Regular Expression does not work correctly on webform

Question

I have the following field and validator in ASP.NET Webform

<asp:TextBox ID="txt_Senha" runat="server" CssClass="form-control" placeholder="Senha" TextMode="Password" AutoCompleteType="Disabled"></asp:TextBox>
<asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server" ControlToValidate="txt_Senha" ValidationExpression="(?=.{8,})[a-zA-Z]+[^a-zA-Z]+|[^a-zA-Z]+[a-zA-Z]+" ErrorMessage="A senha deve conter:<BR> * Mínimo 8 dígitos;<BR>* Números;<BR>* Letras MAIUSCULAS e minusculas" ForeColor="Red" />

When testing regular expression in: http://ferramentas.lymas.com.br/regexp/regexp_br.php

Works well, but on the page it does not accept the password:

1q2w3e4f5t6y7u8i

I believe it’s because there’s no Maluscula? But accept the password:

quadros2014

and quadros2014a unaccepted

Answer 1

Situation

The reason why the password 1q2w3e4f5t6y7u8i not this working is the following, in your ER you have:

(?=.{8,})    // ate aqui ok, você limitou a ter pelo menos 8 caracteres
[a-zA-Z]+    // uma ou mais quantidades de letras (alpha)
[^a-zA-Z]+   // qualquer coisa que não seja alpha, ou seja, ate mesmo estes caracteres "&¨#%"

validations:

stake%     // OK
stake4¨%   // OK
alpha!-=   // OK
casa¿@     // OK
casa$%dele // falso, pois tem 'dele' (alpha), apos [^a-zA-Z]+ (qualquer coisa exceto alpha)

after you have a |, or another possible validation:

(?=.{8,})    // ate aqui ok, você limitou a ter pelo menos 8 caracteres
[^a-zA-Z]+   // qualquer coisa que não seja alpha, ou seja, ate mesmo estes caracteres "&¨#%"
[a-zA-Z]+    // uma ou mais quantidades de letras (alpha)

validations:

%$#stake    // OK
@#$¨CASA    // OK
!varchar    // OK
teste3      // falso, pois inicio com 'teste' (alpha), primeira validacao [^a-zA-Z]+ (qualquer coisa exceto alpha)

Suggestion

To validate passwords alnum utilize:

(?=.{8,})[a-zA-Z0-9]+

validations:

1q2w3e4f5t6y7u8i  // OK
TESTE4de8         // OK
$varchar          // falso, uso de caracter `$` nao `alnum`
_cadaDele         // falso, uso de caracter `_` nao `alnum`

or if you want to release the _, simply: (?=.{8,})\w+.

Answer 2

I suggest using ^(?=.{8,})(?=.+[a-z])(?=.+[A-Z])(?=.+\d).+$

That is to say:

• (?=.{8,}) to guarantee 8 characters.
• (?=.+[a-z]) to ensure at least a small font character.
• (?=.+[A-Z]) to ensure at least one large letter character.
• (?=.+\d) to ensure at least one character that is a digit.