static int GetASNNull(const byte* input, word32* inOutIdx, word32 maxIdx)
{
    word32 idx = *inOutIdx;
    byte   b;

    if ((idx + 2) > maxIdx)
        return BUFFER_E;

    b = input[idx++];
    if (b != ASN_TAG_NULL)
        return ASN_TAG_NULL_E;

    if (input[idx++] != 0)
        return ASN_EXPECT_0_E;

    *inOutIdx = idx;
    return 0;
}
static int GetASNNull(const byte* input, word32* inOutIdx, word32 maxIdx)
{
    word32 idx = *inOutIdx;
    byte   b;

    if ((idx + 2) > maxIdx)
        return BUFFER_E;

    b = input[idx++];
    if (b != ASN_TAG_NULL)
        return ASN_TAG_NULL_E;

    if (input[idx++] != 0)
        return ASN_EXPECT_0_E;

    *inOutIdx = idx;
    return 0;
}