[PATCH 17/43] misc/mei/hdcp: Prepare Session Key

Ramalingam C
2018-02-14T14:20:26Z

Request to ME to prepare the encrypted session key.

On Success, ME provides Encrypted session key. Functions populates
the HDCP2.2 authentication msg SKE_Send_Eks.

Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
---
drivers/misc/mei/mei_hdcp.c | 68 +++++++++++++++++++++++++++++++++++++++++++++
include/linux/mei_hdcp.h | 8 ++++++
2 files changed, 76 insertions(+)

diff --git a/drivers/misc/mei/mei_hdcp.c b/drivers/misc/mei/mei_hdcp.c
index 828dcce56b49..d4d009ebaf98 100644
--- a/drivers/misc/mei/mei_hdcp.c
+++ b/drivers/misc/mei/mei_hdcp.c
@@ -468,6 +468,74 @@ int mei_verify_lprime(struct mei_hdcp_data *data,
}
EXPORT_SYMBOL(mei_verify_lprime);

+/**
+ * mei_get_session_key:
+ * Function to prepare SKE_Send_Eks.
+ *
+ * @data : Intel HW specific Data
+ * @ske_data : Pointer for SKE_Send_Eks.
+ *
+ * Returns 0 on Success, <0 on Failure
+ */
+int mei_get_session_key(struct mei_hdcp_data *data,
+ struct hdcp2_ske_send_eks *ske_data)
+{
+ struct wired_cmd_get_session_key_in get_skey_in = { { 0 } };
+ struct wired_cmd_get_session_key_out get_skey_out = { { 0 } };
+ enum me_status status;
+ struct device *dev;
+ ssize_t byte;
+
+ if (!data || !ske_data)
+ return -EINVAL;
+
+ /* check for the mei_device enabled or not */
+ if (!mei_cldev_active_and_enabled(data->cldev))
+ return -ENODEV;
+
+ dev = &data->cldev->dev;
+
+ get_skey_in.header.api_version = HDCP_API_VERSION;
+ get_skey_in.header.command_id = WIRED_GET_SESSION_KEY;
+ get_skey_in.header.status = ME_HDCP_STATUS_SUCCESS;
+ get_skey_in.header.buffer_len = WIRED_CMD_BUF_LEN_GET_SESSION_KEY_IN;
+
+ get_skey_in.port.integrated_port_type = data->port_type;
+ get_skey_in.port.physical_port = data->port;
+
+ /* Request to ME */
+ byte = mei_cldev_send(data->cldev, (u8 *)&get_skey_in,
+ sizeof(get_skey_in));
+ if (byte < 0) {
+ dev_err(dev, "mei_cldev_send failed. %d\n", (int)byte);
+ return byte;
+ }
+
+ /* Response from ME */
+ byte = mei_cldev_recv(data->cldev, (u8 *)&get_skey_out,
+ sizeof(get_skey_out));
+
+ if (byte < 0) {
+ dev_err(dev, "mei_cldev_recv failed. %d\n", (int)byte);
+ return byte;
+ }
+
+ status = (enum me_status)get_skey_out.header.status;
+ if (status != ME_HDCP_STATUS_SUCCESS) {
+ dev_err(dev, "ME cmd 0x%08X failed. status: 0x%X\n",
+ WIRED_GET_SESSION_KEY, status);
+ return -1;
+ }
+
+ ske_data->msg_id = SKE_SEND_EKS;
+ memcpy(ske_data->e_dkey_ks, get_skey_out.e_dkey_ks,
+ sizeof(get_skey_out.e_dkey_ks));
+ memcpy(ske_data->riv, get_skey_out.r_iv,
+ sizeof(get_skey_out.r_iv));
+ return 0;
+}
+EXPORT_SYMBOL(mei_get_session_key);
+
static int mei_hdcp_probe(struct mei_cl_device *cldev,
const struct mei_cl_device_id *id)
{
diff --git a/include/linux/mei_hdcp.h b/include/linux/mei_hdcp.h
index d8c2b440cd81..193f23ba8fbc 100644
--- a/include/linux/mei_hdcp.h
+++ b/include/linux/mei_hdcp.h
@@ -119,6 +119,8 @@ int mei_initiate_locality_check(struct mei_hdcp_data *data,
struct hdcp2_lc_init *lc_init_data);
int mei_verify_lprime(struct mei_hdcp_data *data,
struct hdcp2_lc_send_lprime *rx_lprime);
+int mei_get_session_key(struct mei_hdcp_data *data,
+ struct hdcp2_ske_send_eks *ske_data);
#else
static inline
int mei_hdcp_cldev_get_reference(void *client_data,
@@ -172,5 +174,11 @@ int mei_verify_lprime(struct mei_hdcp_data *data,
{
return -ENODEV;
}
+static inline
+int mei_get_session_key(struct mei_hdcp_data *data,
+ struct hdcp2_ske_send_eks *ske_data)
+{
+ return -ENODEV;
+}
#endif /* defined (CONFIG_INTEL_MEI_HDCP) */
#endif /* defined (_LINUX_MEI_HDCP_H) */