Easy Data Encryption

header

#import <Foundation/Foundation.h>

@interface MomentEncrypter : NSValueTransformer

@property NSData *key;
@property NSData *iv;

- (void)setKeyAndIVWith:(NSString*)password;

@end

implementation

#import "MomentEncrypter.h"
#import <CocoaSecurity/CocoaSecurity.h>

@implementation MomentEncrypter

+ (BOOL)allowsReverseTransformation
{
    return YES;
}

+ (Class)transformedValueClass
{
    return NSData.class;
}

- (id)init
{
    self = [super init];
    if (self) {
        [self setKeyAndIVWith:@"password"];
    }
    return self;
}

- (id)transformedValue:(id)dataIn
{
    //encrypt string
    CocoaSecurityResult *encrypted = [CocoaSecurity aesEncryptWithData:dataIn key:self.key iv:self.iv];
    NSData *enctypedData = encrypted.data;
    
    return enctypedData;
}

- (id)reverseTransformedValue:(id)dataIn
{
    CocoaSecurityResult *decryptedResult = [CocoaSecurity aesDecryptWithData:dataIn key:self.key iv:self.iv];
    NSData *decryptedData = decryptedResult.data;
    
    return decryptedData;
}

- (void)setKeyAndIVWith:(NSString *)password
{
    CocoaSecurityResult *keyIV = [CocoaSecurity sha384:password];
    self.key = [keyIV.data subdataWithRange:NSMakeRange(0, 32)];
    self.iv = [keyIV.data subdataWithRange:NSMakeRange(32, 16)];
}

@end