miniproto.auth.key_exchange.rsa_pad

miniproto.auth.key_exchange.rsa_pad

rsa_pad(data: bytes, key: RSAKey, *, random_bytes: Callable[[int], bytes] | None = None) -> bytes

Apply Telegram’s randomized RSA_PAD encryption to a small inner payload.

Parameters:

• data (bytes) – Plaintext inner data no longer than 144 bytes.
• key (RSAKey) – Trusted server RSA public key.
• random_bytes (Callable[[int], bytes] | None) – Secure random source for padding and temporary AES key material.

Returns:

• bytes – A 256-byte RSA ciphertext below the server modulus.

Raises:

• ValueError – If the input is oversized or no valid padded integer is produced in 32 attempts.