[release-branch.go1.26] crypto/tls: check verifiedChains roots when resuming sessions

When resuming TLS sessions, on the server and client verify that the
chains stored in the session state (verifiedChains) are still acceptable
with regards to the Config by checking for the inclusion of the root in
either ClientCAs (server) or RootCAs (client). This prevents resuming
a session with a certificate chain that would be rejected during a full
handshake due to an untrusted root.

Updates #77113
Updates #77357
Updates CVE-2025-68121

Change-Id: I11fe00909ef1961c24ecf80bf5b97f7b1121d359
Reviewed-on: https://go-review.googlesource.com/c/go/+/737700
Auto-Submit: Roland Shoemaker <roland@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Coia Prant <coiaprant@gmail.com>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Reviewed-on: https://go-review.googlesource.com/c/go/+/740004
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Nicholas Husin <husin@google.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Nicholas Husin <nsh@golang.org>

VERSION

@@ -0,0 +1,2 @@
+go1.26rc2
+time 2026-01-08T21:54:29Z

codereview.cfg

@@ -1 +1,2 @@
-branch: master
+branch: release-branch.go1.26
+parent-branch: master

src/cmd/compile/internal/ssa/_gen/simdAMD64ops.go

@@ -28,16 +28,16 @@ func simdAMD64Ops(v11, v21, v2k, vkv, v2kv, v2kk, v31, v3kv, vgpv, vgp, vfpv, vf
 		{name: "VADDSUBPS128", argLength: 2, reg: v21, asm: "VADDSUBPS", commutative: false, typ: "Vec128", resultInArg0: false},
 		{name: "VADDSUBPS256", argLength: 2, reg: v21, asm: "VADDSUBPS", commutative: false, typ: "Vec256", resultInArg0: false},
 		{name: "VAESDEC128", argLength: 2, reg: v21, asm: "VAESDEC", commutative: false, typ: "Vec128", resultInArg0: false},
-		{name: "VAESDEC256", argLength: 2, reg: w21, asm: "VAESDEC", commutative: false, typ: "Vec256", resultInArg0: false},
+		{name: "VAESDEC256", argLength: 2, reg: v21, asm: "VAESDEC", commutative: false, typ: "Vec256", resultInArg0: false},
 		{name: "VAESDEC512", argLength: 2, reg: w21, asm: "VAESDEC", commutative: false, typ: "Vec512", resultInArg0: false},
 		{name: "VAESDECLAST128", argLength: 2, reg: v21, asm: "VAESDECLAST", commutative: false, typ: "Vec128", resultInArg0: false},
-		{name: "VAESDECLAST256", argLength: 2, reg: w21, asm: "VAESDECLAST", commutative: false, typ: "Vec256", resultInArg0: false},
+		{name: "VAESDECLAST256", argLength: 2, reg: v21, asm: "VAESDECLAST", commutative: false, typ: "Vec256", resultInArg0: false},
 		{name: "VAESDECLAST512", argLength: 2, reg: w21, asm: "VAESDECLAST", commutative: false, typ: "Vec512", resultInArg0: false},
 		{name: "VAESENC128", argLength: 2, reg: v21, asm: "VAESENC", commutative: false, typ: "Vec128", resultInArg0: false},
-		{name: "VAESENC256", argLength: 2, reg: w21, asm: "VAESENC", commutative: false, typ: "Vec256", resultInArg0: false},
+		{name: "VAESENC256", argLength: 2, reg: v21, asm: "VAESENC", commutative: false, typ: "Vec256", resultInArg0: false},
 		{name: "VAESENC512", argLength: 2, reg: w21, asm: "VAESENC", commutative: false, typ: "Vec512", resultInArg0: false},
 		{name: "VAESENCLAST128", argLength: 2, reg: v21, asm: "VAESENCLAST", commutative: false, typ: "Vec128", resultInArg0: false},
-		{name: "VAESENCLAST256", argLength: 2, reg: w21, asm: "VAESENCLAST", commutative: false, typ: "Vec256", resultInArg0: false},
+		{name: "VAESENCLAST256", argLength: 2, reg: v21, asm: "VAESENCLAST", commutative: false, typ: "Vec256", resultInArg0: false},
 		{name: "VAESENCLAST512", argLength: 2, reg: w21, asm: "VAESENCLAST", commutative: false, typ: "Vec512", resultInArg0: false},
 		{name: "VAESIMC128", argLength: 1, reg: v11, asm: "VAESIMC", commutative: false, typ: "Vec128", resultInArg0: false},
 		{name: "VBROADCASTSD256", argLength: 1, reg: v11, asm: "VBROADCASTSD", commutative: false, typ: "Vec256", resultInArg0: false},

src/cmd/compile/internal/ssa/opGen.go

@@ -21199,11 +21199,11 @@ var opcodeTable = [...]opInfo{
 		asm:    x86.AVAESDEC,
 		reg: regInfo{
 			inputs: []inputInfo{
-				{0, 281474976645120}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X15 X16 X17 X18 X19 X20 X21 X22 X23 X24 X25 X26 X27 X28 X29 X30 X31
-				{1, 281474976645120}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X15 X16 X17 X18 X19 X20 X21 X22 X23 X24 X25 X26 X27 X28 X29 X30 X31
+				{0, 2147418112}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14
+				{1, 4294901760}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X15
 			},
 			outputs: []outputInfo{
-				{0, 281472829161472}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X16 X17 X18 X19 X20 X21 X22 X23 X24 X25 X26 X27 X28 X29 X30 X31
+				{0, 2147418112}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14
 			},
 		},
 	},
@@ -21241,11 +21241,11 @@ var opcodeTable = [...]opInfo{
 		asm:    x86.AVAESDECLAST,
 		reg: regInfo{
 			inputs: []inputInfo{
-				{0, 281474976645120}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X15 X16 X17 X18 X19 X20 X21 X22 X23 X24 X25 X26 X27 X28 X29 X30 X31
-				{1, 281474976645120}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X15 X16 X17 X18 X19 X20 X21 X22 X23 X24 X25 X26 X27 X28 X29 X30 X31
+				{0, 2147418112}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14
+				{1, 4294901760}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X15
 			},
 			outputs: []outputInfo{
-				{0, 281472829161472}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X16 X17 X18 X19 X20 X21 X22 X23 X24 X25 X26 X27 X28 X29 X30 X31
+				{0, 2147418112}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14
 			},
 		},
 	},
@@ -21283,11 +21283,11 @@ var opcodeTable = [...]opInfo{
 		asm:    x86.AVAESENC,
 		reg: regInfo{
 			inputs: []inputInfo{
-				{0, 281474976645120}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X15 X16 X17 X18 X19 X20 X21 X22 X23 X24 X25 X26 X27 X28 X29 X30 X31
-				{1, 281474976645120}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X15 X16 X17 X18 X19 X20 X21 X22 X23 X24 X25 X26 X27 X28 X29 X30 X31
+				{0, 2147418112}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14
+				{1, 4294901760}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X15
 			},
 			outputs: []outputInfo{
-				{0, 281472829161472}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X16 X17 X18 X19 X20 X21 X22 X23 X24 X25 X26 X27 X28 X29 X30 X31
+				{0, 2147418112}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14
 			},
 		},
 	},
@@ -21325,11 +21325,11 @@ var opcodeTable = [...]opInfo{
 		asm:    x86.AVAESENCLAST,
 		reg: regInfo{
 			inputs: []inputInfo{
-				{0, 281474976645120}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X15 X16 X17 X18 X19 X20 X21 X22 X23 X24 X25 X26 X27 X28 X29 X30 X31
-				{1, 281474976645120}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X15 X16 X17 X18 X19 X20 X21 X22 X23 X24 X25 X26 X27 X28 X29 X30 X31
+				{0, 2147418112}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14
+				{1, 4294901760}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X15
 			},
 			outputs: []outputInfo{
-				{0, 281472829161472}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X16 X17 X18 X19 X20 X21 X22 X23 X24 X25 X26 X27 X28 X29 X30 X31
+				{0, 2147418112}, // X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14
 			},
 		},
 	},

src/crypto/tls/common.go

@@ -980,10 +980,6 @@ const maxSessionTicketLifetime = 7 * 24 * time.Hour
 
 // Clone returns a shallow clone of c or nil if c is nil. It is safe to clone a [Config] that is
 // being used concurrently by a TLS client or server.
-//
-// If Config.SessionTicketKey is unpopulated, and Config.SetSessionTicketKeys has not been
-// called, the clone will not share the same auto-rotated session ticket keys as the original
-// Config in order to prevent sessions from being resumed across Configs.
 func (c *Config) Clone() *Config {
 	if c == nil {
 		return nil
@@ -1024,8 +1020,7 @@ func (c *Config) Clone() *Config {
 		EncryptedClientHelloRejectionVerify: c.EncryptedClientHelloRejectionVerify,
 		EncryptedClientHelloKeys:            c.EncryptedClientHelloKeys,
 		sessionTicketKeys:                   c.sessionTicketKeys,
-		// We explicitly do not copy autoSessionTicketKeys, so that Configs do
-		// not share the same auto-rotated keys.
+		autoSessionTicketKeys:               c.autoSessionTicketKeys,
 	}
 }
 
@@ -1851,3 +1846,31 @@ func fipsAllowChain(chain []*x509.Certificate) bool {
 
 	return true
 }
+
+// anyValidVerifiedChain reports if at least one of the chains in verifiedChains
+// is valid, as indicated by none of the certificates being expired and the root
+// being in opts.Roots (or in the system root pool if opts.Roots is nil). If
+// verifiedChains is empty, it returns false.
+func anyValidVerifiedChain(verifiedChains [][]*x509.Certificate, opts x509.VerifyOptions) bool {
+	for _, chain := range verifiedChains {
+		if len(chain) == 0 {
+			continue
+		}
+		if slices.ContainsFunc(chain, func(cert *x509.Certificate) bool {
+			return opts.CurrentTime.Before(cert.NotBefore) || opts.CurrentTime.After(cert.NotAfter)
+		}) {
+			continue
+		}
+		// Since we already validated the chain, we only care that it is
+		// rooted in a CA in CAs, or in the system pool. On platforms where
+		// we control chain validation (e.g. not Windows or macOS) this is a
+		// simple lookup in the CertPool internal hash map. On other
+		// platforms, this may be more expensive, depending on how they
+		// implement verification of just root certificates.
+		root := chain[len(chain)-1]
+		if _, err := root.Verify(opts); err == nil {
+			return true
+		}
+	}
+	return false
+}

src/crypto/tls/handshake_client.go

@@ -397,9 +397,6 @@ func (c *Conn) loadSession(hello *clientHelloMsg) (
 		return nil, nil, nil, nil
 	}
 
-	// Check that the cached server certificate is not expired, and that it's
-	// valid for the ServerName. This should be ensured by the cache key, but
-	// protect the application from a faulty ClientSessionCache implementation.
 	if c.config.time().After(session.peerCertificates[0].NotAfter) {
 		// Expired certificate, delete the entry.
 		c.config.ClientSessionCache.Put(cacheKey, nil)
@@ -411,6 +408,18 @@ func (c *Conn) loadSession(hello *clientHelloMsg) (
 			return nil, nil, nil, nil
 		}
 		if err := session.peerCertificates[0].VerifyHostname(c.config.ServerName); err != nil {
+			// This should be ensured by the cache key, but protect the
+			// application from a faulty ClientSessionCache implementation.
+			return nil, nil, nil, nil
+		}
+		opts := x509.VerifyOptions{
+			CurrentTime: c.config.time(),
+			Roots:       c.config.RootCAs,
+			KeyUsages:   []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
+		}
+		if !anyValidVerifiedChain(session.verifiedChains, opts) {
+			// No valid chains, delete the entry.
+			c.config.ClientSessionCache.Put(cacheKey, nil)
 			return nil, nil, nil, nil
 		}
 	}

src/crypto/tls/handshake_server.go

@@ -520,16 +520,16 @@ func (hs *serverHandshakeState) checkForResumption() error {
 	if sessionHasClientCerts && c.config.ClientAuth == NoClientCert {
 		return nil
 	}
-	if sessionHasClientCerts {
-		now := c.config.time()
-		for _, c := range sessionState.peerCertificates {
-			if now.After(c.NotAfter) {
-				return nil
-			}
-		}
+	if sessionHasClientCerts && c.config.time().After(sessionState.peerCertificates[0].NotAfter) {
+		return nil
+	}
+	opts := x509.VerifyOptions{
+		CurrentTime: c.config.time(),
+		Roots:       c.config.ClientCAs,
+		KeyUsages:   []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth},
 	}
 	if sessionHasClientCerts && c.config.ClientAuth >= VerifyClientCertIfGiven &&
-		len(sessionState.verifiedChains) == 0 {
+		!anyValidVerifiedChain(sessionState.verifiedChains, opts) {
 		return nil
 	}
 

src/crypto/tls/handshake_server_test.go

@@ -2155,7 +2155,7 @@ func TestHandshakeContextHierarchy(t *testing.T) {
 	}
 }
 
-func TestHandshakeChainExpiryResumptionTLS12(t *testing.T) {
+func TestHandshakeChainExpiryResumption(t *testing.T) {
 	t.Run("TLS1.2", func(t *testing.T) {
 		testHandshakeChainExpiryResumption(t, VersionTLS12)
 	})
@@ -2166,7 +2166,8 @@ func TestHandshakeChainExpiryResumptionTLS12(t *testing.T) {
 
 func testHandshakeChainExpiryResumption(t *testing.T, version uint16) {
 	now := time.Now()
-	createChain := func(leafNotAfter, rootNotAfter time.Time) (certDER []byte, root *x509.Certificate) {
+
+	createChain := func(leafNotAfter, rootNotAfter time.Time) (leafDER, expiredLeafDER []byte, root *x509.Certificate) {
 		tmpl := &x509.Certificate{
 			Subject:               pkix.Name{CommonName: "root"},
 			NotBefore:             rootNotAfter.Add(-time.Hour * 24),
@@ -2190,39 +2191,177 @@ func testHandshakeChainExpiryResumption(t *testing.T, version uint16) {
 			NotAfter:  leafNotAfter,
 			KeyUsage:  x509.KeyUsageDigitalSignature,
 		}
-		certDER, err = x509.CreateCertificate(rand.Reader, tmpl, root, &testECDSAPrivateKey.PublicKey, testECDSAPrivateKey)
+		leafCertDER, err := x509.CreateCertificate(rand.Reader, tmpl, root, &testECDSAPrivateKey.PublicKey, testECDSAPrivateKey)
+		if err != nil {
+			t.Fatalf("CreateCertificate: %v", err)
+		}
+		tmpl.NotBefore, tmpl.NotAfter = leafNotAfter.Add(-time.Hour*24*365), leafNotAfter.Add(-time.Hour*24*364)
+		expiredLeafDERCertDER, err := x509.CreateCertificate(rand.Reader, tmpl, root, &testECDSAPrivateKey.PublicKey, testECDSAPrivateKey)
 		if err != nil {
 			t.Fatalf("CreateCertificate: %v", err)
 		}
 
-		return certDER, root
+		return leafCertDER, expiredLeafDERCertDER, root
+	}
+	testExpiration := func(name string, leafNotAfter, rootNotAfter time.Time) {
+		t.Run(name, func(t *testing.T) {
+			initialLeafDER, expiredLeafDER, initialRoot := createChain(leafNotAfter, rootNotAfter)
+
+			serverConfig := testConfig.Clone()
+			serverConfig.MaxVersion = version
+			serverConfig.Certificates = []Certificate{{
+				Certificate: [][]byte{initialLeafDER, expiredLeafDER},
+				PrivateKey:  testECDSAPrivateKey,
+			}}
+			serverConfig.ClientCAs = x509.NewCertPool()
+			serverConfig.ClientCAs.AddCert(initialRoot)
+			serverConfig.ClientAuth = RequireAndVerifyClientCert
+			serverConfig.Time = func() time.Time {
+				return now
+			}
+			serverConfig.InsecureSkipVerify = false
+			serverConfig.ServerName = "expired-resume.example.com"
+
+			clientConfig := testConfig.Clone()
+			clientConfig.MaxVersion = version
+			clientConfig.Certificates = []Certificate{{
+				Certificate: [][]byte{initialLeafDER, expiredLeafDER},
+				PrivateKey:  testECDSAPrivateKey,
+			}}
+			clientConfig.RootCAs = x509.NewCertPool()
+			clientConfig.RootCAs.AddCert(initialRoot)
+			clientConfig.ServerName = "expired-resume.example.com"
+			clientConfig.ClientSessionCache = NewLRUClientSessionCache(32)
+			clientConfig.InsecureSkipVerify = false
+			clientConfig.ServerName = "expired-resume.example.com"
+			clientConfig.Time = func() time.Time {
+				return now
+			}
+
+			testResume := func(t *testing.T, sc, cc *Config, expectResume bool) {
+				t.Helper()
+				ss, cs, err := testHandshake(t, cc, sc)
+				if err != nil {
+					t.Fatalf("handshake: %v", err)
+				}
+				if cs.DidResume != expectResume {
+					t.Fatalf("DidResume = %v; want %v", cs.DidResume, expectResume)
+				}
+				if ss.DidResume != expectResume {
+					t.Fatalf("DidResume = %v; want %v", cs.DidResume, expectResume)
+				}
+			}
+
+			testResume(t, serverConfig, clientConfig, false)
+			testResume(t, serverConfig, clientConfig, true)
+
+			expiredNow := time.Unix(0, min(leafNotAfter.UnixNano(), rootNotAfter.UnixNano())).Add(time.Minute)
+
+			freshLeafDER, expiredLeafDER, freshRoot := createChain(expiredNow.Add(time.Hour), expiredNow.Add(time.Hour))
+			clientConfig.Certificates = []Certificate{{
+				Certificate: [][]byte{freshLeafDER, expiredLeafDER},
+				PrivateKey:  testECDSAPrivateKey,
+			}}
+			serverConfig.Time = func() time.Time {
+				return expiredNow
+			}
+			serverConfig.ClientCAs = x509.NewCertPool()
+			serverConfig.ClientCAs.AddCert(freshRoot)
+
+			testResume(t, serverConfig, clientConfig, false)
+		})
 	}
 
-	initialLeafDER, initialRoot := createChain(now.Add(time.Hour), now.Add(2*time.Hour))
+	testExpiration("LeafExpiresBeforeRoot", now.Add(2*time.Hour), now.Add(3*time.Hour))
+	testExpiration("LeafExpiresAfterRoot", now.Add(2*time.Hour), now.Add(time.Hour))
+}
+
+func TestHandshakeGetConfigForClientDifferentClientCAs(t *testing.T) {
+	t.Run("TLS1.2", func(t *testing.T) {
+		testHandshakeGetConfigForClientDifferentClientCAs(t, VersionTLS12)
+	})
+	t.Run("TLS1.3", func(t *testing.T) {
+		testHandshakeGetConfigForClientDifferentClientCAs(t, VersionTLS13)
+	})
+}
+
+func testHandshakeGetConfigForClientDifferentClientCAs(t *testing.T, version uint16) {
+	now := time.Now()
+	tmpl := &x509.Certificate{
+		Subject:               pkix.Name{CommonName: "root"},
+		NotBefore:             now.Add(-time.Hour * 24),
+		NotAfter:              now.Add(time.Hour * 24),
+		IsCA:                  true,
+		BasicConstraintsValid: true,
+	}
+	rootDER, err := x509.CreateCertificate(rand.Reader, tmpl, tmpl, &testECDSAPrivateKey.PublicKey, testECDSAPrivateKey)
+	if err != nil {
+		t.Fatalf("CreateCertificate: %v", err)
+	}
+	rootA, err := x509.ParseCertificate(rootDER)
+	if err != nil {
+		t.Fatalf("ParseCertificate: %v", err)
+	}
+	rootDER, err = x509.CreateCertificate(rand.Reader, tmpl, tmpl, &testECDSAPrivateKey.PublicKey, testECDSAPrivateKey)
+	if err != nil {
+		t.Fatalf("CreateCertificate: %v", err)
+	}
+	rootB, err := x509.ParseCertificate(rootDER)
+	if err != nil {
+		t.Fatalf("ParseCertificate: %v", err)
+	}
+
+	tmpl = &x509.Certificate{
+		Subject:   pkix.Name{},
+		DNSNames:  []string{"example.com"},
+		NotBefore: now.Add(-time.Hour * 24),
+		NotAfter:  now.Add(time.Hour * 24),
+		KeyUsage:  x509.KeyUsageDigitalSignature,
+	}
+	certDER, err := x509.CreateCertificate(rand.Reader, tmpl, rootA, &testECDSAPrivateKey.PublicKey, testECDSAPrivateKey)
+	if err != nil {
+		t.Fatalf("CreateCertificate: %v", err)
+	}
 
 	serverConfig := testConfig.Clone()
 	serverConfig.MaxVersion = version
 	serverConfig.Certificates = []Certificate{{
-		Certificate: [][]byte{initialLeafDER},
+		Certificate: [][]byte{certDER},
 		PrivateKey:  testECDSAPrivateKey,
 	}}
-	serverConfig.ClientCAs = x509.NewCertPool()
-	serverConfig.ClientCAs.AddCert(initialRoot)
-	serverConfig.ClientAuth = RequireAndVerifyClientCert
 	serverConfig.Time = func() time.Time {
 		return now
 	}
+	serverConfig.ClientCAs = x509.NewCertPool()
+	serverConfig.ClientCAs.AddCert(rootA)
+	serverConfig.ClientAuth = RequireAndVerifyClientCert
+	switchConfig := false
+	serverConfig.GetConfigForClient = func(clientHello *ClientHelloInfo) (*Config, error) {
+		if !switchConfig {
+			return nil, nil
+		}
+		cfg := serverConfig.Clone()
+		cfg.ClientCAs = x509.NewCertPool()
+		cfg.ClientCAs.AddCert(rootB)
+		return cfg, nil
+	}
+	serverConfig.InsecureSkipVerify = false
+	serverConfig.ServerName = "example.com"
 
 	clientConfig := testConfig.Clone()
 	clientConfig.MaxVersion = version
 	clientConfig.Certificates = []Certificate{{
-		Certificate: [][]byte{initialLeafDER},
+		Certificate: [][]byte{certDER},
 		PrivateKey:  testECDSAPrivateKey,
 	}}
-	clientConfig.RootCAs = x509.NewCertPool()
-	clientConfig.RootCAs.AddCert(initialRoot)
-	clientConfig.ServerName = "expired-resume.example.com"
 	clientConfig.ClientSessionCache = NewLRUClientSessionCache(32)
+	clientConfig.RootCAs = x509.NewCertPool()
+	clientConfig.RootCAs.AddCert(rootA)
+	clientConfig.Time = func() time.Time {
+		return now
+	}
+	clientConfig.InsecureSkipVerify = false
+	clientConfig.ServerName = "example.com"
 
 	testResume := func(t *testing.T, sc, cc *Config, expectResume bool) {
 		t.Helper()
@@ -2241,16 +2380,112 @@ func testHandshakeChainExpiryResumption(t *testing.T, version uint16) {
 	testResume(t, serverConfig, clientConfig, false)
 	testResume(t, serverConfig, clientConfig, true)
 
-	freshLeafDER, freshRoot := createChain(now.Add(2*time.Hour), now.Add(3*time.Hour))
-	clientConfig.Certificates = []Certificate{{
-		Certificate: [][]byte{freshLeafDER},
+	// Cause GetConfigForClient to return a config cloned from the base config,
+	// but with a different ClientCAs pool. This should cause resumption to fail.
+	switchConfig = true
+
+	testResume(t, serverConfig, clientConfig, false)
+	testResume(t, serverConfig, clientConfig, true)
+}
+
+func TestHandshakeChangeRootCAsResumption(t *testing.T) {
+	t.Run("TLS1.2", func(t *testing.T) {
+		testHandshakeChangeRootCAsResumption(t, VersionTLS12)
+	})
+	t.Run("TLS1.3", func(t *testing.T) {
+		testHandshakeChangeRootCAsResumption(t, VersionTLS13)
+	})
+}
+
+func testHandshakeChangeRootCAsResumption(t *testing.T, version uint16) {
+	now := time.Now()
+	tmpl := &x509.Certificate{
+		Subject:               pkix.Name{CommonName: "root"},
+		NotBefore:             now.Add(-time.Hour * 24),
+		NotAfter:              now.Add(time.Hour * 24),
+		IsCA:                  true,
+		BasicConstraintsValid: true,
+	}
+	rootDER, err := x509.CreateCertificate(rand.Reader, tmpl, tmpl, &testECDSAPrivateKey.PublicKey, testECDSAPrivateKey)
+	if err != nil {
+		t.Fatalf("CreateCertificate: %v", err)
+	}
+	rootA, err := x509.ParseCertificate(rootDER)
+	if err != nil {
+		t.Fatalf("ParseCertificate: %v", err)
+	}
+	rootDER, err = x509.CreateCertificate(rand.Reader, tmpl, tmpl, &testECDSAPrivateKey.PublicKey, testECDSAPrivateKey)
+	if err != nil {
+		t.Fatalf("CreateCertificate: %v", err)
+	}
+	rootB, err := x509.ParseCertificate(rootDER)
+	if err != nil {
+		t.Fatalf("ParseCertificate: %v", err)
+	}
+
+	tmpl = &x509.Certificate{
+		Subject:   pkix.Name{},
+		DNSNames:  []string{"example.com"},
+		NotBefore: now.Add(-time.Hour * 24),
+		NotAfter:  now.Add(time.Hour * 24),
+		KeyUsage:  x509.KeyUsageDigitalSignature,
+	}
+	certDER, err := x509.CreateCertificate(rand.Reader, tmpl, rootA, &testECDSAPrivateKey.PublicKey, testECDSAPrivateKey)
+	if err != nil {
+		t.Fatalf("CreateCertificate: %v", err)
+	}
+
+	serverConfig := testConfig.Clone()
+	serverConfig.MaxVersion = version
+	serverConfig.Certificates = []Certificate{{
+		Certificate: [][]byte{certDER},
 		PrivateKey:  testECDSAPrivateKey,
 	}}
 	serverConfig.Time = func() time.Time {
-		return now.Add(1*time.Hour + 30*time.Minute)
+		return now
 	}
 	serverConfig.ClientCAs = x509.NewCertPool()
-	serverConfig.ClientCAs.AddCert(freshRoot)
+	serverConfig.ClientCAs.AddCert(rootA)
+	serverConfig.ClientAuth = RequireAndVerifyClientCert
+	serverConfig.InsecureSkipVerify = false
+	serverConfig.ServerName = "example.com"
+
+	clientConfig := testConfig.Clone()
+	clientConfig.MaxVersion = version
+	clientConfig.Certificates = []Certificate{{
+		Certificate: [][]byte{certDER},
+		PrivateKey:  testECDSAPrivateKey,
+	}}
+	clientConfig.ClientSessionCache = NewLRUClientSessionCache(32)
+	clientConfig.RootCAs = x509.NewCertPool()
+	clientConfig.RootCAs.AddCert(rootA)
+	clientConfig.Time = func() time.Time {
+		return now
+	}
+	clientConfig.InsecureSkipVerify = false
+	clientConfig.ServerName = "example.com"
+
+	testResume := func(t *testing.T, sc, cc *Config, expectResume bool) {
+		t.Helper()
+		ss, cs, err := testHandshake(t, cc, sc)
+		if err != nil {
+			t.Fatalf("handshake: %v", err)
+		}
+		if cs.DidResume != expectResume {
+			t.Fatalf("DidResume = %v; want %v", cs.DidResume, expectResume)
+		}
+		if ss.DidResume != expectResume {
+			t.Fatalf("DidResume = %v; want %v", cs.DidResume, expectResume)
+		}
+	}
 
 	testResume(t, serverConfig, clientConfig, false)
+	testResume(t, serverConfig, clientConfig, true)
+
+	clientConfig = clientConfig.Clone()
+	clientConfig.RootCAs = x509.NewCertPool()
+	clientConfig.RootCAs.AddCert(rootB)
+
+	testResume(t, serverConfig, clientConfig, false)
+	testResume(t, serverConfig, clientConfig, true)
 }

src/crypto/tls/handshake_server_tls13.go

@@ -14,6 +14,7 @@ import (
 	"crypto/internal/fips140/tls13"
 	"crypto/rsa"
 	"crypto/tls/internal/fips140tls"
+	"crypto/x509"
 	"errors"
 	"fmt"
 	"hash"
@@ -314,7 +315,6 @@ func (hs *serverHandshakeStateTLS13) checkForResumption() error {
 		return nil
 	}
 
-pskIdentityLoop:
 	for i, identity := range hs.clientHello.pskIdentities {
 		if i >= maxClientPSKIdentities {
 			break
@@ -367,16 +367,16 @@ pskIdentityLoop:
 		if sessionHasClientCerts && c.config.ClientAuth == NoClientCert {
 			continue
 		}
-		if sessionHasClientCerts {
-			now := c.config.time()
-			for _, c := range sessionState.peerCertificates {
-				if now.After(c.NotAfter) {
-					continue pskIdentityLoop
-				}
-			}
+		if sessionHasClientCerts && c.config.time().After(sessionState.peerCertificates[0].NotAfter) {
+			continue
+		}
+		opts := x509.VerifyOptions{
+			CurrentTime: c.config.time(),
+			Roots:       c.config.ClientCAs,
+			KeyUsages:   []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth},
 		}
 		if sessionHasClientCerts && c.config.ClientAuth >= VerifyClientCertIfGiven &&
-			len(sessionState.verifiedChains) == 0 {
+			!anyValidVerifiedChain(sessionState.verifiedChains, opts) {
 			continue
 		}
 

src/crypto/tls/tls_test.go

@@ -935,8 +935,8 @@ func TestCloneNonFuncFields(t *testing.T) {
 		}
 	}
 	// Set the unexported fields related to session ticket keys, which are copied with Clone().
+	c1.autoSessionTicketKeys = []ticketKey{c1.ticketKeyFromBytes(c1.SessionTicketKey)}
 	c1.sessionTicketKeys = []ticketKey{c1.ticketKeyFromBytes(c1.SessionTicketKey)}
-	// We explicitly don't copy autoSessionTicketKeys in Clone, so don't set it.
 
 	c2 := c1.Clone()
 	if !reflect.DeepEqual(&c1, c2) {
@@ -2461,12 +2461,3 @@ func (s messageOnlySigner) SignMessage(rand io.Reader, msg []byte, opts crypto.S
 	digest := h.Sum(nil)
 	return s.Signer.Sign(rand, digest, opts)
 }
-
-func TestConfigCloneAutoSessionTicketKeys(t *testing.T) {
-	orig := &Config{}
-	orig.ticketKeys(nil)
-	clone := orig.Clone()
-	if slices.Equal(orig.autoSessionTicketKeys, clone.autoSessionTicketKeys) {
-		t.Fatal("autoSessionTicketKeys slice copied in Clone")
-	}
-}

src/internal/buildcfg/exp.go

@@ -81,12 +81,11 @@ func ParseGOEXPERIMENT(goos, goarch, goexp string) (*ExperimentFlags, error) {
 	dwarf5Supported := (goos != "darwin" && goos != "ios" && goos != "aix")
 
 	baseline := goexperiment.Flags{
-		RegabiWrappers:        regabiSupported,
-		RegabiArgs:            regabiSupported,
-		Dwarf5:                dwarf5Supported,
-		RandomizedHeapBase64:  true,
-		SizeSpecializedMalloc: true,
-		GreenTeaGC:            true,
+		RegabiWrappers:       regabiSupported,
+		RegabiArgs:           regabiSupported,
+		Dwarf5:               dwarf5Supported,
+		RandomizedHeapBase64: true,
+		GreenTeaGC:           true,
 	}
 	flags := &ExperimentFlags{
 		Flags:    baseline,

src/internal/cpu/cpu.go

@@ -56,6 +56,7 @@ var X86 struct {
 	HasSSSE3            bool
 	HasSSE41            bool
 	HasSSE42            bool
+	HasVAES             bool
 	_                   CacheLinePad
 }
 

src/internal/cpu/cpu_x86.go

@@ -28,7 +28,7 @@ const (
 	cpuid_AVX512VBMI2     = 1 << 6
 	cpuid_SSSE3           = 1 << 9
 	cpuid_AVX512GFNI      = 1 << 8
-	cpuid_AVX512VAES      = 1 << 9
+	cpuid_VAES            = 1 << 9
 	cpuid_AVX512VNNI      = 1 << 11
 	cpuid_AVX512BITALG    = 1 << 12
 	cpuid_FMA             = 1 << 12
@@ -173,6 +173,7 @@ func doinit() {
 	X86.HasERMS = isSet(ebx7, cpuid_ERMS)
 	X86.HasADX = isSet(ebx7, cpuid_ADX)
 	X86.HasSHA = isSet(ebx7, cpuid_SHA)
+	X86.HasVAES = isSet(ecx7, cpuid_VAES) && X86.HasAVX
 
 	X86.HasAVX512F = isSet(ebx7, cpuid_AVX512F) && osSupportsAVX512
 	if X86.HasAVX512F {
@@ -185,7 +186,7 @@ func doinit() {
 		X86.HasAVX512VPOPCNTDQ = isSet(ecx7, cpuid_AVX512VPOPCNTDQ)
 		X86.HasAVX512VBMI = isSet(ecx7, cpuid_AVX512VBMI)
 		X86.HasAVX512VBMI2 = isSet(ecx7, cpuid_AVX512VBMI2)
-		X86.HasAVX512VAES = isSet(ecx7, cpuid_AVX512VAES)
+		X86.HasAVX512VAES = isSet(ecx7, cpuid_VAES) && X86.HasAES && isSet(ebx7, cpuid_AVX512VL)
 		X86.HasAVX512VNNI = isSet(ecx7, cpuid_AVX512VNNI)
 		X86.HasAVX512VPCLMULQDQ = isSet(ecx7, cpuid_AVX512VPCLMULQDQ)
 		X86.HasAVX512VBMI = isSet(ecx7, cpuid_AVX512_VBMI)

src/simd/archsimd/_gen/simdgen/xed.go

@@ -77,7 +77,8 @@ func loadXED(xedPath string) []*unify.Value {
 		switch {
 		case inst.RealOpcode == "N":
 			return // Skip unstable instructions
-		case !(strings.HasPrefix(inst.Extension, "AVX") || strings.HasPrefix(inst.Extension, "SHA") || inst.Extension == "FMA"):
+		case !(strings.HasPrefix(inst.Extension, "AVX") || strings.HasPrefix(inst.Extension, "SHA") ||
+			inst.Extension == "FMA" || inst.Extension == "VAES"):
 			// We're only interested in AVX and SHA instructions.
 			return
 		}
@@ -796,6 +797,7 @@ var cpuFeatureMap = map[string]string{
 	"AVXAES":   "AVXAES",
 	"SHA":      "SHA",
 	"FMA":      "FMA",
+	"VAES":     "VAES",
 
 	// AVX-512 foundational features. We combine all of these into one "AVX512" feature.
 	"AVX512F":  "AVX512",
@@ -829,6 +831,7 @@ func init() {
 
 		"AVXAES": {Virtual: true, Implies: []string{"AVX", "AES"}},
 		"FMA":    {Implies: []string{"AVX"}},
+		"VAES":   {Implies: []string{"AVX"}},
 
 		// AVX-512 subfeatures.
 		"AVX512BITALG":    {Implies: []string{"AVX512"}},

src/simd/archsimd/cpu.go

@@ -158,3 +158,13 @@ func (X86Features) FMA() bool {
 func (X86Features) SHA() bool {
 	return cpu.X86.HasSHA
 }
+
+// VAES returns whether the CPU supports the VAES feature.
+//
+// If it returns true, then the CPU also supports AVX.
+//
+// VAES is defined on all GOARCHes, but will only return true on
+// GOARCH amd64.
+func (X86Features) VAES() bool {
+	return cpu.X86.HasVAES
+}

src/simd/archsimd/ops_amd64.go

@@ -19,7 +19,7 @@ func (x Uint8x16) AESDecryptLastRound(y Uint32x4) Uint8x16
 // y is the chunk of dw array in use.
 // result = AddRoundKey(InvShiftRows(InvSubBytes(x)), y)
 //
-// Asm: VAESDECLAST, CPU Feature: AVX512VAES
+// Asm: VAESDECLAST, CPU Feature: VAES
 func (x Uint8x32) AESDecryptLastRound(y Uint32x8) Uint8x32
 
 // AESDecryptLastRound performs a series of operations in AES cipher algorithm defined in FIPS 197.
@@ -45,7 +45,7 @@ func (x Uint8x16) AESDecryptOneRound(y Uint32x4) Uint8x16
 // y is the chunk of dw array in use.
 // result = AddRoundKey(InvMixColumns(InvShiftRows(InvSubBytes(x))), y)
 //
-// Asm: VAESDEC, CPU Feature: AVX512VAES
+// Asm: VAESDEC, CPU Feature: VAES
 func (x Uint8x32) AESDecryptOneRound(y Uint32x8) Uint8x32
 
 // AESDecryptOneRound performs a series of operations in AES cipher algorithm defined in FIPS 197.
@@ -71,7 +71,7 @@ func (x Uint8x16) AESEncryptLastRound(y Uint32x4) Uint8x16
 // y is the chunk of w array in use.
 // result = AddRoundKey((ShiftRows(SubBytes(x))), y)
 //
-// Asm: VAESENCLAST, CPU Feature: AVX512VAES
+// Asm: VAESENCLAST, CPU Feature: VAES
 func (x Uint8x32) AESEncryptLastRound(y Uint32x8) Uint8x32
 
 // AESEncryptLastRound performs a series of operations in AES cipher algorithm defined in FIPS 197.
@@ -97,7 +97,7 @@ func (x Uint8x16) AESEncryptOneRound(y Uint32x4) Uint8x16
 // y is the chunk of w array in use.
 // result = AddRoundKey(MixColumns(ShiftRows(SubBytes(x))), y)
 //
-// Asm: VAESENC, CPU Feature: AVX512VAES
+// Asm: VAESENC, CPU Feature: VAES
 func (x Uint8x32) AESEncryptOneRound(y Uint32x8) Uint8x32
 
 // AESEncryptOneRound performs a series of operations in AES cipher algorithm defined in FIPS 197.