ASP.NET Password Strength Regular Expression

Try with this:

ValidationExpression="(?=^.{7,51}$)([A-Za-z]{1})([A-Za-z0-9!@#$%_\^\&\*\-\.\?]{5,49})$" 

Here you can find lot of samples

If you are trying to escape the " and this is in your web.config file, you need to do ", that is the proper quote entity for xml. As for the regex you want, try this

^(?=[a-z]+)(?=.*?\d+)(?=.*?[`~!@#$%^&*\(\)\-_}{\]\[=+\\|]+).{7,}$

Will match against the following items in bold

• helloth
• hellot
• hell0th
• hell0Th
• he!l0th
• he!l0Th
• he!l0Th3534534
• he!l0Thdggfsg

You can add (?=.*?[A-Z]+) if you also want to require at least one upper case letter, and make it only match the last 3. Finally, you can modify the following block from the regex above to include only the special chars you want to allow.

[`~!@#$%^&*\(\)\-_}{\]\[=+\\|]

Instead of dealing with an expression no one understands, use three (or more). There following is some pseudo code for this idea:

abort('to short') if password.length < 8
abort('at least one letter') if password !~ /[a-z]/i
abort('at least two digits') if password !~ /[0-9].*[0-9]/
abort('at least one special character') if password !~ /[!@#$%^\*-=\+\?]/

'Added by Itrend solutions -Password Validation

Create a method and pass your text to validate the password strength .. Dim password AsString password = Trim(txtnewpassword.Text)

DimSmallCharacter() AsString = {"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z", "A", "B", "C", "D", "E", "F", "G", "H", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"} DimsmallchacountAsInteger = 0 ForEachsmallchaAsStringInSmallCharacter If (password.Contains(smallcha)) Then smallchacount = smallchacount + 1 EndIf Next Ifsmallchacount<= 0 Then MessageBox("Password Must Contain One Alphabet Character") Exit Sub EndIf

Dim Numbers() AsString = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9"} DimnumbercountAsInteger = 0 ForEachnumAsStringIn Numbers If (password.Contains(num)) Then numbercount = numbercount + 1 EndIf Next Ifnumbercount<= 0 Then MessageBox("Password Must Contain One Numeric Digit") Exit Sub EndIf

DimSpecial() AsString = {"@", "#", "$", "%", "^", "&", "*", "(", ")", "!"} DimcountSpecialAsInteger = 0 ForEach spec AsStringIn Special If (password.Contains(spec)) Then countSpecial = countSpecial + 1 EndIf Next IfcountSpecial<= 0 Then MessageBox("Password Must Contain One Special Character") Exit Sub

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