aead-stream/dist/encrypt.js

Authenticated encryption on arbitrary large files

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.encrypt = void 0;
const crypto_1 = require("crypto");
const chunkify_1 = require("./chunkify");
const options_1 = require("./options");
async function* encrypt(key, plaintext, options = options_1.defaultOptions) {
    const { algorithm, authTagLength, nonceLength, associatedData } = options;
    const chunkSize = options.chunkSize - nonceLength - authTagLength;
    let chunkIndex = 0;
    for await (const chunk of (0, chunkify_1.chunkify)(chunkSize, plaintext)) {
        const nonce = (0, crypto_1.randomBytes)(nonceLength);
        let cipher = (0, crypto_1.createCipheriv)(algorithm, key, nonce, {
            authTagLength,
        });
        let aad = Buffer.from([chunkIndex++]);
        if (associatedData) {
            aad = Buffer.concat([aad, associatedData]);
        }
        cipher.setAAD(aad, {
            plaintextLength: chunk.length,
        });
        const ciphertext = cipher.update(chunk);
        cipher.final();
        const authTag = cipher.getAuthTag();
        yield Buffer.concat([nonce, ciphertext, authTag]);
    }
}
exports.encrypt = encrypt;