Merge pull request #76 from auth0/add-string-code-formata-otp

Allow to send custom NumberFormatter for otp

Author: hzalaz

Guardian/Enrollment/EnrolledDevice.swift

@@ -139,11 +139,11 @@ public struct OTPParameters: Codable {
         case period
     }
 
-    public init(base32Secret: String, algorithm: HMACAlgorithm = .sha1, digits: Int =  6, period: Int = 30) {
+    public init(base32Secret: String, algorithm: HMACAlgorithm? = nil, digits: Int? = nil, period: Int? = nil) {
         self.base32Secret = base32Secret
-        self.algorithm = algorithm
-        self.digits = digits
-        self.period = period
+        self.algorithm = algorithm ?? .sha1
+        self.digits = digits ?? 6
+        self.period = period ?? 30
     }
 
 }

Guardian/Generators/OneTimePasswordGenerator.swift

@@ -23,13 +23,13 @@
 import Foundation
 
 public protocol TOTP {
-    func stringCode(time: TimeInterval) -> String
+    func stringCode(time: TimeInterval, formatter: NumberFormatter?) -> String
     func code(time: TimeInterval) -> Int
 }
 
-extension TOTP {
-    public func stringCode() -> String {
-        return self.stringCode(time: Date().timeIntervalSince1970)
+public extension TOTP {
+    public func stringCode(time: TimeInterval = Date().timeIntervalSince1970, formatter: NumberFormatter? = nil) -> String {
+        return self.stringCode(time: time, formatter: formatter)
     }
 
     public func code() -> Int {
@@ -38,7 +38,7 @@ extension TOTP {
 }
 
 public protocol HOTP {
-    func stringCode(counter: Int) -> String
+    func stringCode(counter: Int, formatter: NumberFormatter?) -> String
     func code(counter: Int) -> Int
 }
 
@@ -96,27 +96,29 @@ struct OneTimePasswordGenerator: TOTP, HOTP {
         return Int(hash)
     }
 
-    func stringCode(counter: Int) -> String {
+    func stringCode(counter: Int, formatter: NumberFormatter? = nil) -> String {
         let code = self.code(counter: counter)
-        return format(code: code, digits: self.parameters.digits)
+        return format(code: code, digits: self.parameters.digits, formatter: formatter)
     }
 
     func code(time: TimeInterval) -> Int {
         let steps = timeSteps(from: time, period: self.parameters.period)
         return self.code(counter: steps)
     }
 
-    func stringCode(time: TimeInterval) -> String {
+    func stringCode(time: TimeInterval, formatter: NumberFormatter? = nil) -> String {
         let steps = timeSteps(from: time, period: self.parameters.period)
         let code = self.code(counter: steps)
-        return format(code: code, digits: self.parameters.digits)
+        return format(code: code, digits: self.parameters.digits, formatter: formatter)
     }
 
     private func timeSteps(from time: TimeInterval, period: Int) -> Int {
         return Int(time / Double(self.parameters.period))
     }
 
-    private func format(code: Int, digits: Int) -> String {
-        return String(format: "%0\(digits)d", code)
+    private func format(code: Int, digits: Int, formatter: NumberFormatter?) -> String {
+        let defaultFormatted = String(format: "%0\(digits)d", code)
+        guard let formatter = formatter else { return defaultFormatted }
+        return formatter.string(from: NSNumber(value: code)) ?? defaultFormatted
     }
 }

GuardianTests/Generators/OneTimePasswordGeneratorSpec.swift

@@ -69,6 +69,16 @@ class OneTimePasswordGeneratorSpec: QuickSpec {
                     expect(otp.stringCode(time: 49)).to(equal(otp.code(time: 49).description)) // Picked time that generates a number with 6 digits and no 0 prefix in string
                 }
 
+                it("should allow custom format for string code") {
+                    let formatter = NumberFormatter()
+                    formatter.usesGroupingSeparator = true
+                    formatter.groupingSeparator = " "
+                    formatter.groupingSize = 3
+                    formatter.minimumIntegerDigits = 6
+                    formatter.paddingCharacter = "0"
+                    expect(otp.stringCode(time: 49, formatter: formatter)).to(equal("287 082"))
+                }
+
                 context("sha1") {
                     let key = "GEZDGNBVGY3TQOJQGEZDGNBVGY3TQOJQ"
                     let alg = HMACAlgorithm.sha1
@@ -121,10 +131,21 @@ class OneTimePasswordGeneratorSpec: QuickSpec {
                     }
 
                     it("should return code '\(code)' for counter '\(counter)'") {
-                        expect(otp.stringCode(counter: counter)).to(equal(code))
+                        expect(otp.stringCode(counter: counter, formatter: nil)).to(equal(code))
                     }
                 }
 
+                it("should allow custom format for string code") {
+                    let formatter = NumberFormatter()
+                    formatter.usesGroupingSeparator = true
+                    formatter.groupingSeparator = " "
+                    formatter.groupingSize = 3
+                    formatter.minimumIntegerDigits = 6
+                    formatter.paddingCharacter = "0"
+                    let otp = try! Guardian.hotp(base32Secret: "GEZDGNBVGY3TQOJQGEZDGNBVGY3TQOJQ", algorithm: .sha1, digits: 6)
+                    expect(otp.stringCode(counter: 0, formatter: formatter)).to(equal("755 224"))
+                }
+
                 context("sha1") {
                     let key = "GEZDGNBVGY3TQOJQGEZDGNBVGY3TQOJQ" // Base32.encode("12345678901234567890")
                     let alg = HMACAlgorithm.sha1