Method sign

src/pyelliptic/ecc.py:305–372

Sign the input with ECDSA method and returns the signature

(self, inputb, digest_alg=OpenSSL.digest_ecdsa_sha1)

                OpenSSL.BN_free(priv_key)

    def sign(self, inputb, digest_alg=OpenSSL.digest_ecdsa_sha1):
        """
        Sign the input with ECDSA method and returns the signature
        """
        try:
            size = len(inputb)
            buff = OpenSSL.malloc(inputb, size)
            digest = OpenSSL.malloc(0, 64)
            if OpenSSL._hexversion > 0x10100000 and not OpenSSL._libreSSL:
                md_ctx = OpenSSL.EVP_MD_CTX_new()
            else:
                md_ctx = OpenSSL.EVP_MD_CTX_create()
            dgst_len = OpenSSL.pointer(OpenSSL.c_int(0))
            siglen = OpenSSL.pointer(OpenSSL.c_int(0))
            sig = OpenSSL.malloc(0, 151)

            key = OpenSSL.EC_KEY_new_by_curve_name(self.curve)
            if key == 0:
                raise Exception("[OpenSSL] EC_KEY_new_by_curve_name FAIL ...")

            priv_key = OpenSSL.BN_bin2bn(self.privkey, len(self.privkey), 0)
            pub_key_x = OpenSSL.BN_bin2bn(self.pubkey_x, len(self.pubkey_x), 0)
            pub_key_y = OpenSSL.BN_bin2bn(self.pubkey_y, len(self.pubkey_y), 0)

            if (OpenSSL.EC_KEY_set_private_key(key, priv_key)) == 0:
                raise Exception("[OpenSSL] EC_KEY_set_private_key FAIL ...")

            group = OpenSSL.EC_KEY_get0_group(key)
            pub_key = OpenSSL.EC_POINT_new(group)

            if (OpenSSL.EC_POINT_set_affine_coordinates_GFp(group, pub_key,
                                                            pub_key_x,
                                                            pub_key_y,
                                                            0)) == 0:
                raise Exception(
                    "[OpenSSL] EC_POINT_set_affine_coordinates_GFp FAIL ...")
            if (OpenSSL.EC_KEY_set_public_key(key, pub_key)) == 0:
                raise Exception("[OpenSSL] EC_KEY_set_public_key FAIL ...")
            if (OpenSSL.EC_KEY_check_key(key)) == 0:
                raise Exception("[OpenSSL] EC_KEY_check_key FAIL ...")

            if OpenSSL._hexversion > 0x10100000 and not OpenSSL._libreSSL:
                OpenSSL.EVP_MD_CTX_new(md_ctx)
            else:
                OpenSSL.EVP_MD_CTX_init(md_ctx)
            OpenSSL.EVP_DigestInit_ex(md_ctx, digest_alg(), None)

            if (OpenSSL.EVP_DigestUpdate(md_ctx, buff, size)) == 0:
                raise Exception("[OpenSSL] EVP_DigestUpdate FAIL ...")
            OpenSSL.EVP_DigestFinal_ex(md_ctx, digest, dgst_len)
            OpenSSL.ECDSA_sign(0, digest, dgst_len.contents, sig, siglen, key)
            if (OpenSSL.ECDSA_verify(0, digest, dgst_len.contents, sig,
                                     siglen.contents, key)) != 1:
                raise Exception("[OpenSSL] ECDSA_verify FAIL ...")

            return sig.raw[:siglen.contents.value]

        finally: