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![Herbert Xu](/assets/img/avatar_default.png)
This patch adds a new crypto_user command that allows the admin to delete the crypto system RNG. Note that this can only be done if the RNG is currently not in use. The next time it is used a new system RNG will be allocated. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
588 lines
13 KiB
C
588 lines
13 KiB
C
/*
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* Crypto user configuration API.
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*
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* Copyright (C) 2011 secunet Security Networks AG
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* Copyright (C) 2011 Steffen Klassert <steffen.klassert@secunet.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include <linux/module.h>
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#include <linux/crypto.h>
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#include <linux/cryptouser.h>
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#include <linux/sched.h>
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#include <net/netlink.h>
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#include <linux/security.h>
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#include <net/net_namespace.h>
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#include <crypto/internal/aead.h>
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#include <crypto/internal/skcipher.h>
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#include <crypto/internal/rng.h>
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#include <crypto/akcipher.h>
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#include "internal.h"
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#define null_terminated(x) (strnlen(x, sizeof(x)) < sizeof(x))
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static DEFINE_MUTEX(crypto_cfg_mutex);
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/* The crypto netlink socket */
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static struct sock *crypto_nlsk;
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struct crypto_dump_info {
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struct sk_buff *in_skb;
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struct sk_buff *out_skb;
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u32 nlmsg_seq;
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u16 nlmsg_flags;
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};
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static struct crypto_alg *crypto_alg_match(struct crypto_user_alg *p, int exact)
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{
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struct crypto_alg *q, *alg = NULL;
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down_read(&crypto_alg_sem);
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list_for_each_entry(q, &crypto_alg_list, cra_list) {
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int match = 0;
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if ((q->cra_flags ^ p->cru_type) & p->cru_mask)
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continue;
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if (strlen(p->cru_driver_name))
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match = !strcmp(q->cra_driver_name,
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p->cru_driver_name);
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else if (!exact)
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match = !strcmp(q->cra_name, p->cru_name);
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if (!match)
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continue;
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if (unlikely(!crypto_mod_get(q)))
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continue;
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alg = q;
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break;
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}
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up_read(&crypto_alg_sem);
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return alg;
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}
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static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg)
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{
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struct crypto_report_cipher rcipher;
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strncpy(rcipher.type, "cipher", sizeof(rcipher.type));
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rcipher.blocksize = alg->cra_blocksize;
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rcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
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rcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
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if (nla_put(skb, CRYPTOCFGA_REPORT_CIPHER,
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sizeof(struct crypto_report_cipher), &rcipher))
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goto nla_put_failure;
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return 0;
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nla_put_failure:
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return -EMSGSIZE;
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}
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static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg)
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{
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struct crypto_report_comp rcomp;
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strncpy(rcomp.type, "compression", sizeof(rcomp.type));
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if (nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
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sizeof(struct crypto_report_comp), &rcomp))
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goto nla_put_failure;
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return 0;
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nla_put_failure:
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return -EMSGSIZE;
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}
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static int crypto_report_akcipher(struct sk_buff *skb, struct crypto_alg *alg)
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{
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struct crypto_report_akcipher rakcipher;
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strncpy(rakcipher.type, "akcipher", sizeof(rakcipher.type));
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if (nla_put(skb, CRYPTOCFGA_REPORT_AKCIPHER,
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sizeof(struct crypto_report_akcipher), &rakcipher))
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goto nla_put_failure;
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return 0;
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nla_put_failure:
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return -EMSGSIZE;
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}
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static int crypto_report_one(struct crypto_alg *alg,
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struct crypto_user_alg *ualg, struct sk_buff *skb)
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{
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strncpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name));
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strncpy(ualg->cru_driver_name, alg->cra_driver_name,
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sizeof(ualg->cru_driver_name));
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strncpy(ualg->cru_module_name, module_name(alg->cra_module),
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sizeof(ualg->cru_module_name));
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ualg->cru_type = 0;
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ualg->cru_mask = 0;
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ualg->cru_flags = alg->cra_flags;
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ualg->cru_refcnt = atomic_read(&alg->cra_refcnt);
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if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority))
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goto nla_put_failure;
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if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
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struct crypto_report_larval rl;
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strncpy(rl.type, "larval", sizeof(rl.type));
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if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL,
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sizeof(struct crypto_report_larval), &rl))
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goto nla_put_failure;
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goto out;
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}
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if (alg->cra_type && alg->cra_type->report) {
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if (alg->cra_type->report(skb, alg))
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goto nla_put_failure;
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goto out;
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}
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switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) {
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case CRYPTO_ALG_TYPE_CIPHER:
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if (crypto_report_cipher(skb, alg))
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goto nla_put_failure;
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break;
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case CRYPTO_ALG_TYPE_COMPRESS:
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if (crypto_report_comp(skb, alg))
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goto nla_put_failure;
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break;
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case CRYPTO_ALG_TYPE_AKCIPHER:
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if (crypto_report_akcipher(skb, alg))
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goto nla_put_failure;
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break;
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}
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out:
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return 0;
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nla_put_failure:
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return -EMSGSIZE;
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}
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static int crypto_report_alg(struct crypto_alg *alg,
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struct crypto_dump_info *info)
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{
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struct sk_buff *in_skb = info->in_skb;
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struct sk_buff *skb = info->out_skb;
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struct nlmsghdr *nlh;
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struct crypto_user_alg *ualg;
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int err = 0;
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nlh = nlmsg_put(skb, NETLINK_CB(in_skb).portid, info->nlmsg_seq,
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CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags);
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if (!nlh) {
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err = -EMSGSIZE;
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goto out;
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}
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ualg = nlmsg_data(nlh);
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err = crypto_report_one(alg, ualg, skb);
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if (err) {
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nlmsg_cancel(skb, nlh);
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goto out;
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}
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nlmsg_end(skb, nlh);
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out:
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return err;
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}
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static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
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struct nlattr **attrs)
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{
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struct crypto_user_alg *p = nlmsg_data(in_nlh);
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struct crypto_alg *alg;
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struct sk_buff *skb;
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struct crypto_dump_info info;
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int err;
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if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
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return -EINVAL;
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alg = crypto_alg_match(p, 0);
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if (!alg)
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return -ENOENT;
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err = -ENOMEM;
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skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
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if (!skb)
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goto drop_alg;
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info.in_skb = in_skb;
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info.out_skb = skb;
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info.nlmsg_seq = in_nlh->nlmsg_seq;
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info.nlmsg_flags = 0;
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err = crypto_report_alg(alg, &info);
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drop_alg:
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crypto_mod_put(alg);
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if (err)
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return err;
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return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
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}
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static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb)
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{
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struct crypto_alg *alg;
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struct crypto_dump_info info;
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int err;
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if (cb->args[0])
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goto out;
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cb->args[0] = 1;
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info.in_skb = cb->skb;
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info.out_skb = skb;
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info.nlmsg_seq = cb->nlh->nlmsg_seq;
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info.nlmsg_flags = NLM_F_MULTI;
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list_for_each_entry(alg, &crypto_alg_list, cra_list) {
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err = crypto_report_alg(alg, &info);
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if (err)
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goto out_err;
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}
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out:
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return skb->len;
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out_err:
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return err;
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}
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static int crypto_dump_report_done(struct netlink_callback *cb)
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{
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return 0;
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}
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static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
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struct nlattr **attrs)
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{
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struct crypto_alg *alg;
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struct crypto_user_alg *p = nlmsg_data(nlh);
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struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
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LIST_HEAD(list);
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if (!netlink_capable(skb, CAP_NET_ADMIN))
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return -EPERM;
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if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
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return -EINVAL;
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if (priority && !strlen(p->cru_driver_name))
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return -EINVAL;
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alg = crypto_alg_match(p, 1);
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if (!alg)
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return -ENOENT;
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down_write(&crypto_alg_sem);
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crypto_remove_spawns(alg, &list, NULL);
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if (priority)
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alg->cra_priority = nla_get_u32(priority);
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up_write(&crypto_alg_sem);
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crypto_mod_put(alg);
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crypto_remove_final(&list);
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return 0;
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}
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static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
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struct nlattr **attrs)
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{
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struct crypto_alg *alg;
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struct crypto_user_alg *p = nlmsg_data(nlh);
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int err;
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if (!netlink_capable(skb, CAP_NET_ADMIN))
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return -EPERM;
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if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
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return -EINVAL;
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alg = crypto_alg_match(p, 1);
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if (!alg)
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return -ENOENT;
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/* We can not unregister core algorithms such as aes-generic.
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* We would loose the reference in the crypto_alg_list to this algorithm
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* if we try to unregister. Unregistering such an algorithm without
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* removing the module is not possible, so we restrict to crypto
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* instances that are build from templates. */
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err = -EINVAL;
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if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
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goto drop_alg;
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err = -EBUSY;
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if (atomic_read(&alg->cra_refcnt) > 2)
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goto drop_alg;
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err = crypto_unregister_instance((struct crypto_instance *)alg);
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drop_alg:
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crypto_mod_put(alg);
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return err;
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}
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static struct crypto_alg *crypto_user_skcipher_alg(const char *name, u32 type,
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u32 mask)
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{
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int err;
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struct crypto_alg *alg;
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type = crypto_skcipher_type(type);
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mask = crypto_skcipher_mask(mask);
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for (;;) {
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alg = crypto_lookup_skcipher(name, type, mask);
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if (!IS_ERR(alg))
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return alg;
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err = PTR_ERR(alg);
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if (err != -EAGAIN)
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break;
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if (signal_pending(current)) {
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err = -EINTR;
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break;
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}
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}
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return ERR_PTR(err);
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}
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static struct crypto_alg *crypto_user_aead_alg(const char *name, u32 type,
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u32 mask)
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{
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int err;
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struct crypto_alg *alg;
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type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
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type |= CRYPTO_ALG_TYPE_AEAD;
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mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
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mask |= CRYPTO_ALG_TYPE_MASK;
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for (;;) {
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alg = crypto_lookup_aead(name, type, mask);
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if (!IS_ERR(alg))
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return alg;
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err = PTR_ERR(alg);
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if (err != -EAGAIN)
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break;
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if (signal_pending(current)) {
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err = -EINTR;
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break;
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}
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}
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return ERR_PTR(err);
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}
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static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
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struct nlattr **attrs)
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{
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int exact = 0;
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const char *name;
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struct crypto_alg *alg;
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struct crypto_user_alg *p = nlmsg_data(nlh);
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struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
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if (!netlink_capable(skb, CAP_NET_ADMIN))
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return -EPERM;
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if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
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return -EINVAL;
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if (strlen(p->cru_driver_name))
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exact = 1;
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if (priority && !exact)
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return -EINVAL;
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alg = crypto_alg_match(p, exact);
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if (alg) {
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crypto_mod_put(alg);
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return -EEXIST;
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}
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if (strlen(p->cru_driver_name))
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name = p->cru_driver_name;
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else
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name = p->cru_name;
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switch (p->cru_type & p->cru_mask & CRYPTO_ALG_TYPE_MASK) {
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case CRYPTO_ALG_TYPE_AEAD:
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alg = crypto_user_aead_alg(name, p->cru_type, p->cru_mask);
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break;
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case CRYPTO_ALG_TYPE_GIVCIPHER:
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case CRYPTO_ALG_TYPE_BLKCIPHER:
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case CRYPTO_ALG_TYPE_ABLKCIPHER:
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alg = crypto_user_skcipher_alg(name, p->cru_type, p->cru_mask);
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break;
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default:
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alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);
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}
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if (IS_ERR(alg))
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return PTR_ERR(alg);
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down_write(&crypto_alg_sem);
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if (priority)
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alg->cra_priority = nla_get_u32(priority);
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up_write(&crypto_alg_sem);
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crypto_mod_put(alg);
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return 0;
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}
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static int crypto_del_rng(struct sk_buff *skb, struct nlmsghdr *nlh,
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struct nlattr **attrs)
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{
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if (!netlink_capable(skb, CAP_NET_ADMIN))
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return -EPERM;
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return crypto_del_default_rng();
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}
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#define MSGSIZE(type) sizeof(struct type)
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static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = {
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[CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
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[CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
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[CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
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[CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = 0,
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};
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static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = {
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[CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32},
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};
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#undef MSGSIZE
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static const struct crypto_link {
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int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
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int (*dump)(struct sk_buff *, struct netlink_callback *);
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int (*done)(struct netlink_callback *);
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} crypto_dispatch[CRYPTO_NR_MSGTYPES] = {
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[CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},
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[CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},
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[CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},
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[CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report,
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.dump = crypto_dump_report,
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.done = crypto_dump_report_done},
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[CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = { .doit = crypto_del_rng },
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};
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static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
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{
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struct nlattr *attrs[CRYPTOCFGA_MAX+1];
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const struct crypto_link *link;
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int type, err;
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|
|
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;
|
|
u16 dump_alloc = 0;
|
|
|
|
if (link->dump == NULL)
|
|
return -EINVAL;
|
|
|
|
list_for_each_entry(alg, &crypto_alg_list, cra_list)
|
|
dump_alloc += CRYPTO_REPORT_MAXSIZE;
|
|
|
|
{
|
|
struct netlink_dump_control c = {
|
|
.dump = link->dump,
|
|
.done = link->done,
|
|
.min_dump_alloc = dump_alloc,
|
|
};
|
|
return netlink_dump_start(crypto_nlsk, skb, nlh, &c);
|
|
}
|
|
}
|
|
|
|
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)
|
|
{
|
|
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");
|