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Commit b37d1bfb55d4b8a7d234fad0a84dca3336cee50b

Authored by David Howells
Committed by Linus Torvalds
1 parent 9e7814404b
Exists in smarc-l5.0.0_1.0.0-ga and in 5 other branches imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga

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>

Showing 3 changed files with 400 additions and 347 deletions Side-by-side Diff

... ... @@ -723,7 +723,7 @@
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
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   - 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 + );
32 38  
  39 +if (-r ".config") {
  40 + open(FD, "<.config") || die ".config";
  41 + while (<FD>) {
  42 + if ($_ =~ /^(CONFIG_.*)=[ym]/) {
  43 + $config{$1} = 1;
  44 + }
  45 + }
  46 + close(FD);
  47 +}
  48 +
33 49 #
  50 +# Function to read the contents of a file into a variable.
  51 +#
  52 +sub read_file($)
  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 +###############################################################################
  313 +
  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)) . $signature,
90 387  
  388 +waitpid($pid, 0) || die;
  389 +die "openssl rsautl died: $?" if ($? >> 8);
  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 +}
scripts/x509keyid
View file @ b37d1bf
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   -}