Add AUTH relay request and response

Sources/NostrSDK/EventKind.swift

@@ -72,7 +72,13 @@ public enum EventKind: RawRepresentable, CaseIterable, Codable, Equatable, Hasha
     ///
     /// See [NIP-51](https://github.com/nostr-protocol/nips/blob/master/51.md#standard-lists)
     case bookmarksList
-
+
+    /// This kind of event provides a way for clients to authenticate to relays by signing an ephemeral event.
+    /// This kind is not meant to be published or queried.
+    ///
+    /// See [NIP-42](https://github.com/nostr-protocol/nips/blob/master/42.md).
+    case authentication
+
     /// This kind of event is for long-form texxt content, generally referred to as "articles" or "blog posts".
     ///
     /// See [NIP-23](https://github.com/nostr-protocol/nips/blob/master/23.md).
@@ -112,6 +118,7 @@ public enum EventKind: RawRepresentable, CaseIterable, Codable, Equatable, Hasha
         .report,
         .muteList,
         .bookmarksList,
+        .authentication,
         .longformContent,
         .dateBasedCalendarEvent,
         .timeBasedCalendarEvent,
@@ -141,6 +148,7 @@ public enum EventKind: RawRepresentable, CaseIterable, Codable, Equatable, Hasha
         case .report:                 return 1984
         case .muteList:               return 10000
         case .bookmarksList:          return 10003
+        case .authentication:         return 22242
         case .longformContent:        return 30023
         case .dateBasedCalendarEvent: return 31922
         case .timeBasedCalendarEvent: return 31923
@@ -164,6 +172,7 @@ public enum EventKind: RawRepresentable, CaseIterable, Codable, Equatable, Hasha
         case .report:                 return ReportEvent.self
         case .muteList:               return MuteListEvent.self
         case .bookmarksList:          return BookmarksListEvent.self
+        case .authentication:         return AuthenticationEvent.self
         case .longformContent:        return LongformContentEvent.self
         case .dateBasedCalendarEvent: return DateBasedCalendarEvent.self
         case .timeBasedCalendarEvent: return TimeBasedCalendarEvent.self

Sources/NostrSDK/Events/AuthenticationEvent.swift

@@ -0,0 +1,55 @@
+//
+//  AuthenticationEvent.swift
+//
+//
+//  Created by Terry Yiu on 5/1/24.
+//
+
+import Foundation
+
+/// An event that provides a way for clients to authenticate to relays.
+/// This kind is not meant to be published or queried.
+///
+/// See [NIP-42](https://github.com/nostr-protocol/nips/blob/master/42.md).
+public final class AuthenticationEvent: NostrEvent, RelayProviding, RelayURLValidating {
+    public required init(from decoder: Decoder) throws {
+        try super.init(from: decoder)
+    }
+
+    @available(*, unavailable, message: "This initializer is unavailable for this class.")
+    override init(kind: EventKind, content: String, tags: [Tag] = [], createdAt: Int64 = Int64(Date.now.timeIntervalSince1970), signedBy keypair: Keypair) throws {
+        try super.init(kind: kind, content: content, tags: tags, createdAt: createdAt, signedBy: keypair)
+    }
+
+    init(content: String, tags: [Tag] = [], createdAt: Int64 = Int64(Date.now.timeIntervalSince1970), signedBy keypair: Keypair) throws {
+        try super.init(kind: .authentication, content: content, tags: tags, createdAt: createdAt, signedBy: keypair)
+    }
+
+    /// The relay URL where this event authenticates to it.
+    public var relayURL: URL? {
+        guard let relayURLString = firstValueForRawTagName("relay") else {
+            return nil
+        }
+
+        return try? validateRelayURLString(relayURLString)
+    }
+
+    /// The challenge string as received from the relay.
+    public var challenge: String? {
+        firstValueForRawTagName("challenge")
+    }
+}
+
+public extension EventCreating {
+
+    func authenticate(relayURL: URL, challenge: String, signedBy keypair: Keypair) throws -> AuthenticationEvent {
+        let validatedRelayURL = try RelayURLValidator.shared.validateRelayURL(relayURL)
+
+        let tags: [Tag] = [
+            Tag(name: "relay", value: validatedRelayURL.absoluteString),
+            Tag(name: "challenge", value: challenge)
+        ]
+
+        return try AuthenticationEvent(content: "", tags: tags, signedBy: keypair)
+    }
+}

Sources/NostrSDK/RelayRequest.swift

@@ -11,6 +11,7 @@ enum RelayRequest {
     case event(NostrEvent)
     case request(subscriptionId: String, filter: Filter)
     case close(subscriptionId: String)
+    case auth(AuthenticationEvent)
     case count(subscriptionId: String, filter: Filter)
 
     var encoded: String? {
@@ -22,6 +23,8 @@ enum RelayRequest {
             payload = [AnyEncodable("REQ"), AnyEncodable(subscriptionId), AnyEncodable(filter)]
         case .close(let subscriptionId):
             payload = [AnyEncodable("CLOSE"), AnyEncodable(subscriptionId)]
+        case .auth(let event):
+            payload = [AnyEncodable("AUTH"), AnyEncodable(event)]
         case .count(let subscriptionId, let filter):
             payload = [AnyEncodable("COUNT"), AnyEncodable(subscriptionId), AnyEncodable(filter)]
         }

Sources/NostrSDK/RelayResponse.swift

@@ -67,6 +67,8 @@ enum RelayResponse: Decodable {
         case rateLimited = "rate-limited"
         case invalid
         case error
+        case authRequired = "auth-required"
+        case restricted
     }
 
     case event(subscriptionId: String, event: NostrEvent)

Tests/NostrSDKTests/Events/AuthenticationEventTests.swift

@@ -0,0 +1,41 @@
+//
+//  AuthenticationEventTests.swift
+//
+//
+//  Created by Terry Yiu on 5/2/24.
+//
+
+@testable import NostrSDK
+import XCTest
+
+final class AuthenticationEventTests: XCTestCase, EventCreating, EventVerifying, FixtureLoading {
+
+    func testCreateAuthenticationEvent() throws {
+        let relayURL = try XCTUnwrap(URL(string: "wss://relay.example.com/"))
+        let event = try authenticate(relayURL: relayURL, challenge: "some-challenge-string", signedBy: Keypair.test)
+
+        XCTAssertEqual(event.kind, .authentication)
+        XCTAssertEqual(event.relayURL, relayURL)
+        XCTAssertEqual(event.challenge, "some-challenge-string")
+
+        try verifyEvent(event)
+    }
+
+    func testDecodeAuthenticationEvent() throws {
+        let event: AuthenticationEvent = try decodeFixture(filename: "authentication_event")
+
+        XCTAssertEqual(event.id, "adb599bc2f6b4cf97d927de2cb36829326c86013e0a6e8f51159f80938a5c246")
+        XCTAssertEqual(event.pubkey, "9947f9659dd80c3682402b612f5447e28249997fb3709500c32a585eb0977340")
+        XCTAssertEqual(event.createdAt, 1714625219)
+        XCTAssertEqual(event.kind, .authentication)
+
+        let expectedTags: [Tag] = [
+            Tag(name: "relay", value: "wss://relay.example.com/"),
+            Tag(name: "challenge", value: "some-challenge-string")
+        ]
+        XCTAssertEqual(event.tags, expectedTags)
+        XCTAssertEqual(event.content, "")
+        XCTAssertEqual(event.signature, "b27181e0b72872c463ac75ebf3ad2c2502696d81551bbae6b2a391c67614daf2e321eb5ab724b04520b26fcf7a4c9823fefdb47b10d66c088db44162ba9c1291")
+    }
+
+}

Tests/NostrSDKTests/Fixtures/auth_request.json

@@ -0,0 +1 @@
+["AUTH",{"id":"adb599bc2f6b4cf97d927de2cb36829326c86013e0a6e8f51159f80938a5c246","pubkey":"9947f9659dd80c3682402b612f5447e28249997fb3709500c32a585eb0977340","created_at":1714625219,"kind":22242,"tags":[["relay","wss://relay.example.com/"],["challenge","some-challenge-string"]],"content":"","sig":"b27181e0b72872c463ac75ebf3ad2c2502696d81551bbae6b2a391c67614daf2e321eb5ab724b04520b26fcf7a4c9823fefdb47b10d66c088db44162ba9c1291"}]

Tests/NostrSDKTests/Fixtures/authentication_event.json

@@ -0,0 +1,12 @@
+{
+  "id": "adb599bc2f6b4cf97d927de2cb36829326c86013e0a6e8f51159f80938a5c246",
+  "pubkey": "9947f9659dd80c3682402b612f5447e28249997fb3709500c32a585eb0977340",
+  "created_at": 1714625219,
+  "kind": 22242,
+  "tags": [
+    ["relay", "wss://relay.example.com/"],
+    ["challenge", "some-challenge-string"]
+  ],
+  "content": "",
+  "sig": "b27181e0b72872c463ac75ebf3ad2c2502696d81551bbae6b2a391c67614daf2e321eb5ab724b04520b26fcf7a4c9823fefdb47b10d66c088db44162ba9c1291"
+}

Tests/NostrSDKTests/RelayRequestEncodingTests.swift

@@ -8,7 +8,7 @@
 @testable import NostrSDK
 import XCTest
 
-final class RelayRequestEncodingTests: XCTestCase, FixtureLoading, JSONTesting {
+final class RelayRequestEncodingTests: XCTestCase, EventCreating, FixtureLoading, JSONTesting {
 
     func testEncodeEvent() throws {
         let eventTag = Tag.event("93930d65435d49db723499335473920795e7f13c45600dcfad922135cf44bd63")
@@ -50,6 +50,14 @@ final class RelayRequestEncodingTests: XCTestCase, FixtureLoading, JSONTesting {
         XCTAssertEqual(request.encoded, expected)
     }
 
+    func testEncodeAuth() throws {
+        let authenticationEvent: AuthenticationEvent = try decodeFixture(filename: "authentication_event")
+        let request = try XCTUnwrap(RelayRequest.auth(authenticationEvent))
+        let expected = try loadFixtureString("auth_request")
+
+        XCTAssertTrue(areEquivalentJSONArrayStrings(request.encoded, expected))
+    }
+
     func testEncodeCount() throws {
         let filter = Filter(ids: nil,
                             authors: ["some-pubkey"],