Make botan’s policy configurable from a file

fix #3244

src/network/tcp_socket_handler.cpp

@@ -14,6 +14,8 @@
 #ifdef BOTAN_FOUND
 # include <botan/hex.h>
 # include <botan/tls_exceptn.h>
+# include <config/config.hpp>
+# include <utils/dirname.hpp>
 
 namespace
 {
@@ -22,11 +24,6 @@ namespace
       static Botan::AutoSeeded_RNG rng{};
       return rng;
     }
-    BiboumiTLSPolicy& get_policy()
-    {
-      static BiboumiTLSPolicy policy{};
-      return policy;
-    }
     Botan::TLS::Session_Manager_In_Memory& get_session_manager()
     {
       static Botan::TLS::Session_Manager_In_Memory session_manager{get_rng()};
@@ -233,6 +230,11 @@ void TCPSocketHandler::consume_in_buffer(const std::size_t size)
 void TCPSocketHandler::start_tls(const std::string& address, const std::string& port)
 {
   Botan::TLS::Server_Information server_info(address, "irc", std::stoul(port));
+  auto policy_directory = Config::get("policy_directory", utils::dirname(Config::get_filename()));
+  if (!policy_directory.empty() && policy_directory[policy_directory.size()-1] != '/')
+    policy_directory += '/';
+  this->policy.load(policy_directory + "policy.txt");
+  this->policy.load(policy_directory + address + ".policy.txt");
   this->tls = std::make_unique<Botan::TLS::Client>(
 # if BOTAN_VERSION_CODE >= BOTAN_VERSION_CODE_FOR(1,11,32)
       *this,
@@ -242,7 +244,7 @@ void TCPSocketHandler::start_tls(const std::string& address, const std::string&
       [this](Botan::TLS::Alert alert, const Botan::byte*, size_t) { this->tls_alert(alert); },
       [this](const Botan::TLS::Session& session) { return this->tls_session_established(session); },
 # endif
-      get_session_manager(), this->credential_manager, get_policy(),
+      get_session_manager(), this->credential_manager, this->policy,
       get_rng(), server_info, Botan::TLS::Protocol_Version::latest_tls_version());
 }
 

src/network/tcp_socket_handler.hpp

@@ -23,21 +23,7 @@
 # include <botan/types.h>
 # include <botan/botan.h>
 # include <botan/tls_session_manager.h>
-
-class BiboumiTLSPolicy: public Botan::TLS::Policy
-{
-public:
-# if BOTAN_VERSION_CODE >= BOTAN_VERSION_CODE_FOR(1,11,33)
-  bool use_ecc_point_compression() const override
-  {
-    return true;
-  }
-  bool require_cert_revocation_info() const override
-  {
-    return false;
-  }
-# endif
-};
+# include <network/tls_policy.hpp>
 
 # if BOTAN_VERSION_CODE >= BOTAN_VERSION_CODE_FOR(1,11,32)
 #  define BOTAN_TLS_CALLBACKS_OVERRIDE override final
@@ -230,6 +216,7 @@ protected:
 protected:
   BasicCredentialsManager credential_manager;
 private:
+  BiboumiTLSPolicy policy;
   /**
    * We use a unique_ptr because we may not want to create the object at
    * all. The Botan::TLS::Client object generates a handshake message and

src/network/tls_policy.cpp

@@ -0,0 +1,48 @@
+#include "biboumi.h"
+
+#ifdef BOTAN_FOUND
+
+#include <fstream>
+
+#include <utils/tolower.hpp>
+
+#include <network/tls_policy.hpp>
+#include <logger/logger.hpp>
+
+bool BiboumiTLSPolicy::load(const std::string& filename)
+{
+  std::ifstream is(filename.data());
+  if (is)
+    {
+      try {
+          this->load(is);
+          log_info("Successfully loaded policy file: ", filename);
+          return true;
+        } catch (const Botan::Exception& e) {
+          log_error("Failed to parse policy_file ", filename, ": ", e.what());
+          return false;
+        }
+    }
+  log_info("Could not open policy file: ", filename);
+  return false;
+}
+
+void BiboumiTLSPolicy::load(std::istream& is)
+{
+  const auto dict = Botan::read_cfg(is);
+  for (const auto& pair: dict)
+    {
+      // Workaround for options that are not overridden in Botan::TLS::Text_Policy
+      if (pair.first == "require_cert_revocation_info")
+        this->req_cert_revocation_info = !(pair.second == "0" || utils::tolower(pair.second) == "false");
+      else
+        this->set(pair.first, pair.second);
+    }
+}
+
+bool BiboumiTLSPolicy::require_cert_revocation_info() const
+{
+  return this->req_cert_revocation_info;
+}
+
+#endif

src/network/tls_policy.hpp

@@ -0,0 +1,28 @@
+#pragma once
+
+#include "biboumi.h"
+
+#ifdef BOTAN_FOUND
+
+#include <botan/tls_policy.h>
+
+class BiboumiTLSPolicy: public Botan::TLS::Text_Policy
+{
+public:
+  BiboumiTLSPolicy():
+      Botan::TLS::Text_Policy({})
+  {}
+  bool load(const std::string& filename);
+  void load(std::istream& iss);
+
+  BiboumiTLSPolicy(const BiboumiTLSPolicy &) = delete;
+  BiboumiTLSPolicy(BiboumiTLSPolicy &&) = delete;
+  BiboumiTLSPolicy &operator=(const BiboumiTLSPolicy &) = delete;
+  BiboumiTLSPolicy &operator=(BiboumiTLSPolicy &&) = delete;
+
+  bool require_cert_revocation_info() const override;
+protected:
+  bool req_cert_revocation_info{true};
+};
+
+#endif