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Commit a4770e11 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Marcel Holtmann
Browse files

Bluetooth: Switch SMP to crypto_cipher_encrypt_one() 



SMP does ECB crypto on stack buffers.  This is complicated and
fragile, and it will not work if the stack is virtually allocated.

Switch to the crypto_cipher interface, which is simpler and safer.

Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Acked-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Acked-by: default avatarJohan Hedberg <johan.hedberg@intel.com>
Tested-by: default avatarJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
parent a90a6e55

net/bluetooth/smp.c

+28 −39
Original line number Diff line number Diff line
@@ -22,9 +22,9 @@ 


#include <linux/debugfs.h>

#include <linux/scatterlist.h>

#include <linux/crypto.h>

#include <crypto/b128ops.h>

#include <crypto/hash.h>

#include <crypto/skcipher.h>



#include <net/bluetooth/bluetooth.h>

#include <net/bluetooth/hci_core.h>
@@ -88,7 +88,7 @@ struct smp_dev { 
	u8			min_key_size;

	u8			max_key_size;



	struct crypto_skcipher	*tfm_aes;

	struct crypto_cipher	*tfm_aes;

	struct crypto_shash	*tfm_cmac;

};
@@ -127,7 +127,7 @@ struct smp_chan { 
	u8			dhkey[32];

	u8			mackey[16];



	struct crypto_skcipher	*tfm_aes;

	struct crypto_cipher	*tfm_aes;

	struct crypto_shash	*tfm_cmac;

};
@@ -361,10 +361,8 @@ static int smp_h6(struct crypto_shash *tfm_cmac, const u8 w[16], 
 * s1 and ah.

 */



static int smp_e(struct crypto_skcipher *tfm, const u8 *k, u8 *r)

static int smp_e(struct crypto_cipher *tfm, const u8 *k, u8 *r)

{

	SKCIPHER_REQUEST_ON_STACK(req, tfm);

	struct scatterlist sg;

	uint8_t tmp[16], data[16];

	int err;
@@ -378,7 +376,7 @@ static int smp_e(struct crypto_skcipher *tfm, const u8 *k, u8 *r) 
	/* The most significant octet of key corresponds to k[0] */

	swap_buf(k, tmp, 16);



	err = crypto_skcipher_setkey(tfm, tmp, 16);

	err = crypto_cipher_setkey(tfm, tmp, 16);

	if (err) {

		BT_ERR("cipher setkey failed: %d", err);

		return err;
@@ -387,16 +385,7 @@ static int smp_e(struct crypto_skcipher *tfm, const u8 *k, u8 *r) 
	/* Most significant octet of plaintextData corresponds to data[0] */

	swap_buf(r, data, 16);



	sg_init_one(&sg, data, 16);



	skcipher_request_set_tfm(req, tfm);

	skcipher_request_set_callback(req, 0, NULL, NULL);

	skcipher_request_set_crypt(req, &sg, &sg, 16, NULL);



	err = crypto_skcipher_encrypt(req);

	skcipher_request_zero(req);

	if (err)

		BT_ERR("Encrypt data error %d", err);

	crypto_cipher_encrypt_one(tfm, data, data);



	/* Most significant octet of encryptedData corresponds to data[0] */

	swap_buf(data, r, 16);
@@ -406,7 +395,7 @@ static int smp_e(struct crypto_skcipher *tfm, const u8 *k, u8 *r) 
	return err;

}



static int smp_c1(struct crypto_skcipher *tfm_aes, const u8 k[16],

static int smp_c1(struct crypto_cipher *tfm_aes, const u8 k[16],

		  const u8 r[16], const u8 preq[7], const u8 pres[7], u8 _iat,

		  const bdaddr_t *ia, u8 _rat, const bdaddr_t *ra, u8 res[16])

{
@@ -455,7 +444,7 @@ static int smp_c1(struct crypto_skcipher *tfm_aes, const u8 k[16], 
	return err;

}



static int smp_s1(struct crypto_skcipher *tfm_aes, const u8 k[16],

static int smp_s1(struct crypto_cipher *tfm_aes, const u8 k[16],

		  const u8 r1[16], const u8 r2[16], u8 _r[16])

{

	int err;
@@ -471,7 +460,7 @@ static int smp_s1(struct crypto_skcipher *tfm_aes, const u8 k[16], 
	return err;

}



static int smp_ah(struct crypto_skcipher *tfm, const u8 irk[16],

static int smp_ah(struct crypto_cipher *tfm, const u8 irk[16],

		  const u8 r[3], u8 res[3])

{

	u8 _res[16];
@@ -759,7 +748,7 @@ static void smp_chan_destroy(struct l2cap_conn *conn) 
	kzfree(smp->slave_csrk);

	kzfree(smp->link_key);



	crypto_free_skcipher(smp->tfm_aes);

	crypto_free_cipher(smp->tfm_aes);

	crypto_free_shash(smp->tfm_cmac);



	/* Ensure that we don't leave any debug key around if debug key
@@ -1359,9 +1348,9 @@ static struct smp_chan *smp_chan_create(struct l2cap_conn *conn) 
	if (!smp)

		return NULL;



	smp->tfm_aes = crypto_alloc_skcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);

	smp->tfm_aes = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);

	if (IS_ERR(smp->tfm_aes)) {

		BT_ERR("Unable to create ECB crypto context");

		BT_ERR("Unable to create AES crypto context");

		kzfree(smp);

		return NULL;

	}
@@ -1369,7 +1358,7 @@ static struct smp_chan *smp_chan_create(struct l2cap_conn *conn) 
	smp->tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);

	if (IS_ERR(smp->tfm_cmac)) {

		BT_ERR("Unable to create CMAC crypto context");

		crypto_free_skcipher(smp->tfm_aes);

		crypto_free_cipher(smp->tfm_aes);

		kzfree(smp);

		return NULL;

	}
@@ -3120,7 +3109,7 @@ static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid) 
{

	struct l2cap_chan *chan;

	struct smp_dev *smp;

	struct crypto_skcipher *tfm_aes;

	struct crypto_cipher *tfm_aes;

	struct crypto_shash *tfm_cmac;



	if (cid == L2CAP_CID_SMP_BREDR) {
@@ -3132,9 +3121,9 @@ static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid) 
	if (!smp)

		return ERR_PTR(-ENOMEM);



	tfm_aes = crypto_alloc_skcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);

	tfm_aes = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);

	if (IS_ERR(tfm_aes)) {

		BT_ERR("Unable to create ECB crypto context");

		BT_ERR("Unable to create AES crypto context");

		kzfree(smp);

		return ERR_CAST(tfm_aes);

	}
@@ -3142,7 +3131,7 @@ static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid) 
	tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);

	if (IS_ERR(tfm_cmac)) {

		BT_ERR("Unable to create CMAC crypto context");

		crypto_free_skcipher(tfm_aes);

		crypto_free_cipher(tfm_aes);

		kzfree(smp);

		return ERR_CAST(tfm_cmac);

	}
@@ -3156,7 +3145,7 @@ static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid) 
	chan = l2cap_chan_create();

	if (!chan) {

		if (smp) {

			crypto_free_skcipher(smp->tfm_aes);

			crypto_free_cipher(smp->tfm_aes);

			crypto_free_shash(smp->tfm_cmac);

			kzfree(smp);

		}
@@ -3203,7 +3192,7 @@ static void smp_del_chan(struct l2cap_chan *chan) 
	smp = chan->data;

	if (smp) {

		chan->data = NULL;

		crypto_free_skcipher(smp->tfm_aes);

		crypto_free_cipher(smp->tfm_aes);

		crypto_free_shash(smp->tfm_cmac);

		kzfree(smp);

	}
@@ -3440,7 +3429,7 @@ void smp_unregister(struct hci_dev *hdev) 


#if IS_ENABLED(CONFIG_BT_SELFTEST_SMP)



static int __init test_ah(struct crypto_skcipher *tfm_aes)

static int __init test_ah(struct crypto_cipher *tfm_aes)

{

	const u8 irk[16] = {

			0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
@@ -3460,7 +3449,7 @@ static int __init test_ah(struct crypto_skcipher *tfm_aes) 
	return 0;

}



static int __init test_c1(struct crypto_skcipher *tfm_aes)

static int __init test_c1(struct crypto_cipher *tfm_aes)

{

	const u8 k[16] = {

			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
@@ -3490,7 +3479,7 @@ static int __init test_c1(struct crypto_skcipher *tfm_aes) 
	return 0;

}



static int __init test_s1(struct crypto_skcipher *tfm_aes)

static int __init test_s1(struct crypto_cipher *tfm_aes)

{

	const u8 k[16] = {

			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
@@ -3686,7 +3675,7 @@ static const struct file_operations test_smp_fops = { 
	.llseek		= default_llseek,

};



static int __init run_selftests(struct crypto_skcipher *tfm_aes,

static int __init run_selftests(struct crypto_cipher *tfm_aes,

				struct crypto_shash *tfm_cmac)

{

	ktime_t calltime, delta, rettime;
@@ -3764,27 +3753,27 @@ static int __init run_selftests(struct crypto_skcipher *tfm_aes, 


int __init bt_selftest_smp(void)

{

	struct crypto_skcipher *tfm_aes;

	struct crypto_cipher *tfm_aes;

	struct crypto_shash *tfm_cmac;

	int err;



	tfm_aes = crypto_alloc_skcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);

	tfm_aes = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);

	if (IS_ERR(tfm_aes)) {

		BT_ERR("Unable to create ECB crypto context");

		BT_ERR("Unable to create AES crypto context");

		return PTR_ERR(tfm_aes);

	}



	tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, CRYPTO_ALG_ASYNC);

	if (IS_ERR(tfm_cmac)) {

		BT_ERR("Unable to create CMAC crypto context");

		crypto_free_skcipher(tfm_aes);

		crypto_free_cipher(tfm_aes);

		return PTR_ERR(tfm_cmac);

	}



	err = run_selftests(tfm_aes, tfm_cmac);



	crypto_free_shash(tfm_cmac);

	crypto_free_skcipher(tfm_aes);

	crypto_free_cipher(tfm_aes);



	return err;

}