summaryrefslogtreecommitdiffstats
path: root/scripts/extract-sys-certs.pl
blob: 2aa873b944e0a5666868c91760b4d9829006e759 (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
#!/usr/bin/env perl
#
use warnings;
use strict;
use Math::BigInt;
use Fcntl "SEEK_SET";

die "Format: $0 [-s <systemmap-file>] <vmlinux-file> <keyring-file>\n"
    if ($#ARGV != 1 && $#ARGV != 3 ||
	$#ARGV == 3 && $ARGV[0] ne "-s");

my $sysmap = "";
if ($#ARGV == 3) {
    shift;
    $sysmap = $ARGV[0];
    shift;
}

my $vmlinux = $ARGV[0];
my $keyring = $ARGV[1];

#
# Parse the vmlinux section table
#
open FD, "objdump -h $vmlinux |" || die $vmlinux;
my @lines = <FD>;
close(FD) || die $vmlinux;

my @sections = ();

foreach my $line (@lines) {
    chomp($line);
    if ($line =~ /\s*([0-9]+)\s+(\S+)\s+([0-9a-f]+)\s+([0-9a-f]+)\s+([0-9a-f]+)\s+([0-9a-f]+)\s+2[*][*]([0-9]+)/
	) {
	my $seg  = $1;
	my $name = $2;
	my $len  = Math::BigInt->new("0x" . $3);
	my $vma  = Math::BigInt->new("0x" . $4);
	my $lma  = Math::BigInt->new("0x" . $5);
	my $foff = Math::BigInt->new("0x" . $6);
	my $align = 2 ** $7;

	push @sections, { name => $name,
			  vma => $vma,
			  len => $len,
			  foff => $foff };
    }
}

print "Have $#sections sections\n";

#
# Try and parse the vmlinux symbol table.  If the vmlinux file has been created
# from a vmlinuz file with extract-vmlinux then the symbol table will be empty.
#
open FD, "nm $vmlinux 2>/dev/null |" || die $vmlinux;
@lines = <FD>;
close(FD) || die $vmlinux;

my %symbols = ();
my $nr_symbols = 0;

sub parse_symbols(@) {
    foreach my $line (@_) {
	chomp($line);
	if ($line =~ /([0-9a-f]+)\s([a-zA-Z])\s(\S+)/
	    ) {
	    my $addr = "0x" . $1;
	    my $type = $2;
	    my $name = $3;

	    $symbols{$name} = $addr;
	    $nr_symbols++;
	}
    }
}
parse_symbols(@lines);

if ($nr_symbols == 0 && $sysmap ne "") {
    print "No symbols in vmlinux, trying $sysmap\n";

    open FD, "<$sysmap" || die $sysmap;
    @lines = <FD>;
    close(FD) || die $sysmap;
    parse_symbols(@lines);
}

die "No symbols available\n"
    if ($nr_symbols == 0);

print "Have $nr_symbols symbols\n";

die "Can't find system certificate list"
    unless (exists($symbols{"__cert_list_start"}) &&
	    exists($symbols{"system_certificate_list_size"}));

my $start = Math::BigInt->new($symbols{"__cert_list_start"});
my $end;
my $size;
my $size_sym = Math::BigInt->new($symbols{"system_certificate_list_size"});

open FD, "<$vmlinux" || die $vmlinux;
binmode(FD);

my $s = undef;
foreach my $sec (@sections) {
    my $s_name = $sec->{name};
    my $s_vma = $sec->{vma};
    my $s_len = $sec->{len};
    my $s_foff = $sec->{foff};
    my $s_vend = $s_vma + $s_len;

    next unless ($start >= $s_vma);
    next if ($start >= $s_vend);

    die "Certificate list size was not found on the same section\n"
	if ($size_sym < $s_vma || $size_sym > $s_vend);

    die "Cert object in multiple sections: ", $s_name, " and ", $s->{name}, "\n"
	if ($s);

    my $size_off = $size_sym -$s_vma + $s_foff;
    my $packed;
    die $vmlinux if (!defined(sysseek(FD, $size_off, SEEK_SET)));
    sysread(FD, $packed, 8);
    $size = unpack 'L!', $packed;
    $end = $start + $size;

    printf "Have %u bytes of certs at VMA 0x%x\n", $size, $start;

    die "Cert object partially overflows section $s_name\n"
	if ($end > $s_vend);

    $s = $sec;
}

die "Cert object not inside a section\n"
    unless ($s);

print "Certificate list in section ", $s->{name}, "\n";

my $foff = $start - $s->{vma} + $s->{foff};

printf "Certificate list at file offset 0x%x\n", $foff;

die $vmlinux if (!defined(sysseek(FD, $foff, SEEK_SET)));
my $buf = "";
my $len = sysread(FD, $buf, $size);
die "$vmlinux" if (!defined($len));
die "Short read on $vmlinux\n" if ($len != $size);
close(FD) || die $vmlinux;

open FD, ">$keyring" || die $keyring;
binmode(FD);
$len = syswrite(FD, $buf, $size);
die "$keyring" if (!defined($len));
die "Short write on $keyring\n" if ($len != $size);
close(FD) || die $keyring;
OpenPOWER on IntegriCloud