Probably legal, I do not see anything strange that could make such a thing illegal. Most of the answers here are also legal, meaning many think that selling bitcoins with cash is legal. I do not know for sure, but it seems legal.
very clear the reason, bitcoin is a currency, does the currency violate the law? the answer is that the currency does not violate the law, what violates the law is its use, not the currency, so it is clear that bitcoin is legal, even though there are some countries rejecting bitcoin, but they still cannot criminalize bitcoin users, because the state does not have laws digital currency.