tls

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 Go to latest Published: Dec 20, 2024 License: BSD-3-Clause Imports: 9 Imported by: 0

Documentation

Overview

Package tls partially implements TLS 1.2, as specified in RFC 5246, and TLS 1.3, as specified in RFC 8446.

Index

Constants

This section is empty.

Variables

This section is empty.

Functions

func CipherSuiteName added in v0.33.0 

func CipherSuiteName(id uint16) string

CipherSuiteName returns the standard name for the passed cipher suite ID

Not Implemented.

func Client 

func Client(conn net.Conn, config *Config) *net.TLSConn

Client returns a new TLS client side connection using conn as the underlying transport. The config cannot be nil: users must set either ServerName or InsecureSkipVerify in the config.

func Dial 

func Dial(network, addr string, config *Config) (*net.TLSConn, error)

Dial connects to the given network address using net.Dial and then initiates a TLS handshake, returning the resulting TLS connection. Dial interprets a nil configuration as equivalent to the zero configuration; see the documentation of Config for the defaults.

func DialWithDialer 

func DialWithDialer(dialer *net.Dialer, network, addr string, config *Config) (*net.TLSConn, error)

DialWithDialer connects to the given network address using dialer.Dial and then initiates a TLS handshake, returning the resulting TLS connection. Any timeout or deadline given in the dialer apply to connection and TLS handshake as a whole.

DialWithDialer interprets a nil configuration as equivalent to the zero configuration; see the documentation of Config for the defaults.

DialWithDialer uses context.Background internally; to specify the context, use Dialer.DialContext with NetDialer set to the desired dialer.

func NewListener 

func NewListener(inner net.Listener, config *Config) net.Listener

NewListener creates a Listener which accepts connections from an inner Listener and wraps each connection with Server. The configuration config must be non-nil and must include at least one certificate or else set GetCertificate.

Types

type Certificate 

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
}

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

func LoadX509KeyPair 

func LoadX509KeyPair(certFile, keyFile string) (Certificate, error)

LoadX509KeyPair reads and parses a public/private key pair from a pair of files. The files must contain PEM encoded data. The certificate file may contain intermediate certificates following the leaf certificate to form a certificate chain. On successful return, Certificate.Leaf will be nil because the parsed form of the certificate is not retained.

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

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

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.

type ClientHelloInfo 

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
}

ClientHelloInfo contains information from a ClientHello message in order to guide application logic in the GetCertificate and GetConfigForClient callbacks.

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. 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)
}

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. Up to TLS 1.2, only ticket-based resumption is supported, not SessionID-based resumption. In TLS 1.3 they were merged into PSK modes, which are supported via this interface.

type ClientSessionState 

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

ClientSessionState contains the state needed by a client to resume a previous TLS session.

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. 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.
	//
	// Once a Certificate is returned it should not be modified.
	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.
	//
	// Once a Certificate is returned it should not be modified.
	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 (on the
	// client when InsecureSkipVerify is set, or on a server when ClientAuth is
	// RequestClientCert or RequireAnyClientCert), then this callback will be
	// considered but the verifiedChains argument will always be nil. When
	// ClientAuth is NoClientCert, this callback is not called on the server.
	// rawCerts may be empty on the server if ClientAuth is RequestClientCert or
	// VerifyClientCertIfGiven.
	//
	// This callback is not invoked on resumed connections, as certificates are
	// not re-verified on resumption.
	//
	// verifiedChains and its contents should not be modified.
	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,
	// including resumptions, 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

	// UnwrapSession is called on the server to turn a ticket/identity
	// previously produced by [WrapSession] into a usable session.
	//
	// UnwrapSession will usually either decrypt a session state in the ticket
	// (for example with [Config.EncryptTicket]), or use the ticket as a handle
	// to recover a previously stored state. It must use [ParseSessionState] to
	// deserialize the session state.
	//
	// If UnwrapSession returns an error, the connection is terminated. If it
	// returns (nil, nil), the session is ignored. crypto/tls may still choose
	// not to resume the returned session.
	UnwrapSession func(identity []byte, cs ConnectionState) (*SessionState, error)

	// WrapSession is called on the server to produce a session ticket/identity.
	//
	// WrapSession must serialize the session state with [SessionState.Bytes].
	// It may then encrypt the serialized state (for example with
	// [Config.DecryptTicket]) and use it as the ticket, or store the state and
	// return a handle for it.
	//
	// If WrapSession returns an error, the connection is terminated.
	//
	// Warning: the return value will be exposed on the wire and to clients in
	// plaintext. The application is in charge of encrypting and authenticating
	// it (and rotating keys) or returning high-entropy identifiers. Failing to
	// do so correctly can compromise current, previous, and future connections
	// depending on the protocol version.
	WrapSession func(ConnectionState, *SessionState) ([]byte, error)

	// 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
}

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.

type ConnectionState 

type ConnectionState struct {
	// TINYGO: empty; TLS connection offloaded to device
	//
	// Minimum (empty) fields for fortio.org/log http logging and others
	// to compile and run.
	PeerCertificates []*x509.Certificate
	CipherSuite      uint16
}

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 https://www.iana.org/assignments/tls-parameters/tls-parameters.xml#tls-parameters-8.

In TLS 1.3, this type is called NamedGroup, but at this time this library only supports Elliptic Curve based groups. See RFC 8446, Section 4.2.7.

type Dialer 

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
}

Dialer dials TLS connections given a configuration and a Dialer for the underlying connection.

func (*Dialer) DialContext 

func (d *Dialer) DialContext(ctx context.Context, network, addr string) (net.Conn, error)

DialContext connects to the given network address and initiates a TLS handshake, returning the resulting TLS connection.

The provided Context must be non-nil. If the context expires before the connection is complete, an error is returned. Once successfully connected, any expiration of the context will not affect the connection.

The returned Conn, if any, will always be of type *Conn.

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.

Renegotiation is not defined in TLS 1.3.

type SessionState 

type SessionState struct {
}

A SessionState is a resumable session.

type SignatureScheme 

type SignatureScheme uint16

SignatureScheme identifies a signature algorithm supported by TLS. See RFC 8446, Section 4.2.3.

Notes

Bugs

Source Files

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