This module provides a framework for message digest libraries.
You may want to look at OpenSSL::Digest as it supports support more algorithms.
A cryptographic hash function is a procedure that takes data and return 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.
Example
require 'digest' # Compute a complete digest sha256 = Digest::SHA256.new digest = sha256.digest message # Compute digest by chunks sha256 = Digest::SHA256.new sha256.update message1 sha256 << message2 # << is an alias for update digest = sha256.digest
Digest algorithms
Different digest algorithms (or hash functions) are available :
- HMAC
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See FIPS PUB 198 The Keyed-Hash Message Authentication Code (HMAC)
- RIPEMD-160
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(as Digest::RMD160) see homes.esat.kuleuven.be/~bosselae/ripemd160.html
- SHA1
-
See FIPS 180 Secure Hash Standard
- SHA2 family
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See FIPS 180 Secure Hash Standard which defines the following algorithms:
-
SHA512
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SHA384
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SHA256
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The latest versions of the FIPS publications can be found here: csrc.nist.gov/publications/PubsFIPS.html
Additionally Digest::BubbleBabble encodes a digest as a sequence of consonants and vowels which is more recognizable and comparable than a hexadecimal digest. See en.wikipedia.org/wiki/Bubblebabble