crypto/tls: persist the createdAt time when re-wrapping session tickets

Change-Id: I33fcde2d544943fb04c2599810cf7fb773aeba1f
Reviewed-on: https://go-review.googlesource.com/c/go/+/234483
Run-TryBot: Katie Hockman <katie@golang.org>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

diff --git a/src/crypto/tls/handshake_client_test.go b/src/crypto/tls/handshake_client_test.go
index 313872ca76c6d37dc8ceedbece479b02c666833a..de93e1b63f3a92c36b815a8a624b1545a0e01128 100644 (file)
--- a/src/crypto/tls/handshake_client_test.go
+++ b/src/crypto/tls/handshake_client_test.go
@@ -980,7 +980,28 @@ func testResumption(t *testing.T, version uint16) {
        if bytes.Equal(ticket, getTicket()) {
                t.Fatal("new ticket wasn't provided after old ticket expired")
        }
-       testResumeState("FreshSessionTicket", true)
+
+       // Age the session ticket a bit at a time, but don't expire it.
+       d := 0 * time.Hour
+       for i := 0; i < 13; i++ {
+               d += 12 * time.Hour
+               serverConfig.Time = func() time.Time { return time.Now().Add(d) }
+               testResumeState("OldSessionTicket", true)
+       }
+       // Expire it (now a little more than 7 days) and make sure a full
+       // handshake occurs for TLS 1.2. Resumption should still occur for
+       // TLS 1.3 since the client should be using a fresh ticket sent over
+       // by the server.
+       d += 12 * time.Hour
+       serverConfig.Time = func() time.Time { return time.Now().Add(d) }
+       if version == VersionTLS13 {
+               testResumeState("ExpiredSessionTicket", true)
+       } else {
+               testResumeState("ExpiredSessionTicket", false)
+       }
+       if bytes.Equal(ticket, getTicket()) {
+               t.Fatal("new ticket wasn't provided after old ticket expired")
+       }
 
        // Reset serverConfig to ensure that calling SetSessionTicketKeys
        // before the serverConfig is used works.

diff --git a/src/crypto/tls/handshake_server.go b/src/crypto/tls/handshake_server.go
index 6aacfa1ff6622c364f1573ac3c9fd3a218ed68a2..57fba108a72420a8ec5570c08d9221789a0c54be 100644 (file)
--- a/src/crypto/tls/handshake_server.go
+++ b/src/crypto/tls/handshake_server.go
@@ -75,13 +75,8 @@ func (hs *serverHandshakeState) handshake() error {
                if err := hs.establishKeys(); err != nil {
                        return err
                }
-               // ticketSupported is set in a resumption handshake if the
-               // ticket from the client was encrypted with an old session
-               // ticket key and thus a refreshed ticket should be sent.
-               if hs.hello.ticketSupported {
-                       if err := hs.sendSessionTicket(); err != nil {
-                               return err
-                       }
+               if err := hs.sendSessionTicket(); err != nil {
+                       return err
                }
                if err := hs.sendFinished(c.serverFinished[:]); err != nil {
                        return err
@@ -688,6 +683,9 @@ func (hs *serverHandshakeState) readFinished(out []byte) error {
 }
 
 func (hs *serverHandshakeState) sendSessionTicket() error {
+       // ticketSupported is set in a resumption handshake if the
+       // ticket from the client was encrypted with an old session
+       // ticket key and thus a refreshed ticket should be sent.
        if !hs.hello.ticketSupported {
                return nil
        }
@@ -695,6 +693,13 @@ func (hs *serverHandshakeState) sendSessionTicket() error {
        c := hs.c
        m := new(newSessionTicketMsg)
 
+       createdAt := uint64(c.config.time().Unix())
+       if hs.sessionState != nil {
+               // If this is re-wrapping an old key, then keep
+               // the original time it was created.
+               createdAt = hs.sessionState.createdAt
+       }
+
        var certsFromClient [][]byte
        for _, cert := range c.peerCertificates {
                certsFromClient = append(certsFromClient, cert.Raw)
@@ -702,7 +707,7 @@ func (hs *serverHandshakeState) sendSessionTicket() error {
        state := sessionState{
                vers:         c.vers,
                cipherSuite:  hs.suite.id,
-               createdAt:    uint64(c.config.time().Unix()),
+               createdAt:    createdAt,
                masterSecret: hs.masterSecret,
                certificates: certsFromClient,
        }