/*
 * This file was generated by ProCG version 2.0
 *
 * File name:	Northwind\General\PasswordGenerator.cs
 * Language:	C# - ADO.Net 
 * Database:	My Sql
 *
 * Copyright (c) 2002-2019 iGenXSoft.
 * For more information visit http://www.igenxsoft.com
 */


using System;
using System.Collections.Generic;
using System.Security.Cryptography;
using System.Text;

namespace Northwind.General
{
	public class PasswordGenerator
	{
		public PasswordGenerator()
		{
			this.Minimum = DefaultMinimum;
			this.Maximum = DefaultMaximum;
			this.ConsecutiveCharacters = false;
			this.RepeatCharacters = true;
			this.ExcludeSymbols = true;
			this.Exclusions = null;

			rng = new RNGCryptoServiceProvider();
		}

		protected int GetCryptographicRandomNumber(int lBound, int uBound)
		{
			// Assumes lBound >= 0 && lBound < uBound
			// returns an int >= lBound and < uBound
			uint urndnum;
			byte[] rndnum = new Byte[4];
			if (lBound == uBound - 1)
			{
				// test for degenerate case where only lBound can be returned   
				return lBound;
			}

			uint xcludeRndBase = (uint.MaxValue - (uint.MaxValue % (uint)(uBound - lBound)));

			do
			{
				rng.GetBytes(rndnum);
				urndnum = System.BitConverter.ToUInt32(rndnum, 0);
			} while (urndnum >= xcludeRndBase);

			return (int)(urndnum % (uBound - lBound)) + lBound;
		}

		protected char GetRandomCharacter()
		{
			int upperBound = pwdCharArray.GetUpperBound(0);

			if (true == this.ExcludeSymbols)
			{
				upperBound = PasswordGenerator.UBoundDigit;
			}

			int randomCharPosition = GetCryptographicRandomNumber(pwdCharArray.GetLowerBound(0), upperBound);

			char randomChar = pwdCharArray[randomCharPosition];

			return randomChar;
		}

		public string Generate()
		{
			// Pick random length between minimum and maximum   
			int pwdLength = GetCryptographicRandomNumber(this.Minimum, this.Maximum);

			StringBuilder pwdBuffer = new StringBuilder();
			pwdBuffer.Capacity = this.Maximum;

			// Generate random characters
			char lastCharacter, nextCharacter;

			// Initial dummy character flag
			lastCharacter = nextCharacter = '\n';

			for (int i = 0; i < pwdLength; i++)
			{
				nextCharacter = GetRandomCharacter();

				if (false == this.ConsecutiveCharacters)
				{
					while (lastCharacter == nextCharacter)
					{
						nextCharacter = GetRandomCharacter();
					}
				}

				if (false == this.RepeatCharacters)
				{
					string temp = pwdBuffer.ToString();
					int duplicateIndex = temp.IndexOf(nextCharacter);
					while (-1 != duplicateIndex)
					{
						nextCharacter = GetRandomCharacter();
						duplicateIndex = temp.IndexOf(nextCharacter);
					}
				}

				if ((null != this.Exclusions))
				{
					while (-1 != this.Exclusions.IndexOf(nextCharacter))
					{
						nextCharacter = GetRandomCharacter();
					}
				}

				pwdBuffer.Append(nextCharacter);
				lastCharacter = nextCharacter;
			}

			if (null != pwdBuffer)
			{
				return pwdBuffer.ToString();
			}
			else
			{
				return String.Empty;
			}
		}

		public string Exclusions
		{
			get { return this.exclusionSet; }
			set { this.exclusionSet = value; }
		}

		public int Minimum
		{
			get { return this.minSize; }
			set
			{
				this.minSize = value;
			}
		}

		public int Maximum
		{
			get { return this.maxSize; }
			set
			{
				this.maxSize = value;
			}
		}

		public bool ExcludeSymbols
		{
			get { return this.hasSymbols; }
			set { this.hasSymbols = value; }
		}

		public bool RepeatCharacters
		{
			get { return this.hasRepeating; }
			set { this.hasRepeating = value; }
		}

		public bool ConsecutiveCharacters
		{
			get { return this.hasConsecutive; }
			set { this.hasConsecutive = value; }
		}

		private const int DefaultMinimum = 7;
		private const int DefaultMaximum = 10;
		private const int UBoundDigit = 61;

		private RNGCryptoServiceProvider rng;
		private int minSize;
		private int maxSize;
		private bool hasRepeating;
		private bool hasConsecutive;
		private bool hasSymbols;
		private string exclusionSet;
		private char[] pwdCharArray = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789`~!@#$%^&*()-_=+[]{}\\|;:'\",<.>/?".ToCharArray();
		//private char[] pwdCharArray = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789".ToCharArray();
	}
}


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