CODEWITHSUNDEEP
phpregex
MrPizzaFace
MrPizzaFace

Reputation: 8086

PHP regex for password validation

I not getting the desired effect from a script. I want the password to contain A-Z, a-z, 0-9, and special chars.

So I want to force the user to use at least 2 digits and at least 2 special chars. Ok my script works but forces me to use the digits or chars back to back. I don't want that. e.g. password testABC55$$ is valid - but i don't want that.

Instead I want test$ABC5#8 to be valid. So basically the digits/special char can be the same or diff -> but must be split up in the string.

PHP CODE:

$uppercase = preg_match('#[A-Z]#', $password);
$lowercase = preg_match('#[a-z]#', $password);
$number    = preg_match('#[0-9]#', $password);
$special   = preg_match('#[\W]{2,}#', $password); 
$length    = strlen($password) >= 8;

if(!$uppercase || !$lowercase || !$number || !$special || !$length) {
  $errorpw = 'Bad Password';

Upvotes: 4

Views: 10823

Answers (4)

James
James

Reputation: 11

This will do the trick. Look ahead is nice for this...

/^(?=.*[a-z])(?=.*[A-Z])(?=.*\d.*\d)(?=.*\W.*\W)[a-zA-Z0-9\S]{4,}$/

EXPLAINED in pieces below

Look ahead/require for a lower case:

(?=.*[a-z])

Look ahead/require an uppercase:

(?=.*[A-Z])

Look ahead/require 2 digits:

(?=.*\d.*\d)

Look ahead/require any 2 non-word chars (same as [^a-zA_Z0-9_]):

(?=.*\W.*\W)

Entire password must contain a minimum of 4, a maximum is not defined, and only alpha numeric and special chars (non white-space):

[\S]{4,}

Upvotes: 0

Sibin John Mattappallil
Sibin John Mattappallil

Reputation: 1789

For matching length of string including special characters:

$result = preg_match('/^(?=.[a-z])(?=.[A-Z])(?=.\d)(?=.[^A-Za-z\d])[\s\S]{6,16}$/', $string);

Answer explained: https://stackoverflow.com/a/46359397/5466401

Upvotes: 0

Ωmega
Ωmega

Reputation: 43673

Using "readable" format (it can be optimized to be shorter), as you are regex newbie >>

^(?=.{8})(?=.*[A-Z])(?=.*[a-z])(?=.*\d.*\d.*\d)(?=.*[^a-zA-Z\d].*[^a-zA-Z\d].*[^a-zA-Z\d])[-+%#a-zA-Z\d]+$

Add your special character set to last [...] in the above regex (I put there for now just -+%#).

Explanation:

^                              - beginning of line/string
(?=.{8})                       - positive lookahead to ensure we have at least 8 chars
(?=.*[A-Z])                    - ...to ensure we have at least one uppercase char
(?=.*[a-z])                    - ...to ensure we have at least one lowercase char
(?=.*\d.*\d.*\d                - ...to ensure we have at least three digits
(?=.*[^a-zA-Z\d].*[^a-zA-Z\d].*[^a-zA-Z\d]) 
                               - ...to ensure we have at least three special chars
                                    (characters other than letters and numbers)
[-+%#a-zA-Z\d]+                - combination of allowed characters
$                              - end of line/string

Upvotes: 12

burning_LEGION
burning_LEGION

Reputation: 13450

((?=(.*\d){3,})(?=.*[a-z])(?=.*[A-Z])(?=(.*[!@#$%^&]){3,}).{8,})

test$ABC5#8 is not valid because you ask more than 2 digits and spec symbols

A-Z
a-z
0-9 > 2
special chars > 2
string length >= 8

Upvotes: 1

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