java hmac sha512_HMACSHA512

- (NSString *)generate:(NSString *)secretKey {

NSString *counter = @"1527866554";

NSData *counterBytes = [counter dataUsingEncoding:NSUTF8StringEncoding];

NSData *keyBytes = [secretKey dataUsingEncoding:NSUTF8StringEncoding];

NSMutableData *macOut = [NSMutableData dataWithLength:CC_SHA512_DIGEST_LENGTH];

CCHmac( kCCHmacAlgSHA512,

keyBytes.bytes,

keyBytes.length,

counterBytes.bytes,

counterBytes.length,

macOut.mutableBytes);

unsigned long long hash = 0;

[macOut getBytes:&hash length:sizeof(unsigned long)];

unsigned long long token = hash % (unsigned long)pow(10, 15);

NSString *strToken = [NSString stringWithFormat:@"%015lld", token];

NSLog(@"secret key = %@, counter = %@, payment code = %@", secretKey, counter, strToken);

return strToken;

}