Update SSL related code

Author: yhirose

httplib.h

@@ -7127,64 +7127,50 @@ static SSLInit sslinit_;
 inline SSLServer::SSLServer(const char *cert_path, const char *private_key_path,
                             const char *client_ca_cert_file_path,
                             const char *client_ca_cert_dir_path) {
-  ctx_ = SSL_CTX_new(TLS_method());
+  ctx_ = SSL_CTX_new(TLS_server_method());
 
   if (ctx_) {
     SSL_CTX_set_options(ctx_,
-                        SSL_OP_ALL | SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3 |
-                            SSL_OP_NO_COMPRESSION |
+                        SSL_OP_NO_COMPRESSION |
                             SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION);
 
-    // auto ecdh = EC_KEY_new_by_curve_name(NID_X9_62_prime256v1);
-    // SSL_CTX_set_tmp_ecdh(ctx_, ecdh);
-    // EC_KEY_free(ecdh);
+    SSL_CTX_set_min_proto_version(ctx_, TLS1_1_VERSION);
 
     if (SSL_CTX_use_certificate_chain_file(ctx_, cert_path) != 1 ||
         SSL_CTX_use_PrivateKey_file(ctx_, private_key_path, SSL_FILETYPE_PEM) !=
             1) {
       SSL_CTX_free(ctx_);
       ctx_ = nullptr;
     } else if (client_ca_cert_file_path || client_ca_cert_dir_path) {
-      // if (client_ca_cert_file_path) {
-      //   auto list = SSL_load_client_CA_file(client_ca_cert_file_path);
-      //   SSL_CTX_set_client_CA_list(ctx_, list);
-      // }
-
       SSL_CTX_load_verify_locations(ctx_, client_ca_cert_file_path,
                                     client_ca_cert_dir_path);
 
       SSL_CTX_set_verify(
-          ctx_,
-          SSL_VERIFY_PEER |
-              SSL_VERIFY_FAIL_IF_NO_PEER_CERT, // SSL_VERIFY_CLIENT_ONCE,
-          nullptr);
+          ctx_, SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT, nullptr);
     }
   }
 }
 
 inline SSLServer::SSLServer(X509 *cert, EVP_PKEY *private_key,
                             X509_STORE *client_ca_cert_store) {
-  ctx_ = SSL_CTX_new(SSLv23_server_method());
+  ctx_ = SSL_CTX_new(TLS_server_method());
 
   if (ctx_) {
     SSL_CTX_set_options(ctx_,
-                        SSL_OP_ALL | SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3 |
-                            SSL_OP_NO_COMPRESSION |
+                        SSL_OP_NO_COMPRESSION |
                             SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION);
 
+    SSL_CTX_set_min_proto_version(ctx_, TLS1_1_VERSION);
+
     if (SSL_CTX_use_certificate(ctx_, cert) != 1 ||
         SSL_CTX_use_PrivateKey(ctx_, private_key) != 1) {
       SSL_CTX_free(ctx_);
       ctx_ = nullptr;
     } else if (client_ca_cert_store) {
-
       SSL_CTX_set_cert_store(ctx_, client_ca_cert_store);
 
       SSL_CTX_set_verify(
-          ctx_,
-          SSL_VERIFY_PEER |
-              SSL_VERIFY_FAIL_IF_NO_PEER_CERT, // SSL_VERIFY_CLIENT_ONCE,
-          nullptr);
+          ctx_, SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT, nullptr);
     }
   }
 }
@@ -7249,12 +7235,13 @@ inline SSLClient::SSLClient(const std::string &host, int port,
                             const std::string &client_cert_path,
                             const std::string &client_key_path)
     : ClientImpl(host, port, client_cert_path, client_key_path) {
-  ctx_ = SSL_CTX_new(SSLv23_client_method());
+  ctx_ = SSL_CTX_new(TLS_client_method());
 
   detail::split(&host_[0], &host_[host_.size()], '.',
                 [&](const char *b, const char *e) {
                   host_components_.emplace_back(std::string(b, e));
                 });
+
   if (!client_cert_path.empty() && !client_key_path.empty()) {
     if (SSL_CTX_use_certificate_file(ctx_, client_cert_path.c_str(),
                                      SSL_FILETYPE_PEM) != 1 ||
@@ -7269,12 +7256,13 @@ inline SSLClient::SSLClient(const std::string &host, int port,
 inline SSLClient::SSLClient(const std::string &host, int port,
                             X509 *client_cert, EVP_PKEY *client_key)
     : ClientImpl(host, port) {
-  ctx_ = SSL_CTX_new(SSLv23_client_method());
+  ctx_ = SSL_CTX_new(TLS_client_method());
 
   detail::split(&host_[0], &host_[host_.size()], '.',
                 [&](const char *b, const char *e) {
                   host_components_.emplace_back(std::string(b, e));
                 });
+
   if (client_cert != nullptr && client_key != nullptr) {
     if (SSL_CTX_use_certificate(ctx_, client_cert) != 1 ||
         SSL_CTX_use_PrivateKey(ctx_, client_key) != 1) {