Constant migration

Author

Bjarke Dahl Ebert, CRM

This document describes the changes to the constants.

The change is motivated by a Semper article.

Previously, constants were defined in CryptoConstants.java as static final ints. Now they have been moved to seperate classes, according to what kind of thing they specify. These classes are (with changes in constant names below them):

• KeyType.
• AsymmetricAlgorithm (superclass: KeyType).
• AsymmetricEncrAlgorithm (superclass: AsymmetricAlgorithm).
  • PK_RSA -> AsymmetricEncrAlgorithm.RSA
• ConventionalAlgorithm (superclass: Keytype).
  • CRYPT_DES -> ConventionalAlgorithm.DES
  • CRYPT_IDEA -> ConventionalAlgorithm.IDEA
  • CRYPT_3DES -> ConventionalAlgorithm.DES3
  ConventionalAlgorithm has a method getLength()to obtain the length of a key (in bytes).
• HashingAlgorithm
  • HASH_MD4 -> HashingAlgorithm.MD4
  • HASH_MD5 -> HashingAlgorithm.MD5
  • HASH_RIPEMD160 -> HashingAlgorithm.RIPEMD160
  • HASH_MDC2 -> HashingAlgorithm.MDC2
  • HASH_MDC4 -> HashingAlgorithm.MDC4
  • HASH_AR_DFP -> HashingAlgorithm.AR_DFP
  • HASH_SHS -> HashingAlgorithm.SHS
  HashingAlgorithm has a method getLength() to obtain the length of a hash value.
• KeyPadding
  • KEY_ENC_PAD0 -> KeyPadding.PAD0
  • KEY_ENC_PADRAND -> KeyPadding.PADRAND
• MACAlgorithm
  • ANSI_MAC -> MACAlgorithm.ANSI
  • ISO_MAC -> MACAlgorithm.ISO
  • RIPE_MAC -> MACAlgorithm.RIPE
• MessagePadding
  • ENCR_PAD_0PAD -> MessagePadding.0PAD
  • ENCR_PAD_ISO10126 -> MessagePadding.ISO10126
  • ENCR_PAD_NOPAD -> MessagePadding.NOPAD
• PublicKeySelection
  • RSA_EXP65537 -> PublicKeySelection.RSA_EXP65537
  • RSA_EXPRAND -> PublicKeySelection.RSA_EXPRAND
  • DSS_OLD_COMMON -> PublicKeySelection.DSS_OLD_COMMON
  • DSS_NEW_COMMON -> PublicKeySelection.DSS_NEW_COMMON
• SignAlgorithm
  • SIG_RSA -> SignAlgorithm.RSA
  • SIG_DSA -> SignAlgorithm.DSA
  • SIG_ISO9796 -> SignAlgorithm.ISO9796
  • SIG_RABIN -> SignAlgorithm.RABIN

Other changes:

• Import the relevant semper.crypto.* classes instead of semper.crypto.CryptoConstants.
• Remove the "implements CryptoConstants" from classes (as CryptoConstants should not be loaded, and is no longer an interface (it's a class now)).
• Note that all int declarations (of instance variables, formal arguments, etc.) which refers to constants has to be changed to the relevant class. Also, Integer casts used to make objects from constants (when inserting in lists, etc.) are no longer needed.
• A 0 was sometimes previously used to say "no constant specified". In these cases, use the null reference instead.
• Now switch/case program structures can mostly be elegantly avoided by adding instance variables and methods to relevant constant classes. Specifically, constant name lookup has been implemented this way in semper.util.constant. It implements toInt() and toString. See semper.util.constant.Constant for details.
• Constants are compared with .equals

Creation date: November 17, 1997 .