262 lines
6.3 KiB
Go
262 lines
6.3 KiB
Go
// Copyright 2012 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 (
|
|
"bytes"
|
|
"crypto/aes"
|
|
"crypto/cipher"
|
|
"crypto/hmac"
|
|
"crypto/sha256"
|
|
"crypto/subtle"
|
|
"errors"
|
|
"io"
|
|
)
|
|
|
|
// sessionState contains the information that is serialized into a session
|
|
// ticket in order to later resume a connection.
|
|
type sessionState struct {
|
|
vers uint16
|
|
cipherSuite uint16
|
|
masterSecret []byte
|
|
certificates [][]byte
|
|
// usedOldKey is true if the ticket from which this session came from
|
|
// was encrypted with an older key and thus should be refreshed.
|
|
usedOldKey bool
|
|
}
|
|
|
|
func (s *sessionState) equal(i interface{}) bool {
|
|
s1, ok := i.(*sessionState)
|
|
if !ok {
|
|
return false
|
|
}
|
|
|
|
if s.vers != s1.vers ||
|
|
s.cipherSuite != s1.cipherSuite ||
|
|
!bytes.Equal(s.masterSecret, s1.masterSecret) {
|
|
return false
|
|
}
|
|
|
|
if len(s.certificates) != len(s1.certificates) {
|
|
return false
|
|
}
|
|
|
|
for i := range s.certificates {
|
|
if !bytes.Equal(s.certificates[i], s1.certificates[i]) {
|
|
return false
|
|
}
|
|
}
|
|
|
|
return true
|
|
}
|
|
|
|
func (s *sessionState) marshal() []byte {
|
|
length := 2 + 2 + 2 + len(s.masterSecret) + 2
|
|
for _, cert := range s.certificates {
|
|
length += 4 + len(cert)
|
|
}
|
|
|
|
ret := make([]byte, length)
|
|
x := ret
|
|
x[0] = byte(s.vers >> 8)
|
|
x[1] = byte(s.vers)
|
|
x[2] = byte(s.cipherSuite >> 8)
|
|
x[3] = byte(s.cipherSuite)
|
|
x[4] = byte(len(s.masterSecret) >> 8)
|
|
x[5] = byte(len(s.masterSecret))
|
|
x = x[6:]
|
|
copy(x, s.masterSecret)
|
|
x = x[len(s.masterSecret):]
|
|
|
|
x[0] = byte(len(s.certificates) >> 8)
|
|
x[1] = byte(len(s.certificates))
|
|
x = x[2:]
|
|
|
|
for _, cert := range s.certificates {
|
|
x[0] = byte(len(cert) >> 24)
|
|
x[1] = byte(len(cert) >> 16)
|
|
x[2] = byte(len(cert) >> 8)
|
|
x[3] = byte(len(cert))
|
|
copy(x[4:], cert)
|
|
x = x[4+len(cert):]
|
|
}
|
|
|
|
return ret
|
|
}
|
|
|
|
func (s *sessionState) unmarshal(data []byte) bool {
|
|
if len(data) < 8 {
|
|
return false
|
|
}
|
|
|
|
s.vers = uint16(data[0])<<8 | uint16(data[1])
|
|
s.cipherSuite = uint16(data[2])<<8 | uint16(data[3])
|
|
masterSecretLen := int(data[4])<<8 | int(data[5])
|
|
data = data[6:]
|
|
if len(data) < masterSecretLen {
|
|
return false
|
|
}
|
|
|
|
s.masterSecret = data[:masterSecretLen]
|
|
data = data[masterSecretLen:]
|
|
|
|
if len(data) < 2 {
|
|
return false
|
|
}
|
|
|
|
numCerts := int(data[0])<<8 | int(data[1])
|
|
data = data[2:]
|
|
|
|
s.certificates = make([][]byte, numCerts)
|
|
for i := range s.certificates {
|
|
if len(data) < 4 {
|
|
return false
|
|
}
|
|
certLen := int(data[0])<<24 | int(data[1])<<16 | int(data[2])<<8 | int(data[3])
|
|
data = data[4:]
|
|
if certLen < 0 {
|
|
return false
|
|
}
|
|
if len(data) < certLen {
|
|
return false
|
|
}
|
|
s.certificates[i] = data[:certLen]
|
|
data = data[certLen:]
|
|
}
|
|
|
|
return len(data) == 0
|
|
}
|
|
|
|
type sessionState13 struct {
|
|
vers uint16
|
|
hash uint16 // crypto.Hash value
|
|
ageAdd uint32
|
|
createdAt uint64
|
|
resumptionSecret []byte
|
|
}
|
|
|
|
func (s *sessionState13) equal(i interface{}) bool {
|
|
s1, ok := i.(*sessionState13)
|
|
if !ok {
|
|
return false
|
|
}
|
|
|
|
return s.vers == s1.vers &&
|
|
s.hash == s1.hash &&
|
|
s.ageAdd == s1.ageAdd &&
|
|
bytes.Equal(s.resumptionSecret, s1.resumptionSecret)
|
|
}
|
|
|
|
func (s *sessionState13) marshal() []byte {
|
|
length := 2 + 2 + 4 + 8 + 2 + len(s.resumptionSecret)
|
|
|
|
x := make([]byte, length)
|
|
x[0] = byte(s.vers >> 8)
|
|
x[1] = byte(s.vers)
|
|
x[2] = byte(s.hash >> 8)
|
|
x[3] = byte(s.hash)
|
|
x[4] = byte(s.ageAdd >> 24)
|
|
x[5] = byte(s.ageAdd >> 16)
|
|
x[6] = byte(s.ageAdd >> 8)
|
|
x[7] = byte(s.ageAdd)
|
|
x[8] = byte(s.createdAt >> 56)
|
|
x[9] = byte(s.createdAt >> 48)
|
|
x[10] = byte(s.createdAt >> 40)
|
|
x[11] = byte(s.createdAt >> 32)
|
|
x[12] = byte(s.createdAt >> 24)
|
|
x[13] = byte(s.createdAt >> 16)
|
|
x[14] = byte(s.createdAt >> 8)
|
|
x[15] = byte(s.createdAt)
|
|
x[16] = byte(len(s.resumptionSecret) >> 8)
|
|
x[17] = byte(len(s.resumptionSecret))
|
|
|
|
copy(x[18:], s.resumptionSecret)
|
|
|
|
return x
|
|
}
|
|
|
|
func (s *sessionState13) unmarshal(data []byte) bool {
|
|
if len(data) < 18 {
|
|
return false
|
|
}
|
|
|
|
s.vers = uint16(data[0])<<8 | uint16(data[1])
|
|
s.hash = uint16(data[2])<<8 | uint16(data[3])
|
|
s.ageAdd = uint32(data[4])<<24 | uint32(data[5])<<16 | uint32(data[6])<<8 | uint32(data[7])
|
|
s.createdAt = uint64(data[8])<<56 | uint64(data[9])<<48 | uint64(data[10])<<40 | uint64(data[11])<<32 |
|
|
uint64(data[12])<<24 | uint64(data[13])<<16 | uint64(data[14])<<8 | uint64(data[15])
|
|
l := uint16(data[16])<<8 | uint16(data[17])
|
|
s.resumptionSecret = data[18:]
|
|
|
|
return int(l) == len(s.resumptionSecret)
|
|
}
|
|
|
|
func (c *Conn) encryptTicket(serialized []byte) ([]byte, error) {
|
|
encrypted := make([]byte, ticketKeyNameLen+aes.BlockSize+len(serialized)+sha256.Size)
|
|
keyName := encrypted[:ticketKeyNameLen]
|
|
iv := encrypted[ticketKeyNameLen : ticketKeyNameLen+aes.BlockSize]
|
|
macBytes := encrypted[len(encrypted)-sha256.Size:]
|
|
|
|
if _, err := io.ReadFull(c.config.rand(), iv); err != nil {
|
|
return nil, err
|
|
}
|
|
key := c.config.ticketKeys()[0]
|
|
copy(keyName, key.keyName[:])
|
|
block, err := aes.NewCipher(key.aesKey[:])
|
|
if err != nil {
|
|
return nil, errors.New("tls: failed to create cipher while encrypting ticket: " + err.Error())
|
|
}
|
|
cipher.NewCTR(block, iv).XORKeyStream(encrypted[ticketKeyNameLen+aes.BlockSize:], serialized)
|
|
|
|
mac := hmac.New(sha256.New, key.hmacKey[:])
|
|
mac.Write(encrypted[:len(encrypted)-sha256.Size])
|
|
mac.Sum(macBytes[:0])
|
|
|
|
return encrypted, nil
|
|
}
|
|
|
|
func (c *Conn) decryptTicket(encrypted []byte) (serialized []byte, usedOldKey bool) {
|
|
if c.config.SessionTicketsDisabled ||
|
|
len(encrypted) < ticketKeyNameLen+aes.BlockSize+sha256.Size {
|
|
return nil, false
|
|
}
|
|
|
|
keyName := encrypted[:ticketKeyNameLen]
|
|
iv := encrypted[ticketKeyNameLen : ticketKeyNameLen+aes.BlockSize]
|
|
macBytes := encrypted[len(encrypted)-sha256.Size:]
|
|
|
|
keys := c.config.ticketKeys()
|
|
keyIndex := -1
|
|
for i, candidateKey := range keys {
|
|
if bytes.Equal(keyName, candidateKey.keyName[:]) {
|
|
keyIndex = i
|
|
break
|
|
}
|
|
}
|
|
|
|
if keyIndex == -1 {
|
|
return nil, false
|
|
}
|
|
key := &keys[keyIndex]
|
|
|
|
mac := hmac.New(sha256.New, key.hmacKey[:])
|
|
mac.Write(encrypted[:len(encrypted)-sha256.Size])
|
|
expected := mac.Sum(nil)
|
|
|
|
if subtle.ConstantTimeCompare(macBytes, expected) != 1 {
|
|
return nil, false
|
|
}
|
|
|
|
block, err := aes.NewCipher(key.aesKey[:])
|
|
if err != nil {
|
|
return nil, false
|
|
}
|
|
ciphertext := encrypted[ticketKeyNameLen+aes.BlockSize : len(encrypted)-sha256.Size]
|
|
plaintext := ciphertext
|
|
cipher.NewCTR(block, iv).XORKeyStream(plaintext, ciphertext)
|
|
|
|
return plaintext, keyIndex > 0
|
|
}
|