# Copyright (c) 2018 Yubico AB
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"""
Connects to the first FIDO device found, creates a new credential for it,
and authenticates the credential. This works with both FIDO 2.0 devices as well
as with U2F devices.
"""
from __future__ import print_function, absolute_import, unicode_literals

from fido2.hid import CtapHidDevice
from fido2.client import Fido2Client
from getpass import getpass
import sys


# Locate a device
dev = next(CtapHidDevice.list_devices(), None)
if not dev:
    print('No FIDO device found')
    sys.exit(1)

# Set up a FIDO 2 client using the origin https://example.com
client = Fido2Client(dev, 'https://example.com')

# Prepare parameters for makeCredential
rp = {'id': 'example.com', 'name': 'Example RP'}
user = {'id': b'user_id', 'name': 'A. User'}
challenge = 'Y2hhbGxlbmdl'

# Create a credential
print('\nTouch your authenticator device now...\n')
try:
    attestation_object, client_data = client.make_credential(
        rp, user, challenge)
except ValueError:
    attestation_object, client_data = client.make_credential(
        rp, user, challenge,
        pin=getpass('Please enter PIN:'))


print('New credential created!')

print('CLIENT DATA:', client_data)
print('ATTESTATION OBJECT:', attestation_object)
print()
print('CREDENTIAL DATA:', attestation_object.auth_data.credential_data)

# Verify signature
attestation_object.verify(client_data.hash)
print('Attestation signature verified!')

credential = attestation_object.auth_data.credential_data

# Prepare parameters for getAssertion
challenge = 'Q0hBTExFTkdF'  # Use a new challenge for each call.
allow_list = [{
    'type': 'public-key',
    'id': credential.credential_id
}]

# Authenticate the credential
print('\nTouch your authenticator device now...\n')

try:
    assertions, client_data = client.get_assertion(
        rp['id'], challenge, allow_list)
except ValueError:
    assertions, client_data = client.get_assertion(
        rp['id'], challenge, allow_list,
        pin=getpass('Please enter PIN:'))

print('Credential authenticated!')

assertion = assertions[0]  # Only one cred in allowList, only one response.

print('CLIENT DATA:', client_data)
print()
print('ASSERTION DATA:', assertion)

# Verify signature
assertion.verify(client_data.hash, credential.public_key)
print('Assertion signature verified!')