[PATCH v6 26/35] misc/mei/hdcp: Verify Receiver Cert and prepare km

[Ramalingam C]

Requests for verification for receiver certification and also the
preparation for next AKE auth message with km.

On Success ME FW validate the HDCP2.2 receivers certificate and do the
revocation check on the receiver ID. AKE_Stored_Km will be prepared if
the receiver is already paired, else AKE_No_Stored_Km will be prepared.

Here AKE_Stored_Km and AKE_No_Stored_Km are HDCP2.2 protocol msgs.

v2:
  Rebased.
v3:
  cldev is passed as first parameter [Tomas]
  Redundant comments and cast are removed [Tomas]
v4:
  %zd is used for ssize_t [Alexander]
  %s/return -1/return -EIO [Alexander]
v5:
  Rebased.
v6:
  No change.

Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
---
 drivers/misc/mei/hdcp/mei_hdcp.c | 85 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 84 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/mei/hdcp/mei_hdcp.c b/drivers/misc/mei/hdcp/mei_hdcp.c
index 44b1aac03ff0..7d35066f21e2 100644
--- a/drivers/misc/mei/hdcp/mei_hdcp.c
+++ b/drivers/misc/mei/hdcp/mei_hdcp.c
@@ -105,10 +105,93 @@ static int mei_initiate_hdcp2_session(struct mei_cl_device *cldev,
 	return 0;
 }
 
+/*
+ * mei_verify_receiver_cert_prepare_km:
+ *	Function to verify the Receiver Certificate AKE_Send_Cert
+ *	and prepare AKE_Stored_Km or AKE_No_Stored_Km
+ *
+ * cldev		: Pointer for mei client device
+ * data			: Intel HW specific Data
+ * rx_cert		: Pointer for AKE_Send_Cert
+ * km_stored		: Pointer for pairing status flag
+ * ek_pub_km		: Pointer for output msg
+ * msg_sz		: Pointer for size of AKE_XXXXX_Km
+ *
+ * Returns 0 on Success, <0 on Failure
+ */
+static int
+mei_verify_receiver_cert_prepare_km(struct mei_cl_device *cldev,
+				    struct mei_hdcp_data *data,
+				    struct hdcp2_ake_send_cert *rx_cert,
+				    bool *km_stored,
+				    struct hdcp2_ake_no_stored_km *ek_pub_km,
+				    size_t *msg_sz)
+{
+	struct wired_cmd_verify_receiver_cert_in verify_rxcert_in = { { 0 } };
+	struct wired_cmd_verify_receiver_cert_out verify_rxcert_out = { { 0 } };
+	struct device *dev;
+	ssize_t byte;
+
+	if (!data || !rx_cert || !km_stored || !ek_pub_km || !msg_sz)
+		return -EINVAL;
+
+	dev = &cldev->dev;
+
+	verify_rxcert_in.header.api_version = HDCP_API_VERSION;
+	verify_rxcert_in.header.command_id = WIRED_VERIFY_RECEIVER_CERT;
+	verify_rxcert_in.header.status = ME_HDCP_STATUS_SUCCESS;
+	verify_rxcert_in.header.buffer_len =
+				WIRED_CMD_BUF_LEN_VERIFY_RECEIVER_CERT_IN;
+
+	verify_rxcert_in.port.integrated_port_type = data->port_type;
+	verify_rxcert_in.port.physical_port = data->port;
+
+	memcpy(&verify_rxcert_in.cert_rx, &rx_cert->cert_rx,
+	       sizeof(rx_cert->cert_rx));
+	memcpy(verify_rxcert_in.r_rx, &rx_cert->r_rx, sizeof(rx_cert->r_rx));
+	memcpy(verify_rxcert_in.rx_caps, rx_cert->rx_caps, HDCP_2_2_RXCAPS_LEN);
+
+	byte = mei_cldev_send(cldev, (u8 *)&verify_rxcert_in,
+			      sizeof(verify_rxcert_in));
+	if (byte < 0) {
+		dev_dbg(dev, "mei_cldev_send failed: %zd\n", byte);
+		return byte;
+	}
+
+	byte = mei_cldev_recv(cldev, (u8 *)&verify_rxcert_out,
+			      sizeof(verify_rxcert_out));
+	if (byte < 0) {
+		dev_dbg(dev, "mei_cldev_recv failed: %zd\n", byte);
+		return byte;
+	}
+
+	if (verify_rxcert_out.header.status != ME_HDCP_STATUS_SUCCESS) {
+		dev_dbg(dev, "ME cmd 0x%08X Failed. Status: 0x%X\n",
+			WIRED_VERIFY_RECEIVER_CERT,
+			verify_rxcert_out.header.status);
+		return -EIO;
+	}
+
+	*km_stored = verify_rxcert_out.km_stored;
+	if (verify_rxcert_out.km_stored) {
+		ek_pub_km->msg_id = HDCP_2_2_AKE_STORED_KM;
+		*msg_sz = sizeof(struct hdcp2_ake_stored_km);
+	} else {
+		ek_pub_km->msg_id = HDCP_2_2_AKE_NO_STORED_KM;
+		*msg_sz = sizeof(struct hdcp2_ake_no_stored_km);
+	}
+
+	memcpy(ek_pub_km->e_kpub_km, &verify_rxcert_out.ekm_buff,
+	       sizeof(verify_rxcert_out.ekm_buff));
+
+	return 0;
+}
+
 struct i915_hdcp_component_ops mei_hdcp_component_ops = {
 	.owner					= THIS_MODULE,
 	.initiate_hdcp2_session			= mei_initiate_hdcp2_session,
-	.verify_receiver_cert_prepare_km	= NULL,
+	.verify_receiver_cert_prepare_km	=
+					mei_verify_receiver_cert_prepare_km,
 	.verify_hprime				= NULL,
 	.store_pairing_info			= NULL,
 	.initiate_locality_check		= NULL,
-- 
2.7.4