android - 我如何加密 Android SQLite 数据库中的特定列数据。使用 SQLCipher 实用程序

Question

我在 android 中有一个 SQLite 数据库，我只想加密该数据库中的几列。我发现它可以与整个数据库一起加密，但我只需要加密几列数据。

Answer 1

你可以使用这个类来加密和解密你的数据:

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import android.util.Base64;

public class SimpleCrypto {

    private String charsetName = "UTF8";
    private String algorithm = "DES";
    private int base64Mode = Base64.DEFAULT;

    public String getCharsetName() {
        return charsetName;
    }

    public void setCharsetName(String charsetName) {
        this.charsetName = charsetName;
    }

    public String getAlgorithm() {
        return algorithm;
    }

    public void setAlgorithm(String algorithm) {
        this.algorithm = algorithm;
    }

    public int getBase64Mode() {
        return base64Mode;
    }

    public void setBase64Mode(int base64Mode) {
        this.base64Mode = base64Mode;
    }

    public String encrypt(String key, String data) {
        if (key == null || data == null)
            return null;
        try {
            DESKeySpec desKeySpec = new DESKeySpec(key.getBytes(charsetName));
            SecretKeyFactory secretKeyFactory = SecretKeyFactory.getInstance(algorithm);
            SecretKey secretKey = secretKeyFactory.generateSecret(desKeySpec);
            byte[] dataBytes = data.getBytes(charsetName);
            Cipher cipher = Cipher.getInstance(algorithm);
            cipher.init(Cipher.ENCRYPT_MODE, secretKey);
            return Base64.encodeToString(cipher.doFinal(dataBytes), base64Mode);
        } catch (Exception e) {
            return null;
        }
    }

    public String decrypt(String key, String data) {
        if (key == null || data == null)
            return null;
        try {
            byte[] dataBytes = Base64.decode(data, base64Mode);
            DESKeySpec desKeySpec = new DESKeySpec(key.getBytes(charsetName));
            SecretKeyFactory secretKeyFactory = SecretKeyFactory.getInstance(algorithm);
            SecretKey secretKey = secretKeyFactory.generateSecret(desKeySpec);
            Cipher cipher = Cipher.getInstance(algorithm);
            cipher.init(Cipher.DECRYPT_MODE, secretKey);
            byte[] dataBytesDecrypted = (cipher.doFinal(dataBytes));
            return new String(dataBytesDecrypted);
        } catch (Exception e) {
            return null;
        }
    }
}

您可以像这样加密您的数据:

private SimpleCrypto simpleCrypto = new SimpleCrypto();

String MasterPassword = "qssfFs32fFwada";

String encryptedText = simpleCrypto.encrypt(MasterPassword, "Hello World");
Log.i(encryptedText, encryptedText);

然后你可以像这样解密它们:

String decryptedText = decrypt(MasterPassword, encryptedText);
Log.i(decryptedText, decryptedText);