class Digest::SHA2

A meta digest provider class for SHA256, SHA384 and SHA512.

FIPS 180-2 describes SHA2 family of digest algorithms. It defines three algorithms: * one which works on chunks of 512 bits and returns a 256-bit digest (SHA256), * one which works on chunks of 1024 bits and returns a 384-bit digest (SHA384), * and one which works on chunks of 1024 bits and returns a 512-bit digest (SHA512).

Examples

require 'digest'

# Compute a complete digest
Digest::SHA2.hexdigest 'abc'          # => "ba7816bf8..."
Digest::SHA2.new(256).hexdigest 'abc' # => "ba7816bf8..."
Digest::SHA256.hexdigest 'abc'        # => "ba7816bf8..."

Digest::SHA2.new(384).hexdigest 'abc' # => "cb00753f4..."
Digest::SHA384.hexdigest 'abc'        # => "cb00753f4..."

Digest::SHA2.new(512).hexdigest 'abc' # => "ddaf35a19..."
Digest::SHA512.hexdigest 'abc'        # => "ddaf35a19..."

# Compute digest by chunks
sha2 = Digest::SHA2.new               # =>#<Digest::SHA2:256>
sha2.update "ab"
sha2 << "c"                           # alias for #update
sha2.hexdigest                        # => "ba7816bf8..."

# Use the same object to compute another digest
sha2.reset
sha2 << "message"
sha2.hexdigest                        # => "ab530a13e..."

Public Class Methods

new

(?256 | 384 | 512 bitlen) → void

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.0.3/stdlib/digest/0/digest.rbs, line 520
def initialize: (?(256 | 384 | 512) bitlen) -> void

Create a new SHA2 hash object with a given bit length.

Valid bit lengths are 256, 384 and 512.

Public Instance Methods

(String) → self

Alias for: update

block_length

() → Integer

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.0.3/stdlib/digest/0/digest.rbs, line 561
def block_length: () -> Integer

Return the block length of the digest in bytes.

Digest::SHA256.new.block_length * 8
# => 512
Digest::SHA384.new.block_length * 8
# => 1024
Digest::SHA512.new.block_length * 8
# => 1024

digest_length

() → Integer

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.0.3/stdlib/digest/0/digest.rbs, line 579
def digest_length: () -> Integer

Return the length of the hash value (the digest) in bytes.

Digest::SHA256.new.digest_length * 8
# => 256
Digest::SHA384.new.digest_length * 8
# => 384
Digest::SHA512.new.digest_length * 8
# => 512

For example, digests produced by Digest::SHA256 will always be 32 bytes (256 bits) in size.

initialize_copy

(untyped) → untyped

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.0.3/stdlib/digest/0/digest.rbs, line 581
def initialize_copy: (untyped) -> untyped

reset

() → self

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.0.3/stdlib/digest/0/digest.rbs, line 528
def reset: () -> self

Reset the digest to the initial state and return self.

update

(String) → self

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.0.3/stdlib/digest/0/digest.rbs, line 537
def update: (String) -> self

Update the digest using a given string and return self.

Also aliased as: <<