ByteArrayRocks.cs

// from http://stackoverflow.com/questions/283456/byte-array-pattern-search

using System;
using System.Collections.Generic;

static class ByteArrayRocks {

	static readonly int[] Empty = new int[0];

	public static int[] Locate( this byte[] self, byte[] candidate ) {
		if ( IsEmptyLocate( self, candidate ) )
			return Empty;

		var list = new List<int>();

		for ( int i = 0; i < self.Length; i++ ) {
			if ( !IsMatch( self, i, candidate ) )
				continue;

			list.Add( i );
		}

		return list.Count == 0 ? Empty : list.ToArray();
	}

	static bool IsMatch( byte[] array, int position, byte[] candidate ) {
		if ( candidate.Length > ( array.Length - position ) )
			return false;

		for ( int i = 0; i < candidate.Length; i++ )
			if ( array[position + i] != candidate[i] )
				return false;

		return true;
	}

	static bool IsEmptyLocate( byte[] array, byte[] candidate ) {
		return array == null
			|| candidate == null
			|| array.Length == 0
			|| candidate.Length == 0
			|| candidate.Length > array.Length;
	}
}