(Node.js) Load .eml and Decrypt (smime.p7m)

Loads an encrypted email from a .eml file and decrypts using certificate w/ private key found in a .p12 (or .pfx) file.

The Content-Type and Content-Disposition email headers of the email to be decrypted look similar to this:

Content-Type: application/x-pkcs7-mime; smime-type=enveloped-data;
	name="smime.p7m"
Content-Disposition: attachment; filename="smime.p7m"

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() {

    var email = new chilkat.Email();

    var success;

    // Add a PFX (or .p12) to be used for decryption
    success = email.AddPfxSourceFile("myCert.p12","passwordForP12");
    if (success !== true) {
        console.log(email.LastErrorText);
        return;
    }

    // Loading the .eml automatically decrypts.
    success = email.LoadEml("encrypted.eml");
    if (success !== true) {
        console.log(email.LastErrorText);
        return;
    }

    // The email now exists as it was prior to encryption.
    // Your app may access the email's subject, body, attachments,
    // etc. using the Chilkat Email API...

    // Save the decrypted email:
    success = email.SaveEml("decrypted.eml");
    if (success !== true) {
        console.log(email.LastErrorText);
        return;
    }

    console.log("Success.");

}

chilkatExample();