Bluetooth: Organize SMP crypto functions to logical sections

This patch organizes the various SMP crypto functions so that the LE SC
functions appear in one section and the legacy SMP functions in a
separate one.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/smp.c

@@ -141,6 +141,10 @@ static inline void swap_buf(const u8 *src, u8 *dst, size_t len)
 		dst[len - 1 - i] = src[i];
 }
 
+/* The following functions map to the LE SC SMP crypto functions
+ * AES-CMAC, f4, f5, f6, g2 and h6.
+ */
+
 static int aes_cmac(struct crypto_hash *tfm, const u8 k[16], const u8 *m,
 		    size_t len, u8 mac[16])
 {
@@ -325,6 +329,26 @@ static int smp_g2(struct crypto_hash *tfm_cmac, const u8 u[32], const u8 v[32],
 	return 0;
 }
 
+static int smp_h6(struct crypto_hash *tfm_cmac, const u8 w[16],
+		  const u8 key_id[4], u8 res[16])
+{
+	int err;
+
+	SMP_DBG("w %16phN key_id %4phN", w, key_id);
+
+	err = aes_cmac(tfm_cmac, w, key_id, 4, res);
+	if (err)
+		return err;
+
+	SMP_DBG("res %16phN", res);
+
+	return err;
+}
+
+/* The following functions map to the legacy SMP crypto functions e, c1,
+ * s1 and ah.
+ */
+
 static int smp_e(struct crypto_blkcipher *tfm, const u8 *k, u8 *r)
 {
 	struct blkcipher_desc desc;
@@ -364,18 +388,59 @@ static int smp_e(struct crypto_blkcipher *tfm, const u8 *k, u8 *r)
 	return err;
 }
 
-static int smp_h6(struct crypto_hash *tfm_cmac, const u8 w[16],
-		  const u8 key_id[4], u8 res[16])
+static int smp_c1(struct crypto_blkcipher *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])
 {
+	u8 p1[16], p2[16];
 	int err;
 
-	SMP_DBG("w %16phN key_id %4phN", w, key_id);
+	memset(p1, 0, 16);
 
-	err = aes_cmac(tfm_cmac, w, key_id, 4, res);
-	if (err)
+	/* p1 = pres || preq || _rat || _iat */
+	p1[0] = _iat;
+	p1[1] = _rat;
+	memcpy(p1 + 2, preq, 7);
+	memcpy(p1 + 9, pres, 7);
+
+	/* p2 = padding || ia || ra */
+	memcpy(p2, ra, 6);
+	memcpy(p2 + 6, ia, 6);
+	memset(p2 + 12, 0, 4);
+
+	/* res = r XOR p1 */
+	u128_xor((u128 *) res, (u128 *) r, (u128 *) p1);
+
+	/* res = e(k, res) */
+	err = smp_e(tfm_aes, k, res);
+	if (err) {
+		BT_ERR("Encrypt data error");
 		return err;
+	}
 
-	SMP_DBG("res %16phN", res);
+	/* res = res XOR p2 */
+	u128_xor((u128 *) res, (u128 *) res, (u128 *) p2);
+
+	/* res = e(k, res) */
+	err = smp_e(tfm_aes, k, res);
+	if (err)
+		BT_ERR("Encrypt data error");
+
+	return err;
+}
+
+static int smp_s1(struct crypto_blkcipher *tfm_aes, const u8 k[16],
+		  const u8 r1[16], const u8 r2[16], u8 _r[16])
+{
+	int err;
+
+	/* Just least significant octets from r1 and r2 are considered */
+	memcpy(_r, r2, 8);
+	memcpy(_r + 8, r1, 8);
+
+	err = smp_e(tfm_aes, k, _r);
+	if (err)
+		BT_ERR("Encrypt data error");
 
 	return err;
 }
@@ -454,63 +519,6 @@ int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa)
 	return 0;
 }
 
-static int smp_c1(struct crypto_blkcipher *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])
-{
-	u8 p1[16], p2[16];
-	int err;
-
-	memset(p1, 0, 16);
-
-	/* p1 = pres || preq || _rat || _iat */
-	p1[0] = _iat;
-	p1[1] = _rat;
-	memcpy(p1 + 2, preq, 7);
-	memcpy(p1 + 9, pres, 7);
-
-	/* p2 = padding || ia || ra */
-	memcpy(p2, ra, 6);
-	memcpy(p2 + 6, ia, 6);
-	memset(p2 + 12, 0, 4);
-
-	/* res = r XOR p1 */
-	u128_xor((u128 *) res, (u128 *) r, (u128 *) p1);
-
-	/* res = e(k, res) */
-	err = smp_e(tfm_aes, k, res);
-	if (err) {
-		BT_ERR("Encrypt data error");
-		return err;
-	}
-
-	/* res = res XOR p2 */
-	u128_xor((u128 *) res, (u128 *) res, (u128 *) p2);
-
-	/* res = e(k, res) */
-	err = smp_e(tfm_aes, k, res);
-	if (err)
-		BT_ERR("Encrypt data error");
-
-	return err;
-}
-
-static int smp_s1(struct crypto_blkcipher *tfm_aes, const u8 k[16],
-		  const u8 r1[16], const u8 r2[16], u8 _r[16])
-{
-	int err;
-
-	/* Just least significant octets from r1 and r2 are considered */
-	memcpy(_r, r2, 8);
-	memcpy(_r + 8, r1, 8);
-
-	err = smp_e(tfm_aes, k, _r);
-	if (err)
-		BT_ERR("Encrypt data error");
-
-	return err;
-}
-
 static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data)
 {
 	struct l2cap_chan *chan = conn->smp;