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/*
* Copyright (C) 2014 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 <string.h>
#include <stdlib.h>
#include <ipxe/init.h>
#include <ipxe/dhcp.h>
#include <ipxe/settings.h>
#include <ipxe/malloc.h>
#include <ipxe/crypto.h>
#include <ipxe/asn1.h>
#include <ipxe/x509.h>
#include <ipxe/certstore.h>
/** @file
*
* Certificate store
*
*/
/** Raw certificate data for all permanent stored certificates */
#undef CERT
#define CERT( _index, _path ) \
extern char stored_cert_ ## _index ## _data[]; \
extern char stored_cert_ ## _index ## _len[]; \
__asm__ ( ".section \".rodata\", \"a\", " PROGBITS "\n\t" \
"\nstored_cert_" #_index "_data:\n\t" \
".incbin \"" _path "\"\n\t" \
"\nstored_cert_" #_index "_end:\n\t" \
".equ stored_cert_" #_index "_len, " \
"( stored_cert_" #_index "_end - " \
" stored_cert_" #_index "_data )\n\t" \
".previous\n\t" );
CERT_ALL
/** Raw certificate cursors for all permanent stored certificates */
#undef CERT
#define CERT( _index, _path ) { \
.data = stored_cert_ ## _index ## _data, \
.len = ( size_t ) stored_cert_ ## _index ## _len, \
},
static struct asn1_cursor certstore_raw[] = {
CERT_ALL
};
/** X.509 certificate structures for all permanent stored certificates */
static struct x509_certificate certstore_certs[ sizeof ( certstore_raw ) /
sizeof ( certstore_raw[0] ) ];
/** Certificate store */
struct x509_chain certstore = {
.refcnt = REF_INIT ( ref_no_free ),
.links = LIST_HEAD_INIT ( certstore.links ),
};
/**
* Mark stored certificate as most recently used
*
* @v cert X.509 certificate
* @ret cert X.509 certificate
*/
static struct x509_certificate *
certstore_found ( struct x509_certificate *cert ) {
/* Mark as most recently used */
list_del ( &cert->store.list );
list_add ( &cert->store.list, &certstore.links );
DBGC2 ( &certstore, "CERTSTORE found certificate %s\n",
x509_name ( cert ) );
return cert;
}
/**
* Find certificate in store
*
* @v raw Raw certificate data
* @ret cert X.509 certificate, or NULL if not found
*/
struct x509_certificate * certstore_find ( struct asn1_cursor *raw ) {
struct x509_certificate *cert;
/* Search for certificate within store */
list_for_each_entry ( cert, &certstore.links, store.list ) {
if ( asn1_compare ( raw, &cert->raw ) == 0 )
return certstore_found ( cert );
}
return NULL;
}
/**
* Find certificate in store corresponding to a private key
*
* @v key Private key
* @ret cert X.509 certificate, or NULL if not found
*/
struct x509_certificate * certstore_find_key ( struct private_key *key ) {
struct x509_certificate *cert;
/* Search for certificate within store */
list_for_each_entry ( cert, &certstore.links, store.list ) {
if ( pubkey_match ( cert->signature_algorithm->pubkey,
key->builder.data, key->builder.len,
cert->subject.public_key.raw.data,
cert->subject.public_key.raw.len ) == 0 )
return certstore_found ( cert );
}
return NULL;
}
/**
* Add certificate to store
*
* @v cert X.509 certificate
*/
void certstore_add ( struct x509_certificate *cert ) {
/* Add certificate to store */
cert->store.cert = cert;
x509_get ( cert );
list_add ( &cert->store.list, &certstore.links );
DBGC ( &certstore, "CERTSTORE added certificate %s\n",
x509_name ( cert ) );
}
/**
* Remove certificate from store
*
* @v cert X.509 certificate
*/
void certstore_del ( struct x509_certificate *cert ) {
/* Ignore attempts to remove permanent certificates */
if ( cert->flags & X509_FL_PERMANENT )
return;
/* Remove certificate from store */
DBGC ( &certstore, "CERTSTORE removed certificate %s\n",
x509_name ( cert ) );
list_del ( &cert->store.list );
x509_put ( cert );
}
/**
* Discard a stored certificate
*
* @ret discarded Number of cached items discarded
*/
static unsigned int certstore_discard ( void ) {
struct x509_certificate *cert;
/* Discard the least recently used certificate for which the
* only reference is held by the store itself.
*/
list_for_each_entry_reverse ( cert, &certstore.links, store.list ) {
/* Skip certificates for which another reference is held */
if ( cert->refcnt.count > 0 )
continue;
/* Skip certificates that were added at build time or
* added explicitly at run time.
*/
if ( cert->flags & ( X509_FL_PERMANENT | X509_FL_EXPLICIT ) )
continue;
/* Discard certificate */
certstore_del ( cert );
return 1;
}
return 0;
}
/** Certificate store cache discarder */
struct cache_discarder certstore_discarder __cache_discarder ( CACHE_NORMAL ) ={
.discard = certstore_discard,
};
/**
* Construct permanent certificate store
*
*/
static void certstore_init ( void ) {
struct asn1_cursor *raw;
struct x509_certificate *cert;
int i;
int rc;
/* Skip if we have no permanent stored certificates */
if ( ! sizeof ( certstore_raw ) )
return;
/* Add certificates */
for ( i = 0 ; i < ( int ) ( sizeof ( certstore_raw ) /
sizeof ( certstore_raw[0] ) ) ; i++ ) {
/* Skip if certificate already present in store */
raw = &certstore_raw[i];
if ( ( cert = certstore_find ( raw ) ) != NULL ) {
DBGC ( &certstore, "CERTSTORE permanent certificate %d "
"is a duplicate of %s\n", i, x509_name ( cert ));
continue;
}
/* Parse certificate */
cert = &certstore_certs[i];
ref_init ( &cert->refcnt, ref_no_free );
if ( ( rc = x509_parse ( cert, raw ) ) != 0 ) {
DBGC ( &certstore, "CERTSTORE could not parse "
"permanent certificate %d: %s\n",
i, strerror ( rc ) );
continue;
}
/* Add certificate to store. Certificate will never
* be discarded from the store, since we retain a
* permanent reference to it.
*/
certstore_add ( cert );
cert->flags |= X509_FL_PERMANENT;
DBGC ( &certstore, "CERTSTORE permanent certificate %d is %s\n",
i, x509_name ( cert ) );
}
}
/** Certificate store initialisation function */
struct init_fn certstore_init_fn __init_fn ( INIT_LATE ) = {
.initialise = certstore_init,
};
/** Additional certificate setting */
static struct setting cert_setting __setting ( SETTING_CRYPTO, cert ) = {
.name = "cert",
.description = "Certificate",
.tag = DHCP_EB_CERT,
.type = &setting_type_hex,
};
/**
* Apply certificate store configuration settings
*
* @ret rc Return status code
*/
static int certstore_apply_settings ( void ) {
static struct x509_certificate *cert = NULL;
struct x509_certificate *old_cert;
void *cert_data;
int len;
int rc;
/* Record any existing additional certificate */
old_cert = cert;
cert = NULL;
/* Add additional certificate, if any */
if ( ( len = fetch_raw_setting_copy ( NULL, &cert_setting,
&cert_data ) ) >= 0 ) {
if ( ( rc = x509_certificate ( cert_data, len, &cert ) ) == 0 ){
DBGC ( &certstore, "CERTSTORE added additional "
"certificate %s\n", x509_name ( cert ) );
} else {
DBGC ( &certstore, "CERTSTORE could not parse "
"additional certificate: %s\n",
strerror ( rc ) );
/* Do not fail; leave as an unusable certificate */
}
free ( cert_data );
}
/* Free old additional certificiate. Do this after reparsing
* the additional certificate; in the common case that the
* certificate has not changed, this will allow the stored
* certificate to be reused.
*/
x509_put ( old_cert );
return 0;
}
/** Certificate store settings applicator */
struct settings_applicator certstore_applicator __settings_applicator = {
.apply = certstore_apply_settings,
};