cert.py 文件源码

def _rsassa_pkcs1_v1_5_sign(self, M, h):
        """
        Implements RSASSA-PKCS1-v1_5-SIGN() function as described in
        Sect. 8.2.1 of RFC 3447.

        Input:
           M: message to be signed, an octet string
           h: hash function name (in 'md2', 'md4', 'md5', 'sha1', 'tls'
                'sha256', 'sha384').

        Output:
           the signature, an octet string.
        """

        # 1) EMSA-PKCS1-v1_5 encoding
        k = self.modulusLen / 8
        EM = pkcs_emsa_pkcs1_v1_5_encode(M, k, h)
        if EM is None:
            warning("Key._rsassa_pkcs1_v1_5_sign(): unable to encode")
            return None

        # 2) RSA signature
        m = pkcs_os2ip(EM)                          # 2.a)
        s = self._rsasp1(m)                         # 2.b)
        S = pkcs_i2osp(s, k)                        # 2.c)

        return S                                    # 3)