You are rhetorically clever but analytically wrong on almost every premise.
Your claim rests on UNSC inaction = judicial approval = legal sanction. This is false on multiple levels.
A supreme court saying something is legal relies on an affirmative ruling. A body simply declining to act, especially for political reasons such as a Russian or Chinese veto, is not a ruling of any kind.
The UNSC is also not a court. It is a political body of 15 member states that authorize enforcement actions related to international peace and security. It does not make legal rulings. The actual judicial body in the UN system is the International Court of Justice (ICJ). The ICJ has made no ruling on the strait of Hormuz situation.
You also conflate UNSC inaction with legality. That's an interesting philosophical position, but by that exact logic:
* The apartheid of South Africa was "legal" because the UNSC was blocked from acting decisively on the issue for decades.
* The US/Israel strikes on Iran were "legal" because the UNSC never vetoed it.
* The Israeli genocide of Palestine is "legal" because it was protected by UNSC veto.
Obviously, quite flawed logic.
Overall, three errors:
1) you conflated legal inaction as affirmative legal action.
2) you conflated a political body with a legal one.
3) you conflated UNSC inaction with legality.