Its been a while, but I plan a couple of posts.
Firstly, I was recently reminded of a .Net ‘trick’ I learnt from a friend. We recently took this trick to a new level of ‘evil’.
Strings are immutable right… well sort of.
string a = “a”;
GCHandle handle = GCHandle.Alloc(a, GCHandleType.Pinned);
char[] newString = new char[] {‘b’};
Marshal.Copy(newString, 0, handle.AddrOfPinnedObject(), 1);
Console.Out.WriteLine(a);
Console.ReadKey();
This program outputs the character b. All without actually using the unsafe keyword. The unsafe APIs already exist there to use. (They all have unmanaged permission link demand on them.)
Taking things to the next level however, allows for a bit of fun.
Examples include:
Environment.NewLine, change it to any two characters of your choice.
Exception messages, cause it once, change it and from then on it says whatever you like.
With a bit of reflection however, you can do alot of damage. For instance, change every string which can be found by walking the object hierarchy starting from static fields.