Bluetooth: move ecdh allocation outside of ecdh_helper

Before this change, a new crypto tfm was allocated, each time,
for both key generation and shared secret computation.

Allocate a single tfm for both cases.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 55 insertions, 13 deletions

diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index a0ef89772c36..31b64bc3cf16 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -26,6 +26,7 @@
 #include <crypto/algapi.h>
 #include <crypto/b128ops.h>
 #include <crypto/hash.h>
+#include <crypto/kpp.h>
 
 #include <net/bluetooth/bluetooth.h>
 #include <net/bluetooth/hci_core.h>
@@ -92,6 +93,7 @@ struct smp_dev {
 
 	struct crypto_cipher	*tfm_aes;
 	struct crypto_shash	*tfm_cmac;
+	struct crypto_kpp	*tfm_ecdh;
 };
 
 struct smp_chan {
@@ -131,6 +133,7 @@ struct smp_chan {
 
 	struct crypto_cipher	*tfm_aes;
 	struct crypto_shash	*tfm_cmac;
+	struct crypto_kpp	*tfm_ecdh;
 };
 
 /* These debug key values are defined in the SMP section of the core
@@ -574,7 +577,8 @@ int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16])
 			get_random_bytes(smp->local_sk, 32);
 
 			/* Generate local key pair for Secure Connections */
-			if (!generate_ecdh_keys(smp->local_pk, smp->local_sk))
+			if (!generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk,
+						smp->local_sk))
 				return -EIO;
 
 			/* This is unlikely, but we need to check that
@@ -771,6 +775,7 @@ static void smp_chan_destroy(struct l2cap_conn *conn)
 
 	crypto_free_cipher(smp->tfm_aes);
 	crypto_free_shash(smp->tfm_cmac);
+	crypto_free_kpp(smp->tfm_ecdh);
 
 	/* Ensure that we don't leave any debug key around if debug key
 	 * support hasn't been explicitly enabled.
@@ -1391,16 +1396,19 @@ static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
 	smp->tfm_aes = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
 	if (IS_ERR(smp->tfm_aes)) {
 		BT_ERR("Unable to create AES crypto context");
-		kzfree(smp);
-		return NULL;
+		goto zfree_smp;
 	}
 
 	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_cipher(smp->tfm_aes);
-		kzfree(smp);
-		return NULL;
+		goto free_cipher;
+	}
+
+	smp->tfm_ecdh = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0);
+	if (IS_ERR(smp->tfm_ecdh)) {
+		BT_ERR("Unable to create ECDH crypto context");
+		goto free_shash;
 	}
 
 	smp->conn = conn;
@@ -1413,6 +1421,14 @@ static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
 	hci_conn_hold(conn->hcon);
 
 	return smp;
+
+free_shash:
+	crypto_free_shash(smp->tfm_cmac);
+free_cipher:
+	crypto_free_cipher(smp->tfm_aes);
+zfree_smp:
+	kzfree(smp);
+	return NULL;
 }
 
 static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16])
@@ -1903,7 +1919,8 @@ static u8 sc_send_public_key(struct smp_chan *smp)
 			get_random_bytes(smp->local_sk, 32);
 
 			/* Generate local key pair for Secure Connections */
-			if (!generate_ecdh_keys(smp->local_pk, smp->local_sk))
+			if (!generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk,
+						smp->local_sk))
 				return SMP_UNSPECIFIED;
 
 			/* This is unlikely, but we need to check that
@@ -2677,7 +2694,8 @@ static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb)
 	SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk);
 	SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32);
 
-	if (!compute_ecdh_secret(smp->remote_pk, smp->local_sk, smp->dhkey))
+	if (!compute_ecdh_secret(smp->tfm_ecdh, smp->remote_pk, smp->local_sk,
+				 smp->dhkey))
 		return SMP_UNSPECIFIED;
 
 	SMP_DBG("DHKey %32phN", smp->dhkey);
@@ -3169,6 +3187,7 @@ static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid)
 	struct smp_dev *smp;
 	struct crypto_cipher *tfm_aes;
 	struct crypto_shash *tfm_cmac;
+	struct crypto_kpp *tfm_ecdh;
 
 	if (cid == L2CAP_CID_SMP_BREDR) {
 		smp = NULL;
@@ -3194,8 +3213,18 @@ static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid)
 		return ERR_CAST(tfm_cmac);
 	}
 
+	tfm_ecdh = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0);
+	if (IS_ERR(tfm_ecdh)) {
+		BT_ERR("Unable to create ECDH crypto context");
+		crypto_free_shash(tfm_cmac);
+		crypto_free_cipher(tfm_aes);
+		kzfree(smp);
+		return ERR_CAST(tfm_ecdh);
+	}
+
 	smp->tfm_aes = tfm_aes;
 	smp->tfm_cmac = tfm_cmac;
+	smp->tfm_ecdh = tfm_ecdh;
 	smp->min_key_size = SMP_MIN_ENC_KEY_SIZE;
 	smp->max_key_size = SMP_MAX_ENC_KEY_SIZE;
 
@@ -3205,6 +3234,7 @@ create_chan:
 		if (smp) {
 			crypto_free_cipher(smp->tfm_aes);
 			crypto_free_shash(smp->tfm_cmac);
+			crypto_free_kpp(smp->tfm_ecdh);
 			kzfree(smp);
 		}
 		return ERR_PTR(-ENOMEM);
@@ -3252,6 +3282,7 @@ static void smp_del_chan(struct l2cap_chan *chan)
 		chan->data = NULL;
 		crypto_free_cipher(smp->tfm_aes);
 		crypto_free_shash(smp->tfm_cmac);
+		crypto_free_kpp(smp->tfm_ecdh);
 		kzfree(smp);
 	}
 
@@ -3498,13 +3529,13 @@ static inline void swap_digits(u64 *in, u64 *out, unsigned int ndigits)
 		out[i] = __swab64(in[ndigits - 1 - i]);
 }
 
-static int __init test_debug_key(void)
+static int __init test_debug_key(struct crypto_kpp *tfm_ecdh)
 {
 	u8 pk[64], sk[32];
 
 	swap_digits((u64 *)debug_sk, (u64 *)sk, 4);
 
-	if (!generate_ecdh_keys(pk, sk))
+	if (!generate_ecdh_keys(tfm_ecdh, pk, sk))
 		return -EINVAL;
 
 	if (crypto_memneq(sk, debug_sk, 32))
@@ -3763,7 +3794,8 @@ static const struct file_operations test_smp_fops = {
 };
 
 static int __init run_selftests(struct crypto_cipher *tfm_aes,
-				struct crypto_shash *tfm_cmac)
+				struct crypto_shash *tfm_cmac,
+				struct crypto_kpp *tfm_ecdh)
 {
 	ktime_t calltime, delta, rettime;
 	unsigned long long duration;
@@ -3771,7 +3803,7 @@ static int __init run_selftests(struct crypto_cipher *tfm_aes,
 
 	calltime = ktime_get();
 
-	err = test_debug_key();
+	err = test_debug_key(tfm_ecdh);
 	if (err) {
 		BT_ERR("debug_key test failed");
 		goto done;
@@ -3848,6 +3880,7 @@ int __init bt_selftest_smp(void)
 {
 	struct crypto_cipher *tfm_aes;
 	struct crypto_shash *tfm_cmac;
+	struct crypto_kpp *tfm_ecdh;
 	int err;
 
 	tfm_aes = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
@@ -3863,10 +3896,19 @@ int __init bt_selftest_smp(void)
 		return PTR_ERR(tfm_cmac);
 	}
 
-	err = run_selftests(tfm_aes, tfm_cmac);
+	tfm_ecdh = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0);
+	if (IS_ERR(tfm_ecdh)) {
+		BT_ERR("Unable to create ECDH crypto context");
+		crypto_free_shash(tfm_cmac);
+		crypto_free_cipher(tfm_aes);
+		return PTR_ERR(tfm_ecdh);
+	}
+
+	err = run_selftests(tfm_aes, tfm_cmac, tfm_ecdh);
 
 	crypto_free_shash(tfm_cmac);
 	crypto_free_cipher(tfm_aes);
+	crypto_free_kpp(tfm_ecdh);
 
 	return err;
 }