def process(self, state, msg):
"""Process the Server Key Exchange message"""
assert msg.contentType == ContentType.handshake
parser = Parser(msg.write())
hs_type = parser.get(1)
assert hs_type == HandshakeType.server_key_exchange
if self.version is None:
self.version = state.version
if self.cipher_suite is None:
self.cipher_suite = state.cipher
valid_sig_algs = self.valid_sig_algs
server_key_exchange = ServerKeyExchange(self.cipher_suite,
self.version)
server_key_exchange.parse(parser)
client_random = state.client_random
server_random = state.server_random
public_key = state.get_server_public_key()
server_hello = state.get_last_message_of_type(ServerHello)
if server_hello is None:
server_hello = ServerHello
server_hello.server_version = state.version
if valid_sig_algs is None:
# if the value was unset in script, get the advertised value from
# Client Hello
client_hello = state.get_last_message_of_type(ClientHello)
if client_hello is not None:
sig_algs_ext = client_hello.getExtension(ExtensionType.
signature_algorithms)
if sig_algs_ext is not None:
valid_sig_algs = sig_algs_ext.sigalgs
if valid_sig_algs is None:
# no advertised means support for sha1 only
valid_sig_algs = [(HashAlgorithm.sha1, SignatureAlgorithm.rsa)]
KeyExchange.verifyServerKeyExchange(server_key_exchange,
public_key,
client_random,
server_random,
valid_sig_algs)
state.key_exchange = DHE_RSAKeyExchange(self.cipher_suite,
clientHello=None,
serverHello=server_hello,
privateKey=None)
state.premaster_secret = state.key_exchange.\
processServerKeyExchange(public_key,
server_key_exchange)
state.handshake_messages.append(server_key_exchange)
state.handshake_hashes.update(msg.write())
def process(self, state, msg):
"""Process the Server Key Exchange message"""
assert msg.contentType == ContentType.handshake
parser = Parser(msg.write())
hs_type = parser.get(1)
assert hs_type == HandshakeType.server_key_exchange
if self.version is None:
self.version = state.version
if self.cipher_suite is None:
self.cipher_suite = state.cipher
valid_sig_algs = self.valid_sig_algs
valid_groups = self.valid_groups
server_key_exchange = ServerKeyExchange(self.cipher_suite,
self.version)
server_key_exchange.parse(parser)
client_random = state.client_random
server_random = state.server_random
public_key = state.get_server_public_key()
server_hello = state.get_last_message_of_type(ServerHello)
if server_hello is None:
server_hello = ServerHello
server_hello.server_version = state.version
if valid_sig_algs is None:
# if the value was unset in script, get the advertised value from
# Client Hello
client_hello = state.get_last_message_of_type(ClientHello)
if client_hello is not None:
sig_algs_ext = client_hello.getExtension(
ExtensionType.signature_algorithms)
if sig_algs_ext is not None:
valid_sig_algs = sig_algs_ext.sigalgs
if valid_sig_algs is None:
# no advertised means support for sha1 only
valid_sig_algs = [(HashAlgorithm.sha1, SignatureAlgorithm.rsa)]
KeyExchange.verifyServerKeyExchange(server_key_exchange, public_key,
client_random, server_random,
valid_sig_algs)
if self.cipher_suite in CipherSuite.dhAllSuites:
if valid_groups and any(i in range(256, 512)
for i in valid_groups):
self._checkParams(server_key_exchange)
state.key_exchange = DHE_RSAKeyExchange(self.cipher_suite,
clientHello=None,
serverHello=server_hello,
privateKey=None)
elif self.cipher_suite in CipherSuite.ecdhAllSuites:
# extract valid groups from Client Hello
if valid_groups is None:
client_hello = state.get_last_message_of_type(ClientHello)
if client_hello is not None:
groups_ext = client_hello.getExtension(
ExtensionType.supported_groups)
if groups_ext is not None:
valid_groups = groups_ext.groups
if valid_groups is None:
# no advertised means support for all
valid_groups = GroupName.allEC
state.key_exchange = \
ECDHE_RSAKeyExchange(self.cipher_suite,
clientHello=None,
serverHello=server_hello,
privateKey=None,
acceptedCurves=valid_groups)
else:
raise AssertionError("Unsupported cipher selected")
state.premaster_secret = state.key_exchange.\
processServerKeyExchange(public_key,
server_key_exchange)
state.handshake_messages.append(server_key_exchange)
state.handshake_hashes.update(msg.write())