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path: root/src/pkg/crypto/tls/handshake_client.go
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Diffstat (limited to 'src/pkg/crypto/tls/handshake_client.go')
-rw-r--r--src/pkg/crypto/tls/handshake_client.go362
1 files changed, 276 insertions, 86 deletions
diff --git a/src/pkg/crypto/tls/handshake_client.go b/src/pkg/crypto/tls/handshake_client.go
index 85e4adefc..a320fde1b 100644
--- a/src/pkg/crypto/tls/handshake_client.go
+++ b/src/pkg/crypto/tls/handshake_client.go
@@ -12,24 +12,41 @@ import (
"crypto/x509"
"encoding/asn1"
"errors"
+ "fmt"
"io"
+ "net"
"strconv"
)
+type clientHandshakeState struct {
+ c *Conn
+ serverHello *serverHelloMsg
+ hello *clientHelloMsg
+ suite *cipherSuite
+ finishedHash finishedHash
+ masterSecret []byte
+ session *ClientSessionState
+}
+
func (c *Conn) clientHandshake() error {
if c.config == nil {
c.config = defaultConfig()
}
+ if len(c.config.ServerName) == 0 && !c.config.InsecureSkipVerify {
+ return errors.New("tls: either ServerName or InsecureSkipVerify must be specified in the tls.Config")
+ }
+
hello := &clientHelloMsg{
- vers: c.config.maxVersion(),
- compressionMethods: []uint8{compressionNone},
- random: make([]byte, 32),
- ocspStapling: true,
- serverName: c.config.ServerName,
- supportedCurves: []uint16{curveP256, curveP384, curveP521},
- supportedPoints: []uint8{pointFormatUncompressed},
- nextProtoNeg: len(c.config.NextProtos) > 0,
+ vers: c.config.maxVersion(),
+ compressionMethods: []uint8{compressionNone},
+ random: make([]byte, 32),
+ ocspStapling: true,
+ serverName: c.config.ServerName,
+ supportedCurves: c.config.curvePreferences(),
+ supportedPoints: []uint8{pointFormatUncompressed},
+ nextProtoNeg: len(c.config.NextProtos) > 0,
+ secureRenegotiation: true,
}
possibleCipherSuites := c.config.cipherSuites()
@@ -51,21 +68,61 @@ NextCipherSuite:
}
}
- t := uint32(c.config.time().Unix())
- hello.random[0] = byte(t >> 24)
- hello.random[1] = byte(t >> 16)
- hello.random[2] = byte(t >> 8)
- hello.random[3] = byte(t)
- _, err := io.ReadFull(c.config.rand(), hello.random[4:])
+ _, err := io.ReadFull(c.config.rand(), hello.random)
if err != nil {
c.sendAlert(alertInternalError)
- return errors.New("short read from Rand")
+ return errors.New("tls: short read from Rand: " + err.Error())
}
if hello.vers >= VersionTLS12 {
hello.signatureAndHashes = supportedSKXSignatureAlgorithms
}
+ var session *ClientSessionState
+ var cacheKey string
+ sessionCache := c.config.ClientSessionCache
+ if c.config.SessionTicketsDisabled {
+ sessionCache = nil
+ }
+
+ if sessionCache != nil {
+ hello.ticketSupported = true
+
+ // Try to resume a previously negotiated TLS session, if
+ // available.
+ cacheKey = clientSessionCacheKey(c.conn.RemoteAddr(), c.config)
+ candidateSession, ok := sessionCache.Get(cacheKey)
+ if ok {
+ // Check that the ciphersuite/version used for the
+ // previous session are still valid.
+ cipherSuiteOk := false
+ for _, id := range hello.cipherSuites {
+ if id == candidateSession.cipherSuite {
+ cipherSuiteOk = true
+ break
+ }
+ }
+
+ versOk := candidateSession.vers >= c.config.minVersion() &&
+ candidateSession.vers <= c.config.maxVersion()
+ if versOk && cipherSuiteOk {
+ session = candidateSession
+ }
+ }
+ }
+
+ if session != nil {
+ hello.sessionTicket = session.sessionTicket
+ // A random session ID is used to detect when the
+ // server accepted the ticket and is resuming a session
+ // (see RFC 5077).
+ hello.sessionId = make([]byte, 16)
+ if _, err := io.ReadFull(c.config.rand(), hello.sessionId); err != nil {
+ c.sendAlert(alertInternalError)
+ return errors.New("tls: short read from Rand: " + err.Error())
+ }
+ }
+
c.writeRecord(recordTypeHandshake, hello.marshal())
msg, err := c.readHandshake()
@@ -74,51 +131,103 @@ NextCipherSuite:
}
serverHello, ok := msg.(*serverHelloMsg)
if !ok {
- return c.sendAlert(alertUnexpectedMessage)
+ c.sendAlert(alertUnexpectedMessage)
+ return unexpectedMessageError(serverHello, msg)
}
vers, ok := c.config.mutualVersion(serverHello.vers)
if !ok || vers < VersionTLS10 {
// TLS 1.0 is the minimum version supported as a client.
- return c.sendAlert(alertProtocolVersion)
+ c.sendAlert(alertProtocolVersion)
+ return fmt.Errorf("tls: server selected unsupported protocol version %x", serverHello.vers)
}
c.vers = vers
c.haveVers = true
- finishedHash := newFinishedHash(c.vers)
- finishedHash.Write(hello.marshal())
- finishedHash.Write(serverHello.marshal())
+ suite := mutualCipherSuite(c.config.cipherSuites(), serverHello.cipherSuite)
+ if suite == nil {
+ c.sendAlert(alertHandshakeFailure)
+ return fmt.Errorf("tls: server selected an unsupported cipher suite")
+ }
- if serverHello.compressionMethod != compressionNone {
- return c.sendAlert(alertUnexpectedMessage)
+ hs := &clientHandshakeState{
+ c: c,
+ serverHello: serverHello,
+ hello: hello,
+ suite: suite,
+ finishedHash: newFinishedHash(c.vers),
+ session: session,
}
- if !hello.nextProtoNeg && serverHello.nextProtoNeg {
- c.sendAlert(alertHandshakeFailure)
- return errors.New("server advertised unrequested NPN")
+ hs.finishedHash.Write(hs.hello.marshal())
+ hs.finishedHash.Write(hs.serverHello.marshal())
+
+ isResume, err := hs.processServerHello()
+ if err != nil {
+ return err
}
- suite := mutualCipherSuite(c.config.cipherSuites(), serverHello.cipherSuite)
- if suite == nil {
- return c.sendAlert(alertHandshakeFailure)
+ if isResume {
+ if err := hs.establishKeys(); err != nil {
+ return err
+ }
+ if err := hs.readSessionTicket(); err != nil {
+ return err
+ }
+ if err := hs.readFinished(); err != nil {
+ return err
+ }
+ if err := hs.sendFinished(); err != nil {
+ return err
+ }
+ } else {
+ if err := hs.doFullHandshake(); err != nil {
+ return err
+ }
+ if err := hs.establishKeys(); err != nil {
+ return err
+ }
+ if err := hs.sendFinished(); err != nil {
+ return err
+ }
+ if err := hs.readSessionTicket(); err != nil {
+ return err
+ }
+ if err := hs.readFinished(); err != nil {
+ return err
+ }
}
- msg, err = c.readHandshake()
+ if sessionCache != nil && hs.session != nil && session != hs.session {
+ sessionCache.Put(cacheKey, hs.session)
+ }
+
+ c.didResume = isResume
+ c.handshakeComplete = true
+ c.cipherSuite = suite.id
+ return nil
+}
+
+func (hs *clientHandshakeState) doFullHandshake() error {
+ c := hs.c
+
+ msg, err := c.readHandshake()
if err != nil {
return err
}
certMsg, ok := msg.(*certificateMsg)
if !ok || len(certMsg.certificates) == 0 {
- return c.sendAlert(alertUnexpectedMessage)
+ c.sendAlert(alertUnexpectedMessage)
+ return unexpectedMessageError(certMsg, msg)
}
- finishedHash.Write(certMsg.marshal())
+ hs.finishedHash.Write(certMsg.marshal())
certs := make([]*x509.Certificate, len(certMsg.certificates))
for i, asn1Data := range certMsg.certificates {
cert, err := x509.ParseCertificate(asn1Data)
if err != nil {
c.sendAlert(alertBadCertificate)
- return errors.New("failed to parse certificate from server: " + err.Error())
+ return errors.New("tls: failed to parse certificate from server: " + err.Error())
}
certs[i] = cert
}
@@ -148,21 +257,23 @@ NextCipherSuite:
case *rsa.PublicKey, *ecdsa.PublicKey:
break
default:
- return c.sendAlert(alertUnsupportedCertificate)
+ c.sendAlert(alertUnsupportedCertificate)
+ return fmt.Errorf("tls: server's certificate contains an unsupported type of public key: %T", certs[0].PublicKey)
}
c.peerCertificates = certs
- if serverHello.ocspStapling {
+ if hs.serverHello.ocspStapling {
msg, err = c.readHandshake()
if err != nil {
return err
}
cs, ok := msg.(*certificateStatusMsg)
if !ok {
- return c.sendAlert(alertUnexpectedMessage)
+ c.sendAlert(alertUnexpectedMessage)
+ return unexpectedMessageError(cs, msg)
}
- finishedHash.Write(cs.marshal())
+ hs.finishedHash.Write(cs.marshal())
if cs.statusType == statusTypeOCSP {
c.ocspResponse = cs.response
@@ -174,12 +285,12 @@ NextCipherSuite:
return err
}
- keyAgreement := suite.ka(c.vers)
+ keyAgreement := hs.suite.ka(c.vers)
skx, ok := msg.(*serverKeyExchangeMsg)
if ok {
- finishedHash.Write(skx.marshal())
- err = keyAgreement.processServerKeyExchange(c.config, hello, serverHello, certs[0], skx)
+ hs.finishedHash.Write(skx.marshal())
+ err = keyAgreement.processServerKeyExchange(c.config, hs.hello, hs.serverHello, certs[0], skx)
if err != nil {
c.sendAlert(alertUnexpectedMessage)
return err
@@ -208,7 +319,7 @@ NextCipherSuite:
// ClientCertificateType, unless there is some external
// arrangement to the contrary.
- finishedHash.Write(certReq.marshal())
+ hs.finishedHash.Write(certReq.marshal())
var rsaAvail, ecdsaAvail bool
for _, certType := range certReq.certificateTypes {
@@ -271,9 +382,10 @@ NextCipherSuite:
shd, ok := msg.(*serverHelloDoneMsg)
if !ok {
- return c.sendAlert(alertUnexpectedMessage)
+ c.sendAlert(alertUnexpectedMessage)
+ return unexpectedMessageError(shd, msg)
}
- finishedHash.Write(shd.marshal())
+ hs.finishedHash.Write(shd.marshal())
// If the server requested a certificate then we have to send a
// Certificate message, even if it's empty because we don't have a
@@ -283,17 +395,17 @@ NextCipherSuite:
if chainToSend != nil {
certMsg.certificates = chainToSend.Certificate
}
- finishedHash.Write(certMsg.marshal())
+ hs.finishedHash.Write(certMsg.marshal())
c.writeRecord(recordTypeHandshake, certMsg.marshal())
}
- preMasterSecret, ckx, err := keyAgreement.generateClientKeyExchange(c.config, hello, certs[0])
+ preMasterSecret, ckx, err := keyAgreement.generateClientKeyExchange(c.config, hs.hello, certs[0])
if err != nil {
c.sendAlert(alertInternalError)
return err
}
if ckx != nil {
- finishedHash.Write(ckx.marshal())
+ hs.finishedHash.Write(ckx.marshal())
c.writeRecord(recordTypeHandshake, ckx.marshal())
}
@@ -305,7 +417,7 @@ NextCipherSuite:
switch key := c.config.Certificates[0].PrivateKey.(type) {
case *ecdsa.PrivateKey:
- digest, _, hashId := finishedHash.hashForClientCertificate(signatureECDSA)
+ digest, _, hashId := hs.finishedHash.hashForClientCertificate(signatureECDSA)
r, s, err := ecdsa.Sign(c.config.rand(), key, digest)
if err == nil {
signed, err = asn1.Marshal(ecdsaSignature{r, s})
@@ -313,7 +425,7 @@ NextCipherSuite:
certVerify.signatureAndHash.signature = signatureECDSA
certVerify.signatureAndHash.hash = hashId
case *rsa.PrivateKey:
- digest, hashFunc, hashId := finishedHash.hashForClientCertificate(signatureRSA)
+ digest, hashFunc, hashId := hs.finishedHash.hashForClientCertificate(signatureRSA)
signed, err = rsa.SignPKCS1v15(c.config.rand(), key, hashFunc, digest)
certVerify.signatureAndHash.signature = signatureRSA
certVerify.signatureAndHash.hash = hashId
@@ -321,79 +433,157 @@ NextCipherSuite:
err = errors.New("unknown private key type")
}
if err != nil {
- return c.sendAlert(alertInternalError)
+ c.sendAlert(alertInternalError)
+ return errors.New("tls: failed to sign handshake with client certificate: " + err.Error())
}
certVerify.signature = signed
- finishedHash.Write(certVerify.marshal())
+ hs.finishedHash.Write(certVerify.marshal())
c.writeRecord(recordTypeHandshake, certVerify.marshal())
}
- masterSecret := masterFromPreMasterSecret(c.vers, preMasterSecret, hello.random, serverHello.random)
- clientMAC, serverMAC, clientKey, serverKey, clientIV, serverIV :=
- keysFromMasterSecret(c.vers, masterSecret, hello.random, serverHello.random, suite.macLen, suite.keyLen, suite.ivLen)
+ hs.masterSecret = masterFromPreMasterSecret(c.vers, preMasterSecret, hs.hello.random, hs.serverHello.random)
+ return nil
+}
+
+func (hs *clientHandshakeState) establishKeys() error {
+ c := hs.c
- var clientCipher interface{}
- var clientHash macFunction
- if suite.cipher != nil {
- clientCipher = suite.cipher(clientKey, clientIV, false /* not for reading */)
- clientHash = suite.mac(c.vers, clientMAC)
+ clientMAC, serverMAC, clientKey, serverKey, clientIV, serverIV :=
+ keysFromMasterSecret(c.vers, hs.masterSecret, hs.hello.random, hs.serverHello.random, hs.suite.macLen, hs.suite.keyLen, hs.suite.ivLen)
+ var clientCipher, serverCipher interface{}
+ var clientHash, serverHash macFunction
+ if hs.suite.cipher != nil {
+ clientCipher = hs.suite.cipher(clientKey, clientIV, false /* not for reading */)
+ clientHash = hs.suite.mac(c.vers, clientMAC)
+ serverCipher = hs.suite.cipher(serverKey, serverIV, true /* for reading */)
+ serverHash = hs.suite.mac(c.vers, serverMAC)
} else {
- clientCipher = suite.aead(clientKey, clientIV)
+ clientCipher = hs.suite.aead(clientKey, clientIV)
+ serverCipher = hs.suite.aead(serverKey, serverIV)
}
+
+ c.in.prepareCipherSpec(c.vers, serverCipher, serverHash)
c.out.prepareCipherSpec(c.vers, clientCipher, clientHash)
- c.writeRecord(recordTypeChangeCipherSpec, []byte{1})
+ return nil
+}
- if serverHello.nextProtoNeg {
- nextProto := new(nextProtoMsg)
- proto, fallback := mutualProtocol(c.config.NextProtos, serverHello.nextProtos)
- nextProto.proto = proto
- c.clientProtocol = proto
- c.clientProtocolFallback = fallback
+func (hs *clientHandshakeState) serverResumedSession() bool {
+ // If the server responded with the same sessionId then it means the
+ // sessionTicket is being used to resume a TLS session.
+ return hs.session != nil && hs.hello.sessionId != nil &&
+ bytes.Equal(hs.serverHello.sessionId, hs.hello.sessionId)
+}
- finishedHash.Write(nextProto.marshal())
- c.writeRecord(recordTypeHandshake, nextProto.marshal())
+func (hs *clientHandshakeState) processServerHello() (bool, error) {
+ c := hs.c
+
+ if hs.serverHello.compressionMethod != compressionNone {
+ c.sendAlert(alertUnexpectedMessage)
+ return false, errors.New("tls: server selected unsupported compression format")
}
- finished := new(finishedMsg)
- finished.verifyData = finishedHash.clientSum(masterSecret)
- finishedHash.Write(finished.marshal())
- c.writeRecord(recordTypeHandshake, finished.marshal())
+ if !hs.hello.nextProtoNeg && hs.serverHello.nextProtoNeg {
+ c.sendAlert(alertHandshakeFailure)
+ return false, errors.New("server advertised unrequested NPN extension")
+ }
- var serverCipher interface{}
- var serverHash macFunction
- if suite.cipher != nil {
- serverCipher = suite.cipher(serverKey, serverIV, true /* for reading */)
- serverHash = suite.mac(c.vers, serverMAC)
- } else {
- serverCipher = suite.aead(serverKey, serverIV)
+ if hs.serverResumedSession() {
+ // Restore masterSecret and peerCerts from previous state
+ hs.masterSecret = hs.session.masterSecret
+ c.peerCertificates = hs.session.serverCertificates
+ return true, nil
}
- c.in.prepareCipherSpec(c.vers, serverCipher, serverHash)
+ return false, nil
+}
+
+func (hs *clientHandshakeState) readFinished() error {
+ c := hs.c
+
c.readRecord(recordTypeChangeCipherSpec)
- if err := c.error(); err != nil {
+ if err := c.in.error(); err != nil {
return err
}
- msg, err = c.readHandshake()
+ msg, err := c.readHandshake()
if err != nil {
return err
}
serverFinished, ok := msg.(*finishedMsg)
if !ok {
- return c.sendAlert(alertUnexpectedMessage)
+ c.sendAlert(alertUnexpectedMessage)
+ return unexpectedMessageError(serverFinished, msg)
}
- verify := finishedHash.serverSum(masterSecret)
+ verify := hs.finishedHash.serverSum(hs.masterSecret)
if len(verify) != len(serverFinished.verifyData) ||
subtle.ConstantTimeCompare(verify, serverFinished.verifyData) != 1 {
- return c.sendAlert(alertHandshakeFailure)
+ c.sendAlert(alertHandshakeFailure)
+ return errors.New("tls: server's Finished message was incorrect")
+ }
+ hs.finishedHash.Write(serverFinished.marshal())
+ return nil
+}
+
+func (hs *clientHandshakeState) readSessionTicket() error {
+ if !hs.serverHello.ticketSupported {
+ return nil
+ }
+
+ c := hs.c
+ msg, err := c.readHandshake()
+ if err != nil {
+ return err
+ }
+ sessionTicketMsg, ok := msg.(*newSessionTicketMsg)
+ if !ok {
+ c.sendAlert(alertUnexpectedMessage)
+ return unexpectedMessageError(sessionTicketMsg, msg)
+ }
+ hs.finishedHash.Write(sessionTicketMsg.marshal())
+
+ hs.session = &ClientSessionState{
+ sessionTicket: sessionTicketMsg.ticket,
+ vers: c.vers,
+ cipherSuite: hs.suite.id,
+ masterSecret: hs.masterSecret,
+ serverCertificates: c.peerCertificates,
}
- c.handshakeComplete = true
- c.cipherSuite = suite.id
return nil
}
+func (hs *clientHandshakeState) sendFinished() error {
+ c := hs.c
+
+ c.writeRecord(recordTypeChangeCipherSpec, []byte{1})
+ if hs.serverHello.nextProtoNeg {
+ nextProto := new(nextProtoMsg)
+ proto, fallback := mutualProtocol(c.config.NextProtos, hs.serverHello.nextProtos)
+ nextProto.proto = proto
+ c.clientProtocol = proto
+ c.clientProtocolFallback = fallback
+
+ hs.finishedHash.Write(nextProto.marshal())
+ c.writeRecord(recordTypeHandshake, nextProto.marshal())
+ }
+
+ finished := new(finishedMsg)
+ finished.verifyData = hs.finishedHash.clientSum(hs.masterSecret)
+ hs.finishedHash.Write(finished.marshal())
+ c.writeRecord(recordTypeHandshake, finished.marshal())
+ return nil
+}
+
+// clientSessionCacheKey returns a key used to cache sessionTickets that could
+// be used to resume previously negotiated TLS sessions with a server.
+func clientSessionCacheKey(serverAddr net.Addr, config *Config) string {
+ if len(config.ServerName) > 0 {
+ return config.ServerName
+ }
+ return serverAddr.String()
+}
+
// mutualProtocol finds the mutual Next Protocol Negotiation protocol given the
// set of client and server supported protocols. The set of client supported
// protocols must not be empty. It returns the resulting protocol and flag
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-21 14:21:46 +0000