m4: Refuse to build with OpenSSL version < 1.0.1

diff --git a/m4/ssl.m4 b/m4/ssl.m4
index 35b77ec44e50d581197d5f18f15506cc4977ae54..ef8a31132797d332f000b6fb327b0fecd886804c 100644 (file)
--- a/m4/ssl.m4
+++ b/m4/ssl.m4
@@ -28,7 +28,19 @@ AC_DEFUN([DOVECOT_SSL], [
     if test "$have_openssl" = "yes"; then
       AC_DEFINE(HAVE_OPENSSL,, [Build with OpenSSL support])
       have_ssl="yes (OpenSSL)"
-  
+
+      AC_MSG_CHECKING([if OpenSSL version is 1.0.1 or newer])
+      AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+       #include <openssl/opensslv.h>
+       #if OPENSSL_VERSION_NUMBER < 0x10001000L
+       #error "fail-compile"
+       #endif]], [[ return 0; ]])],
+       [ssl_version_ge_101=true], [ssl_version_ge_101=false])
+      AC_MSG_RESULT([$ssl_version_ge_101])
+      if test $ssl_version_ge_101 = false; then
+        AC_MSG_ERROR([Found deprecated OpenSSL version, use 1.0.1 or newer])
+      fi
+
       AC_MSG_CHECKING([if OpenSSL version is 1.0.2 or better])
 
       AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[