Adding upstream version 1.21.8.upstream/1.21.8

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 694 insertions, 0 deletions

diff --git a/src/crypto/tls/cipher_suites.go b/src/crypto/tls/cipher_suites.go
new file mode 100644
index 0000000..589e8b6
--- /dev/null
+++ b/src/crypto/tls/cipher_suites.go
@@ -0,0 +1,694 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package tls
+
+import (
+	"crypto"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/des"
+	"crypto/hmac"
+	"crypto/internal/boring"
+	"crypto/rc4"
+	"crypto/sha1"
+	"crypto/sha256"
+	"fmt"
+	"hash"
+	"internal/cpu"
+	"runtime"
+
+	"golang.org/x/crypto/chacha20poly1305"
+)
+
+// CipherSuite is a TLS cipher suite. Note that most functions in this package
+// accept and expose cipher suite IDs instead of this type.
+type CipherSuite struct {
+	ID   uint16
+	Name string
+
+	// Supported versions is the list of TLS protocol versions that can
+	// negotiate this cipher suite.
+	SupportedVersions []uint16
+
+	// Insecure is true if the cipher suite has known security issues
+	// due to its primitives, design, or implementation.
+	Insecure bool
+}
+
+var (
+	supportedUpToTLS12 = []uint16{VersionTLS10, VersionTLS11, VersionTLS12}
+	supportedOnlyTLS12 = []uint16{VersionTLS12}
+	supportedOnlyTLS13 = []uint16{VersionTLS13}
+)
+
+// CipherSuites returns a list of cipher suites currently implemented by this
+// package, excluding those with security issues, which are returned by
+// InsecureCipherSuites.
+//
+// The list is sorted by ID. Note that the default cipher suites selected by
+// this package might depend on logic that can't be captured by a static list,
+// and might not match those returned by this function.
+func CipherSuites() []*CipherSuite {
+	return []*CipherSuite{
+		{TLS_RSA_WITH_AES_128_CBC_SHA, "TLS_RSA_WITH_AES_128_CBC_SHA", supportedUpToTLS12, false},
+		{TLS_RSA_WITH_AES_256_CBC_SHA, "TLS_RSA_WITH_AES_256_CBC_SHA", supportedUpToTLS12, false},
+		{TLS_RSA_WITH_AES_128_GCM_SHA256, "TLS_RSA_WITH_AES_128_GCM_SHA256", supportedOnlyTLS12, false},
+		{TLS_RSA_WITH_AES_256_GCM_SHA384, "TLS_RSA_WITH_AES_256_GCM_SHA384", supportedOnlyTLS12, false},
+
+		{TLS_AES_128_GCM_SHA256, "TLS_AES_128_GCM_SHA256", supportedOnlyTLS13, false},
+		{TLS_AES_256_GCM_SHA384, "TLS_AES_256_GCM_SHA384", supportedOnlyTLS13, false},
+		{TLS_CHACHA20_POLY1305_SHA256, "TLS_CHACHA20_POLY1305_SHA256", supportedOnlyTLS13, false},
+
+		{TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA", supportedUpToTLS12, false},
+		{TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, "TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA", supportedUpToTLS12, false},
+		{TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA", supportedUpToTLS12, false},
+		{TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA, "TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA", supportedUpToTLS12, false},
+		{TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256", supportedOnlyTLS12, false},
+		{TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, "TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384", supportedOnlyTLS12, false},
+		{TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256", supportedOnlyTLS12, false},
+		{TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, "TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384", supportedOnlyTLS12, false},
+		{TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256, "TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256", supportedOnlyTLS12, false},
+		{TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256, "TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256", supportedOnlyTLS12, false},
+	}
+}
+
+// InsecureCipherSuites returns a list of cipher suites currently implemented by
+// this package and which have security issues.
+//
+// Most applications should not use the cipher suites in this list, and should
+// only use those returned by CipherSuites.
+func InsecureCipherSuites() []*CipherSuite {
+	// This list includes RC4, CBC_SHA256, and 3DES cipher suites. See
+	// cipherSuitesPreferenceOrder for details.
+	return []*CipherSuite{
+		{TLS_RSA_WITH_RC4_128_SHA, "TLS_RSA_WITH_RC4_128_SHA", supportedUpToTLS12, true},
+		{TLS_RSA_WITH_3DES_EDE_CBC_SHA, "TLS_RSA_WITH_3DES_EDE_CBC_SHA", supportedUpToTLS12, true},
+		{TLS_RSA_WITH_AES_128_CBC_SHA256, "TLS_RSA_WITH_AES_128_CBC_SHA256", supportedOnlyTLS12, true},
+		{TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, "TLS_ECDHE_ECDSA_WITH_RC4_128_SHA", supportedUpToTLS12, true},
+		{TLS_ECDHE_RSA_WITH_RC4_128_SHA, "TLS_ECDHE_RSA_WITH_RC4_128_SHA", supportedUpToTLS12, true},
+		{TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, "TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA", supportedUpToTLS12, true},
+		{TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256", supportedOnlyTLS12, true},
+		{TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256", supportedOnlyTLS12, true},
+	}
+}
+
+// CipherSuiteName returns the standard name for the passed cipher suite ID
+// (e.g. "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256"), or a fallback representation
+// of the ID value if the cipher suite is not implemented by this package.
+func CipherSuiteName(id uint16) string {
+	for _, c := range CipherSuites() {
+		if c.ID == id {
+			return c.Name
+		}
+	}
+	for _, c := range InsecureCipherSuites() {
+		if c.ID == id {
+			return c.Name
+		}
+	}
+	return fmt.Sprintf("0x%04X", id)
+}
+
+const (
+	// suiteECDHE indicates that the cipher suite involves elliptic curve
+	// Diffie-Hellman. This means that it should only be selected when the
+	// client indicates that it supports ECC with a curve and point format
+	// that we're happy with.
+	suiteECDHE = 1 << iota
+	// suiteECSign indicates that the cipher suite involves an ECDSA or
+	// EdDSA signature and therefore may only be selected when the server's
+	// certificate is ECDSA or EdDSA. If this is not set then the cipher suite
+	// is RSA based.
+	suiteECSign
+	// suiteTLS12 indicates that the cipher suite should only be advertised
+	// and accepted when using TLS 1.2.
+	suiteTLS12
+	// suiteSHA384 indicates that the cipher suite uses SHA384 as the
+	// handshake hash.
+	suiteSHA384
+)
+
+// A cipherSuite is a TLS 1.0–1.2 cipher suite, and defines the key exchange
+// mechanism, as well as the cipher+MAC pair or the AEAD.
+type cipherSuite struct {
+	id uint16
+	// the lengths, in bytes, of the key material needed for each component.
+	keyLen int
+	macLen int
+	ivLen  int
+	ka     func(version uint16) keyAgreement
+	// flags is a bitmask of the suite* values, above.
+	flags  int
+	cipher func(key, iv []byte, isRead bool) any
+	mac    func(key []byte) hash.Hash
+	aead   func(key, fixedNonce []byte) aead
+}
+
+var cipherSuites = []*cipherSuite{ // TODO: replace with a map, since the order doesn't matter.
+	{TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305, 32, 0, 12, ecdheRSAKA, suiteECDHE | suiteTLS12, nil, nil, aeadChaCha20Poly1305},
+	{TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305, 32, 0, 12, ecdheECDSAKA, suiteECDHE | suiteECSign | suiteTLS12, nil, nil, aeadChaCha20Poly1305},
+	{TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, 16, 0, 4, ecdheRSAKA, suiteECDHE | suiteTLS12, nil, nil, aeadAESGCM},
+	{TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, 16, 0, 4, ecdheECDSAKA, suiteECDHE | suiteECSign | suiteTLS12, nil, nil, aeadAESGCM},
+	{TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, 32, 0, 4, ecdheRSAKA, suiteECDHE | suiteTLS12 | suiteSHA384, nil, nil, aeadAESGCM},
+	{TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, 32, 0, 4, ecdheECDSAKA, suiteECDHE | suiteECSign | suiteTLS12 | suiteSHA384, nil, nil, aeadAESGCM},
+	{TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, 16, 32, 16, ecdheRSAKA, suiteECDHE | suiteTLS12, cipherAES, macSHA256, nil},
+	{TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, 16, 20, 16, ecdheRSAKA, suiteECDHE, cipherAES, macSHA1, nil},
+	{TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, 16, 32, 16, ecdheECDSAKA, suiteECDHE | suiteECSign | suiteTLS12, cipherAES, macSHA256, nil},
+	{TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, 16, 20, 16, ecdheECDSAKA, suiteECDHE | suiteECSign, cipherAES, macSHA1, nil},
+	{TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA, 32, 20, 16, ecdheRSAKA, suiteECDHE, cipherAES, macSHA1, nil},
+	{TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, 32, 20, 16, ecdheECDSAKA, suiteECDHE | suiteECSign, cipherAES, macSHA1, nil},
+	{TLS_RSA_WITH_AES_128_GCM_SHA256, 16, 0, 4, rsaKA, suiteTLS12, nil, nil, aeadAESGCM},
+	{TLS_RSA_WITH_AES_256_GCM_SHA384, 32, 0, 4, rsaKA, suiteTLS12 | suiteSHA384, nil, nil, aeadAESGCM},
+	{TLS_RSA_WITH_AES_128_CBC_SHA256, 16, 32, 16, rsaKA, suiteTLS12, cipherAES, macSHA256, nil},
+	{TLS_RSA_WITH_AES_128_CBC_SHA, 16, 20, 16, rsaKA, 0, cipherAES, macSHA1, nil},
+	{TLS_RSA_WITH_AES_256_CBC_SHA, 32, 20, 16, rsaKA, 0, cipherAES, macSHA1, nil},
+	{TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, 24, 20, 8, ecdheRSAKA, suiteECDHE, cipher3DES, macSHA1, nil},
+	{TLS_RSA_WITH_3DES_EDE_CBC_SHA, 24, 20, 8, rsaKA, 0, cipher3DES, macSHA1, nil},
+	{TLS_RSA_WITH_RC4_128_SHA, 16, 20, 0, rsaKA, 0, cipherRC4, macSHA1, nil},
+	{TLS_ECDHE_RSA_WITH_RC4_128_SHA, 16, 20, 0, ecdheRSAKA, suiteECDHE, cipherRC4, macSHA1, nil},
+	{TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, 16, 20, 0, ecdheECDSAKA, suiteECDHE | suiteECSign, cipherRC4, macSHA1, nil},
+}
+
+// selectCipherSuite returns the first TLS 1.0–1.2 cipher suite from ids which
+// is also in supportedIDs and passes the ok filter.
+func selectCipherSuite(ids, supportedIDs []uint16, ok func(*cipherSuite) bool) *cipherSuite {
+	for _, id := range ids {
+		candidate := cipherSuiteByID(id)
+		if candidate == nil || !ok(candidate) {
+			continue
+		}
+
+		for _, suppID := range supportedIDs {
+			if id == suppID {
+				return candidate
+			}
+		}
+	}
+	return nil
+}
+
+// A cipherSuiteTLS13 defines only the pair of the AEAD algorithm and hash
+// algorithm to be used with HKDF. See RFC 8446, Appendix B.4.
+type cipherSuiteTLS13 struct {
+	id     uint16
+	keyLen int
+	aead   func(key, fixedNonce []byte) aead
+	hash   crypto.Hash
+}
+
+var cipherSuitesTLS13 = []*cipherSuiteTLS13{ // TODO: replace with a map.
+	{TLS_AES_128_GCM_SHA256, 16, aeadAESGCMTLS13, crypto.SHA256},
+	{TLS_CHACHA20_POLY1305_SHA256, 32, aeadChaCha20Poly1305, crypto.SHA256},
+	{TLS_AES_256_GCM_SHA384, 32, aeadAESGCMTLS13, crypto.SHA384},
+}
+
+// cipherSuitesPreferenceOrder is the order in which we'll select (on the
+// server) or advertise (on the client) TLS 1.0–1.2 cipher suites.
+//
+// Cipher suites are filtered but not reordered based on the application and
+// peer's preferences, meaning we'll never select a suite lower in this list if
+// any higher one is available. This makes it more defensible to keep weaker
+// cipher suites enabled, especially on the server side where we get the last
+// word, since there are no known downgrade attacks on cipher suites selection.
+//
+// The list is sorted by applying the following priority rules, stopping at the
+// first (most important) applicable one:
+//
+//   - Anything else comes before RC4
+//
+//     RC4 has practically exploitable biases. See https://www.rc4nomore.com.
+//
+//   - Anything else comes before CBC_SHA256
+//
+//     SHA-256 variants of the CBC ciphersuites don't implement any Lucky13
+//     countermeasures. See http://www.isg.rhul.ac.uk/tls/Lucky13.html and
+//     https://www.imperialviolet.org/2013/02/04/luckythirteen.html.
+//
+//   - Anything else comes before 3DES
+//
+//     3DES has 64-bit blocks, which makes it fundamentally susceptible to
+//     birthday attacks. See https://sweet32.info.
+//
+//   - ECDHE comes before anything else
+//
+//     Once we got the broken stuff out of the way, the most important
+//     property a cipher suite can have is forward secrecy. We don't
+//     implement FFDHE, so that means ECDHE.
+//
+//   - AEADs come before CBC ciphers
+//
+//     Even with Lucky13 countermeasures, MAC-then-Encrypt CBC cipher suites
+//     are fundamentally fragile, and suffered from an endless sequence of
+//     padding oracle attacks. See https://eprint.iacr.org/2015/1129,
+//     https://www.imperialviolet.org/2014/12/08/poodleagain.html, and
+//     https://blog.cloudflare.com/yet-another-padding-oracle-in-openssl-cbc-ciphersuites/.
+//
+//   - AES comes before ChaCha20
+//
+//     When AES hardware is available, AES-128-GCM and AES-256-GCM are faster
+//     than ChaCha20Poly1305.
+//
+//     When AES hardware is not available, AES-128-GCM is one or more of: much
+//     slower, way more complex, and less safe (because not constant time)
+//     than ChaCha20Poly1305.
+//
+//     We use this list if we think both peers have AES hardware, and
+//     cipherSuitesPreferenceOrderNoAES otherwise.
+//
+//   - AES-128 comes before AES-256
+//
+//     The only potential advantages of AES-256 are better multi-target
+//     margins, and hypothetical post-quantum properties. Neither apply to
+//     TLS, and AES-256 is slower due to its four extra rounds (which don't
+//     contribute to the advantages above).
+//
+//   - ECDSA comes before RSA
+//
+//     The relative order of ECDSA and RSA cipher suites doesn't matter,
+//     as they depend on the certificate. Pick one to get a stable order.
+var cipherSuitesPreferenceOrder = []uint16{
+	// AEADs w/ ECDHE
+	TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
+	TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
+	TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305, TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,
+
+	// CBC w/ ECDHE
+	TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
+	TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
+
+	// AEADs w/o ECDHE
+	TLS_RSA_WITH_AES_128_GCM_SHA256,
+	TLS_RSA_WITH_AES_256_GCM_SHA384,
+
+	// CBC w/o ECDHE
+	TLS_RSA_WITH_AES_128_CBC_SHA,
+	TLS_RSA_WITH_AES_256_CBC_SHA,
+
+	// 3DES
+	TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
+	TLS_RSA_WITH_3DES_EDE_CBC_SHA,
+
+	// CBC_SHA256
+	TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,
+	TLS_RSA_WITH_AES_128_CBC_SHA256,
+
+	// RC4
+	TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, TLS_ECDHE_RSA_WITH_RC4_128_SHA,
+	TLS_RSA_WITH_RC4_128_SHA,
+}
+
+var cipherSuitesPreferenceOrderNoAES = []uint16{
+	// ChaCha20Poly1305
+	TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305, TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,
+
+	// AES-GCM w/ ECDHE
+	TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
+	TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
+
+	// The rest of cipherSuitesPreferenceOrder.
+	TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
+	TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
+	TLS_RSA_WITH_AES_128_GCM_SHA256,
+	TLS_RSA_WITH_AES_256_GCM_SHA384,
+	TLS_RSA_WITH_AES_128_CBC_SHA,
+	TLS_RSA_WITH_AES_256_CBC_SHA,
+	TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
+	TLS_RSA_WITH_3DES_EDE_CBC_SHA,
+	TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,
+	TLS_RSA_WITH_AES_128_CBC_SHA256,
+	TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, TLS_ECDHE_RSA_WITH_RC4_128_SHA,
+	TLS_RSA_WITH_RC4_128_SHA,
+}
+
+// disabledCipherSuites are not used unless explicitly listed in
+// Config.CipherSuites. They MUST be at the end of cipherSuitesPreferenceOrder.
+var disabledCipherSuites = []uint16{
+	// CBC_SHA256
+	TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,
+	TLS_RSA_WITH_AES_128_CBC_SHA256,
+
+	// RC4
+	TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, TLS_ECDHE_RSA_WITH_RC4_128_SHA,
+	TLS_RSA_WITH_RC4_128_SHA,
+}
+
+var (
+	defaultCipherSuitesLen = len(cipherSuitesPreferenceOrder) - len(disabledCipherSuites)
+	defaultCipherSuites    = cipherSuitesPreferenceOrder[:defaultCipherSuitesLen]
+)
+
+// defaultCipherSuitesTLS13 is also the preference order, since there are no
+// disabled by default TLS 1.3 cipher suites. The same AES vs ChaCha20 logic as
+// cipherSuitesPreferenceOrder applies.
+var defaultCipherSuitesTLS13 = []uint16{
+	TLS_AES_128_GCM_SHA256,
+	TLS_AES_256_GCM_SHA384,
+	TLS_CHACHA20_POLY1305_SHA256,
+}
+
+var defaultCipherSuitesTLS13NoAES = []uint16{
+	TLS_CHACHA20_POLY1305_SHA256,
+	TLS_AES_128_GCM_SHA256,
+	TLS_AES_256_GCM_SHA384,
+}
+
+var (
+	hasGCMAsmAMD64 = cpu.X86.HasAES && cpu.X86.HasPCLMULQDQ
+	hasGCMAsmARM64 = cpu.ARM64.HasAES && cpu.ARM64.HasPMULL
+	// Keep in sync with crypto/aes/cipher_s390x.go.
+	hasGCMAsmS390X = cpu.S390X.HasAES && cpu.S390X.HasAESCBC && cpu.S390X.HasAESCTR &&
+		(cpu.S390X.HasGHASH || cpu.S390X.HasAESGCM)
+
+	hasAESGCMHardwareSupport = runtime.GOARCH == "amd64" && hasGCMAsmAMD64 ||
+		runtime.GOARCH == "arm64" && hasGCMAsmARM64 ||
+		runtime.GOARCH == "s390x" && hasGCMAsmS390X
+)
+
+var aesgcmCiphers = map[uint16]bool{
+	// TLS 1.2
+	TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256:   true,
+	TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384:   true,
+	TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256: true,
+	TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384: true,
+	// TLS 1.3
+	TLS_AES_128_GCM_SHA256: true,
+	TLS_AES_256_GCM_SHA384: true,
+}
+
+// aesgcmPreferred returns whether the first known cipher in the preference list
+// is an AES-GCM cipher, implying the peer has hardware support for it.
+func aesgcmPreferred(ciphers []uint16) bool {
+	for _, cID := range ciphers {
+		if c := cipherSuiteByID(cID); c != nil {
+			return aesgcmCiphers[cID]
+		}
+		if c := cipherSuiteTLS13ByID(cID); c != nil {
+			return aesgcmCiphers[cID]
+		}
+	}
+	return false
+}
+
+func cipherRC4(key, iv []byte, isRead bool) any {
+	cipher, _ := rc4.NewCipher(key)
+	return cipher
+}
+
+func cipher3DES(key, iv []byte, isRead bool) any {
+	block, _ := des.NewTripleDESCipher(key)
+	if isRead {
+		return cipher.NewCBCDecrypter(block, iv)
+	}
+	return cipher.NewCBCEncrypter(block, iv)
+}
+
+func cipherAES(key, iv []byte, isRead bool) any {
+	block, _ := aes.NewCipher(key)
+	if isRead {
+		return cipher.NewCBCDecrypter(block, iv)
+	}
+	return cipher.NewCBCEncrypter(block, iv)
+}
+
+// macSHA1 returns a SHA-1 based constant time MAC.
+func macSHA1(key []byte) hash.Hash {
+	h := sha1.New
+	// The BoringCrypto SHA1 does not have a constant-time
+	// checksum function, so don't try to use it.
+	if !boring.Enabled {
+		h = newConstantTimeHash(h)
+	}
+	return hmac.New(h, key)
+}
+
+// macSHA256 returns a SHA-256 based MAC. This is only supported in TLS 1.2 and
+// is currently only used in disabled-by-default cipher suites.
+func macSHA256(key []byte) hash.Hash {
+	return hmac.New(sha256.New, key)
+}
+
+type aead interface {
+	cipher.AEAD
+
+	// explicitNonceLen returns the number of bytes of explicit nonce
+	// included in each record. This is eight for older AEADs and
+	// zero for modern ones.
+	explicitNonceLen() int
+}
+
+const (
+	aeadNonceLength   = 12
+	noncePrefixLength = 4
+)
+
+// prefixNonceAEAD wraps an AEAD and prefixes a fixed portion of the nonce to
+// each call.
+type prefixNonceAEAD struct {
+	// nonce contains the fixed part of the nonce in the first four bytes.
+	nonce [aeadNonceLength]byte
+	aead  cipher.AEAD
+}
+
+func (f *prefixNonceAEAD) NonceSize() int        { return aeadNonceLength - noncePrefixLength }
+func (f *prefixNonceAEAD) Overhead() int         { return f.aead.Overhead() }
+func (f *prefixNonceAEAD) explicitNonceLen() int { return f.NonceSize() }
+
+func (f *prefixNonceAEAD) Seal(out, nonce, plaintext, additionalData []byte) []byte {
+	copy(f.nonce[4:], nonce)
+	return f.aead.Seal(out, f.nonce[:], plaintext, additionalData)
+}
+
+func (f *prefixNonceAEAD) Open(out, nonce, ciphertext, additionalData []byte) ([]byte, error) {
+	copy(f.nonce[4:], nonce)
+	return f.aead.Open(out, f.nonce[:], ciphertext, additionalData)
+}
+
+// xorNonceAEAD wraps an AEAD by XORing in a fixed pattern to the nonce
+// before each call.
+type xorNonceAEAD struct {
+	nonceMask [aeadNonceLength]byte
+	aead      cipher.AEAD
+}
+
+func (f *xorNonceAEAD) NonceSize() int        { return 8 } // 64-bit sequence number
+func (f *xorNonceAEAD) Overhead() int         { return f.aead.Overhead() }
+func (f *xorNonceAEAD) explicitNonceLen() int { return 0 }
+
+func (f *xorNonceAEAD) Seal(out, nonce, plaintext, additionalData []byte) []byte {
+	for i, b := range nonce {
+		f.nonceMask[4+i] ^= b
+	}
+	result := f.aead.Seal(out, f.nonceMask[:], plaintext, additionalData)
+	for i, b := range nonce {
+		f.nonceMask[4+i] ^= b
+	}
+
+	return result
+}
+
+func (f *xorNonceAEAD) Open(out, nonce, ciphertext, additionalData []byte) ([]byte, error) {
+	for i, b := range nonce {
+		f.nonceMask[4+i] ^= b
+	}
+	result, err := f.aead.Open(out, f.nonceMask[:], ciphertext, additionalData)
+	for i, b := range nonce {
+		f.nonceMask[4+i] ^= b
+	}
+
+	return result, err
+}
+
+func aeadAESGCM(key, noncePrefix []byte) aead {
+	if len(noncePrefix) != noncePrefixLength {
+		panic("tls: internal error: wrong nonce length")
+	}
+	aes, err := aes.NewCipher(key)
+	if err != nil {
+		panic(err)
+	}
+	var aead cipher.AEAD
+	if boring.Enabled {
+		aead, err = boring.NewGCMTLS(aes)
+	} else {
+		boring.Unreachable()
+		aead, err = cipher.NewGCM(aes)
+	}
+	if err != nil {
+		panic(err)
+	}
+
+	ret := &prefixNonceAEAD{aead: aead}
+	copy(ret.nonce[:], noncePrefix)
+	return ret
+}
+
+func aeadAESGCMTLS13(key, nonceMask []byte) aead {
+	if len(nonceMask) != aeadNonceLength {
+		panic("tls: internal error: wrong nonce length")
+	}
+	aes, err := aes.NewCipher(key)
+	if err != nil {
+		panic(err)
+	}
+	aead, err := cipher.NewGCM(aes)
+	if err != nil {
+		panic(err)
+	}
+
+	ret := &xorNonceAEAD{aead: aead}
+	copy(ret.nonceMask[:], nonceMask)
+	return ret
+}
+
+func aeadChaCha20Poly1305(key, nonceMask []byte) aead {
+	if len(nonceMask) != aeadNonceLength {
+		panic("tls: internal error: wrong nonce length")
+	}
+	aead, err := chacha20poly1305.New(key)
+	if err != nil {
+		panic(err)
+	}
+
+	ret := &xorNonceAEAD{aead: aead}
+	copy(ret.nonceMask[:], nonceMask)
+	return ret
+}
+
+type constantTimeHash interface {
+	hash.Hash
+	ConstantTimeSum(b []byte) []byte
+}
+
+// cthWrapper wraps any hash.Hash that implements ConstantTimeSum, and replaces
+// with that all calls to Sum. It's used to obtain a ConstantTimeSum-based HMAC.
+type cthWrapper struct {
+	h constantTimeHash
+}
+
+func (c *cthWrapper) Size() int                   { return c.h.Size() }
+func (c *cthWrapper) BlockSize() int              { return c.h.BlockSize() }
+func (c *cthWrapper) Reset()                      { c.h.Reset() }
+func (c *cthWrapper) Write(p []byte) (int, error) { return c.h.Write(p) }
+func (c *cthWrapper) Sum(b []byte) []byte         { return c.h.ConstantTimeSum(b) }
+
+func newConstantTimeHash(h func() hash.Hash) func() hash.Hash {
+	boring.Unreachable()
+	return func() hash.Hash {
+		return &cthWrapper{h().(constantTimeHash)}
+	}
+}
+
+// tls10MAC implements the TLS 1.0 MAC function. RFC 2246, Section 6.2.3.
+func tls10MAC(h hash.Hash, out, seq, header, data, extra []byte) []byte {
+	h.Reset()
+	h.Write(seq)
+	h.Write(header)
+	h.Write(data)
+	res := h.Sum(out)
+	if extra != nil {
+		h.Write(extra)
+	}
+	return res
+}
+
+func rsaKA(version uint16) keyAgreement {
+	return rsaKeyAgreement{}
+}
+
+func ecdheECDSAKA(version uint16) keyAgreement {
+	return &ecdheKeyAgreement{
+		isRSA:   false,
+		version: version,
+	}
+}
+
+func ecdheRSAKA(version uint16) keyAgreement {
+	return &ecdheKeyAgreement{
+		isRSA:   true,
+		version: version,
+	}
+}
+
+// mutualCipherSuite returns a cipherSuite given a list of supported
+// ciphersuites and the id requested by the peer.
+func mutualCipherSuite(have []uint16, want uint16) *cipherSuite {
+	for _, id := range have {
+		if id == want {
+			return cipherSuiteByID(id)
+		}
+	}
+	return nil
+}
+
+func cipherSuiteByID(id uint16) *cipherSuite {
+	for _, cipherSuite := range cipherSuites {
+		if cipherSuite.id == id {
+			return cipherSuite
+		}
+	}
+	return nil
+}
+
+func mutualCipherSuiteTLS13(have []uint16, want uint16) *cipherSuiteTLS13 {
+	for _, id := range have {
+		if id == want {
+			return cipherSuiteTLS13ByID(id)
+		}
+	}
+	return nil
+}
+
+func cipherSuiteTLS13ByID(id uint16) *cipherSuiteTLS13 {
+	for _, cipherSuite := range cipherSuitesTLS13 {
+		if cipherSuite.id == id {
+			return cipherSuite
+		}
+	}
+	return nil
+}
+
+// A list of cipher suite IDs that are, or have been, implemented by this
+// package.
+//
+// See https://www.iana.org/assignments/tls-parameters/tls-parameters.xml
+const (
+	// TLS 1.0 - 1.2 cipher suites.
+	TLS_RSA_WITH_RC4_128_SHA                      uint16 = 0x0005
+	TLS_RSA_WITH_3DES_EDE_CBC_SHA                 uint16 = 0x000a
+	TLS_RSA_WITH_AES_128_CBC_SHA                  uint16 = 0x002f
+	TLS_RSA_WITH_AES_256_CBC_SHA                  uint16 = 0x0035
+	TLS_RSA_WITH_AES_128_CBC_SHA256               uint16 = 0x003c
+	TLS_RSA_WITH_AES_128_GCM_SHA256               uint16 = 0x009c
+	TLS_RSA_WITH_AES_256_GCM_SHA384               uint16 = 0x009d
+	TLS_ECDHE_ECDSA_WITH_RC4_128_SHA              uint16 = 0xc007
+	TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA          uint16 = 0xc009
+	TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA          uint16 = 0xc00a
+	TLS_ECDHE_RSA_WITH_RC4_128_SHA                uint16 = 0xc011
+	TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA           uint16 = 0xc012
+	TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA            uint16 = 0xc013
+	TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA            uint16 = 0xc014
+	TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256       uint16 = 0xc023
+	TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256         uint16 = 0xc027
+	TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256         uint16 = 0xc02f
+	TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256       uint16 = 0xc02b
+	TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384         uint16 = 0xc030
+	TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384       uint16 = 0xc02c
+	TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256   uint16 = 0xcca8
+	TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 uint16 = 0xcca9
+
+	// TLS 1.3 cipher suites.
+	TLS_AES_128_GCM_SHA256       uint16 = 0x1301
+	TLS_AES_256_GCM_SHA384       uint16 = 0x1302
+	TLS_CHACHA20_POLY1305_SHA256 uint16 = 0x1303
+
+	// TLS_FALLBACK_SCSV isn't a standard cipher suite but an indicator
+	// that the client is doing version fallback. See RFC 7507.
+	TLS_FALLBACK_SCSV uint16 = 0x5600
+
+	// Legacy names for the corresponding cipher suites with the correct _SHA256
+	// suffix, retained for backward compatibility.
+	TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305   = TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
+	TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305 = TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
+)