Spot the wrong:

[Illnab1024]

This thing does an xor encrypt on the selection from a series of sha512 hashes based on a user-input password. Works fine in codelab, screws up when compiled. I don't feel like putting it in a VS solution to make it work, and the CodeLab output source looks fine.

Error:

Full error message: PaintDotNet.WorkerThreadException: Worker thread threw an exception ---> System.NullReferenceException: Object reference not set to an instance of an object.

at PasswordProtectEffect.PasswordProtectEffectPlugin.Render(Surface dst, Surface src, Rectangle rect)

at PasswordProtectEffect.PasswordProtectEffectPlugin.OnRender(Rectangle[] rois, Int32 startIndex, Int32 length)

I can't find it.

Codelab source:

#region UICode
string Amount1 = "Password"; // Password
#endregion

void Render(Surface dst, Surface src, Rectangle rect)
{
   byte[] hashValue;
   Rectangle selection = this.EnvironmentParameters.GetSelection(src.Bounds).GetBoundsInt();
   hashValue = getArray(selection);
   byte B, G, R, A;
   long offset;
   for (int j = rect.Top; j < rect.Bottom; j++)
   {
       for (int i = rect.Left; i < rect.Right; i++)
       {
           offset = 4*(selection.Width*(j-selection.Top)+(i-selection.Left));
           B = (byte)(src[i,j].B ^ hashValue[offset]);
           G = (byte)(src[i,j].G ^ hashValue[offset+1]);
           R = (byte)(src[i,j].R ^ hashValue[offset+2]);
           A = (byte)(src[i,j].A ^ hashValue[offset+3]);
           dst[i,j] = ColorBgra.FromBgra(B, G, R, A);
       }
   }
}
private string cachedAmount1 = string.Empty;
private long arrayLength;
private byte[] cachedArray;
public byte[] getArray(Rectangle selection)
{
   if(Amount1 == cachedAmount1)
   {
       return cachedArray;
   }
   arrayLength = selection.Width*selection.Height*4;
   byte[] ourArray = new byte[arrayLength]; // TAKE THAT, MEMORY!
   byte[] b;
   long iGo = arrayLength/64;
   System.Text.Encoding enc = new System.Text.ASCIIEncoding();
   for(int i = 0; i < iGo; i++)
   {
       System.Security.Cryptography.HashAlgorithm hash = new System.Security.Cryptography.SHA512Managed();
       b = hash.ComputeHash(enc.GetBytes(Amount1+i.ToString()));
       b.CopyTo(ourArray, i*64);
   }
   cachedArray = ourArray;
   cachedAmount1 = Amount1;        
   return ourArray;
}

And getArray() is fine.

[pyrochild]

...
public byte[] getArray(Rectangle selection)
{
   if(cachedArray != null && Amount1 == cachedAmount1)
   {
       return cachedArray;
   }
...

Fixed

byte[] ourArray = new byte[arrayLength]; // TAKE THAT, MEMORY!

[Illnab1024]

Oh, right... I had thought about that halfway through before dismissing it-- CodeLab defines the default value for Amount1 in OnCreateConfigUI or whatnot as "" == string.Empty.. hooray for codelab?

[pyrochild]

Hooray for Code Lab!