s4-kdc: Add new kpasswd service Heimdal backend

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

2 files changed, 301 insertions, 1 deletions

diff --git a/source4/kdc/kpasswd-service-heimdal.c b/source4/kdc/kpasswd-service-heimdal.c
new file mode 100644
index 00000000000..12c7402bf3f
--- /dev/null
+++ b/source4/kdc/kpasswd-service-heimdal.c
@@ -0,0 +1,296 @@
+/*
+   Unix SMB/CIFS implementation.
+
+   Samba kpasswd implementation
+
+   Copyright (c) 2016      Andreas Schneider <asn@samba.org>
+
+   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 3 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, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "smbd/service_task.h"
+#include "param/param.h"
+#include "auth/auth.h"
+#include "auth/gensec/gensec.h"
+#include "kdc/kdc-server.h"
+#include "kdc/kpasswd_glue.h"
+#include "kdc/kpasswd-service.h"
+#include "kdc/kpasswd-helper.h"
+
+static krb5_error_code kpasswd_change_password(struct kdc_server *kdc,
+					       TALLOC_CTX *mem_ctx,
+					       struct auth_session_info *session_info,
+					       DATA_BLOB *password,
+					       DATA_BLOB *kpasswd_reply,
+					       const char **error_string)
+{
+	NTSTATUS status;
+	NTSTATUS result = NT_STATUS_UNSUCCESSFUL;
+	enum samPwdChangeReason reject_reason;
+	const char *reject_string = NULL;
+	struct samr_DomInfo1 *dominfo;
+	bool ok;
+
+	status = samdb_kpasswd_change_password(mem_ctx,
+					       kdc->task->lp_ctx,
+					       kdc->task->event_ctx,
+					       kdc->samdb,
+					       session_info,
+					       password,
+					       &reject_reason,
+					       &dominfo,
+					       &reject_string,
+					       &result);
+	if (!NT_STATUS_IS_OK(status)) {
+		ok = kpasswd_make_error_reply(mem_ctx,
+					      KRB5_KPASSWD_ACCESSDENIED,
+					      reject_string,
+					      kpasswd_reply);
+		if (!ok) {
+			*error_string = "Failed to create reply";
+			return KRB5_KPASSWD_HARDERROR;
+		}
+		/* We want to send an an authenticated packet. */
+		return 0;
+	}
+
+	ok = kpasswd_make_pwchange_reply(mem_ctx,
+					 result,
+					 reject_reason,
+					 dominfo,
+					 kpasswd_reply);
+	if (!ok) {
+		*error_string = "Failed to create reply";
+		return KRB5_KPASSWD_HARDERROR;
+	}
+
+	return 0;
+}
+
+static krb5_error_code kpasswd_set_password(struct kdc_server *kdc,
+					    TALLOC_CTX *mem_ctx,
+					    struct auth_session_info *session_info,
+					    DATA_BLOB *decoded_data,
+					    DATA_BLOB *kpasswd_reply,
+					    const char **error_string)
+{
+	krb5_context context = kdc->smb_krb5_context->krb5_context;
+	krb5_error_code code;
+	krb5_principal target_principal;
+	ChangePasswdDataMS chpw = {};
+	size_t chpw_len = 0;
+	DATA_BLOB password = data_blob_null;
+	enum samPwdChangeReason reject_reason = SAM_PWD_CHANGE_NO_ERROR;
+	struct samr_DomInfo1 *dominfo = NULL;
+	char *target_principal_string = NULL;
+	bool is_service_principal = false;
+	NTSTATUS status;
+	bool ok;
+
+	code = decode_ChangePasswdDataMS(decoded_data->data,
+					 decoded_data->length,
+					 &chpw,
+					 &chpw_len);
+	if (code != 0) {
+		DBG_WARNING("decode_ChangePasswdDataMS failed\n");
+		ok = kpasswd_make_error_reply(mem_ctx,
+					      KRB5_KPASSWD_MALFORMED,
+					      "Failed to decode packet",
+					      kpasswd_reply);
+		if (!ok) {
+			*error_string = "Failed to create reply";
+			return KRB5_KPASSWD_HARDERROR;
+		}
+		return 0;
+	}
+
+	ok = convert_string_talloc_handle(mem_ctx,
+					  lpcfg_iconv_handle(kdc->task->lp_ctx),
+					  CH_UTF8,
+					  CH_UTF16,
+					  (const char *)chpw.newpasswd.data,
+					  chpw.newpasswd.length,
+					  (void **)&password.data,
+					  &password.length);
+	if (!ok) {
+		free_ChangePasswdDataMS(&chpw);
+		DBG_WARNING("String conversion failed\n");
+		*error_string = "String conversion failed";
+		return KRB5_KPASSWD_HARDERROR;
+	}
+
+	if ((chpw.targname != NULL && chpw.targrealm == NULL) ||
+	    (chpw.targname == NULL && chpw.targrealm != NULL)) {
+		free_ChangePasswdDataMS(&chpw);
+		ok = kpasswd_make_error_reply(mem_ctx,
+					      KRB5_KPASSWD_MALFORMED,
+					      "Realm and principal must be "
+					      "both present, or neither present",
+					      kpasswd_reply);
+		if (!ok) {
+			*error_string = "Failed to create reply";
+			return KRB5_KPASSWD_HARDERROR;
+		}
+		return 0;
+	}
+
+	if (chpw.targname != NULL && chpw.targrealm != NULL) {
+		code = krb5_build_principal_ext(context,
+					       &target_principal,
+					       strlen(*chpw.targrealm),
+					       *chpw.targrealm,
+					       0);
+		if (code != 0) {
+			free_ChangePasswdDataMS(&chpw);
+			return kpasswd_make_error_reply(mem_ctx,
+							KRB5_KPASSWD_MALFORMED,
+							"Failed to parse principal",
+							kpasswd_reply);
+		}
+		code = copy_PrincipalName(chpw.targname,
+					  &target_principal->name);
+		if (code != 0) {
+			free_ChangePasswdDataMS(&chpw);
+			krb5_free_principal(context, target_principal);
+			return kpasswd_make_error_reply(mem_ctx,
+							KRB5_KPASSWD_MALFORMED,
+							"Failed to parse principal",
+							kpasswd_reply);
+		}
+	} else {
+		free_ChangePasswdDataMS(&chpw);
+		return kpasswd_change_password(kdc,
+					       mem_ctx,
+					       session_info,
+					       &password,
+					       kpasswd_reply,
+					       error_string);
+	}
+	free_ChangePasswdDataMS(&chpw);
+
+	if (target_principal->name.name_string.len >= 2) {
+		is_service_principal = true;
+
+		code = krb5_unparse_name_short(context,
+					       target_principal,
+					       &target_principal_string);
+	} else {
+		code = krb5_unparse_name(context,
+					 target_principal,
+					 &target_principal_string);
+	}
+	krb5_free_principal(context, target_principal);
+	if (code != 0) {
+		ok = kpasswd_make_error_reply(mem_ctx,
+					      KRB5_KPASSWD_MALFORMED,
+					      "Failed to parse principal",
+					      kpasswd_reply);
+		if (!ok) {
+			*error_string = "Failed to create reply";
+			return KRB5_KPASSWD_HARDERROR;
+		}
+	}
+
+	status = kpasswd_samdb_set_password(mem_ctx,
+					    kdc->task->event_ctx,
+					    kdc->task->lp_ctx,
+					    session_info,
+					    is_service_principal,
+					    target_principal_string,
+					    &password,
+					    &reject_reason,
+					    &dominfo);
+	if (!NT_STATUS_IS_OK(status)) {
+		DBG_ERR("kpasswd_samdb_set_password failed - %s\n",
+			nt_errstr(status));
+	}
+
+	ok = kpasswd_make_pwchange_reply(mem_ctx,
+					 status,
+					 reject_reason,
+					 dominfo,
+					 kpasswd_reply);
+	if (!ok) {
+		*error_string = "Failed to create reply";
+		return KRB5_KPASSWD_HARDERROR;
+	}
+
+	return 0;
+}
+
+krb5_error_code kpasswd_handle_request(struct kdc_server *kdc,
+				       TALLOC_CTX *mem_ctx,
+				       struct gensec_security *gensec_security,
+				       uint16_t verno,
+				       DATA_BLOB *decoded_data,
+				       DATA_BLOB *kpasswd_reply,
+				       const char **error_string)
+{
+	struct auth_session_info *session_info;
+	NTSTATUS status;
+
+	status = gensec_session_info(gensec_security,
+				     mem_ctx,
+				     &session_info);
+	if (!NT_STATUS_IS_OK(status)) {
+		*error_string = talloc_asprintf(mem_ctx,
+						"gensec_session_info failed - %s",
+						nt_errstr(status));
+		return KRB5_KPASSWD_HARDERROR;
+	}
+
+	switch(verno) {
+	case KRB5_KPASSWD_VERS_CHANGEPW: {
+		DATA_BLOB password = data_blob_null;
+		bool ok;
+
+		ok = convert_string_talloc_handle(mem_ctx,
+						  lpcfg_iconv_handle(kdc->task->lp_ctx),
+						  CH_UTF8,
+						  CH_UTF16,
+						  (const char *)decoded_data->data,
+						  decoded_data->length,
+						  (void **)&password.data,
+						  &password.length);
+		if (!ok) {
+			*error_string = "String conversion failed!";
+			DBG_WARNING("%s\n", *error_string);
+			return KRB5_KPASSWD_HARDERROR;
+		}
+
+		return kpasswd_change_password(kdc,
+					       mem_ctx,
+					       session_info,
+					       &password,
+					       kpasswd_reply,
+					       error_string);
+	}
+	case KRB5_KPASSWD_VERS_SETPW: {
+		return kpasswd_set_password(kdc,
+					    mem_ctx,
+					    session_info,
+					    decoded_data,
+					    kpasswd_reply,
+					    error_string);
+	}
+	default:
+		*error_string = talloc_asprintf(mem_ctx,
+						"Protocol version %u not supported",
+						verno);
+		return KRB5_KPASSWD_BAD_VERSION;
+	}
+
+	return 0;
+}
diff --git a/source4/kdc/wscript_build b/source4/kdc/wscript_build
index 99678ea441d..18eae904872 100755
--- a/source4/kdc/wscript_build
+++ b/source4/kdc/wscript_build
@@ -54,8 +54,12 @@ bld.SAMBA_SUBSYSTEM('KDC-SERVER',
                     ''',
                     enabled=bld.CONFIG_SET('SAMBA4_USES_HEIMDAL'))
 
+kpasswd_flavor_src = 'kpasswd-service.c kpasswd-helper.c'
+if bld.CONFIG_SET('SAMBA4_USES_HEIMDAL'):
+    kpasswd_flavor_src = kpasswd_flavor_src + ' kpasswd-service-heimdal.c'
+
 bld.SAMBA_SUBSYSTEM('KPASSWD-SERVICE',
-                    source='kpasswd-service.c kpasswd-helper.c',
+                    source=kpasswd_flavor_src,
                     includes=kdc_include,
                     deps='''
                          krb5samba