/// <summary>
/// Common method to generate the password for strings and <see cref="SecureString"/>s
/// </summary>
/// <typeparam name="T">The type of the password to return</typeparam>
/// <param name="length">The length of the password to generate</param>
/// <param name="allowedCharacters">Set of allowed characters in the generated password</param>
/// <param name="excludeCharacters">Set of disallowed characters in the generated password</param>
/// <param name="initialValue">Function to generate the initial password to return</param>
/// <param name="appender">Function to append a character to the password</param>
/// <returns>The generated password</returns>
private static T InternalGenerate <T>(int length, PasswordCharacters allowedCharacters,
IEnumerable <char> excludeCharacters, Func <T> initialValue, Action <T, char, int> appender)
{
if (length <= 0)
{
throw new ArgumentOutOfRangeException("length", "Password length must be greater than zero");
}
// Create a byte array the same length as the expected password and populate it with
// random bytes
var randomBytes = new byte[length];
var randomNumberGenerator = new RNGCryptoServiceProvider();
randomNumberGenerator.GetBytes(randomBytes);
// Create a string of all the characters allowed in the password
string allowedCharactersString = GenerateAllowedCharactersString(allowedCharacters, excludeCharacters);
int allowedCharactersCount = allowedCharactersString.Length;
// Create the password
T password = initialValue();
for (int i = 0; i < length; i++)
{
appender(password, allowedCharactersString[randomBytes[i] % allowedCharactersCount], i);
}
return(password);
}
/// <summary>
/// Generates a random password based on the provided criteria.
/// </summary>
/// <param name="length">The length of the password to generate</param>
/// <param name="allowedCharacters">Set of allowed characters in the generated password</param>
/// <param name="excludeCharacters">Set of disallowed characters in the generated password</param>
/// <returns>The generated password</returns>
/// <exception cref="ArgumentOutOfRangeException"></exception>
public static string Generate(int length, PasswordCharacters allowedCharacters,
IEnumerable <char> excludeCharacters)
{
char[] password = InternalGenerate(length, allowedCharacters, excludeCharacters, () => new char[length],
(pw, ch, index) => pw[index] = ch);
return(new string(password));
}
public static SecureString GenerateSecure(int length, PasswordCharacters allowedCharacters = PasswordCharacters.All,
IEnumerable <char> excludedCharacters = null)
{
if (length <= 0)
{
throw new ArgumentOutOfRangeException("length", "Password length must be greater than zero");
}
var randomBytes = new byte[length];
var randomNumberGenerator = new RNGCryptoServiceProvider();
randomNumberGenerator.GetBytes(randomBytes);
string allowedCharactersString = GenerateAllowedCharactersString(allowedCharacters, excludedCharacters);
int allowedCharactersCount = allowedCharactersString.Length;
var password = new SecureString();
for (int i = 0; i < length; i++)
{
password.AppendChar(allowedCharactersString[randomBytes[i] % allowedCharactersCount]);
}
password.MakeReadOnly();
return(password);
}
/// <summary>
/// Generates a random password based on the provided criteria and returns it as a
/// <see cref="SecureString" />.
/// </summary>
/// <param name="length">The length of the password to generate</param>
/// <param name="allowedCharacters">Set of allowed characters in the generated password</param>
/// <param name="excludeCharacters">Set of disallowed characters in the generated password</param>
/// <returns>The generated password as a <see cref="SecureString" /></returns>
/// <exception cref="ArgumentOutOfRangeException"></exception>
public static SecureString GenerateSecure(int length, PasswordCharacters allowedCharacters,
IEnumerable <char> excludeCharacters)
{
SecureString password = InternalGenerate(length, allowedCharacters, excludeCharacters,
() => new SecureString(),
(pw, ch, index) => pw.AppendChar(ch));
password.MakeReadOnly();
return(password);
}
public PasswordGenerator(
int length,
PasswordCharacters includedCharacters = PasswordCharacters.All,
char[] excludedCharacters = null)
{
Length = length;
IncludedCharacters = includedCharacters;
ExcludedCharacters = excludedCharacters;
RequiresStrongPassword = true;
}
public void Excluded_characters_are_excluded(PasswordCharacters allowedCharacters, string excludeCharacters)
{
for (int i = 0; i < 50; i++)
{
string password = PasswordGenerator.Generate(40, allowedCharacters, excludeCharacters);
foreach (char excludeChar in excludeCharacters)
{
password.ShouldNotContain(excludeChar);
}
SecureString securePassword = PasswordGenerator.GenerateSecure(40, allowedCharacters, excludeCharacters);
foreach (char excludeChar in excludeCharacters)
{
SecureStringToString(securePassword).ShouldNotContain(excludeChar);
}
}
}
private static string GenerateAllowedCharactersString(PasswordCharacters characters, IEnumerable <char> excludeCharacters)
{
var allowedCharactersString = new StringBuilder();
foreach (var type in AllowedPasswordCharacters.Where(type => (characters & type.Key) == type.Key))
{
if (excludeCharacters == null)
{
allowedCharactersString.Append(type.Value);
}
else
{
allowedCharactersString.Append(type.Value.Where(c => !excludeCharacters.Contains(c)).ToArray());
}
}
return(allowedCharactersString.ToString());
}
public static string Generate(int length, PasswordCharacters allowedCharacters = PasswordCharacters.All,
IEnumerable<char> excludeCharacters = null)
{
if (length <= 0)
throw new ArgumentOutOfRangeException("length", "Password length must be greater than zero");
var randomBytes = new byte[length];
var randomNumberGenerator = new RNGCryptoServiceProvider();
randomNumberGenerator.GetBytes(randomBytes);
string allowedCharactersString = GenerateAllowedCharactersString(allowedCharacters, excludeCharacters);
int allowedCharactersCount = allowedCharactersString.Length;
var characters = new char[length];
for (int i = 0; i < length; i++)
characters[i] = allowedCharactersString[randomBytes[i] % allowedCharactersCount];
return new string(characters);
}
private static char[] GenerateCharacters(PasswordCharacters includedCharacters, IEnumerable <char> excludedCharacters)
{
var charactersBuilder = new StringBuilder();
foreach (var character in Characters.Where(character => (character.Key & includedCharacters) == character.Key))
{
if (excludedCharacters != null)
{
charactersBuilder.Append(character.Value.Where(c => !excludedCharacters.Contains(c)).ToArray());
}
else
{
charactersBuilder.Append(character.Value);
}
}
return(charactersBuilder.ToString().ToCharArray());
}
public static SecureString GenerateSecure(int length, PasswordCharacters allowedCharacters = PasswordCharacters.All,
IEnumerable<char> excludedCharacters = null)
{
if (length <= 0)
throw new ArgumentOutOfRangeException("length", "Password length must be greater than zero");
var randomBytes = new byte[length];
var randomNumberGenerator = new RNGCryptoServiceProvider();
randomNumberGenerator.GetBytes(randomBytes);
string allowedCharactersString = GenerateAllowedCharactersString(allowedCharacters, excludedCharacters);
int allowedCharactersCount = allowedCharactersString.Length;
var password = new SecureString();
for (int i = 0; i < length; i++)
password.AppendChar(allowedCharactersString[randomBytes[i] % allowedCharactersCount]);
password.MakeReadOnly();
return password;
}
public static string Generate(int length, PasswordCharacters includedCharacters = PasswordCharacters.All, IEnumerable <char> excludedCharacters = null)
{
if (length <= 0)
{
throw new ArgumentOutOfRangeException(nameof(length), "The password length must be greater than zero.");
}
var randomCharacters = new char[length];
var characters = GenerateCharacters(includedCharacters, excludedCharacters);
var charactersLength = characters.Length;
var randomBytes = new byte[length];
var randomNumberGenerator = new RNGCryptoServiceProvider();
randomNumberGenerator.GetBytes(randomBytes);
for (var index = 0; index < length; index++)
{
randomCharacters[index] = characters[randomBytes[index] % charactersLength];
}
return(new string(randomCharacters));
}
public static string Generate(int length, PasswordCharacters allowedCharacters = PasswordCharacters.All, IEnumerable <char> excludeCharacters = null)
{
if (length <= 0)
{
throw new ArgumentOutOfRangeException("length", "Password length must be greater than zero");
}
var randomBytes = new byte[length];
var randomNumberGenerator = new RNGCryptoServiceProvider();
randomNumberGenerator.GetBytes(randomBytes);
string allowedCharactersString = GenerateAllowedCharactersString(allowedCharacters, excludeCharacters);
int allowedCharactersCount = allowedCharactersString.Length;
var characters = new char[length];
for (int i = 0; i < length; i++)
{
characters[i] = allowedCharactersString[randomBytes[i] % allowedCharactersCount];
}
return(new string(characters));
}
private static string GenerateAllowedCharactersString(PasswordCharacters characters, IEnumerable<char> excludeCharacters)
{
var allowedCharactersString = new StringBuilder();
foreach (KeyValuePair<PasswordCharacters, string> type in AllowedPasswordCharacters)
{
if ((characters & type.Key) != type.Key)
continue;
if (excludeCharacters == null)
allowedCharactersString.Append(type.Value);
else
allowedCharactersString.Append(type.Value.Where(c => !excludeCharacters.Contains(c)).ToArray());
}
return allowedCharactersString.ToString();
}
/// <summary>
/// Generates a random password based on the provided criteria and returns it as a
/// <see cref="SecureString" />.
/// </summary>
/// <param name="length">The length of the password to generate</param>
/// <param name="allowedCharacters">Set of allowed characters in the generated password</param>
/// <returns>The generated password as a <see cref="SecureString" /></returns>
/// <exception cref="ArgumentOutOfRangeException"></exception>
public static SecureString GenerateSecure(int length, PasswordCharacters allowedCharacters)
{
return(GenerateSecure(length, allowedCharacters, null));
}
public string GeneratePassword(int length, PasswordCharacters allowedCharacters)
{
return(Password = PasswordGenerator.Generate(length, allowedCharacters));
}
