MD5.java

package cm4mmupdater.utils;

import cm4mmupdater.misc.Log;

import java.io.*;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class MD5 {
    private static final String TAG = "MD5";

    public static boolean checkMD5(String md5, File updateFile) {
        if (md5 == null || md5.equals("") || updateFile == null) {
            Log.e(TAG, "md5 String NULL or UpdateFile NULL");
            return false;
        }

        String calculatedDigest = calculateMD5(updateFile);

        if (calculatedDigest == null) {
            Log.e(TAG, "calculatedDigest NULL");
            return false;
        }

        Log.i(TAG, "Calculated digest: " + calculatedDigest);
        Log.i(TAG, "Provided digest: " + md5);

        return calculatedDigest.equalsIgnoreCase(md5);
    }

    public static String calculateMD5(File updateFile) {
        MessageDigest digest;
        try {
            digest = MessageDigest.getInstance("MD5");
        }
        catch (NoSuchAlgorithmException e) {
            Log.e(TAG, "Exception while getting Digest", e);
            return null;
        }
        InputStream is;
        try {
            is = new FileInputStream(updateFile);
        }
        catch (FileNotFoundException e) {
            Log.e(TAG, "Exception while getting FileInputStream", e);
            return null;
        }
        byte[] buffer = new byte[8192];
        int read;
        try {
            while ((read = is.read(buffer)) > 0) {
                digest.update(buffer, 0, read);
            }
            byte[] md5sum = digest.digest();
            BigInteger bigInt = new BigInteger(1, md5sum);
            String output = bigInt.toString(16);
            //Fill to 32 chars
            output = String.format("%32s", output).replace(' ', '0');
            return output;
        }
        catch (IOException e) {
            throw new RuntimeException("Unable to process file for MD5", e);
        }
        finally {
            try {
                is.close();
            }
            catch (IOException e) {
                Log.e(TAG, "Exception on closing MD5 input stream", e);
            }
        }
    }

    public static String getRecoveryMD5() {
        String MD5string = "";
        String recoveryFilename = "/dev/mtd/mtd1";
        try {
            Process p = Runtime.getRuntime().exec("su");
            OutputStream os = p.getOutputStream();
            os.write(("md5sum " + recoveryFilename).getBytes());
            os.flush();
            os.close();
            InputStream is = p.getInputStream();
            BufferedReader br = new BufferedReader(new InputStreamReader(is));
            String str = br.readLine();
            MD5string = str.split("  ")[0].trim();
            is.close();
            br.close();
            p.destroy();
        }
        catch (Exception e) {
            Log.e(TAG, "Exception on getting Recovery MD5", e);
            return null;
        }
        Log.i(TAG, "Recovery MD5: " + MD5string);
        return MD5string;
    }
}