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path: root/src/pkg/crypto/tls/conn.go
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Diffstat (limited to 'src/pkg/crypto/tls/conn.go')
-rw-r--r--src/pkg/crypto/tls/conn.go1030
1 files changed, 0 insertions, 1030 deletions
diff --git a/src/pkg/crypto/tls/conn.go b/src/pkg/crypto/tls/conn.go
deleted file mode 100644
index ba8e4c22b..000000000
--- a/src/pkg/crypto/tls/conn.go
+++ /dev/null
@@ -1,1030 +0,0 @@
-// Copyright 2010 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.
-
-// TLS low level connection and record layer
-
-package tls
-
-import (
- "bytes"
- "crypto/cipher"
- "crypto/subtle"
- "crypto/x509"
- "errors"
- "fmt"
- "io"
- "net"
- "sync"
- "time"
-)
-
-// A Conn represents a secured connection.
-// It implements the net.Conn interface.
-type Conn struct {
- // constant
- conn net.Conn
- isClient bool
-
- // constant after handshake; protected by handshakeMutex
- handshakeMutex sync.Mutex // handshakeMutex < in.Mutex, out.Mutex, errMutex
- handshakeErr error // error resulting from handshake
- vers uint16 // TLS version
- haveVers bool // version has been negotiated
- config *Config // configuration passed to constructor
- handshakeComplete bool
- didResume bool // whether this connection was a session resumption
- cipherSuite uint16
- ocspResponse []byte // stapled OCSP response
- peerCertificates []*x509.Certificate
- // verifiedChains contains the certificate chains that we built, as
- // opposed to the ones presented by the server.
- verifiedChains [][]*x509.Certificate
- // serverName contains the server name indicated by the client, if any.
- serverName string
- // firstFinished contains the first Finished hash sent during the
- // handshake. This is the "tls-unique" channel binding value.
- firstFinished [12]byte
-
- clientProtocol string
- clientProtocolFallback bool
-
- // input/output
- in, out halfConn // in.Mutex < out.Mutex
- rawInput *block // raw input, right off the wire
- input *block // application data waiting to be read
- hand bytes.Buffer // handshake data waiting to be read
-
- tmp [16]byte
-}
-
-// Access to net.Conn methods.
-// Cannot just embed net.Conn because that would
-// export the struct field too.
-
-// LocalAddr returns the local network address.
-func (c *Conn) LocalAddr() net.Addr {
- return c.conn.LocalAddr()
-}
-
-// RemoteAddr returns the remote network address.
-func (c *Conn) RemoteAddr() net.Addr {
- return c.conn.RemoteAddr()
-}
-
-// 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 (c *Conn) SetDeadline(t time.Time) error {
- return c.conn.SetDeadline(t)
-}
-
-// SetReadDeadline sets the read deadline on the underlying connection.
-// A zero value for t means Read will not time out.
-func (c *Conn) SetReadDeadline(t time.Time) error {
- return c.conn.SetReadDeadline(t)
-}
-
-// 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 (c *Conn) SetWriteDeadline(t time.Time) error {
- return c.conn.SetWriteDeadline(t)
-}
-
-// A halfConn represents one direction of the record layer
-// connection, either sending or receiving.
-type halfConn struct {
- sync.Mutex
-
- err error // first permanent error
- version uint16 // protocol version
- cipher interface{} // cipher algorithm
- mac macFunction
- seq [8]byte // 64-bit sequence number
- bfree *block // list of free blocks
-
- nextCipher interface{} // next encryption state
- nextMac macFunction // next MAC algorithm
-
- // used to save allocating a new buffer for each MAC.
- inDigestBuf, outDigestBuf []byte
-}
-
-func (hc *halfConn) setErrorLocked(err error) error {
- hc.err = err
- return err
-}
-
-func (hc *halfConn) error() error {
- hc.Lock()
- err := hc.err
- hc.Unlock()
- return err
-}
-
-// prepareCipherSpec sets the encryption and MAC states
-// that a subsequent changeCipherSpec will use.
-func (hc *halfConn) prepareCipherSpec(version uint16, cipher interface{}, mac macFunction) {
- hc.version = version
- hc.nextCipher = cipher
- hc.nextMac = mac
-}
-
-// changeCipherSpec changes the encryption and MAC states
-// to the ones previously passed to prepareCipherSpec.
-func (hc *halfConn) changeCipherSpec() error {
- if hc.nextCipher == nil {
- return alertInternalError
- }
- hc.cipher = hc.nextCipher
- hc.mac = hc.nextMac
- hc.nextCipher = nil
- hc.nextMac = nil
- for i := range hc.seq {
- hc.seq[i] = 0
- }
- return nil
-}
-
-// incSeq increments the sequence number.
-func (hc *halfConn) incSeq() {
- for i := 7; i >= 0; i-- {
- hc.seq[i]++
- if hc.seq[i] != 0 {
- return
- }
- }
-
- // Not allowed to let sequence number wrap.
- // Instead, must renegotiate before it does.
- // Not likely enough to bother.
- panic("TLS: sequence number wraparound")
-}
-
-// resetSeq resets the sequence number to zero.
-func (hc *halfConn) resetSeq() {
- for i := range hc.seq {
- hc.seq[i] = 0
- }
-}
-
-// removePadding returns an unpadded slice, in constant time, which is a prefix
-// of the input. It also returns a byte which is equal to 255 if the padding
-// was valid and 0 otherwise. See RFC 2246, section 6.2.3.2
-func removePadding(payload []byte) ([]byte, byte) {
- if len(payload) < 1 {
- return payload, 0
- }
-
- paddingLen := payload[len(payload)-1]
- t := uint(len(payload)-1) - uint(paddingLen)
- // if len(payload) >= (paddingLen - 1) then the MSB of t is zero
- good := byte(int32(^t) >> 31)
-
- toCheck := 255 // the maximum possible padding length
- // The length of the padded data is public, so we can use an if here
- if toCheck+1 > len(payload) {
- toCheck = len(payload) - 1
- }
-
- for i := 0; i < toCheck; i++ {
- t := uint(paddingLen) - uint(i)
- // if i <= paddingLen then the MSB of t is zero
- mask := byte(int32(^t) >> 31)
- b := payload[len(payload)-1-i]
- good &^= mask&paddingLen ^ mask&b
- }
-
- // We AND together the bits of good and replicate the result across
- // all the bits.
- good &= good << 4
- good &= good << 2
- good &= good << 1
- good = uint8(int8(good) >> 7)
-
- toRemove := good&paddingLen + 1
- return payload[:len(payload)-int(toRemove)], good
-}
-
-// removePaddingSSL30 is a replacement for removePadding in the case that the
-// protocol version is SSLv3. In this version, the contents of the padding
-// are random and cannot be checked.
-func removePaddingSSL30(payload []byte) ([]byte, byte) {
- if len(payload) < 1 {
- return payload, 0
- }
-
- paddingLen := int(payload[len(payload)-1]) + 1
- if paddingLen > len(payload) {
- return payload, 0
- }
-
- return payload[:len(payload)-paddingLen], 255
-}
-
-func roundUp(a, b int) int {
- return a + (b-a%b)%b
-}
-
-// cbcMode is an interface for block ciphers using cipher block chaining.
-type cbcMode interface {
- cipher.BlockMode
- SetIV([]byte)
-}
-
-// decrypt checks and strips the mac and decrypts the data in b. Returns a
-// success boolean, the number of bytes to skip from the start of the record in
-// order to get the application payload, and an optional alert value.
-func (hc *halfConn) decrypt(b *block) (ok bool, prefixLen int, alertValue alert) {
- // pull out payload
- payload := b.data[recordHeaderLen:]
-
- macSize := 0
- if hc.mac != nil {
- macSize = hc.mac.Size()
- }
-
- paddingGood := byte(255)
- explicitIVLen := 0
-
- // decrypt
- if hc.cipher != nil {
- switch c := hc.cipher.(type) {
- case cipher.Stream:
- c.XORKeyStream(payload, payload)
- case cipher.AEAD:
- explicitIVLen = 8
- if len(payload) < explicitIVLen {
- return false, 0, alertBadRecordMAC
- }
- nonce := payload[:8]
- payload = payload[8:]
-
- var additionalData [13]byte
- copy(additionalData[:], hc.seq[:])
- copy(additionalData[8:], b.data[:3])
- n := len(payload) - c.Overhead()
- additionalData[11] = byte(n >> 8)
- additionalData[12] = byte(n)
- var err error
- payload, err = c.Open(payload[:0], nonce, payload, additionalData[:])
- if err != nil {
- return false, 0, alertBadRecordMAC
- }
- b.resize(recordHeaderLen + explicitIVLen + len(payload))
- case cbcMode:
- blockSize := c.BlockSize()
- if hc.version >= VersionTLS11 {
- explicitIVLen = blockSize
- }
-
- if len(payload)%blockSize != 0 || len(payload) < roundUp(explicitIVLen+macSize+1, blockSize) {
- return false, 0, alertBadRecordMAC
- }
-
- if explicitIVLen > 0 {
- c.SetIV(payload[:explicitIVLen])
- payload = payload[explicitIVLen:]
- }
- c.CryptBlocks(payload, payload)
- if hc.version == VersionSSL30 {
- payload, paddingGood = removePaddingSSL30(payload)
- } else {
- payload, paddingGood = removePadding(payload)
- }
- b.resize(recordHeaderLen + explicitIVLen + len(payload))
-
- // note that we still have a timing side-channel in the
- // MAC check, below. An attacker can align the record
- // so that a correct padding will cause one less hash
- // block to be calculated. Then they can iteratively
- // decrypt a record by breaking each byte. See
- // "Password Interception in a SSL/TLS Channel", Brice
- // Canvel et al.
- //
- // However, our behavior matches OpenSSL, so we leak
- // only as much as they do.
- default:
- panic("unknown cipher type")
- }
- }
-
- // check, strip mac
- if hc.mac != nil {
- if len(payload) < macSize {
- return false, 0, alertBadRecordMAC
- }
-
- // strip mac off payload, b.data
- n := len(payload) - macSize
- b.data[3] = byte(n >> 8)
- b.data[4] = byte(n)
- b.resize(recordHeaderLen + explicitIVLen + n)
- remoteMAC := payload[n:]
- localMAC := hc.mac.MAC(hc.inDigestBuf, hc.seq[0:], b.data[:recordHeaderLen], payload[:n])
-
- if subtle.ConstantTimeCompare(localMAC, remoteMAC) != 1 || paddingGood != 255 {
- return false, 0, alertBadRecordMAC
- }
- hc.inDigestBuf = localMAC
- }
- hc.incSeq()
-
- return true, recordHeaderLen + explicitIVLen, 0
-}
-
-// padToBlockSize calculates the needed padding block, if any, for a payload.
-// On exit, prefix aliases payload and extends to the end of the last full
-// block of payload. finalBlock is a fresh slice which contains the contents of
-// any suffix of payload as well as the needed padding to make finalBlock a
-// full block.
-func padToBlockSize(payload []byte, blockSize int) (prefix, finalBlock []byte) {
- overrun := len(payload) % blockSize
- paddingLen := blockSize - overrun
- prefix = payload[:len(payload)-overrun]
- finalBlock = make([]byte, blockSize)
- copy(finalBlock, payload[len(payload)-overrun:])
- for i := overrun; i < blockSize; i++ {
- finalBlock[i] = byte(paddingLen - 1)
- }
- return
-}
-
-// encrypt encrypts and macs the data in b.
-func (hc *halfConn) encrypt(b *block, explicitIVLen int) (bool, alert) {
- // mac
- if hc.mac != nil {
- mac := hc.mac.MAC(hc.outDigestBuf, hc.seq[0:], b.data[:recordHeaderLen], b.data[recordHeaderLen+explicitIVLen:])
-
- n := len(b.data)
- b.resize(n + len(mac))
- copy(b.data[n:], mac)
- hc.outDigestBuf = mac
- }
-
- payload := b.data[recordHeaderLen:]
-
- // encrypt
- if hc.cipher != nil {
- switch c := hc.cipher.(type) {
- case cipher.Stream:
- c.XORKeyStream(payload, payload)
- case cipher.AEAD:
- payloadLen := len(b.data) - recordHeaderLen - explicitIVLen
- b.resize(len(b.data) + c.Overhead())
- nonce := b.data[recordHeaderLen : recordHeaderLen+explicitIVLen]
- payload := b.data[recordHeaderLen+explicitIVLen:]
- payload = payload[:payloadLen]
-
- var additionalData [13]byte
- copy(additionalData[:], hc.seq[:])
- copy(additionalData[8:], b.data[:3])
- additionalData[11] = byte(payloadLen >> 8)
- additionalData[12] = byte(payloadLen)
-
- c.Seal(payload[:0], nonce, payload, additionalData[:])
- case cbcMode:
- blockSize := c.BlockSize()
- if explicitIVLen > 0 {
- c.SetIV(payload[:explicitIVLen])
- payload = payload[explicitIVLen:]
- }
- prefix, finalBlock := padToBlockSize(payload, blockSize)
- b.resize(recordHeaderLen + explicitIVLen + len(prefix) + len(finalBlock))
- c.CryptBlocks(b.data[recordHeaderLen+explicitIVLen:], prefix)
- c.CryptBlocks(b.data[recordHeaderLen+explicitIVLen+len(prefix):], finalBlock)
- default:
- panic("unknown cipher type")
- }
- }
-
- // update length to include MAC and any block padding needed.
- n := len(b.data) - recordHeaderLen
- b.data[3] = byte(n >> 8)
- b.data[4] = byte(n)
- hc.incSeq()
-
- return true, 0
-}
-
-// A block is a simple data buffer.
-type block struct {
- data []byte
- off int // index for Read
- link *block
-}
-
-// resize resizes block to be n bytes, growing if necessary.
-func (b *block) resize(n int) {
- if n > cap(b.data) {
- b.reserve(n)
- }
- b.data = b.data[0:n]
-}
-
-// reserve makes sure that block contains a capacity of at least n bytes.
-func (b *block) reserve(n int) {
- if cap(b.data) >= n {
- return
- }
- m := cap(b.data)
- if m == 0 {
- m = 1024
- }
- for m < n {
- m *= 2
- }
- data := make([]byte, len(b.data), m)
- copy(data, b.data)
- b.data = data
-}
-
-// readFromUntil reads from r into b until b contains at least n bytes
-// or else returns an error.
-func (b *block) readFromUntil(r io.Reader, n int) error {
- // quick case
- if len(b.data) >= n {
- return nil
- }
-
- // read until have enough.
- b.reserve(n)
- for {
- m, err := r.Read(b.data[len(b.data):cap(b.data)])
- b.data = b.data[0 : len(b.data)+m]
- if len(b.data) >= n {
- // TODO(bradfitz,agl): slightly suspicious
- // that we're throwing away r.Read's err here.
- break
- }
- if err != nil {
- return err
- }
- }
- return nil
-}
-
-func (b *block) Read(p []byte) (n int, err error) {
- n = copy(p, b.data[b.off:])
- b.off += n
- return
-}
-
-// newBlock allocates a new block, from hc's free list if possible.
-func (hc *halfConn) newBlock() *block {
- b := hc.bfree
- if b == nil {
- return new(block)
- }
- hc.bfree = b.link
- b.link = nil
- b.resize(0)
- return b
-}
-
-// freeBlock returns a block to hc's free list.
-// The protocol is such that each side only has a block or two on
-// its free list at a time, so there's no need to worry about
-// trimming the list, etc.
-func (hc *halfConn) freeBlock(b *block) {
- b.link = hc.bfree
- hc.bfree = b
-}
-
-// splitBlock splits a block after the first n bytes,
-// returning a block with those n bytes and a
-// block with the remainder. the latter may be nil.
-func (hc *halfConn) splitBlock(b *block, n int) (*block, *block) {
- if len(b.data) <= n {
- return b, nil
- }
- bb := hc.newBlock()
- bb.resize(len(b.data) - n)
- copy(bb.data, b.data[n:])
- b.data = b.data[0:n]
- return b, bb
-}
-
-// readRecord reads the next TLS record from the connection
-// and updates the record layer state.
-// c.in.Mutex <= L; c.input == nil.
-func (c *Conn) readRecord(want recordType) error {
- // Caller must be in sync with connection:
- // handshake data if handshake not yet completed,
- // else application data. (We don't support renegotiation.)
- switch want {
- default:
- c.sendAlert(alertInternalError)
- return c.in.setErrorLocked(errors.New("tls: unknown record type requested"))
- case recordTypeHandshake, recordTypeChangeCipherSpec:
- if c.handshakeComplete {
- c.sendAlert(alertInternalError)
- return c.in.setErrorLocked(errors.New("tls: handshake or ChangeCipherSpec requested after handshake complete"))
- }
- case recordTypeApplicationData:
- if !c.handshakeComplete {
- c.sendAlert(alertInternalError)
- return c.in.setErrorLocked(errors.New("tls: application data record requested before handshake complete"))
- }
- }
-
-Again:
- if c.rawInput == nil {
- c.rawInput = c.in.newBlock()
- }
- b := c.rawInput
-
- // Read header, payload.
- if err := b.readFromUntil(c.conn, recordHeaderLen); err != nil {
- // RFC suggests that EOF without an alertCloseNotify is
- // an error, but popular web sites seem to do this,
- // so we can't make it an error.
- // if err == io.EOF {
- // err = io.ErrUnexpectedEOF
- // }
- if e, ok := err.(net.Error); !ok || !e.Temporary() {
- c.in.setErrorLocked(err)
- }
- return err
- }
- typ := recordType(b.data[0])
-
- // No valid TLS record has a type of 0x80, however SSLv2 handshakes
- // start with a uint16 length where the MSB is set and the first record
- // is always < 256 bytes long. Therefore typ == 0x80 strongly suggests
- // an SSLv2 client.
- if want == recordTypeHandshake && typ == 0x80 {
- c.sendAlert(alertProtocolVersion)
- return c.in.setErrorLocked(errors.New("tls: unsupported SSLv2 handshake received"))
- }
-
- vers := uint16(b.data[1])<<8 | uint16(b.data[2])
- n := int(b.data[3])<<8 | int(b.data[4])
- if c.haveVers && vers != c.vers {
- c.sendAlert(alertProtocolVersion)
- return c.in.setErrorLocked(fmt.Errorf("tls: received record with version %x when expecting version %x", vers, c.vers))
- }
- if n > maxCiphertext {
- c.sendAlert(alertRecordOverflow)
- return c.in.setErrorLocked(fmt.Errorf("tls: oversized record received with length %d", n))
- }
- if !c.haveVers {
- // First message, be extra suspicious:
- // this might not be a TLS client.
- // Bail out before reading a full 'body', if possible.
- // The current max version is 3.1.
- // If the version is >= 16.0, it's probably not real.
- // Similarly, a clientHello message encodes in
- // well under a kilobyte. If the length is >= 12 kB,
- // it's probably not real.
- if (typ != recordTypeAlert && typ != want) || vers >= 0x1000 || n >= 0x3000 {
- c.sendAlert(alertUnexpectedMessage)
- return c.in.setErrorLocked(fmt.Errorf("tls: first record does not look like a TLS handshake"))
- }
- }
- if err := b.readFromUntil(c.conn, recordHeaderLen+n); err != nil {
- if err == io.EOF {
- err = io.ErrUnexpectedEOF
- }
- if e, ok := err.(net.Error); !ok || !e.Temporary() {
- c.in.setErrorLocked(err)
- }
- return err
- }
-
- // Process message.
- b, c.rawInput = c.in.splitBlock(b, recordHeaderLen+n)
- ok, off, err := c.in.decrypt(b)
- if !ok {
- c.in.setErrorLocked(c.sendAlert(err))
- }
- b.off = off
- data := b.data[b.off:]
- if len(data) > maxPlaintext {
- err := c.sendAlert(alertRecordOverflow)
- c.in.freeBlock(b)
- return c.in.setErrorLocked(err)
- }
-
- switch typ {
- default:
- c.in.setErrorLocked(c.sendAlert(alertUnexpectedMessage))
-
- case recordTypeAlert:
- if len(data) != 2 {
- c.in.setErrorLocked(c.sendAlert(alertUnexpectedMessage))
- break
- }
- if alert(data[1]) == alertCloseNotify {
- c.in.setErrorLocked(io.EOF)
- break
- }
- switch data[0] {
- case alertLevelWarning:
- // drop on the floor
- c.in.freeBlock(b)
- goto Again
- case alertLevelError:
- c.in.setErrorLocked(&net.OpError{Op: "remote error", Err: alert(data[1])})
- default:
- c.in.setErrorLocked(c.sendAlert(alertUnexpectedMessage))
- }
-
- case recordTypeChangeCipherSpec:
- if typ != want || len(data) != 1 || data[0] != 1 {
- c.in.setErrorLocked(c.sendAlert(alertUnexpectedMessage))
- break
- }
- err := c.in.changeCipherSpec()
- if err != nil {
- c.in.setErrorLocked(c.sendAlert(err.(alert)))
- }
-
- case recordTypeApplicationData:
- if typ != want {
- c.in.setErrorLocked(c.sendAlert(alertUnexpectedMessage))
- break
- }
- c.input = b
- b = nil
-
- case recordTypeHandshake:
- // TODO(rsc): Should at least pick off connection close.
- if typ != want {
- return c.in.setErrorLocked(c.sendAlert(alertNoRenegotiation))
- }
- c.hand.Write(data)
- }
-
- if b != nil {
- c.in.freeBlock(b)
- }
- return c.in.err
-}
-
-// sendAlert sends a TLS alert message.
-// c.out.Mutex <= L.
-func (c *Conn) sendAlertLocked(err alert) error {
- switch err {
- case alertNoRenegotiation, alertCloseNotify:
- c.tmp[0] = alertLevelWarning
- default:
- c.tmp[0] = alertLevelError
- }
- c.tmp[1] = byte(err)
- c.writeRecord(recordTypeAlert, c.tmp[0:2])
- // closeNotify is a special case in that it isn't an error:
- if err != alertCloseNotify {
- return c.out.setErrorLocked(&net.OpError{Op: "local error", Err: err})
- }
- return nil
-}
-
-// sendAlert sends a TLS alert message.
-// L < c.out.Mutex.
-func (c *Conn) sendAlert(err alert) error {
- c.out.Lock()
- defer c.out.Unlock()
- return c.sendAlertLocked(err)
-}
-
-// writeRecord writes a TLS record with the given type and payload
-// to the connection and updates the record layer state.
-// c.out.Mutex <= L.
-func (c *Conn) writeRecord(typ recordType, data []byte) (n int, err error) {
- b := c.out.newBlock()
- for len(data) > 0 {
- m := len(data)
- if m > maxPlaintext {
- m = maxPlaintext
- }
- explicitIVLen := 0
- explicitIVIsSeq := false
-
- var cbc cbcMode
- if c.out.version >= VersionTLS11 {
- var ok bool
- if cbc, ok = c.out.cipher.(cbcMode); ok {
- explicitIVLen = cbc.BlockSize()
- }
- }
- if explicitIVLen == 0 {
- if _, ok := c.out.cipher.(cipher.AEAD); ok {
- explicitIVLen = 8
- // The AES-GCM construction in TLS has an
- // explicit nonce so that the nonce can be
- // random. However, the nonce is only 8 bytes
- // which is too small for a secure, random
- // nonce. Therefore we use the sequence number
- // as the nonce.
- explicitIVIsSeq = true
- }
- }
- b.resize(recordHeaderLen + explicitIVLen + m)
- b.data[0] = byte(typ)
- vers := c.vers
- if vers == 0 {
- // Some TLS servers fail if the record version is
- // greater than TLS 1.0 for the initial ClientHello.
- vers = VersionTLS10
- }
- b.data[1] = byte(vers >> 8)
- b.data[2] = byte(vers)
- b.data[3] = byte(m >> 8)
- b.data[4] = byte(m)
- if explicitIVLen > 0 {
- explicitIV := b.data[recordHeaderLen : recordHeaderLen+explicitIVLen]
- if explicitIVIsSeq {
- copy(explicitIV, c.out.seq[:])
- } else {
- if _, err = io.ReadFull(c.config.rand(), explicitIV); err != nil {
- break
- }
- }
- }
- copy(b.data[recordHeaderLen+explicitIVLen:], data)
- c.out.encrypt(b, explicitIVLen)
- _, err = c.conn.Write(b.data)
- if err != nil {
- break
- }
- n += m
- data = data[m:]
- }
- c.out.freeBlock(b)
-
- if typ == recordTypeChangeCipherSpec {
- err = c.out.changeCipherSpec()
- if err != nil {
- // Cannot call sendAlert directly,
- // because we already hold c.out.Mutex.
- c.tmp[0] = alertLevelError
- c.tmp[1] = byte(err.(alert))
- c.writeRecord(recordTypeAlert, c.tmp[0:2])
- return n, c.out.setErrorLocked(&net.OpError{Op: "local error", Err: err})
- }
- }
- return
-}
-
-// readHandshake reads the next handshake message from
-// the record layer.
-// c.in.Mutex < L; c.out.Mutex < L.
-func (c *Conn) readHandshake() (interface{}, error) {
- for c.hand.Len() < 4 {
- if err := c.in.err; err != nil {
- return nil, err
- }
- if err := c.readRecord(recordTypeHandshake); err != nil {
- return nil, err
- }
- }
-
- data := c.hand.Bytes()
- n := int(data[1])<<16 | int(data[2])<<8 | int(data[3])
- if n > maxHandshake {
- return nil, c.in.setErrorLocked(c.sendAlert(alertInternalError))
- }
- for c.hand.Len() < 4+n {
- if err := c.in.err; err != nil {
- return nil, err
- }
- if err := c.readRecord(recordTypeHandshake); err != nil {
- return nil, err
- }
- }
- data = c.hand.Next(4 + n)
- var m handshakeMessage
- switch data[0] {
- case typeClientHello:
- m = new(clientHelloMsg)
- case typeServerHello:
- m = new(serverHelloMsg)
- case typeNewSessionTicket:
- m = new(newSessionTicketMsg)
- case typeCertificate:
- m = new(certificateMsg)
- case typeCertificateRequest:
- m = &certificateRequestMsg{
- hasSignatureAndHash: c.vers >= VersionTLS12,
- }
- case typeCertificateStatus:
- m = new(certificateStatusMsg)
- case typeServerKeyExchange:
- m = new(serverKeyExchangeMsg)
- case typeServerHelloDone:
- m = new(serverHelloDoneMsg)
- case typeClientKeyExchange:
- m = new(clientKeyExchangeMsg)
- case typeCertificateVerify:
- m = &certificateVerifyMsg{
- hasSignatureAndHash: c.vers >= VersionTLS12,
- }
- case typeNextProtocol:
- m = new(nextProtoMsg)
- case typeFinished:
- m = new(finishedMsg)
- default:
- return nil, c.in.setErrorLocked(c.sendAlert(alertUnexpectedMessage))
- }
-
- // The handshake message unmarshallers
- // expect to be able to keep references to data,
- // so pass in a fresh copy that won't be overwritten.
- data = append([]byte(nil), data...)
-
- if !m.unmarshal(data) {
- return nil, c.in.setErrorLocked(c.sendAlert(alertUnexpectedMessage))
- }
- return m, nil
-}
-
-// Write writes data to the connection.
-func (c *Conn) Write(b []byte) (int, error) {
- if err := c.Handshake(); err != nil {
- return 0, err
- }
-
- c.out.Lock()
- defer c.out.Unlock()
-
- if err := c.out.err; err != nil {
- return 0, err
- }
-
- if !c.handshakeComplete {
- return 0, alertInternalError
- }
-
- // SSL 3.0 and TLS 1.0 are susceptible to a chosen-plaintext
- // attack when using block mode ciphers due to predictable IVs.
- // This can be prevented by splitting each Application Data
- // record into two records, effectively randomizing the IV.
- //
- // http://www.openssl.org/~bodo/tls-cbc.txt
- // https://bugzilla.mozilla.org/show_bug.cgi?id=665814
- // http://www.imperialviolet.org/2012/01/15/beastfollowup.html
-
- var m int
- if len(b) > 1 && c.vers <= VersionTLS10 {
- if _, ok := c.out.cipher.(cipher.BlockMode); ok {
- n, err := c.writeRecord(recordTypeApplicationData, b[:1])
- if err != nil {
- return n, c.out.setErrorLocked(err)
- }
- m, b = 1, b[1:]
- }
- }
-
- n, err := c.writeRecord(recordTypeApplicationData, b)
- return n + m, c.out.setErrorLocked(err)
-}
-
-// 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 (c *Conn) Read(b []byte) (n int, err error) {
- if err = c.Handshake(); err != nil {
- return
- }
- if len(b) == 0 {
- // Put this after Handshake, in case people were calling
- // Read(nil) for the side effect of the Handshake.
- return
- }
-
- c.in.Lock()
- defer c.in.Unlock()
-
- // Some OpenSSL servers send empty records in order to randomize the
- // CBC IV. So this loop ignores a limited number of empty records.
- const maxConsecutiveEmptyRecords = 100
- for emptyRecordCount := 0; emptyRecordCount <= maxConsecutiveEmptyRecords; emptyRecordCount++ {
- for c.input == nil && c.in.err == nil {
- if err := c.readRecord(recordTypeApplicationData); err != nil {
- // Soft error, like EAGAIN
- return 0, err
- }
- }
- if err := c.in.err; err != nil {
- return 0, err
- }
-
- n, err = c.input.Read(b)
- if c.input.off >= len(c.input.data) {
- c.in.freeBlock(c.input)
- c.input = nil
- }
-
- // If a close-notify alert is waiting, read it so that
- // we can return (n, EOF) instead of (n, nil), to signal
- // to the HTTP response reading goroutine that the
- // connection is now closed. This eliminates a race
- // where the HTTP response reading goroutine would
- // otherwise not observe the EOF until its next read,
- // by which time a client goroutine might have already
- // tried to reuse the HTTP connection for a new
- // request.
- // See https://codereview.appspot.com/76400046
- // and http://golang.org/issue/3514
- if ri := c.rawInput; ri != nil &&
- n != 0 && err == nil &&
- c.input == nil && len(ri.data) > 0 && recordType(ri.data[0]) == recordTypeAlert {
- if recErr := c.readRecord(recordTypeApplicationData); recErr != nil {
- err = recErr // will be io.EOF on closeNotify
- }
- }
-
- if n != 0 || err != nil {
- return n, err
- }
- }
-
- return 0, io.ErrNoProgress
-}
-
-// Close closes the connection.
-func (c *Conn) Close() error {
- var alertErr error
-
- c.handshakeMutex.Lock()
- defer c.handshakeMutex.Unlock()
- if c.handshakeComplete {
- alertErr = c.sendAlert(alertCloseNotify)
- }
-
- if err := c.conn.Close(); err != nil {
- return err
- }
- return alertErr
-}
-
-// 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 (c *Conn) Handshake() error {
- c.handshakeMutex.Lock()
- defer c.handshakeMutex.Unlock()
- if err := c.handshakeErr; err != nil {
- return err
- }
- if c.handshakeComplete {
- return nil
- }
-
- if c.isClient {
- c.handshakeErr = c.clientHandshake()
- } else {
- c.handshakeErr = c.serverHandshake()
- }
- return c.handshakeErr
-}
-
-// ConnectionState returns basic TLS details about the connection.
-func (c *Conn) ConnectionState() ConnectionState {
- c.handshakeMutex.Lock()
- defer c.handshakeMutex.Unlock()
-
- var state ConnectionState
- state.HandshakeComplete = c.handshakeComplete
- if c.handshakeComplete {
- state.Version = c.vers
- state.NegotiatedProtocol = c.clientProtocol
- state.DidResume = c.didResume
- state.NegotiatedProtocolIsMutual = !c.clientProtocolFallback
- state.CipherSuite = c.cipherSuite
- state.PeerCertificates = c.peerCertificates
- state.VerifiedChains = c.verifiedChains
- state.ServerName = c.serverName
- if !c.didResume {
- state.TLSUnique = c.firstFinished[:]
- }
- }
-
- return state
-}
-
-// OCSPResponse returns the stapled OCSP response from the TLS server, if
-// any. (Only valid for client connections.)
-func (c *Conn) OCSPResponse() []byte {
- c.handshakeMutex.Lock()
- defer c.handshakeMutex.Unlock()
-
- return c.ocspResponse
-}
-
-// 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 (c *Conn) VerifyHostname(host string) error {
- c.handshakeMutex.Lock()
- defer c.handshakeMutex.Unlock()
- if !c.isClient {
- return errors.New("tls: VerifyHostname called on TLS server connection")
- }
- if !c.handshakeComplete {
- return errors.New("tls: handshake has not yet been performed")
- }
- return c.peerCertificates[0].VerifyHostname(host)
-}
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