Refactor peerID - 1/n: Add PeerID + Tests (#688)

* Unify SHA256 hash and hex usages * Refactor `peerID` - 1/n: Add `PeerID` + Tests
2026-07-25 17:25:20 +00:00 · 2025-09-30 12:49:36 +02:00
parent 78fb3f1bf6
commit bf712a0610
2 changed files with 563 additions and 0 deletions
@@ -0,0 +1,177 @@
+//
+// PeerID.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import Foundation
+
+struct PeerID: Equatable, Hashable {
+    enum Prefix: String, CaseIterable {
+        /// When no prefix is provided
+        case empty = ""
+        /// `"mesh:"`
+        case mesh = "mesh:"
+        /// `"name:"`
+        case name = "name:"
+        /// `"noise:"` (+ 64 characters hex)
+        case noise = "noise:"
+        /// `"nostr_"` (+ 16 characters hex)
+        case geoDM = "nostr_"
+        /// `"nostr:"` (+ 8 characters hex)
+        case geoChat = "nostr:"
+    }
+    
+    let prefix: Prefix
+    
+    /// Returns the actual value without any prefix
+    let bare: String
+    
+    /// Returns the full `id` value by combining `(prefix + bare)`
+    var id: String { prefix.rawValue + bare }
+    
+    // Private so the callers have to go through a convenience init
+    private init(prefix: Prefix, bare: any StringProtocol) {
+        self.prefix = prefix
+        self.bare = String(bare)
+    }
+}
+
+// MARK: - Convenience Inits
+
+extension PeerID {
+    /// Convenience init to create GeoDM PeerID by appending `"nostr_"` to the first 16 characters of `pubKey`
+    init(nostr_ pubKey: String) {
+        self.init(prefix: .geoDM, bare: pubKey.prefix(TransportConfig.nostrConvKeyPrefixLength))
+    }
+    
+    /// Convenience init to create GeoChat PeerID by appending `"nostr:"` to the first 8 characters of `pubKey`
+    init(nostr pubKey: String) {
+        self.init(prefix: .geoChat, bare: pubKey.prefix(TransportConfig.nostrShortKeyDisplayLength))
+    }
+    
+    /// Convenience init to create PeerID from String/Substring by splitting it into prefix and bare parts
+    init(str: any StringProtocol) {
+        if let prefix = Prefix.allCases.first(where: { $0 != .empty && str.hasPrefix($0.rawValue) }) {
+            self.init(prefix: prefix, bare: String(str).dropFirst(prefix.rawValue.count))
+        } else {
+            self.init(prefix: .empty, bare: str)
+        }
+    }
+    
+    /// Convenience init to create PeerID by converting Data to String
+    init?(data: Data) {
+        guard let str = String(data: data, encoding: .utf8) else { return nil }
+        self.init(str: str)
+    }
+}
+
+// MARK: - Noise Public Key Helpers
+
+extension PeerID {
+    /// Derive the stable 16-hex peer ID from a Noise static public key
+    init(publicKey: Data) {
+        self.init(str: publicKey.sha256Fingerprint().prefix(16))
+    }
+    
+    /// Returns a 16-hex short peer ID derived from a 64-hex Noise public key if needed
+    func toShort() -> PeerID {
+        if let noiseKey {
+            return PeerID(publicKey: noiseKey)
+        }
+        return self
+    }
+}
+
+// MARK: - Codable
+
+extension PeerID: Codable {
+    init(from decoder: any Decoder) throws {
+        self.init(str: try decoder.singleValueContainer().decode(String.self))
+    }
+    
+    func encode(to encoder: any Encoder) throws {
+        var container = encoder.singleValueContainer()
+        try container.encode(id)
+    }
+}
+
+// MARK: - Helpers
+
+extension PeerID {
+    var isEmpty: Bool {
+        id.isEmpty
+    }
+    
+    /// Returns true if `id` starts with "`nostr:`"
+    var isGeoChat: Bool {
+        prefix == .geoChat
+    }
+    
+    /// Returns true if `id` starts with "`nostr_`"
+    var isGeoDM: Bool {
+        prefix == .geoDM
+    }
+    
+    func toPercentEncoded() -> String {
+        id.addingPercentEncoding(withAllowedCharacters: .urlPathAllowed) ?? id
+    }
+}
+
+// MARK: - Validation
+
+extension PeerID {
+    private enum Constants {
+        static let maxIDLength = 64
+        static let hexIDLength = 16 // 8 bytes = 16 hex chars
+    }
+    
+    /// Validates a peer ID from any source (short 16-hex, full 64-hex, or internal alnum/-/_ up to 64)
+    var isValid: Bool {
+        if prefix != .empty {
+            return PeerID(str: bare).isValid
+        }
+        
+        // Accept short routing IDs (exact 16-hex) or Full Noise key hex (exact 64-hex)
+        if isShort || isNoiseKeyHex {
+            return true
+        }
+        
+        // If length equals short or full but isn't valid hex, reject
+        if id.count == Constants.hexIDLength || id.count == Constants.maxIDLength {
+            return false
+        }
+        
+        // Internal format: alphanumeric + dash/underscore up to 63 (not 16 or 64)
+        let validCharset = CharacterSet.alphanumerics.union(CharacterSet(charactersIn: "-_"))
+        return !id.isEmpty &&
+                id.count < Constants.maxIDLength &&
+                id.rangeOfCharacter(from: validCharset.inverted) == nil
+    }
+    
+    /// Short routing IDs (exact 16-hex)
+    var isShort: Bool {
+        id.count == Constants.hexIDLength && Data(hexString: id) != nil
+    }
+    
+    /// Full Noise key hex (exact 64-hex)
+    var isNoiseKeyHex: Bool {
+        noiseKey != nil
+    }
+    
+    /// Full Noise key (exact 64-hex) as Data
+    var noiseKey: Data? {
+        guard id.count == Constants.maxIDLength else { return nil }
+        return Data(hexString: id)
+    }
+}
+
+// MARK: - Comparable
+
+extension PeerID: Comparable {
+    static func < (lhs: PeerID, rhs: PeerID) -> Bool {
+        lhs.id < rhs.id
+    }
+}