bug#34937: [PATCH] update user docs for emacs-gnutls; tofu and program vs built-in

[Tara Sawyer <tara@anne.cat>]

---
 doc/misc/emacs-gnutls.texi | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/doc/misc/emacs-gnutls.texi b/doc/misc/emacs-gnutls.texi
index add79d12e4..e79174d784 100644
--- a/doc/misc/emacs-gnutls.texi
+++ b/doc/misc/emacs-gnutls.texi
@@ -93,6 +93,24 @@ There's one way to find out if GnuTLS is available, by calling
 @url{http://sourceforge.net/projects/ezwinports/files/} thanks to Eli
 Zaretskii) in the same directory as Emacs, you should be OK.
 
+To debug GnuTLS problems, first check the messages buffer, and then
+check the function below @code{gnutls-log-level}
+
+If GnuTLS is not available as a built-in (@code{gnutls-available-p}
+returns an empty list (), emacs will call out to the @code{gnutls-cli}
+program to perform TLS connections.  If you need to modify
+the command it calls you can do this with the variable
+@code{tls-program}.
+For example, if you want to pin a certificate and use Trust On First
+Use(TOFU), then something like this:
+ @code{(add-to-list 'tls-program "gnutls-cli --tofu --x509cafile %t -p
+ %p %h ")}
+ will probably serve you well.
+
+
+
+@section Functions and Variables
+
 @defun gnutls-available-p
 This function returns non-@code{nil} if GnuTLS is available in this
 instance of Emacs, @code{nil} otherwise.  If GnuTLS is available, the
-- 
2.21.0