fixes #1206 Document TLS engine support

1 files changed, 51 insertions, 0 deletions

diff --git a/docs/man/nng_tls_engine_fips_mode.3tls.adoc b/docs/man/nng_tls_engine_fips_mode.3tls.adoc
new file mode 100644
index 00000000..68aaef2c
--- /dev/null
+++ b/docs/man/nng_tls_engine_fips_mode.3tls.adoc
@@ -0,0 +1,51 @@
+= nng_tls_fips_mode(3tls)
+//
+// Copyright 2020 Staysail Systems, Inc. <info@staysail.tech>
+//
+// This document is supplied under the terms of the MIT License, a
+// copy of which should be located in the distribution where this
+// file was obtained (LICENSE.txt).  A copy of the license may also be
+// found online at https://opensource.org/licenses/MIT.
+//
+
+== NAME
+
+nng_tls_engine_fips_mode - TLS FIPS 140-2 mode indicator
+
+== SYNOPSIS
+
+[source,c]
+----
+#include <nng/supplemental/tls/tls.h>
+
+bool nng_tls_engine_fips_mode(void);
+----
+
+== DESCRIPTION
+
+The `nng_tls_engine_fips_mode()` returns `true` if the
+xref:tls_engine.5.adoc[TLS engine] is operating in FIPS 140-2 mode,
+and `false` otherwise.
+
+TIP: FIPS 140-2 references a United States standard for the use
+of cryptography in information processing systems.
+
+TIP: The default TLS engine does not support FIPS 140-2 mode, and
+will always return false.  Alternative implementations with such
+support may be available from commercial suppliers.
+
+NOTE: Generally the FIPS 140-2 mode cannot be changed after program startup.
+
+== RETURN VALUES
+
+True if the TLS engine is in FIPS 140-2 mode, false otherwise.
+
+== ERRORS
+
+None.
+
+== SEE ALSO
+
+[.text-left]
+xref:nng_tls_engine.5.adoc[nng_tls_engine(5)],
+xref:nng.7.adoc[nng(7)]