,
krb5_data *packet)
{
krb5_data ap_rep;
char *p;
int vnum, ret, res_code;
krb5_data cipherresult;
krb5_data clearresult;
krb5_ap_rep_enc_part *ap_rep_enc;
krb5_replay_data replay;
if (packet->length < 4) {
return KRB5KRB_AP_ERR_MODIFIED;
}
p = packet->data;
if (((char *)packet->data)[0] == 0x7e || ((char *)packet->data)[0] == 0x5e) {
/* it's an error packet. We should parse it ... */
DEBUG(1,("Got error packet 0x%x from kpasswd server\n",
((char *)packet->data)[0]));
return KRB5KRB_AP_ERR_MODIFIED;
}
if (RSVAL(p, 0) != packet->length) {
DEBUG(1,("Bad packet length (%d/%d) from kpasswd server\n",
RSVAL(p, 0), packet->length));
return KRB5KRB_AP_ERR_MODIFIED;
}
p += 2;
vnum = RSVAL(p, 0); p += 2;
if (vnum != KRB5_KPASSWD_VERS_SETPW && vnum != KRB5_KPASSWD_VERS_CHANGEPW) {
DEBUG(1,("Bad vnum (%d) from kpasswd server\n", vnum));
return KRB5KDC_ERR_BAD_PVNO;
}
ap_rep.length = RSVAL(p, 0); p += 2;
if (p + ap_rep.length >= (char *)packet->data + packet->length) {
DEBUG(1,("ptr beyond end of packet from kpasswd server\n"));
return KRB5KRB_AP_ERR_MODIFIED;
}
if (ap_rep.length == 0) {
DEBUG(1,("got unencrypted setpw result?!\n"));
return KRB5KRB_AP_ERR_MODIFIED;
}
/* verify ap_rep */
ap_rep.data = p;
p += ap_rep.length;
ret = krb5_rd_rep(context, auth_context, &ap_rep, &ap_rep_enc);
if (ret) {
DEBUG(1,("failed to rd setpw reply (%s)\n", error_message(ret)));
return KRB5KRB_AP_ERR_MODIFIED;
}
krb5_free_ap_rep_enc_part(context, ap_rep_enc);
cipherresult.data = p;
cipherresult.length = ((char *)packet->data + packet->length) - p;
ret = krb5_rd_priv(context, auth_context, &cipherresult, &clearresult,
&replay);
if (ret) {
DEBUG(1,("failed to decrypt setpw reply (%s)\n", error_message(ret)));
return KRB5KRB_AP_ERR_MODIFIED;
}
if (clearresult.length < 2) {
free(clearresult.data);
ret = KRB5KRB_AP_ERR_MODIFIED;
return KRB5KRB_AP_ERR_MODIFIED;
}
p = clearresult.data;
res_code = RSVAL(p, 0);
free(clearresult.data);
if ((res_code < KRB5_KPASSWD_SUCCESS) ||
(res_code >= KRB5_KPASSWD_ACCESSDENIED)) {
return KRB5KRB_AP_ERR_MODIFIED;
}
return 0;
}
ADS_STATUS krb5_set_password(const char *kdc_host, const char *princ, const char *newpw,
int time_offset)
{
krb5_context context;
krb5_auth_context auth_context = NULL;
krb5_principal principal;
char *princ_name;
char *realm;
krb5_creds creds, *credsp;
krb5_ccache ccache;
krb5_data ap_req, chpw_req, chpw_rep;
int ret, sock, addr_len;
struct sockaddr remote_addr, local_addr;
krb5_address local_kaddr, remote_kaddr;
ret = krb5_init_context(&context);
if (ret) {
DEBUG(1,("Failed to init krb5 context (%s)\n", error_message(ret)));
return ADS_ERROR_KRB5(ret);
}
if (time_offset != 0) {
krb5_set_real_time(context, time(NULL) + time_offset, 0);
}
ret = krb5_cc_default(context, &ccache);
if (ret) {
krb5_free_context(context);
DEBUG(1,("Failed to get default creds (%s)\n", error_message(ret)));
return ADS_ERROR_KRB5(ret);
}
ZERO_STRUCT(creds);
realm = strchr(princ, '@');
realm++;
asprintf(&princ_name, "kadmin/changepw@%s", realm);
ret = krb5_parse_name(context, princ_name, &creds.server);
if (ret) {
krb5_free_context(context);
DEBUG(1,("Failed to parse kadmin/changepw (%s)\n", error_message(ret)));
return ADS_ERROR_KRB5(ret);
}
free(princ_name);
/* parse the principal we got as a function argument */
ret = krb5_parse_name(context, princ, &principal);
if (ret) {
krb5_free_context(context);
DEBUG(1,("Failed to parse %s (%s)\n", princ_name, error_message(ret)));
return ADS_ERROR_KRB5(ret);
}
krb5_princ_set_realm(context, creds.server,
krb5_princ_realm(context, principal));
ret = krb5_cc_get_principal(context, ccache, &creds.client);
if (ret) {
krb5_free_principal(context, principal);
krb5_free_context(context);
DEBUG(1,("Failed to get principal from ccache (%s)\n",
error_message(ret)));
return ADS_ERROR_KRB5(ret);
}
ret = krb5_get_credentials(context, 0, ccache, &creds, &credsp);
if (ret) {
krb5_free_principal(context, creds.client);
krb5_free_principal(context, principal);
krb5_free_context(context);
DEBUG(1,("krb5_get_credentials failed (%s)\n", error_message(ret)));
return ADS_ERROR_KRB5(ret);
}
/* we might have to call krb5_free_creds(...) from now on ... */
ret = krb5_mk_req_extended(context, &auth_context, AP_OPTS_USE_SUBKEY,
NULL, credsp, &ap_req);
if (ret) {
krb5_free_creds(context, credsp);
krb5_free_principal(context, creds.client);
krb5_free_principal(context, principal);
krb5_free_context(context);
DEBUG(1,("krb5_mk_req_extended failed (%s)\n", error_message(ret)));
return ADS_ERROR_KRB5(ret);
}
sock = open_udp_socket(kdc_host, DEFAULT_KPASSWD_PORT);
if (sock == -1) {
int rc = errno;
free(ap_req.data);
krb5_free_creds(context, credsp);
krb5_free_principal(context, creds.client);
krb5_free_principal(context, principal);
krb5_free_context(context);
DEBUG(1,("failed to open kpasswd socket to %s (%s)\n",
kdc_host, strerror(errno)));
return ADS_ERROR_SYSTEM(rc);
}
addr_len = sizeof(remote_addr);
getpeername(sock, &remote_addr, &addr_len);
addr_len = sizeof(local_addr);
getsockname(sock, &local_addr, &addr_len);
setup_kaddr(&remote_kaddr, &remote_addr);
setup_kaddr(&local_kaddr, &local_addr);
ret = krb5_auth_con_setaddrs(context, auth_context, &local_kaddr, NULL);
if (ret) {
close(sock);
free(ap_req.data);
krb5_free_creds(context, credsp);
krb5_free_principal(context, creds.client);
krb5_free_principal(context, principal);
krb5_free_context(context);
DEBUG(1,("krb5_auth_con_setaddrs failed (%s)\n", error_message(ret)));
return ADS_ERROR_KRB5(ret);
}
ret = build_setpw_request(context, auth_context, &ap_req,
princ, newpw, &chpw_req);
if (ret) {
close(sock);
free(ap_req.data);
krb5_free_creds(context, credsp);
krb5_free_principal(context, creds.client);
krb5_free_principal(context, principal);
krb5_free_context(context);
DEBUG(1,("build_setpw_request failed (%s)\n", error_message(ret)));
return ADS_ERROR_KRB5(ret);
}
if (write(sock, chpw_req.data, chpw_req.length) != chpw_req.length) {
close(sock);
free(chpw_req.data);
free(ap_req.data);
krb5_free_creds(context, credsp);
krb5_free_principal(context, creds.client);
krb5_free_principal(context, principal);
krb5_free_context(context);
DEBUG(1,("send of chpw failed (%s)\n", strerror(errno)));
return ADS_ERROR_SYSTEM(errno);
}
free(chpw_req.data);
chpw_rep.length = 1500;
chpw_rep.data = (char *) malloc(chpw_rep.length);
if (!chpw_rep.data) {
close(sock);
free(ap_req.data);
krb5_free_creds(context, credsp);
krb5_free_principal(context, creds.client);
krb5_free_principal(context, principal);
krb5_free_context(context);
DEBUG(1,("send of chpw failed (%s)\n", strerror(errno)));
errno = ENOMEM;
return ADS_ERROR_SYSTEM(errno);
}
ret = read(sock, chpw_rep.data, chpw_rep.length);
if (ret < 0) {
close(sock);
free(chpw_rep.data);
free(ap_req.data);
krb5_free_creds(context, credsp);
krb5_free_principal(context, creds.client);
krb5_free_principal(context, principal);
krb5_free_context(context);
DEBUG(1,("recv of chpw reply failed (%s)\n", strerror(errno)));
return ADS_ERROR_SYSTEM(errno);
}
close(sock);
chpw_rep.length = ret;
ret = krb5_auth_con_setaddrs(context, auth_context, NULL,&remote_kaddr);
if (ret) {
free(chpw_rep.data);
free(ap_req.data);
krb5_free_creds(context, credsp);
krb5_free_principal(context, creds.client);
krb5_free_principal(context, principal);
krb5_free_context(context);
DEBUG(1,("krb5_auth_con_setaddrs on reply failed (%s)\n",
error_message(ret)));
return ADS_ERROR_KRB5(ret);
}
ret = parse_setpw_reply(context, auth_context, &chpw_rep);
free(chpw_rep.data);
if (ret) {
free(ap_req.data);
krb5_free_creds(context, credsp);
krb5_free_principal(context, creds.client);
krb5_free_principal(context, principal);
krb5_free_context(context);
DEBUG(1,("parse_setpw_reply failed (%s)\n",
error_message(ret)));
return ADS_ERROR_KRB5(ret);
}
free(ap_req.data);
krb5_free_creds(context, credsp);
krb5_free_principal(context, creds.client);
krb5_free_principal(context, principal);
krb5_free_context(context);
return ADS_SUCCESS;
}
ADS_STATUS kerberos_set_password(const char *kpasswd_server,
const char *auth_principal, const char *auth_password,
const char *target_principal, const char *new_password,
int time_offset)
{
int ret;
if ((ret = kerberos_kinit_password(auth_principal, auth_password, time_offset))) {
DEBUG(1,("Failed kinit for principal %s (%s)\n", auth_principal, error_message(ret)));
return ADS_ERROR_KRB5(ret);
}
return krb5_set_password(kpasswd_server, target_principal, new_password, time_offset);
}
/**
* Set the machine account password
* @param ads connection to ads server
* @param hostname machine whose password is being set
* @param password new password
* @return status of password change
**/
ADS_STATUS ads_set_machine_password(ADS_STRUCT *ads,
const char *hostname,
const char *password)
{
ADS_STATUS status;
char *host = strdup(hostname);
char *principal;
strlower(host);
/*
we need to use the '$' form of the name here, as otherwise the
server might end up setting the password for a user instead
*/
asprintf(&principal, "%s$@%s", host, ads->auth.realm);
status = krb5_set_password(ads->auth.kdc_server, principal, password, ads->auth.time_offset);
free(host);
free(principal);
return status;
}
#endif