Password asking

[Kruptein]

I want to ask a password before someone uses my program
a) is this safe
b) is it possible to use more then one password

I currently have:

private static boolean CheckPswd(char[] pswd) {
        boolean isCorrect = true;
        char[] correctPassword = { 'P', 'a', 's', 's', 'w', 'o', 'r', 'd' };
        if (pswd.length != correctPassword.length) {
            isCorrect = false;
        } else {
            isCorrect = Arrays.equals (pswd, correctPassword);
        }

        //Zero out the password.
        Arrays.fill(correctPassword,'0');
        return isCorrect;
    }

[Kruptein]

Alright,
I had to ask this immediatly,
so: How can you make use of more passwords?

And wich hashes are avaible for java?
md5, sha1, DES, ???

[emceenugget]

you can use an array or any kidn of container to hold whatever object you have for a password (char array, string...)

[emceenugget]

you can use md5 or sha-1 for hashes. just look up the 'messagedigest' class and it should link you to a bunch of info you need, including valid encryption algorithms. i haven't used this stuff in over a year and even when i did i barely touched on it, but it isnt TOO complicated... i think

[Kruptein]

I tried this:

private static boolean CheckPswd(char[] pswd) {
        boolean isCorrect = true;
        char[] p1 = {'P', 'a', 's', 's', 'w', 'o', 'r', 'd'};
        char[] p2 = {'P', 'a', 's', 's', 'w', 'o', 'r', 'e'};
        char[] pass = {p1,p2};
        for(int i=0; i<pass.length; i++){
            if (pswd.length != pass.length) {
                isCorrect = false;
            } else {
                isCorrect = Arrays.equals (pswd, pass[i]);
            }
        }

        //Zero out the password.
        Arrays.fill(pass,'0');
        return isCorrect;
    }

}

But this doesn't work,
where have I done something wrong?

[Singing Boyo]

char[] pass = {p1,p2}
should be
char[][] pass = {p1,p2}

And you really should encrypt your password, if the data is sensitive... You might even want to encrypt, in some way, high-sensitivity data in general.

[Kruptein]

Yes ofcourse I should encrypt it, but I have to be sure it works first,

it gives me this error:

Exception in thread "AWT-EventQueue-0" java.lang.ArrayStoreException: java.lang.Character
at java.util.Arrays.fill(Arrays.java:2710)
at java.util.Arrays.fill(Arrays.java:2685)
at D_Programs.D_MENU.CheckPswd(D_MENU.java:450)
at D_Programs.D_MENU.LoginButtonActionPerformed(D_MEN U.java:230)
at D_Programs.D_MENU.access$000(D_MENU.java:33)
at D_Programs.D_MENU$1.actionPerformed(D_MENU.java:78 )
at javax.swing.AbstractButton.fireActionPerformed(Abs tractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed (AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed (DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultB uttonModel.java:242)
at javax.swing.plaf.basic.BasicButtonListener.mouseRe leased(BasicButtonListener.java:236)
at java.awt.Component.processMouseEvent(Component.jav a:6263)
at javax.swing.JComponent.processMouseEvent(JComponen t.java:3267)
at java.awt.Component.processEvent(Component.java:602 8)
at java.awt.Container.processEvent(Container.java:204 1)
at java.awt.Component.dispatchEventImpl(Component.jav a:4630)
at java.awt.Container.dispatchEventImpl(Container.jav a:2099)
at java.awt.Component.dispatchEvent(Component.java:44 60)
at java.awt.LightweightDispatcher.retargetMouseEvent( Container.java:4574)
at java.awt.LightweightDispatcher.processMouseEvent(C ontainer.java:4238)
at java.awt.LightweightDispatcher.dispatchEvent(Conta iner.java:4168)
at java.awt.Container.dispatchEventImpl(Container.jav a:2085)
at java.awt.Window.dispatchEventImpl(Window.java:2475 )
at java.awt.Component.dispatchEvent(Component.java:44 60)
at java.awt.EventQueue.dispatchEvent(EventQueue.java: 599)
at java.awt.EventDispatchThread.pumpOneEventForFilter s(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(E ventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarch y(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThre ad.java:122)
Exception in thread "AWT-EventQueue-0" java.lang.ArrayStoreException: java.lang.Character
at java.util.Arrays.fill(Arrays.java:2710)
at java.util.Arrays.fill(Arrays.java:2685)
at D_Programs.D_MENU.CheckPswd(D_MENU.java:450)
at D_Programs.D_MENU.LoginButtonActionPerformed(D_MEN U.java:230)
at D_Programs.D_MENU.access$000(D_MENU.java:33)
at D_Programs.D_MENU$1.actionPerformed(D_MENU.java:78 )
at javax.swing.AbstractButton.fireActionPerformed(Abs tractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed (AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed (DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultB uttonModel.java:242)
at javax.swing.plaf.basic.BasicButtonListener.mouseRe leased(BasicButtonListener.java:236)
at java.awt.Component.processMouseEvent(Component.jav a:6263)
at javax.swing.JComponent.processMouseEvent(JComponen t.java:3267)
at java.awt.Component.processEvent(Component.java:602 8)
at java.awt.Container.processEvent(Container.java:204 1)
at java.awt.Component.dispatchEventImpl(Component.jav a:4630)
at java.awt.Container.dispatchEventImpl(Container.jav a:2099)
at java.awt.Component.dispatchEvent(Component.java:44 60)
at java.awt.LightweightDispatcher.retargetMouseEvent( Container.java:4574)
at java.awt.LightweightDispatcher.processMouseEvent(C ontainer.java:4238)
at java.awt.LightweightDispatcher.dispatchEvent(Conta iner.java:4168)
at java.awt.Container.dispatchEventImpl(Container.jav a:2085)
at java.awt.Window.dispatchEventImpl(Window.java:2475 )
at java.awt.Component.dispatchEvent(Component.java:44 60)
at java.awt.EventQueue.dispatchEvent(EventQueue.java: 599)
at java.awt.EventDispatchThread.pumpOneEventForFilter s(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(E ventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarch y(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThre ad.java:122)
Exception in thread "AWT-EventQueue-0" java.lang.ArrayStoreException: java.lang.Character
at java.util.Arrays.fill(Arrays.java:2710)
at java.util.Arrays.fill(Arrays.java:2685)
at D_Programs.D_MENU.CheckPswd(D_MENU.java:450)
at D_Programs.D_MENU.LoginButtonActionPerformed(D_MEN U.java:230)
at D_Programs.D_MENU.access$000(D_MENU.java:33)
at D_Programs.D_MENU$1.actionPerformed(D_MENU.java:78 )
at javax.swing.AbstractButton.fireActionPerformed(Abs tractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed (AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed (DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultB uttonModel.java:242)
at javax.swing.plaf.basic.BasicButtonListener.mouseRe leased(BasicButtonListener.java:236)
at java.awt.Component.processMouseEvent(Component.jav a:6263)
at javax.swing.JComponent.processMouseEvent(JComponen t.java:3267)
at java.awt.Component.processEvent(Component.java:602 8)
at java.awt.Container.processEvent(Container.java:204 1)
at java.awt.Component.dispatchEventImpl(Component.jav a:4630)
at java.awt.Container.dispatchEventImpl(Container.jav a:2099)
at java.awt.Component.dispatchEvent(Component.java:44 60)
at java.awt.LightweightDispatcher.retargetMouseEvent( Container.java:4574)
at java.awt.LightweightDispatcher.processMouseEvent(C ontainer.java:4238)
at java.awt.LightweightDispatcher.dispatchEvent(Conta iner.java:4168)
at java.awt.Container.dispatchEventImpl(Container.jav a:2085)
at java.awt.Window.dispatchEventImpl(Window.java:2475 )
at java.awt.Component.dispatchEvent(Component.java:44 60)
at java.awt.EventQueue.dispatchEvent(EventQueue.java: 599)
at java.awt.EventDispatchThread.pumpOneEventForFilter s(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(E ventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarch y(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThre ad.java:122)
BUILD STOPPED (total time: 31 seconds)

private static boolean CheckPswd(char[] pswd) {
        boolean isCorrect = true;
        char[] p1 = {'P', 'a', 's', 's', 'w', 'o', 'r', 'd'};
        char[] p2 = {'P', 'a', 's', 's', 'w', 'o', 'r', 'e'};
        char[][] pass = {p1,p2};
        for(int i=0; i<pass.length; i++){
            if (pswd.length != pass.length) {
                isCorrect = false;
            } else {
                isCorrect = Arrays.equals (pswd, pass[i]);
            }
        }

        //Zero out the password.
        Arrays.fill(pass,'0');
        return isCorrect;
    }

[Singing Boyo]

replace Arrays.fill(pass, 0) with

for(int i=0; i<pass.length; i++){
     Arrays.fill(pass[i],'0');
}

you cant fill an array of character arrays with '0', you have to fill each individual character array. pass is an array of character arrays, pass[index] is a character array.

[Kruptein]

It now just always says: Login failed,

private static boolean CheckPswd(char[] pswd) {
        boolean isCorrect = true;
        char[] p1 = {'P', 'a', 's', 's', 'w', 'o', 'r', 'd'};
        char[] p2 = {'P', 'a', 's', 's', 'w', 'o', 'r', 'e'};
        char[][] pass = {p1,p2};
        for(int i=0; i<pass.length; i++){
            if (pswd.length != pass.length) {
                isCorrect = false;
            } else {
                isCorrect = Arrays.equals (pswd, pass[i]);
            }
            //Zero out the password.
            Arrays.fill(pass[i],'0');
        }
        return isCorrect;
    }

[dlorde]

It will always return false because the password can't match both p1 and p2...

If you're trying to test for a match against one of the hard-coded passwords, exit the loop when you find one that matches for length and content.

[Kruptein]

EDIT: Solved

[Kruptein]

Okay I've solved it with a while-loop,

private static boolean CheckPswd(char[] pswd) {
        boolean isCorrect = true;
        char[] p1 = {'P', 'a', 's', 's', 'w', 'o', 'r', 'd'};
        char[] p2 = {'P', 'a', 's', 's', 'w', 'o', 'r', 'e'};
        char[][] pass = {p1,p2};
        int i = 1;
        while(!isCorrect){
            if(pswd.length != pass.length) {
                isCorrect = false;
            }else{
                isCorrect = Arrays.equals(pswd, pass[i]);
            }
            Arrays.fill(pass[i],'0');
            i++;
        }
        return isCorrect;
    }

[Kruptein]

The while loop always returns login successfull ...
:( why?

[Fubarable]

Does your while loop ever get entered?

[Kruptein]

Okay your right, now the while loop is entered, but now always returns LOGIN FAIL

private static boolean CheckPswd(char[] pswd) throws NoSuchAlgorithmException {
        boolean isCorrect = true;
        char[] p1 = {'P', 'a', 's', 's', 'w', 'o', 'r', 'd'};
        char[] p2 = {'P', 'a', 's', 's', 'w', 'o', 'r', 'e'};
        char[][] pass = {p1,p2};
        int i = 1;
        isCorrect = false;
        while(i>pass.length){
            while(!isCorrect){
                if(pswd.length != pass.length) {
                    isCorrect = false;
                }else{
                    isCorrect = Arrays.equals(pswd, pass[i]);
                }
            }
            i++;
        }
        Arrays.fill(pass[0],'0');
        Arrays.fill(pass[1],'0');
        return isCorrect;

ofcourse this is easier to do with a for loop, (the one I had first), but why does it return Login Fail?

[Fubarable]

1) Do you want to compare password lengths within the loop.
2) Working this out will require a bit of thought and a lot of paper. Try walking through your code logic as if you were the JVM and work through a few examples walking through your code step-by-step to see where your fallacies lie. This exercise will help you in the long run.

[dlorde]

... why does it return Login Fail?

If you step through it, you'll see you set i = 1, followed by the loop condition 'while(i>pass.length)'...

I suggest you start again on that loop - what you've got there is a mess. I did suggest a way to to it previously - and you're still welcome to use it.

As Fubarable says, you need to work out on paper, step by step, exactly how this code will work - in English, before translating it into Java code.

[Kruptein]

Okay,

-User clicks on login-button
-Content of password field is sent to the script
-Content goes trough messagedigest.
-the crypted content has to be the same as an other hashed string
-if they are the same, show login successfull

something like this?

[Fubarable]

No. Walk through your loops step by step.

[Kruptein]

Okay,

-run password trough messagedigest = hashed input
-if hashed input is the same as first possible pass: login successfull
-else if hashed input is the same as second possible pass: login successfull
-else if hashed input is not the same as a possible pass: login failed

this?