cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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build_OID_registry (4646B)


      1#!/usr/bin/perl -w
      2# SPDX-License-Identifier: GPL-2.0-or-later
      3#
      4# Build a static ASN.1 Object Identified (OID) registry
      5#
      6# Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
      7# Written by David Howells (dhowells@redhat.com)
      8#
      9
     10use strict;
     11
     12my @names = ();
     13my @oids = ();
     14
     15if ($#ARGV != 1) {
     16    print STDERR "Format: ", $0, " <in-h-file> <out-c-file>\n";
     17    exit(2);
     18}
     19
     20#
     21# Open the file to read from
     22#
     23open IN_FILE, "<$ARGV[0]" || die;
     24while (<IN_FILE>) {
     25    chomp;
     26    if (m!\s+OID_([a-zA-z][a-zA-Z0-9_]+),\s+/[*]\s+([012][.0-9]*)\s+[*]/!) {
     27	push @names, $1;
     28	push @oids, $2;
     29    }
     30}
     31close IN_FILE || die;
     32
     33#
     34# Open the files to write into
     35#
     36open C_FILE, ">$ARGV[1]" or die;
     37print C_FILE "/*\n";
     38print C_FILE " * Automatically generated by ", $0, ".  Do not edit\n";
     39print C_FILE " */\n";
     40
     41#
     42# Split the data up into separate lists and also determine the lengths of the
     43# encoded data arrays.
     44#
     45my @indices = ();
     46my @lengths = ();
     47my $total_length = 0;
     48
     49for (my $i = 0; $i <= $#names; $i++) {
     50    my $name = $names[$i];
     51    my $oid = $oids[$i];
     52
     53    my @components = split(/[.]/, $oid);
     54
     55    # Determine the encoded length of this OID
     56    my $size = $#components;
     57    for (my $loop = 2; $loop <= $#components; $loop++) {
     58	my $c = $components[$loop];
     59
     60	# We will base128 encode the number
     61	my $tmp = ($c == 0) ? 0 : int(log($c)/log(2));
     62	$tmp = int($tmp / 7);
     63	$size += $tmp;
     64    }
     65    push @lengths, $size;
     66    push @indices, $total_length;
     67    $total_length += $size;
     68}
     69
     70#
     71# Emit the look-up-by-OID index table
     72#
     73print C_FILE "\n";
     74if ($total_length <= 255) {
     75    print C_FILE "static const unsigned char oid_index[OID__NR + 1] = {\n";
     76} else {
     77    print C_FILE "static const unsigned short oid_index[OID__NR + 1] = {\n";
     78}
     79for (my $i = 0; $i <= $#names; $i++) {
     80    print C_FILE "\t[OID_", $names[$i], "] = ", $indices[$i], ",\n"
     81}
     82print C_FILE "\t[OID__NR] = ", $total_length, "\n";
     83print C_FILE "};\n";
     84
     85#
     86# Encode the OIDs
     87#
     88my @encoded_oids = ();
     89
     90for (my $i = 0; $i <= $#names; $i++) {
     91    my @octets = ();
     92
     93    my @components = split(/[.]/, $oids[$i]);
     94
     95    push @octets, $components[0] * 40 + $components[1];
     96
     97    for (my $loop = 2; $loop <= $#components; $loop++) {
     98	my $c = $components[$loop];
     99
    100	# Base128 encode the number
    101	my $tmp = ($c == 0) ? 0 : int(log($c)/log(2));
    102	$tmp = int($tmp / 7);
    103
    104	for (; $tmp > 0; $tmp--) {
    105	    push @octets, (($c >> $tmp * 7) & 0x7f) | 0x80;
    106	}
    107	push @octets, $c & 0x7f;
    108    }
    109
    110    push @encoded_oids, \@octets;
    111}
    112
    113#
    114# Create a hash value for each OID
    115#
    116my @hash_values = ();
    117for (my $i = 0; $i <= $#names; $i++) {
    118    my @octets = @{$encoded_oids[$i]};
    119
    120    my $hash = $#octets;
    121    foreach (@octets) {
    122	$hash += $_ * 33;
    123    }
    124
    125    $hash = ($hash >> 24) ^ ($hash >> 16) ^ ($hash >> 8) ^ ($hash);
    126
    127    push @hash_values, $hash & 0xff;
    128}
    129
    130#
    131# Emit the OID data
    132#
    133print C_FILE "\n";
    134print C_FILE "static const unsigned char oid_data[", $total_length, "] = {\n";
    135for (my $i = 0; $i <= $#names; $i++) {
    136    my @octets = @{$encoded_oids[$i]};
    137    print C_FILE "\t";
    138    print C_FILE $_, ", " foreach (@octets);
    139    print C_FILE "\t// ", $names[$i];
    140    print C_FILE "\n";
    141}
    142print C_FILE "};\n";
    143
    144#
    145# Build the search index table (ordered by length then hash then content)
    146#
    147my @index_table = ( 0 .. $#names );
    148
    149@index_table = sort {
    150    my @octets_a = @{$encoded_oids[$a]};
    151    my @octets_b = @{$encoded_oids[$b]};
    152
    153    return $hash_values[$a] <=> $hash_values[$b]
    154	if ($hash_values[$a] != $hash_values[$b]);
    155    return $#octets_a <=> $#octets_b
    156	if ($#octets_a != $#octets_b);
    157    for (my $i = $#octets_a; $i >= 0; $i--) {
    158	return $octets_a[$i] <=> $octets_b[$i]
    159	    if ($octets_a[$i] != $octets_b[$i]);
    160    }
    161    return 0;
    162
    163} @index_table;
    164
    165#
    166# Emit the search index and hash value table
    167#
    168print C_FILE "\n";
    169print C_FILE "static const struct {\n";
    170print C_FILE "\tunsigned char hash;\n";
    171if ($#names <= 255) {
    172    print C_FILE "\tenum OID oid : 8;\n";
    173} else {
    174    print C_FILE "\tenum OID oid : 16;\n";
    175}
    176print C_FILE "} oid_search_table[OID__NR] = {\n";
    177for (my $i = 0; $i <= $#names; $i++) {
    178    my @octets = @{$encoded_oids[$index_table[$i]]};
    179    printf(C_FILE "\t[%3u] = { %3u, OID_%-35s }, // ",
    180	   $i,
    181	   $hash_values[$index_table[$i]],
    182	   $names[$index_table[$i]]);
    183    printf C_FILE "%02x", $_ foreach (@octets);
    184    print C_FILE "\n";
    185}
    186print C_FILE "};\n";
    187
    188#
    189# Emit the OID debugging name table
    190#
    191#print C_FILE "\n";
    192#print C_FILE "const char *const oid_name_table[OID__NR + 1] = {\n";
    193#
    194#for (my $i = 0; $i <= $#names; $i++) {
    195#    print C_FILE "\t\"", $names[$i], "\",\n"
    196#}
    197#print C_FILE "\t\"Unknown-OID\"\n";
    198#print C_FILE "};\n";
    199
    200#
    201# Polish off
    202#
    203close C_FILE or die;