Move DRSUAPI per-attribute decryption into a common file

This file (contining metze's decryption routines) is now also be used by
Samba3's DRSUAPI implementation

Andrew Bartlett

9 files changed, 249 insertions, 347 deletions

diff --git a/libcli/drsuapi/config.mk b/libcli/drsuapi/config.mk
new file mode 100644
index 0000000000..cb002ca3dc
--- /dev/null
+++ b/libcli/drsuapi/config.mk
@@ -0,0 +1,8 @@
+[SUBSYSTEM::LIBCLI_DRSUAPI]
+PUBLIC_DEPENDENCIES = \
+		LIBCLI_AUTH
+
+LIBCLI_DRSUAPI_OBJ_FILES = $(addprefix $(libclicommonsrcdir)/drsuapi/, \
+		repl_decrypt.o)
+
+PUBLIC_HEADERS += ../libcli/drsuapi/drsuapi.h
diff --git a/libcli/drsuapi/drsuapi.h b/libcli/drsuapi/drsuapi.h
new file mode 100644
index 0000000000..b95350779a
--- /dev/null
+++ b/libcli/drsuapi/drsuapi.h
@@ -0,0 +1,33 @@
+/* 
+   Unix SMB/CIFS mplementation.
+   Helper functions for applying replicated objects
+   
+   Copyright (C) Stefan Metzmacher <metze@samba.org> 2007
+    
+   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/>.
+   
+*/
+
+WERROR drsuapi_decrypt_attribute_value(TALLOC_CTX *mem_ctx,
+				       const DATA_BLOB *gensec_skey,
+				       bool rid_crypt,
+				       uint32_t rid,
+				       DATA_BLOB *in,
+				       DATA_BLOB *out);
+
+WERROR drsuapi_decrypt_attribute(TALLOC_CTX *mem_ctx, 
+				 const DATA_BLOB *gensec_skey,
+				 uint32_t rid,
+				 struct drsuapi_DsReplicaAttribute *attr);
+
diff --git a/libcli/drsuapi/repl_decrypt.c b/libcli/drsuapi/repl_decrypt.c
new file mode 100644
index 0000000000..9d7c1b6acf
--- /dev/null
+++ b/libcli/drsuapi/repl_decrypt.c
@@ -0,0 +1,188 @@
+/* 
+   Unix SMB/CIFS mplementation.
+   Helper functions for applying replicated objects
+   
+   Copyright (C) Stefan Metzmacher <metze@samba.org> 2007
+    
+   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 "../lib/util/dlinklist.h"
+#include "librpc/gen_ndr/ndr_misc.h"
+#include "librpc/gen_ndr/ndr_drsuapi.h"
+#include "librpc/gen_ndr/ndr_drsblobs.h"
+#include "../lib/crypto/crypto.h"
+#include "../libcli/drsuapi/drsuapi.h"
+#include "libcli/auth/libcli_auth.h"
+
+WERROR drsuapi_decrypt_attribute_value(TALLOC_CTX *mem_ctx,
+				       const DATA_BLOB *gensec_skey,
+				       bool rid_crypt,
+				       uint32_t rid,
+				       DATA_BLOB *in,
+				       DATA_BLOB *out)
+{
+	DATA_BLOB confounder;
+	DATA_BLOB enc_buffer;
+
+	struct MD5Context md5;
+	uint8_t _enc_key[16];
+	DATA_BLOB enc_key;
+
+	DATA_BLOB dec_buffer;
+
+	uint32_t crc32_given;
+	uint32_t crc32_calc;
+	DATA_BLOB checked_buffer;
+
+	DATA_BLOB plain_buffer;
+
+	/*
+	 * users with rid == 0 should not exist
+	 */
+	if (rid_crypt && rid == 0) {
+		return WERR_DS_DRA_INVALID_PARAMETER;
+	}
+
+	/* 
+	 * the first 16 bytes at the beginning are the confounder
+	 * followed by the 4 byte crc32 checksum
+	 */
+	if (in->length < 20) {
+		return WERR_DS_DRA_INVALID_PARAMETER;
+	}
+	confounder = data_blob_const(in->data, 16);
+	enc_buffer = data_blob_const(in->data + 16, in->length - 16);
+
+	/* 
+	 * build the encryption key md5 over the session key followed
+	 * by the confounder
+	 * 
+	 * here the gensec session key is used and
+	 * not the dcerpc ncacn_ip_tcp "SystemLibraryDTC" key!
+	 */
+	enc_key = data_blob_const(_enc_key, sizeof(_enc_key));
+	MD5Init(&md5);
+	MD5Update(&md5, gensec_skey->data, gensec_skey->length);
+	MD5Update(&md5, confounder.data, confounder.length);
+	MD5Final(enc_key.data, &md5);
+
+	/*
+	 * copy the encrypted buffer part and 
+	 * decrypt it using the created encryption key using arcfour
+	 */
+	dec_buffer = data_blob_const(enc_buffer.data, enc_buffer.length);
+	arcfour_crypt_blob(dec_buffer.data, dec_buffer.length, &enc_key);
+
+	/* 
+	 * the first 4 byte are the crc32 checksum
+	 * of the remaining bytes
+	 */
+	crc32_given = IVAL(dec_buffer.data, 0);
+	crc32_calc = crc32_calc_buffer(dec_buffer.data + 4 , dec_buffer.length - 4);
+	if (crc32_given != crc32_calc) {
+		return WERR_SEC_E_DECRYPT_FAILURE;
+	}
+	checked_buffer = data_blob_const(dec_buffer.data + 4, dec_buffer.length - 4);
+
+	plain_buffer = data_blob_talloc(mem_ctx, checked_buffer.data, checked_buffer.length);
+	W_ERROR_HAVE_NO_MEMORY(plain_buffer.data);
+
+	/*
+	 * The following rid_crypt obfuscation isn't session specific
+	 * and not really needed here, because we allways know the rid of the
+	 * user account.
+	 *
+	 * some attributes with this 'additional encryption' include
+	 * dBCSPwd, unicodePwd, ntPwdHistory, lmPwdHistory
+	 *
+	 * But for the rest of samba it's easier when we remove this static
+	 * obfuscation here
+	 */
+	if (rid_crypt) {
+		uint32_t i, num_hashes;
+
+		if ((checked_buffer.length % 16) != 0) {
+			return WERR_DS_DRA_INVALID_PARAMETER;
+		}
+
+		num_hashes = plain_buffer.length / 16;
+		for (i = 0; i < num_hashes; i++) {
+			uint32_t offset = i * 16;
+			sam_rid_crypt(rid, checked_buffer.data + offset, plain_buffer.data + offset, 0);
+		}
+	}
+
+	*out = plain_buffer;
+	return WERR_OK;
+}
+
+WERROR drsuapi_decrypt_attribute(TALLOC_CTX *mem_ctx, 
+				 const DATA_BLOB *gensec_skey,
+				 uint32_t rid,
+				 struct drsuapi_DsReplicaAttribute *attr)
+{
+	WERROR status;
+	DATA_BLOB *enc_data;
+	DATA_BLOB plain_data;
+	bool rid_crypt = false;
+
+	if (attr->value_ctr.num_values == 0) {
+		return WERR_OK;
+	}
+
+	switch (attr->attid) {
+	case DRSUAPI_ATTRIBUTE_dBCSPwd:
+	case DRSUAPI_ATTRIBUTE_unicodePwd:
+	case DRSUAPI_ATTRIBUTE_ntPwdHistory:
+	case DRSUAPI_ATTRIBUTE_lmPwdHistory:
+		rid_crypt = true;
+		break;
+	case DRSUAPI_ATTRIBUTE_supplementalCredentials:
+	case DRSUAPI_ATTRIBUTE_priorValue:
+	case DRSUAPI_ATTRIBUTE_currentValue:
+	case DRSUAPI_ATTRIBUTE_trustAuthOutgoing:
+	case DRSUAPI_ATTRIBUTE_trustAuthIncoming:
+	case DRSUAPI_ATTRIBUTE_initialAuthOutgoing:
+	case DRSUAPI_ATTRIBUTE_initialAuthIncoming:
+		break;
+	default:
+		return WERR_OK;
+	}
+
+	if (attr->value_ctr.num_values > 1) {
+		return WERR_DS_DRA_INVALID_PARAMETER;
+	}
+
+	if (!attr->value_ctr.values[0].blob) {
+		return WERR_DS_DRA_INVALID_PARAMETER;
+	}
+
+	enc_data	= attr->value_ctr.values[0].blob;
+
+	status = drsuapi_decrypt_attribute_value(mem_ctx,
+						 gensec_skey,
+						 rid_crypt,
+						 rid,
+						 enc_data,
+						 &plain_data);
+	W_ERROR_NOT_OK_RETURN(status);
+
+	talloc_free(attr->value_ctr.values[0].blob->data);
+	*attr->value_ctr.values[0].blob = plain_data;
+
+	return WERR_OK;
+}
diff --git a/source3/libnet/libnet_dssync.c b/source3/libnet/libnet_dssync.c
index 746b09635d..59feac2495 100644
--- a/source3/libnet/libnet_dssync.c
+++ b/source3/libnet/libnet_dssync.c
@@ -22,6 +22,7 @@
 
 #include "includes.h"
 #include "libnet/libnet.h"
+#include "../libcli/drsuapi/drsuapi.h"
 
 /****************************************************************
 ****************************************************************/
@@ -61,49 +62,6 @@ NTSTATUS libnet_dssync_init_context(TALLOC_CTX *mem_ctx,
 /****************************************************************
 ****************************************************************/
 
-static DATA_BLOB *decrypt_attr_val(TALLOC_CTX *mem_ctx,
-				   DATA_BLOB *session_key,
-				   uint32_t rid,
-				   enum drsuapi_DsAttributeId id,
-				   DATA_BLOB *raw_data)
-{
-	bool rcrypt = false;
-	DATA_BLOB out_data;
-
-	ZERO_STRUCT(out_data);
-
-	switch (id) {
-		case DRSUAPI_ATTRIBUTE_dBCSPwd:
-		case DRSUAPI_ATTRIBUTE_unicodePwd:
-		case DRSUAPI_ATTRIBUTE_ntPwdHistory:
-		case DRSUAPI_ATTRIBUTE_lmPwdHistory:
-			rcrypt	= true;
-			break;
-		case DRSUAPI_ATTRIBUTE_supplementalCredentials:
-		case DRSUAPI_ATTRIBUTE_priorValue:
-		case DRSUAPI_ATTRIBUTE_currentValue:
-		case DRSUAPI_ATTRIBUTE_trustAuthOutgoing:
-		case DRSUAPI_ATTRIBUTE_trustAuthIncoming:
-		case DRSUAPI_ATTRIBUTE_initialAuthOutgoing:
-		case DRSUAPI_ATTRIBUTE_initialAuthIncoming:
-			break;
-		default:
-			return raw_data;
-	}
-
-	out_data = decrypt_drsuapi_blob(mem_ctx, session_key, rcrypt,
-					  rid, raw_data);
-
-	if (out_data.length) {
-		return (DATA_BLOB *)talloc_memdup(mem_ctx, &out_data, sizeof(DATA_BLOB));
-	}
-
-	return raw_data;
-}
-
-/****************************************************************
-****************************************************************/
-
 static void parse_obj_identifier(struct drsuapi_DsReplicaObjectIdentifier *id,
 				 uint32_t *rid)
 {
@@ -121,30 +79,6 @@ static void parse_obj_identifier(struct drsuapi_DsReplicaObjectIdentifier *id,
 /****************************************************************
 ****************************************************************/
 
-static void parse_obj_attribute(TALLOC_CTX *mem_ctx,
-				DATA_BLOB *session_key,
-				uint32_t rid,
-				struct drsuapi_DsReplicaAttribute *attr)
-{
-	int i = 0;
-
-	for (i=0; i<attr->value_ctr.num_values; i++) {
-
-		DATA_BLOB *plain_data = NULL;
-
-		plain_data = decrypt_attr_val(mem_ctx,
-					      session_key,
-					      rid,
-					      attr->attid,
-					      attr->value_ctr.values[i].blob);
-
-		attr->value_ctr.values[i].blob = plain_data;
-	}
-}
-
-/****************************************************************
-****************************************************************/
-
 static void libnet_dssync_decrypt_attributes(TALLOC_CTX *mem_ctx,
 					     DATA_BLOB *session_key,
 					     struct drsuapi_DsReplicaObjectListItemEx *cur)
@@ -170,10 +104,10 @@ static void libnet_dssync_decrypt_attributes(TALLOC_CTX *mem_ctx,
 				continue;
 			}
 
-			parse_obj_attribute(mem_ctx,
-					    session_key,
-					    rid,
-					    attr);
+			drsuapi_decrypt_attribute(mem_ctx,
+						  session_key,
+						  rid,
+						  attr);
 		}
 	}
 }
diff --git a/source4/dsdb/config.mk b/source4/dsdb/config.mk
index 8d1647953f..0895a1dd86 100644
--- a/source4/dsdb/config.mk
+++ b/source4/dsdb/config.mk
@@ -8,7 +8,8 @@ mkinclude samdb/ldb_modules/config.mk
 PUBLIC_DEPENDENCIES = HEIMDAL_KRB5 
 PRIVATE_DEPENDENCIES = LIBNDR NDR_DRSUAPI NDR_DRSBLOBS NSS_WRAPPER \
 					   auth_system_session LDAP_ENCODE LIBCLI_AUTH LIBNDR \
-					   SAMDB_SCHEMA LDB_WRAP SAMDB_COMMON
+					   SAMDB_SCHEMA LDB_WRAP SAMDB_COMMON \
+						LIBCLI_DRSUAPI
 
 
 SAMDB_OBJ_FILES = $(addprefix $(dsdbsrcdir)/, \
diff --git a/source4/dsdb/repl/replicated_objects.c b/source4/dsdb/repl/replicated_objects.c
index 560f75da7a..78af3c8f6d 100644
--- a/source4/dsdb/repl/replicated_objects.c
+++ b/source4/dsdb/repl/replicated_objects.c
@@ -27,166 +27,10 @@
 #include "librpc/gen_ndr/ndr_drsuapi.h"
 #include "librpc/gen_ndr/ndr_drsblobs.h"
 #include "../lib/crypto/crypto.h"
+#include "../libcli/drsuapi/drsuapi.h"
 #include "libcli/auth/libcli_auth.h"
 #include "param/param.h"
 
-static WERROR dsdb_decrypt_attribute_value(TALLOC_CTX *mem_ctx,
-					   const DATA_BLOB *gensec_skey,
-					   bool rid_crypt,
-					   uint32_t rid,
-					   DATA_BLOB *in,
-					   DATA_BLOB *out)
-{
-	DATA_BLOB confounder;
-	DATA_BLOB enc_buffer;
-
-	struct MD5Context md5;
-	uint8_t _enc_key[16];
-	DATA_BLOB enc_key;
-
-	DATA_BLOB dec_buffer;
-
-	uint32_t crc32_given;
-	uint32_t crc32_calc;
-	DATA_BLOB checked_buffer;
-
-	DATA_BLOB plain_buffer;
-
-	/*
-	 * users with rid == 0 should not exist
-	 */
-	if (rid_crypt && rid == 0) {
-		return WERR_DS_DRA_INVALID_PARAMETER;
-	}
-
-	/* 
-	 * the first 16 bytes at the beginning are the confounder
-	 * followed by the 4 byte crc32 checksum
-	 */
-	if (in->length < 20) {
-		return WERR_DS_DRA_INVALID_PARAMETER;
-	}
-	confounder = data_blob_const(in->data, 16);
-	enc_buffer = data_blob_const(in->data + 16, in->length - 16);
-
-	/* 
-	 * build the encryption key md5 over the session key followed
-	 * by the confounder
-	 * 
-	 * here the gensec session key is used and
-	 * not the dcerpc ncacn_ip_tcp "SystemLibraryDTC" key!
-	 */
-	enc_key = data_blob_const(_enc_key, sizeof(_enc_key));
-	MD5Init(&md5);
-	MD5Update(&md5, gensec_skey->data, gensec_skey->length);
-	MD5Update(&md5, confounder.data, confounder.length);
-	MD5Final(enc_key.data, &md5);
-
-	/*
-	 * copy the encrypted buffer part and 
-	 * decrypt it using the created encryption key using arcfour
-	 */
-	dec_buffer = data_blob_const(enc_buffer.data, enc_buffer.length);
-	arcfour_crypt_blob(dec_buffer.data, dec_buffer.length, &enc_key);
-
-	/* 
-	 * the first 4 byte are the crc32 checksum
-	 * of the remaining bytes
-	 */
-	crc32_given = IVAL(dec_buffer.data, 0);
-	crc32_calc = crc32_calc_buffer(dec_buffer.data + 4 , dec_buffer.length - 4);
-	if (crc32_given != crc32_calc) {
-		return WERR_SEC_E_DECRYPT_FAILURE;
-	}
-	checked_buffer = data_blob_const(dec_buffer.data + 4, dec_buffer.length - 4);
-
-	plain_buffer = data_blob_talloc(mem_ctx, checked_buffer.data, checked_buffer.length);
-	W_ERROR_HAVE_NO_MEMORY(plain_buffer.data);
-
-	/*
-	 * The following rid_crypt obfuscation isn't session specific
-	 * and not really needed here, because we allways know the rid of the
-	 * user account.
-	 *
-	 * But for the rest of samba it's easier when we remove this static
-	 * obfuscation here
-	 */
-	if (rid_crypt) {
-		uint32_t i, num_hashes;
-
-		if ((checked_buffer.length % 16) != 0) {
-			return WERR_DS_DRA_INVALID_PARAMETER;
-		}
-
-		num_hashes = plain_buffer.length / 16;
-		for (i = 0; i < num_hashes; i++) {
-			uint32_t offset = i * 16;
-			sam_rid_crypt(rid, checked_buffer.data + offset, plain_buffer.data + offset, 0);
-		}
-	}
-
-	*out = plain_buffer;
-	return WERR_OK;
-}
-
-static WERROR dsdb_decrypt_attribute(const DATA_BLOB *gensec_skey,
-				     uint32_t rid,
-				     struct drsuapi_DsReplicaAttribute *attr)
-{
-	WERROR status;
-	TALLOC_CTX *mem_ctx;
-	DATA_BLOB *enc_data;
-	DATA_BLOB plain_data;
-	bool rid_crypt = false;
-
-	if (attr->value_ctr.num_values == 0) {
-		return WERR_OK;
-	}
-
-	switch (attr->attid) {
-	case DRSUAPI_ATTRIBUTE_dBCSPwd:
-	case DRSUAPI_ATTRIBUTE_unicodePwd:
-	case DRSUAPI_ATTRIBUTE_ntPwdHistory:
-	case DRSUAPI_ATTRIBUTE_lmPwdHistory:
-		rid_crypt = true;
-		break;
-	case DRSUAPI_ATTRIBUTE_supplementalCredentials:
-	case DRSUAPI_ATTRIBUTE_priorValue:
-	case DRSUAPI_ATTRIBUTE_currentValue:
-	case DRSUAPI_ATTRIBUTE_trustAuthOutgoing:
-	case DRSUAPI_ATTRIBUTE_trustAuthIncoming:
-	case DRSUAPI_ATTRIBUTE_initialAuthOutgoing:
-	case DRSUAPI_ATTRIBUTE_initialAuthIncoming:
-		break;
-	default:
-		return WERR_OK;
-	}
-
-	if (attr->value_ctr.num_values > 1) {
-		return WERR_DS_DRA_INVALID_PARAMETER;
-	}
-
-	if (!attr->value_ctr.values[0].blob) {
-		return WERR_DS_DRA_INVALID_PARAMETER;
-	}
-
-	mem_ctx		= attr->value_ctr.values[0].blob;
-	enc_data	= attr->value_ctr.values[0].blob;
-
-	status = dsdb_decrypt_attribute_value(mem_ctx,
-					      gensec_skey,
-					      rid_crypt,
-					      rid,
-					      enc_data,
-					      &plain_data);
-	W_ERROR_NOT_OK_RETURN(status);
-
-	talloc_free(attr->value_ctr.values[0].blob->data);
-	*attr->value_ctr.values[0].blob = plain_data;
-
-	return WERR_OK;
-}
-
 static WERROR dsdb_convert_object(struct ldb_context *ldb,
 				  const struct dsdb_schema *schema,
 				  struct dsdb_extended_replicated_objects *ctr,
@@ -279,7 +123,7 @@ static WERROR dsdb_convert_object(struct ldb_context *ldb,
 		m = &md->ctr.ctr1.array[i];
 		e = &msg->elements[i];
 
-		status = dsdb_decrypt_attribute(gensec_skey, rid, a);
+		status = drsuapi_decrypt_attribute(a->value_ctr.values[0].blob, gensec_skey, rid, a);
 		W_ERROR_NOT_OK_RETURN(status);
 
 		status = dsdb_attribute_drsuapi_to_ldb(ldb, schema, a, msg->elements, e);
diff --git a/source4/main.mk b/source4/main.mk
index f4314e3742..c62aba742e 100644
--- a/source4/main.mk
+++ b/source4/main.mk
@@ -54,4 +54,5 @@ mkinclude ../lib/async_req/config.mk
 mkinclude ../libcli/security/config.mk
 mkinclude ../libcli/ldap/config.mk
 mkinclude ../libcli/auth/config.mk
+mkinclude ../libcli/drsuapi/config.mk
 
diff --git a/source4/torture/config.mk b/source4/torture/config.mk
index 895fef6174..bec2a064dc 100644
--- a/source4/torture/config.mk
+++ b/source4/torture/config.mk
@@ -111,7 +111,7 @@ PRIVATE_DEPENDENCIES = \
 		RPC_NDR_SRVSVC RPC_NDR_WKSSVC RPC_NDR_ROT RPC_NDR_DSSETUP \
 		RPC_NDR_REMACT RPC_NDR_OXIDRESOLVER RPC_NDR_NTSVCS WB_HELPER LIBSAMBA-NET \
 		LIBCLI_AUTH POPT_CREDENTIALS TORTURE_LDAP TORTURE_LDB TORTURE_UTIL TORTURE_RAP \
-		dcerpc_server service process_model ntvfs SERVICE_SMB RPC_NDR_BROWSER
+		dcerpc_server service process_model ntvfs SERVICE_SMB RPC_NDR_BROWSER LIBCLI_DRSUAPI
 
 torture_rpc_OBJ_FILES = $(addprefix $(torturesrcdir)/rpc/, \
 		join.o lsa.o lsa_lookup.o session_key.o echo.o dfs.o drsuapi.o \
diff --git a/source4/torture/rpc/dssync.c b/source4/torture/rpc/dssync.c
index 1aaf914ceb..b47564cc91 100644
--- a/source4/torture/rpc/dssync.c
+++ b/source4/torture/rpc/dssync.c
@@ -30,6 +30,7 @@
 #include "torture/ldap/proto.h"
 #include "libcli/auth/libcli_auth.h"
 #include "../lib/crypto/crypto.h"
+#include "../libcli/drsuapi/drsuapi.h"
 #include "auth/credentials/credentials.h"
 #include "libcli/auth/libcli_auth.h"
 #include "auth/gensec/gensec.h"
@@ -338,119 +339,6 @@ static bool test_GetInfo(struct torture_context *tctx, struct DsSyncTest *ctx)
 	return ret;
 }
 
-static DATA_BLOB decrypt_blob(TALLOC_CTX *mem_ctx,
-			      const DATA_BLOB *gensec_skey,
-			      bool rcrypt,
-			      struct drsuapi_DsReplicaObjectIdentifier *id,
-			      uint32_t rid,
-			      const DATA_BLOB *buffer)
-{
-	DATA_BLOB confounder;
-	DATA_BLOB enc_buffer;
-
-	struct MD5Context md5;
-	uint8_t _enc_key[16];
-	DATA_BLOB enc_key;
-
-	DATA_BLOB dec_buffer;
-
-	uint32_t crc32_given;
-	uint32_t crc32_calc;
-	DATA_BLOB checked_buffer;
-
-	DATA_BLOB plain_buffer;
-
-	/*
-	 * the combination "c[3] s[1] e[1] d[0]..."
-	 * was successful!!!!!!!!!!!!!!!!!!!!!!!!!!
-	 */
-
-	/* 
-	 * the first 16 bytes at the beginning are the confounder
-	 * followed by the 4 byte crc32 checksum
-	 */
-	if (buffer->length < 20) {
-		return data_blob_const(NULL, 0);
-	}
-	confounder = data_blob_const(buffer->data, 16);
-	enc_buffer = data_blob_const(buffer->data + 16, buffer->length - 16);
-
-	/* 
-	 * build the encryption key md5 over the session key followed
-	 * by the confounder
-	 * 
-	 * here the gensec session key is used and
-	 * not the dcerpc ncacn_ip_tcp "SystemLibraryDTC" key!
-	 */
-	enc_key = data_blob_const(_enc_key, sizeof(_enc_key));
-	MD5Init(&md5);
-	MD5Update(&md5, gensec_skey->data, gensec_skey->length);
-	MD5Update(&md5, confounder.data, confounder.length);
-	MD5Final(enc_key.data, &md5);
-
-	/*
-	 * copy the encrypted buffer part and 
-	 * decrypt it using the created encryption key using arcfour
-	 */
-	dec_buffer = data_blob_talloc(mem_ctx, enc_buffer.data, enc_buffer.length);
-	if (!dec_buffer.data) {
-		return data_blob_const(NULL, 0);
-	}
-	arcfour_crypt_blob(dec_buffer.data, dec_buffer.length, &enc_key);
-
-	/* 
-	 * the first 4 byte are the crc32 checksum
-	 * of the remaining bytes
-	 */
-	crc32_given = IVAL(dec_buffer.data, 0);
-	crc32_calc = crc32_calc_buffer(dec_buffer.data + 4 , dec_buffer.length - 4);
-	if (crc32_given != crc32_calc) {
-		DEBUG(0,("CRC32: given[0x%08X] calc[0x%08X]\n",
-		      crc32_given, crc32_calc));
-		return data_blob_const(NULL, 0);
-	}
-	checked_buffer = data_blob_talloc(mem_ctx, dec_buffer.data + 4, dec_buffer.length - 4);
-	if (!checked_buffer.data) {
-		return data_blob_const(NULL, 0);
-	}
-
-	/*
-	 * some attributes seem to be in a usable form after this decryption
-	 * (supplementalCredentials, priorValue, currentValue, trustAuthOutgoing,
-	 *  trustAuthIncoming, initialAuthOutgoing, initialAuthIncoming)
-	 * At least supplementalCredentials contains plaintext
-	 * like "Primary:Kerberos" (in unicode form)
-	 *
-	 * some attributes seem to have some additional encryption
-	 * dBCSPwd, unicodePwd, ntPwdHistory, lmPwdHistory
-	 *
-	 * it's the sam_rid_crypt() function, as the value is constant,
-	 * so it doesn't depend on sessionkeys.
-	 */
-	if (rcrypt) {
-		uint32_t i, num_hashes;
-
-		if ((checked_buffer.length % 16) != 0) {
-			return data_blob_const(NULL, 0);
-		}
-
-		plain_buffer = data_blob_talloc(mem_ctx, checked_buffer.data, checked_buffer.length);
-		if (!plain_buffer.data) {
-			return data_blob_const(NULL, 0);
-		}
-			
-		num_hashes = plain_buffer.length / 16;
-		for (i = 0; i < num_hashes; i++) {
-			uint32_t offset = i * 16;
-			sam_rid_crypt(rid, checked_buffer.data + offset, plain_buffer.data + offset, 0);
-		}
-	} else {
-		plain_buffer = checked_buffer;
-	}
-
-	return plain_buffer;
-}
-
 static void test_analyse_objects(struct torture_context *tctx, 
 				 struct DsSyncTest *ctx,
 				 const DATA_BLOB *gensec_skey,
@@ -481,6 +369,7 @@ static void test_analyse_objects(struct torture_context *tctx,
 		}
 
 		for (i=0; i < cur->object.attribute_ctr.num_attributes; i++) {
+			WERROR werr;
 			const char *name = NULL;
 			bool rcrypt = false;
 			DATA_BLOB *enc_data = NULL;
@@ -549,9 +438,13 @@ static void test_analyse_objects(struct torture_context *tctx,
 			enc_data = attr->value_ctr.values[0].blob;
 			ZERO_STRUCT(plain_data);
 
-			plain_data = decrypt_blob(ctx, gensec_skey, rcrypt,
-						  cur->object.identifier, rid,
-						  enc_data);
+			werr = drsuapi_decrypt_attribute_value(ctx, gensec_skey, rcrypt,
+							       rid,
+							       enc_data, &plain_data);
+			if (!W_ERROR_IS_OK(werr)) {
+				DEBUG(0, ("Failed to decrypt %s\n", name));
+				continue;
+			}
 			if (!dn_printed) {
 				object_id++;
 				DEBUG(0,("DN[%u] %s\n", object_id, dn));