crypto/tls: align FIPS-only mode with BoringSSL policy

This enables TLS 1.3, disables P-521, and disables non-ECDHE suites.

Fixes #64717
Updates #62372

Change-Id: I3a65b239ef0198bbdbe5e55e0810e7128f90a091
Reviewed-on: https://go-review.googlesource.com/c/go/+/549975
Reviewed-by: Roland Shoemaker <roland@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Than McIntosh <thanm@google.com>
This commit is contained in:
Filippo Valsorda 2023-12-14 22:13:29 +01:00 committed by Roland Shoemaker
parent 7383b2a4db
commit 4106de901a
11 changed files with 125 additions and 57 deletions

View file

@ -228,26 +228,41 @@ func (c *aesCipher) NewGCM(nonceSize, tagSize int) (cipher.AEAD, error) {
if tagSize != gcmTagSize {
return cipher.NewGCMWithTagSize(&noGCM{c}, tagSize)
}
return c.newGCM(false)
return c.newGCM(0)
}
const (
VersionTLS12 = 0x0303
VersionTLS13 = 0x0304
)
func NewGCMTLS(c cipher.Block) (cipher.AEAD, error) {
return c.(*aesCipher).newGCM(true)
return c.(*aesCipher).newGCM(VersionTLS12)
}
func (c *aesCipher) newGCM(tls bool) (cipher.AEAD, error) {
func NewGCMTLS13(c cipher.Block) (cipher.AEAD, error) {
return c.(*aesCipher).newGCM(VersionTLS13)
}
func (c *aesCipher) newGCM(tlsVersion uint16) (cipher.AEAD, error) {
var aead *C.GO_EVP_AEAD
switch len(c.key) * 8 {
case 128:
if tls {
switch tlsVersion {
case VersionTLS12:
aead = C._goboringcrypto_EVP_aead_aes_128_gcm_tls12()
} else {
case VersionTLS13:
aead = C._goboringcrypto_EVP_aead_aes_128_gcm_tls13()
default:
aead = C._goboringcrypto_EVP_aead_aes_128_gcm()
}
case 256:
if tls {
switch tlsVersion {
case VersionTLS12:
aead = C._goboringcrypto_EVP_aead_aes_256_gcm_tls12()
} else {
case VersionTLS13:
aead = C._goboringcrypto_EVP_aead_aes_256_gcm_tls13()
default:
aead = C._goboringcrypto_EVP_aead_aes_256_gcm()
}
default:

View file

@ -50,6 +50,7 @@ func NewHMAC(h func() hash.Hash, key []byte) hash.Hash { panic("boringcrypto: no
func NewAESCipher(key []byte) (cipher.Block, error) { panic("boringcrypto: not available") }
func NewGCMTLS(cipher.Block) (cipher.AEAD, error) { panic("boringcrypto: not available") }
func NewGCMTLS13(cipher.Block) (cipher.AEAD, error) { panic("boringcrypto: not available") }
type PublicKeyECDSA struct{ _ int }
type PrivateKeyECDSA struct{ _ int }

View file

@ -6,9 +6,10 @@
package tls
import (
"crypto/internal/boring/fipstls"
)
import "crypto/internal/boring/fipstls"
// The FIPS-only policies enforced here currently match BoringSSL's
// ssl_policy_fips_202205.
// needFIPS returns fipstls.Required(); it avoids a new import in common.go.
func needFIPS() bool {
@ -17,19 +18,19 @@ func needFIPS() bool {
// fipsMinVersion replaces c.minVersion in FIPS-only mode.
func fipsMinVersion(c *Config) uint16 {
// FIPS requires TLS 1.2.
// FIPS requires TLS 1.2 or TLS 1.3.
return VersionTLS12
}
// fipsMaxVersion replaces c.maxVersion in FIPS-only mode.
func fipsMaxVersion(c *Config) uint16 {
// FIPS requires TLS 1.2.
return VersionTLS12
// FIPS requires TLS 1.2 or TLS 1.3.
return VersionTLS13
}
// default defaultFIPSCurvePreferences is the FIPS-allowed curves,
// in preference order (most preferable first).
var defaultFIPSCurvePreferences = []CurveID{CurveP256, CurveP384, CurveP521}
var defaultFIPSCurvePreferences = []CurveID{CurveP256, CurveP384}
// fipsCurvePreferences replaces c.curvePreferences in FIPS-only mode.
func fipsCurvePreferences(c *Config) []CurveID {
@ -54,8 +55,6 @@ var defaultCipherSuitesFIPS = []uint16{
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
TLS_RSA_WITH_AES_128_GCM_SHA256,
TLS_RSA_WITH_AES_256_GCM_SHA384,
}
// fipsCipherSuites replaces c.cipherSuites in FIPS-only mode.
@ -75,8 +74,14 @@ func fipsCipherSuites(c *Config) []uint16 {
return list
}
// defaultCipherSuitesTLS13FIPS are the FIPS-allowed cipher suites for TLS 1.3.
var defaultCipherSuitesTLS13FIPS = []uint16{
TLS_AES_128_GCM_SHA256,
TLS_AES_256_GCM_SHA384,
}
// fipsSupportedSignatureAlgorithms currently are a subset of
// defaultSupportedSignatureAlgorithms without Ed25519 and SHA-1.
// defaultSupportedSignatureAlgorithms without Ed25519, SHA-1, and P-521.
var fipsSupportedSignatureAlgorithms = []SignatureScheme{
PSSWithSHA256,
PSSWithSHA384,
@ -86,7 +91,6 @@ var fipsSupportedSignatureAlgorithms = []SignatureScheme{
PKCS1WithSHA384,
ECDSAWithP384AndSHA384,
PKCS1WithSHA512,
ECDSAWithP521AndSHA512,
}
// supportedSignatureAlgorithms returns the supported signature algorithms.

View file

@ -25,6 +25,31 @@ import (
"time"
)
func allCipherSuitesIncludingTLS13() []uint16 {
s := allCipherSuites()
for _, suite := range cipherSuitesTLS13 {
s = append(s, suite.id)
}
return s
}
func isTLS13CipherSuite(id uint16) bool {
for _, suite := range cipherSuitesTLS13 {
if id == suite.id {
return true
}
}
return false
}
func generateKeyShare(group CurveID) keyShare {
key, err := generateECDHEKey(rand.Reader, group)
if err != nil {
panic(err)
}
return keyShare{group: group, data: key.PublicKey().Bytes()}
}
func TestBoringServerProtocolVersion(t *testing.T) {
test := func(name string, v uint16, msg string) {
t.Run(name, func(t *testing.T) {
@ -33,8 +58,11 @@ func TestBoringServerProtocolVersion(t *testing.T) {
clientHello := &clientHelloMsg{
vers: v,
random: make([]byte, 32),
cipherSuites: allCipherSuites(),
cipherSuites: allCipherSuitesIncludingTLS13(),
compressionMethods: []uint8{compressionNone},
supportedCurves: defaultCurvePreferences,
keyShares: []keyShare{generateKeyShare(CurveP256)},
supportedPoints: []uint8{pointFormatUncompressed},
supportedVersions: []uint16{v},
}
testClientHelloFailure(t, serverConfig, clientHello, msg)
@ -48,25 +76,25 @@ func TestBoringServerProtocolVersion(t *testing.T) {
fipstls.Force()
defer fipstls.Abandon()
test("VersionSSL30", VersionSSL30, "client offered only unsupported versions")
test("VersionTLS10", VersionTLS10, "client offered only unsupported versions")
test("VersionTLS11", VersionTLS11, "client offered only unsupported versions")
test("VersionTLS12", VersionTLS12, "")
test("VersionTLS13", VersionTLS13, "client offered only unsupported versions")
test("VersionSSL30/fipstls", VersionSSL30, "client offered only unsupported versions")
test("VersionTLS10/fipstls", VersionTLS10, "client offered only unsupported versions")
test("VersionTLS11/fipstls", VersionTLS11, "client offered only unsupported versions")
test("VersionTLS12/fipstls", VersionTLS12, "")
test("VersionTLS13/fipstls", VersionTLS13, "")
}
func isBoringVersion(v uint16) bool {
return v == VersionTLS12
return v == VersionTLS12 || v == VersionTLS13
}
func isBoringCipherSuite(id uint16) bool {
switch id {
case TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
case TLS_AES_128_GCM_SHA256,
TLS_AES_256_GCM_SHA384,
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
TLS_RSA_WITH_AES_128_GCM_SHA256,
TLS_RSA_WITH_AES_256_GCM_SHA384:
TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384:
return true
}
return false
@ -74,7 +102,7 @@ func isBoringCipherSuite(id uint16) bool {
func isBoringCurve(id CurveID) bool {
switch id {
case CurveP256, CurveP384, CurveP521:
case CurveP256, CurveP384:
return true
}
return false
@ -86,7 +114,7 @@ func isECDSA(id uint16) bool {
return suite.flags&suiteECSign == suiteECSign
}
}
panic(fmt.Sprintf("unknown cipher suite %#x", id))
return false // TLS 1.3 cipher suites are not tied to the signature algorithm.
}
func isBoringSignatureScheme(alg SignatureScheme) bool {
@ -98,7 +126,6 @@ func isBoringSignatureScheme(alg SignatureScheme) bool {
PKCS1WithSHA384,
ECDSAWithP384AndSHA384,
PKCS1WithSHA512,
ECDSAWithP521AndSHA512,
PSSWithSHA256,
PSSWithSHA384,
PSSWithSHA512:
@ -109,10 +136,9 @@ func isBoringSignatureScheme(alg SignatureScheme) bool {
func TestBoringServerCipherSuites(t *testing.T) {
serverConfig := testConfig.Clone()
serverConfig.CipherSuites = allCipherSuites()
serverConfig.Certificates = make([]Certificate, 1)
for _, id := range allCipherSuites() {
for _, id := range allCipherSuitesIncludingTLS13() {
if isECDSA(id) {
serverConfig.Certificates[0].Certificate = [][]byte{testECDSACertificate}
serverConfig.Certificates[0].PrivateKey = testECDSAPrivateKey
@ -121,14 +147,19 @@ func TestBoringServerCipherSuites(t *testing.T) {
serverConfig.Certificates[0].PrivateKey = testRSAPrivateKey
}
serverConfig.BuildNameToCertificate()
t.Run(fmt.Sprintf("suite=%#x", id), func(t *testing.T) {
t.Run(fmt.Sprintf("suite=%s", CipherSuiteName(id)), func(t *testing.T) {
clientHello := &clientHelloMsg{
vers: VersionTLS12,
random: make([]byte, 32),
cipherSuites: []uint16{id},
compressionMethods: []uint8{compressionNone},
supportedCurves: defaultCurvePreferences,
keyShares: []keyShare{generateKeyShare(CurveP256)},
supportedPoints: []uint8{pointFormatUncompressed},
supportedVersions: []uint16{VersionTLS12},
}
if isTLS13CipherSuite(id) {
clientHello.supportedVersions = []uint16{VersionTLS13}
}
testClientHello(t, serverConfig, clientHello)
@ -160,7 +191,9 @@ func TestBoringServerCurves(t *testing.T) {
cipherSuites: []uint16{TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256},
compressionMethods: []uint8{compressionNone},
supportedCurves: []CurveID{curveid},
keyShares: []keyShare{generateKeyShare(curveid)},
supportedPoints: []uint8{pointFormatUncompressed},
supportedVersions: []uint16{VersionTLS12},
}
testClientHello(t, serverConfig, clientHello)
@ -279,7 +312,7 @@ func TestBoringClientHello(t *testing.T) {
}
if !isBoringVersion(hello.vers) {
t.Errorf("client vers=%#x, want %#x (TLS 1.2)", hello.vers, VersionTLS12)
t.Errorf("client vers=%#x", hello.vers)
}
for _, v := range hello.supportedVersions {
if !isBoringVersion(v) {

View file

@ -556,7 +556,13 @@ func aeadAESGCMTLS13(key, nonceMask []byte) aead {
if err != nil {
panic(err)
}
aead, err := cipher.NewGCM(aes)
var aead cipher.AEAD
if boring.Enabled {
aead, err = boring.NewGCMTLS13(aes)
} else {
boring.Unreachable()
aead, err = cipher.NewGCM(aes)
}
if err != nil {
panic(err)
}

View file

@ -139,7 +139,9 @@ func (c *Conn) makeClientHello() (*clientHelloMsg, *ecdh.PrivateKey, error) {
if len(hello.supportedVersions) == 1 {
hello.cipherSuites = nil
}
if hasAESGCMHardwareSupport {
if needFIPS() {
hello.cipherSuites = append(hello.cipherSuites, defaultCipherSuitesTLS13FIPS...)
} else if hasAESGCMHardwareSupport {
hello.cipherSuites = append(hello.cipherSuites, defaultCipherSuitesTLS13...)
} else {
hello.cipherSuites = append(hello.cipherSuites, defaultCipherSuitesTLS13NoAES...)

View file

@ -41,10 +41,6 @@ type clientHandshakeStateTLS13 struct {
func (hs *clientHandshakeStateTLS13) handshake() error {
c := hs.c
if needFIPS() {
return errors.New("tls: internal error: TLS 1.3 reached in FIPS mode")
}
// The server must not select TLS 1.3 in a renegotiation. See RFC 8446,
// sections 4.1.2 and 4.1.3.
if c.handshakes > 0 {

View file

@ -27,6 +27,7 @@ import (
)
func testClientHello(t *testing.T, serverConfig *Config, m handshakeMessage) {
t.Helper()
testClientHelloFailure(t, serverConfig, m, "")
}
@ -52,23 +53,32 @@ func testClientHelloFailure(t *testing.T, serverConfig *Config, m handshakeMessa
ctx := context.Background()
conn := Server(s, serverConfig)
ch, err := conn.readClientHello(ctx)
hs := serverHandshakeState{
c: conn,
ctx: ctx,
clientHello: ch,
}
if err == nil {
if err == nil && conn.vers == VersionTLS13 {
hs := serverHandshakeStateTLS13{
c: conn,
ctx: ctx,
clientHello: ch,
}
err = hs.processClientHello()
}
if err == nil {
err = hs.pickCipherSuite()
} else if err == nil {
hs := serverHandshakeState{
c: conn,
ctx: ctx,
clientHello: ch,
}
err = hs.processClientHello()
if err == nil {
err = hs.pickCipherSuite()
}
}
s.Close()
if len(expectedSubStr) == 0 {
if err != nil && err != io.EOF {
t.Helper()
t.Errorf("Got error: %s; expected to succeed", err)
}
} else if err == nil || !strings.Contains(err.Error(), expectedSubStr) {
t.Helper()
t.Errorf("Got error: %v; expected to match substring '%s'", err, expectedSubStr)
}
}

View file

@ -45,10 +45,6 @@ type serverHandshakeStateTLS13 struct {
func (hs *serverHandshakeStateTLS13) handshake() error {
c := hs.c
if needFIPS() {
return errors.New("tls: internal error: TLS 1.3 reached in FIPS mode")
}
// For an overview of the TLS 1.3 handshake, see RFC 8446, Section 2.
if err := hs.processClientHello(); err != nil {
return err
@ -163,6 +159,9 @@ func (hs *serverHandshakeStateTLS13) processClientHello() error {
if !hasAESGCMHardwareSupport || !aesgcmPreferred(hs.clientHello.cipherSuites) {
preferenceList = defaultCipherSuitesTLS13NoAES
}
if needFIPS() {
preferenceList = defaultCipherSuitesTLS13FIPS
}
for _, suiteID := range preferenceList {
hs.suite = mutualCipherSuiteTLS13(hs.clientHello.cipherSuites, suiteID)
if hs.suite != nil {

View file

@ -18,3 +18,5 @@ func fipsCurvePreferences(c *Config) []CurveID { panic("fipsCurvePreferences") }
func fipsCipherSuites(c *Config) []uint16 { panic("fipsCipherSuites") }
var fipsSupportedSignatureAlgorithms []SignatureScheme
var defaultCipherSuitesTLS13FIPS []uint16

View file

@ -22,7 +22,7 @@ func boringAllowCert(c *Certificate) bool {
}
// The key must be RSA 2048, RSA 3072, RSA 4096,
// or ECDSA P-256, P-384, P-521.
// or ECDSA P-256 or P-384.
switch k := c.PublicKey.(type) {
default:
return false
@ -31,7 +31,7 @@ func boringAllowCert(c *Certificate) bool {
return false
}
case *ecdsa.PublicKey:
if k.Curve != elliptic.P256() && k.Curve != elliptic.P384() && k.Curve != elliptic.P521() {
if k.Curve != elliptic.P256() && k.Curve != elliptic.P384() {
return false
}
}