Hermes-agent

gateway/platforms/qqbot/crypto.py

@@ -0,0 +1,45 @@
+"""AES-256-GCM utilities for QQBot scan-to-configure credential decryption."""
+
+from __future__ import annotations
+
+import base64
+import os
+
+
+def generate_bind_key() -> str:
+    """Generate a 256-bit random AES key and return it as base64.
+
+    The key is passed to ``create_bind_task`` so the server can encrypt
+    the bot's *client_secret* before returning it.  Only this CLI holds
+    the key, ensuring the secret never travels in plaintext.
+    """
+    return base64.b64encode(os.urandom(32)).decode()
+
+
+def decrypt_secret(encrypted_base64: str, key_base64: str) -> str:
+    """Decrypt a base64-encoded AES-256-GCM ciphertext.
+
+    Ciphertext layout (after base64-decoding)::
+
+        IV (12 bytes) ‖ ciphertext (N bytes) ‖ AuthTag (16 bytes)
+
+    Args:
+        encrypted_base64: The ``bot_encrypt_secret`` value from
+            ``poll_bind_result``.
+        key_base64: The base64 AES key generated by
+            :func:`generate_bind_key`.
+
+    Returns:
+        The decrypted *client_secret* as a UTF-8 string.
+    """
+    from cryptography.hazmat.primitives.ciphers.aead import AESGCM
+
+    key = base64.b64decode(key_base64)
+    raw = base64.b64decode(encrypted_base64)
+
+    iv = raw[:12]
+    ciphertext_with_tag = raw[12:]  # AESGCM expects ciphertext + tag concatenated
+
+    aesgcm = AESGCM(key)
+    plaintext = aesgcm.decrypt(iv, ciphertext_with_tag, None)
+    return plaintext.decode("utf-8")