Java

Encrypt File to PKCS7 .p7m

See more Encryption Examples

_LANGUAGE_ example to public-key encrypt a file creating a PKCS#7 .p7m file as output. Also demonstrates how to decrypt the .p7m to recover the original file. Chilkat2 Java

import com.chilkatsoft.chilkat2.Cert;
import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Crypt2;

public class ChilkatExample {

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

        Crypt2 crypt = new Crypt2();

        // Indicate the public-key encryption is to be used.
        // Do this by setting the encryption algorithm equal
        // to "PKI" (an acroynm for public-key infrastructure).
        crypt.setCryptAlgorithm("PKI");

        // Indicate the inner symmetric encryption algorithm to be used.
        // possible values are "aes", "des", "3des", and "rc2".
        // For this example, we'll use 256-bit AES encryption.
        crypt.setPkcs7CryptAlg("aes");
        crypt.setKeyLength(256);

        // To encrypt, only a certificate w/ public key is needed.
        // (The certificate w/ private key is required for decryption.)

        // The LoadFromFile method can load virtually any certificate format:
        // 1. DER encoded binary X.509 (.CER)
        // 2. Base-64 encoded X.509 (.CER)
        // 3. Cryptographic Message Syntax Standard - PKCS #7 Certificates (.P7B)
        // 4. PEM format
        Cert encryptCert = new Cert();
        try {
            encryptCert.loadFromFile("/Users/chilkat/testData/cer/acme.cer");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Tell the crypt object to use the certificate for encrypting:
        crypt.addEncryptCert(encryptCert);

        // Encrypt a file, producing a .p7m as output.
        // The input file is unchanged, the output .p7m contains the encrypted
        // contents of the input file.
        String inFile = "/Users/chilkat/testData/pdf/sample.pdf";
        String outFile = "/Users/chilkat/testData/p7m/sample.pdf.p7m";
        try {
            crypt.ckEncryptFile(inFile, outFile);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // For demonstration purposes, a different instance of the object will be used
        // for decryption.
        Crypt2 decrypt = new Crypt2();

        // To decrypt, the certificate w/ private key is required.  A PFX (also known
        // as PKCS#12) is a common secure container for certs and private keys.
        String pfxFilename = "/Users/chilkat/testData/pfx/acme.pfx";
        String pfxPassword = "secret";

        // Tell the component to look in the PFX file for certs and private keys.
        try {
            decrypt.addPfxSourceFile(pfxFilename, pfxPassword);

            // Tell the decrypt object that PKI (public key encryption) is to be used
            // for decryptiong.
            decrypt.setCryptAlgorithm("PKI");
            // There is no need to set the Pkcs7Alg or KeyLength because this information
            // is contained within the .p7m

            // Decrypt the .p7m
            inFile = "/Users/chilkat/testData/p7m/sample.pdf.p7m";
            outFile = "/Users/chilkat/testData/pdf/recovered.pdf";
            decrypt.ckDecryptFile(inFile, outFile);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

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