| #!/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($signature), "\n"; |
| print "Size of information : ", length($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; |
| } |