Omit sensitive data from PUSH_REPLY log

Namely auth-token.

TunnelKit/Sources/Core/SessionProxy+PushReply.swift

@@ -161,7 +161,7 @@ extension SessionProxy {
 
     // XXX: parsing is very optimistic
     
-    struct PushReply: SessionReply {
+    struct PushReply: SessionReply, CustomStringConvertible {
         private enum Topology: String {
             case net30
             
@@ -170,6 +170,8 @@ extension SessionProxy {
             case subnet
         }
         
+        private static let prefix = "PUSH_REPLY,"
+        
         private static let topologyRegexp = try! NSRegularExpression(pattern: "topology (net30|p2p|subnet)", options: [])
         
         private static let ifconfigRegexp = try! NSRegularExpression(pattern: "ifconfig [\\d\\.]+ [\\d\\.]+", options: [])
@@ -190,6 +192,8 @@ extension SessionProxy {
 
         private static let cipherRegexp = try! NSRegularExpression(pattern: "cipher [^\\s]+", options: [])
         
+        private let original: String
+
         let ipv4: IPv4Settings?
         
         let ipv6: IPv6Settings?
@@ -203,9 +207,11 @@ extension SessionProxy {
         let cipher: SessionProxy.Cipher?
         
         init?(message: String) throws {
-            guard message.hasPrefix("PUSH_REPLY") else {
+            guard message.hasPrefix(PushReply.prefix) else {
                 return nil
             }
+            let prefixOffset = message.index(message.startIndex, offsetBy: PushReply.prefix.count)
+            original = String(message[prefixOffset..<message.endIndex])
 
             var optTopologyArguments: [String]?
             var optIfconfig4Arguments: [String]?
@@ -380,6 +386,19 @@ extension SessionProxy {
             self.peerId = peerId
             self.cipher = cipher
         }
+        
+        // MARK: CustomStringConvertible
+        
+        var description: String {
+            let stripped = NSMutableString(string: original)
+            PushReply.authTokenRegexp.replaceMatches(
+                in: stripped,
+                options: [],
+                range: NSMakeRange(0, stripped.length),
+                withTemplate: "auth-token"
+            )
+            return stripped as String
+        }
     }
 }
 

TunnelKit/Sources/Core/SessionProxy.swift

@@ -875,7 +875,9 @@ public class SessionProxy {
             return
         }
 
+        if CoreConfiguration.logsSensitiveData {
             log.debug("Received control message: \"\(message)\"")
+        }
         
         let reply: PushReply
         do {
@@ -883,6 +885,7 @@ public class SessionProxy {
                 return
             }
             reply = optionalReply
+            log.debug("Received PUSH_REPLY: \"\(reply)\"")
         } catch let e {
             deferStop(.shutdown, e)
             return