diff options
Diffstat (limited to 'crypto/crypto_user.c')
| -rw-r--r-- | crypto/crypto_user.c | 574 |
1 files changed, 574 insertions, 0 deletions
diff --git a/crypto/crypto_user.c b/crypto/crypto_user.c new file mode 100644 index 000000000..f847c181a --- /dev/null +++ b/crypto/crypto_user.c @@ -0,0 +1,574 @@ +/* + * 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 <linux/sched.h> +#include <net/netlink.h> +#include <linux/security.h> +#include <net/net_namespace.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); + +/* 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) +{ + 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; + + strncpy(rcipher.type, "cipher", sizeof(rcipher.type)); + + rcipher.blocksize = alg->cra_blocksize; + rcipher.min_keysize = alg->cra_cipher.cia_min_keysize; + rcipher.max_keysize = alg->cra_cipher.cia_max_keysize; + + if (nla_put(skb, CRYPTOCFGA_REPORT_CIPHER, + sizeof(struct crypto_report_cipher), &rcipher)) + goto nla_put_failure; + return 0; + +nla_put_failure: + return -EMSGSIZE; +} + +static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg) +{ + struct crypto_report_comp rcomp; + + strncpy(rcomp.type, "compression", sizeof(rcomp.type)); + if (nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS, + sizeof(struct crypto_report_comp), &rcomp)) + goto nla_put_failure; + return 0; + +nla_put_failure: + return -EMSGSIZE; +} + +static int crypto_report_acomp(struct sk_buff *skb, struct crypto_alg *alg) +{ + struct crypto_report_acomp racomp; + + strncpy(racomp.type, "acomp", sizeof(racomp.type)); + + if (nla_put(skb, CRYPTOCFGA_REPORT_ACOMP, + sizeof(struct crypto_report_acomp), &racomp)) + goto nla_put_failure; + return 0; + +nla_put_failure: + return -EMSGSIZE; +} + +static int crypto_report_akcipher(struct sk_buff *skb, struct crypto_alg *alg) +{ + struct crypto_report_akcipher rakcipher; + + strncpy(rakcipher.type, "akcipher", sizeof(rakcipher.type)); + + if (nla_put(skb, CRYPTOCFGA_REPORT_AKCIPHER, + sizeof(struct crypto_report_akcipher), &rakcipher)) + goto nla_put_failure; + return 0; + +nla_put_failure: + return -EMSGSIZE; +} + +static int crypto_report_kpp(struct sk_buff *skb, struct crypto_alg *alg) +{ + struct crypto_report_kpp rkpp; + + strncpy(rkpp.type, "kpp", sizeof(rkpp.type)); + + if (nla_put(skb, CRYPTOCFGA_REPORT_KPP, + sizeof(struct crypto_report_kpp), &rkpp)) + goto nla_put_failure; + return 0; + +nla_put_failure: + return -EMSGSIZE; +} + +static int crypto_report_one(struct crypto_alg *alg, + struct crypto_user_alg *ualg, struct sk_buff *skb) +{ + strncpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name)); + strncpy(ualg->cru_driver_name, alg->cra_driver_name, + sizeof(ualg->cru_driver_name)); + strncpy(ualg->cru_module_name, module_name(alg->cra_module), + sizeof(ualg->cru_module_name)); + + 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; + + strncpy(rl.type, "larval", sizeof(rl.type)); + if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL, + sizeof(struct crypto_report_larval), &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; + case CRYPTO_ALG_TYPE_COMPRESS: + if (crypto_report_comp(skb, alg)) + goto nla_put_failure; + + break; + case CRYPTO_ALG_TYPE_ACOMPRESS: + if (crypto_report_acomp(skb, alg)) + goto nla_put_failure; + + break; + case CRYPTO_ALG_TYPE_AKCIPHER: + if (crypto_report_akcipher(skb, alg)) + goto nla_put_failure; + + break; + case CRYPTO_ALG_TYPE_KPP: + if (crypto_report_kpp(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 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(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-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. */ + err = -EINVAL; + if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE)) + goto drop_alg; + + err = -EBUSY; + if (refcount_read(&alg->cra_refcnt) > 2) + goto drop_alg; + + err = crypto_unregister_instance((struct crypto_instance *)alg); + +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(); +} + +#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, +}; + +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 }, +}; + +static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + 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(crypto_nlsk, skb, nlh, &c); + } + + return err; + } + + err = nlmsg_parse(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 __init crypto_user_init(void) +{ + struct netlink_kernel_cfg cfg = { + .input = crypto_netlink_rcv, + }; + + crypto_nlsk = netlink_kernel_create(&init_net, NETLINK_CRYPTO, &cfg); + 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"); +MODULE_ALIAS("net-pf-16-proto-21"); |