feat(apple): gamepad ui

clients/apple/Sources/PunktfunkKit/ClientTLS.swift

@@ -4,10 +4,16 @@
 //
 // To present that identity, URLSession needs a SecIdentity (cert + private key pair). The client
 // stores its identity as PEM (rcgen ECDSA P-256, PKCS#8 key). We rebuild a SecIdentity natively:
-// CryptoKit parses the key → its X9.63 form → a SecKey, the cert PEM → a SecCertificate, and
-// SecIdentityCreateWithCertificate pairs them via the Keychain. This is macOS-only
-// (SecIdentityCreateWithCertificate is unavailable on iOS — that path will need a PKCS#12); the
-// client library is macOS-first today.
+// CryptoKit parses the key → its X9.63 form → a SecKey, the cert PEM → a SecCertificate. From
+// there the two platform families diverge because `SecIdentityCreateWithCertificate` — the
+// straight-line "pair these two" API — is macOS-only:
+//   - macOS: SecIdentityCreateWithCertificate does the pairing directly once the key is in the
+//     Keychain (a plain `SecItemAdd`).
+//   - iOS/tvOS: that API is unavailable. Instead, add BOTH the key and the certificate to the
+//     Keychain (under the same application tag) and query `kSecClassIdentity` — the system
+//     correlates a stored cert against a stored key with a matching public key and vends the pair
+//     as one `SecIdentity`, no PKCS#12 needed. This is the standard non-macOS technique for
+//     "I already have a raw cert + key, not a .p12".
 
 import CryptoKit
 import Foundation
@@ -18,15 +24,12 @@ private let tlsLog = Logger(subsystem: "io.unom.punktfunk", category: "library-t
 
 enum ClientTLS {
     enum TLSError: LocalizedError {
-        case unsupportedPlatform
         case badKey(String)
         case badCert
         case identity(String)
 
         var errorDescription: String? {
             switch self {
-            case .unsupportedPlatform:
-                return "Library mTLS is supported on macOS only right now."
             case .badKey(let why): return "Couldn't load the client key: \(why)"
             case .badCert: return "Couldn't load the client certificate."
             case .identity(let why): return "Couldn't build the client identity: \(why)"
@@ -45,9 +48,8 @@ enum ClientTLS {
     }
 
     /// Build a `SecIdentity` from the client's PEM cert + PKCS#8 P-256 key. Pairs them via the
-    /// Keychain (the key is stored once under a stable tag, so repeat calls reuse it).
+    /// Keychain (stored once under a stable tag, so repeat calls reuse it).
     static func makeIdentity(certPEM: String, keyPEM: String) throws -> SecIdentity {
-        #if os(macOS)
         // Key: CryptoKit accepts the SEC1 or PKCS#8 PEM; its x963 form is what SecKey wants.
         let priv: P256.Signing.PrivateKey
         do {
@@ -71,9 +73,11 @@ enum ClientTLS {
               let cert = SecCertificateCreateWithData(nil, certDER as CFData)
         else { throw TLSError.badCert }
 
+        let tag = Data("io.unom.punktfunk.library-client-key".utf8)
+
+        #if os(macOS)
         // The key must live in a Keychain for SecIdentityCreateWithCertificate to pair it with the
         // cert. Add it under a stable tag; a duplicate just means a previous fetch already did.
-        let tag = Data("io.unom.punktfunk.library-client-key".utf8)
         let add: [CFString: Any] = [
             kSecClass: kSecClassKey,
             kSecAttrApplicationTag: tag,
@@ -81,7 +85,7 @@ enum ClientTLS {
         ]
         let status = SecItemAdd(add as CFDictionary, nil)
         guard status == errSecSuccess || status == errSecDuplicateItem else {
-            throw TLSError.identity("keychain add failed (OSStatus \(status))")
+            throw TLSError.identity("keychain add key failed (OSStatus \(status))")
         }
 
         var identity: SecIdentity?
@@ -91,20 +95,64 @@ enum ClientTLS {
         }
         return identity
         #else
-        throw TLSError.unsupportedPlatform
+        // Add the key (tagged) and the certificate (matched to it by public key) separately —
+        // a duplicate of either just means a previous fetch already added it.
+        let addKey: [CFString: Any] = [
+            kSecClass: kSecClassKey,
+            kSecAttrApplicationTag: tag,
+            kSecValueRef: secKey,
+        ]
+        let keyStatus = SecItemAdd(addKey as CFDictionary, nil)
+        guard keyStatus == errSecSuccess || keyStatus == errSecDuplicateItem else {
+            throw TLSError.identity("keychain add key failed (OSStatus \(keyStatus))")
+        }
+
+        let addCert: [CFString: Any] = [
+            kSecClass: kSecClassCertificate,
+            kSecValueRef: cert,
+        ]
+        let certStatus = SecItemAdd(addCert as CFDictionary, nil)
+        guard certStatus == errSecSuccess || certStatus == errSecDuplicateItem else {
+            throw TLSError.identity("keychain add certificate failed (OSStatus \(certStatus))")
+        }
+
+        // The system correlates the just-added cert against the tagged key (matching public key)
+        // and vends the pair as a kSecClassIdentity — the tag filter here matches the KEY half.
+        var identityRef: CFTypeRef?
+        let query: [CFString: Any] = [
+            kSecClass: kSecClassIdentity,
+            kSecAttrApplicationTag: tag,
+            kSecReturnRef: true,
+        ]
+        let idStatus = SecItemCopyMatching(query as CFDictionary, &identityRef)
+        guard idStatus == errSecSuccess, let identityRef else {
+            throw TLSError.identity("SecItemCopyMatching(kSecClassIdentity) (OSStatus \(idStatus))")
+        }
+        // Safe: a kSecClassIdentity query with kSecReturnRef always vends a SecIdentity.
+        return (identityRef as! SecIdentity) // swiftlint:disable:this force_cast
         #endif
     }
 }
 
 /// URLSession delegate that pins the host's self-signed cert (by the fingerprint the client
-/// already trusts) and presents the client identity for the mTLS client-cert challenge.
+/// already trusts) and presents the client identity for the mTLS client-cert challenge — but ONLY
+/// for challenges from `host`:`port` (the punktfunk host itself). A session built with this
+/// delegate is safe to reuse for OTHER origins too (e.g. a GOG/Heroic/Xbox cover-art CDN): a
+/// non-matching origin falls through to `.performDefaultHandling`, i.e. normal system trust
+/// evaluation and no client cert — exactly what `URLSession.shared` would have done. Without the
+/// host scoping, pinning would reject every external origin's cert (its fingerprint never matches
+/// the host's) and the client identity would leak to servers that didn't ask for it.
 final class LibraryTLSDelegate: NSObject, URLSessionDelegate {
     private let identity: SecIdentity
     private let pinnedHostFingerprint: Data? // SHA-256 of the host cert DER; nil = accept any (TOFU)
+    private let host: String
+    private let port: Int
 
-    init(identity: SecIdentity, pinnedHostFingerprint: Data?) {
+    init(identity: SecIdentity, pinnedHostFingerprint: Data?, host: String, port: UInt16) {
         self.identity = identity
         self.pinnedHostFingerprint = pinnedHostFingerprint
+        self.host = host
+        self.port = Int(port)
     }
 
     func urlSession(
@@ -112,11 +160,16 @@ final class LibraryTLSDelegate: NSObject, URLSessionDelegate {
         didReceive challenge: URLAuthenticationChallenge,
         completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void
     ) {
-        switch challenge.protectionSpace.authenticationMethod {
+        let space = challenge.protectionSpace
+        guard space.host == host, space.port == port else {
+            completionHandler(.performDefaultHandling, nil)
+            return
+        }
+        switch space.authenticationMethod {
         case NSURLAuthenticationMethodServerTrust:
             // Pin the host cert by fingerprint — the host is self-signed (the client trusts it the
             // same way the QUIC session does). No pin yet (TOFU) → accept the presented leaf.
-            guard let trust = challenge.protectionSpace.serverTrust,
+            guard let trust = space.serverTrust,
                   let leaf = (SecTrustCopyCertificateChain(trust) as? [SecCertificate])?.first
             else {
                 completionHandler(.cancelAuthenticationChallenge, nil)