This module provides a framework for message digest libraries.
You may want to look at OpenSSL::Digest as it supports more algorithms.
A cryptographic hash function is a procedure that takes data and returns a fixed bit string: the hash value, also known as digest. Hash functions are also called one-way functions, it is easy to compute a digest from a message, but it is infeasible to generate a message from a digest.
require 'digest' # Compute a complete digest Digest::SHA256.digest 'message' #=> "\xABS\n\x13\xE4Y..." sha256 = Digest::SHA256.new sha256.digest 'message' #=> "\xABS\n\x13\xE4Y..." # Other encoding formats Digest::SHA256.hexdigest 'message' #=> "ab530a13e459..." Digest::SHA256.base64digest 'message' #=> "q1MKE+RZFJgr..." # Compute digest by chunks md5 = Digest::MD5.new md5.update 'message1' md5 << 'message2' # << is an alias for update md5.hexdigest #=> "94af09c09bb9..." # Compute digest for a file sha256 = Digest::SHA256.file 'testfile' sha256.hexdigest
Additionally digests can be encoded in “bubble babble” format as a sequence of consonants and vowels which is more recognizable and comparable than a hexadecimal digest.
require 'digest/bubblebabble' Digest::SHA256.bubblebabble 'message' #=> "xopoh-fedac-fenyh-..."
See the bubble babble specification at http://web.mit.edu/kenta/www/one/bubblebabble/spec/jrtrjwzi/draft-huima-01.txt .
Different digest algorithms (or hash functions) are available:
- MD5: See RFC 1321 The MD5 Message-Digest Algorithm
RIPEMD-160: As Digest::RMD160. See http://homes.esat.kuleuven.be/~bosselae/ripemd160.html.
- SHA1: See FIPS 180 Secure Hash Standard.
- SHA2 family: See FIPS 180 Secure Hash Standard which defines the following algorithms:
The latest versions of the FIPS publications can be found here: http://csrc.nist.gov/publications/PubsFIPS.html.