How to appropriately encrypt and decrypt a NSString with AES 128 - ios

Question

I am using http://aes.online-domain-tools.com to encrypt my NSString and what i get back from this is an array of unsigned char like this c2 84 6b 71 72 6d d2 e7 cd 0b a6 08 cd 85 c3 0c.
Then is use this to convert it into NSString in my code:
const unsigned char encrpytedAppIDbytes[] = {0xe5, 0x35, 0xdf, 0x72, 0x57, 0xaf, 0xf7, 0xe6, 0x1f, 0x6d, 0x51, 0x1d, 0x26, 0xe8, 0x5e, 0xa2};
NSData *appIDToDecrypt = [NSData dataWithBytes:encrpytedAppIDbytes length:sizeof(encrpytedAppIDbytes)];
NSString *decryptedAppID = [[NSString alloc] initWithData:[appIDToDecrypt AES128DecryptedDataWithKey:#"something"] encoding:NSUTF8StringEncoding];
if([decryptedAppID isEqualToString:#"Something"]){} // This fails even when i look at them in the debugger they are the same.
But when i am trying to decrypt it, its showing up as the same string but when i compare it with the same NSString hardcode to check if it is the same string it doesn't work.
This fails some authentication check i have in my app.
Please point anything wrong i am doing here.
Thanks,

Answer 1

Alright so after spending few hours with it i finally found the solutions which might not be optimal but works in my case.
It seems like after decryption, the string contains some other characters which are not visible in the debugger but when i am trying to check the length it shows greater than the number of characters in it which indicates that there is something wrong. For now what i have done is this :
const unsigned char nameBytes[] = {0xa6, 0xf0, 0xea, 0x36, 0x5f, 0x78, 0xb7, 0x52, 0x29, 0x6a, 0x67, 0xb7, 0xeb, 0x73, 0xd5, 0x14};
NSData *nameBytesData = [NSData dataWithBytes:nameBytes length:sizeof(nameBytes)];
NSString *nameBytesString = [[NSString alloc] initWithData:[nameBytesData AES128DecryptedDataWithKey:#"PaymentGateway"] encoding:NSUTF8StringEncoding];
NSCharacterSet * set = [[NSCharacterSet characterSetWithCharactersInString:#"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLKMNOPQRSTUVWXYZ0123456789"] invertedSet];
NSString *safeSearchString = [[nameBytesString componentsSeparatedByCharactersInSet:set] componentsJoinedByString:#""];
NSLog(#"length:%lu",(unsigned long)[safeSearchString length]);
NSLog(#"lengthActual:%lu",(unsigned long)[#"ashutosh" length]);
if ([safeSearchString isEqualToString:#"ashutosh"]) {
NSLog(#"Success");
}
NSLog(#"Decrypted:%#",nameBytesString);
The code above removes all the special characters and replaces it with #"" so the resulted string only has valid chars. For adding support to consider more chars as valid just add them to NSCharacterSet * set.