On Wed, Jul 18, 2012 at 09:43:38PM +0100, David Woodhouse wrote:
> Newer versions of GnuTLS (3.0.20+) have a function which adds the
> "system" trust file, gnutls_certificate_set_x509_system_trust(). But
> your GnuTLS is older than that, so the OpenConnect code just falls back
> to adding /etc/pki/tls/certs/ca-bundle.crt manually. And that isn't
> where it is on your distribution.
>
> I suppose we ought to add some magic in the configure script to *find*
> the file in the appropriate location. In the meantime, Mike may wish to
> patch it to change the hard-coded location. Sorry, I knew that was wrong
> when I did it, but it was part of the *first* commit adding GnuTLS
> support (which didn't actually use it to do any verification yet anyway)
> and I meant to come back to revisit it... but forgot.
Good catch both of you, I'll fix my Debian and Ubuntu builds to use the
correct ca-certificates path.
So how about something like this for the configure script? Could
probably use some polishing but I think it's functionally correct.
>From a460a7672f6a011b54e5ffc60bc8372ed9a43d0e Mon Sep 17 00:00:00 2001
From: Mike Miller <mtmiller at ieee.org>
Date: Thu, 19 Jul 2012 00:47:32 -0400
Subject: [PATCH] Check for system CA certificate file for GnuTLS
Look in certain well-known system paths for the default file to give to
gnutls_certificate_set_x509_trust_file() if required. Auto-detection is
based on the GnuTLS configure script.
Signed-off-by: Mike Miller <mtmiller at ieee.org>
---
configure.ac | 32 ++++++++++++++++++++++++++++++++
gnutls.c | 2 +-
2 files changed, 33 insertions(+), 1 deletion(-)
diff --git a/configure.ac b/configure.ac
index c067276..30ed5c8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -179,6 +179,10 @@ if test "$USE_NLS" = "yes"; then
fi
AM_CONDITIONAL(USE_NLS, [test "$USE_NLS" = "yes"])
+AC_ARG_WITH([system-cafile],
+ AS_HELP_STRING([--with-system-cafile],
+ [Location of the default system CA certificate file]))
+
# We will use GnuTLS if it's requested, and if GnuTLS doesn't have DTLS
# support then we'll *also* use OpenSSL for that, but it appears *only*
# only in the openconnect executable and not the library (hence shouldn't
@@ -209,6 +213,34 @@ if test "$with_gnutls" = "yes"; then
[AC_DEFINE(HAVE_GNUTLS_DTLS_SET_DATA_MTU, 1)], [])
AC_CHECK_FUNC(gnutls_certificate_set_x509_system_trust,
[AC_DEFINE(HAVE_GNUTLS_CERTIFICATE_SET_X509_SYSTEM_TRUST, 1)], [])
+ if test "$ac_cv_func_gnutls_certificate_set_x509_system_trust" != "yes"; then
+ # We will need to tell GnuTLS the path to the system CA file.
+ if test "$with_system_cafile" = "yes" || test "$with_system_cafile" = ""; then
+ # Auto-detect path to the system CA file, based on GnuTLS.
+ with_system_cafile=
+ for i in \
+ /etc/ssl/certs/ca-certificates.crt \
+ /etc/pki/tls/cert.pem \
+ /usr/local/share/certs/ca-root-nss.crt
+ do
+ if test -e $i; then
+ with_system_cafile="$i"
+ break
+ fi
+ done
+ elif test "$with_system_cafile" = "no"; then
+ AC_MSG_ERROR([You cannot disable the system CA certificate file.])
+ fi
+ if test "$with_system_cafile" = ""; then
+ AC_MSG_ERROR([Unable to find a standard system CA certificate file.]
+ [Your GnuTLS requires a path to a CA certificate store. Most distributions]
+ [ship with a CA certificate file in a standard location. None of the known]
+ [standard locations exist on your system. You should provide a]
+ [--with-system-cafile= argument to this configure script, giving the full]
+ [path to a default CA certificate file for GnuTLS to use.])
+ fi
+ AC_DEFINE_UNQUOTED([DEFAULT_SYSTEM_CAFILE], ["$with_system_cafile"])
+ fi
AC_CHECK_FUNC(gnutls_pkcs12_simple_parse,
[AC_DEFINE(HAVE_GNUTLS_PKCS12_SIMPLE_PARSE, 1)], [])
AC_CHECK_FUNC(gnutls_certificate_set_key,
diff --git a/gnutls.c b/gnutls.c
index 42f709a..d9e550d 100644
--- a/gnutls.c
+++ b/gnutls.c
@@ -1751,7 +1751,7 @@ int openconnect_open_https(struct openconnect_info *vpninfo)
gnutls_certificate_set_x509_system_trust(vpninfo->https_cred);
#else
gnutls_certificate_set_x509_trust_file(vpninfo->https_cred,
- "/etc/pki/tls/certs/ca-bundle.crt",
+ DEFAULT_SYSTEM_CAFILE,
GNUTLS_X509_FMT_PEM);
#endif
gnutls_certificate_set_verify_function (vpninfo->https_cred,
--
1.7.10.4
