(Node.js) Compress and Encrypt a Large File (Low and Constant Memory Footprint)

See more Compression Examples

Demonstrates how to compress and encrypt a large file such that the memory footprint remains low and constant.

Note: This example requires Chilkat v9.5.0.99 or greater.

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    var compress = new chilkat.Compression();
    compress.Algorithm = "deflate";

    var success;

    // Set encryption params.
    // The possible values are the same as for the corresponding properties in the Chilkat Crypt2 class/object.
    // The encoded IV and Key must be specified as hex.
    var json = new chilkat.JsonObject();
    json.UpdateString("cryptAlgorithm","aes");
    json.UpdateString("cipherMode","cbc");
    json.UpdateInt("keyLength",128);
    json.UpdateInt("paddingScheme",0);
    json.UpdateString("encodedIV","000102030405060708090A0B0C0D0E0F");
    json.UpdateString("encodedKey","000102030405060708090A0B0C0D0E0F");

    // Do file-to-file compression+encryption in a single call.
    var inPath = "qa_data/largeFile.dat";
    var outPath = "c:/temp/qa_output/compressed_encrypted.dat";
    success = compress.CompressEncryptFile(json,inPath,outPath);
    if (success == false) {
        console.log(compress.LastErrorText);
        return;
    }

    // We can do file-to-file decrypt/decompress like this:
    var inPath2 = outPath;
    var outPath2 = "c:/temp/qa_output/restored.dat";
    success = compress.DecryptDecompressFile(json,inPath2,outPath2);
    if (success == false) {
        console.log(compress.LastErrorText);
        return;
    }

    // Note: The above decrypt + decompress is the equivalent of doing the same in these two steps:
    var crypt = new chilkat.Crypt2();
    crypt.CryptAlgorithm = "aes";
    crypt.CipherMode = "cbc";
    crypt.KeyLength = 128;
    crypt.PaddingScheme = 0;
    crypt.SetEncodedIV("000102030405060708090A0B0C0D0E0F","hex");
    crypt.SetEncodedKey("000102030405060708090A0B0C0D0E0F","hex");

    var decryptedPath = "c:/temp/qa_output/decrypted.dat";
    success = crypt.CkDecryptFile(inPath2,decryptedPath);
    if (success == false) {
        console.log(crypt.LastErrorText);
        return;
    }

    var outPath3 = "c:/temp/qa_output/restored_in_two_steps.dat";
    success = compress.DecompressFile(decryptedPath,outPath3);
    if (success == false) {
        console.log(compress.LastErrorText);
        return;
    }

    console.log("Success.");

}

chilkatExample();