Remove custom password change code in libads

Use standard libkrb5 calls instead.

Signed-off-by: Simo Sorce <idra@samba.org>
Reviewed-by: Guenther Deschner <gd@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Andrew Bartlet <abartlet@samba.org>

1 files changed, 59 insertions, 555 deletions

diff --git a/source3/libads/krb5_setpw.c b/source3/libads/krb5_setpw.c
index 4286c3b6215..c7bf0ec5373 100644
--- a/source3/libads/krb5_setpw.c
+++ b/source3/libads/krb5_setpw.c
@@ -25,14 +25,7 @@
 
 #ifdef HAVE_KRB5
 
-#define DEFAULT_KPASSWD_PORT	464
-
-#define KRB5_KPASSWD_VERS_CHANGEPW		1
-
-#define KRB5_KPASSWD_VERS_SETPW			0xff80
-#define KRB5_KPASSWD_VERS_SETPW_ALT		2
-
-/* Those are defined by kerberos-set-passwd-02.txt and are probably 
+/* Those are defined by kerberos-set-passwd-02.txt and are probably
  * not supported by M$ implementation */
 #define KRB5_KPASSWD_POLICY_REJECT		8
 #define KRB5_KPASSWD_BAD_PRINCIPAL		9
@@ -43,208 +36,7 @@
  * requests - valid response for CHPW v2 replies.
  */
 
-#define krb5_is_krb_error(packet) \
-	( packet && packet->length && (((char *)packet->data)[0] == 0x7e || ((char *)packet->data)[0] == 0x5e))
-
-/* This implements kerberos password change protocol as specified in 
- * kerb-chg-password-02.txt and kerberos-set-passwd-02.txt
- * as well as microsoft version of the protocol 
- * as specified in kerberos-set-passwd-00.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 = SMB_STRDUP(principal);
-
-	if ((c = strchr_m(princ, '/')) == NULL) {
-		c = princ; 
-	} else {
-		*c = '\0';
-		c++;
-		princ_part1 = princ;
-	}
-
-	princ_part2 = c;
-
-	if ((c = strchr_m(c, '@')) != NULL) {
-		*c = '\0';
-		c++;
-		realm = c;
-	} else {
-		/* We must have a realm component. */
-		return data_blob_null;
-	}
-
-	req = asn1_init(talloc_tos());
-	if (req == NULL) {
-		return data_blob_null;
-	}
-
-	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_kpasswd_request(uint16 pversion,
-					   krb5_context context,
-					   krb5_auth_context auth_context,
-					   krb5_data *ap_req,
-					   const char *princ,
-					   const char *passwd,
-					   bool use_tcp,
-					   krb5_data *packet)
-{
-	krb5_error_code ret;
-	krb5_data cipherpw;
-	krb5_data encoded_setpw;
-	krb5_replay_data replay;
-	char *p, *msg_start;
-	DATA_BLOB setpw;
-	unsigned int msg_length;
-
-	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;
-	}
-
-	/* handle protocol differences in chpw and setpw */
-	if (pversion  == KRB5_KPASSWD_VERS_CHANGEPW)
-		setpw = data_blob(passwd, strlen(passwd));
-	else if (pversion == KRB5_KPASSWD_VERS_SETPW ||
-		 pversion == KRB5_KPASSWD_VERS_SETPW_ALT)
-		setpw = encode_krb5_setpw(princ, passwd);
-	else
-		return EINVAL;
-
-	if (setpw.data == NULL || setpw.length == 0) {
-		return EINVAL;
-	}
-
-	encoded_setpw.data = (char *)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 *)SMB_MALLOC(ap_req->length + cipherpw.length + (use_tcp ? 10 : 6 ));
-	if (!packet->data)
-		return -1;
-
-
-
-	/* see the RFC for details */
-
-	msg_start = p = ((char *)packet->data) + (use_tcp ? 4 : 0);
-	p += 2;
-	RSSVAL(p, 0, pversion);
-	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);
-	msg_length = PTR_DIFF(p,msg_start);
-
-	if (use_tcp) {
-		RSIVAL(packet->data, 0, msg_length);
-	}
-	RSSVAL(msg_start, 0, msg_length);
-	
-	free(cipherpw.data);    /* from 'krb5_mk_priv(...)' */
-
-	return 0;
-}
-
-static const struct kpasswd_errors {
-	int result_code;
-	const char *error_string;
-} kpasswd_errors[] = {
-	{KRB5_KPASSWD_MALFORMED, "Malformed request error"},
-	{KRB5_KPASSWD_HARDERROR, "Server error"},
-	{KRB5_KPASSWD_AUTHERROR, "Authentication error"},
-	{KRB5_KPASSWD_SOFTERROR, "Password change rejected"},
-	{KRB5_KPASSWD_ACCESSDENIED, "Client does not have proper authorization"},
-	{KRB5_KPASSWD_BAD_VERSION, "Protocol version not supported"},
-	{KRB5_KPASSWD_INITIAL_FLAG_NEEDED, "Authorization ticket must have initial flag set"},
-	{KRB5_KPASSWD_POLICY_REJECT, "Password rejected due to policy requirements"},
-	{KRB5_KPASSWD_BAD_PRINCIPAL, "Target principal does not exist"},
-	{KRB5_KPASSWD_ETYPE_NOSUPP, "Unsupported encryption type"},
-	{0, NULL}
-};
-
-static krb5_error_code setpw_result_code_string(krb5_context context,
-						int result_code,
-						const char **code_string)
-{
-        unsigned int idx = 0;
-
-	while (kpasswd_errors[idx].error_string != NULL) {
-		if (kpasswd_errors[idx].result_code == 
-                    result_code) {
-			*code_string = kpasswd_errors[idx].error_string;
-			return 0;
-		}
-		idx++;
-	}
-	*code_string = "Password change failed";
-        return (0);
-}
-
- krb5_error_code kpasswd_err_to_krb5_err(krb5_error_code res_code) 
+static krb5_error_code kpasswd_err_to_krb5_err(krb5_error_code res_code)
 {
 	switch(res_code) {
 		case KRB5_KPASSWD_ACCESSDENIED:
@@ -263,379 +55,72 @@ static krb5_error_code setpw_result_code_string(krb5_context context,
 			return KRB5KRB_ERR_GENERIC;
 	}
 }
-static krb5_error_code parse_setpw_reply(krb5_context context,
-					 bool use_tcp,
-					 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;
-	unsigned int msg_length = packet->length;
-
-
-	if (packet->length < (use_tcp ? 8 : 4)) {
-		return KRB5KRB_AP_ERR_MODIFIED;
-	}
-	
-	p = (char *)packet->data;
-	/*
-	** see if it is an error
-	*/
-	if (krb5_is_krb_error(packet)) {
-
-		ret = handle_krberror_packet(context, packet);
-		if (ret) {
-			return ret;
-		}
-	}
-
-	
-	/* tcp... */
-	if (use_tcp) {
-		msg_length -= 4;
-		if (RIVAL(p, 0) != msg_length) {
-			DEBUG(1,("Bad TCP packet length (%d/%d) from kpasswd server\n",
-			RIVAL(p, 0), msg_length));
-			return KRB5KRB_AP_ERR_MODIFIED;
-		}
-
-		p += 4;
-	}
-	
-	if (RSVAL(p, 0) != msg_length) {
-		DEBUG(1,("Bad packet length (%d/%d) from kpasswd server\n",
-			 RSVAL(p, 0), msg_length));
-		return KRB5KRB_AP_ERR_MODIFIED;
-	}
-
-	p += 2;
-
-	vnum = RSVAL(p, 0); p += 2;
-
-	/* FIXME: According to standard there is only one type of reply */	
-	if (vnum != KRB5_KPASSWD_VERS_SETPW && 
-	    vnum != KRB5_KPASSWD_VERS_SETPW_ALT && 
-	    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 = (char *)clearresult.data;
-	
-	res_code = RSVAL(p, 0);
-	
-	free(clearresult.data);
-
-	if ((res_code < KRB5_KPASSWD_SUCCESS) || 
-	    (res_code > KRB5_KPASSWD_ETYPE_NOSUPP)) {
-		return KRB5KRB_AP_ERR_MODIFIED;
-	}
-
-	if (res_code == KRB5_KPASSWD_SUCCESS) {
-		return 0;
-	} else {
-		const char *errstr;
-		setpw_result_code_string(context, res_code, &errstr);
-		DEBUG(1, ("Error changing password: %s (%d)\n", errstr, res_code));
-
-		return kpasswd_err_to_krb5_err(res_code);
-	}
-}
-
-static ADS_STATUS do_krb5_kpasswd_request(krb5_context context,
-					  const char *kdc_host,
-					  uint16 pversion,
-					  krb5_creds *credsp,
-					  const char *princ,
-					  const char *newpw)
-{
-	krb5_auth_context auth_context = NULL;
-	krb5_data ap_req, chpw_req, chpw_rep;
-	int ret, sock;
-	socklen_t addr_len;
-	struct sockaddr_storage remote_addr, local_addr;
-	struct sockaddr_storage addr;
-	krb5_address local_kaddr, remote_kaddr;
-	bool use_tcp = False;
-
-
-	if (!interpret_string_addr(&addr, kdc_host, 0)) {
-	}
-
-	ret = krb5_mk_req_extended(context, &auth_context, AP_OPTS_USE_SUBKEY,
-				   NULL, credsp, &ap_req);
-	if (ret) {
-		DEBUG(1,("krb5_mk_req_extended failed (%s)\n", error_message(ret)));
-		return ADS_ERROR_KRB5(ret);
-	}
-
-	do {
-
-		if (!use_tcp) {
-
-			sock = open_udp_socket(kdc_host, DEFAULT_KPASSWD_PORT);
-			if (sock == -1) {
-				int rc = errno;
-				SAFE_FREE(ap_req.data);
-				krb5_auth_con_free(context, auth_context);
-				DEBUG(1,("failed to open kpasswd socket to %s "
-					 "(%s)\n", kdc_host, strerror(errno)));
-				return ADS_ERROR_SYSTEM(rc);
-			}
-		} else {
-			NTSTATUS status;
-			status = open_socket_out(&addr, DEFAULT_KPASSWD_PORT,
-						 LONG_CONNECT_TIMEOUT, &sock);
-			if (!NT_STATUS_IS_OK(status)) {
-				SAFE_FREE(ap_req.data);
-				krb5_auth_con_free(context, auth_context);
-				DEBUG(1,("failed to open kpasswd socket to %s "
-					 "(%s)\n", kdc_host,
-					 nt_errstr(status)));
-				return ADS_ERROR_NT(status);
-			}
-		}
-
-		addr_len = sizeof(remote_addr);
-		if (getpeername(sock, (struct sockaddr *)&remote_addr, &addr_len) != 0) {
-			close(sock);
-			SAFE_FREE(ap_req.data);
-			krb5_auth_con_free(context, auth_context);
-			DEBUG(1,("getpeername() failed (%s)\n", error_message(errno)));
-			return ADS_ERROR_SYSTEM(errno);
-		}
-		addr_len = sizeof(local_addr);
-		if (getsockname(sock, (struct sockaddr *)&local_addr, &addr_len) != 0) {
-			close(sock);
-			SAFE_FREE(ap_req.data);
-			krb5_auth_con_free(context, auth_context);
-			DEBUG(1,("getsockname() failed (%s)\n", error_message(errno)));
-			return ADS_ERROR_SYSTEM(errno);
-		}
-		if (!setup_kaddr(&remote_kaddr, &remote_addr) ||
-				!setup_kaddr(&local_kaddr, &local_addr)) {
-			DEBUG(1,("do_krb5_kpasswd_request: "
-				"Failed to setup addresses.\n"));
-			close(sock);
-			SAFE_FREE(ap_req.data);
-			krb5_auth_con_free(context, auth_context);
-			errno = EINVAL;
-			return ADS_ERROR_SYSTEM(EINVAL);
-		}
-
-		ret = krb5_auth_con_setaddrs(context, auth_context, &local_kaddr, NULL);
-		if (ret) {
-			close(sock);
-			SAFE_FREE(ap_req.data);
-			krb5_auth_con_free(context, auth_context);
-			DEBUG(1,("krb5_auth_con_setaddrs failed (%s)\n", error_message(ret)));
-			return ADS_ERROR_KRB5(ret);
-		}
-
-		ret = build_kpasswd_request(pversion, context, auth_context, &ap_req,
-					  princ, newpw, use_tcp, &chpw_req);
-		if (ret) {
-			close(sock);
-			SAFE_FREE(ap_req.data);
-			krb5_auth_con_free(context, auth_context);
-			DEBUG(1,("build_setpw_request failed (%s)\n", error_message(ret)));
-			return ADS_ERROR_KRB5(ret);
-		}
-
-		ret = write(sock, chpw_req.data, chpw_req.length); 
 
-		if (ret != chpw_req.length) {
-			close(sock);
-			SAFE_FREE(chpw_req.data);
-			SAFE_FREE(ap_req.data);
-			krb5_auth_con_free(context, auth_context);
-			DEBUG(1,("send of chpw failed (%s)\n", strerror(errno)));
-			return ADS_ERROR_SYSTEM(errno);
-		}
-	
-		SAFE_FREE(chpw_req.data);
-	
-		chpw_rep.length = 1500;
-		chpw_rep.data = (char *) SMB_MALLOC(chpw_rep.length);
-		if (!chpw_rep.data) {
-			close(sock);
-			SAFE_FREE(ap_req.data);
-			krb5_auth_con_free(context, auth_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);
-			SAFE_FREE(chpw_rep.data);
-			SAFE_FREE(ap_req.data);
-			krb5_auth_con_free(context, auth_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) {
-			SAFE_FREE(chpw_rep.data);
-			SAFE_FREE(ap_req.data);
-			krb5_auth_con_free(context, auth_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, use_tcp, auth_context, &chpw_rep);
-		SAFE_FREE(chpw_rep.data);
-	
-		if (ret) {
-			
-			if (ret == KRB5KRB_ERR_RESPONSE_TOO_BIG && !use_tcp) {
-				DEBUG(5, ("Trying setpw with TCP!!!\n"));
-				use_tcp = True;
-				continue;
-			}
-
-			SAFE_FREE(ap_req.data);
-			krb5_auth_con_free(context, auth_context);
-			DEBUG(1,("parse_setpw_reply failed (%s)\n", 
-				 error_message(ret)));
-			return ADS_ERROR_KRB5(ret);
-		}
-	
-		SAFE_FREE(ap_req.data);
-		krb5_auth_con_free(context, auth_context);
-	} while ( ret );
-
-	return ADS_SUCCESS;
-}
-
-ADS_STATUS ads_krb5_set_password(const char *kdc_host, const char *princ, 
+ADS_STATUS ads_krb5_set_password(const char *kdc_host, const char *principal,
 				 const char *newpw, int time_offset)
 {
 
 	ADS_STATUS aret;
 	krb5_error_code ret = 0;
 	krb5_context context = NULL;
-	char *realm = NULL;
-	unsigned int realm_len = 0;
-	krb5_creds creds, *credsp = NULL;
+	krb5_principal princ = NULL;
 	krb5_ccache ccache = NULL;
+	int result_code;
+	krb5_data result_code_string = { 0 };
+	krb5_data result_string = { 0 };
 
-	ZERO_STRUCT(creds);
-	
 	initialize_krb5_error_table();
 	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 (principal) {
+		ret = smb_krb5_parse_name(context, principal, &princ);
+		if (ret) {
+			krb5_free_context(context);
+			DEBUG(1, ("Failed to parse %s (%s)\n", principal,
+				  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_principal(context, princ);
 	        krb5_free_context(context);
 		DEBUG(1,("Failed to get default creds (%s)\n", error_message(ret)));
 		return ADS_ERROR_KRB5(ret);
 	}
 
-	ret = krb5_cc_get_principal(context, ccache, &creds.client);
+	ret = krb5_set_password_using_ccache(context, ccache, newpw, princ,
+					     &result_code,
+					     &result_code_string,
+					     &result_string);
 	if (ret) {
-		krb5_cc_close(context, ccache);
-                krb5_free_context(context);
-		DEBUG(1,("Failed to get principal from ccache (%s)\n",
-			 error_message(ret)));
-		return ADS_ERROR_KRB5(ret);
+		DEBUG(1, ("krb5_set_password failed (%s)\n", error_message(ret)));
+		aret = ADS_ERROR_KRB5(ret);
+		goto done;
 	}
 
-	realm = smb_krb5_principal_get_realm(context, creds.client);
-	realm_len = strlen(realm);
-	ret = krb5_build_principal(context,
-				   &creds.server,
-				   realm_len,
-				   realm, "kadmin", "changepw", NULL);
-	free(realm);
-	ret = krb5_get_credentials(context, 0, ccache, &creds, &credsp);
-	if (ret) {
-		krb5_cc_close(context, ccache);
-	        krb5_free_principal(context, creds.client);
-	        krb5_free_principal(context, creds.server);
-	        krb5_free_context(context);
-		DEBUG(1,("krb5_build_prinipal_ext (%s)\n", error_message(ret)));
-		return ADS_ERROR_KRB5(ret);
+	if (result_code != KRB5_KPASSWD_SUCCESS) {
+		ret = kpasswd_err_to_krb5_err(result_code);
+		DEBUG(1, ("krb5_set_password failed (%s)\n", error_message(ret)));
+		aret = ADS_ERROR_KRB5(ret);
+		goto done;
 	}
-	
-	ret = krb5_get_credentials(context, 0, ccache, &creds, &credsp); 
-	if (ret) {
-		krb5_cc_close(context, ccache);
-	        krb5_free_principal(context, creds.client);
-	        krb5_free_principal(context, creds.server);
-	        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 ... */
 
-	aret = do_krb5_kpasswd_request(context, kdc_host,
-				       KRB5_KPASSWD_VERS_SETPW,
-				       credsp, princ, newpw);
+	aret = ADS_SUCCESS;
 
-	krb5_free_creds(context, credsp);
-	krb5_free_principal(context, creds.client);
-        krb5_free_principal(context, creds.server);
+done:
+	kerberos_free_data_contents(context, &result_code_string);
+	kerberos_free_data_contents(context, &result_string);
+	krb5_free_principal(context, princ);
 	krb5_cc_close(context, ccache);
 	krb5_free_context(context);
 
@@ -683,7 +168,10 @@ static ADS_STATUS ads_krb5_chg_password(const char *kdc_host,
     krb5_get_init_creds_opt opts;
     krb5_creds creds;
     char *chpw_princ = NULL, *password;
-    char *realm = NULL;
+    const char *realm = NULL;
+    int result_code;
+    krb5_data result_code_string = { 0 };
+    krb5_data result_string = { 0 };
 
     initialize_krb5_error_table();
     ret = krb5_init_context(&context);
@@ -734,10 +222,26 @@ static ADS_STATUS ads_krb5_chg_password(const char *kdc_host,
 	return ADS_ERROR_KRB5(ret);
     }
 
-    aret = do_krb5_kpasswd_request(context, kdc_host,
-				   KRB5_KPASSWD_VERS_CHANGEPW,
-				   &creds, principal, newpw);
+    ret = krb5_change_password(context, &creds, newpw, &result_code,
+			       &result_code_string, &result_string);
+    if (ret) {
+	DEBUG(1, ("krb5_change_password failed (%s)\n", error_message(ret)));
+	aret = ADS_ERROR_KRB5(ret);
+	goto done;
+    }
+
+    if (result_code != KRB5_KPASSWD_SUCCESS) {
+	ret = kpasswd_err_to_krb5_err(result_code);
+	DEBUG(1, ("krb5_change_password failed (%s)\n", error_message(ret)));
+	aret = ADS_ERROR_KRB5(ret);
+	goto done;
+    }
+
+    aret = ADS_SUCCESS;
 
+done:
+    kerberos_free_data_contents(context, &result_code_string);
+    kerberos_free_data_contents(context, &result_string);
     krb5_free_principal(context, princ);
     krb5_free_context(context);