code: public static HashAlgorithm getHashAlgorithm(String hashAlgorithm) {
  	if (hashAlgorithm==null) {
  		return null;
  	}
  	switch (hashAlgorithm) {
  		case "md2": return HashAlgorithm.md2;
  		case "md4": return HashAlgorithm.md4;
  		case "md5": return HashAlgorithm.md5;
  		case "none": return HashAlgorithm.none;
  		case "ripemd128": return HashAlgorithm.ripemd128;
  		case "ripemd160": return HashAlgorithm.ripemd160;
  		case "sha1": return HashAlgorithm.sha1;
  		case "sha224": return HashAlgorithm.sha224;
  		case "sha256": return HashAlgorithm.sha256;
  		case "sha384": return HashAlgorithm.sha384;
  		case "sha512": return HashAlgorithm.sha512;
  		case "whirlpool": return HashAlgorithm.whirlpool;
  		default:
  			LOG.error("Uknown hash algorithm: \""+hashAlgorithm+"\"");
  			break;
  	}
  	return null;
  }
docs: Returns the HashAlgorithm object matching the String.
  
  @param hashAlgorithm hash algorithm
  
  @return HashAlgorithm object corresponding to hash algorithm. Null if does not correspond to any algorithm.