| # Copyright 2017 Google LLC | |
| # | |
| # Licensed under the Apache License, Version 2.0 (the "License"); | |
| # you may not use this file except in compliance with the License. | |
| # You may obtain a copy of the License at | |
| # | |
| # http://www.apache.org/licenses/LICENSE-2.0 | |
| # | |
| # Unless required by applicable law or agreed to in writing, software | |
| # distributed under the License is distributed on an "AS IS" BASIS, | |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
| # See the License for the specific language governing permissions and | |
| # limitations under the License. | |
| """RSA cryptography signer and verifier.""" | |
| try: | |
| # Prefer cryptograph-based RSA implementation. | |
| from google.auth.crypt import _cryptography_rsa | |
| RSASigner = _cryptography_rsa.RSASigner | |
| RSAVerifier = _cryptography_rsa.RSAVerifier | |
| except ImportError: # pragma: NO COVER | |
| # Fallback to pure-python RSA implementation if cryptography is | |
| # unavailable. | |
| from google.auth.crypt import _python_rsa | |
| RSASigner = _python_rsa.RSASigner # type: ignore | |
| RSAVerifier = _python_rsa.RSAVerifier # type: ignore | |