project.

  ext/digest:
    This module provides the module Digest and the abstract class
    Digest::Base.

  ext/digest/md5 (which obsoletes ext/md5):
    This module provides the class Digest::MD5 which implements the
    MD5 Message-Digest Algorithm.

  ext/digest/rmd160:
    This module provides the class Digest::RMD160 which implements the
    RIPEMD-160 cryptographic hash function.

  ext/digest/sha1 (which obsoletes ext/sha1):
    This module provides the class Digest::SHA1 which implements the
    SHA-1 Secure Hash Algorithm.

  ext/digest/sha2:
    This module provides the classes Digest::SHA256, Digest::SHA384
    and Digest::SHA512 which implement the SHA-256, SHA-384 and
    SHA-512 Secure Hash Algorithms, respectively.

  lib/md5.rb, lib/sha1.rb:
    These files are provided for backward compatibility.

All these classes have the common API, which previously ext/md5 and
ext/sha1 modules provided.  While the new API keeps 100% backward
compatibility, it has been enriched with several utility methods.

Read digest.txt for further details.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@1609 b2dd03c8-39d4-4d8f-98ff-823fe69b080e