On successful download of the update zip file from server we must verify the cryptographic signature of the downloaded update file, and then we can install it as follows: It will reboot the device in recovery mode, where recovery console will first verify the signature of the file then execute the updater script of that update zip file, which wi…

Verify&Install.java

try {
    File otafileloc = new File("/cache/update.zip");
    // Verify the cryptographic signature before installing it.  
    RecoverySystem.verifyPackage(otafileloc, null, null);
    // Reboots the device into recovery mode to install the update package.
    	RecoverySystem.installPackage(getApplicationContext(), otafileloc);
  } catch (IOException e) {
    	e.printStackTrace();
  } catch (GeneralSecurityException e) {
      e.printStackTrace();
  }