No kidding. I've done financing transactions that had to conform to Sharia law (particularly the usury rules). The amount of hypocrisy that goes into making an interest-bearing loan look like something else is amazing.
In the Middle Ages, such loans were often structured as foreign exchange transactions - in exchange for a certain amount in one currency, the client can pick up an amount in a different currency, subject of course to a certain exchange rate, and a handling fee to be paid from time to time thereafter.
The Venetians were cleverer - they declared usury a terrible sin, upon which the City levied a fine... payable in advance on the first of every year, for your convenience.