Objective-C code for encrypt and decrypt by AES-128 encryption.
/**
http://mythosil.hatenablog.com/entry/20111017/1318873155
http://blog.dealforest.net/2012/03/ios-android-per-aes-crypt-connection/
*/
@interface NSData (AES)
- (NSData *)AES128EncryptedDataWithKey:(NSString *)key;
- (NSData *)AES128DecryptedDataWithKey:(NSString *)key;
- (NSData *)AES128EncryptedDataWithKey:(NSString *)key iv:(NSString *)iv;
- (NSData *)AES128DecryptedDataWithKey:(NSString *)key iv:(NSString *)iv;
@end
#import "NSData+AES.h"
#import <CommonCrypto/CommonCryptor.h>
@implementation NSData (AES)
- (NSData *)AES128EncryptedDataWithKey:(NSString *)key
{
return [self AES128EncryptedDataWithKey:key iv:nil];
}
- (NSData *)AES128DecryptedDataWithKey:(NSString *)key
{
return [self AES128DecryptedDataWithKey:key iv:nil];
}
- (NSData *)AES128EncryptedDataWithKey:(NSString *)key iv:(NSString *)iv
{
return [self AES128Operation:kCCEncrypt key:key iv:iv];
}
- (NSData *)AES128DecryptedDataWithKey:(NSString *)key iv:(NSString *)iv
{
return [self AES128Operation:kCCDecrypt key:key iv:iv];
}
- (NSData *)AES128Operation:(CCOperation)operation key:(NSString *)key iv:(NSString *)iv
{
char keyPtr[kCCKeySizeAES128 + 1];
bzero(keyPtr, sizeof(keyPtr));
[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
char ivPtr[kCCBlockSizeAES128 + 1];
bzero(ivPtr, sizeof(ivPtr));
if (iv) {
[iv getCString:ivPtr maxLength:sizeof(ivPtr) encoding:NSUTF8StringEncoding];
}
NSUInteger dataLength = [self length];
size_t bufferSize = dataLength + kCCBlockSizeAES128;
void *buffer = malloc(bufferSize);
size_t numBytesEncrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(operation,
kCCAlgorithmAES128,
kCCOptionPKCS7Padding | kCCOptionECBMode,
keyPtr,
kCCBlockSizeAES128,
ivPtr,
[self bytes],
dataLength,
buffer,
bufferSize,
&numBytesEncrypted);
if (cryptStatus == kCCSuccess) {
return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
}
free(buffer);
return nil;
}
@end