easy generation of CRC32b hashes

.gitignore

@@ -0,0 +1 @@
+.vscode

Hell'sHall/Hell'sHall/gen_crc32b_hashes.py

@@ -0,0 +1,55 @@
+#!/usr/bin/env python3
+import sys
+
+POLYNOMIAL = 0xedb88320
+INIT_MASK = 0xffffffff
+
+
+def crc32_chksum(in_str: str) -> str:
+    crc = INIT_MASK
+
+    for each_byte in in_str.encode():
+        crc ^= each_byte
+
+        for _ in range(8):
+            mask = INIT_MASK if (crc & 1) else 0x0
+            crc = (crc >> 1) ^ (POLYNOMIAL & mask)
+
+    crc ^= INIT_MASK
+
+    return "".join(("0x", hex(crc)[2:].upper()))
+
+
+def main():
+    try:
+        ntdll_funcs = sys.argv[1].split(',')
+        ntdll_func_dict = {
+            ntdll_func: crc32_chksum(ntdll_func.strip())
+            for ntdll_func in ntdll_funcs
+        }
+
+        out = ""
+        for fn_name, fn_crc32_hash in ntdll_func_dict.items():
+            out = "\n".join(
+                (out, f"#define {fn_name}_CRC32b \t{fn_crc32_hash}"))
+
+        print(out)
+    except Exception:
+        err_msg = f"""[-] Please provide the "ntdll" functions.
+    Usage: {sys.argv[0]} "func1,func2,func3,..."
+
+    e.g.
+        {sys.argv[0]} "NtCreateThreadEx"
+        {sys.argv[0]} "NtCreateThreadEx,NtCreateSection"
+        {sys.argv[0]} "NtCreateThreadEx,NtAllocateVirtualMemory,NtProtectVirtualMemory"
+        """
+
+        print(err_msg)
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    # unit test
+    # assert (crc32_chksum("NtCreateThreadEx") == "0x2073465A")
+
+    main()