Appendix B. Previous IETF FNV Code

Questa sezione conserva il testo RFC su FNV, includendo FNV primes, offset_basis, endianism, XOR folding, constants, non-cryptographic security guidance, source code, test code, Makefile e confronti con SHA-1 and SHA-256.

Testo RFC originale

Appendix B.  Previous IETF FNV Code

   FNV-1a was referenced in draft-ietf-tls-cached-info-08 (which was
   ultimately published as RFC 7924, but RFC 7924 no longer contains the
   code below).  Herein, we provide the Java code for FNV64 from that
   earlier draft, included with the kind permission of the author:

   <CODE BEGINS>
    /*
    * Java code sample, implementing 64 bit FNV-1a
    * By Stefan Santesson
    */

   import java.math.BigInteger;

   public class FNV {

      static public BigInteger getFNV1a64Digest (String inpString) {

          BigInteger m = new BigInteger("2").pow(64);
          BigInteger fnvPrime = new BigInteger("1099511628211");
          BigInteger fnvOffsetBasis = new BigInteger
                                      ("14695981039346656037");

          BigInteger digest = fnvOffsetBasis;

          for (int i = 0; i < inpString.length(); i++) {
              digest = digest.xor(BigInteger.valueOf(
                       (int) inpString.charAt(i)));
              digest = digest.multiply(fnvPrime).mod(m);
          }
          return (digest);

      }
   }
   <CODE ENDS>