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Simple Password Generator

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18 Dec 2013CPOL 31K   27   9
Simple password generator, based on alphabets

Introduction 

Sometimes you need to create words from a given alphabet, so I'd like to share a very simple solution. The solution is scalable, so you can add your own alphabet. Let's take a look at the code.

Using the Code

The code consists of several classes:

  • AlphabetDictionaries - predefined alphabets
  • AlphabetWordGenerator - generate word accordingly alphabet

C#
public static class AlphabetDictionaries
{
    public const string EnglishLowerCase = "abcdefghijklmnopqrstuvwxyz";
    public const string EnglishUpperCase = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    public const string Numeric = "0123456789";
    public const string SpecialSymbols = "`~!@#$%^&*()-_=+[]{}\\|;:'\",<.>/?";
}   

Here's main and only one class - AlphabetWordGenerator

C#
public sealed class AlphabetWordGenerator : IWordGenerator
{
    private readonly string _alphabet;
    private readonly RNGCryptoServiceProvider _provider = new RNGCryptoServiceProvider();

    public AlphabetWordGenerator(ICollection<string> alphabets)
    {
        if (alphabets == null || alphabets.Count == 0)
        {
            throw new ArgumentException("Alphabets is null or empty");
        }
        if (alphabets.Any(string.IsNullOrWhiteSpace))
        {
            throw new ArgumentException("Alphabet should not be ampty");
        }
        _alphabet = string.Join(string.Empty, alphabets);
    }

    public AlphabetWordGenerator(string alphabet)
        : this(new[] { alphabet })
    {
    }

    public string Generate(int wordLength)
    {
        if (wordLength < 1)
        {
            throw new IndexOutOfRangeException("wordLength is out of range");
        }
        return DoGenerate(wordLength);
    }

    private string DoGenerate(int wordLength)
    {
        var repository = new List<char>(wordLength);
        var data = new byte[wordLength];
        _provider.GetBytes(data);
        foreach (byte item in data)
        {
            int index = Convert.ToInt32(item)%_alphabet.Length;
            char symbol = _alphabet[index];
            repository.Add(symbol);
        }
        return string.Join(string.Empty, repository);
    }
} 

Let's create a word with lowercase English letters:

C#
var generator = new AlphabetWordGenerator(AlphabetDictionaries.EnglishLowerCase);
                    
var password = generator.Generate(10); 

Result password is equal to uddfxjfbxp 

Another example with several alphabets:

C#
var alphabets = new List<string>
{
    AlphabetDictionaries.EnglishLowerCase,
    AlphabetDictionaries.EnglishUpperCase,
    AlphabetDictionaries.Numeric,
    AlphabetDictionaries.SpecialSymbols,
};

var generator = new AlphabetWordGenerator(alphabets);
                    
var password = generator.Generate(40);    

Result password is equal to [3xH(kzizo@51m@q}qpIYq[CgUBbjKf^3E@JF^T;

History

  • 26th July, 2012: Initial version
  • 20th December, 2013: Length's been moved to generate method

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Software Developer (Senior)
United States United States
B.Sc. in Computer Science.

Comments and Discussions

 
SuggestionDoes what it says Pin
John Brett19-Dec-13 4:30
John Brett19-Dec-13 4:30 
GeneralRe: Does what it says Pin
Sergey Morenko20-Dec-13 9:06
professionalSergey Morenko20-Dec-13 9:06 
Question[My vote of 2] 2 Easier Way Pin
Kevin Marois26-Jul-12 7:01
professionalKevin Marois26-Jul-12 7:01 
AnswerRe: [My vote of 2] 2 Easier Way Pin
Sergey Morenko26-Jul-12 7:18
professionalSergey Morenko26-Jul-12 7:18 
GeneralRe: [My vote of 2] 2 Easier Way Pin
Kevin Marois26-Jul-12 7:27
professionalKevin Marois26-Jul-12 7:27 
GeneralRe: [My vote of 2] 2 Easier Way Pin
Sergey Morenko26-Jul-12 7:40
professionalSergey Morenko26-Jul-12 7:40 
GeneralRe: [My vote of 2] 2 Easier Way Pin
Caner Korkmaz26-Jul-12 8:33
Caner Korkmaz26-Jul-12 8:33 
GeneralMy vote of 5 Pin
zhanazhan25-Jul-12 17:50
zhanazhan25-Jul-12 17:50 
GeneralRe: My vote of 5 Pin
Sergey Morenko25-Jul-12 19:18
professionalSergey Morenko25-Jul-12 19:18 

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