rsa.jl

#Pkg.add("Primes")
using Primes

function genBigPrime()
    prime = 0
    while prime == 0
        #possiblePrime = rand(BigInt(1e+50):BigInt(1e+100))
        possiblePrime = Int(rand(1e+2:1e+4))
        if isprime(possiblePrime)
            prime = possiblePrime
        end
    end
    prime
end

mdc(a, b) = b == 0 ? a : mdc(b, a % b)

p, q = genBigPrime(), genBigPrime()

N = p*q

ϕ = (p-1) * (q-1)

E = begin
    coprime = 0
    c = 2
    while coprime == 0
        if mdc(c, ϕ) == 1
            coprime = c
        end
        c += 1
    end
    coprime
end

D = invmod(E, ϕ)

println(repeat("*", 80))

println("parametros:
p, q = $p, $q
N = $N
ϕ = $ϕ
E = $E
D = $D")

println(repeat("*", 80))

println("digite uma mensagem:")
msgEnc = [BigInt(i)^E % N for i in readline(STDIN)]

println(repeat("*", 80))

println("\nMensagem Encriptada: $(msgEnc |> join)")

msgDec = map(x->Char(x^D % N), msgEnc) |> join
println("Mensagem Decriptada: $msgDec")

println(repeat("*", 80))