initial commit

ios_client/EncryptedChat/Utilities/Extensions.swift

@@ -0,0 +1,132 @@
+import Foundation
+import CryptoKit
+
+// MARK: - Data ↔ Hex
+
+extension Data {
+    /// Convert data to lowercase hex string
+    var hexString: String {
+        map { String(format: "%02x", $0) }.joined()
+    }
+
+    /// Initialize Data from a hex string
+    init?(hexString: String) {
+        let hex = hexString.lowercased()
+        guard hex.count % 2 == 0 else { return nil }
+        var data = Data(capacity: hex.count / 2)
+        var index = hex.startIndex
+        while index < hex.endIndex {
+            let nextIndex = hex.index(index, offsetBy: 2)
+            guard let byte = UInt8(hex[index..<nextIndex], radix: 16) else { return nil }
+            data.append(byte)
+            index = nextIndex
+        }
+        self = data
+    }
+
+    /// Generate random bytes
+    static func randomBytes(_ count: Int) -> Data {
+        var data = Data(count: count)
+        data.withUnsafeMutableBytes { ptr in
+            _ = SecRandomCopyBytes(kSecRandomDefault, count, ptr.baseAddress!)
+        }
+        return data
+    }
+}
+
+// MARK: - Data ↔ Base64 (Protocol Wire Format)
+
+extension Data {
+    /// Encode to standard base64 string (matching Python's base64.b64encode)
+    func base64EncodedString() -> String {
+        self.base64EncodedString(options: [])
+    }
+
+    /// Decode from base64 string
+    static func fromBase64(_ string: String) throws -> Data {
+        // Try standard base64 first, then URL-safe
+        if let data = Data(base64Encoded: string, options: .ignoreUnknownCharacters) {
+            return data
+        }
+        throw CryptoError.invalidBase64
+    }
+}
+
+// MARK: - UInt32 Big-Endian
+
+extension UInt32 {
+    var bigEndianData: Data {
+        var value = self.bigEndian
+        return Data(bytes: &value, count: 4)
+    }
+}
+
+// MARK: - CryptoKit Key → Data
+
+extension Curve25519.KeyAgreement.PublicKey {
+    var rawData: Data {
+        Data(rawRepresentation)
+    }
+}
+
+extension Curve25519.KeyAgreement.PrivateKey {
+    var rawData: Data {
+        Data(rawRepresentation)
+    }
+}
+
+extension Curve25519.Signing.PublicKey {
+    var rawData: Data {
+        Data(rawRepresentation)
+    }
+}
+
+extension Curve25519.Signing.PrivateKey {
+    var rawData: Data {
+        Data(rawRepresentation)
+    }
+}
+
+// MARK: - String helpers
+
+extension String {
+    /// Trim whitespace and newlines
+    var trimmed: String {
+        trimmingCharacters(in: .whitespacesAndNewlines)
+    }
+}
+
+// MARK: - Dictionary merge helper
+
+extension Dictionary where Key == String, Value == Any {
+    func string(for key: String) -> String? {
+        self[key] as? String
+    }
+
+    func int(for key: String) -> Int? {
+        if let i = self[key] as? Int { return i }
+        if let s = self[key] as? String, let i = Int(s) { return i }
+        return nil
+    }
+
+    func dict(for key: String) -> [String: Any]? {
+        self[key] as? [String: Any]
+    }
+
+    func array(for key: String) -> [[String: Any]]? {
+        self[key] as? [[String: Any]]
+    }
+
+    func data(for key: String) -> Data? {
+        if let hex = self[key] as? String {
+            return Data(hexString: hex)
+        }
+        return nil
+    }
+
+    func bool(for key: String) -> Bool? {
+        if let b = self[key] as? Bool { return b }
+        if let i = self[key] as? Int { return i != 0 }
+        return nil
+    }
+}