crypto.js

"use strict";
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Object.defineProperty(exports, "__esModule", { value: true });
exports.hkdf = exports.sha256 = exports.hmacSign = exports.aesEncrypWithIV = exports.aesEncrypt = exports.aesDecryptWithIV = exports.aesDecrypt = exports.aesDecryptGCM = exports.aesEncryptGCM = exports.signedKeyPair = exports.Curve = exports.generateSignalPubKey = void 0;
const crypto_1 = require("crypto");
const futoin_hkdf_1 = __importDefault(require("futoin-hkdf"));
const libsignal = __importStar(require("libsignal"));
const Defaults_1 = require("../Defaults");
/** prefix version byte to the pub keys, required for some curve crypto functions */
const generateSignalPubKey = (pubKey) => (pubKey.length === 33
    ? pubKey
    : Buffer.concat([Defaults_1.KEY_BUNDLE_TYPE, pubKey]));
exports.generateSignalPubKey = generateSignalPubKey;
exports.Curve = {
    generateKeyPair: () => {
        const { pubKey, privKey } = libsignal.curve.generateKeyPair();
        return {
            private: Buffer.from(privKey),
            // remove version byte
            public: Buffer.from(pubKey.slice(1))
        };
    },
    sharedKey: (privateKey, publicKey) => {
        const shared = libsignal.curve.calculateAgreement((0, exports.generateSignalPubKey)(publicKey), privateKey);
        return Buffer.from(shared);
    },
    sign: (privateKey, buf) => (libsignal.curve.calculateSignature(privateKey, buf)),
    verify: (pubKey, message, signature) => {
        try {
            libsignal.curve.verifySignature((0, exports.generateSignalPubKey)(pubKey), message, signature);
            return true;
        }
        catch (error) {
            return false;
        }
    }
};
const signedKeyPair = (identityKeyPair, keyId) => {
    const preKey = exports.Curve.generateKeyPair();
    const pubKey = (0, exports.generateSignalPubKey)(preKey.public);
    const signature = exports.Curve.sign(identityKeyPair.private, pubKey);
    return { keyPair: preKey, signature, keyId };
};
exports.signedKeyPair = signedKeyPair;
const GCM_TAG_LENGTH = 128 >> 3;
/**
 * encrypt AES 256 GCM;
 * where the tag tag is suffixed to the ciphertext
 * */
function aesEncryptGCM(plaintext, key, iv, additionalData) {
    const cipher = (0, crypto_1.createCipheriv)('aes-256-gcm', key, iv);
    cipher.setAAD(additionalData);
    return Buffer.concat([cipher.update(plaintext), cipher.final(), cipher.getAuthTag()]);
}
exports.aesEncryptGCM = aesEncryptGCM;
/**
 * decrypt AES 256 GCM;
 * where the auth tag is suffixed to the ciphertext
 * */
function aesDecryptGCM(ciphertext, key, iv, additionalData) {
    const decipher = (0, crypto_1.createDecipheriv)('aes-256-gcm', key, iv);
    // decrypt additional adata
    const enc = ciphertext.slice(0, ciphertext.length - GCM_TAG_LENGTH);
    const tag = ciphertext.slice(ciphertext.length - GCM_TAG_LENGTH);
    // set additional data
    decipher.setAAD(additionalData);
    decipher.setAuthTag(tag);
    return Buffer.concat([decipher.update(enc), decipher.final()]);
}
exports.aesDecryptGCM = aesDecryptGCM;
/** decrypt AES 256 CBC; where the IV is prefixed to the buffer */
function aesDecrypt(buffer, key) {
    return aesDecryptWithIV(buffer.slice(16, buffer.length), key, buffer.slice(0, 16));
}
exports.aesDecrypt = aesDecrypt;
/** decrypt AES 256 CBC */
function aesDecryptWithIV(buffer, key, IV) {
    const aes = (0, crypto_1.createDecipheriv)('aes-256-cbc', key, IV);
    return Buffer.concat([aes.update(buffer), aes.final()]);
}
exports.aesDecryptWithIV = aesDecryptWithIV;
// encrypt AES 256 CBC; where a random IV is prefixed to the buffer
function aesEncrypt(buffer, key) {
    const IV = (0, crypto_1.randomBytes)(16);
    const aes = (0, crypto_1.createCipheriv)('aes-256-cbc', key, IV);
    return Buffer.concat([IV, aes.update(buffer), aes.final()]); // prefix IV to the buffer
}
exports.aesEncrypt = aesEncrypt;
// encrypt AES 256 CBC with a given IV
function aesEncrypWithIV(buffer, key, IV) {
    const aes = (0, crypto_1.createCipheriv)('aes-256-cbc', key, IV);
    return Buffer.concat([aes.update(buffer), aes.final()]); // prefix IV to the buffer
}
exports.aesEncrypWithIV = aesEncrypWithIV;
// sign HMAC using SHA 256
function hmacSign(buffer, key, variant = 'sha256') {
    return (0, crypto_1.createHmac)(variant, key).update(buffer).digest();
}
exports.hmacSign = hmacSign;
function sha256(buffer) {
    return (0, crypto_1.createHash)('sha256').update(buffer).digest();
}
exports.sha256 = sha256;
// HKDF key expansion
function hkdf(buffer, expandedLength, info) {
    return (0, futoin_hkdf_1.default)(!Buffer.isBuffer(buffer) ? Buffer.from(buffer) : buffer, expandedLength, info);
}
exports.hkdf = hkdf;