[PATCH 19/36] Bluetooth: SMP: Use new AES library API

From: Eric Biggers
Date: Mon Jan 05 2026 - 00:24:13 EST


Switch from the old AES library functions (which use struct
crypto_aes_ctx) to the new ones (which use struct aes_enckey). This
eliminates the unnecessary computation and caching of the decryption
round keys. The new AES en/decryption functions are also much faster
and use AES instructions when supported by the CPU.

Note: aes_encrypt_new() will be renamed to aes_encrypt() once all
callers of the old aes_encrypt() have been updated.

Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
---
net/bluetooth/smp.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index 3a1ce04a7a53..69007e510177 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -372,36 +372,36 @@ static int smp_h7(struct crypto_shash *tfm_cmac, const u8 w[16],
* s1 and ah.
*/

static int smp_e(const u8 *k, u8 *r)
{
- struct crypto_aes_ctx ctx;
+ struct aes_enckey aes;
uint8_t tmp[16], data[16];
int err;

SMP_DBG("k %16phN r %16phN", k, r);

/* The most significant octet of key corresponds to k[0] */
swap_buf(k, tmp, 16);

- err = aes_expandkey(&ctx, tmp, 16);
+ err = aes_prepareenckey(&aes, tmp, 16);
if (err) {
BT_ERR("cipher setkey failed: %d", err);
return err;
}

/* Most significant octet of plaintextData corresponds to data[0] */
swap_buf(r, data, 16);

- aes_encrypt(&ctx, data, data);
+ aes_encrypt_new(&aes, data, data);

/* Most significant octet of encryptedData corresponds to data[0] */
swap_buf(data, r, 16);

SMP_DBG("r %16phN", r);

- memzero_explicit(&ctx, sizeof(ctx));
+ memzero_explicit(&aes, sizeof(aes));
return err;
}

static int smp_c1(const u8 k[16],
const u8 r[16], const u8 preq[7], const u8 pres[7], u8 _iat,
--
2.52.0