tls

type ALPNExtension struct {
	AlpnProtocols []string
}

type CertCompressionAlgo uint16

type Certificate struct {
	Certificate [][]byte
	// PrivateKey contains the private key corresponding to the public key in
	// Leaf. This must implement crypto.Signer with an RSA, ECDSA or Ed25519 PublicKey.
	// For a server up to TLS 1.2, it can also implement crypto.Decrypter with
	// an RSA PublicKey.
	PrivateKey crypto.PrivateKey
	// SupportedSignatureAlgorithms is an optional list restricting what
	// signature algorithms the PrivateKey can be used for.
	SupportedSignatureAlgorithms []SignatureScheme
	// OCSPStaple contains an optional OCSP response which will be served
	// to clients that request it.
	OCSPStaple []byte
	// SignedCertificateTimestamps contains an optional list of Signed
	// Certificate Timestamps which will be served to clients that request it.
	SignedCertificateTimestamps [][]byte
	// Leaf is the parsed form of the leaf certificate, which may be initialized
	// using x509.ParseCertificate to reduce per-handshake processing. If nil,
	// the leaf certificate will be parsed as needed.
	Leaf *x509.Certificate
}

type CertificateRequestInfo struct {
	// AcceptableCAs contains zero or more, DER-encoded, X.501
	// Distinguished Names. These are the names of root or intermediate CAs
	// that the server wishes the returned certificate to be signed by. An
	// empty slice indicates that the server has no preference.
	AcceptableCAs [][]byte

	// SignatureSchemes lists the signature schemes that the server is
	// willing to verify.
	SignatureSchemes []SignatureScheme

	// Version is the TLS version that was negotiated for this connection.
	Version uint16
	// contains filtered or unexported fields
}

type CertificateRequestMsgTLS13 struct {
	Raw                              []byte
	OcspStapling                     bool
	Scts                             bool
	SupportedSignatureAlgorithms     []SignatureScheme
	SupportedSignatureAlgorithmsCert []SignatureScheme
	CertificateAuthorities           [][]byte
}

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
}

type ClientAuthType int

type ClientHelloID struct {
	Client string

	// Version specifies version of a mimicked clients (e.g. browsers).
	// Not used in randomized, custom handshake, and default Go.
	Version string

	// Seed is only used for randomized fingerprints to seed PRNG.
	// Must not be modified once set.
	Seed *PRNGSeed
}

type ClientHelloInfo struct {
	// CipherSuites lists the CipherSuites supported by the client (e.g.
	// TLS_AES_128_GCM_SHA256, TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256).
	CipherSuites []uint16

	// ServerName indicates the name of the server requested by the client
	// in order to support virtual hosting. ServerName is only set if the
	// client is using SNI (see RFC 4366, Section 3.1).
	ServerName string

	// SupportedCurves lists the elliptic curves supported by the client.
	// SupportedCurves is set only if the Supported Elliptic Curves
	// Extension is being used (see RFC 4492, Section 5.1.1).
	SupportedCurves []CurveID

	// SupportedPoints lists the point formats supported by the client.
	// SupportedPoints is set only if the Supported Point Formats Extension
	// is being used (see RFC 4492, Section 5.1.2).
	SupportedPoints []uint8

	// SignatureSchemes lists the signature and hash schemes that the client
	// is willing to verify. SignatureSchemes is set only if the Signature
	// Algorithms Extension is being used (see RFC 5246, Section 7.4.1.4.1).
	SignatureSchemes []SignatureScheme

	// SupportedProtos lists the application protocols supported by the client.
	// SupportedProtos is set only if the Application-Layer Protocol
	// Negotiation Extension is being used (see RFC 7301, Section 3.1).
	//
	// Servers can select a protocol by setting Config.NextProtos in a
	// GetConfigForClient return value.
	SupportedProtos []string

	// SupportedVersions lists the TLS versions supported by the client.
	// For TLS versions less than 1.3, this is extrapolated from the max
	// version advertised by the client, so values other than the greatest
	// might be rejected if used.
	SupportedVersions []uint16

	// Conn is the underlying net.Conn for the connection. Do not read
	// from, or write to, this connection; that will cause the TLS
	// connection to fail.
	Conn net.Conn
	// contains filtered or unexported fields
}

type ClientHelloSpec struct {
	CipherSuites       []uint16       // nil => default
	CompressionMethods []uint8        // nil => no compression
	Extensions         []TLSExtension // nil => no extensions

	TLSVersMin uint16 // [1.0-1.3] default: parse from .Extensions, if SupportedVersions ext is not present => 1.0
	TLSVersMax uint16 // [1.2-1.3] default: parse from .Extensions, if SupportedVersions ext is not present => 1.2

	// GreaseStyle: currently only random
	// sessionID may or may not depend on ticket; nil => random
	GetSessionID func(ticket []byte) [32]byte
}

type ClientSessionCache interface {
	// Get searches for a ClientSessionState associated with the given key.
	// On return, ok is true if one was found.
	Get(sessionKey string) (session *ClientSessionState, ok bool)

	// Put adds the ClientSessionState to the cache with the given key. It might
	// get called multiple times in a connection if a TLS 1.3 server provides
	// more than one session ticket. If called with a nil *ClientSessionState,
	// it should remove the cache entry.
	Put(sessionKey string, cs *ClientSessionState)
}

type ClientSessionState struct {
	// contains filtered or unexported fields
}

type Config struct {
	// Rand provides the source of entropy for nonces and RSA blinding.
	// If Rand is nil, TLS uses the cryptographic random reader in package
	// crypto/rand.
	// The Reader must be safe for use by multiple goroutines.
	Rand io.Reader

	// Time returns the current time as the number of seconds since the epoch.
	// If Time is nil, TLS uses time.Now.
	Time func() time.Time

	// Certificates contains one or more certificate chains to present to the
	// other side of the connection. The first certificate compatible with the
	// peer's requirements is selected automatically.
	//
	// Server configurations must set one of Certificates, GetCertificate or
	// GetConfigForClient. Clients doing client-authentication may set either
	// Certificates or GetClientCertificate.
	//
	// Note: if there are multiple Certificates, and they don't have the
	// optional field Leaf set, certificate selection will incur a significant
	// per-handshake performance cost.
	Certificates []Certificate

	// NameToCertificate maps from a certificate name to an element of
	// Certificates. Note that a certificate name can be of the form
	// '*.example.com' and so doesn't have to be a domain name as such.
	//
	// Deprecated: NameToCertificate only allows associating a single
	// certificate with a given name. Leave this field nil to let the library
	// select the first compatible chain from Certificates.
	NameToCertificate map[string]*Certificate

	// GetCertificate returns a Certificate based on the given
	// ClientHelloInfo. It will only be called if the client supplies SNI
	// information or if Certificates is empty.
	//
	// If GetCertificate is nil or returns nil, then the certificate is
	// retrieved from NameToCertificate. If NameToCertificate is nil, the
	// best element of Certificates will be used.
	GetCertificate func(*ClientHelloInfo) (*Certificate, error)

	// GetClientCertificate, if not nil, is called when a server requests a
	// certificate from a client. If set, the contents of Certificates will
	// be ignored.
	//
	// If GetClientCertificate returns an error, the handshake will be
	// aborted and that error will be returned. Otherwise
	// GetClientCertificate must return a non-nil Certificate. If
	// Certificate.Certificate is empty then no certificate will be sent to
	// the server. If this is unacceptable to the server then it may abort
	// the handshake.
	//
	// GetClientCertificate may be called multiple times for the same
	// connection if renegotiation occurs or if TLS 1.3 is in use.
	GetClientCertificate func(*CertificateRequestInfo) (*Certificate, error)

	// GetConfigForClient, if not nil, is called after a ClientHello is
	// received from a client. It may return a non-nil Config in order to
	// change the Config that will be used to handle this connection. If
	// the returned Config is nil, the original Config will be used. The
	// Config returned by this callback may not be subsequently modified.
	//
	// If GetConfigForClient is nil, the Config passed to Server() will be
	// used for all connections.
	//
	// If SessionTicketKey was explicitly set on the returned Config, or if
	// SetSessionTicketKeys was called on the returned Config, those keys will
	// be used. Otherwise, the original Config keys will be used (and possibly
	// rotated if they are automatically managed).
	GetConfigForClient func(*ClientHelloInfo) (*Config, error)

	// VerifyPeerCertificate, if not nil, is called after normal
	// certificate verification by either a TLS client or server. It
	// receives the raw ASN.1 certificates provided by the peer and also
	// any verified chains that normal processing found. If it returns a
	// non-nil error, the handshake is aborted and that error results.
	//
	// If normal verification fails then the handshake will abort before
	// considering this callback. If normal verification is disabled by
	// setting InsecureSkipVerify, or (for a server) when ClientAuth is
	// RequestClientCert or RequireAnyClientCert, then this callback will
	// be considered but the verifiedChains argument will always be nil.
	VerifyPeerCertificate func(rawCerts [][]byte, verifiedChains [][]*x509.Certificate) error

	// VerifyConnection, if not nil, is called after normal certificate
	// verification and after VerifyPeerCertificate by either a TLS client
	// or server. If it returns a non-nil error, the handshake is aborted
	// and that error results.
	//
	// If normal verification fails then the handshake will abort before
	// considering this callback. This callback will run for all connections
	// regardless of InsecureSkipVerify or ClientAuth settings.
	VerifyConnection func(ConnectionState) error

	// RootCAs defines the set of root certificate authorities
	// that clients use when verifying server certificates.
	// If RootCAs is nil, TLS uses the host's root CA set.
	RootCAs *x509.CertPool

	// NextProtos is a list of supported application level protocols, in
	// order of preference. If both peers support ALPN, the selected
	// protocol will be one from this list, and the connection will fail
	// if there is no mutually supported protocol. If NextProtos is empty
	// or the peer doesn't support ALPN, the connection will succeed and
	// ConnectionState.NegotiatedProtocol will be empty.
	NextProtos []string

	// ServerName is used to verify the hostname on the returned
	// certificates unless InsecureSkipVerify is given. It is also included
	// in the client's handshake to support virtual hosting unless it is
	// an IP address.
	ServerName string

	// ClientAuth determines the server's policy for
	// TLS Client Authentication. The default is NoClientCert.
	ClientAuth ClientAuthType

	// ClientCAs defines the set of root certificate authorities
	// that servers use if required to verify a client certificate
	// by the policy in ClientAuth.
	ClientCAs *x509.CertPool

	// InsecureSkipVerify controls whether a client verifies the server's
	// certificate chain and host name. If InsecureSkipVerify is true, crypto/tls
	// accepts any certificate presented by the server and any host name in that
	// certificate. In this mode, TLS is susceptible to machine-in-the-middle
	// attacks unless custom verification is used. This should be used only for
	// testing or in combination with VerifyConnection or VerifyPeerCertificate.
	InsecureSkipVerify bool

	// CipherSuites is a list of enabled TLS 1.0–1.2 cipher suites. The order of
	// the list is ignored. Note that TLS 1.3 ciphersuites are not configurable.
	//
	// If CipherSuites is nil, a safe default list is used. The default cipher
	// suites might change over time.
	CipherSuites []uint16

	// PreferServerCipherSuites is a legacy field and has no effect.
	//
	// It used to control whether the server would follow the client's or the
	// server's preference. Servers now select the best mutually supported
	// cipher suite based on logic that takes into account inferred client
	// hardware, server hardware, and security.
	//
	// Deprecated: PreferServerCipherSuites is ignored.
	PreferServerCipherSuites bool

	// SessionTicketsDisabled may be set to true to disable session ticket and
	// PSK (resumption) support. Note that on clients, session ticket support is
	// also disabled if ClientSessionCache is nil.
	SessionTicketsDisabled bool

	// SessionTicketKey is used by TLS servers to provide session resumption.
	// See RFC 5077 and the PSK mode of RFC 8446. If zero, it will be filled
	// with random data before the first server handshake.
	//
	// Deprecated: if this field is left at zero, session ticket keys will be
	// automatically rotated every day and dropped after seven days. For
	// customizing the rotation schedule or synchronizing servers that are
	// terminating connections for the same host, use SetSessionTicketKeys.
	SessionTicketKey [32]byte

	// ClientSessionCache is a cache of ClientSessionState entries for TLS
	// session resumption. It is only used by clients.
	ClientSessionCache ClientSessionCache

	// MinVersion contains the minimum TLS version that is acceptable.
	//
	// By default, TLS 1.2 is currently used as the minimum when acting as a
	// client, and TLS 1.0 when acting as a server. TLS 1.0 is the minimum
	// supported by this package, both as a client and as a server.
	//
	// The client-side default can temporarily be reverted to TLS 1.0 by
	// including the value "x509sha1=1" in the GODEBUG environment variable.
	// Note that this option will be removed in Go 1.19 (but it will still be
	// possible to set this field to VersionTLS10 explicitly).
	MinVersion uint16

	// MaxVersion contains the maximum TLS version that is acceptable.
	//
	// By default, the maximum version supported by this package is used,
	// which is currently TLS 1.3.
	MaxVersion uint16

	// CurvePreferences contains the elliptic curves that will be used in
	// an ECDHE handshake, in preference order. If empty, the default will
	// be used. The client will use the first preference as the type for
	// its key share in TLS 1.3. This may change in the future.
	CurvePreferences []CurveID

	// DynamicRecordSizingDisabled disables adaptive sizing of TLS records.
	// When true, the largest possible TLS record size is always used. When
	// false, the size of TLS records may be adjusted in an attempt to
	// improve latency.
	DynamicRecordSizingDisabled bool

	// Renegotiation controls what types of renegotiation are supported.
	// The default, none, is correct for the vast majority of applications.
	Renegotiation RenegotiationSupport

	// KeyLogWriter optionally specifies a destination for TLS master secrets
	// in NSS key log format that can be used to allow external programs
	// such as Wireshark to decrypt TLS connections.
	// See https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/Key_Log_Format.
	// Use of KeyLogWriter compromises security and should only be
	// used for debugging.
	KeyLogWriter io.Writer
	// contains filtered or unexported fields
}

type Conn struct {
	ClientHello string
	// contains filtered or unexported fields
}

type ConnectionState struct {
	// Version is the TLS version used by the connection (e.g. VersionTLS12).
	Version uint16

	// HandshakeComplete is true if the handshake has concluded.
	HandshakeComplete bool

	// DidResume is true if this connection was successfully resumed from a
	// previous session with a session ticket or similar mechanism.
	DidResume bool

	// CipherSuite is the cipher suite negotiated for the connection (e.g.
	// TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, TLS_AES_128_GCM_SHA256).
	CipherSuite uint16

	// NegotiatedProtocol is the application protocol negotiated with ALPN.
	NegotiatedProtocol string

	// NegotiatedProtocolIsMutual used to indicate a mutual NPN negotiation.
	//
	// Deprecated: this value is always true.
	NegotiatedProtocolIsMutual bool

	// ServerName is the value of the Server Name Indication extension sent by
	// the client. It's available both on the server and on the client side.
	ServerName string

	// PeerCertificates are the parsed certificates sent by the peer, in the
	// order in which they were sent. The first element is the leaf certificate
	// that the connection is verified against.
	//
	// On the client side, it can't be empty. On the server side, it can be
	// empty if Config.ClientAuth is not RequireAnyClientCert or
	// RequireAndVerifyClientCert.
	PeerCertificates []*x509.Certificate

	// VerifiedChains is a list of one or more chains where the first element is
	// PeerCertificates[0] and the last element is from Config.RootCAs (on the
	// client side) or Config.ClientCAs (on the server side).
	//
	// On the client side, it's set if Config.InsecureSkipVerify is false. On
	// the server side, it's set if Config.ClientAuth is VerifyClientCertIfGiven
	// (and the peer provided a certificate) or RequireAndVerifyClientCert.
	VerifiedChains [][]*x509.Certificate

	// SignedCertificateTimestamps is a list of SCTs provided by the peer
	// through the TLS handshake for the leaf certificate, if any.
	SignedCertificateTimestamps [][]byte

	// OCSPResponse is a stapled Online Certificate Status Protocol (OCSP)
	// response provided by the peer for the leaf certificate, if any.
	OCSPResponse []byte

	// TLSUnique contains the "tls-unique" channel binding value (see RFC 5929,
	// Section 3). This value will be nil for TLS 1.3 connections and for all
	// resumed connections.
	//
	// Deprecated: there are conditions in which this value might not be unique
	// to a connection. See the Security Considerations sections of RFC 5705 and
	// RFC 7627, and https://mitls.org/pages/attacks/3SHAKE#channelbindings.
	TLSUnique []byte
	// contains filtered or unexported fields
}

type CookieExtension struct {
	Cookie []byte
}

type CurveID uint16

type Dialer struct {
	// NetDialer is the optional dialer to use for the TLS connections'
	// underlying TCP connections.
	// A nil NetDialer is equivalent to the net.Dialer zero value.
	NetDialer *net.Dialer

	// Config is the TLS configuration to use for new connections.
	// A nil configuration is equivalent to the zero
	// configuration; see the documentation of Config for the
	// defaults.
	Config *Config
}

type EcdheParameters interface {
	// contains filtered or unexported methods
}

type FakeChannelIDExtension struct {
}

type FakeRecordSizeLimitExtension struct {
	Limit uint16
}

type Fingerprinter struct {
	// KeepPSK will ensure that the PreSharedKey extension is passed along into the resulting ClientHelloSpec as-is
	KeepPSK bool
	// AllowBluntMimicry will ensure that unknown extensions are
	// passed along into the resulting ClientHelloSpec as-is
	// It will not ensure that the PSK is passed along, if you require that, use KeepPSK
	// WARNING: there could be numerous subtle issues with ClientHelloSpecs
	// that are generated with this flag which could compromise security and/or mimicry
	AllowBluntMimicry bool
	// AlwaysAddPadding will always add a UtlsPaddingExtension with BoringPaddingStyle
	// at the end of the extensions list if it isn't found in the fingerprinted hello.
	// This could be useful in scenarios where the hello you are fingerprinting does not
	// have any padding, but you suspect that other changes you make to the final hello
	// (including things like different SNI lengths) would cause padding to be necessary
	AlwaysAddPadding bool
}

type FinishedHash struct {
	Client hash.Hash
	Server hash.Hash

	// Prior to TLS 1.2, an additional MD5 hash is required.
	ClientMD5 hash.Hash
	ServerMD5 hash.Hash

	// In TLS 1.2, a full buffer is sadly required.
	Buffer []byte

	Version uint16
	Prf     func(result, secret, label, seed []byte)
}

type GenericExtension struct {
	Id   uint16
	Data []byte
}

type KeyShare struct {
	Group CurveID
	Data  []byte
}

type KeyShareExtension struct {
	KeyShares []KeyShare
}

type KeyShares []KeyShare

type NPNExtension struct {
	NextProtos []string
}

type PRNGSeed [PRNGSeedLength]byte

type PSKKeyExchangeModesExtension struct {
	Modes []uint8
}

type PubCipherSuite 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) interface{}
	Mac    func(macKey []byte) hash.Hash
	Aead   func(key, fixedNonce []byte) aead
}

type PubCipherSuiteTLS13 struct {
	Id     uint16
	KeyLen int
	Aead   func(key, fixedNonce []byte) aead
	Hash   crypto.Hash
}

type PubClientHandshakeState struct {
	C            *Conn
	ServerHello  *PubServerHelloMsg
	Hello        *PubClientHelloMsg
	MasterSecret []byte
	Session      *ClientSessionState

	State12 TLS12OnlyState
	State13 TLS13OnlyState
	// contains filtered or unexported fields
}

type PubClientHelloMsg struct {
	Raw                          []byte
	Vers                         uint16
	Random                       []byte
	SessionId                    []byte
	CipherSuites                 []uint16
	CompressionMethods           []uint8
	NextProtoNeg                 bool
	ServerName                   string
	OcspStapling                 bool
	Scts                         bool
	Ems                          bool // [uTLS] actually implemented due to its prevalence
	SupportedCurves              []CurveID
	SupportedPoints              []uint8
	TicketSupported              bool
	SessionTicket                []uint8
	SupportedSignatureAlgorithms []SignatureScheme
	SecureRenegotiation          []byte
	SecureRenegotiationSupported bool
	AlpnProtocols                []string

	// 1.3
	SupportedSignatureAlgorithmsCert []SignatureScheme
	SupportedVersions                []uint16
	Cookie                           []byte
	KeyShares                        []KeyShare
	EarlyData                        bool
	PskModes                         []uint8
	PskIdentities                    []pskIdentity
	PskBinders                       [][]byte
}

type PubServerHelloMsg struct {
	Raw                          []byte
	Vers                         uint16
	Random                       []byte
	SessionId                    []byte
	CipherSuite                  uint16
	CompressionMethod            uint8
	NextProtoNeg                 bool
	NextProtos                   []string
	OcspStapling                 bool
	Scts                         [][]byte
	Ems                          bool
	TicketSupported              bool
	SecureRenegotiation          []byte
	SecureRenegotiationSupported bool
	AlpnProtocol                 string

	// 1.3
	SupportedVersion        uint16
	ServerShare             keyShare
	SelectedIdentityPresent bool
	SelectedIdentity        uint16
	Cookie                  []byte  // HelloRetryRequest extension
	SelectedGroup           CurveID // HelloRetryRequest extension

}

type RecordHeaderError struct {
	// Msg contains a human readable string that describes the error.
	Msg string
	// RecordHeader contains the five bytes of TLS record header that
	// triggered the error.
	RecordHeader [5]byte
	// Conn provides the underlying net.Conn in the case that a client
	// sent an initial handshake that didn't look like TLS.
	// It is nil if there's already been a handshake or a TLS alert has
	// been written to the connection.
	Conn net.Conn
}

type RenegotiationInfoExtension struct {
	// Renegotiation field limits how many times client will perform renegotiation: no limit, once, or never.
	// The extension still will be sent, even if Renegotiation is set to RenegotiateNever.
	Renegotiation RenegotiationSupport
}

type RenegotiationSupport int

type Roller struct {
	HelloIDs            []ClientHelloID
	HelloIDMu           sync.Mutex
	WorkingHelloID      *ClientHelloID
	TcpDialTimeout      time.Duration
	TlsHandshakeTimeout time.Duration
	// contains filtered or unexported fields
}

type SCTExtension struct {
}

type SNIExtension struct {
	ServerName string // not an array because go crypto/tls doesn't support multiple SNIs
}

type SessionTicketExtension struct {
	Session *ClientSessionState
}

type SignatureAlgorithmsExtension struct {
	SupportedSignatureAlgorithms []SignatureScheme
}

type SignatureScheme uint16

type StatusRequestExtension struct {
}

type SupportedCurvesExtension struct {
	Curves []CurveID
}

type SupportedPointsExtension struct {
	SupportedPoints []uint8
}

type SupportedVersionsExtension struct {
	Versions []uint16
}

type TLS12OnlyState struct {
	FinishedHash FinishedHash
	Suite        PubCipherSuite
}

type TLS13OnlyState struct {
	Suite         *PubCipherSuiteTLS13
	EcdheParams   EcdheParameters
	EarlySecret   []byte
	BinderKey     []byte
	CertReq       *CertificateRequestMsgTLS13
	UsingPSK      bool
	SentDummyCCS  bool
	Transcript    hash.Hash
	TrafficSecret []byte // client_application_traffic_secret_0
}

type TLSExtension interface {
	Len() int // includes header

	// Read reads up to len(p) bytes into p.
	// It returns the number of bytes read (0 <= n <= len(p)) and any error encountered.
	Read(p []byte) (n int, err error) // implements io.Reader
	// contains filtered or unexported methods
}

type TicketKey struct {
	// KeyName is an opaque byte string that serves to identify the session
	// ticket key. It's exposed as plaintext in every session ticket.
	KeyName [ticketKeyNameLen]byte
	AesKey  [16]byte
	HmacKey [16]byte
}

type TicketKeys []TicketKey

type UConn struct {
	*Conn

	Extensions    []TLSExtension
	ClientHelloID ClientHelloID

	ClientHelloBuilt bool
	HandshakeState   PubClientHandshakeState

	// sessionID may or may not depend on ticket; nil => random
	GetSessionID func(ticket []byte) [32]byte
	// contains filtered or unexported fields
}

type UtlsCompressCertExtension struct {
	Algorithms []CertCompressionAlgo
}

type UtlsExtendedMasterSecretExtension struct {
}

type UtlsGREASEExtension struct {
	Value uint16
	Body  []byte // in Chrome first grease has empty body, second grease has a single zero byte
}

type UtlsPaddingExtension struct {
	PaddingLen int
	WillPad    bool // set to false to disable extension

	// Functor for deciding on padding length based on unpadded ClientHello length.
	// If willPad is false, then this extension should not be included.
	GetPaddingLen func(clientHelloUnpaddedLen int) (paddingLen int, willPad bool)
}