/usr/bin/yhsm-decrypt-aead is in yhsm-tools 1.0.4l-1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 | #! /usr/bin/python
#
# Copyright (C) 2012-2013 Yubico AB. All rights reserved.
#
"""
This is a tool to decrypt AEADs generated using a YubiHSM, provided that
you know the key_handle used as well as the AES key used.
This can be used together with yhsm-generate-keys to generate a number
of AEADs, and then decrypt them to program YubiKeys accordingly.
"""
import os
import re
import sys
import fcntl
import argparse
import traceback
import pyhsm
args = None
yknum = 0
def parse_args():
"""
Parse the command line arguments
"""
parser = argparse.ArgumentParser(description = 'Decrypt AEADs',
add_help = True,
formatter_class = argparse.ArgumentDefaultsHelpFormatter,
)
parser.add_argument('-v', '--verbose',
dest='verbose',
action='store_true', default=False,
help='Enable verbose operation',
)
parser.add_argument('--debug',
dest='debug',
action='store_true', default=False,
help='Enable debug operation',
)
parser.add_argument('--format',
dest='format',
default='raw',
help='Select output format (aead, raw or yubikey-csv)',
)
parser.add_argument('--output-dir',
dest='output_dir',
help='Output dir basename (for --format aead)',
metavar='DIR',
)
parser.add_argument('--print-filename',
dest='print_filename',
action='store_true', default=False,
help='Prefix each row with the AEAD filename',
)
parser.add_argument('--key-handle',
dest='key_handle',
help='Key handle used when generating the AEADs.',
metavar='HANDLE',
)
parser.add_argument('--key-handle-out',
dest='key_handle_out',
help='Key handle used when generating *new* AEADs (with --format aead).',
metavar='HANDLE',
)
parser.add_argument('--aes-key',
dest='aes_key',
required=True,
help='AES key used when generating the AEADs.',
metavar='HEXSTR',
)
parser.add_argument('--aes-key-out',
dest='aes_key_out',
required=False,
help='AES key used when generating *new* AEADs (with --format aead).',
metavar='HEXSTR',
)
parser.add_argument('--start-public-id',
dest='start_id',
required=False, default=None,
help='The first public id to decrypt',
metavar='INT-OR-MODHEX',
)
parser.add_argument('--stop-public-id',
dest='stop_id',
required=False, default=None,
help='The last public id to decrypt',
metavar='INT-OR-MODHEX',
)
parser.add_argument('--fail-fast',
dest='fail_fast',
action='store_true', default=False,
help='Terminate on the first AEAD failure, rather than keep going.',
)
parser.add_argument('paths',
nargs='+',
help='Files and/or directories to process.',
metavar='FILE-OR-DIR'
)
args = parser.parse_args()
# argument fixups
args.format = args.format.lower()
args.aes_key = args.aes_key.decode('hex')
if args.key_handle:
args.key_handle = pyhsm.util.key_handle_to_int(args.key_handle)
if args.start_id is not None:
try:
n = int(args.start_id)
except ValueError:
hexstr = pyhsm.yubikey.modhex_decode(args.start_id)
n = int(hexstr, 16)
args.start_id = n
if args.stop_id is not None:
try:
n = int(args.stop_id)
except ValueError:
hexstr = pyhsm.yubikey.modhex_decode(args.stop_id)
n = int(hexstr, 16)
args.stop_id = n
# some checks
if args.format == 'aead':
if not args.output_dir:
sys.stderr.write("error: --output-dir is required when using --format aead.\n")
return False
if not os.path.isdir(args.output_dir):
sys.stderr.write("error: Output directory '%s' not found\n" % (args.output_dir))
return False
if not args.aes_key_out:
sys.stderr.write("error: --aes-key-out is required when using --format aead.\n")
return False
if not args.key_handle_out:
sys.stderr.write("error: --key-handle-out is required when using --format aead.\n")
return False
# argument fixups
args.aes_key_out = args.aes_key_out.decode('hex')
args.key_handle_out_orig = args.key_handle_out # save to use in AEAD output paths
args.key_handle_out = pyhsm.util.key_handle_to_int(args.key_handle_out)
return args
class MyState():
"""
Class to keep track of failed files.
"""
def __init__(self, args):
self.args = args
self.failed_files = []
self.file_count = 0
def log_failed(self, fn):
self.failed_files.append(fn)
self.file_count += 1
def log_success(self, fn):
self.file_count += 1
def should_quit(self):
return (self.failed_files and self.args.fail_fast)
def process_file(path, fn, args, state):
"""
The main function for reading a file and decrypting it.
"""
full_fn = os.path.join(path, fn)
if not re.match("^[cbdefghijklnrtuv]+$", fn):
if args.debug:
sys.stderr.write("warning: Ignoring non-modhex file '%s'\n" % (full_fn))
return True
if (args.start_id is not None) or (args.stop_id is not None):
this = int(pyhsm.yubikey.modhex_decode(fn), 16)
if (args.start_id is not None) and this < args.start_id:
if args.debug:
sys.stderr.write("warning: Skipping public id %s (%i) < %i\n" % (fn, this, args.start_id))
return True
if (args.stop_id is not None) and this > args.stop_id:
if args.debug:
sys.stderr.write("warning: Skipping public id %s (%i) > %i\n" % (fn, this, args.stop_id))
return True
if args.debug:
sys.stderr.write("Loading AEAD : %s\n" % full_fn)
aead = pyhsm.aead_cmd.YHSM_GeneratedAEAD(None, None, '')
aead.load(full_fn)
if not aead.nonce:
# AEAD file version 0, need to fill in nonce etc.
if args.key_handle is None:
sys.stderr.write("error: AEAD in file %s does not include key_handle, and none provided.\n" % (full_fn))
state.log_failed(full_fn)
return False
aead.key_handle = args.key_handle
aead.nonce = pyhsm.yubikey.modhex_decode(fn).decode('hex')
if args.debug:
sys.stderr.write("%s\n" % aead)
sys.stderr.write("AEAD len %i : %s\n" % (len(aead.data), aead.data.encode('hex')))
pt = pyhsm.soft_hsm.aesCCM(args.aes_key, aead.key_handle, aead.nonce, aead.data, decrypt = True)
if args.print_filename:
print("%s " % (full_fn)),
if args.format == 'raw':
print(pt.encode('hex'))
elif args.format == 'aead':
# encrypt secrets with new key
ct = pyhsm.soft_hsm.aesCCM(args.aes_key_out, args.key_handle_out, aead.nonce, pt, decrypt = False)
aead_out = pyhsm.aead_cmd.YHSM_GeneratedAEAD(aead.nonce, args.key_handle_out, ct)
filename = aead_filename(args.output_dir, args.key_handle_out_orig, fn)
aead_out.save(filename)
if args.print_filename:
print ""
elif args.format == 'yubikey-csv':
key = pt[:pyhsm.defines.KEY_SIZE]
uid = pt[pyhsm.defines.KEY_SIZE:]
access_code = '00' * 6
timestamp = ''
global yknum
yknum += 1
print("%i,%s,%s,%s,%s,%s,,,,," % (yknum,
fn,
uid.encode('hex'),
key.encode('hex'),
access_code,
timestamp,
))
state.log_success(full_fn)
return True
def aead_filename(aead_dir, key_handle, public_id):
"""
Return the filename of the AEAD for this public_id,
and create any missing directorys.
"""
parts = [aead_dir, key_handle] + pyhsm.util.group(public_id, 2)
path = os.path.join(*parts)
if not os.path.isdir(path):
os.makedirs(path)
return os.path.join(path, public_id)
def safe_process_files(path, files, args, state):
"""
Process a number of files in a directory. Catches any exception from the
processing and checks if we should fail directly or keep going.
"""
for fn in files:
full_fn = os.path.join(path, fn)
try:
if not process_file(path, fn, args, state):
return False
except Exception, e:
sys.stderr.write("error: %s\n%s\n" % (os.path.join(path, fn), traceback.format_exc()))
state.log_failed(full_fn)
if state.should_quit():
return False
return True
def walk_dir(path, args, state):
"""
Check all files in `path' to see if there is any requests that
we should send out on the bus.
"""
if args.debug:
sys.stderr.write("Walking %s\n" % path)
for root, _dirs, files in os.walk(path):
if not safe_process_files(root, files, args, state):
return False
if state.should_quit():
return False
return True
def main():
""" Main function when running as a program. """
global args
args = parse_args()
if not args:
return False
state = MyState(args)
for path in args.paths:
if os.path.isdir(path):
walk_dir(path, args, state)
else:
safe_process_files(os.path.dirname(path), [os.path.basename(path)], args, state)
if state.should_quit():
break
if state.failed_files:
sys.stderr.write("error: %i/%i AEADs failed\n" % (len(state.failed_files), state.file_count))
return False
if args.debug:
sys.stderr.write("Successfully processed %i AEADs\n" % (state.file_count))
return True
if __name__ == '__main__':
if main():
sys.exit(0)
sys.exit(1)
|