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- // Copyright 2009 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/rand"
- "crypto/rsa"
- "crypto/x509"
- "io"
- "io/ioutil"
- "sync"
- "time"
- )
-
- const (
- maxPlaintext = 16384 // maximum plaintext payload length
- maxCiphertext = 16384 + 2048 // maximum ciphertext payload length
- recordHeaderLen = 5 // record header length
- maxHandshake = 65536 // maximum handshake we support (protocol max is 16 MB)
-
- minVersion = 0x0301 // minimum supported version - TLS 1.0
- maxVersion = 0x0301 // maximum supported version - TLS 1.0
- )
-
- // TLS record types.
- type recordType uint8
-
- const (
- recordTypeChangeCipherSpec recordType = 20
- recordTypeAlert recordType = 21
- recordTypeHandshake recordType = 22
- recordTypeApplicationData recordType = 23
- )
-
- // TLS handshake message types.
- const (
- typeClientHello uint8 = 1
- typeServerHello uint8 = 2
- typeCertificate uint8 = 11
- typeServerKeyExchange uint8 = 12
- typeCertificateRequest uint8 = 13
- typeServerHelloDone uint8 = 14
- typeCertificateVerify uint8 = 15
- typeClientKeyExchange uint8 = 16
- typeFinished uint8 = 20
- typeCertificateStatus uint8 = 22
- typeNextProtocol uint8 = 67 // Not IANA assigned
- )
-
- // TLS compression types.
- const (
- compressionNone uint8 = 0
- )
-
- // TLS extension numbers
- var (
- extensionServerName uint16 = 0
- extensionStatusRequest uint16 = 5
- extensionSupportedCurves uint16 = 10
- extensionSupportedPoints uint16 = 11
- extensionNextProtoNeg uint16 = 13172 // not IANA assigned
- )
-
- // TLS Elliptic Curves
- // http://www.iana.org/assignments/tls-parameters/tls-parameters.xml#tls-parameters-8
- var (
- curveP256 uint16 = 23
- curveP384 uint16 = 24
- curveP521 uint16 = 25
- )
-
- // TLS Elliptic Curve Point Formats
- // http://www.iana.org/assignments/tls-parameters/tls-parameters.xml#tls-parameters-9
- var (
- pointFormatUncompressed uint8 = 0
- )
-
- // TLS CertificateStatusType (RFC 3546)
- const (
- statusTypeOCSP uint8 = 1
- )
-
- // Certificate types (for certificateRequestMsg)
- const (
- certTypeRSASign = 1 // A certificate containing an RSA key
- certTypeDSSSign = 2 // A certificate containing a DSA key
- certTypeRSAFixedDH = 3 // A certificate containing a static DH key
- certTypeDSSFixedDH = 4 // A certficiate containing a static DH key
- // Rest of these are reserved by the TLS spec
- )
-
- // ConnectionState records basic TLS details about the connection.
- type ConnectionState struct {
- HandshakeComplete bool
- CipherSuite uint16
- NegotiatedProtocol string
- NegotiatedProtocolIsMutual bool
-
- // the certificate chain that was presented by the other side
- PeerCertificates []*x509.Certificate
- }
-
- // 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.
- 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.
- Rand io.Reader
-
- // Time returns the current time as the number of seconds since the epoch.
- // If Time is nil, TLS uses the system time.Seconds.
- Time func() int64
-
- // Certificates contains one or more certificate chains
- // to present to the other side of the connection.
- // Server configurations must include at least one certificate.
- Certificates []Certificate
-
- // 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 *CASet
-
- // NextProtos is a list of supported, application level protocols.
- NextProtos []string
-
- // ServerName is included in the client's handshake to support virtual
- // hosting.
- ServerName string
-
- // AuthenticateClient controls whether a server will request a certificate
- // from the client. It does not require that the client send a
- // certificate nor does it require that the certificate sent be
- // anything more than self-signed.
- AuthenticateClient 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
- }
-
- func (c *Config) rand() io.Reader {
- r := c.Rand
- if r == nil {
- return rand.Reader
- }
- return r
- }
-
- func (c *Config) time() int64 {
- t := c.Time
- if t == nil {
- t = time.Seconds
- }
- return t()
- }
-
- func (c *Config) rootCAs() *CASet {
- s := c.RootCAs
- if s == nil {
- s = defaultRoots()
- }
- return s
- }
-
- func (c *Config) cipherSuites() []uint16 {
- s := c.CipherSuites
- if s == nil {
- s = defaultCipherSuites()
- }
- return s
- }
-
- // A Certificate is a chain of one or more certificates, leaf first.
- type Certificate struct {
- Certificate [][]byte
- PrivateKey *rsa.PrivateKey
- }
-
- // A TLS record.
- type record struct {
- contentType recordType
- major, minor uint8
- payload []byte
- }
-
- type handshakeMessage interface {
- marshal() []byte
- unmarshal([]byte) bool
- }
-
- // mutualVersion returns the protocol version to use given the advertised
- // version of the peer.
- func mutualVersion(vers uint16) (uint16, bool) {
- if vers < minVersion {
- return 0, false
- }
- if vers > maxVersion {
- vers = maxVersion
- }
- return vers, true
- }
-
- var emptyConfig Config
-
- func defaultConfig() *Config {
- return &emptyConfig
- }
-
- // Possible certificate files; stop after finding one.
- // On OS X we should really be using the Directory Services keychain
- // but that requires a lot of Mach goo to get at. Instead we use
- // the same root set that curl uses.
- var certFiles = []string{
- "/etc/ssl/certs/ca-certificates.crt", // Linux etc
- "/usr/share/curl/curl-ca-bundle.crt", // OS X
- }
-
- var once sync.Once
-
- func defaultRoots() *CASet {
- once.Do(initDefaults)
- return varDefaultRoots
- }
-
- func defaultCipherSuites() []uint16 {
- once.Do(initDefaults)
- return varDefaultCipherSuites
- }
-
- func initDefaults() {
- initDefaultRoots()
- initDefaultCipherSuites()
- }
-
- var varDefaultRoots *CASet
-
- func initDefaultRoots() {
- roots := NewCASet()
- for _, file := range certFiles {
- data, err := ioutil.ReadFile(file)
- if err == nil {
- roots.SetFromPEM(data)
- break
- }
- }
- varDefaultRoots = roots
- }
-
- var varDefaultCipherSuites []uint16
-
- func initDefaultCipherSuites() {
- varDefaultCipherSuites = make([]uint16, len(cipherSuites))
- i := 0
- for id, _ := range cipherSuites {
- varDefaultCipherSuites[i] = id
- i++
- }
- }
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