backend.py 文件源码

def _evp_pkey_to_private_key(self, evp_pkey):
        """
        Return the appropriate type of PrivateKey given an evp_pkey cdata
        pointer.
        """

        key_type = self._lib.Cryptography_EVP_PKEY_id(evp_pkey)

        if key_type == self._lib.EVP_PKEY_RSA:
            rsa_cdata = self._lib.EVP_PKEY_get1_RSA(evp_pkey)
            self.openssl_assert(rsa_cdata != self._ffi.NULL)
            rsa_cdata = self._ffi.gc(rsa_cdata, self._lib.RSA_free)
            return _RSAPrivateKey(self, rsa_cdata, evp_pkey)
        elif key_type == self._lib.EVP_PKEY_DSA:
            dsa_cdata = self._lib.EVP_PKEY_get1_DSA(evp_pkey)
            self.openssl_assert(dsa_cdata != self._ffi.NULL)
            dsa_cdata = self._ffi.gc(dsa_cdata, self._lib.DSA_free)
            return _DSAPrivateKey(self, dsa_cdata, evp_pkey)
        elif (self._lib.Cryptography_HAS_EC == 1 and
              key_type == self._lib.EVP_PKEY_EC):
            ec_cdata = self._lib.EVP_PKEY_get1_EC_KEY(evp_pkey)
            self.openssl_assert(ec_cdata != self._ffi.NULL)
            ec_cdata = self._ffi.gc(ec_cdata, self._lib.EC_KEY_free)
            return _EllipticCurvePrivateKey(self, ec_cdata, evp_pkey)
        else:
            raise UnsupportedAlgorithm("Unsupported key type.")