Ruby SHA2類用法及代碼示例

SHA256、SHA384 和 SHA512 的元摘要提供程序類。

FIPS 180-2 說明了 SHA2 係列的摘要算法。它定義了三種算法：

• 一種適用於 512 位塊並返回 256 位摘要 (SHA256) 的方法，

• 一種適用於 1024 位塊並返回 384 位摘要 (SHA384) 的方法，

• 一種適用於 1024 位塊並返回 512 位摘要 (SHA512)。

例子

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..."