From 1ce48bc77e5bb86b217f55073e540f418386ef6f Mon Sep 17 00:00:00 2001
From: Shadowfacts <me@shadowfacts.net>
Date: Thu, 17 Jun 2021 22:58:46 -0400
Subject: [PATCH] Fix connecting to tx.decrypt.fail

---
 GeminiProtocol/GeminiProtocol.swift | 26 ++++++++++++++++++++------
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/GeminiProtocol/GeminiProtocol.swift b/GeminiProtocol/GeminiProtocol.swift
index 569b71f..649c508 100644
--- a/GeminiProtocol/GeminiProtocol.swift
+++ b/GeminiProtocol/GeminiProtocol.swift
@@ -14,6 +14,8 @@ class GeminiProtocol: NWProtocolFramerImplementation {
     
     private var tempStatusCode: GeminiResponseHeader.StatusCode?
     private var tempMeta: String?
+    private var lastAttemptedMetaLength: Int?
+    private var lastFoundCR = false
     
     required init(framer: NWProtocolFramer.Instance) {
     }
@@ -45,13 +47,21 @@ class GeminiProtocol: NWProtocolFramerImplementation {
             return 3
         }
         
-        var attemptedMetaLength: Int?
         if tempMeta == nil {
-            // Minimum length is 2 bytes, spec does not say meta string is required
-            _ = framer.parseInput(minimumIncompleteLength: 2, maximumLength: 1024 + 2) { (buffer, isComplete) -> Int in
+            let min: Int
+            // if we previously tried to get the meta but failed (because the <CR><LF> was not found,
+            // the minimum amount we need before trying to parse is at least 1 or 2 (depending on whether we found the <CR>) bytes more
+            if let lastAttemptedMetaLength = lastAttemptedMetaLength {
+                min = lastAttemptedMetaLength + (lastFoundCR ? 1 : 2)
+            } else {
+                // Minimum length is 2 bytes, spec does not say meta string is required
+                min = 2
+            }
+            _ = framer.parseInput(minimumIncompleteLength: min, maximumLength: 1024 + 2) { (buffer, isComplete) -> Int in
                 guard let buffer = buffer,
                       buffer.count >= 2 else { return 0 }
-                attemptedMetaLength = buffer.count
+                print("got count: \(buffer.count)")
+                self.lastAttemptedMetaLength = buffer.count
                 
                 let lastPossibleCRIndex = buffer.index(before: buffer.index(before: buffer.endIndex))
                 var index = buffer.startIndex
@@ -66,6 +76,10 @@ class GeminiProtocol: NWProtocolFramerImplementation {
                 }
                 
                 if !found {
+                    if buffer[index] == 13 {
+                        // if we found <CR>, but not <LF>, save that info so that next time we only wait for 1 more byte instead of 2
+                        self.lastFoundCR = true
+                    }
                     if buffer.count < 1026 {
                         return 0
                     } else {
@@ -78,8 +92,8 @@ class GeminiProtocol: NWProtocolFramerImplementation {
             }
         }
         guard let meta = tempMeta else {
-            if let attempted = attemptedMetaLength {
-                return attempted + 1
+            if let attempted = self.lastAttemptedMetaLength {
+                return attempted + (lastFoundCR ? 1 : 2)
             } else {
                 return 2
             }