CURLINFO_TLS_SESSION: always return backend info

... even for those that don't support providing anything in the
'internals' struct member since it offers a convenient way for
applications to figure this out.

1 files changed, 10 insertions, 2 deletions

diff --git a/docs/libcurl/opts/CURLINFO_TLS_SESSION.3 b/docs/libcurl/opts/CURLINFO_TLS_SESSION.3
index 52dd8ad48..868ba73d8 100644
--- a/docs/libcurl/opts/CURLINFO_TLS_SESSION.3
+++ b/docs/libcurl/opts/CURLINFO_TLS_SESSION.3
@@ -38,8 +38,8 @@ internal TLS session structure of this underlying SSL library.
 This may then be used to extract certificate information in a format
 convenient for further processing, such as manual validation. NOTE: this
 option may not be available for all SSL backends; unsupported SSL backends
-will return 'CURLSSLBACKEND_NONE' to indicate that they are not supported;
-this does not mean that no SSL backend was used.
+will always return NULL in the \fIinternals\fP pointer to indicate that they
+are not supported.
 
 .nf
 struct curl_tlssessioninfo {
@@ -48,6 +48,14 @@ struct curl_tlssessioninfo {
 };
 .fi
 
+The \fIbackend\fP struct member is one of the defines in the CURLSSLBACKEND_*
+series: CURLSSLBACKEND_NONE (when built without TLS support),
+CURLSSLBACKEND_OPENSSL, CURLSSLBACKEND_GNUTLS, CURLSSLBACKEND_NSS,
+CURLSSLBACKEND_GSKIT, CURLSSLBACKEND_POLARSSL, CURLSSLBACKEND_CYASSL,
+CURLSSLBACKEND_SCHANNEL, CURLSSLBACKEND_DARWINSSL or
+CURLSSLBACKEND_AXTLS. (Note that the OpenSSL forks are all reported as just
+OpenSSL here.)
+
 The \fIinternals\fP struct member will point to a TLS library specific pointer
 with the following underlying types:
 .RS