def verify(jwsjs): """Return (decoded headers, payload) if all signatures in jwsjs are consistent, else raise ValueError. Caller must decide whether the keys are actually trusted.""" get_ed25519ll() # XXX forbid duplicate keys in JSON input using object_pairs_hook (2.7+) recipients = jwsjs["recipients"] encoded_payload = binary(jwsjs["payload"]) headers = [] for recipient in recipients: assertTrue( len(recipient) == 2, "Unknown recipient key {0}".format(recipient)) h = binary(recipient["header"]) s = binary(recipient["signature"]) header = json.loads(native(urlsafe_b64decode(h))) assertTrue(header["alg"] == ALG, "Unexpected algorithm {0}".format(header["alg"])) if "alg" in header["jwk"] and "kty" not in header["jwk"]: header["jwk"]["kty"] = header["jwk"]["alg"] # b/w for JWK < -08 assertTrue( header["jwk"]["kty"] == ALG, # true for Ed25519 "Unexpected key type {0}".format(header["jwk"]["kty"]), ) vk = urlsafe_b64decode(binary(header["jwk"]["vk"])) secured_input = b".".join((h, encoded_payload)) sig = urlsafe_b64decode(s) sig_msg = sig + secured_input verified_input = native(ed25519ll.crypto_sign_open(sig_msg, vk)) verified_header, verified_payload = verified_input.split(".") verified_header = binary(verified_header) decoded_header = native(urlsafe_b64decode(verified_header)) headers.append(json.loads(decoded_header)) verified_payload = binary(verified_payload) # only return header, payload that have passed through the crypto library. payload = json.loads(native(urlsafe_b64decode(verified_payload))) return headers, payload
def verify(jwsjs): """Return (decoded headers, payload) if all signatures in jwsjs are consistent, else raise ValueError. Caller must decide whether the keys are actually trusted.""" get_ed25519ll() # XXX forbid duplicate keys in JSON input using object_pairs_hook (2.7+) recipients = jwsjs["recipients"] encoded_payload = binary(jwsjs["payload"]) headers = [] for recipient in recipients: assertTrue(len(recipient) == 2, "Unknown recipient key {0}".format(recipient)) h = binary(recipient["header"]) s = binary(recipient["signature"]) header = json.loads(native(urlsafe_b64decode(h))) assertTrue(header["alg"] == ALG, "Unexpected algorithm {0}".format(header["alg"])) if "alg" in header["jwk"] and "kty" not in header["jwk"]: header["jwk"]["kty"] = header["jwk"]["alg"] # b/w for JWK < -08 assertTrue(header["jwk"]["kty"] == ALG, # true for Ed25519 "Unexpected key type {0}".format(header["jwk"]["kty"])) vk = urlsafe_b64decode(binary(header["jwk"]["vk"])) secured_input = b".".join((h, encoded_payload)) sig = urlsafe_b64decode(s) sig_msg = sig+secured_input verified_input = native(ed25519ll.crypto_sign_open(sig_msg, vk)) verified_header, verified_payload = verified_input.split('.') verified_header = binary(verified_header) decoded_header = native(urlsafe_b64decode(verified_header)) headers.append(json.loads(decoded_header)) verified_payload = binary(verified_payload) # only return header, payload that have passed through the crypto library. payload = json.loads(native(urlsafe_b64decode(verified_payload))) return headers, payload