Security Deposits in NYC

[wittlefairy]

I applied for an apartment in Queens, NY recently. The landlord quoted us lease terms of 1 1/2 month security deposit, and 1 month down. My roommate and I are both full-time students, with part-time jobs. Seeing the circumstances, we suggested to the landlord to have a parent co-sign the lease. He seemed to not have a problem with that, ran the credit checks, and then told me that he would need a 3 month security deposit and 1 month down to rent the apartment. Is this legal?