tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
MODSIGN: perlify sign-file and merge in x509keyid
Turn sign-file into perl and merge in x509keyid. The latter doesn't
need to be a separate script as it doesn't actually need to work out the
SHA1 sum of the X.509 certificate itself, since it can get that from the
X.509 certificate.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
authored by
David Howells
and committed by
Linus Torvalds
b37d1bfb
9e781440
+399
-346
+1
-1
Makefile
+1
-1
Makefile
···
723
723
MODSECKEY = ./signing_key.priv
724
724
MODPUBKEY = ./signing_key.x509
725
725
export MODPUBKEY
726
-
mod_sign_cmd = sh $(srctree)/scripts/sign-file $(MODSECKEY) $(MODPUBKEY) $(srctree)/scripts/x509keyid
726
+
mod_sign_cmd = perl $(srctree)/scripts/sign-file $(MODSECKEY) $(MODPUBKEY)
727
727
else
728
728
mod_sign_cmd = true
729
729
endif
+398
-77
scripts/sign-file
+398
-77
scripts/sign-file
···
1
-
#!/bin/bash
1
+
#!/usr/bin/perl -w
2
2
#
3
3
# Sign a module file using the given key.
4
4
#
5
-
# Format: sign-file <key> <x509> <keyid-script> <module>
5
+
# Format:
6
6
#
7
+
# ./scripts/sign-file [-v] <key> <x509> <module> [<dest>]
8
+
#
9
+
#
10
+
use strict;
11
+
use FileHandle;
12
+
use IPC::Open2;
7
13
8
-
scripts=`dirname $0`
14
+
my $verbose = 0;
15
+
if ($#ARGV >= 0 && $ARGV[0] eq "-v") {
16
+
$verbose = 1;
17
+
shift;
18
+
}
9
19
10
-
CONFIG_MODULE_SIG_SHA512=y
11
-
if [ -r .config ]
12
-
then
13
-
. ./.config
14
-
fi
20
+
die "Format: ./scripts/sign-file [-v] <key> <x509> <module> [<dest>]\n"
21
+
if ($#ARGV != 2 && $#ARGV != 3);
15
22
16
-
key="$1"
17
-
x509="$2"
18
-
keyid_script="$3"
19
-
mod="$4"
23
+
my $private_key = $ARGV[0];
24
+
my $x509 = $ARGV[1];
25
+
my $module = $ARGV[2];
26
+
my $dest = ($#ARGV == 3) ? $ARGV[3] : $ARGV[2] . "~";
20
27
21
-
if [ ! -r "$key" ]
22
-
then
23
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echo "Can't read private key" >&2
24
-
exit 2
25
-
fi
28
+
die "Can't read private key\n" unless (-r $private_key);
29
+
die "Can't read X.509 certificate\n" unless (-r $x509);
30
+
die "Can't read module\n" unless (-r $module);
26
31
27
-
if [ ! -r "$x509" ]
28
-
then
29
-
echo "Can't read X.509 certificate" >&2
30
-
exit 2
31
-
fi
32
+
#
33
+
# Read the kernel configuration
34
+
#
35
+
my %config = (
36
+
CONFIG_MODULE_SIG_SHA512 => 1
37
+
);
38
+
39
+
if (-r ".config") {
40
+
open(FD, "<.config") || die ".config";
41
+
while (<FD>) {
42
+
if ($_ =~ /^(CONFIG_.*)=[ym]/) {
43
+
$config{$1} = 1;
44
+
}
45
+
}
46
+
close(FD);
47
+
}
48
+
49
+
#
50
+
# Function to read the contents of a file into a variable.
51
+
#
52
+
sub read_file($)
53
+
{
54
+
my ($file) = @_;
55
+
my $contents;
56
+
my $len;
57
+
58
+
open(FD, "<$file") || die $file;
59
+
binmode FD;
60
+
my @st = stat(FD);
61
+
die $file if (!@st);
62
+
$len = read(FD, $contents, $st[7]) || die $file;
63
+
close(FD) || die $file;
64
+
die "$file: Wanted length ", $st[7], ", got ", $len, "\n"
65
+
if ($len != $st[7]);
66
+
return $contents;
67
+
}
68
+
69
+
###############################################################################
70
+
#
71
+
# First of all, we have to parse the X.509 certificate to find certain details
72
+
# about it.
73
+
#
74
+
# We read the DER-encoded X509 certificate and parse it to extract the Subject
75
+
# name and Subject Key Identifier. Theis provides the data we need to build
76
+
# the certificate identifier.
77
+
#
78
+
# The signer's name part of the identifier is fabricated from the commonName,
79
+
# the organizationName or the emailAddress components of the X.509 subject
80
+
# name.
81
+
#
82
+
# The subject key ID is used to select which of that signer's certificates
83
+
# we're intending to use to sign the module.
84
+
#
85
+
###############################################################################
86
+
my $x509_certificate = read_file($x509);
87
+
88
+
my $UNIV = 0 << 6;
89
+
my $APPL = 1 << 6;
90
+
my $CONT = 2 << 6;
91
+
my $PRIV = 3 << 6;
92
+
93
+
my $CONS = 0x20;
94
+
95
+
my $BOOLEAN = 0x01;
96
+
my $INTEGER = 0x02;
97
+
my $BIT_STRING = 0x03;
98
+
my $OCTET_STRING = 0x04;
99
+
my $NULL = 0x05;
100
+
my $OBJ_ID = 0x06;
101
+
my $UTF8String = 0x0c;
102
+
my $SEQUENCE = 0x10;
103
+
my $SET = 0x11;
104
+
my $UTCTime = 0x17;
105
+
my $GeneralizedTime = 0x18;
106
+
107
+
my %OIDs = (
108
+
pack("CCC", 85, 4, 3) => "commonName",
109
+
pack("CCC", 85, 4, 6) => "countryName",
110
+
pack("CCC", 85, 4, 10) => "organizationName",
111
+
pack("CCC", 85, 4, 11) => "organizationUnitName",
112
+
pack("CCCCCCCCC", 42, 134, 72, 134, 247, 13, 1, 1, 1) => "rsaEncryption",
113
+
pack("CCCCCCCCC", 42, 134, 72, 134, 247, 13, 1, 1, 5) => "sha1WithRSAEncryption",
114
+
pack("CCCCCCCCC", 42, 134, 72, 134, 247, 13, 1, 9, 1) => "emailAddress",
115
+
pack("CCC", 85, 29, 35) => "authorityKeyIdentifier",
116
+
pack("CCC", 85, 29, 14) => "subjectKeyIdentifier",
117
+
pack("CCC", 85, 29, 19) => "basicConstraints"
118
+
);
119
+
120
+
###############################################################################
121
+
#
122
+
# Extract an ASN.1 element from a string and return information about it.
123
+
#
124
+
###############################################################################
125
+
sub asn1_extract($$@)
126
+
{
127
+
my ($cursor, $expected_tag, $optional) = @_;
128
+
129
+
return [ -1 ]
130
+
if ($cursor->[1] == 0 && $optional);
131
+
132
+
die $x509, ": ", $cursor->[0], ": ASN.1 data underrun (elem ", $cursor->[1], ")\n"
133
+
if ($cursor->[1] < 2);
134
+
135
+
my ($tag, $len) = unpack("CC", substr(${$cursor->[2]}, $cursor->[0], 2));
136
+
137
+
if ($expected_tag != -1 && $tag != $expected_tag) {
138
+
return [ -1 ]
139
+
if ($optional);
140
+
die $x509, ": ", $cursor->[0], ": ASN.1 unexpected tag (", $tag,
141
+
" not ", $expected_tag, ")\n";
142
+
}
143
+
144
+
$cursor->[0] += 2;
145
+
$cursor->[1] -= 2;
146
+
147
+
die $x509, ": ", $cursor->[0], ": ASN.1 long tag\n"
148
+
if (($tag & 0x1f) == 0x1f);
149
+
die $x509, ": ", $cursor->[0], ": ASN.1 indefinite length\n"
150
+
if ($len == 0x80);
151
+
152
+
if ($len > 0x80) {
153
+
my $l = $len - 0x80;
154
+
die $x509, ": ", $cursor->[0], ": ASN.1 data underrun (len len $l)\n"
155
+
if ($cursor->[1] < $l);
156
+
157
+
if ($l == 0x1) {
158
+
$len = unpack("C", substr(${$cursor->[2]}, $cursor->[0], 1));
159
+
} elsif ($l = 0x2) {
160
+
$len = unpack("n", substr(${$cursor->[2]}, $cursor->[0], 2));
161
+
} elsif ($l = 0x3) {
162
+
$len = unpack("C", substr(${$cursor->[2]}, $cursor->[0], 1)) << 16;
163
+
$len = unpack("n", substr(${$cursor->[2]}, $cursor->[0] + 1, 2));
164
+
} elsif ($l = 0x4) {
165
+
$len = unpack("N", substr(${$cursor->[2]}, $cursor->[0], 4));
166
+
} else {
167
+
die $x509, ": ", $cursor->[0], ": ASN.1 element too long (", $l, ")\n";
168
+
}
169
+
170
+
$cursor->[0] += $l;
171
+
$cursor->[1] -= $l;
172
+
}
173
+
174
+
die $x509, ": ", $cursor->[0], ": ASN.1 data underrun (", $len, ")\n"
175
+
if ($cursor->[1] < $len);
176
+
177
+
my $ret = [ $tag, [ $cursor->[0], $len, $cursor->[2] ] ];
178
+
$cursor->[0] += $len;
179
+
$cursor->[1] -= $len;
180
+
181
+
return $ret;
182
+
}
183
+
184
+
###############################################################################
185
+
#
186
+
# Retrieve the data referred to by a cursor
187
+
#
188
+
###############################################################################
189
+
sub asn1_retrieve($)
190
+
{
191
+
my ($cursor) = @_;
192
+
my ($offset, $len, $data) = @$cursor;
193
+
return substr($$data, $offset, $len);
194
+
}
195
+
196
+
###############################################################################
197
+
#
198
+
# Roughly parse the X.509 certificate
199
+
#
200
+
###############################################################################
201
+
my $cursor = [ 0, length($x509_certificate), \$x509_certificate ];
202
+
203
+
my $cert = asn1_extract($cursor, $UNIV | $CONS | $SEQUENCE);
204
+
my $tbs = asn1_extract($cert->[1], $UNIV | $CONS | $SEQUENCE);
205
+
my $version = asn1_extract($tbs->[1], $CONT | $CONS | 0, 1);
206
+
my $serial_number = asn1_extract($tbs->[1], $UNIV | $INTEGER);
207
+
my $sig_type = asn1_extract($tbs->[1], $UNIV | $CONS | $SEQUENCE);
208
+
my $issuer = asn1_extract($tbs->[1], $UNIV | $CONS | $SEQUENCE);
209
+
my $validity = asn1_extract($tbs->[1], $UNIV | $CONS | $SEQUENCE);
210
+
my $subject = asn1_extract($tbs->[1], $UNIV | $CONS | $SEQUENCE);
211
+
my $key = asn1_extract($tbs->[1], $UNIV | $CONS | $SEQUENCE);
212
+
my $issuer_uid = asn1_extract($tbs->[1], $CONT | $CONS | 1, 1);
213
+
my $subject_uid = asn1_extract($tbs->[1], $CONT | $CONS | 2, 1);
214
+
my $extension_list = asn1_extract($tbs->[1], $CONT | $CONS | 3, 1);
215
+
216
+
my $subject_key_id = ();
217
+
my $authority_key_id = ();
218
+
219
+
#
220
+
# Parse the extension list
221
+
#
222
+
if ($extension_list->[0] != -1) {
223
+
my $extensions = asn1_extract($extension_list->[1], $UNIV | $CONS | $SEQUENCE);
224
+
225
+
while ($extensions->[1]->[1] > 0) {
226
+
my $ext = asn1_extract($extensions->[1], $UNIV | $CONS | $SEQUENCE);
227
+
my $x_oid = asn1_extract($ext->[1], $UNIV | $OBJ_ID);
228
+
my $x_crit = asn1_extract($ext->[1], $UNIV | $BOOLEAN, 1);
229
+
my $x_val = asn1_extract($ext->[1], $UNIV | $OCTET_STRING);
230
+
231
+
my $raw_oid = asn1_retrieve($x_oid->[1]);
232
+
next if (!exists($OIDs{$raw_oid}));
233
+
my $x_type = $OIDs{$raw_oid};
234
+
235
+
my $raw_value = asn1_retrieve($x_val->[1]);
236
+
237
+
if ($x_type eq "subjectKeyIdentifier") {
238
+
my $vcursor = [ 0, length($raw_value), \$raw_value ];
239
+
240
+
$subject_key_id = asn1_extract($vcursor, $UNIV | $OCTET_STRING);
241
+
}
242
+
}
243
+
}
244
+
245
+
###############################################################################
246
+
#
247
+
# Determine what we're going to use as the signer's name. In order of
248
+
# preference, take one of: commonName, organizationName or emailAddress.
249
+
#
250
+
###############################################################################
251
+
my $org = "";
252
+
my $cn = "";
253
+
my $email = "";
254
+
255
+
while ($subject->[1]->[1] > 0) {
256
+
my $rdn = asn1_extract($subject->[1], $UNIV | $CONS | $SET);
257
+
my $attr = asn1_extract($rdn->[1], $UNIV | $CONS | $SEQUENCE);
258
+
my $n_oid = asn1_extract($attr->[1], $UNIV | $OBJ_ID);
259
+
my $n_val = asn1_extract($attr->[1], -1);
260
+
261
+
my $raw_oid = asn1_retrieve($n_oid->[1]);
262
+
next if (!exists($OIDs{$raw_oid}));
263
+
my $n_type = $OIDs{$raw_oid};
264
+
265
+
my $raw_value = asn1_retrieve($n_val->[1]);
266
+
267
+
if ($n_type eq "organizationName") {
268
+
$org = $raw_value;
269
+
} elsif ($n_type eq "commonName") {
270
+
$cn = $raw_value;
271
+
} elsif ($n_type eq "emailAddress") {
272
+
$email = $raw_value;
273
+
}
274
+
}
275
+
276
+
my $signers_name = $email;
277
+
278
+
if ($org && $cn) {
279
+
# Don't use the organizationName if the commonName repeats it
280
+
if (length($org) <= length($cn) &&
281
+
substr($cn, 0, length($org)) eq $org) {
282
+
$signers_name = $cn;
283
+
goto got_id_name;
284
+
}
285
+
286
+
# Or a signifcant chunk of it
287
+
if (length($org) >= 7 &&
288
+
length($cn) >= 7 &&
289
+
substr($cn, 0, 7) eq substr($org, 0, 7)) {
290
+
$signers_name = $cn;
291
+
goto got_id_name;
292
+
}
293
+
294
+
$signers_name = $org . ": " . $cn;
295
+
} elsif ($org) {
296
+
$signers_name = $org;
297
+
} elsif ($cn) {
298
+
$signers_name = $cn;
299
+
}
300
+
301
+
got_id_name:
302
+
303
+
die $x509, ": ", "X.509: Couldn't find the Subject Key Identifier extension\n"
304
+
if (!$subject_key_id);
305
+
306
+
my $key_identifier = asn1_retrieve($subject_key_id->[1]);
307
+
308
+
###############################################################################
309
+
#
310
+
# Create and attach the module signature
311
+
#
312
+
###############################################################################
32
313
33
314
#
34
315
# Signature parameters
35
316
#
36
-
algo=1 # Public-key crypto algorithm: RSA
37
-
hash= # Digest algorithm
38
-
id_type=1 # Identifier type: X.509
317
+
my $algo = 1; # Public-key crypto algorithm: RSA
318
+
my $hash = 0; # Digest algorithm
319
+
my $id_type = 1; # Identifier type: X.509
39
320
40
321
#
41
322
# Digest the data
42
323
#
43
-
dgst=
44
-
if [ "$CONFIG_MODULE_SIG_SHA1" = "y" ]
45
-
then
46
-
prologue="0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2B, 0x0E, 0x03, 0x02, 0x1A, 0x05, 0x00, 0x04, 0x14"
47
-
dgst=-sha1
48
-
hash=2
49
-
elif [ "$CONFIG_MODULE_SIG_SHA224" = "y" ]
50
-
then
51
-
prologue="0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04, 0x05, 0x00, 0x04, 0x1C"
52
-
dgst=-sha224
53
-
hash=7
54
-
elif [ "$CONFIG_MODULE_SIG_SHA256" = "y" ]
55
-
then
56
-
prologue="0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05, 0x00, 0x04, 0x20"
57
-
dgst=-sha256
58
-
hash=4
59
-
elif [ "$CONFIG_MODULE_SIG_SHA384" = "y" ]
60
-
then
61
-
prologue="0x30, 0x41, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02, 0x05, 0x00, 0x04, 0x30"
62
-
dgst=-sha384
63
-
hash=5
64
-
elif [ "$CONFIG_MODULE_SIG_SHA512" = "y" ]
65
-
then
66
-
prologue="0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, 0x05, 0x00, 0x04, 0x40"
67
-
dgst=-sha512
68
-
hash=6
69
-
else
70
-
echo "$0: Can't determine hash algorithm" >&2
71
-
exit 2
72
-
fi
324
+
my ($dgst, $prologue) = ();
325
+
if (exists $config{"CONFIG_MODULE_SIG_SHA1"}) {
326
+
$prologue = pack("C*",
327
+
0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
328
+
0x2B, 0x0E, 0x03, 0x02, 0x1A,
329
+
0x05, 0x00, 0x04, 0x14);
330
+
$dgst = "-sha1";
331
+
$hash = 2;
332
+
} elsif (exists $config{"CONFIG_MODULE_SIG_SHA224"}) {
333
+
$prologue = pack("C*",
334
+
0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09,
335
+
0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04,
336
+
0x05, 0x00, 0x04, 0x1C);
337
+
$dgst = "-sha224";
338
+
$hash = 7;
339
+
} elsif (exists $config{"CONFIG_MODULE_SIG_SHA256"}) {
340
+
$prologue = pack("C*",
341
+
0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
342
+
0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01,
343
+
0x05, 0x00, 0x04, 0x20);
344
+
$dgst = "-sha256";
345
+
$hash = 4;
346
+
} elsif (exists $config{"CONFIG_MODULE_SIG_SHA384"}) {
347
+
$prologue = pack("C*",
348
+
0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
349
+
0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02,
350
+
0x05, 0x00, 0x04, 0x30);
351
+
$dgst = "-sha384";
352
+
$hash = 5;
353
+
} elsif (exists $config{"CONFIG_MODULE_SIG_SHA512"}) {
354
+
$prologue = pack("C*",
355
+
0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
356
+
0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03,
357
+
0x05, 0x00, 0x04, 0x40);
358
+
$dgst = "-sha512";
359
+
$hash = 6;
360
+
} else {
361
+
die "Can't determine hash algorithm";
362
+
}
73
363
74
-
(
75
-
perl -e "binmode STDOUT; print pack(\"C*\", $prologue)" || exit $?
76
-
openssl dgst $dgst -binary $mod || exit $?
77
-
) >$mod.dig || exit $?
364
+
#
365
+
# Generate the digest and read from openssl's stdout
366
+
#
367
+
my $digest;
368
+
$digest = readpipe("openssl dgst $dgst -binary $module") || die "openssl dgst";
78
369
79
370
#
80
371
# Generate the binary signature, which will be just the integer that comprises
81
372
# the signature with no metadata attached.
82
373
#
83
-
openssl rsautl -sign -inkey $key -keyform PEM -in $mod.dig -out $mod.sig || exit $?
84
-
siglen=`stat -c %s $mod.sig`
374
+
my $pid;
375
+
$pid = open2(*read_from, *write_to,
376
+
"openssl rsautl -sign -inkey $private_key -keyform PEM") ||
377
+
die "openssl rsautl";
378
+
binmode write_to;
379
+
print write_to $prologue . $digest || die "pipe to openssl rsautl";
380
+
close(write_to) || die "pipe to openssl rsautl";
85
381
86
-
SIGNER="`perl $keyid_script $x509 signer-name`"
87
-
KEYID="`perl $keyid_script $x509 keyid`"
88
-
keyidlen=$(echo -n "$KEYID" | wc -c)
89
-
signerlen=$(echo -n "$SIGNER" | wc -c)
382
+
binmode read_from;
383
+
my $signature;
384
+
read(read_from, $signature, 4096) || die "pipe from openssl rsautl";
385
+
close(read_from) || die "pipe from openssl rsautl";
386
+
$signature = pack("n", length($signature)) . $signature,
387
+
388
+
waitpid($pid, 0) || die;
389
+
die "openssl rsautl died: $?" if ($? >> 8);
90
390
91
391
#
92
392
# Build the signed binary
93
393
#
94
-
(
95
-
cat $mod || exit $?
96
-
echo '~Module signature appended~' || exit $?
97
-
echo -n "$SIGNER" || exit $?
98
-
echo -n "$KEYID" || exit $?
394
+
my $unsigned_module = read_file($module);
99
395
100
-
# Preface each signature integer with a 2-byte BE length
101
-
perl -e "binmode STDOUT; print pack(\"n\", $siglen)" || exit $?
102
-
cat $mod.sig || exit $?
396
+
my $magic_number = "~Module signature appended~\n";
103
397
104
-
# Generate the information block
105
-
perl -e "binmode STDOUT; print pack(\"CCCCCxxxN\", $algo, $hash, $id_type, $signerlen, $keyidlen, $siglen + 2)" || exit $?
106
-
) >$mod~ || exit $?
398
+
my $info = pack("CCCCCxxxN",
399
+
$algo, $hash, $id_type,
400
+
length($signers_name),
401
+
length($key_identifier),
402
+
length($signature));
107
403
108
-
mv $mod~ $mod || exit $?
404
+
if ($verbose) {
405
+
print "Size of unsigned module: ", length($unsigned_module), "\n";
406
+
print "Size of magic number : ", length($magic_number), "\n";
407
+
print "Size of signer's name : ", length($signers_name), "\n";
408
+
print "Size of key identifier : ", length($key_identifier), "\n";
409
+
print "Size of signature : ", length($signature), "\n";
410
+
print "Size of informaton : ", length($info), "\n";
411
+
print "Signer's name : '", $signers_name, "'\n";
412
+
print "Digest : $dgst\n";
413
+
}
414
+
415
+
open(FD, ">$dest") || die $dest;
416
+
binmode FD;
417
+
print FD
418
+
$unsigned_module,
419
+
$magic_number,
420
+
$signers_name,
421
+
$key_identifier,
422
+
$signature,
423
+
$info
424
+
;
425
+
close FD || die $dest;
426
+
427
+
if ($#ARGV != 3) {
428
+
rename($dest, $module) || die $module;
429
+
}
-268
scripts/x509keyid
-268
scripts/x509keyid
···
1
-
#!/usr/bin/perl -w
2
-
#
3
-
# Generate an identifier from an X.509 certificate that can be placed in a
4
-
# module signature to indentify the key to use.
5
-
#
6
-
# Format:
7
-
#
8
-
# ./scripts/x509keyid <x509-cert> <signer's-name> <key-id>
9
-
#
10
-
# We read the DER-encoded X509 certificate and parse it to extract the Subject
11
-
# name and Subject Key Identifier. The provide the data we need to build the
12
-
# certificate identifier.
13
-
#
14
-
# The signer's name part of the identifier is fabricated from the commonName,
15
-
# the organizationName or the emailAddress components of the X.509 subject
16
-
# name and written to the second named file.
17
-
#
18
-
# The subject key ID to select which of that signer's certificates we're
19
-
# intending to use to sign the module is written to the third named file.
20
-
#
21
-
use strict;
22
-
23
-
my $raw_data;
24
-
25
-
die "Need a filename [keyid|signer-name]\n" if ($#ARGV != 1);
26
-
27
-
my $src = $ARGV[0];
28
-
29
-
open(FD, "<$src") || die $src;
30
-
binmode FD;
31
-
my @st = stat(FD);
32
-
die $src if (!@st);
33
-
read(FD, $raw_data, $st[7]) || die $src;
34
-
close(FD);
35
-
36
-
my $UNIV = 0 << 6;
37
-
my $APPL = 1 << 6;
38
-
my $CONT = 2 << 6;
39
-
my $PRIV = 3 << 6;
40
-
41
-
my $CONS = 0x20;
42
-
43
-
my $BOOLEAN = 0x01;
44
-
my $INTEGER = 0x02;
45
-
my $BIT_STRING = 0x03;
46
-
my $OCTET_STRING = 0x04;
47
-
my $NULL = 0x05;
48
-
my $OBJ_ID = 0x06;
49
-
my $UTF8String = 0x0c;
50
-
my $SEQUENCE = 0x10;
51
-
my $SET = 0x11;
52
-
my $UTCTime = 0x17;
53
-
my $GeneralizedTime = 0x18;
54
-
55
-
my %OIDs = (
56
-
pack("CCC", 85, 4, 3) => "commonName",
57
-
pack("CCC", 85, 4, 6) => "countryName",
58
-
pack("CCC", 85, 4, 10) => "organizationName",
59
-
pack("CCC", 85, 4, 11) => "organizationUnitName",
60
-
pack("CCCCCCCCC", 42, 134, 72, 134, 247, 13, 1, 1, 1) => "rsaEncryption",
61
-
pack("CCCCCCCCC", 42, 134, 72, 134, 247, 13, 1, 1, 5) => "sha1WithRSAEncryption",
62
-
pack("CCCCCCCCC", 42, 134, 72, 134, 247, 13, 1, 9, 1) => "emailAddress",
63
-
pack("CCC", 85, 29, 35) => "authorityKeyIdentifier",
64
-
pack("CCC", 85, 29, 14) => "subjectKeyIdentifier",
65
-
pack("CCC", 85, 29, 19) => "basicConstraints"
66
-
);
67
-
68
-
###############################################################################
69
-
#
70
-
# Extract an ASN.1 element from a string and return information about it.
71
-
#
72
-
###############################################################################
73
-
sub asn1_extract($$@)
74
-
{
75
-
my ($cursor, $expected_tag, $optional) = @_;
76
-
77
-
return [ -1 ]
78
-
if ($cursor->[1] == 0 && $optional);
79
-
80
-
die $src, ": ", $cursor->[0], ": ASN.1 data underrun (elem ", $cursor->[1], ")\n"
81
-
if ($cursor->[1] < 2);
82
-
83
-
my ($tag, $len) = unpack("CC", substr(${$cursor->[2]}, $cursor->[0], 2));
84
-
85
-
if ($expected_tag != -1 && $tag != $expected_tag) {
86
-
return [ -1 ]
87
-
if ($optional);
88
-
die $src, ": ", $cursor->[0], ": ASN.1 unexpected tag (", $tag,
89
-
" not ", $expected_tag, ")\n";
90
-
}
91
-
92
-
$cursor->[0] += 2;
93
-
$cursor->[1] -= 2;
94
-
95
-
die $src, ": ", $cursor->[0], ": ASN.1 long tag\n"
96
-
if (($tag & 0x1f) == 0x1f);
97
-
die $src, ": ", $cursor->[0], ": ASN.1 indefinite length\n"
98
-
if ($len == 0x80);
99
-
100
-
if ($len > 0x80) {
101
-
my $l = $len - 0x80;
102
-
die $src, ": ", $cursor->[0], ": ASN.1 data underrun (len len $l)\n"
103
-
if ($cursor->[1] < $l);
104
-
105
-
if ($l == 0x1) {
106
-
$len = unpack("C", substr(${$cursor->[2]}, $cursor->[0], 1));
107
-
} elsif ($l = 0x2) {
108
-
$len = unpack("n", substr(${$cursor->[2]}, $cursor->[0], 2));
109
-
} elsif ($l = 0x3) {
110
-
$len = unpack("C", substr(${$cursor->[2]}, $cursor->[0], 1)) << 16;
111
-
$len = unpack("n", substr(${$cursor->[2]}, $cursor->[0] + 1, 2));
112
-
} elsif ($l = 0x4) {
113
-
$len = unpack("N", substr(${$cursor->[2]}, $cursor->[0], 4));
114
-
} else {
115
-
die $src, ": ", $cursor->[0], ": ASN.1 element too long (", $l, ")\n";
116
-
}
117
-
118
-
$cursor->[0] += $l;
119
-
$cursor->[1] -= $l;
120
-
}
121
-
122
-
die $src, ": ", $cursor->[0], ": ASN.1 data underrun (", $len, ")\n"
123
-
if ($cursor->[1] < $len);
124
-
125
-
my $ret = [ $tag, [ $cursor->[0], $len, $cursor->[2] ] ];
126
-
$cursor->[0] += $len;
127
-
$cursor->[1] -= $len;
128
-
129
-
return $ret;
130
-
}
131
-
132
-
###############################################################################
133
-
#
134
-
# Retrieve the data referred to by a cursor
135
-
#
136
-
###############################################################################
137
-
sub asn1_retrieve($)
138
-
{
139
-
my ($cursor) = @_;
140
-
my ($offset, $len, $data) = @$cursor;
141
-
return substr($$data, $offset, $len);
142
-
}
143
-
144
-
###############################################################################
145
-
#
146
-
# Roughly parse the X.509 certificate
147
-
#
148
-
###############################################################################
149
-
my $cursor = [ 0, length($raw_data), \$raw_data ];
150
-
151
-
my $cert = asn1_extract($cursor, $UNIV | $CONS | $SEQUENCE);
152
-
my $tbs = asn1_extract($cert->[1], $UNIV | $CONS | $SEQUENCE);
153
-
my $version = asn1_extract($tbs->[1], $CONT | $CONS | 0, 1);
154
-
my $serial_number = asn1_extract($tbs->[1], $UNIV | $INTEGER);
155
-
my $sig_type = asn1_extract($tbs->[1], $UNIV | $CONS | $SEQUENCE);
156
-
my $issuer = asn1_extract($tbs->[1], $UNIV | $CONS | $SEQUENCE);
157
-
my $validity = asn1_extract($tbs->[1], $UNIV | $CONS | $SEQUENCE);
158
-
my $subject = asn1_extract($tbs->[1], $UNIV | $CONS | $SEQUENCE);
159
-
my $key = asn1_extract($tbs->[1], $UNIV | $CONS | $SEQUENCE);
160
-
my $issuer_uid = asn1_extract($tbs->[1], $CONT | $CONS | 1, 1);
161
-
my $subject_uid = asn1_extract($tbs->[1], $CONT | $CONS | 2, 1);
162
-
my $extension_list = asn1_extract($tbs->[1], $CONT | $CONS | 3, 1);
163
-
164
-
my $subject_key_id = ();
165
-
my $authority_key_id = ();
166
-
167
-
#
168
-
# Parse the extension list
169
-
#
170
-
if ($extension_list->[0] != -1) {
171
-
my $extensions = asn1_extract($extension_list->[1], $UNIV | $CONS | $SEQUENCE);
172
-
173
-
while ($extensions->[1]->[1] > 0) {
174
-
my $ext = asn1_extract($extensions->[1], $UNIV | $CONS | $SEQUENCE);
175
-
my $x_oid = asn1_extract($ext->[1], $UNIV | $OBJ_ID);
176
-
my $x_crit = asn1_extract($ext->[1], $UNIV | $BOOLEAN, 1);
177
-
my $x_val = asn1_extract($ext->[1], $UNIV | $OCTET_STRING);
178
-
179
-
my $raw_oid = asn1_retrieve($x_oid->[1]);
180
-
next if (!exists($OIDs{$raw_oid}));
181
-
my $x_type = $OIDs{$raw_oid};
182
-
183
-
my $raw_value = asn1_retrieve($x_val->[1]);
184
-
185
-
if ($x_type eq "subjectKeyIdentifier") {
186
-
my $vcursor = [ 0, length($raw_value), \$raw_value ];
187
-
188
-
$subject_key_id = asn1_extract($vcursor, $UNIV | $OCTET_STRING);
189
-
}
190
-
}
191
-
}
192
-
193
-
###############################################################################
194
-
#
195
-
# Determine what we're going to use as the signer's name. In order of
196
-
# preference, take one of: commonName, organizationName or emailAddress.
197
-
#
198
-
###############################################################################
199
-
my $org = "";
200
-
my $cn = "";
201
-
my $email = "";
202
-
203
-
while ($subject->[1]->[1] > 0) {
204
-
my $rdn = asn1_extract($subject->[1], $UNIV | $CONS | $SET);
205
-
my $attr = asn1_extract($rdn->[1], $UNIV | $CONS | $SEQUENCE);
206
-
my $n_oid = asn1_extract($attr->[1], $UNIV | $OBJ_ID);
207
-
my $n_val = asn1_extract($attr->[1], -1);
208
-
209
-
my $raw_oid = asn1_retrieve($n_oid->[1]);
210
-
next if (!exists($OIDs{$raw_oid}));
211
-
my $n_type = $OIDs{$raw_oid};
212
-
213
-
my $raw_value = asn1_retrieve($n_val->[1]);
214
-
215
-
if ($n_type eq "organizationName") {
216
-
$org = $raw_value;
217
-
} elsif ($n_type eq "commonName") {
218
-
$cn = $raw_value;
219
-
} elsif ($n_type eq "emailAddress") {
220
-
$email = $raw_value;
221
-
}
222
-
}
223
-
224
-
my $id_name = $email;
225
-
226
-
if ($org && $cn) {
227
-
# Don't use the organizationName if the commonName repeats it
228
-
if (length($org) <= length($cn) &&
229
-
substr($cn, 0, length($org)) eq $org) {
230
-
$id_name = $cn;
231
-
goto got_id_name;
232
-
}
233
-
234
-
# Or a signifcant chunk of it
235
-
if (length($org) >= 7 &&
236
-
length($cn) >= 7 &&
237
-
substr($cn, 0, 7) eq substr($org, 0, 7)) {
238
-
$id_name = $cn;
239
-
goto got_id_name;
240
-
}
241
-
242
-
$id_name = $org . ": " . $cn;
243
-
} elsif ($org) {
244
-
$id_name = $org;
245
-
} elsif ($cn) {
246
-
$id_name = $cn;
247
-
}
248
-
249
-
got_id_name:
250
-
251
-
###############################################################################
252
-
#
253
-
# Output the signer's name and the key identifier that we're going to include
254
-
# in module signatures.
255
-
#
256
-
###############################################################################
257
-
die $src, ": ", "X.509: Couldn't find the Subject Key Identifier extension\n"
258
-
if (!$subject_key_id);
259
-
260
-
my $id_key_id = asn1_retrieve($subject_key_id->[1]);
261
-
262
-
if ($ARGV[1] eq "signer-name") {
263
-
print $id_name;
264
-
} elsif ($ARGV[1] eq "keyid") {
265
-
print $id_key_id;
266
-
} else {
267
-
die "Unknown arg";
268
-
}