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Password strength requirements are a hot topic as of late due to a slew of compromised sites and services exposing millions of user accounts to hackers. To no one�s surprise, the most used passwords are embarrassingly weak. �password� anyone?The first step in a long process of securing any service with user accounts is enforcing a password policy of sufficient complexity.

This can be done in a number of ways programmatically by creating the proper logic during the registration process, but that solution is specific to each scenario. A more general solution is to use RegEx (regular expressions) to define a pattern that meets your desired requirements.Regular expressions are as complicated as they are powerful.

They can be very intimidating in the beginning, so the best way to start is to take an example and tweak it until you produce exactly what you need. It also helps to list out your goals before you begin.For this example, the rules I would like to enforce are:�The password length must be greater than or equal to 8�The password must contain one or more uppercase characters�The password must contain one or more lowercase characters�The password must contain one or more numeric values�The password must contain one or more special charactersThose are a lot of requirements.

Amazingly, all of those requirements can be expressed in a single line of a regular expression:(?=^.{8,}$)(?=.*d)(?=.*[!@#$%^&*]+)(?![. ])(?=.*[A-Z])(?=.*[a-z]).*$Rubular LinkGranted, that single line RegEx looks like a random garble of characters at first glance.

In reality, it is a password strength regex constructed set of rules to dictate a pattern match on a string. As a primer, have a look at the RegEx syntax guide, then load up a RegEx tester like Rubular and start playing around with different combinations until you get a feel for it.Once you have your expression written, implementing it in the programming language of your choice is trivial as RegEx is well supported in nearly every language.Read more of Matthew Mombrea's ByteStream blog and follow Matt on Twitter ( @mombrea) and Google+.

For the latest IT news, analysis and how-tos, follow ITworld on Twitter and Facebook. Matthew MombreaMatthew Mombrea is a software engineer, founder of Cypress North, and a technology enthusiast.The opinions expressed in this blog are those of the author and do not necessarily represent those of ITworld, its parent, subsidiary or affiliated companies.����� Explore the IDG Network descend� CIO� Computerworld� CSO� Greenbot� IDC� IDG� IDG Answers� IDG Connect� IDG Knowledge Hub� IDG TechNetwork� IDG.TV� IDG Ventures� Infoworld� IT News� ITwhitepapers� ITworld� JavaWorld� LinuxWorld� Macworld� Network World� PC World� TechConnect� TechHive �TourStart here for a quick overview of the site�Help CenterDetailed answers to any questions you might have�MetaDiscuss the workings and policies of this site�About UsLearn more about Stack Overflow the company�BusinessLearn more about hiring developers or posting ads with us Announcing Stack Overflow DocumentationWe started with Q&A.

Technical documentation is next, and we need your help.Whether you're a beginner or an experienced developer, you can contribute.Sign up and start helping >Learn more about Documentation > My password strength criteria is as below :� 8 characters length� 2 letters in Upper Case� 1 Special Character (!@#$&*)� 2 numerals (0-9)� 3 letters in Lower CaseCan somebody please give me regex for same. All conditions must be met by password . @Borealid: publishing your password policies should usually not significantly impact your security.

If it does, then your policies are bad ("Only password and hello123 are valid passwords!").� Joachim Sauer Feb 28 '11 at password strength regex password rules will usually not lead to more safe passwords, important is only a minimum length.

People cannot remember tons of strong passwords, and such rules can interfere with good password schemes. People can get very inventive to bypass such rules, e.g. by using weak passwords like "Password-2014". Often you end up with weaker passwords instead of stronger ones.� martinstoeckli Oct 24 '14 at 12:28 You can do these checks using positive look ahead assertions: ^(?=.*[A-Z].*[A-Z])(?=.*[!@#$&*])(?=.*[0-9].*[0-9])(?=.*[a-z].*[a-z].*[a-z]).{8}$Rubular linkExplanation: ^ 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. Positive look ahead is exactly the thing to use for this kind of things.

Here's mine : ^(?=.*[A-Z])(?=.*[a-z])(?=.*[0-9]).{8,24}$ (between 8 and 24 chars, at least one of each type among lowercase, uppercase, and numbers)� AFract Aug 31 '15 at 15:43 You can use zero-length positive look-aheads to specify each of your constraints separately: (?=.{8,})(?=.*p{Lu}.*p{Lu})(?=.*[!@#$&*])(?=.*[0-9])(?=.*p{Ll}.*p{Ll})If your regex engine doesn't support the p notation and pure ASCII is enough, then you can replace p{Lu} with [A-Z] and p{Ll} with [a-z]. Answers given above are perfect but I suggest to use multiple smaller regex rather than a big one.Splitting the long regex have some advantages:� easiness to write and read� easiness to debug� easiness to add/remove part of regexGenerally this approach keep code easily maintainable.Having said that, I share a piece of code that I write in Swift as example: struct RegExp {/**Check password complexity- parameter password: password to test- parameter length: password min length- parameter patternsToEscape: patterns that password must not contains- parameter caseSensitivty: specify if password must conforms case sensitivity or not- parameter numericDigits: specify if password must conforms contains numeric digits or not- returns: boolean that describes if password is valid or not*/static func checkPasswordComplexity(password password: String, length: Int, patternsToEscape: [String], caseSensitivty: Bool, numericDigits: Bool) -> Bool {if (password.length < length) {return false}if caseSensitivty {let hasUpperCase = RegExp.matchesForRegexInText("[A-Z]", text: password).count > 0if !hasUpperCase {return false}let hasLowerCase = RegExp.matchesForRegexInText("[a-z]", text: password).count > 0if !hasLowerCase {return false}}if numericDigits {let hasNumbers = RegExp.matchesForRegexInText("d", text: password).count > 0if !hasNumbers {return false}}if patternsToEscape.count > 0 {let passwordLowerCase = password.lowercaseStringfor pattern in patternsToEscape {let hasMatchesWithPattern = RegExp.matchesForRegexInText(pattern, text: passwordLowerCase).count > 0if hasMatchesWithPattern {return false}}}return true}static func matchesForRegexInText(regex: String, text: String) -> [String] {do {let regex = try NSRegularExpression(pattern: regex, options: [])let nsString = text as NSStringlet results = regex.matchesInString(text,options: [], range: NSMakeRange(0, nsString.length))return results.map { nsString.substringWithRange($0.range)}} catch let error as NSError {print("invalid regex: (error.localizedDescription)")return []}}} codaddict's solution works fine, but this one is a bit more efficient: (Python syntax) password = re.compile(r"""(?#!py password Rev:20160831_2100)# Validate password: 2 upper, 1 special, 2 digit, 1 lower, 8 chars.^ # Anchor to start of string.(?=(?:[^A-Z]*[A-Z]){2}) # At least two uppercase.(?=[^!@#$&*]*[!@#$&*]) # At least one "special".(?=(?:[^0-9]*[0-9]){2}) # At least two digit.{8,} # Password length is 8 or more.$ # Anchor to end of string.""", re.VERBOSE)*The negated character classes consume everythin�TourStart here for a quick overview of the site�Help CenterDetailed answers to any questions you might have�MetaDiscuss the workings and policies of this site�About UsLearn more about Stack Overflow the company�BusinessLearn more about hiring developers or posting ads with us I've been following a Python programming book and reached the Regex chapter where I password strength regex this challenge:Write a password strength checker that checks if a password is:� At least 8 character long� Contains at least one uppercase and lowercase letter.� And contains at least one digit.I managed to do so, but frankly my solution seems both long and ugly.

I was hoping someone could shed some light as to how I could maybe condense my program and improve readability if possible. import redef is_password_strong():password = input('Enter a password to test: ')length_regex = re.compile(r'.{8,}')length = True if length_regex.search(password) != None else Falseuppercase_regex = re.compile(r'[A-Z]')lowercase_regex = re.compile(r'[a-z]')uppercase = True if uppercase_regex.search(password) != None else Falselowercase = True if lowercase_regex.search(password) != None else Falsecase = True if uppercase and lowercase == True else Falsedigit_regex = re.compile(r'[0-9]')digit = True if digit_regex.search(password) != None else Falsereturn(length and case and digit == True)print(is_password_strong())And here is my non-regex solution if you can't read the above and want to see what I am trying to do with regex: def is_password_strong():password = input('Enter a password to test: ')length = len(password) >= 8case = password != password.upper() and password != password.lower()digit = any(c.isdigit() for c in password)return(length and case and digit == True)I know this isn't a good test of password strength, but it was the book's challenge.

I'm not implementing it for any real use. Here are the major comments:�Ideally functions should do one thing at once. Your function is doing two: (1) asking the user for a password and (2) evaluating the strength of that password.You should break this code into two functions: (1) ask_user_for_password() and (2) is_password_strong(password).�Regexes are not always the right tool for the job.

(I appreciate this is a chapter on regexes, but the point has to be made.)Python has fairly powerful string manipulation tools. You should reach for those before opening your regex toolbox � I think the Python constructs are usually much easier to read and debug. Brownie points for writing a version that doesn�t use regexes � I would almost always prefer this version in a �real� codebase.�Be lazy about evaluation.

This function is fairly fast, because it doesn�t have many checks. Even so, you can save yourself a little work � as soon as a check fails, you can return False.(It�s fine to bail out early for a password strength evaluation.

Try to avoid doing this when doing real authentication � if your function takes noticeably different time depending on what�s wrong with the function, you�re vulnerable to a timing attack.)�Your function should have a docstring.

Docstrings are the preferred way to document functions in Python. For this function, it should be fairly simple - it evaluates a password, and returns True/False depending on whether it meets certain criteria - but you should still write it.And a few nitpicks:�Compare to None with �is�, not �==� and �!=�.It�s always preferred to check using �is�, which checks identity, not equality � this makes sure the object you�re dealing with really is None, and not a class with a strange equality operator.

It�s also faster.�You can tidy up your booleans.Quite a few of your lines boil down to: result = True if (check != None) else FalseThis line reduces to: result = (check is not None)That�s more readable and direct.Then your final boolean can be reduced to: return (length and case and digit)which is equivalent.�Put your main code in an if __name__ == '__main__' block.

This means that it only runs when the file is called directly � not, for example, when it�s imported as a module.This makes your code easier to reuse. In your regex solution, rather than using two temporary values, I'd find it more readable to just evaluate case directly: case = (uppercase_regex.search(password) is not None andlowercase_regex.search(password) is not None)This is both readable and makes use of short circuiting.

This means that if uppercase_regex.search(password) is not None evaluates as False then Python already knows the value of case is False and it doesn't bother searching the other regex.If you wanted, you could even employ short circuiting with all four tests in your return statement, instead of searching after each compile: def is_password_strong():password = input('Enter a password to test: ')length_regex = re.compile(r'.{8,}')uppercase_regex = re.compile(r'[A-Z]')lowercase_regex = re.compile(r'[a-z]')digit_regex = re.compile(r'[0-9]')return (length_regex.search(password) is not Noneand uppercasToggle navigation� Android� Java Core� Java I/O� Java XML� Java JSON� Java RegEx� JDBC� Spring� Spring Core� Spring MVC� Spring Security� Spring Data MongoDB� Spring Batch� Frameworks� JSF 2.0� Hibernate ORM� Apache Wicket� Struts 1� Struts 2� JAX-RS (REST)� JAX-WS (SOAP)� jUnit� TestNG� Misc� Google App Engine� Apache Ant� Apache Maven� jQuery� Java MongoDB� Quartz Scheduler� Log4j� Contact Us� Password Regular Expression Pattern((?=.*d)(?=.*[a-z])(?=.*[A-Z])(?=.*[@#$%]).{6,20})Description( # Start of group(?=.*d) # must contains one digit from 0-9(?=.*[a-z]) # must contains one lowercase characters(?=.*[A-Z]) # must contains one uppercase characters(?=.*[@#$%]) # must contains one special symbols in the list "@#$%".

# match anything with previous condition checking{6,20} # length at least 6 characters and maximum of 20) # End of group?= � means apply the assertion condition, meaningless by itself, always work with other combinationWhole combination is means, 6 to 20 characters string with at least one digit, one upper case letter, one lower case letter and one special symbol (�@#$%�).

This regular expression pattern is very useful to implement a strong and complex password.P.S The grouping formula order is doesn�t matter. 1. Java Regular Expression Example PasswordValidator.javapackage com.mkyong.regex;import java.util.regex.Matcher;import java.util.regex.Pattern;public class PasswordValidator{private Pattern pattern;private Matcher matcher;private static final String PASSWORD_PATTERN ="((?=.*d)(?=.*[a-z])(?=.*[A-Z])(?=.*[@#$%]).{6,20})";public PasswordValidator(){pattern = Pattern.compile(PASSWORD_PATTERN);}/*** Validate password with regular expression* @param password password for validation* @return true valid password, false invalid password*/public boolean validate(final String password){matcher = pattern.matcher(password);return matcher.matches();}} 3.

Password that doesn�t match:1. mY1A@too short, minimum 6 characters2. mkyong12@uppercase characters is required3. mkyoNg12*special symbol �*� is not allow here4. mkyonG$$, digit is required5. MKYONG12$lower case character is required 4. Unit Test � PasswordValidatorUnit test with TestNG. PasswordValidatorTest.javapackage com.mkyong.regex;import org.testng.Assert;import org.testng.annotations.*;/*** Password validator Testing* @author mkyong**/public class PasswordValidatorTest {private PasswordValidator passwordValidator;@BeforeClasspublic void initData(){passwordValidator = new PasswordValidator();}@DataProviderpublic Object[][] ValidPasswordProvider() {return new Object[][]{{new String[] {"mkyong1A@", "mkYOn12$",}}};}@DataProviderpublic Object[][] InvalidPasswordProvider() {return new Object[][]{{new String[] {"mY1A@","mkyong12@","mkyoNg12*","mkyonG$$","MKYONG12$"}}};}@Test(dataProvider = "ValidPasswordProvider")public void ValidPasswordTest(String[] password) {for(String temp : password){boolean valid = passwordValidator.validate(temp);System.out.println("Password is valid : " + temp + "" + valid);Assert.assertEquals(true, valid);}}@Test(dataProvider = "InvalidPasswordProvider",dependsOnMethods="ValidPasswordTest")public void InValidPasswordTest(String[] password) {for(String temp : password){boolean valid = passwordValidator.validate(temp);System.out.println("Password is valid : " + temp + "" + valid);Assert.assertEquals(false, valid);}}}5.

Unit Test � ResultPassword is valid : mkyong1A@truePassword is valid : mkYOn12$truePassword is valid : mY1A@falsePassword is valid : mkyong12@falsePassword is valid : mkyoNg12*falsePassword is valid : mkyonG$$falsePassword is valid : MKYONG12$falsePASSED: ValidPasswordTest([Ljava.lang.String;@1d4c61c)PASSED: InValidPasswordTest([Ljava.lang.String;@116471f)===============================================com.mkyong.regex.PasswordValidatorTestTests run: 2, Failures: 0, Skips: 0==============================================================================================mkyongTotal tests run: 2, Failures: 0, Skips: 0=============================================== mkyong Founder of Mkyong.com and HostingCompass.com, love Java and open source stuff.

Follow him on Twitter, or befriend him on Facebook or Google Plus. If you like my tutorials, consider make a donation to these charities. Popular Posts >�Pingback: xmdxuyf8x4c5ygniwx4dyf4wcn5gxtdf()�Pingback: xm85cws8txym3845ncnwsxsf4s()�Pingback: zwtxk85wyt4zsefx4mtgergfer()�Pingback: s4k5jtwy48dcngg5mxdrtdncrt()�Pingback: x2m5ttttt55dsywzfwmx34rx34()�Pingback: cn7v5jdncgsdjkx4m9c5nyecen()�Pingback: z3c33mxcwnte5dtgeurws0gfff()�Pingback: c8n75s5tsndxcrsfsfcscjkfsk()�Pingback: ccn2785xdnwdc5bwedsj4wsndb()�Pingback: https://webkingz.camkingz.com/()�Pingback: read more()�Pingback: water ionizer()�Pingback: alkaline water()�Pingback: electricity()�Pingback: pay plan()�Pingback: paypal loans()�Pingback: pay day loans() � Android Getting Started� Google App Engine � Java� Spring 2.5.x Documentation� Spring 3.2.x Documentation� Spring 4GoSoftware Development & IT Outsourcing� About Us� Careers� Contact� Blog� Home� Company� About Us� Careers� News� Contact Us� Client Testimonials� IT Services� Application Development� Software Maintenance Services� Application Migration� ColdFusion Application Development� Database Development Services� IT Software outsourcing company� Industries� Retail Software� Healthcare Software� Education Software� Events Software� Engineering Software� Realty & Mortgage Software� Hospitality Software� Media & Entertainment Software� Shipping & Logistics Software� Products� Portals� ERP Systems� Resources� Case Studies Complex password strength checking through regular expressionCurrently working on project for well non credit card company where they have online registration form.

They really want user enter enter strong password for their account and criteria for password listed below.� Password must length between 8 to 18.� Password must contain atleast one alpha and on numeric.� Password must have one special characters from @,#,$.� Password can not have repeative alpha and numeric.This is really complex but can be done with four different conditions easily (right?) but I decided to make things more complex and check all four condition with single regular expression.

After spending time on this finally figure out regular expression can perform all four condition.Here is megical regular expression.(?=^.{8,18}$)(?=^[dA-Za-z@#$]*$)(?=.*[@##$]?)(?=.*d+)(?=.*[A-Za-z]+)(?!.*([da-zA-Z])(.*)
)Lets devide it and rule.(?=^.{8,18}$) - This will check for length of password between 8 to 18 characters.(?=^[dA-Za-z@#$]*$) - This make sure we enter digit,alpha and special characters from @,#,$.

Not other than this will allowed.(?=.*d+) - This will make sure we have atleast one digit in regular expression.(?=.*[A-Za-z]+) - This is for to make sure atleast one alpha.(?!.*([da-zA-Z])(.*)
) - Here is megical one to check no repeating characters (alpha and digits only)Only issue found it if you try to check with ColdFusion isValid function then it will not work but REMATCH will work fine.REMATCH -
ISVALID - #isValid("Regex","iam8l$ng",reg)#Here is output :[addcfcode]REMATCH -
ISVALID - #isValid("Regex","iam8l$ng",reg)#[/addcfcode]I think isValid doesn't able to validate because it return emptystring but I am able to put conidtion based on array length return from REMATCH.Hope this help. Categories� Ajax (9)� Ajax Application Development (9)� Ajax Software Development (9)� Android (9)� Application Design (9)� Application Development (9)� Application Integration (9)� Application Maintenance (9)� Application Migration (9)� Application Migration Services (9)� Application Security (9)� Application Security Management (9)� Application Software Integration (9)� Application Software Maintenance (9)� Application Software Migration (9)� BlackBerry (11)� CaseStudy (9)� Cloud (11)� ColdFusion (9)� ColdFusion (9)� ColdFusion (131)� ColdFusion 5 (10)� ColdFusion 9 (35)� ColdFusion Application & Software Development (9)� ColdFusion Application & Software Development (9)� Coldfusion Software Development (9)� ColdFusion Software Development & Programming (9)� ColdFusion X (26)� Consulting Services (9)� Content Management (9)� Content Management System (9)� Content Management System (9)� Custom Application & Software Development (9)� Custom Application & Software development (9)� Data Migration (9)� Database Design (9)� Database Development Services (9)� Desktop Application Development (9)� Desktop Software Development (9)� Document Management (9)� Document Management System (9)� Document Management System (9)� DVD Rental (9)� DVD Rental (9)� DVD Rental Software (9)� E-Commerce Software Development (9)� Ecommerce software Development (9)� Education (9)� Education Software & Applications (9)� Educational Software (9)� Engineering (9)� Engineering Software & Development (9)� Engineering Software Development (9)� Enterprise Application development (9)� Enterprise Application Development (9)� ERP (9)� ERP Software (9)� ERP Software Development (9)� Event Management (9)� Event Management (9)� Event Management Software (9)� Event software & Application (9)� Finance & Mortgage (9)� Flex (11)� Healthcare (9)� Healthcare Software (9)� Healthcare Software & Applications (9)� home page_real (9)� homepage (9)� Homepage (9)� Hospitality (9)� Hospitality Software (9)� HTML (16)� HTML 5 (11)� Industry (9)� iPhone (10)� JavaScript (18)� Jewelery (9)� Jewelry Software (9)� Jewelry Software & Application (9)� jQuery (32)� jQuery Mobile (13)� Legacy software management (9)� Legacy Systems ManagemSearch Search for: Pages� About Geoff Lane� Geoff Lane�s ResumeRecent Posts� Using A Core.Async Routine As A State Machine� High Performance and Parallelism With the Feel of a Scripting Language� 3.5x Increase In Performance with a One-Line Change� Mapping SQL Joins using Anorm� Java 7 Code Coverage with Gradle and JacocoTags ajax apache asp.net Automation blogging capistrano compact framework continuous integration cruisecontrol csharp database DOJO-Toolkit dsl erlang exercises firefox functional programming grails groovy hibernate hql HTML Java JSON Life meta-programming mock-objects mongodb msbuild nunit ObjectBuilder orm performance rails rest ruby-on-rails software-development sql subversion Unit Testing validation version-control WebDAV windows-mobile WordPress xml Categories� .NET� Automation� Book Review� C� Clojure� Code� Erlang� Go� Groovy� Java� Javascript� Life� Mac OS X� Python� Ruby� Scala� Scheme� Unit Testing� Web� WebDAVMeta� Log in� Entries RSS� Comments RSS� WordPress.org Regular Expressions are both complex and elegant at the same time.

They can be made to look like someone was just randomly hammering on their keyboard. They are also an incredibly efficient and elegant solution to describing the structure of text and matching those structures.

They are very handy for defining what a string should look like and as such are very good for use in data validation.To validate a US phone number you might create a simple regular expression d{3}-d{3}-d{4} which will match a phone number like 123-555-1212. Where regular expressions can become difficult though is when the format is not quite as clear cut.

What if we need to support (123) 555-1212 and just 555-1212? Well that�s where things can get more complex. But this is not about validating phone numbers. In this post I will look at how to make assertions about the complexity of a string, which is very useful if you want to enforce complexity of a user created password.The key to making password strength validation easy using Regular Expressions is to understand Zero-width positive lookahead assertions (also know as zero-width positive lookaheads).

Now that�s a mouthful isn�t it? Luckily the concept itself is a lot simpler than the name. Zero-width positive lookahead assertionsBasically a Zero-width positive lookahead assertion is simply an assertion about a match existing or not. Rather than returning a match though, it merely returns true or false to say if that match exists. It is used as a qualification for another match.The general form of this is:(?= some_expression)For example:�The regular expression z matches the z in the string zorched.�The regular expression z(?=o) also matches the z in the string zorched.

It does not match the zo, but only the z.�The regular expression z(?=o) does NOT match the z in the string pizza because the assertion of z followed by an o is not true.Making Assertions About Password ComplexityNow that you know how to make assertions about the contents of a string without actually matching on that string, you can start deciding what you want to actually assert.

Remember that on their own these lookaheads do not match anything, but they modify what is matched.Assert a string is 8 or more characters:(?=.{8,})Assert a string contains at least 1 lowercase letter (zero or more characters followed by a lowercase character):(?=.*[a-z])Assert a string contains at least 1 uppercase letter (zero or more characters followed by an uppercase character):(?=.*[A-Z])Assert a string contains at least 1 digit:(?=.*[d])Assert a string contains at least 1 special character:(?=.*[W])Assert a string contains at least 1 special character or a digit:(?=.*[dW])These are of course just a few common examples but there are many more that you could create as well.

Applying Assertions to Create a Complexity ValidationKnowing that these make assertions about elements in a string, but not about a match itself, you need to combine this with a matching regular expression to create you match validation.* matches zero or more characters.^ matches the beginning of a string.$ matches the end of a string.Put together ^.*$ matches any single line (including an empty line). With what you know about Zero-width positive lookahead assertions now you can combine a �match everything� with assertions about that line to limit what is matched.If I want to match password strength regex line with at least 1 lowercase character then I can use:^.

(?=.[a-z]).*$(Which reads something like: start of string, zero or more characters, assert that somewhere in the string is a lowercase character, zero or more trailing characters, the end of the string)The part that makes this all interesting is that you can combine any number of assertions about the string into one larger expression that will create your rules for complexity.

So if you want to match a string at least 6 characters long, with at least one lower case and at least one uppercase letter you could use something like:^. (?=.{6,}� Regex Cheat Sheet� Search� Regex Tester� Browse Expressions� Add Regex� Manage My Expressions� Contributors� Regex Resources� Web Services� Advertise� Contact Us� Register� Recent Expressions� Recent Comments � Michael Ash (55)� Steven Smith (42)� Matthew Harris (35)� tedcambron (29)� PJWhitfield (28)� Vassilis Petroulias (26)� Matt Brooke (22)� Juraj Hajduch (SK) (21)� Raymonddup (21)� Amit kumar sinha (19)� All Contributors The password's first character must be a letter, it must contain at least 4 characters and no more than 15 characters and no characters other than letters, numbers and the underscore may be usedMatches Will match a VBScript string and/or commentEx:' userinfostrUsername = "tomsve"iAge = 20' tempstrPassword = "halloj".Would result in the following matches:' userinfo"tomsve"' temp"halloj"Good luck!Tom info@tomsvensson.comMatches Password expresion that requires one lower case letter, one upper case letter, one digit, 6-13 length, and no spaces.

This is merely an extension of a previously posted expression by Steven Smith (ssmith@aspalliance.com). The no spaces is new.Matches A general string validation to insure no malicious code is being passed through user input. General enough too allow email address, names, address, passwords, so on.

Disallows �,*&$<> or other characters that could cause issues.Matches This is an update of Paul Miller's RegEx. It will cut out literal &lt;&gt; but I haven't fully tested it, it's just a quick fix since his didn't work all that well.I also took out the s. You could add this back in but I use this for very simple password verification, and I certainly have no use for spaces in my passwords.Matches I built this expression to test a string in ASP for valid username and password constraints.

It can be adapted for any number of scenerios. For instance in this case, we needed to ensure the username someone wanted was not all numbers or all letters and was 6-15 characters in length with no special characters. This expression tests negatively for all number cases, then all letter cases, and lastly tests for only alphanumeric characters in the required range.

In other words: the match must be alphanumeric with at least one number, one letter, and be between 6-15 character in length.Matches This regex can be used to restrict passwords to a length of 8 to 20 aplhanumeric characters and select special characters. The password also can not start with a digit, underscore or special character and must contain at least one digit.Matches THE Complex Password Filter Matching 3 of 4 Character catagories:1.) at least 1 upper case character2.) at least 1 lower case character3.) at least 1 numerical character4.) at least 1 special characterIt also enforces a min and max length and works for .Net and script Regex implimentations.Matches (?:Provider="??(?[^; ]+)"??[; "]??|DatasSource=(?[^; ]+)[; "]??|InitialsCatalog=(?[^; ]+)[; "]??|UsersID=(?[^; ]+)[; "]??|Password="??(?[^; ]+)"??[; "]??|IntegratedsSecurity=(?[^; ]+)[; ]??|ConnectionsTimeOut=(?[^; ]+)[; "]??)+$Description This RegExp is degigned to mach SQL OLEDB Connection String to the Named Groups Properties useful for .Net MATCH EXAMPLE(the submition field is too short):Provider="SQLOLEDB.1";Data Source=(local);Initial Catalog=master;User ID=sa;Password="SA_PASS";Connection TimeOut=90Matches This regular expression match can be password strength regex for validating strong password.

It expects atleast 1 small-case letter, 1 Capital letter, 1 digit, 1 special character and the length should be between 6-10 characters. The sequence of the characters is not important. This expression follows the above 4 norms specified by microsoft for a strong password.Matches Recently one of my Twitter followers asked me how they might validate password strength using regular expressions (RegEx) in their code.Regular expressions via Wikipedia:A sequence of characters that forms a search pattern, mainly for use in pattern matching with strings, or string matching.RegEx is nice because you can accomplish a whole lot with very little.

In this case we are going to check various aspects of a string and see if it meets our requirements, being a strong or medium strength password.In this example, I�m going to use a mixture of AngularJS and vanilla JavaScript. Basically, the JavaScript will do all the heavy lifting and the AngularJS code will be responsible for binding it all to the screen.To show the password strength to the user, we�re going to use a rectangle that contains a color.

We�ll say that a red rectangle holds a weak password, orange medium, and green a strong password. The HTML behind this would look something like the following:

There is, however, a few pieces of AngularJS code that we�ll see in a moment.The passwordStrength variable that you see in the ng-style tag holds all the styling information for the strength rectangle. The style information we�re going to use is as follows: $scope.passwordStrength = {"float": "left","width": "100px","height": "25px","margin-left": "5px"};Moving beyond the basic AngularJS stuff, lets get down to the good stuff.

We�re going to make use of two different RegEx validation strings. One string will represent what is required for creating a strong password and the other will represent what is necessary for creating a medium strength password. If neither expressions are satisfied, we�ll assume it is poor strength. var strongRegex = new RegExp("^(?=.*[a-z])(?=.*[A-Z])(?=.*[0-9])(?=.*[!@#$%^&*])(?=.{8,})");bove you can see the expression for validating a strong password.

Let�s break down what it is doing. RegExDescription^The password string will start this way(?=.*[a-z])The string must contain at least 1 lowercase alphabetical character(?=.*[A-Z])The string must contain at least 1 uppercase alphabetical character(?=.*[0-9])The string must contain at least 1 numeric character(?=.*[!@#$%^&*])The string must contain at least one special character, but we are escaping reserved RegEx characters to avoid conflict(?=.{8,})The string must be eight characters or longerThat wasn�t so bad!

So how about our medium strength validator? There is less precision in this one, thus making it necessary to create a more complex regular expression. var mediumRegex = new RegExp("^(((?=.*[a-z])(?=.*[A-Z]))|((?=.*[a-z])(?=.*[0-9]))|((?=.*[A-Z])(?=.*[0-9])))(?=.{6,})");The expression is nearly the same as the strong condition, except this time we�re including an or condition. We essentially want to label a password as having medium strength if it contains six characters or more and has at least one lowercase and one uppercase alphabetical character or has at least one lowercase and one numeric character or has at least one uppercase and one numeric character.

We�ve chosen to leave special characters out of this one.Finally we need a way to track input on the input field. This will be handled through AngularJS by using the ngChange directive. By placing ng-change="analyze(password)" in the input tag it will call the analyze(value) method every time a key-stroke happens.

That�s when we call our RegEx validators.Here is the full code if you�d like to see it all put together:

Instead of Recently one of my Twitter followers asked me how they might validate password strength using regular expressions (RegEx) in their code.Regular expressions via Wikipedia:A sequence of characters that forms a search pattern, mainly for use in pattern matching with strings, or string matching.RegEx is nice because you can accomplish a whole lot with very little.

In this case we are going to check various aspects of a string and see if it meets our requirements, being a strong or medium strength password. In this example, I�m going to use a mixture of AngularJS and vanilla JavaScript.

Basically, the JavaScript will do all the heavy lifting and the AngularJS code will be responsible for binding it all to the screen.To show the password strength to the user, we�re going to use a rectangle that contains a color.

We�ll say that a red rectangle holds a weak password, orange medium, and green a strong password. The HTML behind this would look something like the following: The above code has an input box and a rectangular div tag. There is, however, a few pieces of AngularJS code that we�ll see in a moment.The passwordStrength variable that you see in the ng-style tag password strength regex all the styling information for the strength rectangle.

The style information we�re going to use is as follows: } ;Moving beyond the basic AngularJS stuff, lets get down to the good stuff. We�re going to make use of two different RegEx validation strings. One string will represent what is required for creating a strong password and the other will represent what is necessary for creating a medium strength password.

If neither expressions are satisfied, we�ll assume it is poor strength. var strongRegex = new RegExp ( "^(?=.*[a-z])(?=.*[A-Z])(?=.*[0-9])(?=.*[!@#$%^&*])(?=.{8,})" ) ;Above you can see the expression for validating a strong password. Let�s break down what it is doing. RegExDescription^The password string will start this way(?=.*[a-z])The string must contain at least 1 lowercase alphabetical character(?=.*[A-Z])The string must contain at least 1 uppercase alphabetical character(?=.*[0-9])The string must contain at least 1 numeric character(?=.*[!@#$%^&*])The string must contain at least one special character, but we are escaping reserved RegEx characters to avoid conflict(?=.{8,})The string must be eight characters or longerThat wasn�t so bad!

So how about our medium strength validator? There is less precision in this one, thus making it necessary to create a more complex regular expression. var mediumRegex = new RegExp ( "^(((?=.*[a-z])(?=.*[A-Z]))|((?=.*[a-z])(?=.*[0-9]))|((?=.*[A-Z])(?=.*[0-9])))(?=.{6,})" ) ;The expression is nearly the same as the strong condition, except this time we�re including an or condition.

We essentially want to label a password as having medium strength if it contains six characters or more and has at least one lowercase and one uppercase alphabetical character or has at least one lowercase and one numeric character or has at least one uppercase and one numeric character.

We�ve chosen to leave special characters out of this one.Finally we need a way to track input on the input field. This will be handled through AngularJS by using the ngChange directive. By placing ng-change="analyze(password)" in the input tag it will call the analyze(value) method every time a key-stroke happens. That�s when we call our RegEx validators.Here is the full code if you�d like to see it all put together: < / html >ConclusionRegular expressions are quite powerful and if you can master them, they will save you a ton of coding time.

Instead of parsing through the string using tokens or some other nonsense we managed to validate our string using a single line of code. Nic RaboyNic is a skilled application developer who has released several native and hybrid mobile applications to iTunes and Google Play.

He writes about his development experiences related to making web and mobile app development easier to understand and has experience in Android, Node.js, Apache Cordova, Java, NoSQL, SQL, GoLang, NativeScript, and Unity3D. Hello Nic,Nice blog! I am editor at Web Code Geeks (www.webcodegeeks.com). We have the WCG program (see https://www.webcodegeeks.com/join-us/wcg/), that I think you�d be perfect for.If you�re interested, send me an email to [email�protected]and we can discuss further.Best regards,Drosopoulou Eleftheria� Reset Password Recent Posts� Record IP Camera Surveillance Video With A Raspberry Pi� TPDP Episode #9: An Ember In The Land Of Web Frameworks� Use Mozilla�s LocalForage For Key-Value Storage In Ionic Framework� Build A Time-Based One-Time Password Manager With Ionic 2� Three Simple Ways To Get Online With A Raspberry Pi Zero IoT DeviceSubscribe on YouTube Welcome to my code blog!

My name is Nic Raboy and I love to fiddle with code and new technology. Here you'll find tutorials regarding mobile application development, web application development, and game development. It doesn't end there. Anything I f