From 77d0030eff22ebed1ab4b3a124142b8fff38fb4a Mon Sep 17 00:00:00 2001
From: Vsevolod Stakhov <vsevolod@highsecure.ru>
Date: Wed, 22 May 2019 15:06:32 +0100
Subject: [PATCH] [Minor] Archives: Distinguish compressed headers and
 encrypted archives

---
 src/libmime/archives.c         |  3 ++-
 src/libmime/archives.h         |  1 +
 src/lua/lua_task.c             | 18 ++++++++++++++++++
 src/plugins/lua/mime_types.lua | 11 +++++++++--
 4 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/src/libmime/archives.c b/src/libmime/archives.c
index 9c0336ac8..c19991eb6 100644
--- a/src/libmime/archives.c
+++ b/src/libmime/archives.c
@@ -1590,7 +1590,8 @@ rspamd_7zip_read_next_section (struct rspamd_task *task,
 		 * In fact, headers are just packed, but we assume it as
 		 * encrypted to distinguish from the normal archives
 		 */
-		arch->flags |= RSPAMD_ARCHIVE_ENCRYPTED;
+		msg_debug_archive ("7zip: encoded header, needs to be uncompressed");
+		arch->flags |= RSPAMD_ARCHIVE_CANNOT_READ;
 		p = NULL; /* Cannot get anything useful */
 		break;
 	case kArchiveProperties:
diff --git a/src/libmime/archives.h b/src/libmime/archives.h
index e4e7b8b03..6abfb857a 100644
--- a/src/libmime/archives.h
+++ b/src/libmime/archives.h
@@ -27,6 +27,7 @@ enum rspamd_archive_type {
 
 enum rspamd_archive_flags {
 	RSPAMD_ARCHIVE_ENCRYPTED = (1u << 0u),
+	RSPAMD_ARCHIVE_CANNOT_READ = (1u << 1u),
 };
 
 enum rspamd_archive_file_flags {
diff --git a/src/lua/lua_task.c b/src/lua/lua_task.c
index 2529b88d6..e58ff17c7 100644
--- a/src/lua/lua_task.c
+++ b/src/lua/lua_task.c
@@ -1171,6 +1171,7 @@ LUA_FUNCTION_DEF (archive, get_type);
 LUA_FUNCTION_DEF (archive, get_files);
 LUA_FUNCTION_DEF (archive, get_files_full);
 LUA_FUNCTION_DEF (archive, is_encrypted);
+LUA_FUNCTION_DEF (archive, is_unreadable);
 LUA_FUNCTION_DEF (archive, get_filename);
 LUA_FUNCTION_DEF (archive, get_size);
 
@@ -1179,6 +1180,7 @@ static const struct luaL_reg archivelib_m[] = {
 	LUA_INTERFACE_DEF (archive, get_files),
 	LUA_INTERFACE_DEF (archive, get_files_full),
 	LUA_INTERFACE_DEF (archive, is_encrypted),
+	LUA_INTERFACE_DEF (archive, is_unreadable),
 	LUA_INTERFACE_DEF (archive, get_filename),
 	LUA_INTERFACE_DEF (archive, get_size),
 	{"__tostring", rspamd_lua_class_tostring},
@@ -5935,6 +5937,22 @@ lua_archive_is_encrypted (lua_State *L)
 	return 1;
 }
 
+static gint
+lua_archive_is_unreadable (lua_State *L)
+{
+	LUA_TRACE_POINT;
+	struct rspamd_archive *arch = lua_check_archive (L);
+
+	if (arch != NULL) {
+		lua_pushboolean (L, (arch->flags & RSPAMD_ARCHIVE_CANNOT_READ) ? true : false);
+	}
+	else {
+		return luaL_error (L, "invalid arguments");
+	}
+
+	return 1;
+}
+
 static gint
 lua_archive_get_size (lua_State *L)
 {
diff --git a/src/plugins/lua/mime_types.lua b/src/plugins/lua/mime_types.lua
index 63641b7d0..ccea74dc3 100644
--- a/src/plugins/lua/mime_types.lua
+++ b/src/plugins/lua/mime_types.lua
@@ -1037,13 +1037,20 @@ local function check_mime_type(task)
             if ext and settings.archive_exceptions[ext] then
               check = false
               logger.debugm("mime_types", task, "skip checking of %s as archive, %s is whitelisted",
-                filename, ext)
+                  filename, ext)
             end
           end
           local arch = p:get_archive()
 
           if arch:is_encrypted() then
-            task:insert_result(settings['symbol_encrypted_archive'], 1.0, filename)
+            task:insert_result(settings.symbol_encrypted_archive, 1.0, filename)
+            task:insert_result('MIME_TRACE', 0.0,
+                string.format("%s:%s", p:get_id(), '-'))
+          elseif arch:is_unreadable() then
+            task:insert_result(settings.symbol_encrypted_archive, 0.5, {
+              'compressed header',
+              filename,
+            })
             task:insert_result('MIME_TRACE', 0.0,
                 string.format("%s:%s", p:get_id(), '-'))
           end
-- 
2.39.5