Java

Convert Let's Encrypt PEM Files to a PFX

See more PFX/P12 Examples

Demonstrates how to convert the .pem files provided by Let's Encrypt to a single PFX. Chilkat2 Java

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Pfx;
import com.chilkatsoft.chilkat2.StringBuilder;

public class ChilkatExample {

    public static void main(String[] args) {
        // This example assumes the Chilkat API to have been previously unlocked.
        // See Global Unlock Sample for sample code.

        // Let's Encrypt provides four .pem files
        // 1. fullchain.pem
        // 2. privkey.pem
        // 3. cert.pem
        // 4. chain.pem

        // The cert.pem and chain.pem are redundant.
        // The fullchain.pem is composed of the cert.pem and chain.pem.

        // To convert the PEM's to a single .pfx, we don't need the redundant data.
        // The privkey.pem and fullchain.pem provide the required data.
        // We can ignore cert.pem and chain.pem (because those certs are already found in fullchain.pem).

        // We need a single .pem file that contains both the private key, the cert,
        // and the certs in the chain of authentication.
        // Let's combine priveky.pem and fullchain.pem into a single .pem

        StringBuilder sbPem = new StringBuilder();
        try {
            sbPem.loadFile("qa_data/pem/lets_encrypt/privkey.pem", "utf-8");
        } catch (ChilkatException e) {
            System.out.println("Failed to load privkey.pem");
            return;
        }

        // To be safe, append a blank line..
        sbPem.appendLine("", false);

        StringBuilder sbFullChainPem = new StringBuilder();
        try {
            sbFullChainPem.loadFile("qa_data/pem/lets_encrypt/fullchain.pem", "utf-8");
        } catch (ChilkatException e) {
            System.out.println("Failed to load fullchain.pem");
            return;
        }

        // Append the full cert chain PEM to the private key PEM.
        sbPem.appendSb(sbFullChainPem);

        // Load the combined PEM into a Chilkat PFX object.
        Pfx pfx = new Pfx();
        try {
            pfx.loadPem(sbPem.getAsString(), "no password required");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Write the PFX w/ a password.
        String pfxPassword = "secret";
        try {
            pfx.toFile(pfxPassword, "qa_output/sample.pfx");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("Success!");
    }
}