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# frozen_string_literal: true
# This code was extracted from https://github.com/Solistra/ruby-digest which is under public domain
module Bundler
module Digest
# The initial constant values for the 32-bit constant words A, B, C, D, and
# E, respectively.
SHA1_WORDS = [0x67452301, 0xEFCDAB89, 0x98BADCFE, 0x10325476, 0xC3D2E1F0].freeze
# The 8-bit field used for bitwise `AND` masking. Defaults to `0xFFFFFFFF`.
SHA1_MASK = 0xFFFFFFFF
class << self
def sha1(string)
unless string.is_a?(String)
raise TypeError, "can't convert #{string.class.inspect} into String"
end
buffer = string.b
words = SHA1_WORDS.dup
generate_split_buffer(buffer) do |chunk|
w = []
chunk.each_slice(4) do |a, b, c, d|
w << (((a << 8 | b) << 8 | c) << 8 | d)
end
a, b, c, d, e = *words
(16..79).each do |i|
w[i] = SHA1_MASK & rotate((w[i-3] ^ w[i-8] ^ w[i-14] ^ w[i-16]), 1)
end
0.upto(79) do |i|
case i
when 0..19
f = ((b & c) | (~b & d))
k = 0x5A827999
when 20..39
f = (b ^ c ^ d)
k = 0x6ED9EBA1
when 40..59
f = ((b & c) | (b & d) | (c & d))
k = 0x8F1BBCDC
when 60..79
f = (b ^ c ^ d)
k = 0xCA62C1D6
end
t = SHA1_MASK & (SHA1_MASK & rotate(a, 5) + f + e + k + w[i])
a, b, c, d, e = t, a, SHA1_MASK & rotate(b, 30), c, d # rubocop:disable Style/ParallelAssignment
end
mutated = [a, b, c, d, e]
words.map!.with_index {|word, index| SHA1_MASK & (word + mutated[index]) }
end
words.pack("N*").unpack("H*").first
end
private
def generate_split_buffer(string, &block)
size = string.bytesize * 8
buffer = string.bytes << 128
buffer << 0 while buffer.size % 64 != 56
buffer.concat([size].pack("Q>").bytes)
buffer.each_slice(64, &block)
end
def rotate(value, spaces)
value << spaces | value >> (32 - spaces)
end
end
end
end
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