func Test4(t *testing.T) {
ciphertexts := make([][]byte, len(input4))
for i, input := range input4 {
// Decode ciphertext
ciphertext, err := encoding.DecodeHex([]byte(input))
if err != nil {
t.Error("Decoding", input, "failed")
}
ciphertexts[i] = ciphertext
}
// Attempt to find ciphertext most likely xor'd with a key of the same byte
ciphertext, closestByte := xorbyte.FindCiphertext(ciphertexts, xorbyte.EnglishScorer)
// Construct key from most likely byte
key := make([]byte, len(ciphertext))
for i := 0; i < len(key); i++ {
key[i] = closestByte
}
// Decrypt ciphertext
plaintext, _ := bits.Xor(ciphertext, key)
// output plaintext
if string(plaintext) != output4 {
t.Error(string(plaintext), "!=", output4)
}
}
func bytesAndScores(ciphertext []byte, scorer Scorer) chan byteAndScore {
ch := make(chan byteAndScore)
go func() {
key := make([]byte, len(ciphertext))
// Test each possible value of byte
for byteValue := 0; byteValue < 256; byteValue++ {
// Fill key with byteValue
for i := 0; i < len(key); i++ {
key[i] = byte(byteValue)
}
// Xor ciphertext with key (p == (p xor k) xor k)
plaintext, _ := bits.Xor(ciphertext, key)
// Frequency count
ch <- byteAndScore{
byte(byteValue),
scorer.Score(plaintext),
}
}
close(ch)
}()
return ch
}
func Test2(t *testing.T) {
raw1, err := encoding.DecodeHex([]byte(input2a))
if err != nil {
t.Error("Decoding", input2a, "failed")
}
raw2, err := encoding.DecodeHex([]byte(input2b))
if err != nil {
t.Error("Decoding", input2b, "failed")
}
result, err := bits.Xor(raw1, raw2)
if err != nil {
}
resultEncoded := encoding.EncodeHex(result)
if string(resultEncoded) != output2 {
t.Error(string(resultEncoded), "!=", output2)
}
}
func Test3(t *testing.T) {
// Decode ciphertext
ciphertext, err := encoding.DecodeHex([]byte(input3))
if err != nil {
t.Error("Decoding", input3, "failed")
}
// Attempt to find byte most likely xor'd with ciphertext
closestByte := xorbyte.FindByte(ciphertext, xorbyte.EnglishScorer)
// Construct key from most likely byte
key := make([]byte, len(ciphertext))
for i := 0; i < len(key); i++ {
key[i] = closestByte
}
// Decrypt ciphertext
plaintext, _ := bits.Xor(ciphertext, key)
// output plaintext
if string(plaintext) != output3 {
t.Error("Incorrect key chosen:", string(closestByte), string(plaintext))
}
}