Java/j2objc example of iOS CommonCrypto's CCHmac function

HashTest.java

/*-[
#import <CommonCrypto/CommonHMAC.h>
]-*/;

class HashTest {
  private static native String hash(String key, String data) /*-[
    const char *cKey  = [key cStringUsingEncoding:NSASCIIStringEncoding];
    const char *cData = [data cStringUsingEncoding:NSASCIIStringEncoding];

    unsigned char cHMAC[CC_SHA256_DIGEST_LENGTH];

    CCHmac(kCCHmacAlgSHA256, cKey, strlen(cKey), cData, strlen(cData), cHMAC);
    NSData *out = [NSData dataWithBytes:cHMAC length:CC_SHA256_DIGEST_LENGTH];
    return [out base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
  ]-*/;

  public static void main(String... args) throws Exception {
    System.out.println(hash("mykey", "my_message"));
  }
}