static ossl_inline unsigned int constant_time_lt(unsigned int a,
                                                 unsigned int b)
{
    return constant_time_msb(a ^ ((a ^ b) | ((a - b) ^ b)));
}
['int RSA_padding_check_SSLv23(unsigned char *to, int tlen,\n                             const unsigned char *from, int flen, int num)\n{\n    int i;\n    unsigned char *em = NULL;\n    unsigned int good, found_zero_byte, mask, threes_in_row;\n    int zero_index = 0, msg_index, mlen = -1, err;\n    if (tlen <= 0 || flen <= 0)\n        return -1;\n    if (flen > num || num < 11) {\n        RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23, RSA_R_DATA_TOO_SMALL);\n        return -1;\n    }\n    em = OPENSSL_malloc(num);\n    if (em == NULL) {\n        RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23, ERR_R_MALLOC_FAILURE);\n        return -1;\n    }\n    for (from += flen, em += num, i = 0; i < num; i++) {\n        mask = ~constant_time_is_zero(flen);\n        flen -= 1 & mask;\n        from -= 1 & mask;\n        *--em = *from & mask;\n    }\n    good = constant_time_is_zero(em[0]);\n    good &= constant_time_eq(em[1], 2);\n    err = constant_time_select_int(good, 0, RSA_R_BLOCK_TYPE_IS_NOT_02);\n    mask = ~good;\n    found_zero_byte = 0;\n    threes_in_row = 0;\n    for (i = 2; i < num; i++) {\n        unsigned int equals0 = constant_time_is_zero(em[i]);\n        zero_index = constant_time_select_int(~found_zero_byte & equals0,\n                                              i, zero_index);\n        found_zero_byte |= equals0;\n        threes_in_row += 1 & ~found_zero_byte;\n        threes_in_row &= found_zero_byte | constant_time_eq(em[i], 3);\n    }\n    good &= constant_time_ge(zero_index, 2 + 8);\n    err = constant_time_select_int(mask | good, err,\n                                   RSA_R_NULL_BEFORE_BLOCK_MISSING);\n    mask = ~good;\n    good &= constant_time_ge(threes_in_row, 8);\n    err = constant_time_select_int(mask | good, err,\n                                   RSA_R_SSLV3_ROLLBACK_ATTACK);\n    mask = ~good;\n    msg_index = zero_index + 1;\n    mlen = num - msg_index;\n    good &= constant_time_ge(tlen, mlen);\n    err = constant_time_select_int(mask | good, err, RSA_R_DATA_TOO_LARGE);\n    tlen = constant_time_select_int(constant_time_lt(num - 11, tlen),\n                                    num - 11, tlen);\n    msg_index = constant_time_select_int(good, msg_index, num - tlen);\n    mlen = num - msg_index;\n    for (mask = good, i = 0; i < tlen; i++) {\n        unsigned int equals = constant_time_eq(msg_index, num);\n        msg_index -= tlen & equals;\n        mask &= ~equals;\n        to[i] = constant_time_select_8(mask, em[msg_index++], to[i]);\n    }\n    OPENSSL_clear_free(em, num);\n    RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23, err);\n    err_clear_last_constant_time(1 & good);\n    return constant_time_select_int(good, mlen, -1);\n}', 'static ossl_inline unsigned int constant_time_ge(unsigned int a,\n                                                 unsigned int b)\n{\n    return ~constant_time_lt(a, b);\n}', 'static ossl_inline unsigned int constant_time_lt(unsigned int a,\n                                                 unsigned int b)\n{\n    return constant_time_msb(a ^ ((a ^ b) | ((a - b) ^ b)));\n}']