aboutsummaryrefslogtreecommitdiff
path: root/scripts/build_OID_registry
blob: d7fc32ea8ac224f0fb6f28c58b196c665e510992 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
#!/usr/bin/perl -w
# SPDX-License-Identifier: GPL-2.0-or-later
#
# Build a static ASN.1 Object Identified (OID) registry
#
# Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
# Written by David Howells (dhowells@redhat.com)
#

use strict;

my @names = ();
my @oids = ();

if ($#ARGV != 1) {
    print STDERR "Format: ", $0, " <in-h-file> <out-c-file>\n";
    exit(2);
}

#
# Open the file to read from
#
open IN_FILE, "<$ARGV[0]" || die;
while (<IN_FILE>) {
    chomp;
    if (m!\s+OID_([a-zA-z][a-zA-Z0-9_]+),\s+/[*]\s+([012][.0-9]*)\s+[*]/!) {
	push @names, $1;
	push @oids, $2;
    }
}
close IN_FILE || die;

#
# Open the files to write into
#
open C_FILE, ">$ARGV[1]" or die;
print C_FILE "/*\n";
print C_FILE " * Automatically generated by ", $0, ".  Do not edit\n";
print C_FILE " */\n";

#
# Split the data up into separate lists and also determine the lengths of the
# encoded data arrays.
#
my @indices = ();
my @lengths = ();
my $total_length = 0;

for (my $i = 0; $i <= $#names; $i++) {
    my $name = $names[$i];
    my $oid = $oids[$i];

    my @components = split(/[.]/, $oid);

    # Determine the encoded length of this OID
    my $size = $#components;
    for (my $loop = 2; $loop <= $#components; $loop++) {
	my $c = $components[$loop];

	# We will base128 encode the number
	my $tmp = ($c == 0) ? 0 : int(log($c)/log(2));
	$tmp = int($tmp / 7);
	$size += $tmp;
    }
    push @lengths, $size;
    push @indices, $total_length;
    $total_length += $size;
}

#
# Emit the look-up-by-OID index table
#
print C_FILE "\n";
if ($total_length <= 255) {
    print C_FILE "static const unsigned char oid_index[OID__NR + 1] = {\n";
} else {
    print C_FILE "static const unsigned short oid_index[OID__NR + 1] = {\n";
}
for (my $i = 0; $i <= $#names; $i++) {
    print C_FILE "\t[OID_", $names[$i], "] = ", $indices[$i], ",\n"
}
print C_FILE "\t[OID__NR] = ", $total_length, "\n";
print C_FILE "};\n";

#
# Encode the OIDs
#
my @encoded_oids = ();

for (my $i = 0; $i <= $#names; $i++) {
    my @octets = ();

    my @components = split(/[.]/, $oids[$i]);

    push @octets, $components[0] * 40 + $components[1];

    for (my $loop = 2; $loop <= $#components; $loop++) {
	my $c = $components[$loop];

	# Base128 encode the number
	my $tmp = ($c == 0) ? 0 : int(log($c)/log(2));
	$tmp = int($tmp / 7);

	for (; $tmp > 0; $tmp--) {
	    push @octets, (($c >> $tmp * 7) & 0x7f) | 0x80;
	}
	push @octets, $c & 0x7f;
    }

    push @encoded_oids, \@octets;
}

#
# Create a hash value for each OID
#
my @hash_values = ();
for (my $i = 0; $i <= $#names; $i++) {
    my @octets = @{$encoded_oids[$i]};

    my $hash = $#octets;
    foreach (@octets) {
	$hash += $_ * 33;
    }

    $hash = ($hash >> 24) ^ ($hash >> 16) ^ ($hash >> 8) ^ ($hash);

    push @hash_values, $hash & 0xff;
}

#
# Emit the OID data
#
print C_FILE "\n";
print C_FILE "static const unsigned char oid_data[", $total_length, "] = {\n";
for (my $i = 0; $i <= $#names; $i++) {
    my @octets = @{$encoded_oids[$i]};
    print C_FILE "\t";
    print C_FILE $_, ", " foreach (@octets);
    print C_FILE "\t// ", $names[$i];
    print C_FILE "\n";
}
print C_FILE "};\n";

#
# Build the search index table (ordered by length then hash then content)
#
my @index_table = ( 0 .. $#names );

@index_table = sort {
    my @octets_a = @{$encoded_oids[$a]};
    my @octets_b = @{$encoded_oids[$b]};

    return $hash_values[$a] <=> $hash_values[$b]
	if ($hash_values[$a] != $hash_values[$b]);
    return $#octets_a <=> $#octets_b
	if ($#octets_a != $#octets_b);
    for (my $i = $#octets_a; $i >= 0; $i--) {
	return $octets_a[$i] <=> $octets_b[$i]
	    if ($octets_a[$i] != $octets_b[$i]);
    }
    return 0;

} @index_table;

#
# Emit the search index and hash value table
#
print C_FILE "\n";
print C_FILE "static const struct {\n";
print C_FILE "\tunsigned char hash;\n";
if ($#names <= 255) {
    print C_FILE "\tenum OID oid : 8;\n";
} else {
    print C_FILE "\tenum OID oid : 16;\n";
}
print C_FILE "} oid_search_table[OID__NR] = {\n";
for (my $i = 0; $i <= $#names; $i++) {
    my @octets = @{$encoded_oids[$index_table[$i]]};
    printf(C_FILE "\t[%3u] = { %3u, OID_%-35s }, // ",
	   $i,
	   $hash_values[$index_table[$i]],
	   $names[$index_table[$i]]);
    printf C_FILE "%02x", $_ foreach (@octets);
    print C_FILE "\n";
}
print C_FILE "};\n";

#
# Emit the OID debugging name table
#
#print C_FILE "\n";
#print C_FILE "const char *const oid_name_table[OID__NR + 1] = {\n";
#
#for (my $i = 0; $i <= $#names; $i++) {
#    print C_FILE "\t\"", $names[$i], "\",\n"
#}
#print C_FILE "\t\"Unknown-OID\"\n";
#print C_FILE "};\n";

#
# Polish off
#
close C_FILE or die;