Add logic for more customizable password generator

2020-02-28 19:04:53 +01:00 · 2020-02-28 19:04:53 +01:00 · ff014a5699
commit ff014a5699
parent 49a371d495
10 changed files with 352 additions and 131 deletions
--- a/passKit/Passwords/PasswordGenerator.swift
+++ b/passKit/Passwords/PasswordGenerator.swift
@ -0,0 +1,121 @@
+//
+//  PasswordGenerator.swift
+//  passKit
+//
+//  Created by Danny Moesch on 27.02.20.
+//  Copyright © 2020 Bob Sun. All rights reserved.
+//
+
+public struct PasswordGenerator: Codable {
+
+    private static let digits = "0123456789"
+    private static let letters = "abcdefghijklmnopqrstuvwxyz"
+    private static let capitalLetters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+    private static let specialSymbols = "!\"#$%&'()*+,./:;<=>?@[\\]^_`{|}~"
+
+    private static let words: [String] = {
+        let bundle = Bundle(identifier: Globals.passKitBundleIdentifier)!
+        return ["eff_long_wordlist", "eff_short_wordlist"]
+            .map { name -> String in
+                guard let asset = NSDataAsset(name: name, bundle: bundle),
+                    let data = String(data: asset.data, encoding: .utf8) else {
+                    return ""
+                }
+                return data
+            }
+            .joined(separator: "\n")
+            .splitByNewline()
+    }()
+
+    public var flavor = PasswordGeneratorFlavor.random
+    public var length = 15
+    public var varyCases = true
+    public var useDigits = true
+    public var useSpecialSymbols = true
+    public var groups = 4
+
+    public var limitedLength: Int {
+        let lengthLimits = flavor.lengthLimits
+        return max(lengthLimits.min, min(lengthLimits.max, length))
+    }
+
+    private var characters: String {
+        var characters = Self.letters
+        if varyCases {
+            characters.append(Self.capitalLetters)
+        }
+        if useDigits {
+            characters.append(Self.digits)
+        }
+        if useSpecialSymbols {
+            characters.append(Self.specialSymbols)
+        }
+        return characters
+    }
+
+    private var delimiters: String {
+        var delimiters = ""
+        if useDigits {
+            delimiters.append(Self.digits)
+        }
+        if useSpecialSymbols {
+            delimiters.append(Self.specialSymbols)
+        }
+        return delimiters
+    }
+
+    public func generate() -> String {
+        switch flavor {
+        case .random:
+            return generateRandom()
+        case .xkcd:
+            return generateXkcd()
+        }
+    }
+
+    public func isAcceptable(groups: Int) -> Bool {
+        guard flavor == .random, groups > 0, groups < length else {
+            return false
+        }
+        return (length + 1) % groups == 0
+    }
+
+    private func generateRandom() -> String {
+        let currentCharacters = characters
+        if groups > 1, isAcceptable(groups: groups) {
+            return selectRandomly(count: length - groups + 1, from: currentCharacters)
+                .slices(count: UInt(groups))
+                .map { String($0) }
+                .joined(separator: "-")
+        }
+        return String(selectRandomly(count: length, from: currentCharacters))
+    }
+
+    private func generateXkcd() -> String {
+        let currentDelimiters = delimiters
+        return getRandomDelimiter(from: currentDelimiters) + (0 ..< length)
+            .map { _ in getRandomWord() + getRandomDelimiter(from: currentDelimiters) }
+            .joined()
+    }
+
+    private func getRandomDelimiter(from delimiters: String) -> String {
+        if delimiters.isEmpty {
+            return ""
+        }
+        return String(delimiters.randomElement()!)
+    }
+
+    private func getRandomWord() -> String {
+        let word = Self.words.randomElement()!
+        if varyCases, Bool.random() {
+            return word.uppercased()
+        }
+        return word
+    }
+
+    private func selectRandomly(count: Int, from string: String) -> [Character] {
+        return (0 ..< count).map { _ in string.randomElement()! }
+    }
+}
+
+extension PasswordGeneratorFlavor: Codable {}