Add base64url Data extensions

BitwardenKit/Core/Platform/Extensions/Data.swift

@@ -2,6 +2,28 @@ import CryptoKit
 import Foundation
 
 public extension Data {
+    // MARK: Initializers
+    
+    /// Parses bytes from a base64url-encoded string.
+    init?(base64UrlEncoded str: String) throws {
+        // .ignoreUnknownCharacters allows unpadded strings as a side-effect.
+        try self.init(base64Encoded: str.urlDecoded(), options: .ignoreUnknownCharacters)
+    }
+    
+    // MARK: Functions
+    
+    /// Encodes bytes in Data as a base64url string.
+    func base64UrlEncodedString(trimPadding shouldTrim: Bool) -> String {
+        let encoded = base64EncodedString()
+            .replacingOccurrences(of: "+", with: "-")
+            .replacingOccurrences(of: "/", with: "_")
+        if shouldTrim {
+            return encoded.trimmingCharacters(in: CharacterSet(["="]))
+        } else {
+            return encoded
+        }
+    }
+    
     /// Generates a hash value for the provided data.
     ///
     /// - Parameter using: The type of cryptographically secure hashing being performed.

BitwardenKit/Core/Platform/Extensions/DataTests.swift

@@ -13,4 +13,36 @@ class DataTests: BitwardenTestCase {
             "0101010101010101010101010101010101010101010101010101010101010101",
         )
     }
+    
+    func test_asBase64UrlStringPadded() {
+        let subject = Data(repeating: 1, count: 32)
+        XCTAssertEqual(
+            subject.base64UrlEncodedString(trimPadding: false),
+            "AQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQE=",
+        )
+    }
+    
+    func test_asBase64UrlStringUnpadded() {
+        let subject = Data(repeating: 1, count: 32)
+        XCTAssertEqual(
+            subject.base64UrlEncodedString(trimPadding: false),
+            "AQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQE",
+        )
+    }
+
+    func test_fromBase64UrlStringPadded() {
+        let subject = "9031WCEDOh6ZUGV_-wvUSw=="
+        XCTAssertEqual(
+            Data(base64UrlEncoded: subject)!,
+            Data([0xf7, 0x4d, 0xf5, 0x58, 0x21, 0x03, 0x3a, 0x1e, 0x99, 0x50, 0x65, 0x7f, 0xfb, 0x0b, 0xd4, 0x4b]),
+        )
+    }
+    
+    func test_fromBase64UrlStringUnpadded() {
+        let subject = "9031WCEDOh6ZUGV_-wvUSw"
+        XCTAssertEqual(
+            Data(base64UrlEncoded: subject)!,
+            Data([0xf7, 0x4d, 0xf5, 0x58, 0x21, 0x03, 0x3a, 0x1e, 0x99, 0x50, 0x65, 0x7f, 0xfb, 0x0b, 0xd4, 0x4b]),
+        )
+    }
 }