scripts/sign-file - arm/linux-arm64-legacy - Git at Google

 #!/usr/bin/perl -w
 #
 # Sign a module file using the given key.
 #

 my $USAGE =
 "Usage: scripts/sign-file [-v] <hash algo> <key> <x509> <module> [<dest>]\n" .
 "       scripts/sign-file [-v] -s <raw sig> <hash algo> <x509> <module> [<dest>]\n";

 use strict;
 use FileHandle;
 use IPC::Open2;
 use Getopt::Std;

 my %opts;
 getopts('vs:', \%opts) or die $USAGE;
 my $verbose = $opts{'v'};
 my $signature_file = $opts{'s'};

 die $USAGE if ($#ARGV > 4);
 die $USAGE if (!$signature_file && $#ARGV < 3 || $signature_file && $#ARGV < 2);

 my $dgst = shift @ARGV;
 my $private_key;
 if (!$signature_file) {
 	$private_key = shift @ARGV;
 }
 my $x509 = shift @ARGV;
 my $module = shift @ARGV;
 my ($dest, $keep_orig);
 if (@ARGV) {
 	$dest = $ARGV[0];
 	$keep_orig = 1;
 } else {
 	$dest = $module . "~";
 }

 die "Can't read private key\n" if (!$signature_file && !-r $private_key);
 die "Can't read signature file\n" if ($signature_file && !-r $signature_file);
 die "Can't read X.509 certificate\n" unless (-r $x509);
 die "Can't read module\n" unless (-r $module);

 #
 # Function to read the contents of a file into a variable.
 #
 sub read_file($)
 {
     my ($file) = @_;
     my $contents;
     my $len;

     open(FD, "<$file") || die $file;
     binmode FD;
     my @st = stat(FD);
     die $file if (!@st);
     $len = read(FD, $contents, $st[7]) || die $file;
     close(FD) || die $file;
     die "$file: Wanted length ", $st[7], ", got ", $len, "\n"
 	if ($len != $st[7]);
     return $contents;
 }

 ###############################################################################
 #
 # First of all, we have to parse the X.509 certificate to find certain details
 # about it.
 #
 # We read the DER-encoded X509 certificate and parse it to extract the Subject
 # name and Subject Key Identifier.  Theis provides the data we need to build
 # the certificate identifier.
 #
 # The signer's name part of the identifier is fabricated from the commonName,
 # the organizationName or the emailAddress components of the X.509 subject
 # name.
 #
 # The subject key ID is used to select which of that signer's certificates
 # we're intending to use to sign the module.
 #
 ###############################################################################
 my $x509_certificate = read_file($x509);

 my $UNIV = 0 << 6;
 my $APPL = 1 << 6;
 my $CONT = 2 << 6;
 my $PRIV = 3 << 6;

 my $CONS = 0x20;

 my $BOOLEAN	= 0x01;
 my $INTEGER	= 0x02;
 my $BIT_STRING	= 0x03;
 my $OCTET_STRING = 0x04;
 my $NULL	= 0x05;
 my $OBJ_ID	= 0x06;
 my $UTF8String	= 0x0c;
 my $SEQUENCE	= 0x10;
 my $SET		= 0x11;
 my $UTCTime	= 0x17;
 my $GeneralizedTime = 0x18;

 my %OIDs = (
     pack("CCC", 85, 4, 3)	=> "commonName",
     pack("CCC", 85, 4, 6)	=> "countryName",
     pack("CCC", 85, 4, 10)	=> "organizationName",
     pack("CCC", 85, 4, 11)	=> "organizationUnitName",
     pack("CCCCCCCCC", 42, 134, 72, 134, 247, 13, 1, 1, 1) => "rsaEncryption",
     pack("CCCCCCCCC", 42, 134, 72, 134, 247, 13, 1, 1, 5) => "sha1WithRSAEncryption",
     pack("CCCCCCCCC", 42, 134, 72, 134, 247, 13, 1, 9, 1) => "emailAddress",
     pack("CCC", 85, 29, 35)	=> "authorityKeyIdentifier",
     pack("CCC", 85, 29, 14)	=> "subjectKeyIdentifier",
     pack("CCC", 85, 29, 19)	=> "basicConstraints"
 );

 ###############################################################################
 #
 # Extract an ASN.1 element from a string and return information about it.
 #
 ###############################################################################
 sub asn1_extract($$@)
 {
     my ($cursor, $expected_tag, $optional) = @_;

     return [ -1 ]
 	if ($cursor->[1] == 0 && $optional);

     die $x509, ": ", $cursor->[0], ": ASN.1 data underrun (elem ", $cursor->[1], ")\n"
 	if ($cursor->[1] < 2);

     my ($tag, $len) = unpack("CC", substr(${$cursor->[2]}, $cursor->[0], 2));

     if ($expected_tag != -1 && $tag != $expected_tag) {
 	return [ -1 ]
 	    if ($optional);
 	die $x509, ": ", $cursor->[0], ": ASN.1 unexpected tag (", $tag,
 	" not ", $expected_tag, ")\n";
     }

     $cursor->[0] += 2;
     $cursor->[1] -= 2;

     die $x509, ": ", $cursor->[0], ": ASN.1 long tag\n"
 	if (($tag & 0x1f) == 0x1f);
     die $x509, ": ", $cursor->[0], ": ASN.1 indefinite length\n"
 	if ($len == 0x80);

     if ($len > 0x80) {
 	my $l = $len - 0x80;
 	die $x509, ": ", $cursor->[0], ": ASN.1 data underrun (len len $l)\n"
 	    if ($cursor->[1] < $l);

 	if ($l == 0x1) {
 	    $len = unpack("C", substr(${$cursor->[2]}, $cursor->[0], 1));
 	} elsif ($l == 0x2) {
 	    $len = unpack("n", substr(${$cursor->[2]}, $cursor->[0], 2));
 	} elsif ($l == 0x3) {
 	    $len = unpack("C", substr(${$cursor->[2]}, $cursor->[0], 1)) << 16;
 	    $len = unpack("n", substr(${$cursor->[2]}, $cursor->[0] + 1, 2));
 	} elsif ($l == 0x4) {
 	    $len = unpack("N", substr(${$cursor->[2]}, $cursor->[0], 4));
 	} else {
 	    die $x509, ": ", $cursor->[0], ": ASN.1 element too long (", $l, ")\n";
 	}

 	$cursor->[0] += $l;
 	$cursor->[1] -= $l;
     }

     die $x509, ": ", $cursor->[0], ": ASN.1 data underrun (", $len, ")\n"
 	if ($cursor->[1] < $len);

     my $ret = [ $tag, [ $cursor->[0], $len, $cursor->[2] ] ];
     $cursor->[0] += $len;
     $cursor->[1] -= $len;

     return $ret;
 }

 ###############################################################################
 #
 # Retrieve the data referred to by a cursor
 #
 ###############################################################################
 sub asn1_retrieve($)
 {
     my ($cursor) = @_;
     my ($offset, $len, $data) = @$cursor;
     return substr($$data, $offset, $len);
 }

 ###############################################################################
 #
 # Roughly parse the X.509 certificate
 #
 ###############################################################################
 my $cursor = [ 0, length($x509_certificate), \$x509_certificate ];

 my $cert = asn1_extract($cursor, $UNIV | $CONS | $SEQUENCE);
 my $tbs = asn1_extract($cert->[1], $UNIV | $CONS | $SEQUENCE);
 my $version = asn1_extract($tbs->[1], $CONT | $CONS | 0, 1);
 my $serial_number = asn1_extract($tbs->[1], $UNIV | $INTEGER);
 my $sig_type = asn1_extract($tbs->[1], $UNIV | $CONS | $SEQUENCE);
 my $issuer = asn1_extract($tbs->[1], $UNIV | $CONS | $SEQUENCE);
 my $validity = asn1_extract($tbs->[1], $UNIV | $CONS | $SEQUENCE);
 my $subject = asn1_extract($tbs->[1], $UNIV | $CONS | $SEQUENCE);
 my $key = asn1_extract($tbs->[1], $UNIV | $CONS | $SEQUENCE);
 my $issuer_uid = asn1_extract($tbs->[1], $CONT | $CONS | 1, 1);
 my $subject_uid = asn1_extract($tbs->[1], $CONT | $CONS | 2, 1);
 my $extension_list = asn1_extract($tbs->[1], $CONT | $CONS | 3, 1);

 my $subject_key_id = ();
 my $authority_key_id = ();

 #
 # Parse the extension list
 #
 if ($extension_list->[0] != -1) {
     my $extensions = asn1_extract($extension_list->[1], $UNIV | $CONS | $SEQUENCE);

     while ($extensions->[1]->[1] > 0) {
 	my $ext = asn1_extract($extensions->[1], $UNIV | $CONS | $SEQUENCE);
 	my $x_oid = asn1_extract($ext->[1], $UNIV | $OBJ_ID);
 	my $x_crit = asn1_extract($ext->[1], $UNIV | $BOOLEAN, 1);
 	my $x_val = asn1_extract($ext->[1], $UNIV | $OCTET_STRING);

 	my $raw_oid = asn1_retrieve($x_oid->[1]);
 	next if (!exists($OIDs{$raw_oid}));
 	my $x_type = $OIDs{$raw_oid};

 	my $raw_value = asn1_retrieve($x_val->[1]);

 	if ($x_type eq "subjectKeyIdentifier") {
 	    my $vcursor = [ 0, length($raw_value), \$raw_value ];

 	    $subject_key_id = asn1_extract($vcursor, $UNIV | $OCTET_STRING);
 	}
     }
 }

 ###############################################################################
 #
 # Determine what we're going to use as the signer's name.  In order of
 # preference, take one of: commonName, organizationName or emailAddress.
 #
 ###############################################################################
 my $org = "";
 my $cn = "";
 my $email = "";

 while ($subject->[1]->[1] > 0) {
     my $rdn = asn1_extract($subject->[1], $UNIV | $CONS | $SET);
     my $attr = asn1_extract($rdn->[1], $UNIV | $CONS | $SEQUENCE);
     my $n_oid = asn1_extract($attr->[1], $UNIV | $OBJ_ID);
     my $n_val = asn1_extract($attr->[1], -1);

     my $raw_oid = asn1_retrieve($n_oid->[1]);
     next if (!exists($OIDs{$raw_oid}));
     my $n_type = $OIDs{$raw_oid};

     my $raw_value = asn1_retrieve($n_val->[1]);

     if ($n_type eq "organizationName") {
 	$org = $raw_value;
     } elsif ($n_type eq "commonName") {
 	$cn = $raw_value;
     } elsif ($n_type eq "emailAddress") {
 	$email = $raw_value;
     }
 }

 my $signers_name = $email;

 if ($org && $cn) {
     # Don't use the organizationName if the commonName repeats it
     if (length($org) <= length($cn) &&
 	substr($cn, 0, length($org)) eq $org) {
 	$signers_name = $cn;
 	goto got_id_name;
     }

     # Or a signifcant chunk of it
     if (length($org) >= 7 &&
 	length($cn) >= 7 &&
 	substr($cn, 0, 7) eq substr($org, 0, 7)) {
 	$signers_name = $cn;
 	goto got_id_name;
     }

     $signers_name = $org . ": " . $cn;
 } elsif ($org) {
     $signers_name = $org;
 } elsif ($cn) {
     $signers_name = $cn;
 }

 got_id_name:

 die $x509, ": ", "X.509: Couldn't find the Subject Key Identifier extension\n"
     if (!$subject_key_id);

 my $key_identifier = asn1_retrieve($subject_key_id->[1]);

 ###############################################################################
 #
 # Create and attach the module signature
 #
 ###############################################################################

 #
 # Signature parameters
 #
 my $algo = 1;		# Public-key crypto algorithm: RSA
 my $hash = 0;		# Digest algorithm
 my $id_type = 1;	# Identifier type: X.509

 #
 # Digest the data
 #
 my $prologue;
 if ($dgst eq "sha1") {
     $prologue = pack("C*",
 		     0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
 		     0x2B, 0x0E, 0x03, 0x02, 0x1A,
 		     0x05, 0x00, 0x04, 0x14);
     $hash = 2;
 } elsif ($dgst eq "sha224") {
     $prologue = pack("C*",
 		     0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09,
 		     0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04,
 		     0x05, 0x00, 0x04, 0x1C);
     $hash = 7;
 } elsif ($dgst eq "sha256") {
     $prologue = pack("C*",
 		     0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
 		     0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01,
 		     0x05, 0x00, 0x04, 0x20);
     $hash = 4;
 } elsif ($dgst eq "sha384") {
     $prologue = pack("C*",
 		     0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
 		     0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02,
 		     0x05, 0x00, 0x04, 0x30);
     $hash = 5;
 } elsif ($dgst eq "sha512") {
     $prologue = pack("C*",
 		     0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
 		     0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03,
 		     0x05, 0x00, 0x04, 0x40);
     $hash = 6;
 } else {
     die "Unknown hash algorithm: $dgst\n";
 }

 my $signature;
 if ($signature_file) {
 	$signature = read_file($signature_file);
 } else {
 	#
 	# Generate the digest and read from openssl's stdout
 	#
 	my $digest;
 	$digest = readpipe("openssl dgst -$dgst -binary $module") || die "openssl dgst";

 	#
 	# Generate the binary signature, which will be just the integer that
 	# comprises the signature with no metadata attached.
 	#
 	my $pid;
 	$pid = open2(*read_from, *write_to,
 		     "openssl rsautl -sign -inkey $private_key -keyform PEM") ||
 	    die "openssl rsautl";
 	binmode write_to;
 	print write_to $prologue . $digest || die "pipe to openssl rsautl";
 	close(write_to) || die "pipe to openssl rsautl";

 	binmode read_from;
 	read(read_from, $signature, 4096) || die "pipe from openssl rsautl";
 	close(read_from) || die "pipe from openssl rsautl";
 	waitpid($pid, 0) || die;
 	die "openssl rsautl died: $?" if ($? >> 8);
 }
 $signature = pack("n", length($signature)) . $signature,

 #
 # Build the signed binary
 #
 my $unsigned_module = read_file($module);

 my $magic_number = "~Module signature appended~\n";

 my $info = pack("CCCCCxxxN",
 		$algo, $hash, $id_type,
 		length($signers_name),
 		length($key_identifier),
 		length($signature));

 if ($verbose) {
     print "Size of unsigned module: ", length($unsigned_module), "\n";
     print "Size of signer's name  : ", length($signers_name), "\n";
     print "Size of key identifier : ", length($key_identifier), "\n";
     print "Size of signature      : ", length($signature), "\n";
     print "Size of informaton     : ", length($info), "\n";
     print "Size of magic number   : ", length($magic_number), "\n";
     print "Signer's name          : '", $signers_name, "'\n";
     print "Digest                 : $dgst\n";
 }

 open(FD, ">$dest") || die $dest;
 binmode FD;
 print FD
     $unsigned_module,
     $signers_name,
     $key_identifier,
     $signature,
     $info,
     $magic_number
     ;
 close FD || die $dest;

 if (!$keep_orig) {
     rename($dest, $module) || die $module;
 }
	#!/usr/bin/perl -w
	#
	# Sign a module file using the given key.
	#

	my $USAGE =
	"Usage: scripts/sign-file [-v] <hash algo> <key> <x509> <module> [<dest>]\n" .
	" scripts/sign-file [-v] -s <raw sig> <hash algo> <x509> <module> [<dest>]\n";

	use strict;
	use FileHandle;
	use IPC::Open2;
	use Getopt::Std;

	my %opts;
	getopts('vs:', \%opts) or die $USAGE;
	my $verbose = $opts{'v'};
	my $signature_file = $opts{'s'};

	die $USAGE if ($#ARGV > 4);
	die $USAGE if (!$signature_file && $#ARGV < 3 \|\| $signature_file && $#ARGV < 2);

	my $dgst = shift @ARGV;
	my $private_key;
	if (!$signature_file) {
	$private_key = shift @ARGV;
	}
	my $x509 = shift @ARGV;
	my $module = shift @ARGV;
	my ($dest, $keep_orig);
	if (@ARGV) {
	$dest = $ARGV[0];
	$keep_orig = 1;
	} else {
	$dest = $module . "~";
	}

	die "Can't read private key\n" if (!$signature_file && !-r $private_key);
	die "Can't read signature file\n" if ($signature_file && !-r $signature_file);
	die "Can't read X.509 certificate\n" unless (-r $x509);
	die "Can't read module\n" unless (-r $module);

	#
	# Function to read the contents of a file into a variable.
	#
	sub read_file($)
	{
	my ($file) = @_;
	my $contents;
	my $len;

	open(FD, "<$file") \|\| die $file;
	binmode FD;
	my @st = stat(FD);
	die $file if (!@st);
	$len = read(FD, $contents, $st[7]) \|\| die $file;
	close(FD) \|\| die $file;
	die "$file: Wanted length ", $st[7], ", got ", $len, "\n"
	if ($len != $st[7]);
	return $contents;
	}

	###############################################################################
	#
	# First of all, we have to parse the X.509 certificate to find certain details
	# about it.
	#
	# We read the DER-encoded X509 certificate and parse it to extract the Subject
	# name and Subject Key Identifier. Theis provides the data we need to build
	# the certificate identifier.
	#
	# The signer's name part of the identifier is fabricated from the commonName,
	# the organizationName or the emailAddress components of the X.509 subject
	# name.
	#
	# The subject key ID is used to select which of that signer's certificates
	# we're intending to use to sign the module.
	#
	###############################################################################
	my $x509_certificate = read_file($x509);

	my $UNIV = 0 << 6;
	my $APPL = 1 << 6;
	my $CONT = 2 << 6;
	my $PRIV = 3 << 6;

	my $CONS = 0x20;

	my $BOOLEAN = 0x01;
	my $INTEGER = 0x02;
	my $BIT_STRING = 0x03;
	my $OCTET_STRING = 0x04;
	my $NULL = 0x05;
	my $OBJ_ID = 0x06;
	my $UTF8String = 0x0c;
	my $SEQUENCE = 0x10;
	my $SET = 0x11;
	my $UTCTime = 0x17;
	my $GeneralizedTime = 0x18;

	my %OIDs = (
	pack("CCC", 85, 4, 3) => "commonName",
	pack("CCC", 85, 4, 6) => "countryName",
	pack("CCC", 85, 4, 10) => "organizationName",
	pack("CCC", 85, 4, 11) => "organizationUnitName",
	pack("CCCCCCCCC", 42, 134, 72, 134, 247, 13, 1, 1, 1) => "rsaEncryption",
	pack("CCCCCCCCC", 42, 134, 72, 134, 247, 13, 1, 1, 5) => "sha1WithRSAEncryption",
	pack("CCCCCCCCC", 42, 134, 72, 134, 247, 13, 1, 9, 1) => "emailAddress",
	pack("CCC", 85, 29, 35) => "authorityKeyIdentifier",
	pack("CCC", 85, 29, 14) => "subjectKeyIdentifier",
	pack("CCC", 85, 29, 19) => "basicConstraints"
	);

	###############################################################################
	#
	# Extract an ASN.1 element from a string and return information about it.
	#
	###############################################################################
	sub asn1_extract($$@)
	{
	my ($cursor, $expected_tag, $optional) = @_;

	return [ -1 ]
	if ($cursor->[1] == 0 && $optional);

	die $x509, ": ", $cursor->[0], ": ASN.1 data underrun (elem ", $cursor->[1], ")\n"
	if ($cursor->[1] < 2);

	my ($tag, $len) = unpack("CC", substr(${$cursor->[2]}, $cursor->[0], 2));

	if ($expected_tag != -1 && $tag != $expected_tag) {
	return [ -1 ]
	if ($optional);
	die $x509, ": ", $cursor->[0], ": ASN.1 unexpected tag (", $tag,
	" not ", $expected_tag, ")\n";
	}

	$cursor->[0] += 2;
	$cursor->[1] -= 2;

	die $x509, ": ", $cursor->[0], ": ASN.1 long tag\n"
	if (($tag & 0x1f) == 0x1f);
	die $x509, ": ", $cursor->[0], ": ASN.1 indefinite length\n"
	if ($len == 0x80);

	if ($len > 0x80) {
	my $l = $len - 0x80;
	die $x509, ": ", $cursor->[0], ": ASN.1 data underrun (len len $l)\n"
	if ($cursor->[1] < $l);

	if ($l == 0x1) {
	$len = unpack("C", substr(${$cursor->[2]}, $cursor->[0], 1));
	} elsif ($l == 0x2) {
	$len = unpack("n", substr(${$cursor->[2]}, $cursor->[0], 2));
	} elsif ($l == 0x3) {
	$len = unpack("C", substr(${$cursor->[2]}, $cursor->[0], 1)) << 16;
	$len = unpack("n", substr(${$cursor->[2]}, $cursor->[0] + 1, 2));
	} elsif ($l == 0x4) {
	$len = unpack("N", substr(${$cursor->[2]}, $cursor->[0], 4));
	} else {
	die $x509, ": ", $cursor->[0], ": ASN.1 element too long (", $l, ")\n";
	}

	$cursor->[0] += $l;
	$cursor->[1] -= $l;
	}

	die $x509, ": ", $cursor->[0], ": ASN.1 data underrun (", $len, ")\n"
	if ($cursor->[1] < $len);

	my $ret = [ $tag, [ $cursor->[0], $len, $cursor->[2] ] ];
	$cursor->[0] += $len;
	$cursor->[1] -= $len;

	return $ret;
	}

	###############################################################################
	#
	# Retrieve the data referred to by a cursor
	#
	###############################################################################
	sub asn1_retrieve($)
	{
	my ($cursor) = @_;
	my ($offset, $len, $data) = @$cursor;
	return substr($$data, $offset, $len);
	}

	###############################################################################
	#
	# Roughly parse the X.509 certificate
	#
	###############################################################################
	my $cursor = [ 0, length($x509_certificate), \$x509_certificate ];

	my $cert = asn1_extract($cursor, $UNIV \| $CONS \| $SEQUENCE);
	my $tbs = asn1_extract($cert->[1], $UNIV \| $CONS \| $SEQUENCE);
	my $version = asn1_extract($tbs->[1], $CONT \| $CONS \| 0, 1);
	my $serial_number = asn1_extract($tbs->[1], $UNIV \| $INTEGER);
	my $sig_type = asn1_extract($tbs->[1], $UNIV \| $CONS \| $SEQUENCE);
	my $issuer = asn1_extract($tbs->[1], $UNIV \| $CONS \| $SEQUENCE);
	my $validity = asn1_extract($tbs->[1], $UNIV \| $CONS \| $SEQUENCE);
	my $subject = asn1_extract($tbs->[1], $UNIV \| $CONS \| $SEQUENCE);
	my $key = asn1_extract($tbs->[1], $UNIV \| $CONS \| $SEQUENCE);
	my $issuer_uid = asn1_extract($tbs->[1], $CONT \| $CONS \| 1, 1);
	my $subject_uid = asn1_extract($tbs->[1], $CONT \| $CONS \| 2, 1);
	my $extension_list = asn1_extract($tbs->[1], $CONT \| $CONS \| 3, 1);

	my $subject_key_id = ();
	my $authority_key_id = ();

	#
	# Parse the extension list
	#
	if ($extension_list->[0] != -1) {
	my $extensions = asn1_extract($extension_list->[1], $UNIV \| $CONS \| $SEQUENCE);

	while ($extensions->[1]->[1] > 0) {
	my $ext = asn1_extract($extensions->[1], $UNIV \| $CONS \| $SEQUENCE);
	my $x_oid = asn1_extract($ext->[1], $UNIV \| $OBJ_ID);
	my $x_crit = asn1_extract($ext->[1], $UNIV \| $BOOLEAN, 1);
	my $x_val = asn1_extract($ext->[1], $UNIV \| $OCTET_STRING);

	my $raw_oid = asn1_retrieve($x_oid->[1]);
	next if (!exists($OIDs{$raw_oid}));
	my $x_type = $OIDs{$raw_oid};

	my $raw_value = asn1_retrieve($x_val->[1]);

	if ($x_type eq "subjectKeyIdentifier") {
	my $vcursor = [ 0, length($raw_value), \$raw_value ];

	$subject_key_id = asn1_extract($vcursor, $UNIV \| $OCTET_STRING);
	}
	}
	}

	###############################################################################
	#
	# Determine what we're going to use as the signer's name. In order of
	# preference, take one of: commonName, organizationName or emailAddress.
	#
	###############################################################################
	my $org = "";
	my $cn = "";
	my $email = "";

	while ($subject->[1]->[1] > 0) {
	my $rdn = asn1_extract($subject->[1], $UNIV \| $CONS \| $SET);
	my $attr = asn1_extract($rdn->[1], $UNIV \| $CONS \| $SEQUENCE);
	my $n_oid = asn1_extract($attr->[1], $UNIV \| $OBJ_ID);
	my $n_val = asn1_extract($attr->[1], -1);

	my $raw_oid = asn1_retrieve($n_oid->[1]);
	next if (!exists($OIDs{$raw_oid}));
	my $n_type = $OIDs{$raw_oid};

	my $raw_value = asn1_retrieve($n_val->[1]);

	if ($n_type eq "organizationName") {
	$org = $raw_value;
	} elsif ($n_type eq "commonName") {
	$cn = $raw_value;
	} elsif ($n_type eq "emailAddress") {
	$email = $raw_value;
	}
	}

	my $signers_name = $email;

	if ($org && $cn) {
	# Don't use the organizationName if the commonName repeats it
	if (length($org) <= length($cn) &&
	substr($cn, 0, length($org)) eq $org) {
	$signers_name = $cn;
	goto got_id_name;
	}

	# Or a signifcant chunk of it
	if (length($org) >= 7 &&
	length($cn) >= 7 &&
	substr($cn, 0, 7) eq substr($org, 0, 7)) {
	$signers_name = $cn;
	goto got_id_name;
	}

	$signers_name = $org . ": " . $cn;
	} elsif ($org) {
	$signers_name = $org;
	} elsif ($cn) {
	$signers_name = $cn;
	}

	got_id_name:

	die $x509, ": ", "X.509: Couldn't find the Subject Key Identifier extension\n"
	if (!$subject_key_id);

	my $key_identifier = asn1_retrieve($subject_key_id->[1]);

	###############################################################################
	#
	# Create and attach the module signature
	#
	###############################################################################

	#
	# Signature parameters
	#
	my $algo = 1; # Public-key crypto algorithm: RSA
	my $hash = 0; # Digest algorithm
	my $id_type = 1; # Identifier type: X.509

	#
	# Digest the data
	#
	my $prologue;
	if ($dgst eq "sha1") {
	$prologue = pack("C*",
	0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
	0x2B, 0x0E, 0x03, 0x02, 0x1A,
	0x05, 0x00, 0x04, 0x14);
	$hash = 2;
	} elsif ($dgst eq "sha224") {
	$prologue = pack("C*",
	0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09,
	0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04,
	0x05, 0x00, 0x04, 0x1C);
	$hash = 7;
	} elsif ($dgst eq "sha256") {
	$prologue = pack("C*",
	0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
	0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01,
	0x05, 0x00, 0x04, 0x20);
	$hash = 4;
	} elsif ($dgst eq "sha384") {
	$prologue = pack("C*",
	0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
	0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02,
	0x05, 0x00, 0x04, 0x30);
	$hash = 5;
	} elsif ($dgst eq "sha512") {
	$prologue = pack("C*",
	0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
	0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03,
	0x05, 0x00, 0x04, 0x40);
	$hash = 6;
	} else {
	die "Unknown hash algorithm: $dgst\n";
	}

	my $signature;
	if ($signature_file) {
	$signature = read_file($signature_file);
	} else {
	#
	# Generate the digest and read from openssl's stdout
	#
	my $digest;
	$digest = readpipe("openssl dgst -$dgst -binary $module") \|\| die "openssl dgst";

	#
	# Generate the binary signature, which will be just the integer that
	# comprises the signature with no metadata attached.
	#
	my $pid;
	$pid = open2(read_from, write_to,
	"openssl rsautl -sign -inkey $private_key -keyform PEM") \|\|
	die "openssl rsautl";
	binmode write_to;
	print write_to $prologue . $digest \|\| die "pipe to openssl rsautl";
	close(write_to) \|\| die "pipe to openssl rsautl";

	binmode read_from;
	read(read_from, $signature, 4096) \|\| die "pipe from openssl rsautl";
	close(read_from) \|\| die "pipe from openssl rsautl";
	waitpid($pid, 0) \|\| die;
	die "openssl rsautl died: $?" if ($? >> 8);
	}
	$signature = pack("n", length($signature)) . $signature,

	#
	# Build the signed binary
	#
	my $unsigned_module = read_file($module);

	my $magic_number = "~Module signature appended~\n";

	my $info = pack("CCCCCxxxN",
	$algo, $hash, $id_type,
	length($signers_name),
	length($key_identifier),
	length($signature));

	if ($verbose) {
	print "Size of unsigned module: ", length($unsigned_module), "\n";
	print "Size of signer's name : ", length($signers_name), "\n";
	print "Size of key identifier : ", length($key_identifier), "\n";
	print "Size of signature : ", length($signature), "\n";
	print "Size of informaton : ", length($info), "\n";
	print "Size of magic number : ", length($magic_number), "\n";
	print "Signer's name : '", $signers_name, "'\n";
	print "Digest : $dgst\n";
	}

	open(FD, ">$dest") \|\| die $dest;
	binmode FD;
	print FD
	$unsigned_module,
	$signers_name,
	$key_identifier,
	$signature,
	$info,
	$magic_number
	;
	close FD \|\| die $dest;

	if (!$keep_orig) {
	rename($dest, $module) \|\| die $module;
	}