[RESEND RFC PATCH 0/2] Bluetooth: let the crypto subsystem generate the ecc privkey

@@ -23,7 +23,6 @@
 #include "ecdh_helper.h"
 
 #include <linux/scatterlist.h>
-#include <crypto/kpp.h>
 #include <crypto/ecdh.h>
 
 struct ecdh_completion {

@@ -50,10 +49,9 @@ static inline void swap_digits(u64 *in, u64 *out, unsigned int ndigits)
 		out[i] = __swab64(in[ndigits - 1 - i]);
 }
 
-bool compute_ecdh_secret(const u8 public_key[64], const u8 private_key[32],
-			 u8 secret[32])
+bool compute_ecdh_secret(struct crypto_kpp *tfm, const u8 public_key[64],
+			 const u8 private_key[32], u8 secret[32])
 {
-	struct crypto_kpp *tfm;
 	struct kpp_request *req;
 	struct ecdh p;
 	struct ecdh_completion result;

@@ -66,16 +64,9 @@ bool compute_ecdh_secret(const u8 public_key[64], const u8 private_key[32],
 	if (!tmp)
 		return false;
 
-	tfm = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0);
-	if (IS_ERR(tfm)) {
-		pr_err("alg: kpp: Failed to load tfm for kpp: %ld\n",
-		       PTR_ERR(tfm));
-		goto free_tmp;
-	}
-
 	req = kpp_request_alloc(tfm, GFP_KERNEL);
 	if (!req)
-		goto free_kpp;
+		goto free_tmp;
 
 	init_completion(&result.completion);
 

@@ -126,16 +117,14 @@ bool compute_ecdh_secret(const u8 public_key[64], const u8 private_key[32],
 	kzfree(buf);
 free_req:
 	kpp_request_free(req);
-free_kpp:
-	crypto_free_kpp(tfm);
 free_tmp:
 	kfree(tmp);
 	return (err == 0);
 }
 
-bool generate_ecdh_keys(u8 public_key[64], u8 private_key[32])
+bool generate_ecdh_keys(struct crypto_kpp *tfm, u8 public_key[64],
+			u8 private_key[32])
 {
-	struct crypto_kpp *tfm;
 	struct kpp_request *req;
 	struct ecdh p;
 	struct ecdh_completion result;

@@ -150,16 +139,9 @@ bool generate_ecdh_keys(u8 public_key[64], u8 private_key[32])
 	if (!tmp)
 		return false;
 
-	tfm = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0);
-	if (IS_ERR(tfm)) {
-		pr_err("alg: kpp: Failed to load tfm for kpp: %ld\n",
-		       PTR_ERR(tfm));
-		goto free_tmp;
-	}
-
 	req = kpp_request_alloc(tfm, GFP_KERNEL);
 	if (!req)
-		goto free_kpp;
+		goto free_tmp;
 
 	init_completion(&result.completion);
 

@@ -218,8 +200,6 @@ bool generate_ecdh_keys(u8 public_key[64], u8 private_key[32])
 	kzfree(buf);
 free_req:
 	kpp_request_free(req);
-free_kpp:
-	crypto_free_kpp(tfm);
 free_tmp:
 	kfree(tmp);
 	return (err == 0);

@@ -20,8 +20,10 @@
  * COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
  * SOFTWARE IS DISCLAIMED.
  */
+#include <crypto/kpp.h>
 #include <linux/types.h>
 
-bool compute_ecdh_secret(const u8 pub_a[64], const u8 priv_b[32],
-			 u8 secret[32]);
-bool generate_ecdh_keys(u8 public_key[64], u8 private_key[32]);
+bool compute_ecdh_secret(struct crypto_kpp *tfm, const u8 pub_a[64],
+			 const u8 priv_b[32], u8 secret[32]);
+bool generate_ecdh_keys(struct crypto_kpp *tfm, u8 public_key[64],
+			u8 private_key[32]);

@@ -138,9 +138,9 @@ static const u8 dhkey_3[32] __initconst = {
 	0x7c, 0x1c, 0xf9, 0x49, 0xe6, 0xd7, 0xaa, 0x70,
 };
 
-static int __init test_ecdh_sample(const u8 priv_a[32], const u8 priv_b[32],
-				   const u8 pub_a[64], const u8 pub_b[64],
-				   const u8 dhkey[32])
+static int __init test_ecdh_sample(struct crypto_kpp *tfm, const u8 priv_a[32],
+				   const u8 priv_b[32], const u8 pub_a[64],
+				   const u8 pub_b[64], const u8 dhkey[32])
 {
 	u8 *tmp, *dhkey_a, *dhkey_b;
 	int ret = 0;

@@ -152,8 +152,8 @@ static int __init test_ecdh_sample(const u8 priv_a[32], const u8 priv_b[32],
 	dhkey_a = &tmp[0];
 	dhkey_b = &tmp[32];
 
-	compute_ecdh_secret(pub_b, priv_a, dhkey_a);
-	compute_ecdh_secret(pub_a, priv_b, dhkey_b);
+	compute_ecdh_secret(tfm, pub_b, priv_a, dhkey_a);
+	compute_ecdh_secret(tfm, pub_a, priv_b, dhkey_b);
 
 	if (memcmp(dhkey_a, dhkey, 32)) {
 		ret = -EINVAL;

@@ -185,30 +185,43 @@ static const struct file_operations test_ecdh_fops = {
 
 static int __init test_ecdh(void)
 {
+	struct crypto_kpp *tfm;
 	ktime_t calltime, delta, rettime;
 	unsigned long long duration;
 	int err;
 
 	calltime = ktime_get();
 
-	err = test_ecdh_sample(priv_a_1, priv_b_1, pub_a_1, pub_b_1, dhkey_1);
+	tfm = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0);
+	if (IS_ERR(tfm)) {
+		BT_ERR("Unable to create ECDH crypto context");
+		err = PTR_ERR(tfm);
+		goto done;
+	}
+
+	err = test_ecdh_sample(tfm, priv_a_1, priv_b_1, pub_a_1, pub_b_1,
+			       dhkey_1);
 	if (err) {
 		BT_ERR("ECDH sample 1 failed");
 		goto done;
 	}
 
-	err = test_ecdh_sample(priv_a_2, priv_b_2, pub_a_2, pub_b_2, dhkey_2);
+	err = test_ecdh_sample(tfm, priv_a_2, priv_b_2, pub_a_2, pub_b_2,
+			       dhkey_2);
 	if (err) {
 		BT_ERR("ECDH sample 2 failed");
 		goto done;
 	}
 
-	err = test_ecdh_sample(priv_a_3, priv_a_3, pub_a_3, pub_a_3, dhkey_3);
+	err = test_ecdh_sample(tfm, priv_a_3, priv_a_3, pub_a_3, pub_a_3,
+			       dhkey_3);
 	if (err) {
 		BT_ERR("ECDH sample 3 failed");
 		goto done;
 	}
 
+	crypto_free_kpp(tfm);
+
 	rettime = ktime_get();
 	delta = ktime_sub(rettime, calltime);
 	duration = (unsigned long long) ktime_to_ns(delta) >> 10;

@@ -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

@@ -2645,6 +2662,7 @@ static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb)
 	struct l2cap_chan *chan = conn->smp;
 	struct smp_chan *smp = chan->data;
 	struct hci_dev *hdev = hcon->hdev;
+	struct crypto_kpp *tfm;
 	struct smp_cmd_pairing_confirm cfm;
 	int err;
 

@@ -2677,7 +2695,16 @@ 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 (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) {
+		struct smp_dev *smp_dev = chan->data;
+
+		tfm = smp_dev->tfm_ecdh;
+	} else {
+		tfm = smp->tfm_ecdh;
+	}
+
+	if (!compute_ecdh_secret(tfm, smp->remote_pk, smp->local_sk,
+				 smp->dhkey))
 		return SMP_UNSPECIFIED;
 
 	SMP_DBG("DHKey %32phN", smp->dhkey);

@@ -3169,6 +3196,7 @@ 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 +3222,18 @@ 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 +3243,7 @@ static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid)
 		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 +3291,7 @@ 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 +3538,13 @@ 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 +3803,8 @@ 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 +3812,7 @@ 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 +3889,7 @@ 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 +3905,19 @@ 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;
 }

@@ -53,10 +53,10 @@ bool compute_ecdh_secret(struct crypto_kpp *tfm, const u8 public_key[64],
 			 const u8 private_key[32], u8 secret[32])
 {
 	struct kpp_request *req;
-	struct ecdh p;
+	struct ecdh p = {0};
 	struct ecdh_completion result;
 	struct scatterlist src, dst;
-	u8 *tmp, *buf;
+	u8 *tmp, *buf = NULL;
 	unsigned int buf_len;
 	int err = -ENOMEM;
 

@@ -70,25 +70,29 @@ bool compute_ecdh_secret(struct crypto_kpp *tfm, const u8 public_key[64],
 
 	init_completion(&result.completion);
 
-	/* Security Manager Protocol holds digits in litte-endian order
-	 * while ECC API expect big-endian data
-	 */
-	swap_digits((u64 *)private_key, (u64 *)tmp, 4);
-	p.key = (char *)tmp;
-	p.key_size = 32;
 	/* Set curve_id */
 	p.curve_id = ECC_CURVE_NIST_P256;
-	buf_len = crypto_ecdh_key_len(&p);
-	buf = kmalloc(buf_len, GFP_KERNEL);
-	if (!buf)
-		goto free_req;
 
-	crypto_ecdh_encode_key(buf, buf_len, &p);
+	if (private_key) {
+		/* Security Manager Protocol holds digits in little-endian order
+		 * while ECC API expect big-endian data.
+		 */
+		swap_digits((u64 *)private_key, (u64 *)tmp, 4);
+		p.key = (char *)tmp;
+		p.key_size = 32;
 
-	/* Set A private Key */
-	err = crypto_kpp_set_secret(tfm, (void *)buf, buf_len);
-	if (err)
-		goto free_all;
+		buf_len = crypto_ecdh_key_len(&p);
+		buf = kmalloc(buf_len, GFP_KERNEL);
+		if (!buf)
+			goto free_req;
+
+		crypto_ecdh_encode_key(buf, buf_len, &p);
+
+		/* Set A private Key */
+		err = crypto_kpp_set_secret(tfm, (void *)buf, buf_len);
+		if (err)
+			goto free_all;
+	}
 
 	swap_digits((u64 *)public_key, (u64 *)tmp, 4); /* x */
 	swap_digits((u64 *)&public_key[32], (u64 *)&tmp[32], 4); /* y */

@@ -126,14 +130,12 @@ bool generate_ecdh_keys(struct crypto_kpp *tfm, u8 public_key[64],
 			u8 private_key[32])
 {
 	struct kpp_request *req;
-	struct ecdh p;
+	struct ecdh p = {0};
 	struct ecdh_completion result;
 	struct scatterlist dst;
 	u8 *tmp, *buf;
 	unsigned int buf_len;
 	int err = -ENOMEM;
-	const unsigned short max_tries = 16;
-	unsigned short tries = 0;
 
 	tmp = kmalloc(64, GFP_KERNEL);
 	if (!tmp)

@@ -145,56 +147,48 @@ bool generate_ecdh_keys(struct crypto_kpp *tfm, u8 public_key[64],
 
 	init_completion(&result.completion);
 
+	/* Set private Key */
+	if (private_key) {
+		p.key = (char *)private_key;
+		p.key_size = 32;
+	}
+
 	/* Set curve_id */
 	p.curve_id = ECC_CURVE_NIST_P256;
-	p.key_size = 32;
 	buf_len = crypto_ecdh_key_len(&p);
 	buf = kmalloc(buf_len, GFP_KERNEL);
 	if (!buf)
 		goto free_req;
 
-	do {
-		if (tries++ >= max_tries)
-			goto free_all;
-
-		/* Set private Key */
-		p.key = (char *)private_key;
-		crypto_ecdh_encode_key(buf, buf_len, &p);
-		err = crypto_kpp_set_secret(tfm, buf, buf_len);
-		if (err)
-			goto free_all;
-
-		sg_init_one(&dst, tmp, 64);
-		kpp_request_set_input(req, NULL, 0);
-		kpp_request_set_output(req, &dst, 64);
-		kpp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
-					 ecdh_complete, &result);
-
-		err = crypto_kpp_generate_public_key(req);
-
-		if (err == -EINPROGRESS) {
-			wait_for_completion(&result.completion);
-			err = result.err;
-		}
+	crypto_ecdh_encode_key(buf, buf_len, &p);
+	err = crypto_kpp_set_secret(tfm, buf, buf_len);
+	if (err)
+		goto free_all;
 
-		/* Private key is not valid. Regenerate */
-		if (err == -EINVAL)
-			continue;
+	sg_init_one(&dst, tmp, 64);
+	kpp_request_set_input(req, NULL, 0);
+	kpp_request_set_output(req, &dst, 64);
+	kpp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
+				 ecdh_complete, &result);
 
-		if (err < 0)
-			goto free_all;
-		else
-			break;
+	err = crypto_kpp_generate_public_key(req);
 
-	} while (true);
+	if (err == -EINPROGRESS) {
+		wait_for_completion(&result.completion);
+		err = result.err;
+	}
+	if (err < 0)
+		goto free_all;
 
 	/* Keys are handed back in little endian as expected by Security
 	 * Manager Protocol
 	 */
 	swap_digits((u64 *)tmp, (u64 *)public_key, 4); /* x */
 	swap_digits((u64 *)&tmp[32], (u64 *)&public_key[32], 4); /* y */
-	swap_digits((u64 *)private_key, (u64 *)tmp, 4);
-	memcpy(private_key, tmp, 32);
+	if (private_key) {
+		swap_digits((u64 *)private_key, (u64 *)tmp, 4);
+		memcpy(private_key, tmp, 32);
+	}
 
 free_all:
 	kzfree(buf);

@@ -571,28 +571,16 @@ int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16])
 		memcpy(smp->local_pk, debug_pk, 64);
 		memcpy(smp->local_sk, debug_sk, 32);
 		smp->debug_key = true;
+		SMP_DBG("OOB Private Key:  %32phN", smp->local_sk);
 	} else {
-		while (true) {
-			/* Seed private key with random number */
-			get_random_bytes(smp->local_sk, 32);
-
-			/* Generate local key pair for Secure Connections */
-			if (!generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk,
-						smp->local_sk))
-				return -EIO;
-
-			/* This is unlikely, but we need to check that
-			 * we didn't accidentially generate a debug key.
-			 */
-			if (crypto_memneq(smp->local_sk, debug_sk, 32))
-				break;
-		}
+		/* Generate local key pair for Secure Connections */
+		if (!generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk, NULL))
+			return -EIO;
 		smp->debug_key = false;
 	}
 
 	SMP_DBG("OOB Public Key X: %32phN", smp->local_pk);
 	SMP_DBG("OOB Public Key Y: %32phN", smp->local_pk + 32);
-	SMP_DBG("OOB Private Key:  %32phN", smp->local_sk);
 
 	get_random_bytes(smp->local_rand, 16);
 

@@ -1899,11 +1887,13 @@ static u8 sc_send_public_key(struct smp_chan *smp)
 		smp_dev = chan->data;
 
 		memcpy(smp->local_pk, smp_dev->local_pk, 64);
-		memcpy(smp->local_sk, smp_dev->local_sk, 32);
 		memcpy(smp->lr, smp_dev->local_rand, 16);
 
-		if (smp_dev->debug_key)
+		if (smp_dev->debug_key) {
 			set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
+			memcpy(smp->local_sk, smp_dev->local_sk, 32);
+			SMP_DBG("Local Private Key:  %32phN", smp->local_sk);
+		}
 
 		goto done;
 	}

@@ -1913,28 +1903,16 @@ static u8 sc_send_public_key(struct smp_chan *smp)
 		memcpy(smp->local_pk, debug_pk, 64);
 		memcpy(smp->local_sk, debug_sk, 32);
 		set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
+		SMP_DBG("Local Private Key:  %32phN", smp->local_sk);
 	} else {
-		while (true) {
-			/* Seed private key with random number */
-			get_random_bytes(smp->local_sk, 32);
-
-			/* Generate local key pair for Secure Connections */
-			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
-			 * we didn't accidentially generate a debug key.
-			 */
-			if (crypto_memneq(smp->local_sk, debug_sk, 32))
-				break;
-		}
+		/* Generate local key pair for Secure Connections */
+		if (!generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk, NULL))
+			return SMP_UNSPECIFIED;
 	}
 
 done:
 	SMP_DBG("Local Public Key X: %32phN", smp->local_pk);
 	SMP_DBG("Local Public Key Y: %32phN", smp->local_pk + 32);
-	SMP_DBG("Local Private Key:  %32phN", smp->local_sk);
 
 	smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk);
 

@@ -2663,6 +2641,7 @@ static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb)
 	struct smp_chan *smp = chan->data;
 	struct hci_dev *hdev = hcon->hdev;
 	struct crypto_kpp *tfm;
+	const u8 *local_sk;
 	struct smp_cmd_pairing_confirm cfm;
 	int err;
 

@@ -2703,8 +2682,12 @@ static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb)
 		tfm = smp->tfm_ecdh;
 	}
 
-	if (!compute_ecdh_secret(tfm, smp->remote_pk, smp->local_sk,
-				 smp->dhkey))
+	if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS))
+		local_sk = smp->local_sk;
+	else
+		local_sk = NULL;
+
+	if (!compute_ecdh_secret(tfm, smp->remote_pk, local_sk, smp->dhkey))
 		return SMP_UNSPECIFIED;
 
 	SMP_DBG("DHKey %32phN", smp->dhkey);