Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit a38f7907 authored by Steffen Klassert's avatar Steffen Klassert Committed by Herbert Xu
Browse files

crypto: Add userspace configuration API 



This patch adds a basic userspace configuration API for the crypto layer.
With this it is possible to instantiate, remove and to show crypto
algorithms from userspace.

Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 22e5b20b

crypto/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -100,6 +100,13 @@ config CRYPTO_MANAGER2 
	select CRYPTO_BLKCIPHER2

	select CRYPTO_PCOMP2



config CRYPTO_USER

	tristate "Userspace cryptographic algorithm configuration"

	select CRYPTO_MANAGER

	help

	  Userapace configuration for cryptographic instantiations such as

	  cbc(aes).



config CRYPTO_MANAGER_DISABLE_TESTS

	bool "Disable run-time self tests"

	default y

crypto/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ obj-$(CONFIG_CRYPTO_PCOMP2) += pcompress.o 
cryptomgr-y := algboss.o testmgr.o



obj-$(CONFIG_CRYPTO_MANAGER2) += cryptomgr.o

obj-$(CONFIG_CRYPTO_USER) += crypto_user.o

obj-$(CONFIG_CRYPTO_HMAC) += hmac.o

obj-$(CONFIG_CRYPTO_VMAC) += vmac.o

obj-$(CONFIG_CRYPTO_XCBC) += xcbc.o

crypto/crypto_user.c

0 → 100644
+372 −0
Original line number Diff line number Diff line 
/*

 * Crypto user configuration API.

 *

 * Copyright (C) 2011 secunet Security Networks AG

 * Copyright (C) 2011 Steffen Klassert <steffen.klassert@secunet.com>

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms and conditions of the GNU General Public License,

 * version 2, as published by the Free Software Foundation.

 *

 * This program is distributed in the hope 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 St - Fifth Floor, Boston, MA 02110-1301 USA.

 */



#include <linux/module.h>

#include <linux/crypto.h>

#include <linux/cryptouser.h>

#include <net/netlink.h>

#include <linux/security.h>

#include <net/net_namespace.h>

#include "internal.h"



DEFINE_MUTEX(crypto_cfg_mutex);



/* The crypto netlink socket */

static struct sock *crypto_nlsk;



struct crypto_dump_info {

	struct sk_buff *in_skb;

	struct sk_buff *out_skb;

	u32 nlmsg_seq;

	u16 nlmsg_flags;

};



static struct crypto_alg *crypto_alg_match(struct crypto_user_alg *p, int exact)

{

	int match;

	struct crypto_alg *q, *alg = NULL;



	down_read(&crypto_alg_sem);



	if (list_empty(&crypto_alg_list))

		return NULL;



	list_for_each_entry(q, &crypto_alg_list, cra_list) {



		if ((q->cra_flags ^ p->cru_type) & p->cru_mask)

			continue;



		if (strlen(p->cru_driver_name))

			match = !strcmp(q->cra_driver_name,

					p->cru_driver_name);

		else if (!exact)

			match = !strcmp(q->cra_name, p->cru_name);



		if (match) {

			alg = q;

			break;

		}

	}



	up_read(&crypto_alg_sem);



	return alg;

}



static int crypto_report_one(struct crypto_alg *alg,

			     struct crypto_user_alg *ualg, struct sk_buff *skb)

{

	memcpy(&ualg->cru_name, &alg->cra_name, sizeof(ualg->cru_name));

	memcpy(&ualg->cru_driver_name, &alg->cra_driver_name,

	       sizeof(ualg->cru_driver_name));

	memcpy(&ualg->cru_module_name, module_name(alg->cra_module),

	       CRYPTO_MAX_ALG_NAME);



	ualg->cru_flags = alg->cra_flags;

	ualg->cru_refcnt = atomic_read(&alg->cra_refcnt);



	NLA_PUT_U32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority);



	return 0;



nla_put_failure:

	return -EMSGSIZE;

}



static int crypto_report_alg(struct crypto_alg *alg,

			     struct crypto_dump_info *info)

{

	struct sk_buff *in_skb = info->in_skb;

	struct sk_buff *skb = info->out_skb;

	struct nlmsghdr *nlh;

	struct crypto_user_alg *ualg;

	int err = 0;



	nlh = nlmsg_put(skb, NETLINK_CB(in_skb).pid, info->nlmsg_seq,

			CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags);

	if (!nlh) {

		err = -EMSGSIZE;

		goto out;

	}



	ualg = nlmsg_data(nlh);



	err = crypto_report_one(alg, ualg, skb);

	if (err) {

		nlmsg_cancel(skb, nlh);

		goto out;

	}



	nlmsg_end(skb, nlh);



out:

	return err;

}



static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,

			 struct nlattr **attrs)

{

	struct crypto_user_alg *p = nlmsg_data(in_nlh);

	struct crypto_alg *alg;

	struct sk_buff *skb;

	struct crypto_dump_info info;

	int err;



	if (!p->cru_driver_name)

		return -EINVAL;



	alg = crypto_alg_match(p, 1);

	if (!alg)

		return -ENOENT;



	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);

	if (!skb)

		return -ENOMEM;



	info.in_skb = in_skb;

	info.out_skb = skb;

	info.nlmsg_seq = in_nlh->nlmsg_seq;

	info.nlmsg_flags = 0;



	err = crypto_report_alg(alg, &info);

	if (err)

		return err;



	return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).pid);

}



static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb)

{

	struct crypto_alg *alg;

	struct crypto_dump_info info;

	int err;



	if (cb->args[0])

		goto out;



	cb->args[0] = 1;



	info.in_skb = cb->skb;

	info.out_skb = skb;

	info.nlmsg_seq = cb->nlh->nlmsg_seq;

	info.nlmsg_flags = NLM_F_MULTI;



	list_for_each_entry(alg, &crypto_alg_list, cra_list) {

		err = crypto_report_alg(alg, &info);

		if (err)

			goto out_err;

	}



out:

	return skb->len;

out_err:

	return err;

}



static int crypto_dump_report_done(struct netlink_callback *cb)

{

	return 0;

}



static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh,

			     struct nlattr **attrs)

{

	struct crypto_alg *alg;

	struct crypto_user_alg *p = nlmsg_data(nlh);

	struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];

	LIST_HEAD(list);



	if (priority && !strlen(p->cru_driver_name))

		return -EINVAL;



	alg = crypto_alg_match(p, 1);

	if (!alg)

		return -ENOENT;



	down_write(&crypto_alg_sem);



	crypto_remove_spawns(alg, &list, NULL);



	if (priority)

		alg->cra_priority = nla_get_u32(priority);



	up_write(&crypto_alg_sem);



	crypto_remove_final(&list);



	return 0;

}



static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,

			  struct nlattr **attrs)

{

	struct crypto_alg *alg;

	struct crypto_user_alg *p = nlmsg_data(nlh);



	alg = crypto_alg_match(p, 1);

	if (!alg)

		return -ENOENT;



	/* We can not unregister core algorithms such as aes-generic.

	 * We would loose the reference in the crypto_alg_list to this algorithm

	 * if we try to unregister. Unregistering such an algorithm without

	 * removing the module is not possible, so we restrict to crypto

	 * instances that are build from templates. */

	if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))

		return -EINVAL;



	if (atomic_read(&alg->cra_refcnt) != 1)

		return -EBUSY;



	return crypto_unregister_alg(alg);

}



static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,

			  struct nlattr **attrs)

{

	int exact;

	const char *name;

	struct crypto_alg *alg;

	struct crypto_user_alg *p = nlmsg_data(nlh);

	struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];



	if (strlen(p->cru_driver_name))

		exact = 1;



	if (priority && !exact)

		return -EINVAL;



	alg = crypto_alg_match(p, exact);

	if (alg)

		return -EEXIST;



	if (strlen(p->cru_driver_name))

		name = p->cru_driver_name;

	else

		name = p->cru_name;



	alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);

	if (IS_ERR(alg))

		return PTR_ERR(alg);



	down_write(&crypto_alg_sem);



	if (priority)

		alg->cra_priority = nla_get_u32(priority);



	up_write(&crypto_alg_sem);



	crypto_mod_put(alg);



	return 0;

}



#define MSGSIZE(type) sizeof(struct type)



static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = {

	[CRYPTO_MSG_NEWALG	- CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),

	[CRYPTO_MSG_DELALG	- CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),

	[CRYPTO_MSG_UPDATEALG	- CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),

	[CRYPTO_MSG_GETALG	- CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),

};



static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = {

	[CRYPTOCFGA_PRIORITY_VAL]   = { .type = NLA_U32},

};



#undef MSGSIZE



static struct crypto_link {

	int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);

	int (*dump)(struct sk_buff *, struct netlink_callback *);

	int (*done)(struct netlink_callback *);

} crypto_dispatch[CRYPTO_NR_MSGTYPES] = {

	[CRYPTO_MSG_NEWALG	- CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},

	[CRYPTO_MSG_DELALG	- CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},

	[CRYPTO_MSG_UPDATEALG	- CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},

	[CRYPTO_MSG_GETALG	- CRYPTO_MSG_BASE] = { .doit = crypto_report,

						       .dump = crypto_dump_report,

						       .done = crypto_dump_report_done},

};



static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)

{

	struct nlattr *attrs[CRYPTOCFGA_MAX+1];

	struct crypto_link *link;

	int type, err;



	type = nlh->nlmsg_type;

	if (type > CRYPTO_MSG_MAX)

		return -EINVAL;



	type -= CRYPTO_MSG_BASE;

	link = &crypto_dispatch[type];



	if (security_netlink_recv(skb, CAP_NET_ADMIN))

		return -EPERM;



	if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&

	    (nlh->nlmsg_flags & NLM_F_DUMP))) {

		if (link->dump == NULL)

			return -EINVAL;



		return netlink_dump_start(crypto_nlsk, skb, nlh,

					  link->dump, link->done, 0);

	}



	err = nlmsg_parse(nlh, crypto_msg_min[type], attrs, CRYPTOCFGA_MAX,

			  crypto_policy);

	if (err < 0)

		return err;



	if (link->doit == NULL)

		return -EINVAL;



	return link->doit(skb, nlh, attrs);

}



static void crypto_netlink_rcv(struct sk_buff *skb)

{

	mutex_lock(&crypto_cfg_mutex);

	netlink_rcv_skb(skb, &crypto_user_rcv_msg);

	mutex_unlock(&crypto_cfg_mutex);

}



static int __init crypto_user_init(void)

{

	crypto_nlsk = netlink_kernel_create(&init_net, NETLINK_CRYPTO,

					    0, crypto_netlink_rcv,

					    NULL, THIS_MODULE);

	if (!crypto_nlsk)

		return -ENOMEM;



	return 0;

}



static void __exit crypto_user_exit(void)

{

	netlink_kernel_release(crypto_nlsk);

}



module_init(crypto_user_init);

module_exit(crypto_user_exit);

MODULE_LICENSE("GPL");

MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");

MODULE_DESCRIPTION("Crypto userspace configuration API");

include/linux/cryptouser.h

0 → 100644
+52 −0
Original line number Diff line number Diff line 
/*

 * Crypto user configuration API.

 *

 * Copyright (C) 2011 secunet Security Networks AG

 * Copyright (C) 2011 Steffen Klassert <steffen.klassert@secunet.com>

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms and conditions of the GNU General Public License,

 * version 2, as published by the Free Software Foundation.

 *

 * This program is distributed in the hope 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 St - Fifth Floor, Boston, MA 02110-1301 USA.

 */



/* Netlink configuration messages.  */

enum {

	CRYPTO_MSG_BASE = 0x10,

	CRYPTO_MSG_NEWALG = 0x10,

	CRYPTO_MSG_DELALG,

	CRYPTO_MSG_UPDATEALG,

	CRYPTO_MSG_GETALG,

	__CRYPTO_MSG_MAX

};

#define CRYPTO_MSG_MAX (__CRYPTO_MSG_MAX - 1)

#define CRYPTO_NR_MSGTYPES (CRYPTO_MSG_MAX + 1 - CRYPTO_MSG_BASE)



#define CRYPTO_MAX_NAME CRYPTO_MAX_ALG_NAME



/* Netlink message attributes.  */

enum crypto_attr_type_t {

	CRYPTOCFGA_UNSPEC,

	CRYPTOCFGA_PRIORITY_VAL,	/* __u32 */

	__CRYPTOCFGA_MAX



#define CRYPTOCFGA_MAX (__CRYPTOCFGA_MAX - 1)

};



struct crypto_user_alg {

	char cru_name[CRYPTO_MAX_ALG_NAME];

	char cru_driver_name[CRYPTO_MAX_ALG_NAME];

	char cru_module_name[CRYPTO_MAX_ALG_NAME];

	__u32 cru_type;

	__u32 cru_mask;

	__u32 cru_refcnt;

	__u32 cru_flags;

};

include/linux/netlink.h

+1 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#define NETLINK_SCSITRANSPORT	18	/* SCSI Transports */

#define NETLINK_ECRYPTFS	19

#define NETLINK_RDMA		20

#define NETLINK_CRYPTO		21	/* Crypto layer */



#define MAX_LINKS 32