cmake: add rustls

CMake/Findrustls.cmake

@@ -0,0 +1,32 @@
+#***************************************************************************
+#                                  _   _ ____  _
+#  Project                     ___| | | |  _ \| |
+#                             / __| | | | |_) | |
+#                            | (__| |_| |  _ <| |___
+#                             \___|\___/|_| \_\_____|
+#
+# Copyright (C) Daniel Stenberg, <[email protected]>, et al.
+#
+# This software is licensed as described in the file COPYING, which
+# you should have received as part of this distribution. The terms
+# are also available at https://curl.se/docs/copyright.html.
+#
+# You may opt to use, copy, modify, merge, publish, distribute and/or sell
+# copies of the Software, and permit persons to whom the Software is
+# furnished to do so, under the terms of the COPYING file.
+#
+# This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+# KIND, either express or implied.
+#
+# SPDX-License-Identifier: curl
+#
+###########################################################################
+find_path(RUSTLS_INCLUDE_DIRS rustls.h)
+
+find_library(RUSTLS_LIBRARY rustls)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(rustls DEFAULT_MSG
+  RUSTLS_INCLUDE_DIRS RUSTLS_LIBRARY)
+
+mark_as_advanced(RUSTLS_INCLUDE_DIRS RUSTLS_LIBRARY)

CMakeLists.txt

@@ -457,6 +457,7 @@ cmake_dependent_option(CURL_USE_MBEDTLS "Enable mbedTLS for SSL/TLS" OFF CURL_EN
 cmake_dependent_option(CURL_USE_BEARSSL "Enable BearSSL for SSL/TLS" OFF CURL_ENABLE_SSL OFF)
 cmake_dependent_option(CURL_USE_WOLFSSL "Enable wolfSSL for SSL/TLS" OFF CURL_ENABLE_SSL OFF)
 cmake_dependent_option(CURL_USE_GNUTLS "Enable GnuTLS for SSL/TLS" OFF CURL_ENABLE_SSL OFF)
+cmake_dependent_option(CURL_USE_RUSTLS "Enable rustls for SSL/TLS" OFF CURL_ENABLE_SSL OFF)
 
 set(_openssl_default ON)
 if(WIN32 OR CURL_USE_SECTRANSP OR CURL_USE_SCHANNEL OR CURL_USE_MBEDTLS OR CURL_USE_WOLFSSL)
@@ -473,6 +474,7 @@ count_true(_enabled_ssl_options_count
   CURL_USE_BEARSSL
   CURL_USE_WOLFSSL
   CURL_USE_GNUTLS
+  CURL_USE_RUSTLS
 )
 if(_enabled_ssl_options_count GREATER 1)
   set(CURL_WITH_MULTI_SSL ON)
@@ -610,6 +612,19 @@ if(CURL_USE_GNUTLS)
   endif()
 endif()
 
+if(CURL_USE_RUSTLS)
+  find_package(rustls REQUIRED)
+  set(_ssl_enabled ON)
+  set(USE_RUSTLS ON)
+  list(APPEND CURL_LIBS ${RUSTLS_LIBRARY})
+  include_directories(${RUSTLS_INCLUDE_DIRS})
+
+  if(CURL_DEFAULT_SSL_BACKEND AND CURL_DEFAULT_SSL_BACKEND STREQUAL "rustls")
+    set(valid_default_ssl_backend TRUE)
+  endif()
+  set(curl_ca_bundle_supported TRUE) # TODO ?
+endif()
+
 if(CURL_DEFAULT_SSL_BACKEND AND NOT _valid_default_ssl_backend)
   message(FATAL_ERROR "CURL_DEFAULT_SSL_BACKEND '${CURL_DEFAULT_SSL_BACKEND}' not enabled.")
 endif()
@@ -1860,6 +1875,7 @@ if(NOT CURL_DISABLE_INSTALL)
   _add_if("BearSSL"          _ssl_enabled AND USE_BEARSSL)
   _add_if("wolfSSL"          _ssl_enabled AND USE_WOLFSSL)
   _add_if("GnuTLS"           _ssl_enabled AND USE_GNUTLS)
+  _add_if("rustls"           _ssl_enabled AND USE_RUSTLS)
 
   if(_items)
     if(NOT CMAKE_VERSION VERSION_LESS 3.13)

lib/curl_config.h.cmake

@@ -689,6 +689,9 @@ ${SIZEOF_TIME_T_CODE}
 /* if BearSSL is enabled */
 #cmakedefine USE_BEARSSL 1
 
+/* if rustls is enabled */
+#cmakedefine USE_RUSTLS 1
+
 /* if wolfSSL is enabled */
 #cmakedefine USE_WOLFSSL 1