1 files changed, 186 insertions, 0 deletions
diff --git a/chromium/third_party/tlslite/tlslite/handshakesettings.py b/chromium/third_party/tlslite/tlslite/handshakesettings.py
new file mode 100644
index 00000000000..e0bc0e661c5
--- /dev/null
+++ b/chromium/third_party/tlslite/tlslite/handshakesettings.py
@@ -0,0 +1,186 @@
+# Authors: 
+#   Trevor Perrin
+#   Dave Baggett (Arcode Corporation) - cleanup handling of constants
+#
+# See the LICENSE file for legal information regarding use of this file.
+
+"""Class for setting handshake parameters."""
+
+from .constants import CertificateType
+from .utils import cryptomath
+from .utils import cipherfactory
+
+# RC4 is preferred as faster in Python, works in SSL3, and immune to CBC
+# issues such as timing attacks
+CIPHER_NAMES = ["rc4", "aes256", "aes128", "3des"]
+MAC_NAMES = ["sha"] # Don't allow "md5" by default.
+ALL_MAC_NAMES = ["sha", "md5"]
+KEY_EXCHANGE_NAMES = ["rsa", "dhe_rsa", "srp_sha", "srp_sha_rsa", "dh_anon"]
+CIPHER_IMPLEMENTATIONS = ["openssl", "pycrypto", "python"]
+CERTIFICATE_TYPES = ["x509"]
+
+class HandshakeSettings(object):
+    """This class encapsulates various parameters that can be used with
+    a TLS handshake.
+    @sort: minKeySize, maxKeySize, cipherNames, macNames, certificateTypes,
+    minVersion, maxVersion
+
+    @type minKeySize: int
+    @ivar minKeySize: The minimum bit length for asymmetric keys.
+
+    If the other party tries to use SRP, RSA, or Diffie-Hellman
+    parameters smaller than this length, an alert will be
+    signalled.  The default is 1023.
+
+    @type maxKeySize: int
+    @ivar maxKeySize: The maximum bit length for asymmetric keys.
+
+    If the other party tries to use SRP, RSA, or Diffie-Hellman
+    parameters larger than this length, an alert will be signalled.
+    The default is 8193.
+
+    @type cipherNames: list
+    @ivar cipherNames: The allowed ciphers, in order of preference.
+
+    The allowed values in this list are 'aes256', 'aes128', '3des', and
+    'rc4'.  If these settings are used with a client handshake, they
+    determine the order of the ciphersuites offered in the ClientHello
+    message.
+
+    If these settings are used with a server handshake, the server will
+    choose whichever ciphersuite matches the earliest entry in this
+    list.
+
+    NOTE:  If '3des' is used in this list, but TLS Lite can't find an
+    add-on library that supports 3DES, then '3des' will be silently
+    removed.
+
+    The default value is ['rc4', 'aes256', 'aes128', '3des'].
+
+    @type macNames: list
+    @ivar macNames: The allowed MAC algorithms.
+    
+    The allowed values in this list are 'sha' and 'md5'.
+    
+    The default value is ['sha'].
+
+
+    @type certificateTypes: list
+    @ivar certificateTypes: The allowed certificate types, in order of
+    preference.
+
+    The only allowed certificate type is 'x509'.  This list is only used with a
+    client handshake.  The client will advertise to the server which certificate
+    types are supported, and will check that the server uses one of the
+    appropriate types.
+
+
+    @type minVersion: tuple
+    @ivar minVersion: The minimum allowed SSL/TLS version.
+
+    This variable can be set to (3,0) for SSL 3.0, (3,1) for
+    TLS 1.0, or (3,2) for TLS 1.1.  If the other party wishes to
+    use a lower version, a protocol_version alert will be signalled.
+    The default is (3,0).
+
+    @type maxVersion: tuple
+    @ivar maxVersion: The maximum allowed SSL/TLS version.
+
+    This variable can be set to (3,0) for SSL 3.0, (3,1) for
+    TLS 1.0, or (3,2) for TLS 1.1.  If the other party wishes to
+    use a higher version, a protocol_version alert will be signalled.
+    The default is (3,2).  (WARNING: Some servers may (improperly)
+    reject clients which offer support for TLS 1.1.  In this case,
+    try lowering maxVersion to (3,1)).
+    
+    @type useExperimentalTackExtension: bool
+    @ivar useExperimentalTackExtension: Whether to enabled TACK support.
+    
+    Note that TACK support is not standardized by IETF and uses a temporary
+    TLS Extension number, so should NOT be used in production software.
+    """
+    def __init__(self):
+        self.minKeySize = 1023
+        self.maxKeySize = 8193
+        self.cipherNames = CIPHER_NAMES
+        self.macNames = MAC_NAMES
+        self.keyExchangeNames = KEY_EXCHANGE_NAMES
+        self.cipherImplementations = CIPHER_IMPLEMENTATIONS
+        self.certificateTypes = CERTIFICATE_TYPES
+        self.minVersion = (3,0)
+        self.maxVersion = (3,2)
+        self.useExperimentalTackExtension = False
+
+    # Validates the min/max fields, and certificateTypes
+    # Filters out unsupported cipherNames and cipherImplementations
+    def _filter(self):
+        other = HandshakeSettings()
+        other.minKeySize = self.minKeySize
+        other.maxKeySize = self.maxKeySize
+        other.cipherNames = self.cipherNames
+        other.macNames = self.macNames
+        other.keyExchangeNames = self.keyExchangeNames
+        other.cipherImplementations = self.cipherImplementations
+        other.certificateTypes = self.certificateTypes
+        other.minVersion = self.minVersion
+        other.maxVersion = self.maxVersion
+
+        if not cipherfactory.tripleDESPresent:
+            other.cipherNames = [e for e in self.cipherNames if e != "3des"]
+        if len(other.cipherNames)==0:
+            raise ValueError("No supported ciphers")
+        if len(other.certificateTypes)==0:
+            raise ValueError("No supported certificate types")
+
+        if not cryptomath.m2cryptoLoaded:
+            other.cipherImplementations = \
+                [e for e in other.cipherImplementations if e != "openssl"]
+        if not cryptomath.pycryptoLoaded:
+            other.cipherImplementations = \
+                [e for e in other.cipherImplementations if e != "pycrypto"]
+        if len(other.cipherImplementations)==0:
+            raise ValueError("No supported cipher implementations")
+
+        if other.minKeySize<512:
+            raise ValueError("minKeySize too small")
+        if other.minKeySize>16384:
+            raise ValueError("minKeySize too large")
+        if other.maxKeySize<512:
+            raise ValueError("maxKeySize too small")
+        if other.maxKeySize>16384:
+            raise ValueError("maxKeySize too large")
+        for s in other.cipherNames:
+            if s not in CIPHER_NAMES:
+                raise ValueError("Unknown cipher name: '%s'" % s)
+        for s in other.macNames:
+            if s not in ALL_MAC_NAMES:
+                raise ValueError("Unknown MAC name: '%s'" % s)
+        for s in other.keyExchangeNames:
+            if s not in KEY_EXCHANGE_NAMES:
+                raise ValueError("Unknown key exchange name: '%s'" % s)
+        for s in other.cipherImplementations:
+            if s not in CIPHER_IMPLEMENTATIONS:
+                raise ValueError("Unknown cipher implementation: '%s'" % s)
+        for s in other.certificateTypes:
+            if s not in CERTIFICATE_TYPES:
+                raise ValueError("Unknown certificate type: '%s'" % s)
+
+        if other.minVersion > other.maxVersion:
+            raise ValueError("Versions set incorrectly")
+
+        if not other.minVersion in ((3,0), (3,1), (3,2)):
+            raise ValueError("minVersion set incorrectly")
+
+        if not other.maxVersion in ((3,0), (3,1), (3,2)):
+            raise ValueError("maxVersion set incorrectly")
+
+        return other
+
+    def _getCertificateTypes(self):
+        l = []
+        for ct in self.certificateTypes:
+            if ct == "x509":
+                l.append(CertificateType.x509)
+            else:
+                raise AssertionError()
+        return l