gotls

package
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 Go to latest Published: Feb 14, 2019 License: BSD-3-Clause, BSD-3-Clause Imports: 33 Imported by: 0

README

Codebase from golang TLS package

Note that the package gotls comes from the golang tls package. I have modified it to export some methods that I wanted to use, in order to hook into and have more control of the TLS handshake steps.

I also introduced a few trivial methods to make my life easier. I have marked areas where I changed or introduced something with comments such as below to help identify the changes

//--changed by dayo
//--introduced by dayo

All credit to the Go team who gave us an incredible language and TLS implementation! Thank you so much.

This code is released under BSD 3-Clause License, similar to the golang language, which is released under a BSD-style license.

Documentation

Index

Constants

View Source 
const (
	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    uint16 = 0xcca8
	TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305  uint16 = 0xcca9

	// TLS_FALLBACK_SCSV isn't a standard cipher suite but an indicator
	// that the client is doing version fallback. See
	// https://tools.ietf.org/html/rfc7507.
	TLS_FALLBACK_SCSV uint16 = 0x5600
)

A list of cipher suite IDs that are, or have been, implemented by this package.

Taken from http://www.iana.org/assignments/tls-parameters/tls-parameters.xml

View Source 
const (
	VersionSSL30 = 0x0300
	VersionTLS10 = 0x0301
	VersionTLS11 = 0x0302
	VersionTLS12 = 0x0303
)
View Source 
const (

	//RecordTypeHandshake exported type
	RecordTypeHandshake recordType = 22
)

Variables

This section is empty.

Functions

func MakeClientHello 

func MakeClientHello(config *Config) (*clientHelloMsg, error)

MakeClientHello returns a Client Hello Message --changed by dayo

Types

type Certificate 

type Certificate struct {
	Certificate [][]byte
	// PrivateKey contains the private key corresponding to the public key
	// in Leaf. For a server, this must implement crypto.Signer and/or
	// crypto.Decrypter, with an RSA or ECDSA PublicKey. For a client
	// (performing client authentication), this must be a crypto.Signer
	// with an RSA or ECDSA PublicKey.
	PrivateKey crypto.PrivateKey
	// 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 for TLS clients doing client authentication. If nil, the
	// leaf certificate will be parsed as needed.
	Leaf *x509.Certificate
}

A Certificate is a chain of one or more certificates, leaf first.

type CertificateRequestInfo 

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
}

CertificateRequestInfo contains information from a server's CertificateRequest message, which is used to demand a certificate and proof of control from a client.

type ClientAuthType 

type ClientAuthType int

ClientAuthType declares the policy the server will follow for TLS Client Authentication. 

const (
	NoClientCert ClientAuthType = iota
	RequestClientCert
	RequireAnyClientCert
	VerifyClientCertIfGiven
	RequireAndVerifyClientCert
)

type ClientHelloInfo 

type ClientHelloInfo struct {
	// CipherSuites lists the CipherSuites supported by the client (e.g.
	// TLS_RSA_WITH_RC4_128_SHA).
	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
	// http://tools.ietf.org/html/rfc4366#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
	// http://tools.ietf.org/html/rfc4492#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
	// http://tools.ietf.org/html/rfc4492#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
	// https://tools.ietf.org/html/rfc5246#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
	// https://tools.ietf.org/html/rfc7301#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
}

ClientHelloInfo contains information from a ClientHello message in order to guide certificate selection in the GetCertificate callback.

type ClientSessionCache 

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.
	Put(sessionKey string, cs *ClientSessionState)
}

ClientSessionCache is a cache of ClientSessionState objects that can be used by a client to resume a TLS session with a given server. ClientSessionCache implementations should expect to be called concurrently from different goroutines. Only ticket-based resumption is supported, not SessionID-based resumption.

func NewLRUClientSessionCache 

func NewLRUClientSessionCache(capacity int) ClientSessionCache

NewLRUClientSessionCache returns a ClientSessionCache with the given capacity that uses an LRU strategy. If capacity is < 1, a default capacity is used instead.

type ClientSessionState 

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

ClientSessionState contains the state needed by clients to resume TLS sessions.

type Config 

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. Server configurations must include
	// at least one certificate or else set GetCertificate. Clients doing
	// client-authentication may set either Certificates or
	// GetClientCertificate.
	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.
	// See Config.BuildNameToCertificate
	// The nil value causes the first element of Certificates to be used
	// for all connections.
	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
	// first 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.
	//
	// Uniquely for the fields in the returned Config, session ticket keys
	// will be duplicated from the original Config if not set.
	// Specifically, if SetSessionTicketKeys was called on the original
	// config but not on the returned config then the ticket keys from the
	// original config will be copied into the new config before use.
	// Otherwise, if SessionTicketKey was set in the original config but
	// not in the returned config then it will be copied into the returned
	// config before use. If neither of those cases applies then the key
	// material from the returned config will be used for session tickets.
	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

	// 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.
	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, TLS accepts any certificate
	// presented by the server and any host name in that certificate.
	// In this mode, TLS is susceptible to man-in-the-middle attacks.
	// This should be used only for testing.
	InsecureSkipVerify bool

	// CipherSuites is a list of supported cipher suites. If CipherSuites
	// is nil, TLS uses a list of suites supported by the implementation.
	CipherSuites []uint16

	// PreferServerCipherSuites controls whether the server selects the
	// client's most preferred ciphersuite, or the server's most preferred
	// ciphersuite. If true then the server's preference, as expressed in
	// the order of elements in CipherSuites, is used.
	PreferServerCipherSuites bool

	// SessionTicketsDisabled may be set to true to disable session ticket
	// (resumption) support.
	SessionTicketsDisabled bool

	// SessionTicketKey is used by TLS servers to provide session
	// resumption. See RFC 5077. If zero, it will be filled with
	// random data before the first server handshake.
	//
	// If multiple servers are terminating connections for the same host
	// they should all have the same SessionTicketKey. If the
	// SessionTicketKey leaks, previously recorded and future TLS
	// connections using that key are compromised.
	SessionTicketKey [32]byte

	// ClientSessionCache is a cache of ClientSessionState entries for TLS
	// session resumption.
	ClientSessionCache ClientSessionCache

	// MinVersion contains the minimum SSL/TLS version that is acceptable.
	// If zero, then TLS 1.0 is taken as the minimum.
	MinVersion uint16

	// MaxVersion contains the maximum SSL/TLS version that is acceptable.
	// If zero, then the maximum version supported by this package is used,
	// which is currently TLS 1.2.
	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.
	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
}

A Config structure is used to configure a TLS client or server. After one has been passed to a TLS function it must not be modified. A Config may be reused; the tls package will also not modify it.

func (*Config) BuildNameToCertificate 

func (c *Config) BuildNameToCertificate()

BuildNameToCertificate parses c.Certificates and builds c.NameToCertificate from the CommonName and SubjectAlternateName fields of each of the leaf certificates.

func (*Config) Clone 

func (c *Config) Clone() *Config

Clone returns a shallow clone of c. It is safe to clone a Config that is being used concurrently by a TLS client or server.

func (*Config) SetSessionTicketKeys 

func (c *Config) SetSessionTicketKeys(keys [][32]byte)

SetSessionTicketKeys updates the session ticket keys for a server. The first key will be used when creating new tickets, while all keys can be used for decrypting tickets. It is safe to call this function while the server is running in order to rotate the session ticket keys. The function will panic if keys is empty.

type Conn 

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

A Conn represents a secured connection. It implements the net.Conn interface.

func MakeClientConnection 

func MakeClientConnection(rawConn net.Conn, config *Config) *Conn

MakeClientConnection returns a TLS connection using the raw connection and the configuration --changed by dayo

func (*Conn) Close 

func (c *Conn) Close() error

Close closes the connection.

func (*Conn) CloseWrite 

func (c *Conn) CloseWrite() error

CloseWrite shuts down the writing side of the connection. It should only be called once the handshake has completed and does not call CloseWrite on the underlying connection. Most callers should just use Close.

func (*Conn) ConnectionState 

func (c *Conn) ConnectionState() ConnectionState

ConnectionState returns basic TLS details about the connection.

func (*Conn) Handshake 

func (c *Conn) Handshake() error

Handshake runs the client or server handshake protocol if it has not yet been run. Most uses of this package need not call Handshake explicitly: the first Read or Write will call it automatically.

func (*Conn) LocalAddr 

func (c *Conn) LocalAddr() net.Addr

LocalAddr returns the local network address.

func (*Conn) OCSPResponse 

func (c *Conn) OCSPResponse() []byte

OCSPResponse returns the stapled OCSP response from the TLS server, if any. (Only valid for client connections.)

func (*Conn) Read 

func (c *Conn) Read(b []byte) (n int, err error)

Read can be made to time out and return a net.Error with Timeout() == true after a fixed time limit; see SetDeadline and SetReadDeadline.

func (*Conn) ReadServerCertificate 

func (c *Conn) ReadServerCertificate() (tlsmodel.CertificateMessage, error)

ReadServerCertificate does exactly what it says --introduced by dayo

func (*Conn) ReadServerHello 

func (c *Conn) ReadServerHello() (tlsmodel.ServerHelloMessage, error)

ReadServerHello does exactly what it says --introduced by dayo

func (*Conn) ReadServerKeyExchange 

func (c *Conn) ReadServerKeyExchange() (tlsmodel.ServerKeyExchangeMsg, error)

ReadServerKeyExchange does exactly what it says - skips certificate/certificate status messages --introduced by dayo

func (*Conn) RemoteAddr 

func (c *Conn) RemoteAddr() net.Addr

RemoteAddr returns the remote network address.

func (*Conn) SetDeadline 

func (c *Conn) SetDeadline(t time.Time) error

SetDeadline sets the read and write deadlines associated with the connection. A zero value for t means Read and Write will not time out. After a Write has timed out, the TLS state is corrupt and all future writes will return the same error.

func (*Conn) SetReadDeadline 

func (c *Conn) SetReadDeadline(t time.Time) error

SetReadDeadline sets the read deadline on the underlying connection. A zero value for t means Read will not time out.

func (*Conn) SetWriteDeadline 

func (c *Conn) SetWriteDeadline(t time.Time) error

SetWriteDeadline sets the write deadline on the underlying connection. A zero value for t means Write will not time out. After a Write has timed out, the TLS state is corrupt and all future writes will return the same error.

func (*Conn) VerifyHostname 

func (c *Conn) VerifyHostname(host string) error

VerifyHostname checks that the peer certificate chain is valid for connecting to host. If so, it returns nil; if not, it returns an error describing the problem.

func (*Conn) Write 

func (c *Conn) Write(b []byte) (int, error)

Write writes data to the connection.

func (*Conn) WriteRecord 

func (c *Conn) WriteRecord(typ recordType, data []byte) (int, error)

WriteRecord writes a TLS record with the given type and payload to the connection and updates the record layer state. L < c.out.Mutex. --changed by dayo

type ConnectionState 

type ConnectionState struct {
	Version                     uint16                // TLS version used by the connection (e.g. VersionTLS12)
	HandshakeComplete           bool                  // TLS handshake is complete
	DidResume                   bool                  // connection resumes a previous TLS connection
	CipherSuite                 uint16                // cipher suite in use (TLS_RSA_WITH_RC4_128_SHA, ...)
	NegotiatedProtocol          string                // negotiated next protocol (not guaranteed to be from Config.NextProtos)
	NegotiatedProtocolIsMutual  bool                  // negotiated protocol was advertised by server (client side only)
	ServerName                  string                // server name requested by client, if any (server side only)
	PeerCertificates            []*x509.Certificate   // certificate chain presented by remote peer
	VerifiedChains              [][]*x509.Certificate // verified chains built from PeerCertificates
	SignedCertificateTimestamps [][]byte              // SCTs from the server, if any
	OCSPResponse                []byte                // stapled OCSP response from server, if any

	// TLSUnique contains the "tls-unique" channel binding value (see RFC
	// 5929, section 3). For resumed sessions this value will be nil
	// because resumption does not include enough context (see
	// https://mitls.org/pages/attacks/3SHAKE#channelbindings). This will
	// change in future versions of Go once the TLS master-secret fix has
	// been standardized and implemented.
	TLSUnique []byte
}

ConnectionState records basic TLS details about the connection.

type CurveID 

type CurveID uint16

CurveID is the type of a TLS identifier for an elliptic curve. See http://www.iana.org/assignments/tls-parameters/tls-parameters.xml#tls-parameters-8 

const (
	CurveP256 CurveID = 23
	CurveP384 CurveID = 24
	CurveP521 CurveID = 25
	X25519    CurveID = 29
)

type RecordHeaderError 

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
}

RecordHeaderError results when a TLS record header is invalid.

func (RecordHeaderError) Error 

func (e RecordHeaderError) Error() string

type RenegotiationSupport 

type RenegotiationSupport int

RenegotiationSupport enumerates the different levels of support for TLS renegotiation. TLS renegotiation is the act of performing subsequent handshakes on a connection after the first. This significantly complicates the state machine and has been the source of numerous, subtle security issues. Initiating a renegotiation is not supported, but support for accepting renegotiation requests may be enabled.

Even when enabled, the server may not change its identity between handshakes (i.e. the leaf certificate must be the same). Additionally, concurrent handshake and application data flow is not permitted so renegotiation can only be used with protocols that synchronise with the renegotiation, such as HTTPS. 

const (
	// RenegotiateNever disables renegotiation.
	RenegotiateNever RenegotiationSupport = iota

	// RenegotiateOnceAsClient allows a remote server to request
	// renegotiation once per connection.
	RenegotiateOnceAsClient

	// RenegotiateFreelyAsClient allows a remote server to repeatedly
	// request renegotiation.
	RenegotiateFreelyAsClient
)

type SignatureScheme 

type SignatureScheme uint16

SignatureScheme identifies a signature algorithm supported by TLS. See https://tools.ietf.org/html/draft-ietf-tls-tls13-18#section-4.2.3. 

const (
	PKCS1WithSHA1   SignatureScheme = 0x0201
	PKCS1WithSHA256 SignatureScheme = 0x0401
	PKCS1WithSHA384 SignatureScheme = 0x0501
	PKCS1WithSHA512 SignatureScheme = 0x0601

	PSSWithSHA256 SignatureScheme = 0x0804
	PSSWithSHA384 SignatureScheme = 0x0805
	PSSWithSHA512 SignatureScheme = 0x0806

	ECDSAWithP256AndSHA256 SignatureScheme = 0x0403
	ECDSAWithP384AndSHA384 SignatureScheme = 0x0503
	ECDSAWithP521AndSHA512 SignatureScheme = 0x0603

	// Legacy signature and hash algorithms for TLS 1.2.
	ECDSAWithSHA1 SignatureScheme = 0x0203
)

Source Files

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