HMAC SHA-512 generation discrepancies between iOS and javascript libraries

Question

I am trying to replicate the Hmac generation behavior from my iOS app using SHA-512 algorithm referring to this link Objective-C sample code for HMAC-SHA1.

For this

Answer 1

HMAC takes a data key and a key and data parameters which are bytes and returns bytes of a length determined by the hash function specified.

Example:

+ (NSData *)doHmacSha512:(NSData *)dataIn
                     key:(NSData *)key
{
    NSMutableData *macOut = [NSMutableData dataWithLength:CC_SHA512_DIGEST_LENGTH];

    CCHmac( kCCHmacAlgSHA512,
            key.bytes,
            key.length,
            dataIn.bytes,
            dataIn.length,
            macOut.mutableBytes);

    return macOut;
}

Test:

NSData *keyData  = [@"MyTestKey" dataUsingEncoding:NSASCIIStringEncoding];
NSData *data     = [@"Now is the time for all good computers to come to the aid of their masters." dataUsingEncoding:NSASCIIStringEncoding];
NSData *hamcData = [Crypto doHmacSha512:data key:keyData]; // Where "Crypto" is the class "doHmacSha512" is defined in.