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require 'openssl'
module Net
module NTLM
begin
OpenSSL::Cipher.new("rc4")
rescue
# libssl-3.0+ doesn't support legacy Rc4 -> use our own implementation
class Rc4
def initialize(str)
raise ArgumentError, "RC4: Key supplied is blank" if str.eql?('')
initialize_state(str)
@q1, @q2 = 0, 0
end
def encrypt(text)
text.each_byte.map do |b|
@q1 = (@q1 + 1) % 256
@q2 = (@q2 + @state[@q1]) % 256
@state[@q1], @state[@q2] = @state[@q2], @state[@q1]
b ^ @state[(@state[@q1] + @state[@q2]) % 256]
end.pack("C*")
end
private
# The initial state which is then modified by the key-scheduling algorithm
INITIAL_STATE = (0..255).to_a
# Performs the key-scheduling algorithm to initialize the state.
def initialize_state(key)
i = j = 0
@state = INITIAL_STATE.dup
key_length = key.length
while i < 256
j = (j + @state[i] + key.getbyte(i % key_length)) % 256
@state[i], @state[j] = @state[j], @state[i]
i += 1
end
end
end
else
# Openssl/libssl provides RC4, so we can use it.
class Rc4
def initialize(str)
@ci = OpenSSL::Cipher.new("rc4")
@ci.key = str
end
def encrypt(text)
@ci.update(text) + @ci.final
end
end
end
end
end
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