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import os
import pytest
from fido2.client import DefaultClientDataCollector, Fido2Client
from fido2.ctap2.extensions import HmacSecretExtension
from fido2.server import Fido2Server
from fido2.utils import websafe_encode
from . import TEST_PIN, CliInteraction
@pytest.fixture(autouse=True, scope="module")
def preconditions(dev_manager):
if "hmac-secret" not in dev_manager.info.extensions:
pytest.skip("hmac-secret not supported by authenticator")
def test_prf(client, pin_protocol):
rp = {"id": "example.com", "name": "Example RP"}
server = Fido2Server(rp)
user = {"id": b"user_id", "name": "A. User"}
uv = "required"
create_options, state = server.register_begin(user, user_verification=uv)
# Create a credential
result = client.make_credential(
{
**create_options["publicKey"],
"extensions": {"prf": {}},
}
)
assert result.client_extension_results.prf.enabled is True
assert result.client_extension_results["prf"]["enabled"] is True
auth_data = server.register_complete(state, result)
credentials = [auth_data.credential_data]
# Complete registration
auth_data = server.register_complete(state, result)
credential = auth_data.credential_data
# Generate a salt for PRF:
salt = websafe_encode(os.urandom(32))
# Prepare parameters for getAssertion
credentials = [credential]
request_options, state = server.authenticate_begin(
credentials, user_verification=uv
)
# Authenticate the credential
result = client.get_assertion(
{
**request_options["publicKey"],
"extensions": {"prf": {"eval": {"first": salt}}},
}
)
# Only one cred in allowCredentials, only one response.
response = result.get_response(0)
output1 = response.client_extension_results.prf.results.first
assert response.client_extension_results["prf"]["results"][
"first"
] == websafe_encode(output1)
# Authenticate again, using two salts to generate two secrets.
# This time we will use evalByCredential, which can be used if there are multiple
# credentials which use different salts. Here it is not needed, but provided for
# completeness of the example.
# Generate a second salt for PRF:
salt2 = websafe_encode(os.urandom(32))
# The first salt is reused, which should result in the same secret.
result = client.get_assertion(
{
**request_options["publicKey"],
"extensions": {
"prf": {
"evalByCredential": {
websafe_encode(credential.credential_id): {
"first": salt,
"second": salt2,
}
}
}
},
}
)
response = result.get_response(0)
output = response.client_extension_results.prf.results
assert output.first == output1
assert output.second != output1
assert response.client_extension_results["prf"]["results"][
"second"
] == websafe_encode(output.second)
def test_hmac_secret(device, pin_protocol, printer):
rp = {"id": "example.com", "name": "Example RP"}
server = Fido2Server(rp)
user = {"id": b"user_id", "name": "A. User"}
uv = "required"
create_options, state = server.register_begin(user, user_verification=uv)
client = Fido2Client(
device,
client_data_collector=DefaultClientDataCollector("https://example.com"),
user_interaction=CliInteraction(printer, TEST_PIN),
extensions=[HmacSecretExtension(allow_hmac_secret=True)],
)
# Create a credential
result = client.make_credential(
{
**create_options["publicKey"],
"extensions": {"hmacCreateSecret": True},
}
)
assert result.client_extension_results.hmac_create_secret is True
assert result.client_extension_results["hmacCreateSecret"] is True
# Complete registration
auth_data = server.register_complete(state, result)
credentials = [auth_data.credential_data]
# Generate a salt for HmacSecret:
salt = os.urandom(32)
# Prepare parameters for getAssertion
request_options, state = server.authenticate_begin(
credentials, user_verification=uv
)
result = client.get_assertion(
{
**request_options["publicKey"],
"extensions": {"hmacGetSecret": {"salt1": salt}},
}
)
result = result.get_response(0)
output1 = result.client_extension_results.hmac_get_secret.output1
assert result.client_extension_results["hmacGetSecret"][
"output1"
] == websafe_encode(output1)
salt2 = os.urandom(32)
result = client.get_assertion(
{
**request_options["publicKey"],
"extensions": {"hmacGetSecret": {"salt1": salt, "salt2": salt2}},
}
)
result = result.get_response(0)
output = result.client_extension_results.hmac_get_secret
assert output.output1 == output1
assert output.output2 != output1
def test_prf_mc(client, pin_protocol, info):
if "hmac-secret-mc" not in info.extensions:
pytest.skip("hmac-secret-mc not supported by authenticator")
rp = {"id": "example.com", "name": "Example RP"}
server = Fido2Server(rp)
user = {"id": b"user_id", "name": "A. User"}
uv = "required"
create_options, state = server.register_begin(user, user_verification=uv)
# Generate salts for PRF:
salt1 = websafe_encode(os.urandom(32))
salt2 = websafe_encode(os.urandom(32))
# Create a credential, with salts
result = client.make_credential(
{
**create_options["publicKey"],
"extensions": {"prf": {"eval": {"first": salt1, "second": salt2}}},
}
)
auth_data = server.register_complete(state, result)
credential = auth_data.credential_data
assert result.client_extension_results.prf.enabled is True
assert result.client_extension_results["prf"]["enabled"] is True
output = result.client_extension_results.prf.results
assert output.first
assert output.second
# Prepare parameters for getAssertion
credentials = [credential]
request_options, state = server.authenticate_begin(
credentials, user_verification=uv
)
# Authenticate the credential
result = client.get_assertion(
{
**request_options["publicKey"],
"extensions": {
"prf": {
"evalByCredential": {
websafe_encode(credential.credential_id): {
"first": salt1,
"second": salt2,
}
}
}
},
}
)
response = result.get_response(0)
assert output == response.client_extension_results.prf.results
|
