Commit 6cec0b61 authored by Ilya Dryomov's avatar Ilya Dryomov
Browse files

libceph: introduce ceph_crypto_key_prepare() 



In preparation for bringing in a new encryption scheme/key type,
decouple decoding or cloning the key from allocating required crypto
API objects and setting them up.  The rationale is that a) in some
cases a shallow clone is sufficient and b) ceph_crypto_key_prepare()
may grow additional parameters that would be inconvenient to provide
at the point the key is originally decoded.

Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent 0ee8bccf

net/ceph/auth_x.c

+20 −6
Original line number Diff line number Diff line
@@ -221,6 +221,10 @@ static int process_one_ticket(struct ceph_auth_client *ac, 
	if (ret)

		goto out;



	ret = ceph_crypto_key_prepare(&new_session_key);

	if (ret)

		goto out;



	ceph_decode_need(&dp, dend, sizeof(struct ceph_timespec), bad);

	ceph_decode_timespec64(&validity, dp);

	dp += sizeof(struct ceph_timespec);
@@ -380,6 +384,10 @@ static int ceph_x_build_authorizer(struct ceph_auth_client *ac, 
	if (ret)

		goto out_au;



	ret = ceph_crypto_key_prepare(&au->session_key);

	if (ret)

		goto out_au;



	maxlen = sizeof(*msg_a) + ticket_blob_len +

		ceph_x_encrypt_buflen(&au->session_key, sizeof(*msg_b));

	dout("  need len %d\n", maxlen);
@@ -1106,21 +1114,26 @@ int ceph_x_init(struct ceph_auth_client *ac) 
	int ret;



	dout("ceph_x_init %p\n", ac);

	ret = -ENOMEM;

	xi = kzalloc(sizeof(*xi), GFP_NOFS);

	if (!xi)

		goto out;

		return -ENOMEM;



	ret = -EINVAL;

	if (!ac->key) {

		pr_err("no secret set (for auth_x protocol)\n");

		goto out_nomem;

		goto err_xi;

	}



	ret = ceph_crypto_key_clone(&xi->secret, ac->key);

	if (ret < 0) {

		pr_err("cannot clone key: %d\n", ret);

		goto out_nomem;

		goto err_xi;

	}



	ret = ceph_crypto_key_prepare(&xi->secret);

	if (ret) {

		pr_err("cannot prepare key: %d\n", ret);

		goto err_secret;

	}



	xi->starting = true;
@@ -1131,8 +1144,9 @@ int ceph_x_init(struct ceph_auth_client *ac) 
	ac->ops = &ceph_x_ops;

	return 0;



out_nomem:

err_secret:

	ceph_crypto_key_destroy(&xi->secret);

err_xi:

	kfree(xi);

out:

	return ret;

}

net/ceph/crypto.c

+35 −36
Original line number Diff line number Diff line
@@ -16,65 +16,61 @@ 
#include <linux/ceph/decode.h>

#include "crypto.h"



/*

 * Set ->key and ->tfm.  The rest of the key should be filled in before

 * this function is called.

 */

static int set_secret(struct ceph_crypto_key *key, void *buf)

static int set_aes_tfm(struct ceph_crypto_key *key)

{

	unsigned int noio_flag;

	int ret;



	key->key = NULL;

	key->tfm = NULL;



	switch (key->type) {

	case CEPH_CRYPTO_NONE:

		return 0; /* nothing to do */

	case CEPH_CRYPTO_AES:

		break;

	default:

		return -ENOTSUPP;

	}



	key->key = kmemdup(buf, key->len, GFP_NOIO);

	if (!key->key) {

		ret = -ENOMEM;

		goto fail;

	}



	/* crypto_alloc_sync_skcipher() allocates with GFP_KERNEL */

	noio_flag = memalloc_noio_save();

	key->tfm = crypto_alloc_sync_skcipher("cbc(aes)", 0, 0);

	memalloc_noio_restore(noio_flag);

	if (IS_ERR(key->tfm)) {

		ret = PTR_ERR(key->tfm);

		key->tfm = NULL;

		goto fail;

		return ret;

	}



	ret = crypto_sync_skcipher_setkey(key->tfm, key->key, key->len);

	if (ret)

		goto fail;

		return ret;



	return 0;

}



fail:

	ceph_crypto_key_destroy(key);

	return ret;

int ceph_crypto_key_prepare(struct ceph_crypto_key *key)

{

	switch (key->type) {

	case CEPH_CRYPTO_NONE:

		return 0; /* nothing to do */

	case CEPH_CRYPTO_AES:

		return set_aes_tfm(key);

	default:

		return -ENOTSUPP;

	}

}



/*

 * @dst should be zeroed before this function is called.

 */

int ceph_crypto_key_clone(struct ceph_crypto_key *dst,

			  const struct ceph_crypto_key *src)

{

	memcpy(dst, src, sizeof(struct ceph_crypto_key));

	return set_secret(dst, src->key);

	dst->type = src->type;

	dst->created = src->created;

	dst->len = src->len;



	dst->key = kmemdup(src->key, src->len, GFP_NOIO);

	if (!dst->key)

		return -ENOMEM;



	return 0;

}



/*

 * @key should be zeroed before this function is called.

 */

int ceph_crypto_key_decode(struct ceph_crypto_key *key, void **p, void *end)

{

	int ret;



	ceph_decode_need(p, end, 2*sizeof(u16) + sizeof(key->created), bad);

	key->type = ceph_decode_16(p);

	ceph_decode_copy(p, &key->created, sizeof(key->created));
@@ -85,10 +81,13 @@ int ceph_crypto_key_decode(struct ceph_crypto_key *key, void **p, void *end) 
		return -EINVAL;

	}



	ret = set_secret(key, *p);

	key->key = kmemdup(*p, key->len, GFP_NOIO);

	if (!key->key)

		return -ENOMEM;



	memzero_explicit(*p, key->len);

	*p += key->len;

	return ret;

	return 0;



bad:

	dout("failed to decode crypto key\n");
@@ -322,7 +321,7 @@ static int ceph_key_preparse(struct key_preparsed_payload *prep) 
		goto err;



	ret = -ENOMEM;

	ckey = kmalloc(sizeof(*ckey), GFP_KERNEL);

	ckey = kzalloc(sizeof(*ckey), GFP_KERNEL);

	if (!ckey)

		goto err;

net/ceph/crypto.h

+1 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ struct ceph_crypto_key { 
	struct crypto_sync_skcipher *tfm;

};



int ceph_crypto_key_prepare(struct ceph_crypto_key *key);

int ceph_crypto_key_clone(struct ceph_crypto_key *dst,

			  const struct ceph_crypto_key *src);

int ceph_crypto_key_decode(struct ceph_crypto_key *key, void **p, void *end);