RSAの攻撃手法Common Modulus AttackをJuliaで書く

commonModulusAttack.jl

# Common Modulus Attack
function commonModulusAttack(N::BigInt, e1::Int, e2::Int, c1::BigInt, c2::BigInt)::BigInt
	s1, s2 = exEucild(e1, e2)
	v = s1 > 0 ? c1^s1 : 1/c1^(-s1) 
	w = s2 > 0 ? c2^s2 : 1/c2^(-s2) 
	return v * w
end

# Extended Eucildean algorithm
function exEucild(e1::Int, e2::Int)
	r = e1 > e2 ? [e1, e2] : [e2, e1]
	x = [1, 0]
	y = [0, 1]
	while true
		q = div(r[1], r[2])
		r3 = r[1]%r[2]
		r3 == 0 ? break : (r = [r[2], r3])
		x = [x[2], x[1] - x[2]q]
		y = [y[2], y[1] - y[2]q] 
	end
	return e1 > e2 ? [x[2], y[2]] : [y[2], x[2]]	
end