Update to require OpenSSL 1.0.2 or later

configure.in

@@ -1164,6 +1164,13 @@ if test $ol_with_tls = openssl || test $ol_with_tls = auto ; then
 	AC_CHECK_HEADERS(openssl/ssl.h)
 
 	if test $ac_cv_header_openssl_ssl_h = yes ; then
+		AC_PREPROC_IFELSE([AC_LANG_SOURCE(
+			[[#include <openssl/opensslv.h>]
+			[#if OPENSSL_VERSION_NUMBER < 0x1000200fL]
+			[#error "OpenSSL is too old"]
+			[#endif]])],
+			, [AC_MSG_FAILURE([OpenSSL 1.0.2a or newer required])])
+
 		AC_CHECK_LIB(ssl, SSL_CTX_set_msg_callback,
 			[have_openssl=yes
 			need_rsaref=no], [have_openssl=no],

doc/guide/admin/appendix-recommended-versions.sdf

@@ -15,7 +15,7 @@ H2: Dependency Versions
 !block table; align=Center; coltags="N,EX,EX"; title="Table 8.5: OpenLDAP Software Dependency Versions"
 Feature|Software|Version
 {{TERM[expand]TLS}}:
-|{{PRD:OpenSSL}}|0.9.7+
+|{{PRD:OpenSSL}}|1.0.2+
 |{{PRD:GnuTLS}}|2.12.0
 |{{PRD:MozNSS}}|3.12.9
 {{TERM[expand]SASL}}|{{PRD:Cyrus SASL}}|2.1.21+