crypto/tls: expand docs on client-side session ticket support

Users are sometimes confused why session tickets are not enabled even if
SessionTicketsDisabled is false.

Change-Id: I3b783d2cf3eed693a3ad6acb40a8003db7e0b648
Reviewed-on: https://go-review.googlesource.com/117255
Reviewed-by: Adam Langley <agl@golang.org>

diff --git a/src/crypto/tls/common.go b/src/crypto/tls/common.go
index 76b1f6e5c4b37211dc1652bccb2e760bca71035a..423787b415e05656fe33561ebd4c8cfaeaf05bbc 100644 (file)
--- a/src/crypto/tls/common.go
+++ b/src/crypto/tls/common.go
@@ -459,7 +459,8 @@ type Config struct {
        PreferServerCipherSuites bool
 
        // SessionTicketsDisabled may be set to true to disable session ticket
-       // (resumption) support.
+       // (resumption) support. Note that on clients, session ticket support is
+       // also disabled if ClientSessionCache is nil.
        SessionTicketsDisabled bool
 
        // SessionTicketKey is used by TLS servers to provide session
@@ -473,7 +474,7 @@ type Config struct {
        SessionTicketKey [32]byte
 
        // ClientSessionCache is a cache of ClientSessionState entries for TLS
-       // session resumption.
+       // session resumption. It is only used by clients.
        ClientSessionCache ClientSessionCache
 
        // MinVersion contains the minimum SSL/TLS version that is acceptable.