dkim.py 文件源码

def sign(self, message):
        canonicalization = NoFWSCanonicalization()
        signer = self._key.signer(padding.PKCS1v15(), hashes.SHA1())

        headers, body = _rfc822_parse(message)

        h_field = []
        for header, value in headers:
            if self._signed_headers is None or header in self._signed_headers:
                h_field.append(header)

                header, value = canonicalization.canonicalize_header(
                    header, value)
                signer.update(header)
                signer.update(b":")
                signer.update(value)
        body = canonicalization.canonicalize_body(body)
        if body:
            signer.update(b"\r\n")
            signer.update(body)

        return _fold(
            b"DomainKey-Signature: a=rsa-sha1; c=nofws; d={domain}; "
            b"s={selector}; q=dns; h={headers}; b={signature}".format(
                domain=self._domain,
                selector=self._selector,
                headers=b": ".join(h_field),
                signature=base64.b64encode(signer.finalize())
            )) + b"\r\n"