104 lines
4.3 KiB
Python
104 lines
4.3 KiB
Python
"""Create GPG ECDSA signatures and public keys using TREZOR device."""
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import io
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import logging
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from . import decode, keyring, protocol
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from .. import util
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log = logging.getLogger(__name__)
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def create_primary(user_id, pubkey, signer_func, secret_bytes=b''):
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"""Export new primary GPG public key, ready for "gpg2 --import"."""
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pubkey_packet = protocol.packet(tag=(5 if secret_bytes else 6),
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blob=(pubkey.data() + secret_bytes))
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user_id_bytes = user_id.encode('utf-8')
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user_id_packet = protocol.packet(tag=13, blob=user_id_bytes)
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data_to_sign = (pubkey.data_to_hash() + user_id_packet[:1] +
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util.prefix_len('>L', user_id_bytes))
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hashed_subpackets = [
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protocol.subpacket_time(pubkey.created), # signature time
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# https://tools.ietf.org/html/rfc4880#section-5.2.3.7
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protocol.subpacket_byte(0x0B, 9), # preferred symmetric algo (AES-256)
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# https://tools.ietf.org/html/rfc4880#section-5.2.3.4
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protocol.subpacket_byte(0x1B, 1 | 2), # key flags (certify & sign)
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# https://tools.ietf.org/html/rfc4880#section-5.2.3.21
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protocol.subpacket_bytes(0x15, [8, 9, 10]), # preferred hash
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# https://tools.ietf.org/html/rfc4880#section-5.2.3.8
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protocol.subpacket_bytes(0x16, [2, 3, 1]), # preferred compression
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# https://tools.ietf.org/html/rfc4880#section-5.2.3.9
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protocol.subpacket_byte(0x17, 0x80), # key server prefs (no-modify)
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# https://tools.ietf.org/html/rfc4880#section-5.2.3.17
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protocol.subpacket_byte(0x1E, 0x01), # advanced features (MDC)
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# https://tools.ietf.org/html/rfc4880#section-5.2.3.24
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]
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unhashed_subpackets = [
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protocol.subpacket(16, pubkey.key_id()), # issuer key id
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protocol.CUSTOM_SUBPACKET]
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signature = protocol.make_signature(
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signer_func=signer_func,
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public_algo=pubkey.algo_id,
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data_to_sign=data_to_sign,
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sig_type=0x13, # user id & public key
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hashed_subpackets=hashed_subpackets,
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unhashed_subpackets=unhashed_subpackets)
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sign_packet = protocol.packet(tag=2, blob=signature)
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return pubkey_packet + user_id_packet + sign_packet
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def create_subkey(primary_bytes, subkey, signer_func, secret_bytes=b''):
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"""Export new subkey to GPG primary key."""
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subkey_packet = protocol.packet(tag=(7 if secret_bytes else 14),
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blob=(subkey.data() + secret_bytes))
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packets = list(decode.parse_packets(io.BytesIO(primary_bytes)))
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primary, user_id, signature = packets[:3]
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data_to_sign = primary['_to_hash'] + subkey.data_to_hash()
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if subkey.ecdh:
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embedded_sig = None
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else:
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# Primary Key Binding Signature
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hashed_subpackets = [
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protocol.subpacket_time(subkey.created)] # signature time
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unhashed_subpackets = [
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protocol.subpacket(16, subkey.key_id())] # issuer key id
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embedded_sig = protocol.make_signature(
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signer_func=signer_func,
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data_to_sign=data_to_sign,
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public_algo=subkey.algo_id,
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sig_type=0x19,
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hashed_subpackets=hashed_subpackets,
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unhashed_subpackets=unhashed_subpackets)
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# Subkey Binding Signature
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# Key flags: https://tools.ietf.org/html/rfc4880#section-5.2.3.21
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# (certify & sign) (encrypt)
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flags = (2) if (not subkey.ecdh) else (4 | 8)
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hashed_subpackets = [
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protocol.subpacket_time(subkey.created), # signature time
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protocol.subpacket_byte(0x1B, flags)]
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unhashed_subpackets = []
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unhashed_subpackets.append(protocol.subpacket(16, primary['key_id']))
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if embedded_sig is not None:
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unhashed_subpackets.append(protocol.subpacket(32, embedded_sig))
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unhashed_subpackets.append(protocol.CUSTOM_SUBPACKET)
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if not decode.has_custom_subpacket(signature):
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signer_func = keyring.create_agent_signer(user_id['value'])
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signature = protocol.make_signature(
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signer_func=signer_func,
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data_to_sign=data_to_sign,
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public_algo=primary['algo'],
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sig_type=0x18,
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hashed_subpackets=hashed_subpackets,
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unhashed_subpackets=unhashed_subpackets)
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sign_packet = protocol.packet(tag=2, blob=signature)
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return primary_bytes + subkey_packet + sign_packet
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