From 576e507c78bdd2ec88da442a5354f9dd661b9a8a Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Thu, 25 Aug 2022 17:29:48 +0200
Subject: [PATCH] configure: if asked to use TLS, fail if no TLS lib was
 detected

Previously the configure script would just warn about this fact and
continue with TLS disabled build which is not always helpful. TLS should
be explicitly disabled if that is what the user wants.

Closes #9367
---
 configure.ac | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/configure.ac b/configure.ac
index 7d5750c922..30c881f3fc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -218,6 +218,8 @@ AS_HELP_STRING([--without-ssl], [build without any TLS library]),[
   OPT_OPENSSL=$withval
   if test X"$withval" != Xno; then
     TLSCHOICE="${TLSCHOICE:+$TLSCHOICE, }OpenSSL"
+  else
+    SSL_DISABLED="D"
   fi
 ])
 
@@ -1955,11 +1957,11 @@ if test "x$curl_cv_native_windows" = "xyes" &&
   LIBS="-lbcrypt $LIBS"
 fi
 
-case "x$OPENSSL_ENABLED$GNUTLS_ENABLED$NSS_ENABLED$MBEDTLS_ENABLED$WOLFSSL_ENABLED$SCHANNEL_ENABLED$SECURETRANSPORT_ENABLED$BEARSSL_ENABLED$RUSTLS_ENABLED"
+case "x$OPENSSL_ENABLED$GNUTLS_ENABLED$NSS_ENABLED$MBEDTLS_ENABLED$WOLFSSL_ENABLED$SCHANNEL_ENABLED$SECURETRANSPORT_ENABLED$BEARSSL_ENABLED$RUSTLS_ENABLED$SSL_DISABLED"
 in
 x)
-  AC_MSG_WARN([SSL disabled, you will not be able to use HTTPS, FTPS, NTLM and more.])
-  AC_MSG_WARN([Use --with-openssl, --with-gnutls, --with-wolfssl, --with-mbedtls, --with-nss, --with-schannel, --with-secure-transport, --with-amissl, --with-bearssl or --with-rustls to address this.])
+  AC_MSG_ERROR([TLS not detected, you will not be able to use HTTPS, FTPS, NTLM and more.
+Use --with-openssl, --with-gnutls, --with-wolfssl, --with-mbedtls, --with-nss, --with-schannel, --with-secure-transport, --with-amissl, --with-bearssl or --with-rustls to address this.])
   ;;
 x1)
   # one SSL backend is enabled
@@ -1967,6 +1969,9 @@ x1)
   SSL_ENABLED="1"
   AC_MSG_NOTICE([built with one SSL backend])
   ;;
+xD)
+  # explicitly built without TLS
+  ;;
 *)
   # more than one SSL backend is enabled
   AC_SUBST(SSL_ENABLED)