aboutsummaryrefslogtreecommitdiff
path: root/cryptech_backup
blob: 18441a3b10d83964f090f9596ff53de8a220e5fc (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
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
#!/usr/bin/env python

#    KEY SOURCE                            KEY BACKUP
#
#                                          Generate and export KEKEK:
#                                               hal_rpc_pkey_generate_rsa()
#                                               hal_rpc_pkey_get_public_key()
#
#   Load KEKEK public   <----------------  Export KEKEK public
#
#       hal_rpc_pkey_load()
#       hal_rpc_pkey_export()
#
#   Export PKCS #8 and KEK   ---------->   Load PKCS #8 and KEK, import key
#
#                                               hal_rpc_pkey_import()

import sys
import json
import uuid
import atexit
import getpass
import argparse

from cryptech.libhal import *

def main():

    parser = argparse.ArgumentParser(
        formatter_class = argparse.ArgumentDefaultsHelpFormatter,
        description = __doc__)
    subparsers = parser.add_subparsers(
        title = "Commands (use \"--help\" after command name for help with individual commands)",
        metavar = "")
    parser.add_argument(
        "-p", "--pin",
        help = "wheel PIN")

    subparser = defcmd(subparsers, cmd_setup)
    group = subparser.add_mutually_exclusive_group()
    group.add_argument(
        "-n", "--new", action = "store_true",
        help = "force creation of new KEKEK")
    group.add_argument(
        "-u", "--uuid",
        help = "UUID of existing KEKEK to use")
    subparser.add_argument(
        "-k", "--keylen", type = int, default = 2048,
        help = "length of new KEKEK if we need to create one")
    subparser.add_argument(
        "-o", "--output", type = argparse.FileType("w"), default = "-",
        help = "output file")

    subparser = defcmd(subparsers, cmd_export)
    subparser.add_argument(
        "-i", "--input", type = argparse.FileType("r"), default = "-",
        help = "input file")
    subparser.add_argument(
        "-o", "--output", type = argparse.FileType("w"), default = "-",
        help = "output file")

    subparser = defcmd(subparsers, cmd_import)
    subparser.add_argument(
        "-i", "--input", type = argparse.FileType("r"), default = "-",
        help = "input file")

    args = parser.parse_args()

    hsm = HSM()

    try:
        hsm.login(HAL_USER_WHEEL, args.pin or getpass.getpass("Wheel PIN: "))

    except HALError as e:
        sys.exit("Couldn't log into HSM: {}".format(e))

    try:
        sys.exit(args.func(args, hsm))

    finally:
        hsm.logout()


def defcmd(subparsers, func):
    assert func.__name__.startswith("cmd_")
    subparser = subparsers.add_parser(func.__name__[4:],
                                      description = func.__doc__,
                                      help = func.__doc__.strip().splitlines()[0])
    subparser.set_defaults(func = func)
    return subparser


def b64(bytes):
    return bytes.encode("base64").splitlines()

def b64join(lines):
    return "".join(lines).decode("base64")


def cmd_setup(args, hsm):
    """
    Set up backup HSM for subsequent import.
    Generates an RSA keypair with appropriate usage settings
    to use as a key-encryption-key-encryption-key (KEKEK), and
    writes the KEKEK to a JSON file for transfer to primary HSM.
    """

    result = {}

    uuids = []
    if args.uuid:
        uuids.append(args.uuid)
    elif not args.new:
        uuids.extend(hsm.pkey_match(
            type  = HAL_KEY_TYPE_RSA_PRIVATE,
            mask  = HAL_KEY_FLAG_USAGE_KEYENCIPHERMENT | HAL_KEY_FLAG_TOKEN,
            flags = HAL_KEY_FLAG_USAGE_KEYENCIPHERMENT | HAL_KEY_FLAG_TOKEN))

    for uuid in uuids:
        with hsm.pkey_open(uuid) as kekek:
            if kekek.key_type != HAL_KEY_TYPE_RSA_PRIVATE:
                sys.stderr.write("Key {} is not an RSA private key\n".format(uuid))
            elif (kekek.key_flags & HAL_KEY_FLAG_USAGE_KEYENCIPHERMENT) == 0:
                sys.stderr.write("Key {} does not allow key encipherment\n".format(uuid))
            else:
                result.update(kekek_uuid   = str(kekek.uuid),
                              kekek_pubkey = b64(kekek.public_key))
                break

    if not result and not args.uuid:
        with hsm.pkey_generate_rsa(
                keylen = args.keylen,
                flags = HAL_KEY_FLAG_USAGE_KEYENCIPHERMENT | HAL_KEY_FLAG_TOKEN) as kekek:
            result.update(kekek_uuid   = str(kekek.uuid),
                          kekek_pubkey = b64(kekek.public_key))
    if not result:
        sys.exit("Could not find suitable KEKEK")

    result.update(comment = "KEKEK public key")
    json.dump(result, args.output, indent = 4, sort_keys = True)


def key_flag_names(flags):
    names = dict(digitalsignature = HAL_KEY_FLAG_USAGE_DIGITALSIGNATURE,
                 keyencipherment  = HAL_KEY_FLAG_USAGE_KEYENCIPHERMENT,
                 dataencipherment = HAL_KEY_FLAG_USAGE_DATAENCIPHERMENT,
                 token            = HAL_KEY_FLAG_TOKEN,
                 public           = HAL_KEY_FLAG_PUBLIC,
                 exportable       = HAL_KEY_FLAG_EXPORTABLE)
    return ", ".join(sorted(k for k, v in names.iteritems() if (flags & v) != 0))


def cmd_export(args, hsm):
    """
    Export encrypted keys from primary HSM.
    Takes a JSON file containing KEKEK (generated by running this
    script's "setup" command against the backup HSM), installs that
    key on the primary HSM, and backs up keys encrypted to the KEKEK
    by writing them to another JSON file for transfer to the backup HSM.
    """

    db = json.load(args.input)

    result = []

    kekek = None
    try:
        kekek = hsm.pkey_load(der   = b64join(db["kekek_pubkey"]),
                              flags = HAL_KEY_FLAG_USAGE_KEYENCIPHERMENT)

        for uuid in hsm.pkey_match(mask  = HAL_KEY_FLAG_EXPORTABLE,
                                   flags = HAL_KEY_FLAG_EXPORTABLE):
            with hsm.pkey_open(uuid) as pkey:

                if pkey.key_type in (HAL_KEY_TYPE_RSA_PRIVATE, HAL_KEY_TYPE_EC_PRIVATE):
                    pkcs8, kek = kekek.export_pkey(pkey)
                    result.append(dict(
                        comment = "Encrypted private key",
                        pkcs8   = b64(pkcs8),
                        kek     = b64(kek),
                        uuid    = str(pkey.uuid),
                        flags   = pkey.key_flags))

                elif pkey.key_type in (HAL_KEY_TYPE_RSA_PUBLIC, HAL_KEY_TYPE_EC_PUBLIC):
                    result.append(dict(
                        comment = "Public key",
                        spki    = b64(pkey.public_key),
                        uuid    = str(pkey.uuid),
                        flags   = pkey.key_flags))

    finally:
        if kekek is not None:
            kekek.delete()

    db.update(comment = "Cryptech Alpha encrypted key backup",
              keys    = result)
    json.dump(db, args.output, indent = 4, sort_keys = True)


def cmd_import(args, hsm):
    """
    Import encrypted keys into backup HSM.
    Takes a JSON file containing a key backup (generated by running
    this script's "export" command against the primary HSM) and imports
    keys into the backup HSM.
    """

    db = json.load(args.input)
    with hsm.pkey_open(uuid.UUID(db["kekek_uuid"]).bytes) as kekek:
        for k in db["keys"]:
            pkcs8 = b64join(k.get("pkcs8", ""))
            spki  = b64join(k.get("spki",  ""))
            kek   = b64join(k.get("kek",   ""))
            flags =         k.get("flags",  0)
            if pkcs8 and kek:
                with kekek.import_pkey(pkcs8 = pkcs8, kek = kek, flags = flags) as pkey:
                    print "Imported {} as {}".format(k["uuid"], pkey.uuid)
            elif spki:
                with hsm.pkey_load(der = spki, flags = flags) as pkey:
                    print "Loaded {} as {}".format(k["uuid"], pkey.uuid)


if __name__ == "__main__":
    main()