Support setting client certificate and SSL options on HTTP client (#1090)

lib/inc/drogon/HttpClient.h

@@ -258,6 +258,31 @@ class DROGON_EXPORT HttpClient : public trantor::NonCopyable
         return port() == 80;
     }
 
+    /**
+     * @brief Set the client certificate used by the HTTP connection
+     *
+     * @param cert Path to the certificate
+     * @param key Path to the certificate's private key
+     * @note this method has no effect if the HTTP client is communicating via
+     * unencrypted HTTP
+     */
+    virtual void setCertPath(const std::string &cert,
+                             const std::string &key) = 0;
+
+    /**
+     * @brief Supplies command style options for `SSL_CONF_cmd`
+     *
+     * @param sslConfCmds options for SSL_CONF_cmd
+     * @note this method has no effect if the HTTP client is communicating via
+     * unencrypted HTTP
+     * @code
+     * addSSLConfigs({{"-dhparam", "/path/to/dhparam"}, {"-strict", ""}});
+     * @endcode
+     */
+    virtual void addSSLConfigs(
+        const std::vector<std::pair<std::string, std::string>>
+            &sslConfCmds) = 0;
+
     /// Create a Http client using the hostString to connect to server
     /**
      *

lib/src/HttpClientImpl.cc

@@ -39,7 +39,12 @@ void HttpClientImpl::createTcpClient()
     {
         LOG_TRACE << "useOldTLS=" << useOldTLS_;
         LOG_TRACE << "domain=" << domain_;
-        tcpClientPtr_->enableSSL(useOldTLS_, validateCert_, domain_);
+        tcpClientPtr_->enableSSL(useOldTLS_,
+                                 validateCert_,
+                                 domain_,
+                                 sslConfCmds_,
+                                 clientCertPath_,
+                                 clientKeyPath_);
     }
 #endif
     auto thisPtr = shared_from_this();
@@ -645,3 +650,19 @@ void HttpClientImpl::handleCookies(const HttpResponseImplPtr &resp)
         }
     }
 }
+
+void HttpClientImpl::setCertPath(const std::string &cert,
+                                 const std::string &key)
+{
+    clientCertPath_ = cert;
+    clientKeyPath_ = key;
+}
+
+void HttpClientImpl::addSSLConfigs(
+    const std::vector<std::pair<std::string, std::string>> &sslConfCmds)
+{
+    for (const auto &cmd : sslConfCmds)
+    {
+        sslConfCmds_.push_back(cmd);
+    }
+}

lib/src/HttpClientImpl.h

@@ -101,6 +101,10 @@ class HttpClientImpl final : public HttpClient,
         return useSSL_;
     }
 
+    void setCertPath(const std::string &cert, const std::string &key) override;
+    void addSSLConfigs(const std::vector<std::pair<std::string, std::string>>
+                           &sslConfCmds) override;
+
   private:
     std::shared_ptr<trantor::TcpClient> tcpClientPtr_;
     trantor::EventLoop *loop_;
@@ -133,6 +137,9 @@ class HttpClientImpl final : public HttpClient,
     std::shared_ptr<trantor::Resolver> resolverPtr_;
     bool useOldTLS_{false};
     std::string userAgent_{"DrogonClient"};
+    std::vector<std::pair<std::string, std::string>> sslConfCmds_;
+    std::string clientCertPath_;
+    std::string clientKeyPath_;
 };
 using HttpClientImplPtr = std::shared_ptr<HttpClientImpl>;
 }  // namespace drogon

trantor

@@ -1 +1 @@
-Subproject commit 586aacd084e088bbc041350a657b80b143820276
+Subproject commit 63ff8d9bad639c5fa3e6bd7072669813fae4c6af