[PATCH BlueZ 01/15] shared/crypto: Add bt_crypto_gatt_hash

[Luiz Augusto von Dentz <luiz.dentz@gmail.com>]

From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

The bt_crypto_gatt_hash uses AES-CCM to create a hash with the contents
stored in the iovec.

Note: The spec disregards the byte order so both the key, msg and res
are not swapped.
---
 src/shared/crypto.c | 31 +++++++++++++++++++++++++++++++
 src/shared/crypto.h |  3 +++
 2 files changed, 34 insertions(+)

diff --git a/src/shared/crypto.c b/src/shared/crypto.c
index ce0dcd638..5c5e1217d 100644
--- a/src/shared/crypto.c
+++ b/src/shared/crypto.c
@@ -688,3 +688,34 @@ bool bt_crypto_h6(struct bt_crypto *crypto, const uint8_t w[16],
 
 	return true;
 }
+
+bool bt_crypto_gatt_hash(struct bt_crypto *crypto, struct iovec *iov,
+				size_t iov_len, uint8_t res[16])
+{
+	const uint8_t key[16] = {};
+	ssize_t len;
+	int fd;
+
+	if (!crypto)
+		return false;
+
+	fd = alg_new(crypto->cmac_aes, key, 16);
+	if (fd < 0)
+		return false;
+
+	len = writev(fd, iov, iov_len);
+	if (len < 0) {
+		close(fd);
+		return false;
+	}
+
+	len = read(fd, res, 16);
+	if (len < 0) {
+		close(fd);
+		return false;
+	}
+
+	close(fd);
+
+	return true;
+}
diff --git a/src/shared/crypto.h b/src/shared/crypto.h
index 1e1b4836d..c58d2e104 100644
--- a/src/shared/crypto.h
+++ b/src/shared/crypto.h
@@ -23,6 +23,7 @@
 
 #include <stdbool.h>
 #include <stdint.h>
+#include <sys/uio.h>
 
 struct bt_crypto;
 
@@ -61,3 +62,5 @@ bool bt_crypto_h6(struct bt_crypto *crypto, const uint8_t w[16],
 bool bt_crypto_sign_att(struct bt_crypto *crypto, const uint8_t key[16],
 				const uint8_t *m, uint16_t m_len,
 				uint32_t sign_cnt, uint8_t signature[12]);
+bool bt_crypto_gatt_hash(struct bt_crypto *crypto, struct iovec *iov,
+				size_t iov_len, uint8_t res[16]);
-- 
2.17.2