[ntpsec commit] Add the minimum-OpenSSL-version check from the old autoconf build.

[Eric S. Raymond]

Module:    ntpsec
Branch:    master
Commit:    6526c56994fbac845b7b9da7561e530b093f1d4b
Changeset: http://git.ntpsec.org/ntpsec/commit/?id=6526c56994fbac845b7b9da7561e530b093f1d4b

Author:    Eric S. Raymond <esr at thyrsus.com>
Date:      Thu Oct  1 07:13:00 2015 -0400

Add the minimum-OpenSSL-version check from the old autoconf build.

---

 pylib/check_openssl.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/pylib/check_openssl.py b/pylib/check_openssl.py
index 8e6cffd..9e6f691 100644
--- a/pylib/check_openssl.py
+++ b/pylib/check_openssl.py
@@ -5,9 +5,13 @@ from check_posix_thread_version import check_posix_thread_version
 
 import os
 
+# Versions older than 0.9.7d were deemed incompatible in NTP Classic.
 OPENSSL_FRAG = """
 %s
 int main () {
+#if OPENSSL_VERSION_NUMBER < 0x0090704fL
+#error OpenSSL is too old.
+#endif
 	ERR_load_BIO_strings();
 	OpenSSL_add_all_algorithms();
 	return 0;
@@ -28,6 +32,7 @@ def configure_ssl(ctx):
 		"openssl/rand.h",
 		"openssl/objects.h",
 		"openssl/x509v3.h",
+		"openssl/ssl.h",
 	)
 
 	for hdr in headers: