wolfssh/gencertbuf.pl

#!/usr/bin/perl

# gencertbuf.pl
# version 1.0
# Updated 04/08/2019
#
# Copyright (C) 2014-2022 wolfSSL Inc.
#

use strict;
use warnings;

# ---- SCRIPT SETTINGS -------------------------------------------------------

# output C header file to write key buffers to
my $outputFile = "./wolfssh/certs_test.h";

# Add a suffix to distinguish between wolfssl/certs_test.h
my $SSH_SUFFIX = "_ssh";

# ecc keys to be converted

my @fileList_ecc = (
        [ "./keys/server-key-ecc.der",        "ecc_key_der_256" ],
        [ "./keys/server-key-ecc-384.der",    "ecc_key_der_384" ],
        [ "./keys/server-key-ecc-521.der",    "ecc_key_der_521" ]
        );


# 2048-bit keys to be converted

my @fileList_2048 = (
        [ "./keys/server-key-rsa.der", "rsa_key_der_2048" ],
        );

# ----------------------------------------------------------------------------

my $num_ecc = @fileList_ecc;
my $num_2048 = @fileList_2048;

# open our output file, "+>" creates and/or truncates
open OUT_FILE, "+>", $outputFile  or die $!;

print OUT_FILE "/* certs_test.h\n";
print OUT_FILE " *\n";
print OUT_FILE " * Copyright (C) 2014-2025 wolfSSL Inc.\n";
print OUT_FILE " *\n";
print OUT_FILE " * This file is part of wolfSSH.\n";
print OUT_FILE " *\n";
print OUT_FILE " * wolfSSH is free software; you can redistribute it and/or modify\n";
print OUT_FILE " * it under the terms of the GNU General Public License as published by\n";
print OUT_FILE " * the Free Software Foundation; either version 3 of the License, or\n";
print OUT_FILE " * (at your option) any later version.\n";
print OUT_FILE " *\n";
print OUT_FILE " * wolfSSH is distributed in the hope that it will be useful,\n";
print OUT_FILE " * but WITHOUT ANY WARRANTY; without even the implied warranty of\n";
print OUT_FILE " * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\n";
print OUT_FILE " * GNU General Public License for more details.\n";
print OUT_FILE " *\n";
print OUT_FILE " * You should have received a copy of the GNU General Public License\n";
print OUT_FILE " * along with wolfSSH.  If not, see <http://www.gnu.org/licenses/>.\n";
print OUT_FILE " */\n\n";
print OUT_FILE "#ifndef _WOLFSSH_CERTS_TEST_H_\n";
print OUT_FILE "#define _WOLFSSH_CERTS_TEST_H_\n";
print OUT_FILE "\n";
print OUT_FILE "/* To distinguish these certs from those in wolfssl add suffix: _ssh\n";
print OUT_FILE " * See: https://github.com/wolfSSL/wolfssl/blob/master/wolfssl/certs_test.h\n";
print OUT_FILE " * Generate: https://github.com/wolfSSL/wolfssl/blob/master/gencertbuf.pl\n";
print OUT_FILE " *\n";
print OUT_FILE " * In C89/C90 (which Watcom generally defaults to), sizeof must be a\n";
print OUT_FILE " * compile-time constant expression when used in a static initializer.\n";
print OUT_FILE " * So don't use `static const int sizeof_`\n";
print OUT_FILE " */\n";
print OUT_FILE "\n";

# convert and print 2048-bit certs/keys
print OUT_FILE "#if defined(NO_FILESYSTEM)\n\n";
for (my $i = 0; $i < $num_2048; $i++) {

    my $fname = $fileList_2048[$i][0];
    my $sname = $fileList_2048[$i][1];

    # Add a suffix to distinguish between wolfssl/certs_test.h
    $sname .= $SSH_SUFFIX;

    print OUT_FILE "/* $fname, 2048-bit */\n";
    print OUT_FILE "static const unsigned char $sname\[] =\n";
    print OUT_FILE "{\n";
    file_to_hex($fname);
    print OUT_FILE "};\n";

    # In C89/C90 (which Watcom generally defaults to), sizeof must be a
    # compile-time constant expression when used in a static initializer.
    # So don't use `static const int sizeof_` here:
    print OUT_FILE "#define sizeof_$sname (sizeof($sname))\n\n"
}

# convert and print ECC cert/keys
for (my $i = 0; $i < $num_ecc; $i++) {

    my $fname = $fileList_ecc[$i][0];
    my $sname = $fileList_ecc[$i][1];

    # Add a suffix to distinguish between wolfssl/certs_test.h
    $sname .= $SSH_SUFFIX;

    print OUT_FILE "/* $fname, ECC */\n";
    print OUT_FILE "static const unsigned char $sname\[] =\n";
    print OUT_FILE "{\n";
    file_to_hex($fname);
    print OUT_FILE "};\n";

    # In C89/C90 (which Watcom generally defaults to), sizeof must be a
    # compile-time constant expression when used in a static initializer.
    # So don't use `static const int sizeof_` here:
    print OUT_FILE "#define sizeof_$sname (sizeof($sname))\n\n"
}

print OUT_FILE "#endif /* NO_FILESYSTEM */\n\n";
print OUT_FILE "#endif /* _WOLFSSL_CERTS_TEST_H_ */\n\n";

# close certs_test.h file
close OUT_FILE or die $!;

# print file as hex, comma-separated, as needed by C buffer
sub file_to_hex {
    my $fileName = $_[0];

    open my $fp, "<", $fileName or die $!;
    binmode($fp);

    my $fileLen = -s $fileName;
    my $byte;

    for (my $i = 0, my $j = 1; $i < $fileLen; $i++, $j++)
    {
        # Indent 4 spaces
        if ($j == 1) {
            print OUT_FILE "    ";
        }

        read($fp, $byte, 1) or die "Error reading $fileName";
        my $output = sprintf("0x%02X", ord($byte));
        print OUT_FILE $output;

        # comma at the end of the array declaration
        if ($i != ($fileLen - 1)) {
            print OUT_FILE ",";
        }

        if ($j == 10) {
            $j = 0;
            print OUT_FILE "\n";
        }
        else {
            # Space between each byte, except last one
            if ($i < $fileLen - 1) {
                print OUT_FILE " ";
            }
        }
    }

    print OUT_FILE "\n";

    close($fp);
}