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// SPDX-License-Identifier: GPL-2.0-only/* * Crypto user configuration API. * * Copyright (C) 2011 secunet Security Networks AG * Copyright (C) 2011 Steffen Klassert <steffen.klassert@secunet.com> */ #include <linux/module.h>#include <linux/crypto.h>#include <linux/cryptouser.h>#include <linux/sched.h>#include <linux/security.h>#include <linux/string.h>#include <net/netlink.h>#include <net/net_namespace.h>#include <net/sock.h>#include <crypto/internal/skcipher.h>#include <crypto/internal/rng.h>#include <crypto/akcipher.h>#include <crypto/kpp.h> #include "internal.h" #define null_terminated(x)	(strnlen(x, sizeof(x)) < sizeof(x)) static DEFINE_MUTEX(crypto_cfg_mutex); 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){	struct crypto_alg *q, *alg = NULL; 	down_read(&crypto_alg_sem); 	list_for_each_entry(q, &crypto_alg_list, cra_list) {		int match = 0; 		if (crypto_is_larval(q))			continue; 		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)			continue; 		if (unlikely(!crypto_mod_get(q)))			continue; 		alg = q;		break;	} 	up_read(&crypto_alg_sem); 	return alg;} static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg){	struct crypto_report_cipher rcipher = {		.type = "cipher",	}; 	rcipher.blocksize = alg->cra_blocksize;	rcipher.min_keysize = alg->cra_cipher.cia_min_keysize;	rcipher.max_keysize = alg->cra_cipher.cia_max_keysize; 	return nla_put(skb, CRYPTOCFGA_REPORT_CIPHER,		       sizeof(rcipher), &rcipher);} static int crypto_report_one(struct crypto_alg *alg,			     struct crypto_user_alg *ualg, struct sk_buff *skb){	memset(ualg, 0, sizeof(*ualg)); 	strscpy(ualg->cru_name, alg->cra_name);	strscpy(ualg->cru_driver_name, alg->cra_driver_name);	strscpy(ualg->cru_module_name, module_name(alg->cra_module)); 	ualg->cru_type = 0;	ualg->cru_mask = 0;	ualg->cru_flags = alg->cra_flags;	ualg->cru_refcnt = refcount_read(&alg->cra_refcnt); 	if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority))		goto nla_put_failure;	if (alg->cra_flags & CRYPTO_ALG_LARVAL) {		struct crypto_report_larval rl = {			.type = "larval",		}; 		if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL, sizeof(rl), &rl))			goto nla_put_failure;		goto out;	} 	if (alg->cra_type && alg->cra_type->report) {		if (alg->cra_type->report(skb, alg))			goto nla_put_failure; 		goto out;	} 	switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) {	case CRYPTO_ALG_TYPE_CIPHER:		if (crypto_report_cipher(skb, alg))			goto nla_put_failure; 		break;	} out:	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).portid, 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 net *net = sock_net(in_skb->sk);	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 (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))		return -EINVAL; 	alg = crypto_alg_match(p, 0);	if (!alg)		return -ENOENT; 	err = -ENOMEM;	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);	if (!skb)		goto drop_alg; 	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); drop_alg:	crypto_mod_put(alg); 	if (err) {		kfree_skb(skb);		return err;	} 	return nlmsg_unicast(net->crypto_nlsk, skb, NETLINK_CB(in_skb).portid);} static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb){	const size_t start_pos = cb->args[0];	size_t pos = 0;	struct crypto_dump_info info;	struct crypto_alg *alg;	int res; 	info.in_skb = cb->skb;	info.out_skb = skb;	info.nlmsg_seq = cb->nlh->nlmsg_seq;	info.nlmsg_flags = NLM_F_MULTI; 	down_read(&crypto_alg_sem);	list_for_each_entry(alg, &crypto_alg_list, cra_list) {		if (pos >= start_pos) {			res = crypto_report_alg(alg, &info);			if (res == -EMSGSIZE)				break;			if (res)				goto out;		}		pos++;	}	cb->args[0] = pos;	res = skb->len;out:	up_read(&crypto_alg_sem);	return res;} 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 (!netlink_capable(skb, CAP_NET_ADMIN))		return -EPERM; 	if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))		return -EINVAL; 	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_mod_put(alg);	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);	int err; 	if (!netlink_capable(skb, CAP_NET_ADMIN))		return -EPERM; 	if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))		return -EINVAL; 	alg = crypto_alg_match(p, 1);	if (!alg)		return -ENOENT; 	/* We can not unregister core algorithms such as aes.	 * 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. */	err = -EINVAL;	if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))		goto drop_alg; 	err = -EBUSY;	if (refcount_read(&alg->cra_refcnt) > 2)		goto drop_alg; 	crypto_unregister_instance((struct crypto_instance *)alg);	err = 0; drop_alg:	crypto_mod_put(alg);	return err;} static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,			  struct nlattr **attrs){	int exact = 0;	const char *name;	struct crypto_alg *alg;	struct crypto_user_alg *p = nlmsg_data(nlh);	struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL]; 	if (!netlink_capable(skb, CAP_NET_ADMIN))		return -EPERM; 	if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))		return -EINVAL; 	if (strlen(p->cru_driver_name))		exact = 1; 	if (priority && !exact)		return -EINVAL; 	alg = crypto_alg_match(p, exact);	if (alg) {		crypto_mod_put(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;} static int crypto_del_rng(struct sk_buff *skb, struct nlmsghdr *nlh,			  struct nlattr **attrs){	if (!netlink_capable(skb, CAP_NET_ADMIN))		return -EPERM;	return crypto_del_default_rng();} static int crypto_reportstat(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,			     struct nlattr **attrs){	/* No longer supported */	return -ENOTSUPP;} #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),	[CRYPTO_MSG_DELRNG	- CRYPTO_MSG_BASE] = 0,	[CRYPTO_MSG_GETSTAT	- 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 const 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},	[CRYPTO_MSG_DELRNG	- CRYPTO_MSG_BASE] = { .doit = crypto_del_rng },	[CRYPTO_MSG_GETSTAT	- CRYPTO_MSG_BASE] = { .doit = crypto_reportstat},}; static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,			       struct netlink_ext_ack *extack){	struct net *net = sock_net(skb->sk);	struct nlattr *attrs[CRYPTOCFGA_MAX+1];	const 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 ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&	    (nlh->nlmsg_flags & NLM_F_DUMP))) {		struct crypto_alg *alg;		unsigned long dump_alloc = 0; 		if (link->dump == NULL)			return -EINVAL; 		down_read(&crypto_alg_sem);		list_for_each_entry(alg, &crypto_alg_list, cra_list)			dump_alloc += CRYPTO_REPORT_MAXSIZE;		up_read(&crypto_alg_sem); 		{			struct netlink_dump_control c = {				.dump = link->dump,				.done = link->done,				.min_dump_alloc = min(dump_alloc, 65535UL),			};			err = netlink_dump_start(net->crypto_nlsk, skb, nlh, &c);		} 		return err;	} 	err = nlmsg_parse_deprecated(nlh, crypto_msg_min[type], attrs,				     CRYPTOCFGA_MAX, crypto_policy, extack);	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 __net_init crypto_netlink_init(struct net *net){	struct netlink_kernel_cfg cfg = {		.input	= crypto_netlink_rcv,	}; 	net->crypto_nlsk = netlink_kernel_create(net, NETLINK_CRYPTO, &cfg);	return net->crypto_nlsk == NULL ? -ENOMEM : 0;} static void __net_exit crypto_netlink_exit(struct net *net){	netlink_kernel_release(net->crypto_nlsk);	net->crypto_nlsk = NULL;} static struct pernet_operations crypto_netlink_net_ops = {	.init = crypto_netlink_init,	.exit = crypto_netlink_exit,}; static int __init crypto_user_init(void){	return register_pernet_subsys(&crypto_netlink_net_ops);} static void __exit crypto_user_exit(void){	unregister_pernet_subsys(&crypto_netlink_net_ops);} module_init(crypto_user_init);module_exit(crypto_user_exit);MODULE_LICENSE("GPL");

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