1 files changed, 275 insertions, 0 deletions
diff --git a/src/crypto/certstore.c b/src/crypto/certstore.c
new file mode 100644
index 00000000..77cf6ebb
--- /dev/null
+++ b/src/crypto/certstore.c
@@ -0,0 +1,275 @@
+/*
+ * 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.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#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 asn1_cursor *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->data, key->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 ) );
+}
+
+/**
+ * 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 ) {
+		if ( cert->refcnt.count == 0 ) {
+			DBGC ( &certstore, "CERTSTORE discarded certificate "
+			       "%s\n", x509_name ( cert ) );
+			list_del ( &cert->store.list );
+			x509_put ( 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 );
+		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,
+};