AES Encryption/Decryption on Objective-C

FWEncryptorAES.h

//
//  FWEncryptorAES.h
//  AES Encryptor
//
//  Created by FrankWu on 2013/12/20.
//  Copyright (c) 2013年 FrankWu. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface FWEncryptorAES : NSObject

+ (NSData *)encrypt:(NSData *)data Key:(id)key IV:(id)iv;
+ (NSData *)decrypt:(NSData *)data Key:(id)key IV:(id)iv;

+ (NSString *)encryptToBase64:(NSData *)data Key:(id)key IV:(id)iv;
+ (NSData *)decryptFromBase64:(NSString *)data Key:(id)key IV:(id)iv;

+ (NSData *)getKey:(NSString *)key;
+ (NSData *)getIV:(NSString *)iv;

+ (NSString*)convertHexStringFromData:(NSData*)data;

@end

FWEncryptorAES.m

//
//  FWEncryptorAES.m
//  AES Encryptor
//
//  Created by FrankWu on 2013/12/20.
//  Copyright (c) 2013年 FrankWu. All rights reserved.
//

#import "FWEncryptorAES.h"
#import "NSData+CommonCrypto.h"
#import "NSData+Base64.h"

@implementation FWEncryptorAES

+ (NSData *)encrypt:(NSData *)data Key:(id)key IV:(id)iv
{
    NSParameterAssert([key isKindOfClass: [NSData class]] || [key isKindOfClass: [NSString class]]);
    NSParameterAssert([iv isKindOfClass: [NSData class]] || [iv isKindOfClass: [NSString class]]);
    
    NSData *keyData = [self getKey:key];
    NSData *ivData = [self getIV:iv];
    
    CCCryptorStatus status = kCCSuccess;
    NSData *encrypted = [data dataEncryptedUsingAlgorithm:kCCAlgorithmAES128 key:keyData initializationVector:ivData options:kCCOptionPKCS7Padding error:&status];
    
    return encrypted;
}

+ (NSData *)decrypt:(NSData *)data Key:(id)key IV:(id)iv
{
    NSParameterAssert([key isKindOfClass: [NSData class]] || [key isKindOfClass: [NSString class]]);
    NSParameterAssert([iv isKindOfClass: [NSData class]] || [iv isKindOfClass: [NSString class]]);
    
    NSData *keyData = [self getKey:key];
    NSData *ivData = [self getIV:iv];
    
    CCCryptorStatus status = kCCSuccess;
    NSData *decrypted = [data decryptedDataUsingAlgorithm:kCCAlgorithmAES128 key:keyData initializationVector:ivData options:kCCOptionPKCS7Padding error:&status];
    
    return decrypted;
}

+ (NSString *)encryptToBase64:(NSData *)data Key:(id)key IV:(id)iv
{
    NSParameterAssert([key isKindOfClass: [NSData class]] || [key isKindOfClass: [NSString class]]);
    NSParameterAssert([iv isKindOfClass: [NSData class]] || [iv isKindOfClass: [NSString class]]);
    
    NSData *encrypted = [self encrypt:data Key:key IV:iv];
    return [encrypted base64EncodedString];\
}

+ (NSData *)decryptFromBase64:(NSString *)str Key:(id)key IV:(id)iv
{
    NSParameterAssert([key isKindOfClass: [NSData class]] || [key isKindOfClass: [NSString class]]);
    NSParameterAssert([iv isKindOfClass: [NSData class]] || [iv isKindOfClass: [NSString class]]);
    
    NSData *data = [NSData dataFromBase64String:str];
    
    NSData *decrypted = [self decrypt:data Key:key IV:iv];
    return decrypted;
}

+ (NSData *)getKey:(id)key
{
    NSParameterAssert([key isKindOfClass: [NSData class]] || [key isKindOfClass: [NSString class]]);
    
    if ([key isKindOfClass: [NSString class]])
        return [[key dataUsingEncoding:NSUTF8StringEncoding] SHA256Hash];
    else
        return (NSData *)key;
}

+ (NSData *)getIV:(id)iv
{
    NSParameterAssert([iv isKindOfClass: [NSData class]] || [iv isKindOfClass: [NSString class]]);
    
    if ([iv isKindOfClass: [NSString class]])
        return [[iv dataUsingEncoding:NSUTF8StringEncoding] MD5Sum];
    else
        return (NSData *)iv;
}

+ (NSString*)convertHexStringFromData:(NSData*)data
{
    const unsigned char *result = [data bytes];
    NSMutableString *str = [NSMutableString stringWithCapacity:[data length]];
    for(int i = 0; i<[data length]; i++)
    {
        [str appendFormat:@"%02x",result[i]];
    }
    return str;
}

@end

Concise, easy to understand. Good!

#import "NSData+CommonCrypto.h" file not found ..

#import "NSData+CommonCrypto.h" file not found ..

You can use #import <CommonCrypto/CommonCrypto.h>

#import "NSData+Base64.h" file not found

Hi all,

Please find all related files here: https://github.com/FrankWu100/FWEncryptorAES/tree/master/Objective-C/Src

Does this code works encrypts/decrypts only strings or also files?

Also support files, via NSData.
https://github.com/FrankWu100/FWEncryptorAES/blob/master/Objective-C/Src/FWEncryptorAES.m#L15-L41

Actually, NSString is based on NSData.
https://github.com/FrankWu100/FWEncryptorAES/blob/master/Objective-C/Src/FWEncryptorAES.m#L67
https://github.com/FrankWu100/FWEncryptorAES/blob/master/Objective-C/Src/FWEncryptorAES.m#L48

Thank you! Great job 👍