namespace CryptoFile

module UnitTests =
    open System.IO
    open System.Text
    open System.Security.Cryptography
    open Crypto

    let testRSA () =
        let kpub, kpriv = generateRSAKeysPair ()
        let plaintext = "Are you from the past?"
        let cipherdata = encryptRSA kpub (Encoding.UTF8.GetBytes plaintext)
        let decryptedData = decryptRSA kpriv cipherdata
        let decryptedText = Encoding.UTF8.GetString decryptedData

        assert (plaintext = decryptedText)
        printfn "testRSA OK"

    let testRSASignature () =
        let kpub, kpriv = generateRSAKeysPair ()
        let plaintext = "Lightspeed is too slow. We'll have to go right to ludicrous speed!"
        use sha256 = new SHA256Managed ()
        let signature = signRSA kpriv (sha256.ComputeHash (Encoding.UTF8.GetBytes plaintext))
        assert verifySignRSA kpub (sha256.ComputeHash (Encoding.UTF8.GetBytes plaintext)) signature
        assert not (verifySignRSA kpub (sha256.ComputeHash (Encoding.UTF8.GetBytes "Hello!")) signature)
        printfn "testRSASignature OK"

    let testAES () =
        let plaintext = "There is no place like 127.0.0.1"
        use memory = new MemoryStream ()
        let key = Crypto.rand 16
        let iv = Crypto.rand 16

        let input = encryptAES key iv memory
        use sw = new StreamWriter (input)
        sw.Write plaintext
        sw.Flush ()
        input.FlushFinalBlock ()

        memory.Position <- 0L
        let output = decryptAES key iv memory
        use sr = new StreamReader (output)

        assert (sr.ReadToEnd () = plaintext)
        printfn "testAES OK"

    let runAllUnitTests () =
        testRSA ()
        testRSASignature ()
        testAES ()