CVE-2015-5296: s3:libsmb: force signing when requiring encryption in …

…SMBC_server_internal() BUG: https://bugzilla.samba.org/show_bug.cgi?id=11536 Signed-off-by: Stefan Metzmacher <[email protected]> Reviewed-by: Jeremy Allison <[email protected]>
metze-samba · Dec 16, 2015 · aef4113 · aef4113
1 parent f8b0f7f
commit aef4113
Showing 1 changed file with 12 additions and 3 deletions.
diff --git a/source3/libsmb/libsmb_server.c b/source3/libsmb/libsmb_server.c
@@ -273,6 +273,7 @@ SMBC_server_internal(TALLOC_CTX *ctx,
 	char *newserver, *newshare;
 	int flags = 0;
 	struct smbXcli_tcon *tcon = NULL;
+	int signing_state = SMB_SIGNING_DEFAULT;
 
 	ZERO_STRUCT(c);
 	*in_cache = false;
@@ -439,14 +440,18 @@ SMBC_server_internal(TALLOC_CTX *ctx,
 		flags |= CLI_FULL_CONNECTION_USE_NT_HASH;
 	}
 
+	if (context->internal->smb_encryption_level != SMBC_ENCRYPTLEVEL_NONE) {
+		signing_state = SMB_SIGNING_REQUIRED;
+	}
+
 	if (port == 0) {
 	        if (share == NULL || *share == '\0' || is_ipc) {
 			/*
 			 * Try 139 first for IPC$
 			 */
 			status = cli_connect_nb(server_n, NULL, NBT_SMB_PORT, 0x20,
 					smbc_getNetbiosName(context),
-					SMB_SIGNING_DEFAULT, flags, &c);
+					signing_state, flags, &c);
 		}
 	}
 
@@ -456,7 +461,7 @@ SMBC_server_internal(TALLOC_CTX *ctx,
 		 */
 		status = cli_connect_nb(server_n, NULL, port, 0x20,
 					smbc_getNetbiosName(context),
-					SMB_SIGNING_DEFAULT, flags, &c);
+					signing_state, flags, &c);
 	}
 
 	if (!NT_STATUS_IS_OK(status)) {
@@ -737,6 +742,7 @@ SMBC_attr_server(TALLOC_CTX *ctx,
         ipc_srv = SMBC_find_server(ctx, context, server, "*IPC$",
                                    pp_workgroup, pp_username, pp_password);
         if (!ipc_srv) {
+		int signing_state = SMB_SIGNING_DEFAULT;
 
                 /* We didn't find a cached connection.  Get the password */
 		if (!*pp_password || (*pp_password)[0] == '\0') {
@@ -758,6 +764,9 @@ SMBC_attr_server(TALLOC_CTX *ctx,
                 if (smbc_getOptionUseCCache(context)) {
                         flags |= CLI_FULL_CONNECTION_USE_CCACHE;
                 }
+		if (context->internal->smb_encryption_level != SMBC_ENCRYPTLEVEL_NONE) {
+			signing_state = SMB_SIGNING_REQUIRED;
+		}
 
                 nt_status = cli_full_connection(&ipc_cli,
 						lp_netbios_name(), server,
@@ -766,7 +775,7 @@ SMBC_attr_server(TALLOC_CTX *ctx,
 						*pp_workgroup,
 						*pp_password,
 						flags,
-						SMB_SIGNING_DEFAULT);
+						signing_state);
                 if (! NT_STATUS_IS_OK(nt_status)) {
                         DEBUG(1,("cli_full_connection failed! (%s)\n",
                                  nt_errstr(nt_status)));