Syntax
         
         
            + 
            (
            NSInteger
            ) 
            
               retrieveUserCertificate
            
            : 
            (
            SecKeyRef
            ) 
            privateKey 
            
               andPublicKey
            
            : 
            (
            SecKeyRef
            ) 
            publicKey 
            
               andUserName
            
            : 
            (
            NSString *
            ) 
            userName 
            
               andPassword
            
            : 
            (
            NSString *
            ) 
            password 
            
               andChallenge
            
            : 
            (
            NSString *
            ) 
            challengeCode 
            
               outCertificate
            
            : 
            (
            SecCertificateRef *
            ) 
            userCertificate