Android / Linux Support

Package.swift

@@ -17,16 +17,23 @@ let package = Package(
             name: "OAuthKit",
             targets: ["OAuthKit"])
     ],
+    dependencies: [
+        // Android / Linux Dependencies
+        .package(url: "https://github.com/apple/swift-crypto", from: .init(4, 5, 0))
+    ],
     targets: [
         .target(
             name: "OAuthKit",
+            dependencies: [
+                .product(name: "Crypto",
+                         package: "swift-crypto",
+                         condition: .when(platforms: [.android, .linux])
+                )
+            ],
             linkerSettings: [
-                .linkedFramework("CryptoKit"),
-                .linkedFramework("LocalAuthentication", .when(
-                    platforms: [.iOS]
-                )),
-                .linkedFramework("Network"),
-                .linkedFramework("Security")
+                .linkedFramework("LocalAuthentication",
+                    .when(platforms: [.iOS])
+                ),
             ]
         ),
         .testTarget(

README.md

@@ -40,7 +40,7 @@ OAuthKit can be installed using [Swift Package Manager](https://www.swift.org/do
 
 ```swift
 dependencies: [
-    .package(url: "https://github.com/codefiesta/OAuthKit", from: "2.1.1")
+    .package(url: "https://github.com/codefiesta/OAuthKit", from: "2.2.0")
 ]
 ```
 
@@ -315,3 +315,8 @@ OAuthKit should work with any standard OAuth2 provider. Below is a list of teste
 
 You can find the complete Swift DocC documentation for the [OAuthKit Framework here](https://codefiesta.github.io/OAuthKit/documentation/oauthkit/).
 
+
+## Linux / Android Support
+
+As of version [2.2.0](https://github.com/codefiesta/OAuthKit/releases/tag/2.2.0) OAuthKit will now compile for both [Android and Linux](https://www.swift.org/documentation/articles/swift-sdk-for-android-getting-started.html). However, secure storage still needs to be implemented for both [Android](https://github.com/codefiesta/OAuthKit/issues/153) and [Linux](https://github.com/codefiesta/OAuthKit/issues/152).
+

Sources/OAuthKit/Extensions/Data+Extensions.swift

@@ -5,7 +5,11 @@
 //  Created by Kevin McKee
 //
 
+#if canImport(CryptoKit)
 import CryptoKit
+#else
+import Crypto
+#endif
 import Foundation
 
 extension Data {
@@ -43,7 +47,16 @@ extension Data {
     /// - Returns: an array of cryptographically secure random bytes
     static func secureRandom(count: Int = 32) -> Data {
         var bytes = [UInt8](repeating: 0, count: count)
+        #if canImport(CryptoKit)
+        // Apple
         _ = SecRandomCopyBytes(kSecRandomDefault, bytes.count, &bytes)
+        #else
+        // Android / Linux
+        var generator = SystemRandomNumberGenerator()
+        for i in 0..<count {
+            bytes[i] = UInt8.random(in: 0...255, using: &generator)
+        }
+        #endif
         return Data(bytes: &bytes, count: bytes.count)
     }
 }

Sources/OAuthKit/Extensions/Digest+Extensions.swift

@@ -5,7 +5,11 @@
 //  Created by Kevin McKee
 //
 
+#if canImport(CryptoKit)
 import CryptoKit
+#else
+import Crypto
+#endif
 import Foundation
 
 extension Digest {

Sources/OAuthKit/Extensions/EnvironmentValues+Extensions.swift

@@ -4,7 +4,7 @@
 //
 //  Created by Kevin McKee
 //
-
+#if canImport(SwiftUI)
 import SwiftUI
 
 public extension EnvironmentValues {
@@ -21,3 +21,4 @@ struct OAuthKey: @preconcurrency EnvironmentKey {
     /// The default OAuth instance that is loaded into the environment.
     @MainActor static let defaultValue: OAuth = .init(.main)
 }
+#endif

Sources/OAuthKit/Extensions/String+Extensions.swift

@@ -5,7 +5,11 @@
 //  Created by Kevin McKee
 //
 
+#if canImport(CryptoKit)
 import CryptoKit
+#else
+import Crypto
+#endif
 import Foundation
 
 extension String {

Sources/OAuthKit/Extensions/URL+Extensions.swift

@@ -5,7 +5,11 @@
 //  Created by Kevin McKee
 //
 
+#if canImport(CryptoKit)
 import CryptoKit
+#else
+import Crypto
+#endif
 import Foundation
 
 extension URL {

Sources/OAuthKit/Extensions/URLRequest+Extensions.swift

@@ -6,6 +6,9 @@
 //
 
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 
 private let authHeader = "Authorization"
 

Sources/OAuthKit/Extensions/URLResponse+Extensions.swift

@@ -6,6 +6,9 @@
 //
 
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 
 public extension URLResponse {
 

Sources/OAuthKit/Extensions/UUID+Extensions.swift

@@ -5,7 +5,11 @@
 //  Created by Kevin McKee
 //
 
+#if canImport(CryptoKit)
 import CryptoKit
+#else
+import Crypto
+#endif
 import Foundation
 
 extension UUID {

Sources/OAuthKit/Keychain/Keychain+Storage.swift

@@ -0,0 +1,183 @@
+//
+//  Keychain+Extensions.swift
+//  OAuthKit
+//
+//  Created by Kevin McKee on 8/19/26.
+//
+
+import Foundation
+#if canImport(Security)
+import Security
+#endif
+
+/// The default account  to use.
+private let defaultAccount = "oauthkit"
+/// The default token identifier suffix.
+private let tokenIdentifier = "oauth-token"
+
+extension Keychain {
+
+    // Provides the storage protocols used for storing sensitive data.
+    // The storage operations should all be wrapped in a locking
+    // mechanism to prevent any potential data races.
+    protocol Storage {
+
+        /// The owning account identifier.
+        /// - Parameter account: a key indicating the account owner. Ideally, use the application identifier for this value.
+        init(account: String)
+
+        /// The account owner of this keychain storage.
+        var account: String { get }
+
+        /// Returns a list of keys owned by this account.
+        var keys: [String] { get }
+
+        /// Sets the data for the specified key
+        /// - Parameters:
+        ///   - data: the data to store for the specified key
+        ///   - key: the key to use for the data
+        /// - Returns: true if able to set the data, otherwise false
+        func set(_ data: Data, for key: String) throws -> Bool
+
+        /// Fetches storeed data from the data store with the specified key.
+        /// - Parameter key: the keychain key
+        /// - Returns: the data for the specified key or nil if not found
+        func get(key: String) throws -> Data?
+
+        /// Deletes the value for the specified key.
+        /// - Parameter key: the key to delete
+        /// - Returns: true if able to delete from the storage, otherwise false
+        func delete(key: String) -> Bool
+
+        /// Clears all values and keys for the current account.
+        /// - Returns: true if values were cleared, otherwise false.
+        func clear() -> Bool
+
+        /// Builds the combined account key by prefixing the specified key with the account.
+        /// - Parameter key: the key to prefix.
+        /// - Returns: the unique account key to use
+        func accountKey(_ key: String) -> String
+    }
+
+    #if canImport(Security)
+    /// The default token storage used by Apple ecosystems.
+    struct DefaultStorage: Storage {
+
+        var account: String = defaultAccount
+
+        init(account: String) {
+            self.account = account
+        }
+
+        var keys: [String] {
+            var results = [String]()
+            let query: [String: Any] = [
+                kSecClass as String: kSecClassGenericPassword,
+                kSecReturnAttributes as String: true,
+                kSecMatchLimit as String: kSecMatchLimitAll
+            ]
+
+            var result: AnyObject?
+            let status = withUnsafeMutablePointer(to: &result) { pointer in
+                SecItemCopyMatching(query as CFDictionary, UnsafeMutablePointer(pointer))
+            }
+
+            guard status == noErr else { return results }
+
+            if let items = result as? [[String: Any]] {
+                for item in items {
+                    if let key = item[kSecAttrAccount as String] as? String {
+                        results.append(key)
+                    }
+                }
+            }
+            return results.filter{ $0.starts(with: account)}.sorted{ $0 < $1}
+        }
+
+        /// Sets the value for the specified key.
+        /// - Parameters:
+        ///   - value: the value to store
+        ///   - key: the key to use
+        /// - Returns: true if able to set the value, otherwise false
+        @discardableResult
+        func set(_ data: Data, for key: String) throws -> Bool {
+            assert(key.isNotEmpty, "❌ The keychain key cannot be empty.")
+
+            let account = accountKey(key)
+            delete(key: account)
+
+            let query: [String: Any] = [
+                kSecClass as String: kSecClassGenericPassword,
+                kSecAttrAccount as String: account,
+                kSecValueData as String: data
+            ]
+
+            let status = SecItemAdd(query as CFDictionary, nil)
+            return status == errSecSuccess
+        }
+
+        /// Fetches storeed data from the data store with the specified key.
+        /// - Parameter key: the keychain key
+        /// - Returns: the data for the specified key or nil if not found
+        func get(key: String) throws -> Data? {
+
+            let account = accountKey(key)
+
+            let query: [String: Any] = [
+                kSecClass as String: kSecClassGenericPassword,
+                kSecMatchLimit as String: kSecMatchLimitOne,
+                kSecAttrAccount as String: account,
+                kSecReturnData as String: true
+            ]
+
+            var result: AnyObject?
+            let status = withUnsafeMutablePointer(to: &result) { pointer in
+                SecItemCopyMatching(query as CFDictionary, UnsafeMutablePointer(pointer))
+            }
+
+            guard status == noErr, let data = result as? Data else {
+                return nil
+            }
+
+            return data
+        }
+
+        /// Clears all values and keys for the current account.
+        /// - Returns: true if values were cleared, otherwise false.
+        @discardableResult
+        func clear() -> Bool {
+
+            var results: [Bool] = []
+            for key in keys {
+                results.append(delete(key: key))
+            }
+
+            guard results.isNotEmpty else { return true }
+            return results.allSatisfy{ $0 == true }
+        }
+
+        /// Deletes the value for the specified key.
+        /// - Parameter key: the key to delete
+        /// - Returns: true if able to delete from the storage, otherwise false
+        @discardableResult
+        func delete(key: String) -> Bool {
+            let query: [String: Any] = [
+                kSecClass as String: kSecClassGenericPassword,
+                kSecAttrAccount as String: key
+            ]
+            let status = SecItemDelete(query as CFDictionary)
+            return status == noErr
+        }
+    }
+    #endif
+}
+
+extension Keychain.Storage {
+
+    /// Builds the combined account key by prefixing the specified key with the account.
+    /// - Parameter key: the key to prefix.
+    /// - Returns: the unique account key to use
+    func accountKey(_ key: String) -> String {
+        account + "." + key + "." + tokenIdentifier
+    }
+}