aboutsummaryrefslogtreecommitdiff
path: root/projects/hsm/cryptech_probe
blob: 16a2a8f6604bacaad94aceaa6d86edc9140279cf (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
#!/usr/bin/env python
#
# Copyright (c) 2016, NORDUnet A/S All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
# - Redistributions of source code must retain the above copyright notice,
#   this list of conditions and the following disclaimer.
#
# - Redistributions in binary form must reproduce the above copyright
#   notice, this list of conditions and the following disclaimer in the
#   documentation and/or other materials provided with the distribution.
#
# - Neither the name of the NORDUnet nor the names of its contributors may
#   be used to endorse or promote products derived from this software
#   without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
# IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
# TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

"""
Utility to probe USB serial port(s) trying to figure out which one(s)
we have plugged in today.
"""

import sys
import time
import argparse
import serial.tools.list_ports_posix

parser = argparse.ArgumentParser(formatter_class = argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument("-v", "--verbose", action = "store_true", help = "blather about what we're doing")
args = parser.parse_args()

SLIP_END     = chr(0300)        # Indicates end of SLIP packet
SLIP_ESC     = chr(0333)        # Indicates byte stuffing
SLIP_ESC_END = chr(0334)        # ESC ESC_END means END data byte
SLIP_ESC_ESC = chr(0335)        # ESC ESC_ESC means ESC data byte

Control_U    = chr(0025)        # Console: clear line
Control_M    = chr(0015)        # Console: end of line

RPC_query    = chr(0) * 8       # client_handle = 0, function code = RPC_FUNC_GET_VERSION
RPC_reply    = chr(0) * 12      # opcode = RPC_FUNC_GET_VERSION, client_handle = 0, valret = HAL_OK

# This is the query string we send to each USB port we find.  It's
# intended to be relatively harmless, at least for either of the HSM
# ports: the final Control-U should prevent the console from trying to
# interpret the RPC command, and the SLIP_END markers should cause
# the RPC server to treat the ASCII control characters as noise.
#
# Yes, this is a total kludge.  Useful identifiers for the USB ports
# are are on the wish list for a future revision of the hardware, but
# for the moment, we do what we can with what we have.

probe_string = SLIP_END + Control_U + SLIP_END + RPC_query + SLIP_END + Control_U + Control_M

def looks_like_console(response):
    # Check whether we got a known console prompt.
    return any(prompt in response for prompt in ("Username:", "Password:", "cryptech>"))


def looks_like_rpc(response):
    # Check whether we got something that looks like the response to an RPC version query.
    # We skip over the version value itself, as it might change, but we check that it's
    # terminated properly.  This is fragile, and will need to handle SLIP decoding if
    # we ever bump one of the version fields up into the range where the SLIP control
    # characters live, but it will do for the moment.
    try:
        return response[response.index(SLIP_END + RPC_reply) + len(SLIP_END + RPC_reply) + 4] == SLIP_END
    except ValueError:
        return False
    except IndexError:
        return False


rpc_hints    = None

ports = dict((port, None)
             for port, desc, hwid in serial.tools.list_ports_posix.comports()
             if "VID:PID=0403:6014" in hwid)

if not ports:
    sys.exit("Couldn't find any likely USB ports")

if args.verbose:
    print "Candidate USB ports:", ", ".join(ports)

for port in ports:
    while True:
        try:
            ports[port] = serial.Serial(port, 921600, timeout=0.1)
            break
        except serial.SerialException:
            time.sleep(0.2)

for port in ports:
    # Do we really need to dole out characters one at a time here?
    # Dunno, but this works well enough.
    for c in probe_string:
        ports[port].write(c)
        time.sleep(0.1)

time.sleep(1)

for port in ports:
    s = ""
    while True:
        c = ports[port].read(1)
        if len(c) > 0:
            s += c
        else:
            break
    if args.verbose:
        print "Received from {}: {!r} ({})".format(port, s, ":".join("{:02x}".format(ord(c)) for c in s))
    if looks_like_console(s):
        print "{} looks like the Cryptech HSM console port".format(port)
    if looks_like_rpc(s):
        print "{} looks like the Cryptech HSM RPC port".format(port)