challenge19.ts

import * as crypto from 'crypto';
import {AES_128_BLOCK_LENGTH_BYTES} from '../set1/challenge7';
import {aes128CtrEncrypt} from './challenge18';

export interface CtrEncryptionOracle {
    encryptCiphertextsWithFixedNonceAndRandomKey(): Array<Buffer>;
}

export const plaintexts = [
    '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='
];

export function createCtrEncryptionOracle(plaintexts: ReadonlyArray<string>): CtrEncryptionOracle {
    function ctrEncryptionOracle(): Array<Buffer> {
        const randomAESKey = crypto.randomBytes(AES_128_BLOCK_LENGTH_BYTES);
        const fixedNonce = Buffer.alloc(AES_128_BLOCK_LENGTH_BYTES).fill(0x0);
        const ciphertexts: Array<Buffer> = [];
        plaintexts.forEach((base64EncodedPlaintext: string) => {
            const plaintext = Buffer.from(base64EncodedPlaintext, 'base64');
            const ciphertext = aes128CtrEncrypt(plaintext, randomAESKey, fixedNonce);
            ciphertexts.push(ciphertext);
        });
        return ciphertexts;
    }
    return {
        encryptCiphertextsWithFixedNonceAndRandomKey: ctrEncryptionOracle
    };
}