def test_anybody_can_verify():
"""
In the last example, we used the lower-level Crypto API to verify the signature.
Here, we show that anybody can do it without needing to directly access Crypto.
"""
# Alice can sign by default, by dint of her _default_crypto_powerups.
alice = Alice(federated_only=True, start_learning_now=False)
# So, our story is fairly simple: an everyman meets Alice.
somebody = Character(start_learning_now=False, federated_only=True)
# Alice signs a message.
message = b"A message for all my friends who can only verify and not sign."
signature = alice.stamp(message)
# Our everyman can verify it.
somebody.verify_from(alice, message, signature)
# Of course, verification fails with any fake message
with pytest.raises(InvalidSignature):
fake = b"McLovin 892 Momona St. Honolulu, HI 96820"
somebody.verify_from(alice, fake, signature)
# Signature verification also works when Alice is not living with our
# everyman in the same process, and he only knows her by her public key
alice_pubkey_bytes = bytes(alice.stamp)
hearsay_alice = Character.from_public_keys({SigningPower: alice_pubkey_bytes})
somebody.verify_from(hearsay_alice, message, signature)
hearsay_alice = Character.from_public_keys(verifying_key=alice_pubkey_bytes)
somebody.verify_from(hearsay_alice, message, signature)
alice.disenchant()
def test_anybody_can_verify():
"""
In the last example, we used the lower-level Crypto API to verify the signature.
Here, we show that anybody can do it without needing to directly access Crypto.
"""
# Alice can sign by default, by dint of her _default_crypto_powerups.
alice = Alice(federated_only=True, start_learning_now=False)
# So, our story is fairly simple: an everyman meets Alice.
somebody = Character(start_learning_now=False, federated_only=True)
# Alice signs a message.
message = b"A message for all my friends who can only verify and not sign."
signature = alice.stamp(message)
# Our everyman can verify it.
cleartext = somebody.verify_from(alice, message, signature, decrypt=False)
assert cleartext is constants.NO_DECRYPTION_PERFORMED
