Java

Streaming Encryption by Encrypting in Chunks

See more Encryption Examples

Encrypt data in chunks. Chilkat2 Java

import com.chilkatsoft.chilkat2.Crypt2;
import com.chilkatsoft.chilkat2.StringBuilder;

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();

        crypt.setCryptAlgorithm("aes");
        crypt.setCipherMode("cbc");
        crypt.setKeyLength(128);

        crypt.setEncodedKey("000102030405060708090A0B0C0D0E0F", "hex");
        crypt.setEncodedIV("000102030405060708090A0B0C0D0E0F", "hex");

        crypt.setEncodingMode("hex");
        String txt1 = "The quick brown fox jumped over the lazy dog.\r\n";
        String txt2 = "-\r\n";
        String txt3 = "Done.\r\n";

        StringBuilder sbEncrypted = new StringBuilder();

        // Encrypt the 1st chunk:
        // (don't worry about feeding the data to the encryptor in
        // exact multiples of the encryption algorithm's block size.
        // Chilkat will buffer the data.)
        crypt.setFirstChunk(true);
        crypt.setLastChunk(false);
        sbEncrypted.append(crypt.encryptStringENC(txt1));

        // Encrypt the 2nd chunk
        crypt.setFirstChunk(false);
        crypt.setLastChunk(false);
        sbEncrypted.append(crypt.encryptStringENC(txt2));

        // Now encrypt N more chunks...
        // Remember -- we're doing this in CBC mode, so each call
        // to the encrypt method depends on the state from previous
        // calls...
        crypt.setFirstChunk(false);
        crypt.setLastChunk(false);
        for (int i = 0; i <= 4; i++) {
            sbEncrypted.append(crypt.encryptStringENC(txt1));
            sbEncrypted.append(crypt.encryptStringENC(txt2));
        }

        // Now encrypt the last chunk:
        crypt.setFirstChunk(false);
        crypt.setLastChunk(true);
        sbEncrypted.append(crypt.encryptStringENC(txt3));

        System.out.println(sbEncrypted.getAsString());

        // Now decrypt in one call.
        // (The data we're decrypting is both the first AND last chunk.)
        crypt.setFirstChunk(true);
        crypt.setLastChunk(true);
        String decryptedText = crypt.decryptStringENC(sbEncrypted.getAsString());

        System.out.println(decryptedText);

        // Note: You may decrypt in N chunks by setting the FirstChunk
        // and LastChunk properties prior to calling the Decrypt* methods.
    }
}