C# Random Password Generator

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In an earlier post, I wrote a Random Password Generator class intended for anyone interested to plug into their application.

Following some input I received, I have refactored the code a bit:

using System;
using System.Security.Cryptography;


namespace Security
{

    public class RandomPasswordGenerator
    {
        // Define default password length.
        private static int DEFAULT_PASSWORD_LENGTH = 8;

        //No characters that are confusing: i, I, l, L, o, O, 0, 1, u, v

        public static string PASSWORD_CHARS_ALPHA = 
                                "abcdefghjkmnpqrstwxyzABCDEFGHJKMNPQRSTWXYZ";
        public static string PASSWORD_CHARS_NUMERIC = "23456789";
        public static string PASSWORD_CHARS_SPECIAL = "*$-+?_&=!%{}/";
        public static string PASSWORD_CHARS_ALPHANUMERIC = 
                                PASSWORD_CHARS_ALPHA + PASSWORD_CHARS_NUMERIC;
        public static string PASSWORD_CHARS_ALL = 
                                PASSWORD_CHARS_ALPHANUMERIC + PASSWORD_CHARS_SPECIAL;
        
        //These overloads are only necesary in versions of .NET below 4.0
        #region Overloads

        /// 

        /// Generates a random password with the default length.
        /// 
        /// Randomly generated password.
        public static string Generate()
        {
            return Generate(DEFAULT_PASSWORD_LENGTH,
                            PASSWORD_CHARS_ALL);
        }

        /// 

        /// Generates a random password with the default length.
        /// 
        /// Randomly generated password.
        public static string Generate(string passwordChars)
        {
            return Generate(DEFAULT_PASSWORD_LENGTH, 
                            passwordChars);
        }

        /// 

        /// Generates a random password with the default length.
        /// 
        /// Randomly generated password.
        public static string Generate(int passwordLength)
        {
            return Generate(passwordLength,
                            PASSWORD_CHARS_ALL);
        }

        /// 

        /// Generates a random password.
        /// 
        /// Randomly generated password.
        public static string Generate(int passwordLength,
                                      string passwordChars)
        {
            return GeneratePassword(passwordLength, 
                                    passwordChars);
        }

        #endregion


        /// 

        /// Generates the password.
        /// 
        /// 
        private static string GeneratePassword(int passwordLength,
                                               string passwordCharacters)
        {
            if (passwordLength < 0) 
                throw new ArgumentOutOfRangeException("Password Length");

            if (string.IsNullOrEmpty(passwordCharacters)) 
                throw new ArgumentOutOfRangeException("Password Characters");
            
            var password = new char[passwordLength];

            var random = GetRandom();

            for (int i = 0; i < passwordLength; i++)
                password[i] = passwordCharacters[
                                          random.Next(passwordCharacters.Length)];

            return new string(password);
        }



        

        /// 

        /// Gets a random object with a real random seed
        /// 
        /// 
        private static Random GetRandom()
        {
            // Use a 4-byte array to fill it with random bytes and convert it then
            // to an integer value.
            byte[] randomBytes = new byte[4];

            // Generate 4 random bytes.
            new RNGCryptoServiceProvider().GetBytes(randomBytes);

            // Convert 4 bytes into a 32-bit integer value.
            int seed = (randomBytes[0] & 0x7f) << 24 |
                        randomBytes[1] << 16 |
                        randomBytes[2] << 8 |
                        randomBytes[3];

            // Now, this is real randomization.
            return new Random(seed);
        }


    }
}

What are TFS Labels for?

Just some interesting reading in the following links:

http://iworkonsoftware.blogspot.com/2010/04/tfs-labels.html

http://www.notionsolutions.com/notionmedia/articles/Pages/VirtuesandPitfallsoftheTFSLabel.aspx

How do you use TFS Labels?

C# ASP.NET CheckBoxList selecting items on OnDataBinding doesn't work, set it on OnDataBound instead

When I try to bind some objects to a CheckBoxList in the OnDataBinding method, it never seems to select it when I tell it to do so:

protected override void OnDataBinding(EventArgs e)
 {
    base.OnDataBinding(e);
 
    chkBxLstProducts.DataSource = Product.GetAll();
    chkBxLstProducts.DataBind();
 
    foreach (var item in chkBxLstProducts.Items.Cast())
    {
         item.Selected = ((ICollection)FieldValue).Cast()
                         .Any(p => p.ProductId == Convert.ToInt32(item.Value));
    }
 }

 

When I move the selection code into the OnDataBound method, it works:

protected override void OnDataBinding(EventArgs e)
 {
    base.OnDataBinding(e);
    
    chkBxLstProducts.DataSource = Product.GetAll();
    chkBxLstProducts.DataBind();
 }

 protected void OnDataBound(object sender, EventArgs e)
 {
    foreach (var item in chkBxLstProducts.Items.Cast())
    {
        item.Selected = ((ICollection)FieldValue).Cast()
                        .Any(p => p.ProductId == Convert.ToInt32(item.Value));
    }
 }

I’m not 100% sure, but I think it’s because the OnDataBinding event occurs before the CheckBoxList is rendered. So after it’s rendered, everything is wiped clean and we lose the selection. Selecting items after OnDataBound ensures it gets rendered.

C# Random Password Generator

Below is a class for you to plug into your projects.

It generates random passwords by using actual random seed and omits those pesky letters that look similar to one another.

You can reuse the class by passing in options such as password length and the different characters you want to include. And since its the source code, you can extend/adapt it to your needs.

Enjoy

This blog post has moved to my new blog, you are about to be redirected...

using System;
using System.Security.Cryptography;
 
 
namespace Security
{
    public enum RandomPasswordOptions
    {
        Alpha = 1,
        Numeric = 2,
        AlphaNumeric = Alpha + Numeric,
        AlphaNumericSpecial = 4
    }
 
    public class RandomPasswordGenerator
    {
        // Define default password length.
        private static int DEFAULT_PASSWORD_LENGTH = 8;
 
        //No characters that are confusing: i, I, l, L, o, O, 0, 1, u, v
 
        private static string PASSWORD_CHARS_Alpha = 
                                   "abcdefghjkmnpqrstwxyzABCDEFGHJKMNPQRSTWXYZ";
        private static string PASSWORD_CHARS_NUMERIC = "23456789";
        private static string PASSWORD_CHARS_SPECIAL = "*$-+?_&=!%{}/";
 
        #region Overloads
 
        /// 

        /// Generates a random password with the default length.
        /// 
        /// Randomly generated password.
        public static string Generate()
        {
            return Generate(DEFAULT_PASSWORD_LENGTH, 
                            RandomPasswordOptions.AlphaNumericSpecial);
        }
 
        /// 

        /// Generates a random password with the default length.
        /// 
        /// Randomly generated password.
        public static string Generate(RandomPasswordOptions option)
        {
            return Generate(DEFAULT_PASSWORD_LENGTH, option);
        }
 
        /// 

        /// Generates a random password with the default length.
        /// 
        /// Randomly generated password.
        public static string Generate(int passwordLength)
        {
            return Generate(DEFAULT_PASSWORD_LENGTH, 
                            RandomPasswordOptions.AlphaNumericSpecial);
        }
 
        /// 

        /// Generates a random password.
        /// 
        /// Randomly generated password.
        public static string Generate(int passwordLength, 
                                      RandomPasswordOptions option)
        {
            return GeneratePassword(passwordLength, option);
        }
 
        #endregion
 
 
        /// 

        /// Generates the password.
        /// 
        /// 
        private static string GeneratePassword(int passwordLength, 
                                               RandomPasswordOptions option)
        {
            if (passwordLength < 0) return null;
 
            var passwordChars = GetCharacters(option);
 
            if (string.IsNullOrEmpty(passwordChars)) return null;
 
            var password = new char[passwordLength];
 
            var random = GetRandom();
 
            for (int i = 0; i < passwordLength; i++)
            {
                var index = random.Next(passwordChars.Length);
                var passwordChar = passwordChars[index];
 
                password[i] = passwordChar;
            }
 
            return new string(password);
        }
 
 
 
        /// 

        /// Gets the characters selected by the option
        /// 
        /// 
        private static string GetCharacters(RandomPasswordOptions option)
        {
            switch (option)
            {
                case RandomPasswordOptions.Alpha:
                    return PASSWORD_CHARS_Alpha;
                case RandomPasswordOptions.Numeric:
                    return PASSWORD_CHARS_NUMERIC;
                case RandomPasswordOptions.AlphaNumeric:
                    return PASSWORD_CHARS_Alpha + PASSWORD_CHARS_NUMERIC;
                case RandomPasswordOptions.AlphaNumericSpecial:
                    return PASSWORD_CHARS_Alpha + PASSWORD_CHARS_NUMERIC + 
                                 PASSWORD_CHARS_SPECIAL;
                default:
                    break;
            }
            return string.Empty;
        }
        
        /// 

        /// Gets a random object with a real random seed
        /// 
        /// 
        private static Random GetRandom()
        {
            // Use a 4-byte array to fill it with random bytes and convert it then
            // to an integer value.
            byte[] randomBytes = new byte[4];
 
            // Generate 4 random bytes.
            RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider();
            rng.GetBytes(randomBytes);
 
            // Convert 4 bytes into a 32-bit integer value.
            int seed = (randomBytes[0] & 0x7f) << 24 |
                        randomBytes[1] << 16 |
                        randomBytes[2] << 8 |
                        randomBytes[3];
 
            // Now, this is real randomization.
            return new Random(seed);
        }
 
 
    }
}

Priorities

God doesn't demand I accomplish great things, He demands I strive for excellent relationships.

He doesn't care that I create great Software, but achieve great relationships.

Browser Testing in IE 5,6,7,8

I found a neat little tool for doing browser testing on all the IE browsers.

http://www.my-debugbar.com/wiki/IETester/HomePage

You can easily open sites in each of the browsers in individual tabs. I needed to use this after trying out the IE Collection and my computer wouldn't run it because of some malware. compatibility

CSS Gradient that works cross browsers

Found this site very interesting.

http://www.webdesignerwall.com/tutorials/cross-browser-css-gradient/