third_party/tlslite/patches/extended_master_secret.patch

   1 diff --git a/third_party/tlslite/tlslite/constants.py b/third_party/tlslite/tlslite/constants.py
   2 index 6d78a20..f9c8676 100644
   3 --- a/third_party/tlslite/tlslite/constants.py
   4 +++ b/third_party/tlslite/tlslite/constants.py
   5 @@ -55,6 +55,7 @@ class ExtensionType:    # RFC 6066 / 4366
   6      srp = 12            # RFC 5054
   7      cert_type = 9       # RFC 6091
   8      signed_cert_timestamps = 18  # RFC 6962
   9 +    extended_master_secret = 23  # draft-ietf-tls-session-hash-06
  10      tack = 0xF300
  11      supports_npn = 13172
  12      channel_id = 30032
  13 diff --git a/third_party/tlslite/tlslite/handshakesettings.py b/third_party/tlslite/tlslite/handshakesettings.py
  14 index 605ed42..a7b6ab9 100644
  15 --- a/third_party/tlslite/tlslite/handshakesettings.py
  16 +++ b/third_party/tlslite/tlslite/handshakesettings.py
  17 @@ -111,6 +111,10 @@ class HandshakeSettings(object):
  18      @type alertAfterHandshake: bool
  19      @ivar alertAfterHandshake: If true, the server will send a fatal
  20      alert immediately after the handshake completes.
  21 +
  22 +    @type enableExtendedMasterSecret: bool
  23 +    @ivar enableExtendedMasterSecret: If true, the server supports the extended
  24 +    master secret TLS extension and will negotiated it with supporting clients.
  25
  26      Note that TACK support is not standardized by IETF and uses a temporary
  27      TLS Extension number, so should NOT be used in production software.
  28 @@ -129,6 +133,7 @@ class HandshakeSettings(object):
  29          self.tlsIntoleranceType = 'alert'
  30          self.useExperimentalTackExtension = False
  31          self.alertAfterHandshake = False
  32 +        self.enableExtendedMasterSecret = True
  33
  34      # Validates the min/max fields, and certificateTypes
  35      # Filters out unsupported cipherNames and cipherImplementations
  36 @@ -146,6 +151,7 @@ class HandshakeSettings(object):
  37          other.tlsIntolerant = self.tlsIntolerant
  38          other.tlsIntoleranceType = self.tlsIntoleranceType
  39          other.alertAfterHandshake = self.alertAfterHandshake
  40 +        other.enableExtendedMasterSecret = self.enableExtendedMasterSecret
  41
  42          if not cipherfactory.tripleDESPresent:
  43              other.cipherNames = [e for e in self.cipherNames if e != "3des"]
  44 diff --git a/third_party/tlslite/tlslite/mathtls.py b/third_party/tlslite/tlslite/mathtls.py
  45 index 60a331a..0a23fe1 100644
  46 --- a/third_party/tlslite/tlslite/mathtls.py
  47 +++ b/third_party/tlslite/tlslite/mathtls.py
  48 @@ -67,16 +67,20 @@ def PRF_SSL(secret, seed, length):
  49              index += 1
  50      return bytes
  51
  52 -def calcMasterSecret(version, premasterSecret, clientRandom, serverRandom):
  53 +def calcMasterSecret(version, premasterSecret, clientRandom, serverRandom,
  54 +                     handshakeHash, useExtendedMasterSecret):
  55 +    label = b"master secret"
  56 +    seed = clientRandom + serverRandom
  57 +    if useExtendedMasterSecret:
  58 +        label = b"extended master secret"
  59 +        seed = handshakeHash
  60 +
  61      if version == (3,0):
  62 -        masterSecret = PRF_SSL(premasterSecret,
  63 -                            clientRandom + serverRandom, 48)
  64 +        masterSecret = PRF_SSL(premasterSecret, seed, 48)
  65      elif version in ((3,1), (3,2)):
  66 -        masterSecret = PRF(premasterSecret, b"master secret",
  67 -                            clientRandom + serverRandom, 48)
  68 +        masterSecret = PRF(premasterSecret, label, seed, 48)
  69      elif version == (3,3):
  70 -        masterSecret = PRF_1_2(premasterSecret, b"master secret",
  71 -                            clientRandom + serverRandom, 48)
  72 +        masterSecret = PRF_1_2(premasterSecret, label, seed, 48)
  73      else:
  74          raise AssertionError()
  75      return masterSecret
  76 diff --git a/third_party/tlslite/tlslite/messages.py b/third_party/tlslite/tlslite/messages.py
  77 index 9aeff6d..9b553ce 100644
  78 --- a/third_party/tlslite/tlslite/messages.py
  79 +++ b/third_party/tlslite/tlslite/messages.py
  80 @@ -114,6 +114,7 @@ class ClientHello(HandshakeMsg):
  81          self.supports_npn = False
  82          self.server_name = bytearray(0)
  83          self.channel_id = False
  84 +        self.extended_master_secret = False
  85          self.support_signed_cert_timestamps = False
  86          self.status_request = False
  87
  88 @@ -185,6 +186,8 @@ class ClientHello(HandshakeMsg):
  89                                  break
  90                      elif extType == ExtensionType.channel_id:
  91                          self.channel_id = True
  92 +                    elif extType == ExtensionType.extended_master_secret:
  93 +                        self.extended_master_secret = True
  94                      elif extType == ExtensionType.signed_cert_timestamps:
  95                          if extLength:
  96                              raise SyntaxError()
  97 @@ -267,6 +270,7 @@ class ServerHello(HandshakeMsg):
  98          self.next_protos_advertised = None
  99          self.next_protos = None
 100          self.channel_id = False
 101 +        self.extended_master_secret = False
 102          self.signed_cert_timestamps = None
 103          self.status_request = False
 104
 105 @@ -358,6 +362,9 @@ class ServerHello(HandshakeMsg):
 106          if self.channel_id:
 107              w2.add(ExtensionType.channel_id, 2)
 108              w2.add(0, 2)
 109 +        if self.extended_master_secret:
 110 +            w2.add(ExtensionType.extended_master_secret, 2)
 111 +            w2.add(0, 2)
 112          if self.signed_cert_timestamps:
 113              w2.add(ExtensionType.signed_cert_timestamps, 2)
 114              w2.addVarSeq(bytearray(self.signed_cert_timestamps), 1, 2)
 115 diff --git a/third_party/tlslite/tlslite/tlsconnection.py b/third_party/tlslite/tlslite/tlsconnection.py
 116 index dfac274..04161513 100644
 117 --- a/third_party/tlslite/tlslite/tlsconnection.py
 118 +++ b/third_party/tlslite/tlslite/tlsconnection.py
 119 @@ -981,7 +981,8 @@ class TLSConnection(TLSRecordLayer):
 120                  masterSecret = calcMasterSecret(self.version,
 121                                           premasterSecret,
 122                                           clientRandom,
 123 -                                         serverRandom)
 124 +                                         serverRandom,
 125 +                                         b"", False)
 126                  verifyBytes = self._calcSSLHandshakeHash(masterSecret, b"")
 127              elif self.version in ((3,1), (3,2)):
 128                  verifyBytes = self._handshake_md5.digest() + \
 129 @@ -1036,7 +1037,7 @@ class TLSConnection(TLSRecordLayer):
 130                          cipherSuite, cipherImplementations, nextProto):
 131
 132          masterSecret = calcMasterSecret(self.version, premasterSecret,
 133 -                            clientRandom, serverRandom)
 134 +                            clientRandom, serverRandom, b"", False)
 135          self._calcPendingStates(cipherSuite, masterSecret,
 136                                  clientRandom, serverRandom,
 137                                  cipherImplementations)
 138 @@ -1326,6 +1327,9 @@ class TLSConnection(TLSRecordLayer):
 139                              cipherSuite, CertificateType.x509, tackExt,
 140                              nextProtos)
 141          serverHello.channel_id = clientHello.channel_id
 142 +        serverHello.extended_master_secret = \
 143 +            clientHello.extended_master_secret and \
 144 +            settings.enableExtendedMasterSecret
 145          if clientHello.support_signed_cert_timestamps:
 146              serverHello.signed_cert_timestamps = signedCertTimestamps
 147          if clientHello.status_request:
 148 @@ -1383,7 +1387,8 @@ class TLSConnection(TLSRecordLayer):
 149          for result in self._serverFinished(premasterSecret,
 150                                  clientHello.random, serverHello.random,
 151                                  cipherSuite, settings.cipherImplementations,
 152 -                                nextProtos, clientHello.channel_id):
 153 +                                nextProtos, clientHello.channel_id,
 154 +                                serverHello.extended_master_secret):
 155                  if result in (0,1): yield result
 156                  else: break
 157          masterSecret = result
 158 @@ -1523,6 +1528,9 @@ class TLSConnection(TLSRecordLayer):
 159                  serverHello.create(self.version, getRandomBytes(32),
 160                                     session.sessionID, session.cipherSuite,
 161                                     CertificateType.x509, None, None)
 162 +                serverHello.extended_master_secret = \
 163 +                    clientHello.extended_master_secret and \
 164 +                    settings.enableExtendedMasterSecret
 165                  for result in self._sendMsg(serverHello):
 166                      yield result
 167
 168 @@ -1743,7 +1751,8 @@ class TLSConnection(TLSRecordLayer):
 169          if clientCertChain:
 170              if self.version == (3,0):
 171                  masterSecret = calcMasterSecret(self.version, premasterSecret,
 172 -                                         clientHello.random, serverHello.random)
 173 +                                         clientHello.random, serverHello.random,
 174 +                                         b"", False)
 175                  verifyBytes = self._calcSSLHandshakeHash(masterSecret, b"")
 176              elif self.version in ((3,1), (3,2)):
 177                  verifyBytes = self._handshake_md5.digest() + \
 178 @@ -1827,9 +1836,11 @@ class TLSConnection(TLSRecordLayer):
 179
 180      def _serverFinished(self,  premasterSecret, clientRandom, serverRandom,
 181                          cipherSuite, cipherImplementations, nextProtos,
 182 -                        doingChannelID):
 183 +                        doingChannelID, useExtendedMasterSecret):
 184          masterSecret = calcMasterSecret(self.version, premasterSecret,
 185 -                                      clientRandom, serverRandom)
 186 +                                      clientRandom, serverRandom,
 187 +                                      self._ems_handshake_hash,
 188 +                                      useExtendedMasterSecret)
 189
 190          #Calculate pending connection states
 191          self._calcPendingStates(cipherSuite, masterSecret,
 192 diff --git a/third_party/tlslite/tlslite/tlsrecordlayer.py b/third_party/tlslite/tlslite/tlsrecordlayer.py
 193 index c3bcd8c..d2320b8 100644
 194 --- a/third_party/tlslite/tlslite/tlsrecordlayer.py
 195 +++ b/third_party/tlslite/tlslite/tlsrecordlayer.py
 196 @@ -119,6 +119,7 @@ class TLSRecordLayer(object):
 197          self._handshake_md5 = hashlib.md5()
 198          self._handshake_sha = hashlib.sha1()
 199          self._handshake_sha256 = hashlib.sha256()
 200 +        self._ems_handshake_hash = b""
 201
 202          #TLS Protocol Version
 203          self.version = (0,0) #read-only
 204 @@ -814,6 +815,8 @@ class TLSRecordLayer(object):
 205                  self._handshake_md5.update(compat26Str(p.bytes))
 206                  self._handshake_sha.update(compat26Str(p.bytes))
 207                  self._handshake_sha256.update(compat26Str(p.bytes))
 208 +                if subType == HandshakeType.client_key_exchange:
 209 +                    self._ems_handshake_hash = self._getHandshakeHash()
 210
 211                  #Parse based on handshake type
 212                  if subType == HandshakeType.client_hello:
 213 @@ -1112,6 +1115,7 @@ class TLSRecordLayer(object):
 214          self._handshake_md5 = hashlib.md5()
 215          self._handshake_sha = hashlib.sha1()
 216          self._handshake_sha256 = hashlib.sha256()
 217 +        self._ems_handshake_hash = b""
 218          self._handshakeBuffer = []
 219          self.allegedSrpUsername = None
 220          self._refCount = 1
 221 @@ -1256,3 +1260,9 @@ class TLSRecordLayer(object):
 222
 223          return md5Bytes + shaBytes
 224
 225 +    def _getHandshakeHash(self):
 226 +        if self.version in ((3,1), (3,2)):
 227 +            return self._handshake_md5.digest() + \
 228 +                self._handshake_sha.digest()
 229 +        elif self.version == (3,3):
 230 +            return self._handshake_sha256.digest()