crypt.py 文件源码

def from_string(key_pem, is_x509_cert):
      """Construct a Verified instance from a string.

      Args:
        key_pem: string, public key in PEM format.
        is_x509_cert: bool, True if key_pem is an X509 cert, otherwise it is
          expected to be an RSA key in PEM format.

      Returns:
        Verifier instance.
      """
      if is_x509_cert:
        if isinstance(key_pem, six.text_type):
          key_pem = key_pem.encode('ascii')
        pemLines = key_pem.replace(b' ', b'').split()
        certDer = _urlsafe_b64decode(b''.join(pemLines[1:-1]))
        certSeq = DerSequence()
        certSeq.decode(certDer)
        tbsSeq = DerSequence()
        tbsSeq.decode(certSeq[0])
        pubkey = RSA.importKey(tbsSeq[6])
      else:
        pubkey = RSA.importKey(key_pem)
      return PyCryptoVerifier(pubkey)