Regex expression for complex password setting angular 8

Question

I tried this expression -

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

This regex will enforce these rules:

At least one upper case English letter, (?=.*?[A-Z])

At least one lower case English letter, (?=.*?[a-z])

At least one digit, (?=.*?[0-9])

At least one special character, (?=.*?[#?!@$%^&*-])

Minimum eight in length .{8,} (with the anchors)

How will be the regular expression for below requirement.

• Passwords that are 13 characters or longer only require lower case letters
• Passwords must contain at least 8 characters
• Passwords between 8 and 13 characters require at least 3 of the following 4 categories of characters:
  • Uppercase letters
  • Lowercase letters
  • Numbers
  • Symbols

Answer 1

While a single regex may not be the most readable / sane way to do this, it's actually rather straightforward:

^(?=.*?[a-z])(.{13,}|(?=.*?[A-Z])(?=.*?[0-9])(?=.*?[#?!@$%^&*-]).{8,12})$

I've simply added an alteration on the length so that 13+ chars merely requires [a-z] while 8-12 chars (one could omit the upper bound due to ordering) requires the full monty.