(JavaScript) Encrypt a File to a PKCS7 (CMS) Message

Shows how to encrypt a file into a PKCS7 encrypted message using the recipient's certificate. Public-key encryption requires no private key. However, the recipient's private key is necessary for decryption.

Note

This example is intended for running within a Chilkat.Js embedded JavaScript engine. All Chilkat JavaScript examples require Chilkat v11.4.0 or greater.

var success = false;

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

var crypt = new CkCrypt2();

// Load the recipient's digital certificate. 
// We don't need the private key for encryption.
// Only the public key is needed (which is included in a certificate).
var cert1 = new CkCert();
success = cert1.LoadFromFile("qa_data/user1/cert_user1.pem");
// Assume success for the example, but make sure your application checks for success/failure...
crypt.SetEncryptCert(cert1);

// Indicate that we want PKI encryption (i.e. public-key infrastructure)
// to produce a CMS message (Cryptographic Message Syntax/PKCS7),
// that is be created with RSAES-OAEP padding, SHA256, and AES-256 for the
// bulk encryption.
crypt.CryptAlgorithm = "pki";
crypt.Pkcs7CryptAlg = "aes";
crypt.KeyLength = 256;
crypt.OaepHash = "sha256";
crypt.OaepPadding = true;

// Load the file to be encrypted...
var fileData = new CkBinData();
success = fileData.LoadFile("qa_data/jpg/penguins.jpg");
// Your app should check for success/failure..

// Encrypt the data.  The contents of the fileData object are replaced with the PKCS7 encrypted message.
success = crypt.EncryptBd(fileData);
if (success !== true) {
    console.log(crypt.LastErrorText);
    return;
}

// Save the PKCS7 encrypted message to a file..
success = fileData.WriteFile("qa_output/pkcs7_encrypted.p7");

console.log("OK.");