// versions that support signature algorithms, so TLS 1.2 and 1.3.
func selectSignatureScheme(vers uint16, c *Certificate, peerAlgs []SignatureScheme) (SignatureScheme, error) {
	supportedAlgs := signatureSchemesForCertificate(vers, c)
	if len(supportedAlgs) == 0 {
		return 0, unsupportedCertificateError(c)
	}
	if len(peerAlgs) == 0 && vers == VersionTLS12 {
		// For TLS 1.2, if the client didn't send signature_algorithms then we

		if cfg.CmdName != "mod download" {
			vers := mod.Version
			if mod.Path == "golang.org/toolchain" {
				// Shorten v0.0.1-go1.13.1.darwin-amd64 to go1.13.1.darwin-amd64
				_, vers, _ = strings.Cut(vers, "-")
				if i := strings.LastIndex(vers, "."); i >= 0 {
					goos, goarch, _ := strings.Cut(vers[i+1:], "-")
					vers = vers[:i] + " (" + goos + "/" + goarch + ")"
				}

			if !extData.ReadUint8LengthPrefixed(&versList) || versList.Empty() {
				return false
			}
			for !versList.Empty() {
				var vers uint16
				if !versList.ReadUint16(&vers) {
					return false
				}
				m.supportedVersions = append(m.supportedVersions, vers)
			}
		case extensionCookie:
			// RFC 8446, Section 4.2.2
			if !readUint16LengthPrefixed(&extData, &m.cookie) ||
				len(m.cookie) == 0 {

}

func randomString(n int, rand *rand.Rand) string {
	b := randomBytes(n, rand)
	return string(b)
}

func (*clientHelloMsg) Generate(rand *rand.Rand, size int) reflect.Value {
	m := &clientHelloMsg{}
	m.vers = uint16(rand.Intn(65536))
	m.random = randomBytes(32, rand)
	m.sessionId = randomBytes(rand.Intn(32), rand)
	m.cipherSuites = make([]uint16, rand.Intn(63)+1)
	for i := 0; i < len(m.cipherSuites); i++ {

	if err != nil {
		t.Fatal(err)
	}
	hello, ok := msg.(*clientHelloMsg)
	if !ok {
		t.Fatalf("unexpected message type %T", msg)
	}

	if !isBoringVersion(hello.vers) {
		t.Errorf("client vers=%#x, want %#x (TLS 1.2)", hello.vers, VersionTLS12)
	}
	for _, v := range hello.supportedVersions {
		if !isBoringVersion(v) {
			t.Errorf("client offered disallowed version %#x", v)
		}
	}

	epath, err := module.EscapePath(path)
	if err != nil {
		return nil, err
	}
	evers, err := module.EscapeVersion(strings.TrimSuffix(vers, "/go.mod"))
	if err != nil {
		return nil, err
	}
	remotePath := "/lookup/" + epath + "@" + evers
	file := c.name + remotePath

	// Fetch the data.
	// The lookupCache avoids redundant ReadCache/GetURL operations

	err := readFull(d.r, d.tmp[:13])
	if err != nil {
		return fmt.Errorf("gif: reading header: %v", err)
	}
	d.vers = string(d.tmp[:6])
	if d.vers != "GIF87a" && d.vers != "GIF89a" {
		return fmt.Errorf("gif: can't recognize format %q", d.vers)
	}
	d.width = int(d.tmp[6]) + int(d.tmp[7])<<8
	d.height = int(d.tmp[8]) + int(d.tmp[9])<<8
	if fields := d.tmp[10]; fields&fColorTable != 0 {

		_, ok := GoroutineProfile(p)
		return ok
	}))
}

func TestVersion(t *testing.T) {
	// Test that version does not contain \r or \n.
	vers := Version()
	if strings.Contains(vers, "\r") || strings.Contains(vers, "\n") {
		t.Fatalf("cr/nl in version: %q", vers)
	}
}

func TestTimediv(t *testing.T) {
	for _, tc := range []struct {
		num int64
		div int32
		ret int32
		rem int32
	}{
		{

		for _, vers := range versions {
			if len(vers) == 0 {
				consistent = false
				continue
			}
			ver := vers[0]
			if len(tops) == 0 {
				consistent = true
				topSig = ver.header
			} else {
				consistent = consistent && ver.header == topSig
			}
			tops = append(tops, vers[0])
		}

		// Check if done...

				Err: &module.InvalidVersionError{
					Version: vers,
					Err:     fmt.Errorf("malformed module path %q", path),
				},
			}
		}
		if vers != "" && module.CanonicalVersion(vers) == vers {
			if err := module.CheckPathMajor(vers, pathMajor); err != nil {
				return "", module.VersionError(module.Version{Path: path, Version: vers}, err)
			}
			return vers, nil
		}