Java

AES 256-bit CBC using PBKDF2 Generated Secret Key

See more Encryption Examples

First generates a 32-byte secret key using PBKDF2 (with HMAC-SHA256), and then uses the secret key to do 256-bit AES CBC mode decryption.

(Duplicates the following Java code)

public String decrypt(String strToDecrypt) {
        try  {
            // Read the initialization vector from the first bytes for the data
            byte [] rawData = Base64.getDecoder().decode(strToDecrypt);
            byte [] iv = new byte[Config.get().encryptionIVLength()];
            byte [] encryptedData = new byte[rawData.length - iv.length];
            System.arraycopy(rawData, 0, iv, 0, iv.length);
            System.arraycopy(rawData, iv.length, encryptedData, 0, encryptedData.length);
 
            IvParameterSpec ivspec = new IvParameterSpec(iv);
 
            SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256");
            KeySpec spec = new PBEKeySpec(secretKey.toCharArray(), salt.getBytes(), 65536, 256);
            SecretKey tmp = factory.generateSecret(spec);
            SecretKeySpec secretKey = new SecretKeySpec(tmp.getEncoded(), "AES");
 
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
            cipher.init(Cipher.DECRYPT_MODE, secretKey, ivspec);
            return new String(cipher.doFinal(encryptedData));
        }
        catch (Exception e) {
            log.error("Could not decrypt the string.", e);
        }
        return null;
    }

Chilkat2 Java

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();

        String password = "some arbitrary length password";
        // We have 8 bytes of salt encoded using hex.
        // (The salt can be any number of bytes, in any desired encoding such as base64, hex, etc.)
        String saltHex = "0102030405060708";

        // Generate the 256-bit (32-byte) AES secret key we'll use to decrypt.
        int iterationCount = 65536;
        int outputKeyBitLen = 256;
        String secretKeyHex = crypt.pbkdf2(password, "utf-8", "sha256", saltHex, iterationCount, outputKeyBitLen, "hex");

        // Setup for 256-bit AES CBC decryption.
        crypt.setCryptAlgorithm("aes");
        crypt.setKeyLength(256);
        crypt.setCipherMode("cbc");
        crypt.setPaddingScheme(0);

        // The IV for AES is 16 bytes.
        String iv = "000102030405060708090A0B0C0D0E0F";
        crypt.setEncodedIV(iv, "hex");

        // Set the secret key for 256-bit AES.
        crypt.setEncodedKey(secretKeyHex, "hex");

        // AES decrypt
        // assume our string to decrypt is base64
        String strToDecrypt = "....";
        crypt.setEncodingMode("base64");
        String decryptedStr = crypt.decryptStringENC(strToDecrypt);

        System.out.println(decryptedStr);
    }
}