AES Encryption 128 bit returns null in objective c

AES Encryption 128 bit returns null in objective c

I am trying to encrypt the string using AES128Encryption. Encrypted data
converted to string always returns null.
NSString *iv = @"fedcba9876543210";
NSString *key = @"0123456789abcdef";
- (NSData *)AES128EncryptWithKey
{
char keyPtr[kCCKeySizeAES128 + 1];
bzero( keyPtr, sizeof( keyPtr ) );
[key getCString:keyPtr maxLength:sizeof( keyPtr )
encoding:NSUTF8StringEncoding];
NSUInteger dataLength = [self length];
size_t bufferSize = dataLength + kCCBlockSizeAES128;
void *buffer = malloc( bufferSize );
size_t numBytesEncrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt( kCCEncrypt, kCCAlgorithmAES128,
kCCOptionECBMode | kCCOptionPKCS7Padding,
keyPtr, kCCKeySizeAES128,
NULL ,
[self bytes], dataLength,
buffer, bufferSize,
&numBytesEncrypted );
if( cryptStatus == kCCSuccess )
{
return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
}
}
This is my encryption function.
NSData *data = [@"String to encrypt" dataUsingEncoding:NSUTF8StringEncoding];
NSData *encryptedData = [[NSData alloc] init];
encryptedData = [data AES128EncryptWithKey];
NSLog(@"Encrypted Data Length %d", [encryptedData length]);
if (encryptedData != nil)
{
NSString* myString;
myString = [[NSString alloc] initWithData:encryptedData
encoding:NSUTF8StringEncoding];
NSString* newStr = [NSString stringWithUTF8String:[encryptedData bytes]];
}
After encryption, encryption data length comes as 16 but after converting
it to nsstring it returns null. If I use stringWithUTF16String to convert
it returns like
"軽ﶁែ뼐끨驂퐇". What is
the issue here??