imgtool.py
3.17 KB
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
#! /usr/bin/env python3
import argparse
from imgtool import keys
from imgtool import image
from imgtool import version
import sys
def gen_rsa2048(args):
keys.RSA2048.generate().export_private(args.key)
def gen_ecdsa_p256(args):
keys.ecdsa256p1.generate().export_private(args.key)
def gen_ecdsa_p224(args):
print("TODO: p-224 not yet implemented")
keygens = {
'rsa-2048': gen_rsa2048,
'ecdsa-p256': gen_ecdsa_p256,
'ecdsa-p224': gen_ecdsa_p224, }
def do_keygen(args):
if args.type not in keygens:
msg = "Unexpected key type: {}".format(args.type)
raise argparse.ArgumentTypeError(msg)
keygens[args.type](args)
def do_getpub(args):
key = keys.load(args.key)
key.emit_c()
def do_sign(args):
align = args.align
if args.rsa_pkcs1_15:
keys.sign_rsa_pss = False
img = image.Image.load(args.infile, version=args.version,
header_size=args.header_size,
included_header=args.included_header,
pad=args.pad)
key = keys.load(args.key) if args.key else None
img.sign(key)
if args.pad:
img.pad_to(args.pad, args.align)
img.save(args.outfile)
subcmds = {
'keygen': do_keygen,
'getpub': do_getpub,
'sign': do_sign, }
def alignment_value(text):
value = int(text)
if value not in [1, 2, 4, 8]:
msg = "{} must be one of 1, 2, 4 or 8".format(value)
raise argparse.ArgumentTypeError(msg)
return value
def intparse(text):
"""Parse a command line argument as an integer.
Accepts 0x and other prefixes to allow other bases to be used."""
return int(text, 0)
def args():
parser = argparse.ArgumentParser()
subs = parser.add_subparsers(help='subcommand help', dest='subcmd')
keygenp = subs.add_parser('keygen', help='Generate pub/private keypair')
keygenp.add_argument('-k', '--key', metavar='filename', required=True)
keygenp.add_argument('-t', '--type', metavar='type',
choices=['rsa-2048', 'ecdsa-p224', 'ecdsa-p256'],
required=True)
getpub = subs.add_parser('getpub', help='Get public key from keypair')
getpub.add_argument('-k', '--key', metavar='filename', required=True)
sign = subs.add_parser('sign', help='Sign an image with a private key')
sign.add_argument('-k', '--key', metavar='filename')
sign.add_argument("--align", type=alignment_value, required=True)
sign.add_argument("-v", "--version", type=version.decode_version, required=True)
sign.add_argument("-H", "--header-size", type=intparse, required=True)
sign.add_argument("--included-header", default=False, action='store_true',
help='Image has gap for header')
sign.add_argument("--pad", type=intparse,
help='Pad image to this many bytes, adding trailer magic')
sign.add_argument("--rsa-pkcs1-15", help='Use old PKCS#1 v1.5 signature algorithm',
default=False, action='store_true')
sign.add_argument("infile")
sign.add_argument("outfile")
args = parser.parse_args()
if args.subcmd is None:
print('Must specify a subcommand', file=sys.stderr)
sys.exit(1)
subcmds[args.subcmd](args)
if __name__ == '__main__':
args()