From ee608ad0c87b7fb34a2d43d711fd78b5f44d2689 Mon Sep 17 00:00:00 2001
From: WolverinDEV <git@mcgalaxy.de>
Date: Fri, 22 Nov 2019 00:09:27 +0100
Subject: [PATCH] Implemented the letsencrypt challange

---
 server/src/handler.cpp        | 12 ++++++++++++
 util/include/teadns/builder.h |  6 ++++++
 util/src/builder.cpp          | 13 +++++++++++++
 3 files changed, 31 insertions(+)

diff --git a/server/src/handler.cpp b/server/src/handler.cpp
index 39978b3..1a5c1d1 100644
--- a/server/src/handler.cpp
+++ b/server/src/handler.cpp
@@ -69,6 +69,18 @@ void WebDNSHandler::handle_message(const std::shared_ptr<DNSServerBinding>& bind
 				a.set_type(query->qtype());
 				a.set_ttl(120);
 				a.builder<rrbuilder::A>().set_address(resp);
+			} else if(query->qclass() == rrclass::IN && query->qtype() == rrtype::TXT) {
+				auto dn = query->qname();
+				if(dn == "_acme-challenge.con-gate.work") {
+					std::cout << "  Letsencrypt request\n";
+					std::cout << "  Sending predefined key\n";
+
+					auto& a = response.push_answer(query->qname());
+					a.set_class(query->qclass());
+					a.set_type(query->qtype());
+					a.set_ttl(120);
+					a.builder<rrbuilder::TXT>().set_text("-YEqeIGJqoOz5uLbUiUfK06--n3jtVoI__6WJY-Ehgk");
+				}
 			}
 		}
 
diff --git a/util/include/teadns/builder.h b/util/include/teadns/builder.h
index f4b426b..7b2d6a1 100644
--- a/util/include/teadns/builder.h
+++ b/util/include/teadns/builder.h
@@ -143,6 +143,12 @@ namespace ts::dns {
 					uint32_t address{0};
 			);
 
+			define_builder(TXT, base,
+	               inline void set_text(const std::string& text) { this->_text = text; }
+	            private:
+	               std::string _text;
+			);
+
 			#undef define_builder
 		}
 	}
diff --git a/util/src/builder.cpp b/util/src/builder.cpp
index a197de2..b5adb98 100644
--- a/util/src/builder.cpp
+++ b/util/src/builder.cpp
@@ -119,4 +119,17 @@ bool rrbuilder::A::build(char *&buffer, size_t &max_size, std::string &error) {
 	buffer += 4;
 	max_size -= 4;
 	return true;
+}
+
+bool rrbuilder::TXT::build(char *&buffer, size_t &max_size, std::string &error) {
+	if(max_size + 1 < this->_text.size()) {
+		error = "buffer too small";
+		return false;
+	}
+
+	*buffer = this->_text.size();
+	memcpy(buffer + 1, this->_text.data(), this->_text.size());
+	buffer += this->_text.size() + 1;
+	max_size -= this->_text.size() + 1;
+	return true;
 }
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