set3_test.go

package cryptopals

import (
	"crypto/aes"
	"encoding/base64"
	"strings"
	"testing"
)

func TestChallenge17(t *testing.T) {
	pool := []string{
		"MDAwMDAwTm93IHRoYXQgdGhlIHBhcnR5IGlzIGp1bXBpbmc=",
		"MDAwMDAxV2l0aCB0aGUgYmFzcyBraWNrZWQgaW4gYW5kIHRoZSBWZWdhJ3MgYXJlIHB1bXBpbic=",
		"MDAwMDAyUXVpY2sgdG8gdGhlIHBvaW50LCB0byB0aGUgcG9pbnQsIG5vIGZha2luZw==",
		"MDAwMDAzQ29va2luZyBNQydzIGxpa2UgYSBwb3VuZCBvZiBiYWNvbg==",
		"MDAwMDA0QnVybmluZyAnZW0sIGlmIHlvdSBhaW4ndCBxdWljayBhbmQgbmltYmxl",
		"MDAwMDA1SSBnbyBjcmF6eSB3aGVuIEkgaGVhciBhIGN5bWJhbA==",
		"MDAwMDA2QW5kIGEgaGlnaCBoYXQgd2l0aCBhIHNvdXBlZCB1cCB0ZW1wbw==",
		"MDAwMDA3SSdtIG9uIGEgcm9sbCwgaXQncyB0aW1lIHRvIGdvIHNvbG8=",
		"MDAwMDA4b2xsaW4nIGluIG15IGZpdmUgcG9pbnQgb2g=",
		"MDAwMDA5aXRoIG15IHJhZy10b3AgZG93biBzbyBteSBoYWlyIGNhbiBibG93",
	}

	for _, plaintextBase64 := range pool {
		plaintextBytes, _ := base64.StdEncoding.DecodeString(plaintextBase64)

		encrypt, oracle := cbcPaddingOracle()
		iv, ct := encrypt(plaintextBase64)
		actualBytes := attackCBCPaddingOracle(iv, ct, oracle)

		if !strings.Contains(string(actualBytes), string(plaintextBytes)) {
			t.Errorf("expected %s to contain %s", actualBytes, plaintextBytes)
		}
	}
}

func TestChallenge18(t *testing.T) {
	key := "YELLOW SUBMARINE"
	nonce := make([]byte, len(key)/2)

	ctBase64 := "L77na/nrFsKvynd6HzOoG7GHTLXsTVu9qvY/2syLXzhPweyyMTJULu/6/kXX0KSvoOLSFQ=="
	ctBytes, _ := base64.StdEncoding.DecodeString(ctBase64)
	ptExpected := "Yo, VIP Let's kick it Ice, Ice, baby Ice, Ice, baby "

	cipher, err := aes.NewCipher([]byte(key))
	if err != nil {
		t.Errorf("failed to create AES cipher: %v", err)
	}

	pt, err := ctrDecrypt(ctBytes, nonce, cipher)
	if err != nil {
		t.Errorf("failed to decrypt: %v", err)
	}

	if string(pt) != ptExpected {
		t.Errorf("want %s, got %s", ptExpected, pt)
	}
}

func TestChallenge19(t *testing.T) {
	plaintexts := []string{
		"SSBoYXZlIG1ldCB0aGVtIGF0IGNsb3NlIG9mIGRheQ==",
		"Q29taW5nIHdpdGggdml2aWQgZmFjZXM=",
		"RnJvbSBjb3VudGVyIG9yIGRlc2sgYW1vbmcgZ3JleQ==",
		"RWlnaHRlZW50aC1jZW50dXJ5IGhvdXNlcy4=",
		"SSBoYXZlIHBhc3NlZCB3aXRoIGEgbm9kIG9mIHRoZSBoZWFk",
		"T3IgcG9saXRlIG1lYW5pbmdsZXNzIHdvcmRzLA==",
		"T3IgaGF2ZSBsaW5nZXJlZCBhd2hpbGUgYW5kIHNhaWQ=",
		"UG9saXRlIG1lYW5pbmdsZXNzIHdvcmRzLA==",
		"QW5kIHRob3VnaHQgYmVmb3JlIEkgaGFkIGRvbmU=",
		"T2YgYSBtb2NraW5nIHRhbGUgb3IgYSBnaWJl",
		"VG8gcGxlYXNlIGEgY29tcGFuaW9u",
		"QXJvdW5kIHRoZSBmaXJlIGF0IHRoZSBjbHViLA==",
		"QmVpbmcgY2VydGFpbiB0aGF0IHRoZXkgYW5kIEk=",
		"QnV0IGxpdmVkIHdoZXJlIG1vdGxleSBpcyB3b3JuOg==",
		"QWxsIGNoYW5nZWQsIGNoYW5nZWQgdXR0ZXJseTo=",
		"QSB0ZXJyaWJsZSBiZWF1dHkgaXMgYm9ybi4=",
		"VGhhdCB3b21hbidzIGRheXMgd2VyZSBzcGVudA==",
		"SW4gaWdub3JhbnQgZ29vZCB3aWxsLA==",
		"SGVyIG5pZ2h0cyBpbiBhcmd1bWVudA==",
		"VW50aWwgaGVyIHZvaWNlIGdyZXcgc2hyaWxsLg==",
		"V2hhdCB2b2ljZSBtb3JlIHN3ZWV0IHRoYW4gaGVycw==",
		"V2hlbiB5b3VuZyBhbmQgYmVhdXRpZnVsLA==",
		"U2hlIHJvZGUgdG8gaGFycmllcnM/",
		"VGhpcyBtYW4gaGFkIGtlcHQgYSBzY2hvb2w=",
		"QW5kIHJvZGUgb3VyIHdpbmdlZCBob3JzZS4=",
		"VGhpcyBvdGhlciBoaXMgaGVscGVyIGFuZCBmcmllbmQ=",
		"V2FzIGNvbWluZyBpbnRvIGhpcyBmb3JjZTs=",
		"SGUgbWlnaHQgaGF2ZSB3b24gZmFtZSBpbiB0aGUgZW5kLA==",
		"U28gc2Vuc2l0aXZlIGhpcyBuYXR1cmUgc2VlbWVkLA==",
		"U28gZGFyaW5nIGFuZCBzd2VldCBoaXMgdGhvdWdodC4=",
		"VGhpcyBvdGhlciBtYW4gSSBoYWQgZHJlYW1lZA==",
		"QSBkcnVua2VuLCB2YWluLWdsb3Jpb3VzIGxvdXQu",
		"SGUgaGFkIGRvbmUgbW9zdCBiaXR0ZXIgd3Jvbmc=",
		"VG8gc29tZSB3aG8gYXJlIG5lYXIgbXkgaGVhcnQs",
		"WWV0IEkgbnVtYmVyIGhpbSBpbiB0aGUgc29uZzs=",
		"SGUsIHRvbywgaGFzIHJlc2lnbmVkIGhpcyBwYXJ0",
		"SW4gdGhlIGNhc3VhbCBjb21lZHk7",
		"SGUsIHRvbywgaGFzIGJlZW4gY2hhbmdlZCBpbiBoaXMgdHVybiw=",
		"VHJhbnNmb3JtZWQgdXR0ZXJseTo=",
		"QSB0ZXJyaWJsZSBiZWF1dHkgaXMgYm9ybi4=",
	}

	key := "YELLOW SUBMARINE"
	nonce := make([]byte, len(key)/2)

	cipher, err := aes.NewCipher([]byte(key))
	if err != nil {
		t.Errorf("failed to create AES cipher: %v", err)
	}

	for _, pt := range plaintexts {
		ptBytes, err := base64.StdEncoding.DecodeString(pt)
		if err != nil {
			t.Errorf("failed to base64 plaintext %s", pt)
		}
		ct, err := ctrEncrypt(ptBytes, nonce, cipher)
		if err != nil {
			t.Errorf("failed to CTR encrypt plaintext %s", ptBytes)
		}
		t.Log(ct)
	}
}