Merged in certs branch in preparation for 0.9.3pre2

git-svn-id: https://svn.mcs.anl.gov/repos/bcfg/trunk/bcfg2@2928 ce84e21b-d406-0410-9b95-82705330c041

1 files changed, 159 insertions, 0 deletions

diff --git a/src/lib/tlslite/HandshakeSettings.py b/src/lib/tlslite/HandshakeSettings.py
new file mode 100755
index 000000000..c7c3223e5
--- /dev/null
+++ b/src/lib/tlslite/HandshakeSettings.py
@@ -0,0 +1,159 @@
+"""Class for setting handshake parameters."""
+
+from constants import CertificateType
+from utils import cryptomath
+from utils import cipherfactory
+
+class HandshakeSettings:
+    """This class encapsulates various parameters that can be used with
+    a TLS handshake.
+    @sort: minKeySize, maxKeySize, cipherNames, 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 ['aes256', 'aes128', '3des', 'rc4'].
+
+    @type certificateTypes: list
+    @ivar certificateTypes: The allowed certificate types, in order of
+    preference.
+
+    The allowed values in this list are 'x509' and 'cryptoID'.  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.
+
+    NOTE:  If 'cryptoID' is used in this list, but cryptoIDlib is not
+    installed, then 'cryptoID' will be silently removed.
+
+    @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)).
+    """
+    def __init__(self):
+        self.minKeySize = 1023
+        self.maxKeySize = 8193
+        self.cipherNames = ["aes256", "aes128", "3des", "rc4"]
+        self.cipherImplementations = ["cryptlib", "openssl", "pycrypto",
+                                      "python"]
+        self.certificateTypes = ["x509", "cryptoID"]
+        self.minVersion = (3,0)
+        self.maxVersion = (3,2)
+
+    #Filters out options that are not supported
+    def _filter(self):
+        other = HandshakeSettings()
+        other.minKeySize = self.minKeySize
+        other.maxKeySize = self.maxKeySize
+        other.cipherNames = self.cipherNames
+        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")
+
+        try:
+            import cryptoIDlib
+        except ImportError:
+            other.certificateTypes = [e for e in self.certificateTypes \
+                                      if e != "cryptoID"]
+        if len(other.certificateTypes)==0:
+            raise ValueError("No supported certificate types")
+
+        if not cryptomath.cryptlibpyLoaded:
+            other.cipherImplementations = [e for e in \
+                self.cipherImplementations if e != "cryptlib"]
+        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 ("aes256", "aes128", "rc4", "3des"):
+                raise ValueError("Unknown cipher name: '%s'" % s)
+        for s in other.cipherImplementations:
+            if s not in ("cryptlib", "openssl", "python", "pycrypto"):
+                raise ValueError("Unknown cipher implementation: '%s'" % s)
+        for s in other.certificateTypes:
+            if s not in ("x509", "cryptoID"):
+                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)
+            elif ct == "cryptoID":
+                l.append(CertificateType.cryptoID)
+            else:
+                raise AssertionError()
+        return l