cryptopals_set01_test.go

package cryptopals_test

import (
	"bufio"
	"fmt"
	"os"

	"github.com/kieron-pivotal/cryptopals/conversion"
	"github.com/kieron-pivotal/cryptopals/operations"

	. "github.com/onsi/ginkgo"
	. "github.com/onsi/gomega"
)

var _ = Describe("Crytopals Set 01", func() {
	It("question 1", func() {
		bytes, err := conversion.HexToBytes("49276d206b696c6c696e6720796f757220627261696e206c696b65206120706f69736f6e6f7573206d757368726f6f6d")
		Expect(err).NotTo(HaveOccurred())
		Expect(conversion.BytesToBase64(bytes)).
			To(Equal("SSdtIGtpbGxpbmcgeW91ciBicmFpbiBsaWtlIGEgcG9pc29ub3VzIG11c2hyb29t"))

		fmt.Println(string(bytes))
	})

	It("question 2", func() {
		hex1 := "1c0111001f010100061a024b53535009181c"
		hex2 := "686974207468652062756c6c277320657965"
		expectedXor := "746865206b696420646f6e277420706c6179"

		bytes1, err := conversion.HexToBytes(hex1)
		Expect(err).NotTo(HaveOccurred())
		bytes2, err := conversion.HexToBytes(hex2)
		Expect(err).NotTo(HaveOccurred())

		xoredBytes := operations.Xor(bytes1, bytes2)
		Expect(conversion.BytesToHex(xoredBytes)).To(Equal(expectedXor))

		fmt.Println(string(bytes2))
		fmt.Println(string(xoredBytes))
	})

	It("question 3", func() {
		hex := "1b37373331363f78151b7f2b783431333d78397828372d363c78373e783a393b3736"
		bytes, err := conversion.HexToBytes(hex)
		Expect(err).NotTo(HaveOccurred())
		clear, b, _ := operations.SingleCharXorDecrypt(bytes)
		Expect(clear).ToNot(BeEmpty())
		fmt.Println(clear, b)
	})

	It("question 4", func() {
		file, err := os.Open("./assets/01_04.txt")
		Expect(err).NotTo(HaveOccurred())
		defer file.Close()

		minScore := 1e20
		minTxt := ""
		minLine := 0

		scanner := bufio.NewScanner(file)
		line := 0
		var xorByte byte

		for scanner.Scan() {
			line++
			hex := scanner.Text()
			bytes, err := conversion.HexToBytes(hex)
			Expect(err).NotTo(HaveOccurred())
			txt, xb, score := operations.SingleCharXorDecrypt(bytes)

			if score < minScore {
				minScore = score
				minTxt = txt
				minLine = line
				xorByte = xb
			}
		}

		Expect(minTxt).ToNot(BeEmpty())
		fmt.Println(minTxt, xorByte, minLine)
	})

	It("question 5", func() {
		inBytes := []byte(`Burning 'em, if you ain't quick and nimble
I go crazy when I hear a cymbal`)
		expectedOut := `0b3637272a2b2e63622c2e69692a23693a2a3c6324202d623d63343c2a26226324272765272a282b2f20430a652e2c652a3124333a653e2b2027630c692b20283165286326302e27282f`
		xor := []byte("ICE")

		xored := operations.Xor(inBytes, xor)
		outHex := conversion.BytesToHex(xored)

		Expect(outHex).To(Equal(expectedOut))
	})

	It("question 6", func() {
		bytes, err := conversion.ReadBase64File("./assets/01_06.txt")
		Expect(err).NotTo(HaveOccurred())

		clear, key := operations.RepeatingXorDecrypt(bytes)
		Expect(clear).To(ContainSubstring("funky"))

		fmt.Printf("Key: '%s'\n", key)
		fmt.Println(clear)

	})

	It("question 7", func() {
		bytes, err := conversion.ReadBase64File("./assets/01_07.txt")
		Expect(err).NotTo(HaveOccurred())

		clear, err := operations.AES128ECBDecode(bytes, []byte("YELLOW SUBMARINE"))
		Expect(err).NotTo(HaveOccurred())

		clearStr := string(clear)
		Expect(clearStr).To(ContainSubstring("funky"))

		fmt.Println(clearStr)
	})

	It("question 8", func() {
		file, err := os.Open("./assets/01_08.txt")
		Expect(err).NotTo(HaveOccurred())
		defer file.Close()

		scanner := bufio.NewScanner(file)
		line := 0
		for scanner.Scan() {
			line++
			hex := scanner.Text()
			if operations.DetectAES128ECB(string(hex)) {
				break
			}
		}
		Expect(line).To(Equal(133))

	})
})