Bluetooth: let the crypto subsystem generate the ecc privkey

That Bluetooth SMP knows about the private key is pointless, since the
detection of debug key usage is actually via the public key portion.
With this patch, the Bluetooth SMP will stop keeping a copy of the
ecdh private key and will let the crypto subsystem to generate and
handle the ecdh private key, potentially benefiting of hardware
ecc private key generation and retention.

The loop that tries to generate a correct private key is now removed and
we trust the crypto subsystem to generate a correct private key. This
backup logic should be done in crypto, if really needed.

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

1 files changed, 11 insertions, 3 deletions

diff --git a/net/bluetooth/selftest.c b/net/bluetooth/selftest.c
index ce99648ed870..2d1519d0affa 100644
--- a/net/bluetooth/selftest.c
+++ b/net/bluetooth/selftest.c
@@ -152,11 +152,11 @@ static int __init test_ecdh_sample(struct crypto_kpp *tfm, const u8 priv_a[32],
         dhkey_a = &tmp[0];
         dhkey_b = &tmp[32];
 
-        ret = compute_ecdh_secret(tfm, pub_b, priv_a, dhkey_a);
+        ret = set_ecdh_privkey(tfm, priv_a);
         if (ret)
                 goto out;
 
-        ret = compute_ecdh_secret(tfm, pub_a, priv_b, dhkey_b);
+        ret = compute_ecdh_secret(tfm, pub_b, dhkey_a);
         if (ret)
                 goto out;
 
@@ -165,9 +165,17 @@ static int __init test_ecdh_sample(struct crypto_kpp *tfm, const u8 priv_a[32],
                 goto out;
         }
 
+        ret = set_ecdh_privkey(tfm, priv_b);
+        if (ret)
+                goto out;
+
+        ret = compute_ecdh_secret(tfm, pub_a, dhkey_b);
+        if (ret)
+                goto out;
+
         if (memcmp(dhkey_b, dhkey, 32))
                 ret = -EINVAL;
-
+        /* fall through*/
 out:
         kfree(tmp);
         return ret;