Objective-C AES128 Encrypt And Decrypt

/**
Base64.h
**/

#import <Foundation/Foundation.h>


@interface NSData (Base64)

+ (NSData *)dataWithBase64EncodedString:(NSString *)string;
- (NSString *)base64EncodedStringWithWrapWidth:(NSUInteger)wrapWidth;
- (NSString *)base64EncodedString;

@end


@interface NSString (Base64)

+ (NSString *)stringWithBase64EncodedString:(NSString *)string;
- (NSString *)base64EncodedStringWithWrapWidth:(NSUInteger)wrapWidth;
- (NSString *)base64EncodedString;
- (NSString *)base64DecodedString;
- (NSData *)base64DecodedData;

@end

/**
Base64.m
**/

#import "Base64.h"


#pragma GCC diagnostic ignored "-Wselector"


#import <Availability.h>
#if !__has_feature(objc_arc)
#error This library requires automatic reference counting
#endif


@implementation NSData (Base64)

+ (NSData *)dataWithBase64EncodedString:(NSString *)string
{
    if (![string length]) return nil;
    
    NSData *decoded = nil;
    
#if __MAC_OS_X_VERSION_MIN_REQUIRED < __MAC_10_9 || __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_7_0
    
    if (![NSData instancesRespondToSelector:@selector(initWithBase64EncodedString:options:)])
    {
        decoded = [[self alloc] initWithBase64Encoding:[string stringByReplacingOccurrencesOfString:@"[^A-Za-z0-9+/=]" withString:@"" options:NSRegularExpressionSearch range:NSMakeRange(0, [string length])]];
    }
    else
        
#endif
        
    {
        decoded = [[self alloc] initWithBase64EncodedString:string options:NSDataBase64DecodingIgnoreUnknownCharacters];
    }
    
    return [decoded length]? decoded: nil;
}

- (NSString *)base64EncodedStringWithWrapWidth:(NSUInteger)wrapWidth
{
    if (![self length]) return nil;
    
    NSString *encoded = nil;
    
#if __MAC_OS_X_VERSION_MIN_REQUIRED < __MAC_10_9 || __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_7_0
    
    if (![NSData instancesRespondToSelector:@selector(base64EncodedStringWithOptions:)])
    {
        //encoded = [self base64Encoding];
        encoded = [self base64EncodedString];
    }
    else
        
#endif
        
    {
        switch (wrapWidth)
        {
            case 64:
            {
                return [self base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
            }
            case 76:
            {
                return [self base64EncodedStringWithOptions:NSDataBase64Encoding76CharacterLineLength];
            }
            default:
            {
                encoded = [self base64EncodedStringWithOptions:(NSDataBase64EncodingOptions)0];
            }
        }
    }
    
    if (!wrapWidth || wrapWidth >= [encoded length])
    {
        return encoded;
    }
    
    wrapWidth = (wrapWidth / 4) * 4;
    NSMutableString *result = [NSMutableString string];
    for (NSUInteger i = 0; i < [encoded length]; i+= wrapWidth)
    {
        if (i + wrapWidth >= [encoded length])
        {
            [result appendString:[encoded substringFromIndex:i]];
            break;
        }
        [result appendString:[encoded substringWithRange:NSMakeRange(i, wrapWidth)]];
        [result appendString:@"\r\n"];
    }
    
    return result;
}

- (NSString *)base64EncodedString
{
    return [self base64EncodedStringWithWrapWidth:0];
}

@end


@implementation NSString (Base64)

+ (NSString *)stringWithBase64EncodedString:(NSString *)string
{
    NSData *data = [NSData dataWithBase64EncodedString:string];
    if (data)
    {
        return [[self alloc] initWithData:data encoding:NSUTF8StringEncoding];
    }
    return nil;
}

- (NSString *)base64EncodedStringWithWrapWidth:(NSUInteger)wrapWidth
{
    NSData *data = [self dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];
    return [data base64EncodedStringWithWrapWidth:wrapWidth];
}

- (NSString *)base64EncodedString
{
    NSData *data = [self dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];
    return [data base64EncodedString];
}

- (NSString *)base64DecodedString
{
    return [NSString stringWithBase64EncodedString:self];
}

- (NSData *)base64DecodedData
{
    return [NSData dataWithBase64EncodedString:self];
}

@end

/**
AES128.h
**/

#import <Foundation/Foundation.h>

@interface AES128 : NSObject
+(NSString *)AES128Encrypt:(NSString *)plainText withKey:(NSString *)key;
+(NSString *)processDecodedString:(NSString *)decoded;
+(NSString *)AES128Decrypt:(NSString *)encryptText withKey:(NSString *)key;

@end

/**
AES128.h
**/

#import "AES128.h"
#import <CommonCrypto/CommonCryptor.h>
#import "Base64.h"

@implementation AES128

+(NSString *)AES128Encrypt:(NSString *)plainText withKey:(NSString *)key
{
    
    if( ![self validKey:key] ){
        return nil;
    }
    
    char keyPtr[kCCKeySizeAES128+1];
    memset(keyPtr, 0, sizeof(keyPtr));
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
    
    
    char ivPtr[kCCBlockSizeAES128+1];
    memset(ivPtr, 0, sizeof(ivPtr));
    [key getCString:ivPtr maxLength:sizeof(ivPtr) encoding:NSUTF8StringEncoding];
    
    NSData* data = [plainText dataUsingEncoding:NSUTF8StringEncoding];
    NSUInteger dataLength = [data length];
    
    int diff = kCCKeySizeAES128 - (dataLength % kCCKeySizeAES128);
    unsigned long newSize = 0;
    
    if(diff > 0)
    {
        newSize = dataLength + diff;
    }
    
    char dataPtr[newSize];
    memcpy(dataPtr, [data bytes], [data length]);
    for(int i = 0; i < diff; i++)
    {
        dataPtr[i + dataLength] =0x0000;
    }
    
    size_t bufferSize = newSize + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);
    memset(buffer, 0, bufferSize);
    
    size_t numBytesCrypted = 0;
    
    CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt,
                                          kCCAlgorithmAES128,
                                          0x0000,
                                          [key UTF8String],
                                          kCCKeySizeAES128,
                                          [key UTF8String],
                                          dataPtr,
                                          sizeof(dataPtr),
                                          buffer,
                                          bufferSize,
                                          &numBytesCrypted);
    
    if (cryptStatus == kCCSuccess) {
        NSData *resultData = [NSData dataWithBytesNoCopy:buffer length:numBytesCrypted];
        return [resultData base64EncodedString];
    }
    free(buffer);
    return nil;
}

+(NSString *)processDecodedString:(NSString *)decoded
{
    if( decoded==nil || decoded.length==0 ){
        return nil;
    }
    const char *tmpStr=[decoded UTF8String];
    int i=0;
    
    while( tmpStr[i]!='\0' )
    {
        i++;
    }
    NSString *final=[[NSString alloc]initWithBytes:tmpStr length:i encoding:NSUTF8StringEncoding];
    return final;
    
}

+(NSString *)AES128Decrypt:(NSString *)encryptText withKey:(NSString *)key
{
    
    if( ![self validKey:key] ){
        return nil;
    }
    
    char keyPtr[kCCKeySizeAES128 + 1];
    memset(keyPtr, 0, sizeof(keyPtr));
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
    
    char ivPtr[kCCBlockSizeAES128 + 1];
    memset(ivPtr, 0, sizeof(ivPtr));
    [key getCString:ivPtr maxLength:sizeof(ivPtr) encoding:NSUTF8StringEncoding];
    
    NSData *data = [encryptText base64DecodedData];
    NSUInteger dataLength = [data length];
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);
    
    size_t numBytesCrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt,
                                          kCCAlgorithmAES128,
                                          0x0000,
                                          [key UTF8String],
                                          kCCBlockSizeAES128,
                                          [key UTF8String],
                                          [data bytes],
                                          dataLength,
                                          buffer,
                                          bufferSize,
                                          &numBytesCrypted);
    if (cryptStatus == kCCSuccess) {
        NSData *resultData = [NSData dataWithBytesNoCopy:buffer length:numBytesCrypted];
        
        NSString *decoded=[[NSString alloc] initWithData:resultData encoding:NSUTF8StringEncoding];
        return [self processDecodedString:decoded];
    }
    
    free(buffer);
    return nil;
    
}

+(BOOL)validKey:(NSString*)key
{
    if( key==nil || key.length !=16 ){
        return NO;
    }
    return YES;
}

-(NSString *)processDecodedString:(NSString *)decoded
{
    if( decoded==nil || decoded.length==0 ){
        return nil;
    }
    const char *tmpStr=[decoded UTF8String];
    int i=0;
    
    while( tmpStr[i]!='\0' )
    {
        i++;
    }
    NSString *final=[[NSString alloc]initWithBytes:tmpStr length:i encoding:NSUTF8StringEncoding];
    return final;
    
}