Хеширование паролей в приложении Java

Question

У меня есть приложение для Android, написанное на Java, которое использует базу данных SQLite. Я хочу, чтобы пароли вводились на странице регистрации, чтобы генерировать хеш MD5 или SHA1, который хранится в базе данных. Который может быть использован при входе в приложение.

Может ли кто-нибудь помочь?

Регистрация

package com.example.oliver.beckettreg; 

import android.app.Activity; 
import android.content.Intent; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.EditText; 
import android.widget.Toast; 

public class SignUp extends Activity { 

DatabaseHelper helper = new DatabaseHelper(this); 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.signup); 
} 

//if button clicked 
public void onSignUpClick(View v) { 
    if (v.getId() == R.id.Bsignupbutton) { 


     EditText name = (EditText) findViewById(R.id.TFname); 
     EditText email = (EditText) findViewById(R.id.TFemail); 
     EditText uname = (EditText) findViewById(R.id.TFuname); 
     EditText pass1 = (EditText) findViewById(R.id.TFpass1); 
     EditText pass2 = (EditText) findViewById(R.id.TFpass2); 


     String namestr = name.getText().toString(); 
     String emailstr = email.getText().toString(); 
     String unamestr = uname.getText().toString(); 
     String pass1str = pass1.getText().toString(); 
     String pass2str = pass2.getText().toString(); 

     //check passwords match 
     if(!pass1str.equals(pass2str)) 


     { 
      //popup msg if fails 
      Toast pass = Toast.makeText(SignUp.this , "Passwords don't match!" , Toast.LENGTH_SHORT); 
      pass.show(); 


     } 
     else 
     { 

      //validations for data input 
      if (name.getText().toString().length() == 0) 
      {name.setError("Name Required");} 

      else if (!email.getText().toString().matches("[a-z]{1}\\.[a-z]*[0-9]{4}@student\\.leedsbeckett\\.ac\\.uk")) 
      {email.setError("Incorrect Email Format");} 

      else if (!uname.getText().toString().matches("[cC][0-9]{7}")) 
      {uname.setError("Incorrect ID Format");} 

      else if (!pass1.getText().toString().matches("(?=.*[\\d])(?=.*[a-z])(?=.*[A-Z]).{8,}")) 
      {pass1.setError("Incorrect Password Format");} 

      else{ 
       //insert the details in database 
       Contact c = new Contact(); 
       c.setName(namestr); 
       c.setEmail(emailstr); 
       c.setUname(unamestr); 
       c.setPass(pass1str); 

       helper.insertContact(c); 


       //popup if data passes validations 
       Toast pass = Toast.makeText(SignUp.this , "User Registered" , Toast.LENGTH_LONG); 
       pass.show(); 

      } 

     } 

    } 


} 


public void onButtonClick(View v) { 

    if (v.getId() == R.id.Blogin2) { 
     Intent i = new Intent(SignUp.this, com.example.oliver.beckettreg.MainActivity.class); 
     startActivity(i); 

    } 




} 
} 

Войти

package com.example.oliver.beckettreg; 

import android.support.v7.app.ActionBarActivity; 
import android.os.Bundle; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.view.View 
import android.content.Intent; 
import android.widget.EditText; 
import android.widget.Toast; 


public class MainActivity extends ActionBarActivity { 

DatabaseHelper helper = new DatabaseHelper(this); 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
} 


@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.menu_main, menu); 
    return true; 
} 

public void onButtonClick(View v) 
{ 

    //if button clicked 
    if(v.getId() == R.id.Blogin) 
    { 

     //check if passwords match 
     EditText a = (EditText)findViewById(R.id.TFusername); 
     String str = a.getText().toString(); 
     EditText b = (EditText)findViewById(R.id.TFpassword); 
     String pass = b.getText().toString(); 

     String password = helper.searchPass(str); 
     if(pass.equals(password)) 
     { 
      Intent i = new Intent(MainActivity.this, NFC.class); 
      i.putExtra("Username",str); 
      startActivity(i); 
     } 
     else 
     {å 
      Toast temp = Toast.makeText(MainActivity.this , "Username and password don't match!" , Toast.LENGTH_SHORT); 
      temp.show(); 
     } 



    } 
    //sign up button if data passes 
    if(v.getId() == R.id.Bsignup) 
    { 
     Intent i = new Intent(MainActivity.this, com.example.oliver.beckettreg.SignUp.class); 
     startActivity(i); 

    } 

    if(v.getId() == R.id.Bnfc) 
    { 
     Intent i = new Intent(MainActivity.this, com.example.oliver.beckettreg.AttendanceRegistration.class); 
     startActivity(i); 

    } 


} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    // Handle action bar item clicks here. The action bar will 
    // automatically handle clicks on the Home/Up button, so long 
    // as you specify a parent activity in AndroidManifest.xml. 
    int id = item.getItemId(); 

    //noinspection SimplifiableIfStatement 
    if (id == R.id.action_settings) { 
     return true; 
    } 

    return super.onOptionsItemSelected(item); 
} 

}

Database Helper

import android.content.ContentValues; 
import android.content.Context; 
import android.database.Cursor; 
import android.database.sqlite.SQLiteDatabase; 
import android.database.sqlite.SQLiteOpenHelper; 
import android.provider.ContactsContract; 



public class 
    DatabaseHelper extends SQLiteOpenHelper { 

//Database Version 
private static final int DATABASE_VERSION = 1; 

//Database Name 
private static final String DATABASE_NAME = "contacts.db"; 

//Table Names 
private static final String REGISTER_TABLE_NAME = "register"; 
private static final String CONTACTS_TABLE_NAME = "contacts"; 

//Contacts Column Names 
private static final String CONTACTS_COLUMN_ID = "id"; 
private static final String CONTACTS_COLUMN_NAME = "name"; 
private static final String CONTACTS_COLUMN_EMAIL = "email"; 
private static final String CONTACTS_COLUMN_UNAME = "uname"; 
private static final String CONTACTS_COLUMN_PASS = "pass"; 

//Register Column Names 
private static final String REGISTER_COLUMN_ID = "id"; 
private static final String REGISTER_COLUMN_SEMINAR = "seminar"; 
private static final String REGISTER_COLUMN_LECTURE = "lecture"; 

SQLiteDatabase db; 

//Table Create Statements 
private static final String CONTACTS_TABLE_CREATE = "create table contacts (id         integer primary key not null , " + 
    "name text not null , email text not null , uname text not null , pass text not null);"; 

private static final String REGISTER_TABLE_CREATE = "create table register   (id integer primary key not null , " + 
    " time DATETIME DEFAULT CURRENT_TIMESTAMP, seminar text not null , lecture text not null, );"; 

public DatabaseHelper(Context context) { 
super(context, DATABASE_NAME, null, DATABASE_VERSION); 
} 

//Creating Required Tables 
@Override 
public void onCreate(SQLiteDatabase db) { 
db.execSQL(REGISTER_TABLE_CREATE); 
db.execSQL(CONTACTS_TABLE_CREATE); 
this.db = db; 
} 

public void insertContact(Contact c) { 
db = this.getWritableDatabase(); 
ContentValues values = new ContentValues(); 

String query = "select * from contacts"; 
Cursor cursor = db.rawQuery(query , null); 
int count = cursor.getCount(); 

values.put(CONTACTS_COLUMN_ID, count); 
values.put(CONTACTS_COLUMN_NAME, c.getName()); 
values.put(CONTACTS_COLUMN_EMAIL, c.getEmail()); 
values.put(CONTACTS_COLUMN_UNAME, c.getUname()); 
values.put(CONTACTS_COLUMN_PASS, c.getPass()); 

db.insert(CONTACTS_TABLE_NAME, null, values); 
db.close(); 


} 

public void insertRegister(Register r) { 
db = this.getWritableDatabase(); 
ContentValues values = new ContentValues(); 

String query = "select * from register"; 
Cursor cursor = db.rawQuery(query, null); 
int count = cursor.getCount(); 

values.put(REGISTER_COLUMN_ID, count); 
values.put(REGISTER_COLUMN_SEMINAR, r.getSeminar()); 
values.put(REGISTER_COLUMN_LECTURE, r.getLecture()); 

db.insert(REGISTER_TABLE_NAME, null, values); 
db.close(); 

} 


public String searchPass(String uname) 
{ 
db = this.getReadableDatabase(); 
String query = "select uname, pass from "+CONTACTS_TABLE_NAME; 
Cursor cursor = db.rawQuery(query , null); 
String a, b; 
b = "not found"; 
if(cursor.moveToFirst()) 
{ 
    do{ 
     a = cursor.getString(0); 

     if(a.equals(uname)) 
     { 
      b = cursor.getString(1); 
      break; 
     } 
    } 
    while(cursor.moveToNext()); 
    } 

return b; 
} 


    //On Upgrade Drop Older Tables 
@Override 
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
    db.execSQL("DROP TABLE IF EXISTS " + REGISTER_TABLE_NAME); 
db.execSQL("DROP TABLE IF EXISTS " + CONTACTS_TABLE_NAME); 

//Create New Tables 
this.onCreate(db); 

} 

} 

Answer 1

Вы можете реализовать этот метод, который будет возвращать хэш в виде строки.

private String hashMe(String password) { 

    try { 
     MessageDigest md = MessageDigest.getInstance("SHA-1"); //could also be MD5, SHA-256 etc. 
     md.reset(); 
     md.update(password.getBytes("UTF-8")); 
     byte[] resultByte = md.digest(); 
     password = String.format("%01x", new java.math.BigInteger(1, resultByte)); 

    } catch (NoSuchAlgorithmException e) { 
     //do something. 
    } catch (UnsupportedEncodingException ex) { 
     //do something 
    } 
    return password; 
} 

Поскольку вы имеете дело с паролями, вы должны также соль хэша, и сохранить их как в вашем Дб.