CCKeyDerivationPBKDF on iOS5

I'm trying to write a password encryption function into my app, following this article.

I wrote a function that runs the CCCalibratePBKDF function and outputs the number of rounds.

const uint32_t oneSecond = 1000;
uint rounds = CCCalibratePBKDF(kCCPBKDF2,
                               predictedPasswordLength,
                               predictedSaltLength,
                               kCCPRFHmacAlgSHA256,
                               kCCKeySizeAES128,
                               oneSecond);

This works perfectly, but when I try to implement the next part it all goes wrong.

I can start writing the CCKeyDerivationPBKDF function call and it auto-completes the function and all the parameters. As I go through filling it in all the parameters are also auto-completed.

- (NSData *)authenticationDataForPassword: (NSString *)password salt: (NSData *)salt rounds: (uint) rounds
{
    const NSString *plainData = @"Fuzzy Aliens";
    uint8_t key[kCCKeySizeAES128] = {0};
    int keyDerivationResult = CCKeyDerivationPBKDF(kCCPBKDF2,
                                                   [password UTF8String],
                                                   [password lengthOfBytesUsingEncoding: NSUTF8StringEncoding],
                                                   [salt bytes],
                                                   [salt length],
                                                   kCCPRFHmacAlgSHA256,
                                                   rounds,
                                                   key,
                                                   kCCKeySizeAES128);
    if (keyDerivationResult == kCCParamError) {
        //you shouldn't get here with the parameters as above
        return nil;
    }
    uint8_t hmac[CC_SHA256_DIGEST_LENGTH] = {0};
    CCHmac(kCCHmacAlgSHA256,
           key,
           kCCKeySizeAES128,
           [plainData UTF8String],
           [plainData lengthOfBytesUsingEncoding: NSUTF8StringEncoding],
           hmac);
    NSData *hmacData = [NSData dataWithBytes: hmac length: CC_SHA256_DIGEST_LENGTH];
    return hmacData;
}

But as soon as I hit ; it marks an error saying "No matching function for call to 'CCKeyDerivationPBKDF'" and it won't build or anything.

I've imported CommonCrypto/CommonKeyDerivation.h and CommonCrypto/CommonCryptor.h as both of these were necessary for the enum names.