diff --git a/test/ectest.c b/test/ectest.c index 0f4259796e..d2ad3774b5 100644 --- a/test/ectest.c +++ b/test/ectest.c @@ -1440,6 +1440,74 @@ err: BN_CTX_free(ctx); return r; } + +/* + * Tests a point known to cause an incorrect underflow in an old version of + * ecp_nist521.c + */ +static int underflow_test(void) +{ + BN_CTX *ctx = NULL; + EC_GROUP *grp = NULL; + EC_POINT *P = NULL, *Q = NULL, *R = NULL; + BIGNUM *x1 = NULL, *y1 = NULL, *z1 = NULL, *x2 = NULL, *y2 = NULL; + BIGNUM *k = NULL; + int testresult = 0; + const char *x1str = + "1534f0077fffffe87e9adcfe000000000000000000003e05a21d2400002e031b1f4" + "b80000c6fafa4f3c1288798d624a247b5e2ffffffffffffffefe099241900004"; + const char *p521m1 = + "1ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" + "fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe"; + + ctx = BN_CTX_new(); + if (!TEST_ptr(ctx)) + return 0; + + BN_CTX_start(ctx); + x1 = BN_CTX_get(ctx); + y1 = BN_CTX_get(ctx); + z1 = BN_CTX_get(ctx); + x2 = BN_CTX_get(ctx); + y2 = BN_CTX_get(ctx); + k = BN_CTX_get(ctx); + if (!TEST_ptr(k)) + goto err; + + grp = EC_GROUP_new_by_curve_name(NID_secp521r1); + P = EC_POINT_new(grp); + Q = EC_POINT_new(grp); + R = EC_POINT_new(grp); + if (!TEST_ptr(grp) || !TEST_ptr(P) || !TEST_ptr(Q) || !TEST_ptr(R)) + goto err; + + if (!TEST_int_gt(BN_hex2bn(&x1, x1str), 0) + || !TEST_int_gt(BN_hex2bn(&y1, p521m1), 0) + || !TEST_int_gt(BN_hex2bn(&z1, p521m1), 0) + || !TEST_int_gt(BN_hex2bn(&k, "02"), 0) + || !TEST_true(EC_POINT_set_Jprojective_coordinates_GFp(grp, P, x1, + y1, z1, ctx)) + || !TEST_true(EC_POINT_mul(grp, Q, NULL, P, k, ctx)) + || !TEST_true(EC_POINT_get_affine_coordinates(grp, Q, x1, y1, ctx)) + || !TEST_true(EC_POINT_dbl(grp, R, P, ctx)) + || !TEST_true(EC_POINT_get_affine_coordinates(grp, R, x2, y2, ctx))) + goto err; + + if (!TEST_int_eq(BN_cmp(x1, x2), 0) + || !TEST_int_eq(BN_cmp(y1, y2), 0)) + goto err; + + testresult = 1; + + err: + BN_CTX_end(ctx); + EC_POINT_free(P); + EC_POINT_free(Q); + EC_GROUP_free(grp); + BN_CTX_free(ctx); + + return testresult; +} # endif static const unsigned char p521_named[] = { @@ -1547,6 +1615,7 @@ int setup_tests(void) # endif # ifndef OPENSSL_NO_EC_NISTP_64_GCC_128 ADD_ALL_TESTS(nistp_single_test, OSSL_NELEM(nistp_tests_params)); + ADD_TEST(underflow_test); # endif ADD_ALL_TESTS(internal_curve_test, crv_len); ADD_ALL_TESTS(internal_curve_test_method, crv_len);