/*
 * Copyright (C) 2013 Intel Corporation
 *
 * Author:
 * Dmitry Kasatkin <dmitry.kasatkin@intel.com>
 *
 * 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, version 2 of the License.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/err.h>
#include <linux/ratelimit.h>
#include <linux/key-type.h>
#include <crypto/public_key.h>
#include <crypto/hash_info.h>
#include <keys/asymmetric-type.h>
#include <keys/system_keyring.h>

#include "integrity.h"

/*
 * Request an asymmetric key.
 */
static struct key *request_asymmetric_key(struct key *keyring, uint32_t keyid)
{
	struct key *key;
	char name[12];

	sprintf(name, "id:%08x", keyid);

	pr_debug("key search: \"%s\"\n", name);

	key = get_ima_blacklist_keyring();
	if (key) {
		key_ref_t kref;

		kref = keyring_search(make_key_ref(key, 1),
				     &key_type_asymmetric, name);
		if (!IS_ERR(kref)) {
			pr_err("Key '%s' is in ima_blacklist_keyring\n", name);
			return ERR_PTR(-EKEYREJECTED);
		}
	}

	if (keyring) {
		/* search in specific keyring */
		key_ref_t kref;

		kref = keyring_search(make_key_ref(keyring, 1),
				      &key_type_asymmetric, name);
		if (IS_ERR(kref))
			key = ERR_CAST(kref);
		else
			key = key_ref_to_ptr(kref);
	} else {
		key = request_key(&key_type_asymmetric, name, NULL);
	}

	if (IS_ERR(key)) {
		pr_err_ratelimited("Request for unknown key '%s' err %ld\n",
				   name, PTR_ERR(key));
		switch (PTR_ERR(key)) {
			/* Hide some search errors */
		case -EACCES:
		case -ENOTDIR:
		case -EAGAIN:
			return ERR_PTR(-ENOKEY);
		default:
			return key;
		}
	}

	pr_debug("%s() = 0 [%x]\n", __func__, key_serial(key));

	return key;
}

int asymmetric_verify(struct key *keyring, const char *sig,
		      int siglen, const char *data, int datalen)
{
	struct public_key_signature pks;
	struct signature_v2_hdr *hdr = (struct signature_v2_hdr *)sig;
	struct key *key;
	int ret = -ENOMEM;

	if (siglen <= sizeof(*hdr))
		return -EBADMSG;

	siglen -= sizeof(*hdr);

	if (siglen != __be16_to_cpu(hdr->sig_size))
		return -EBADMSG;

	if (hdr->hash_algo >= HASH_ALGO__LAST)
		return -ENOPKG;

	key = request_asymmetric_key(keyring, __be32_to_cpu(hdr->keyid));
	if (IS_ERR(key))
		return PTR_ERR(key);

	memset(&pks, 0, sizeof(pks));

	pks.pkey_algo = "rsa";
	pks.hash_algo = hash_algo_name[hdr->hash_algo];
	pks.digest = (u8 *)data;
	pks.digest_size = datalen;
	pks.s = hdr->sig;
	pks.s_size = siglen;
	ret = verify_signature(key, &pks);
	key_put(key);
	pr_debug("%s() = %d\n", __func__, ret);
	return ret;
}
/table>
<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?id=99421c1cb27fb837e93b517036fab4500fe39de5'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include?id=99421c1cb27fb837e93b517036fab4500fe39de5'>include</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings?id=99421c1cb27fb837e93b517036fab4500fe39de5'>dt-bindings</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='99421c1cb27fb837e93b517036fab4500fe39de5'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-15 16:09:50 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-15 16:09:50 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings?id=99421c1cb27fb837e93b517036fab4500fe39de5'>99421c1cb27fb837e93b517036fab4500fe39de5</a> (<a href='/cgit.cgi/linux/net-next.git/patch/include/dt-bindings?id=99421c1cb27fb837e93b517036fab4500fe39de5'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=99421c1cb27fb837e93b517036fab4500fe39de5'>de5fc5bacb671223f389793ad643cebe520bc292</a> /<a href='/cgit.cgi/linux/net-next.git/tree/include/dt-bindings?id=99421c1cb27fb837e93b517036fab4500fe39de5'>include/dt-bindings</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings?id=c92816275674c1491ce228ee49aa030a5fa1be04'>c92816275674c1491ce228ee49aa030a5fa1be04</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/dt-bindings?id=99421c1cb27fb837e93b517036fab4500fe39de5&amp;id2=c92816275674c1491ce228ee49aa030a5fa1be04'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings?id=93362fa47fe98b62e4a34ab408c4a418432e7939'>93362fa47fe98b62e4a34ab408c4a418432e7939</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/dt-bindings?id=99421c1cb27fb837e93b517036fab4500fe39de5&amp;id2=93362fa47fe98b62e4a34ab408c4a418432e7939'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace</div><div class='commit-msg'>Pull namespace fixes from Eric Biederman:
 "This tree contains 4 fixes.

  The first is a fix for a race that can causes oopses under the right
  circumstances, and that someone just recently encountered.

  Past that are several small trivial correct fixes. A real issue that
  was blocking development of an out of tree driver, but does not appear
  to have caused any actual problems for in-tree code. A potential
  deadlock that was reported by lockdep. And a deadlock people have
  experienced and took the time to track down caused by a cleanup that
  removed the code to drop a reference count"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  sysctl: Drop reference added by grab_header in proc_sys_readdir
  pid: fix lockdep deadlock warning due to ucount_lock
  libfs: Modify mount_pseudo_xattr to be clear it is not a userspace mount
  mnt: Protect the mountpoint hashtable with mount_lock
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=99421c1cb27fb837e93b517036fab4500fe39de5'>Diffstat</a> (limited to 'include/dt-bindings')</div><table summary='diffstat' class='diffstat'>