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

2 files changed, 4 insertions, 159 deletions

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);