How to implement a regex for password validation in Swift?

Question

I want to implement a regex validaton for passwords in Swift? I have tried the following regex, but not successful

([(0-9)(A-Z)(!@#$%ˆ&*+-=<>)]+)([a-z]*){6,15}

My requirement is as follows: Password must be more than 6 characters, with at least one capital, numeric or special character

Solution 1

The regex is

(?:(?:(?=.*?[0-9])(?=.*?[-!@#$%&*ˆ+=_])|(?:(?=.*?[0-9])|(?=.*?[A-Z])|(?=.*?[-!@#$%&*ˆ+=_])))|(?=.*?[a-z])(?=.*?[0-9])(?=.*?[-!@#$%&*ˆ+=_]))[A-Za-z0-9-!@#$%&*ˆ+=_]{6,15}

Solution 2

You can use Regex for check your password strength

^(?=.*[A-Z].*[A-Z])(?=.*[!@#$&*])(?=.*[0-9].*[0-9])(?=.*[a-z].*[a-z].*[a-z]).{8}$

---

Regex Explanation : -

^                         Start anchor
(?=.*[A-Z].*[A-Z])        Ensure string has two uppercase letters.
(?=.*[!@#$&*])            Ensure string has one special case letter.
(?=.*[0-9].*[0-9])        Ensure string has two digits.
(?=.*[a-z].*[a-z].*[a-z]) Ensure string has three lowercase letters.
.{8}                      Ensure string is of length 8.
$                         End anchor.

---

Source - Rublar Link

Solution 3

try with this one for Password must be more than 6 characters, with at least one capital, numeric or special character

^.*(?=.{6,})(?=.*[A-Z])(?=.*[a-zA-Z])(?=.*\\d)|(?=.*[!#$%&? "]).*$

^ assert position at start of the string
.* matches any character (except newline)
Quantifier: * Between zero and unlimited times, as many times as possible, giving back as needed [greedy]
(?=.{6,}) Positive Lookahead - Assert that the regex below can be matched
.{6,} matches any character (except newline)
Quantifier: {6,} Between 6 and unlimited times, as many times as possible, giving back as needed [greedy]
(?=.*[A-Z]) Positive Lookahead - Assert that the regex below can be matched
.* matches any character (except newline)
Quantifier: * Between zero and unlimited times, as many times as possible, giving back as needed [greedy]
[A-Z] match a single character present in the list below
A-Z a single character in the range between A and Z (case sensitive)
(?=.*[a-zA-Z]) Positive Lookahead - Assert that the regex below can be matched
.* matches any character (except newline)
Quantifier: * Between zero and unlimited times, as many times as possible, giving back as needed [greedy]
[a-zA-Z] match a single character present in the list below
a-z a single character in the range between a and z (case sensitive)
A-Z a single character in the range between A and Z (case sensitive)
(?=.*\\d) Positive Lookahead - Assert that the regex below can be matched
.* matches any character (except newline)
Quantifier: * Between zero and unlimited times, as many times as possible, giving back as needed [greedy]
\d match a digit [0-9]
2nd Alternative: (?=.*[!#$%&? "]).*$
(?=.*[!#$%&? "]) Positive Lookahead - Assert that the regex below can be matched
.* matches any character (except newline)
Quantifier: * Between zero and unlimited times, as many times as possible, giving back as needed [greedy]
[!#$%&? "] match a single character present in the list below
!#$%&? " a single character in the list !#$%&? " literally (case sensitive)
.* matches any character (except newline)
Quantifier: * Between zero and unlimited times, as many times as possible, giving back as needed [greedy]
$ assert position at end of the string

https://regex101.com/#javascript

more this you can try ....

Minimum 8 characters at least 1 Alphabet and 1 Number:

"^(?=.*[A-Za-z])(?=.*\\d)[A-Za-z\\d]{8,}$"

Minimum 8 characters at least 1 Alphabet, 1 Number and 1 Special Character:

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

Minimum 8 characters at least 1 Uppercase Alphabet, 1 Lowercase Alphabet and 1 Number:

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

Minimum 8 characters at least 1 Uppercase Alphabet, 1 Lowercase Alphabet, 1 Number and 1 Special Character:

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

Minimum 8 and Maximum 10 characters at least 1 Uppercase Alphabet, 1 Lowercase Alphabet, 1 Number and 1 Special Character:

"^(?=.*[a-z])(?=.*[A-Z])(?=.*\\d)(?=.*[$@$!%*?&#])[A-Za-z\\d$@$!%*?&#]{8,10}"

Solution 4

public func isValidPassword() -> Bool {
    let passwordRegex = "^(?=.*\\d)(?=.*[a-z])(?=.*[A-Z])[0-9a-zA-Z!@#$%^&*()\\-_=+{}|?>.<,:;~`’]{8,}$"
    return NSPredicate(format: "SELF MATCHES %@", passwordRegex).evaluate(with: self)
}

If you need a quick fix. This is validation for a password with regex. Copy/paste in helper or extension file and use it.

Solution 5

func isValidPassword() -> Bool {
    // least one uppercase,
    // least one digit
    // least one lowercase
    // least one symbol
    //  min 8 characters total
    let password = self.trimmingCharacters(in: CharacterSet.whitespaces)
    let passwordRegx = "^(?=.*?[A-Z])(?=.*?[a-z])(?=.*?[0-9])(?=.*?[#?!@$%^&<>*~:`-]).{8,}$"
    let passwordCheck = NSPredicate(format: "SELF MATCHES %@",passwordRegx)
    return passwordCheck.evaluate(with: password)

}

for which missing validation:

func getMissingValidation(str: String) -> [String] {
    var errors: [String] = []
    if(!NSPredicate(format:"SELF MATCHES %@", ".*[A-Z]+.*").evaluate(with: str)){
        errors.append("least one uppercase")
    }
    
    if(!NSPredicate(format:"SELF MATCHES %@", ".*[0-9]+.*").evaluate(with: str)){
        errors.append("least one digit")
    }

    if(!NSPredicate(format:"SELF MATCHES %@", ".*[!&^%$#@()/]+.*").evaluate(with: str)){
        errors.append("least one symbol")
    }
    
    if(!NSPredicate(format:"SELF MATCHES %@", ".*[a-z]+.*").evaluate(with: str)){
        errors.append("least one lowercase")
    }
    
    if(str.count < 8){
        errors.append("min 8 characters total")
    }
    return errors
}

View more solutions

Comments

[Vaibhav Jhaveri]

What about this : Password must be more than 6 characters, with at least one capital, numeric or special character

[Nazmul Hasan]

^.*(?=.{6,})(?=.*[A-Z])(?=.*[a-zA-Z])(?=.*\d)|(?=.*[!#$%&? "]).*$

[Wiktor Stribiżew]

The - inside a character class creates a range, you should escape it. I have edited the answer.

[Sujal]

The explanation is helpful to better understand and hence create desired regular expression.

[Hardik Thakkar]

It is more useful if you provide short info about above Regex.

[Tosin Onikute]

@HardikThakkar You can always Google it bro!

[Hardik Thakkar]

@Html Tosin comment is for -Psajho Nub, not for you bro. With more details user who see answer can understand what will be the result of above answer.

[tBug]

@HtmlTosin I provide an answer that is working if you wont to fully understand, pls google everything about regex. Everything is self-explanatory except regex. Here is a link for more learning : regexr.com Tnx guys :)

[Keyur Tailor]

What is the significance of string in square brackets before range in all these regex? We don't provide these square brackets in javascript regex.

[Mohsin Khubaib Ahmed]

+~`^-_= are also special characters but are not being entertained in these expressions as Alphanumeric characters

[Hardik Darji]

nice explanation

[Sandeep Maurya]

it fails for @Abc12345678

[mshrestha]

how about at least one uppercase, one numeric and no special character? @NazmulHasan

[Bartłomiej Semańczyk]

you are awesome;)

[Ximena Flores de la Tijera]

Is there a way to know which validation is missing and return set error?

[Pintu Rajput]

I need same validation but different cases, so that find which validation is missing

[Yuyutsu]

@XimenaFloresdelaTijera @PintuRajput added the getMissingValidation function