From c0cf030528e5ecbb74750eb76bb7a360da62f209 Mon Sep 17 00:00:00 2001
From: Vinnie Falco <vinnie.falco@gmail.com>
Date: Sun, 1 Oct 2017 10:33:49 -0700
Subject: [PATCH] OpenSSL targets are optional (CMake)

---
 CHANGELOG.md                                  |  1 +
 example/advanced/server-flex/CMakeLists.txt   | 31 ++++++++++---------
 example/http/client/async-ssl/CMakeLists.txt  | 27 +++++++++-------
 example/http/client/coro-ssl/CMakeLists.txt   | 27 +++++++++-------
 example/http/client/sync-ssl/CMakeLists.txt   | 27 +++++++++-------
 example/http/server/async-ssl/CMakeLists.txt  | 27 +++++++++-------
 example/http/server/coro-ssl/CMakeLists.txt   | 27 +++++++++-------
 example/http/server/flex/CMakeLists.txt       | 29 +++++++++--------
 .../http/server/stackless-ssl/CMakeLists.txt  | 27 +++++++++-------
 example/http/server/sync-ssl/CMakeLists.txt   | 25 ++++++++-------
 .../websocket/client/async-ssl/CMakeLists.txt | 27 +++++++++-------
 .../websocket/client/coro-ssl/CMakeLists.txt  | 27 +++++++++-------
 .../websocket/client/sync-ssl/CMakeLists.txt  | 27 +++++++++-------
 .../websocket/server/async-ssl/CMakeLists.txt | 27 +++++++++-------
 .../websocket/server/coro-ssl/CMakeLists.txt  | 27 +++++++++-------
 .../server/stackless-ssl/CMakeLists.txt       | 27 +++++++++-------
 .../websocket/server/sync-ssl/CMakeLists.txt  | 27 +++++++++-------
 17 files changed, 243 insertions(+), 194 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5df70e23..8798fcfc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 Version 120:
 
 * Fix spurious strand_ in advanced_server_flex
+* OpenSSL targets are optional (CMake)
 
 --------------------------------------------------------------------------------
 
diff --git a/example/advanced/server-flex/CMakeLists.txt b/example/advanced/server-flex/CMakeLists.txt
index 3129be74..00697288 100644
--- a/example/advanced/server-flex/CMakeLists.txt
+++ b/example/advanced/server-flex/CMakeLists.txt
@@ -7,19 +7,22 @@
 # Official repository: https://github.com/boostorg/beast
 #
 
-GroupSources(include/boost/beast beast)
-GroupSources(example/common common)
-GroupSources(example/advanced/server-flex "/")
+if (OPENSSL_FOUND)
+    GroupSources(include/boost/beast beast)
+    GroupSources(example/common common)
+    GroupSources(example/advanced/server-flex "/")
 
-add_executable (advanced-server-flex
-    ${BOOST_BEAST_INCLUDES}
-    ${PROJECT_SOURCE_DIR}/example/common/detect_ssl.hpp
-    ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
-    ${PROJECT_SOURCE_DIR}/example/common/ssl_stream.hpp
-    Jamfile
-    advanced_server_flex.cpp
-)
-
-target_link_libraries (advanced-server-flex
-    ${OPENSSL_LIBRARIES}
+    add_executable (advanced-server-flex
+        ${BOOST_BEAST_INCLUDES}
+        ${PROJECT_SOURCE_DIR}/example/common/detect_ssl.hpp
+        ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
+        ${PROJECT_SOURCE_DIR}/example/common/ssl_stream.hpp
+        Jamfile
+        advanced_server_flex.cpp
     )
+
+    target_link_libraries (advanced-server-flex
+        ${OPENSSL_LIBRARIES}
+        )
+
+endif()
diff --git a/example/http/client/async-ssl/CMakeLists.txt b/example/http/client/async-ssl/CMakeLists.txt
index c4bfec12..92675aed 100644
--- a/example/http/client/async-ssl/CMakeLists.txt
+++ b/example/http/client/async-ssl/CMakeLists.txt
@@ -7,17 +7,20 @@
 # Official repository: https://github.com/boostorg/beast
 #
 
-GroupSources(include/boost/beast beast)
-GroupSources(example/common common)
-GroupSources(example/http/client/async-ssl "/")
+if (OPENSSL_FOUND)
+    GroupSources(include/boost/beast beast)
+    GroupSources(example/common common)
+    GroupSources(example/http/client/async-ssl "/")
 
-add_executable (http-client-async-ssl
-    ${BOOST_BEAST_INCLUDES}
-    ${PROJECT_SOURCE_DIR}/example/common/root_certificates.hpp
-    Jamfile
-    http_client_async_ssl.cpp
-)
-
-target_link_libraries (http-client-async-ssl
-    ${OPENSSL_LIBRARIES}
+    add_executable (http-client-async-ssl
+        ${BOOST_BEAST_INCLUDES}
+        ${PROJECT_SOURCE_DIR}/example/common/root_certificates.hpp
+        Jamfile
+        http_client_async_ssl.cpp
     )
+
+    target_link_libraries (http-client-async-ssl
+        ${OPENSSL_LIBRARIES}
+        )
+
+endif()
diff --git a/example/http/client/coro-ssl/CMakeLists.txt b/example/http/client/coro-ssl/CMakeLists.txt
index 2a6b5564..a8ac90af 100644
--- a/example/http/client/coro-ssl/CMakeLists.txt
+++ b/example/http/client/coro-ssl/CMakeLists.txt
@@ -7,17 +7,20 @@
 # Official repository: https://github.com/boostorg/beast
 #
 
-GroupSources(include/boost/beast beast)
-GroupSources(example/common common)
-GroupSources(example/http/client/coro-ssl "/")
+if (OPENSSL_FOUND)
+    GroupSources(include/boost/beast beast)
+    GroupSources(example/common common)
+    GroupSources(example/http/client/coro-ssl "/")
 
-add_executable (http-client-coro-ssl
-    ${BOOST_BEAST_INCLUDES}
-    ${PROJECT_SOURCE_DIR}/example/common/root_certificates.hpp
-    Jamfile
-    http_client_coro_ssl.cpp
-)
-
-target_link_libraries (http-client-coro-ssl
-    ${OPENSSL_LIBRARIES}
+    add_executable (http-client-coro-ssl
+        ${BOOST_BEAST_INCLUDES}
+        ${PROJECT_SOURCE_DIR}/example/common/root_certificates.hpp
+        Jamfile
+        http_client_coro_ssl.cpp
     )
+
+    target_link_libraries (http-client-coro-ssl
+        ${OPENSSL_LIBRARIES}
+        )
+
+endif()
diff --git a/example/http/client/sync-ssl/CMakeLists.txt b/example/http/client/sync-ssl/CMakeLists.txt
index 7c229366..df1d9827 100644
--- a/example/http/client/sync-ssl/CMakeLists.txt
+++ b/example/http/client/sync-ssl/CMakeLists.txt
@@ -7,17 +7,20 @@
 # Official repository: https://github.com/boostorg/beast
 #
 
-GroupSources(include/boost/beast beast)
-GroupSources(example/common common)
-GroupSources(example/http/client/sync-ssl "/")
+if (OPENSSL_FOUND)
+    GroupSources(include/boost/beast beast)
+    GroupSources(example/common common)
+    GroupSources(example/http/client/sync-ssl "/")
 
-add_executable (http-client-sync-ssl
-    ${BOOST_BEAST_INCLUDES}
-    ${PROJECT_SOURCE_DIR}/example/common/root_certificates.hpp
-    Jamfile
-    http_client_sync_ssl.cpp
-)
-
-target_link_libraries (http-client-sync-ssl
-    ${OPENSSL_LIBRARIES}
+    add_executable (http-client-sync-ssl
+        ${BOOST_BEAST_INCLUDES}
+        ${PROJECT_SOURCE_DIR}/example/common/root_certificates.hpp
+        Jamfile
+        http_client_sync_ssl.cpp
     )
+
+    target_link_libraries (http-client-sync-ssl
+        ${OPENSSL_LIBRARIES}
+        )
+
+endif()
diff --git a/example/http/server/async-ssl/CMakeLists.txt b/example/http/server/async-ssl/CMakeLists.txt
index b5c740cf..bc6f9c0b 100644
--- a/example/http/server/async-ssl/CMakeLists.txt
+++ b/example/http/server/async-ssl/CMakeLists.txt
@@ -7,17 +7,20 @@
 # Official repository: https://github.com/boostorg/beast
 #
 
-GroupSources(include/boost/beast beast)
-GroupSources(example/common common)
-GroupSources(example/http/server/async-ssl "/")
+if (OPENSSL_FOUND)
+    GroupSources(include/boost/beast beast)
+    GroupSources(example/common common)
+    GroupSources(example/http/server/async-ssl "/")
 
-add_executable (http-server-async-ssl
-    ${BOOST_BEAST_INCLUDES}
-    ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
-    Jamfile
-    http_server_async_ssl.cpp
-)
-
-target_link_libraries (http-server-async-ssl
-    ${OPENSSL_LIBRARIES}
+    add_executable (http-server-async-ssl
+        ${BOOST_BEAST_INCLUDES}
+        ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
+        Jamfile
+        http_server_async_ssl.cpp
     )
+
+    target_link_libraries (http-server-async-ssl
+        ${OPENSSL_LIBRARIES}
+        )
+
+endif()
diff --git a/example/http/server/coro-ssl/CMakeLists.txt b/example/http/server/coro-ssl/CMakeLists.txt
index 5a37eeed..dc80a112 100644
--- a/example/http/server/coro-ssl/CMakeLists.txt
+++ b/example/http/server/coro-ssl/CMakeLists.txt
@@ -7,17 +7,20 @@
 # Official repository: https://github.com/boostorg/beast
 #
 
-GroupSources(include/boost/beast beast)
-GroupSources(example/common common)
-GroupSources(example/http/server/coro-ssl "/")
+if (OPENSSL_FOUND)
+    GroupSources(include/boost/beast beast)
+    GroupSources(example/common common)
+    GroupSources(example/http/server/coro-ssl "/")
 
-add_executable (http-server-coro-ssl
-    ${BOOST_BEAST_INCLUDES}
-    ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
-    Jamfile
-    http_server_coro_ssl.cpp
-)
-
-target_link_libraries (http-server-coro-ssl
-    ${OPENSSL_LIBRARIES}
+    add_executable (http-server-coro-ssl
+        ${BOOST_BEAST_INCLUDES}
+        ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
+        Jamfile
+        http_server_coro_ssl.cpp
     )
+
+    target_link_libraries (http-server-coro-ssl
+        ${OPENSSL_LIBRARIES}
+        )
+
+endif()
diff --git a/example/http/server/flex/CMakeLists.txt b/example/http/server/flex/CMakeLists.txt
index a02726d8..cc6e0cb6 100644
--- a/example/http/server/flex/CMakeLists.txt
+++ b/example/http/server/flex/CMakeLists.txt
@@ -7,18 +7,21 @@
 # Official repository: https://github.com/boostorg/beast
 #
 
-GroupSources(include/boost/beast beast)
-GroupSources(example/common common)
-GroupSources(example/http/server/flex "/")
+if (OPENSSL_FOUND)
+    GroupSources(include/boost/beast beast)
+    GroupSources(example/common common)
+    GroupSources(example/http/server/flex "/")
 
-add_executable (http-server-flex
-    ${BOOST_BEAST_INCLUDES}
-    ${PROJECT_SOURCE_DIR}/example/common/detect_ssl.hpp
-    ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
-    Jamfile
-    http_server_flex.cpp
-)
-
-target_link_libraries (http-server-flex
-    ${OPENSSL_LIBRARIES}
+    add_executable (http-server-flex
+        ${BOOST_BEAST_INCLUDES}
+        ${PROJECT_SOURCE_DIR}/example/common/detect_ssl.hpp
+        ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
+        Jamfile
+        http_server_flex.cpp
     )
+
+    target_link_libraries (http-server-flex
+        ${OPENSSL_LIBRARIES}
+        )
+
+endif()
diff --git a/example/http/server/stackless-ssl/CMakeLists.txt b/example/http/server/stackless-ssl/CMakeLists.txt
index ae9f69b2..e374e85e 100644
--- a/example/http/server/stackless-ssl/CMakeLists.txt
+++ b/example/http/server/stackless-ssl/CMakeLists.txt
@@ -7,17 +7,20 @@
 # Official repository: https://github.com/boostorg/beast
 #
 
-GroupSources(include/boost/beast beast)
-GroupSources(example/common common)
-GroupSources(example/http/server/stackless-ssl "/")
+if (OPENSSL_FOUND)
+    GroupSources(include/boost/beast beast)
+    GroupSources(example/common common)
+    GroupSources(example/http/server/stackless-ssl "/")
 
-add_executable (http-server-stackless-ssl
-    ${BOOST_BEAST_INCLUDES}
-    ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
-    Jamfile
-    http_server_stackless_ssl.cpp
-)
-
-target_link_libraries (http-server-stackless-ssl
-    ${OPENSSL_LIBRARIES}
+    add_executable (http-server-stackless-ssl
+        ${BOOST_BEAST_INCLUDES}
+        ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
+        Jamfile
+        http_server_stackless_ssl.cpp
     )
+
+    target_link_libraries (http-server-stackless-ssl
+        ${OPENSSL_LIBRARIES}
+        )
+
+endif()
diff --git a/example/http/server/sync-ssl/CMakeLists.txt b/example/http/server/sync-ssl/CMakeLists.txt
index 03824e51..5747923e 100644
--- a/example/http/server/sync-ssl/CMakeLists.txt
+++ b/example/http/server/sync-ssl/CMakeLists.txt
@@ -7,16 +7,19 @@
 # Official repository: https://github.com/boostorg/beast
 #
 
-GroupSources(include/boost/beast beast)
-GroupSources(example/common common)
-GroupSources(example/http/server/sync-ssl "/")
+if (OPENSSL_FOUND)
+    GroupSources(include/boost/beast beast)
+    GroupSources(example/common common)
+    GroupSources(example/http/server/sync-ssl "/")
 
-add_executable (http-server-sync-ssl
-    ${BOOST_BEAST_INCLUDES}
-    ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
-    Jamfile
-    http_server_sync_ssl.cpp
-)
-target_link_libraries (http-server-sync-ssl
-    ${OPENSSL_LIBRARIES}
+    add_executable (http-server-sync-ssl
+        ${BOOST_BEAST_INCLUDES}
+        ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
+        Jamfile
+        http_server_sync_ssl.cpp
     )
+    target_link_libraries (http-server-sync-ssl
+        ${OPENSSL_LIBRARIES}
+        )
+
+endif()
diff --git a/example/websocket/client/async-ssl/CMakeLists.txt b/example/websocket/client/async-ssl/CMakeLists.txt
index e7ceb413..4b522855 100644
--- a/example/websocket/client/async-ssl/CMakeLists.txt
+++ b/example/websocket/client/async-ssl/CMakeLists.txt
@@ -7,17 +7,20 @@
 # Official repository: https://github.com/boostorg/beast
 #
 
-GroupSources(include/boost/beast beast)
-GroupSources(example/common common)
-GroupSources(example/websocket/client/async-ssl "/")
+if (OPENSSL_FOUND)
+    GroupSources(include/boost/beast beast)
+    GroupSources(example/common common)
+    GroupSources(example/websocket/client/async-ssl "/")
 
-add_executable (websocket-client-async-ssl
-    ${BOOST_BEAST_INCLUDES}
-    ${PROJECT_SOURCE_DIR}/example/common/root_certificates.hpp
-    Jamfile
-    websocket_client_async_ssl.cpp
-)
-
-target_link_libraries (websocket-client-async-ssl
-    ${OPENSSL_LIBRARIES}
+    add_executable (websocket-client-async-ssl
+        ${BOOST_BEAST_INCLUDES}
+        ${PROJECT_SOURCE_DIR}/example/common/root_certificates.hpp
+        Jamfile
+        websocket_client_async_ssl.cpp
     )
+
+    target_link_libraries (websocket-client-async-ssl
+        ${OPENSSL_LIBRARIES}
+        )
+
+endif()
diff --git a/example/websocket/client/coro-ssl/CMakeLists.txt b/example/websocket/client/coro-ssl/CMakeLists.txt
index c9f9bbcf..13b093cb 100644
--- a/example/websocket/client/coro-ssl/CMakeLists.txt
+++ b/example/websocket/client/coro-ssl/CMakeLists.txt
@@ -7,17 +7,20 @@
 # Official repository: https://github.com/boostorg/beast
 #
 
-GroupSources(include/boost/beast beast)
-GroupSources(example/common common)
-GroupSources(example/websocket/client/coro-ssl "/")
+if (OPENSSL_FOUND)
+    GroupSources(include/boost/beast beast)
+    GroupSources(example/common common)
+    GroupSources(example/websocket/client/coro-ssl "/")
 
-add_executable (websocket-client-coro-ssl
-    ${BOOST_BEAST_INCLUDES}
-    ${PROJECT_SOURCE_DIR}/example/common/root_certificates.hpp
-    Jamfile
-    websocket_client_coro_ssl.cpp
-)
-
-target_link_libraries (websocket-client-coro-ssl
-    ${OPENSSL_LIBRARIES}
+    add_executable (websocket-client-coro-ssl
+        ${BOOST_BEAST_INCLUDES}
+        ${PROJECT_SOURCE_DIR}/example/common/root_certificates.hpp
+        Jamfile
+        websocket_client_coro_ssl.cpp
     )
+
+    target_link_libraries (websocket-client-coro-ssl
+        ${OPENSSL_LIBRARIES}
+        )
+
+endif()
diff --git a/example/websocket/client/sync-ssl/CMakeLists.txt b/example/websocket/client/sync-ssl/CMakeLists.txt
index a7658b7e..5a5f368e 100644
--- a/example/websocket/client/sync-ssl/CMakeLists.txt
+++ b/example/websocket/client/sync-ssl/CMakeLists.txt
@@ -7,17 +7,20 @@
 # Official repository: https://github.com/boostorg/beast
 #
 
-GroupSources(include/boost/beast beast)
-GroupSources(example/common common)
-GroupSources(example/websocket/client/sync-ssl "/")
+if (OPENSSL_FOUND)
+    GroupSources(include/boost/beast beast)
+    GroupSources(example/common common)
+    GroupSources(example/websocket/client/sync-ssl "/")
 
-add_executable (websocket-client-sync-ssl
-    ${BOOST_BEAST_INCLUDES}
-    ${PROJECT_SOURCE_DIR}/example/common/root_certificates.hpp
-    Jamfile
-    websocket_client_sync_ssl.cpp
-)
-
-target_link_libraries (websocket-client-sync-ssl
-    ${OPENSSL_LIBRARIES}
+    add_executable (websocket-client-sync-ssl
+        ${BOOST_BEAST_INCLUDES}
+        ${PROJECT_SOURCE_DIR}/example/common/root_certificates.hpp
+        Jamfile
+        websocket_client_sync_ssl.cpp
     )
+
+    target_link_libraries (websocket-client-sync-ssl
+        ${OPENSSL_LIBRARIES}
+        )
+
+endif()
diff --git a/example/websocket/server/async-ssl/CMakeLists.txt b/example/websocket/server/async-ssl/CMakeLists.txt
index 408f39bf..f8fed86e 100644
--- a/example/websocket/server/async-ssl/CMakeLists.txt
+++ b/example/websocket/server/async-ssl/CMakeLists.txt
@@ -7,17 +7,20 @@
 # Official repository: https://github.com/boostorg/beast
 #
 
-GroupSources(include/boost/beast beast)
-GroupSources(example/common common)
-GroupSources(example/websocket/server/async-ssl "/")
+if (OPENSSL_FOUND)
+    GroupSources(include/boost/beast beast)
+    GroupSources(example/common common)
+    GroupSources(example/websocket/server/async-ssl "/")
 
-add_executable (websocket-server-async-ssl
-    ${BOOST_BEAST_INCLUDES}
-    ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
-    Jamfile
-    websocket_server_async_ssl.cpp
-)
-
-target_link_libraries (websocket-server-async-ssl
-    ${OPENSSL_LIBRARIES}
+    add_executable (websocket-server-async-ssl
+        ${BOOST_BEAST_INCLUDES}
+        ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
+        Jamfile
+        websocket_server_async_ssl.cpp
     )
+
+    target_link_libraries (websocket-server-async-ssl
+        ${OPENSSL_LIBRARIES}
+        )
+
+endif()
diff --git a/example/websocket/server/coro-ssl/CMakeLists.txt b/example/websocket/server/coro-ssl/CMakeLists.txt
index 9a5e6a53..b6eb14b9 100644
--- a/example/websocket/server/coro-ssl/CMakeLists.txt
+++ b/example/websocket/server/coro-ssl/CMakeLists.txt
@@ -7,17 +7,20 @@
 # Official repository: https://github.com/boostorg/beast
 #
 
-GroupSources(include/boost/beast beast)
-GroupSources(example/common common)
-GroupSources(example/websocket/server/coro-ssl "/")
+if (OPENSSL_FOUND)
+    GroupSources(include/boost/beast beast)
+    GroupSources(example/common common)
+    GroupSources(example/websocket/server/coro-ssl "/")
 
-add_executable (websocket-server-coro-ssl
-    ${BOOST_BEAST_INCLUDES}
-    ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
-    Jamfile
-    websocket_server_coro_ssl.cpp
-)
-
-target_link_libraries (websocket-server-coro-ssl
-    ${OPENSSL_LIBRARIES}
+    add_executable (websocket-server-coro-ssl
+        ${BOOST_BEAST_INCLUDES}
+        ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
+        Jamfile
+        websocket_server_coro_ssl.cpp
     )
+
+    target_link_libraries (websocket-server-coro-ssl
+        ${OPENSSL_LIBRARIES}
+        )
+
+endif()
diff --git a/example/websocket/server/stackless-ssl/CMakeLists.txt b/example/websocket/server/stackless-ssl/CMakeLists.txt
index 6dfedbd9..9c717d62 100644
--- a/example/websocket/server/stackless-ssl/CMakeLists.txt
+++ b/example/websocket/server/stackless-ssl/CMakeLists.txt
@@ -7,17 +7,20 @@
 # Official repository: https://github.com/boostorg/beast
 #
 
-GroupSources(include/boost/beast beast)
-GroupSources(example/common common)
-GroupSources(example/websocket/server/stackless-ssl "/")
+if (OPENSSL_FOUND)
+    GroupSources(include/boost/beast beast)
+    GroupSources(example/common common)
+    GroupSources(example/websocket/server/stackless-ssl "/")
 
-add_executable (websocket-server-stackless-ssl
-    ${BOOST_BEAST_INCLUDES}
-    ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
-    Jamfile
-    websocket_server_stackless_ssl.cpp
-)
-
-target_link_libraries (websocket-server-stackless-ssl
-    ${OPENSSL_LIBRARIES}
+    add_executable (websocket-server-stackless-ssl
+        ${BOOST_BEAST_INCLUDES}
+        ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
+        Jamfile
+        websocket_server_stackless_ssl.cpp
     )
+
+    target_link_libraries (websocket-server-stackless-ssl
+        ${OPENSSL_LIBRARIES}
+        )
+
+endif()
diff --git a/example/websocket/server/sync-ssl/CMakeLists.txt b/example/websocket/server/sync-ssl/CMakeLists.txt
index 3ee83df2..35157acb 100644
--- a/example/websocket/server/sync-ssl/CMakeLists.txt
+++ b/example/websocket/server/sync-ssl/CMakeLists.txt
@@ -7,17 +7,20 @@
 # Official repository: https://github.com/boostorg/beast
 #
 
-GroupSources(include/boost/beast beast)
-GroupSources(example/common common)
-GroupSources(example/websocket/server/sync-ssl "/")
+if (OPENSSL_FOUND)
+    GroupSources(include/boost/beast beast)
+    GroupSources(example/common common)
+    GroupSources(example/websocket/server/sync-ssl "/")
 
-add_executable (websocket-server-sync-ssl
-    ${BOOST_BEAST_INCLUDES}
-    ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
-    Jamfile
-    websocket_server_sync_ssl.cpp
-)
-
-target_link_libraries (websocket-server-sync-ssl
-    ${OPENSSL_LIBRARIES}
+    add_executable (websocket-server-sync-ssl
+        ${BOOST_BEAST_INCLUDES}
+        ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
+        Jamfile
+        websocket_server_sync_ssl.cpp
     )
+
+    target_link_libraries (websocket-server-sync-ssl
+        ${OPENSSL_LIBRARIES}
+        )
+
+endif()