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/*
* Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <stdlib.h>
#include <errno.h>
#include <time.h>
#include <syslog.h>
#include <ipxe/uaccess.h>
#include <ipxe/image.h>
#include <ipxe/cms.h>
#include <ipxe/validator.h>
#include <ipxe/monojob.h>
#include <usr/imgtrust.h>
/** @file
*
* Image trust management
*
*/
/**
* Verify image using downloaded signature
*
* @v image Image to verify
* @v signature Image containing signature
* @v name Required common name, or NULL to allow any name
* @ret rc Return status code
*/
int imgverify ( struct image *image, struct image *signature,
const char *name ) {
size_t len;
void *data;
struct cms_signature *sig;
struct cms_signer_info *info;
time_t now;
int rc;
/* Mark image as untrusted */
image_untrust ( image );
/* Copy signature to internal memory */
len = signature->len;
data = malloc ( len );
if ( ! data ) {
rc = -ENOMEM;
goto err_alloc;
}
copy_from_user ( data, signature->data, 0, len );
/* Parse signature */
if ( ( rc = cms_signature ( data, len, &sig ) ) != 0 )
goto err_parse;
/* Free internal copy of signature */
free ( data );
data = NULL;
/* Complete all certificate chains */
list_for_each_entry ( info, &sig->info, list ) {
if ( ( rc = create_validator ( &monojob, info->chain ) ) != 0 )
goto err_create_validator;
if ( ( rc = monojob_wait ( NULL, 0 ) ) != 0 )
goto err_validator_wait;
}
/* Use signature to verify image */
now = time ( NULL );
if ( ( rc = cms_verify ( sig, image->data, image->len,
name, now, NULL, NULL ) ) != 0 )
goto err_verify;
/* Drop reference to signature */
cms_put ( sig );
sig = NULL;
/* Mark image as trusted */
image_trust ( image );
syslog ( LOG_NOTICE, "Image \"%s\" signature OK\n", image->name );
return 0;
err_verify:
err_validator_wait:
err_create_validator:
cms_put ( sig );
err_parse:
free ( data );
err_alloc:
syslog ( LOG_ERR, "Image \"%s\" signature bad: %s\n",
image->name, strerror ( rc ) );
return rc;
}
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