| 424 | return self._sign(k_signing, string_to_sign, hex=True) |
| 425 | |
| 426 | def add_auth(self, request): |
| 427 | if self.credentials is None: |
| 428 | raise NoCredentialsError() |
| 429 | datetime_now = datetime.datetime.utcnow() |
| 430 | request.context['timestamp'] = datetime_now.strftime(SIGV4_TIMESTAMP) |
| 431 | # This could be a retry. Make sure the previous |
| 432 | # authorization header is removed first. |
| 433 | self._modify_request_before_signing(request) |
| 434 | canonical_request = self.canonical_request(request) |
| 435 | logger.debug("Calculating signature using v4 auth.") |
| 436 | logger.debug('CanonicalRequest:\n%s', canonical_request) |
| 437 | string_to_sign = self.string_to_sign(request, canonical_request) |
| 438 | logger.debug('StringToSign:\n%s', string_to_sign) |
| 439 | signature = self.signature(string_to_sign, request) |
| 440 | logger.debug('Signature:\n%s', signature) |
| 441 | |
| 442 | self._inject_signature_to_request(request, signature) |
| 443 | |
| 444 | def _inject_signature_to_request(self, request, signature): |
| 445 | auth_str = [f'AWS4-HMAC-SHA256 Credential={self.scope(request)}'] |