distribution.py 文件源码

def _sign_string(message, private_key_file=None, private_key_string=None):
        """
        Signs a string for use with Amazon CloudFront.
        Requires the rsa library be installed.
        """
        try:
            import rsa
        except ImportError:
            raise NotImplementedError("Boto depends on the python rsa "
                                      "library to generate signed URLs for "
                                      "CloudFront")
        # Make sure only one of private_key_file and private_key_string is set
        if private_key_file and private_key_string:
            raise ValueError("Only specify the private_key_file or the private_key_string not both")
        if not private_key_file and not private_key_string:
            raise ValueError("You must specify one of private_key_file or private_key_string")
        # If private_key_file is a file name, open it and read it
        if private_key_string is None:
            if isinstance(private_key_file, six.string_types):
                with open(private_key_file, 'r') as file_handle:
                    private_key_string = file_handle.read()
            # Otherwise, treat it like a file
            else:
                private_key_string = private_key_file.read()

        # Sign it!
        private_key = rsa.PrivateKey.load_pkcs1(private_key_string)
        signature = rsa.sign(str(message), private_key, 'SHA-1')
        return signature