So I am trying to write a program that asks for you to create a password. I have a block of code that checks to see if the string entered by the user contains a symbol. I have the code set to exit the loop when the boolean value 'validPassword' equals true.
string pleaseenterapassword = "Create a password:";
bool validPassword = false;
Console.WriteLine(pleaseenterapassword); // Writes to the screen "Create a password:"
string password = Console.ReadLine(); //Sets the text entered in the Console into the string 'password'
bool containsAtLeastOneSymbol = password.Any(char.IsSymbol);
if (containsAtLeastOneSymbol == false) // Checks if your password contains at least one symbol
{
Console.WriteLine("Your password must contain at least one symbol.");
validPassword = false;
}
This code is successful if I enter something like "Thisismypassword905+", but it does not work if I enter something like "Thisismypassword95*". I would appreciate any sort of help. Thanks in advance!
From msdn:
Valid symbols are members of the following categories in
UnicodeCategory: MathSymbol, CurrencySymbol, ModifierSymbol, and
OtherSymbol. Symbols in the Unicode standard are a loosely defined set
of characters that include the following:
- Currency symbols.
- Letterlike symbols, which include a set of
mathematical alphanumeric symbols as well as symbols such as ℅, №,
and ™.
- Number forms, such as subscripts and superscripts.
- Mathematical operators and arrows
- Geometric symbols.
- Technical symbols.
Braille patterns.
Dingbats
Update:
For juharr, who asked why does the '*' is not in the category of MathSymbol. The asterisk is not in the category of MathSymbols with this snippet you can check it. Or see this fiddle
int ctr = 0;
UnicodeCategory category = UnicodeCategory.MathSymbol;
for (ushort codePoint = 0; codePoint < ushort.MaxValue; codePoint++) {
Char ch = Convert.ToChar(codePoint);
if (CharUnicodeInfo.GetUnicodeCategory(ch) == category) {
if (ctr % 5 == 0)
Console.WriteLine();
Console.Write("{0} (U+{1:X4}) ", ch, codePoint);
ctr++;
}
}
Console.WriteLine();
Console.WriteLine("\n{0} characters are in the {1:G} category",
ctr, category);
Back to your problem. I'd do it this way:
You could use PasswordValidator
from Asp.Net Identity Framework but if you don't want to introduce such dependency is easy to extract the behavior using a couple of classes:
The validator
public class BasicPasswordPolicyValidator
{
/// <summary>
/// Minimum required length
/// </summary>
public int RequiredLength { get; set; }
/// <summary>
/// Require a non letter or digit character
/// </summary>
public bool RequireNonLetterOrDigit { get; set; }
/// <summary>
/// Require a lower case letter ('a' - 'z')
/// </summary>
public bool RequireLowercase { get; set; }
/// <summary>
/// Require an upper case letter ('A' - 'Z')
/// </summary>
public bool RequireUppercase { get; set; }
/// <summary>
/// Require a digit ('0' - '9')
/// </summary>
public bool RequireDigit { get; set; }
public virtual ValidationResult Validate(string item)
{
if (item == null)
throw new ArgumentNullException("item");
var errors = new List<string>();
if (string.IsNullOrWhiteSpace(item) || item.Length < RequiredLength)
errors.Add("Password is too short");
if (RequireNonLetterOrDigit && item.All(IsLetterOrDigit))
errors.Add("Password requires non letter or digit");
if (RequireDigit && item.All(c => !IsDigit(c)))
errors.Add("Password requires digit");
if (RequireLowercase && item.All(c => !IsLower(c)))
errors.Add("Password requires lowercase");
if (RequireUppercase && item.All(c => !IsUpper(c)))
errors.Add("Password requires uppercase");
if (errors.Count == 0)
return new ValidationResult
{
Success = true,
};
return new ValidationResult
{
Success = false,
Errors = errors
};
}
/// <summary>
/// Returns true if the character is a digit between '0' and '9'
/// </summary>
/// <param name="c"></param>
/// <returns></returns>
public virtual bool IsDigit(char c)
{
return c >= '0' && c <= '9';
}
/// <summary>
/// Returns true if the character is between 'a' and 'z'
/// </summary>
/// <param name="c"></param>
/// <returns></returns>
public virtual bool IsLower(char c)
{
return c >= 'a' && c <= 'z';
}
/// <summary>
/// Returns true if the character is between 'A' and 'Z'
/// </summary>
/// <param name="c"></param>
/// <returns></returns>
public virtual bool IsUpper(char c)
{
return c >= 'A' && c <= 'Z';
}
/// <summary>
/// Returns true if the character is upper, lower, or a digit
/// </summary>
/// <param name="c"></param>
/// <returns></returns>
public virtual bool IsLetterOrDigit(char c)
{
return IsUpper(c) || IsLower(c) || IsDigit(c);
}
}
Validation Result
public class ValidationResult
{
public bool Success { get; set; }
public List<string> Errors { get; set; }
}
Your main function:
var pleaseenterapassword = "Create a password:";
bool validPassword;
//Initialize the password validator according to your needs
var validator = new BasicPasswordPolicyValidator
{
RequiredLength = 8,
RequireNonLetterOrDigit = true,
RequireDigit = false,
RequireLowercase = false,
RequireUppercase = false
};
do
{
Console.WriteLine(pleaseenterapassword); // Writes to the screen "Create a password:"
var password = Console.ReadLine(); //Sets the text entered in the Console into the string 'password'
var validationResult = validator.Validate(password);
validPassword = validationResult.Success;
Console.WriteLine("Your password does not comply with the policy...");
foreach (var error in validationResult.Errors)
Console.WriteLine("\tError: {0}", error);
} while (!validPassword);
Hope this helps!