gpg: use 'gpg-agent.conf' to configure trezor-gpg-agent

currently support logfile and logging verbosity

scripts/gpg-init

@@ -23,3 +23,8 @@ echo "${FINGERPRINT}:6" | gpg2 --homedir "${HOMEDIR}" --import-ownertrust
 echo "# TREZOR-based GPG configuration
 agent-program $(which trezor-gpg-agent)
 " | tee "${HOMEDIR}/gpg.conf"
+
+echo "# TREZOR-based GPG agent emulator
+log-file ${HOMEDIR}/gpg-agent.log
+verbosity 2
+" | tee "${HOMEDIR}/gpg-agent.conf"

trezor_agent/gpg/__main__.py

@@ -4,6 +4,7 @@ import argparse
 import contextlib
 import io
 import logging
+import os
 import sys
 import time
 
@@ -98,6 +99,14 @@ def main_create():
 
 def main_agent():
     """Run a simple GPG-agent server."""
+    home_dir = os.environ.get('GNUPGHOME', os.path.expanduser('~/.gnupg/trezor'))
+    config_file = os.path.join(home_dir, 'gpg-agent.conf')
+    lines = (line.strip() for line in open(config_file))
+    lines = (line for line in lines if line and not line.startswith('#'))
+    config = dict(line.split(' ', 1) for line in lines)
+
+    util.setup_logging(verbosity=int(config['verbosity']),
+                       filename=config['log-file'])
     sock_path = keyring.get_agent_sock_path()
     with server.unix_domain_socket_server(sock_path) as sock:
         for conn in agent.yield_connections(sock):

trezor_agent/util.py

@@ -229,10 +229,10 @@ def get_bip32_address(identity, ecdh=False):
     return [(hardened | value) for value in address_n]
 
 
-def setup_logging(verbosity):
+def setup_logging(verbosity, **kwargs):
     """Configure logging for this tool."""
     fmt = ('%(asctime)s %(levelname)-12s %(message)-100s '
            '[%(filename)s:%(lineno)d]')
     levels = [logging.WARNING, logging.INFO, logging.DEBUG]
     level = levels[min(verbosity, len(levels) - 1)]
-    logging.basicConfig(format=fmt, level=level)
+    logging.basicConfig(format=fmt, level=level, **kwargs)