java - Java 应用程序中的哈希密码

Question

我有一个用 Java 编写的 Android 应用程序，它使用 SQLite 数据库。我希望在注册页面上输入密码时生成 MD5 或 SHA1 哈希值，并将其存储在数据库中。然后可以在重新登录应用程序时使用它。

有人可以提供帮助吗？

注册

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);

    }




}
}

登录

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);
}

}

数据库助手

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

您可以实现此方法，它将以字符串形式返回哈希值。

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;
}

由于您正在处理密码，因此您还应该对哈希加盐，并将它们都保存在您的数据库中。