A autoconf checks for libz and libdl when OpenSSL is enabled to allow for static linking of OpenSSL (via CFLAGS=-static).
diff --git a/configure.in b/configure.in
index eaf1afe..444528c 100644
--- a/configure.in
+++ b/configure.in
@@ -142,6 +142,10 @@
LDFLAGS="$LDFLAGS $(pkg-config --libs openssl)";
CFLAGS="$CFLAGS $(pkg-config --cflags openssl)";
+ AC_CHECK_LIB([dl], [dlopen], [],
+ [AC_MSG_FAILURE([can't find libdl])])
+ AC_CHECK_LIB([z], [inflate], [],
+ [AC_MSG_FAILURE([can't find libz])])
AC_CHECK_LIB([crypto], [EVP_EncryptInit], [],
[AC_MSG_FAILURE([can't find openssl >1.0.1 crypto lib])])
AC_CHECK_LIB([crypto], [EVP_aes_128_ctr], [],