On 12/19/2018 8:05 PM, Daniel Vetter wrote:
On Thu, Dec 13, 2018 at 09:31:12AM +0530, Ramalingam C wrote:Implements HDCP2.2 authentication for hdcp2.2 receivers, with following steps: Authentication and Key exchange (AKE). Locality Check (LC). Session Key Exchange(SKE). DP Errata for stream type configuration for receivers.At AKE, the HDCP Receiver’s public key certificate is verified by the HDCP Transmitter. A Master Key k m is exchanged. At LC, the HDCP Transmitter enforces locality on the content by requiring that the Round Trip Time (RTT) between a pair of messages is not more than 20 ms. At SKE, The HDCP Transmitter exchanges Session Key ks with the HDCP Receiver. In DP HDCP2.2 encryption and decryption logics use the stream type as one of the parameter. So Before enabling the Encryption DP HDCP2.2 receiver needs to be communicated with stream type. This is added to spec as ERRATA. This generic implementation is complete only with the hdcp2 specific functions defined at hdcp_shim. v2: Rebased. v3: %s/PARING/PAIRING Coding style fixing [Uma] v4: Rebased as part of patch reordering. Defined the functions for mei services. [Daniel] v5: Redefined the mei service functions as per comp redesign. Required intel_hdcp members are defined [Sean Paul] v6: Typo of cipher is Fixed [Uma] %s/uintxx_t/uxx Check for comp_master is removed. v7: Adjust to the new interface. Avoid using bool structure members. [Tomas] v8: Rebased. Signed-off-by: Ramalingam C <ramalinga...@intel.com> --- drivers/gpu/drm/i915/intel_drv.h | 34 ++++++ drivers/gpu/drm/i915/intel_hdcp.c | 211 +++++++++++++++++++++++++++++++++++--- 2 files changed, 230 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index 6d5361616ca3..a6b632d71490 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -387,6 +387,22 @@ struct intel_hdcp_shim { /* Detects whether Panel is HDCP2.2 capable */ int (*hdcp_2_2_capable)(struct intel_digital_port *intel_dig_port, bool *capable); + + /* Write HDCP2.2 messages */ + int (*write_2_2_msg)(struct intel_digital_port *intel_dig_port, + void *buf, size_t size); + + /* Read HDCP2.2 messages */ + int (*read_2_2_msg)(struct intel_digital_port *intel_dig_port, + u8 msg_id, void *buf, size_t size); + + /* + * Implementation of DP HDCP2.2 Errata for the communication of stream + * type to Receivers. In DP HDCP2.2 Stream type is one of the input to + * the HDCP2.2 Cipher for En/De-Cryption. Not applicable for HDMI. + */ + int (*config_stream_type)(struct intel_digital_port *intel_dig_port, + void *buf, size_t size); };struct intel_hdcp {@@ -414,6 +430,24 @@ struct intel_hdcp { */ u8 content_type; struct hdcp_port_data port_data; + + u8 is_paired; + u8 is_repeater;Make these two bool, will simplify the code a bunch.
Seems there is a movement for not to use the bool in structures. Thats why I have changed these from bool to u8 from v8 onwards. Checkpatch also complains on this
+ + /* + * Count of ReceiverID_List received. Initialized to 0 at AKE_INIT. + * Incremented after processing the RepeaterAuth_Send_ReceiverID_List. + * When it rolls over re-auth has to be triggered. + */ + u32 seq_num_v; + + /* + * Count of RepeaterAuth_Stream_Manage msg propagated. + * Initialized to 0 on AKE_INIT. Incremented after every successful + * transmission of RepeaterAuth_Stream_Manage message. When it rolls + * over re-Auth has to be triggered. + */ + u32 seq_num_m; };struct intel_connector {diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c index f0ee448e6546..f1f0ef294e20 100644 --- a/drivers/gpu/drm/i915/intel_hdcp.c +++ b/drivers/gpu/drm/i915/intel_hdcp.c @@ -18,6 +18,7 @@#define KEY_LOAD_TRIES 5#define ENCRYPT_STATUS_CHANGE_TIMEOUT_MS 50 +#define HDCP2_LC_RETRY_CNT 3staticbool intel_hdcp_is_ksv_valid(u8 *ksv) @@ -854,7 +855,7 @@ bool is_hdcp_supported(struct drm_i915_private *dev_priv, enum port port) return INTEL_GEN(dev_priv) >= 9 && port < PORT_E; }-static __attribute__((unused)) int+static int hdcp2_prepare_ake_init(struct intel_connector *connector, struct hdcp2_ake_init *ake_data) { @@ -875,7 +876,7 @@ hdcp2_prepare_ake_init(struct intel_connector *connector, return ret; }-static __attribute__((unused)) int+static int hdcp2_verify_rx_cert_prepare_km(struct intel_connector *connector, struct hdcp2_ake_send_cert *rx_cert, bool *paired, @@ -897,9 +898,8 @@ hdcp2_verify_rx_cert_prepare_km(struct intel_connector *connector, return ret; }-static __attribute__((unused)) int-hdcp2_verify_hprime(struct intel_connector *connector, - struct hdcp2_ake_send_hprime *rx_hprime) +static int hdcp2_verify_hprime(struct intel_connector *connector, + struct hdcp2_ake_send_hprime *rx_hprime) { struct hdcp_port_data *data = &connector->hdcp.port_data; struct drm_i915_private *dev_priv = to_i915(connector->base.dev); @@ -913,7 +913,7 @@ hdcp2_verify_hprime(struct intel_connector *connector, return ret; }-static __attribute__((unused)) int+static int hdcp2_store_pairing_info(struct intel_connector *connector, struct hdcp2_ake_send_pairing_info *pairing_info) { @@ -930,7 +930,7 @@ hdcp2_store_pairing_info(struct intel_connector *connector, return ret; }-static __attribute__((unused)) int+static int hdcp2_prepare_lc_init(struct intel_connector *connector, struct hdcp2_lc_init *lc_init) { @@ -947,7 +947,7 @@ hdcp2_prepare_lc_init(struct intel_connector *connector, return ret; }-static __attribute__((unused)) int+static int hdcp2_verify_lprime(struct intel_connector *connector, struct hdcp2_lc_send_lprime *rx_lprime) { @@ -963,9 +963,8 @@ hdcp2_verify_lprime(struct intel_connector *connector, return ret; }-static __attribute__((unused))-int hdcp2_prepare_skey(struct intel_connector *connector, - struct hdcp2_ske_send_eks *ske_data) +static int hdcp2_prepare_skey(struct intel_connector *connector, + struct hdcp2_ske_send_eks *ske_data) { struct hdcp_port_data *data = &connector->hdcp.port_data; struct drm_i915_private *dev_priv = to_i915(connector->base.dev); @@ -1016,8 +1015,7 @@ hdcp2_verify_mprime(struct intel_connector *connector, return ret; }-static __attribute__((unused))-int hdcp2_authenticate_port(struct intel_connector *connector) +static int hdcp2_authenticate_port(struct intel_connector *connector) { struct hdcp_port_data *data = &connector->hdcp.port_data; struct drm_i915_private *dev_priv = to_i915(connector->base.dev); @@ -1045,11 +1043,194 @@ static int hdcp2_deauthenticate_port(struct intel_connector *connector) return hdcp2_close_mei_session(connector); }+/* Authentication flow starts from here */+static int hdcp2_authentication_key_exchange(struct intel_connector *connector) +{ + struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector); + struct intel_hdcp *hdcp = &connector->hdcp; + union { + struct hdcp2_ake_init ake_init; + struct hdcp2_ake_send_cert send_cert; + struct hdcp2_ake_no_stored_km no_stored_km; + struct hdcp2_ake_send_hprime send_hprime; + struct hdcp2_ake_send_pairing_info pairing_info; + } msgs; + const struct intel_hdcp_shim *shim = hdcp->shim; + size_t size; + int ret; + bool is_paired; + + /* Init for seq_num */ + hdcp->seq_num_v = 0; + hdcp->seq_num_m = 0; + + ret = hdcp2_prepare_ake_init(connector, &msgs.ake_init); + if (ret < 0) + return ret; + + ret = shim->write_2_2_msg(intel_dig_port, &msgs.ake_init, + sizeof(msgs.ake_init)); + if (ret < 0) + return ret; + + ret = shim->read_2_2_msg(intel_dig_port, HDCP_2_2_AKE_SEND_CERT, + &msgs.send_cert, sizeof(msgs.send_cert)); + if (ret < 0) + return ret;sink should give us the initial key with 100ms. I guess there's going to be a patch later on to check that?
Timings are checked at read_2_2_msg as per the msg_id
+ + if (msgs.send_cert.rx_caps[0] != HDCP_2_2_RX_CAPS_VERSION_VAL) + return -EINVAL; + + hdcp->is_repeater = HDCP_2_2_RX_REPEATER(msgs.send_cert.rx_caps[2]) ? + 1 : 0;If you make is_repeater of type bool you can simplify this.
Yes. But it is advised to not to use bool in struct
+ + /* + * Here msgs.no_stored_km will hold msgs corresponding to the km + * stored also. + */ + ret = hdcp2_verify_rx_cert_prepare_km(connector, &msgs.send_cert, + &is_paired, + &msgs.no_stored_km, &size); + if (ret < 0) + return ret; + + hdcp->is_paired = is_paired ? 1 : 0;The ? 1 : 0 is redundant if you make is_paired type bool.+ + ret = shim->write_2_2_msg(intel_dig_port, &msgs.no_stored_km, size); + if (ret < 0) + return ret; + + ret = shim->read_2_2_msg(intel_dig_port, HDCP_2_2_AKE_SEND_HPRIME, + &msgs.send_hprime, sizeof(msgs.send_hprime)); + if (ret < 0) + return ret; + + ret = hdcp2_verify_hprime(connector, &msgs.send_hprime); + if (ret < 0) + return ret; + + if (!hdcp->is_paired) { + /* Pairing is required */ + ret = shim->read_2_2_msg(intel_dig_port, + HDCP_2_2_AKE_SEND_PAIRING_INFO, + &msgs.pairing_info, + sizeof(msgs.pairing_info)); + if (ret < 0) + return ret; + + ret = hdcp2_store_pairing_info(connector, &msgs.pairing_info); + if (ret < 0) + return ret; + hdcp->is_paired = 1;s/1/true/+ } + + return 0; +} + +static int hdcp2_locality_check(struct intel_connector *connector) +{ + struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector); + struct intel_hdcp *hdcp = &connector->hdcp; + union { + struct hdcp2_lc_init lc_init; + struct hdcp2_lc_send_lprime send_lprime; + } msgs; + const struct intel_hdcp_shim *shim = hdcp->shim; + int tries = HDCP2_LC_RETRY_CNT, ret, i; + + for (i = 0; i < tries; i++) { + ret = hdcp2_prepare_lc_init(connector, &msgs.lc_init); + if (ret < 0) + continue; + + ret = shim->write_2_2_msg(intel_dig_port, &msgs.lc_init, + sizeof(msgs.lc_init)); + if (ret < 0) + continue; + + ret = shim->read_2_2_msg(intel_dig_port, + HDCP_2_2_LC_SEND_LPRIME, + &msgs.send_lprime, + sizeof(msgs.send_lprime)); + if (ret < 0) + continue; + + ret = hdcp2_verify_lprime(connector, &msgs.send_lprime); + if (!ret) + break;We're not checking that the sink replies quickly enough here. Sink needs to reply in 20ms. Can be a followup I guess. Also just noticed that we seem to lack all these timing checks for hdcp1 too, at least we don't fail auth if the sink takes too long.
Shim takes care of it. It we dont compliance will fail.
+ } + + return ret; +} + +static int hdcp2_session_key_exchange(struct intel_connector *connector) +{ + struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector); + struct intel_hdcp *hdcp = &connector->hdcp; + struct hdcp2_ske_send_eks send_eks; + int ret; + + ret = hdcp2_prepare_skey(connector, &send_eks); + if (ret < 0) + return ret; + + ret = hdcp->shim->write_2_2_msg(intel_dig_port, &send_eks, + sizeof(send_eks)); + if (ret < 0) + return ret; + + return 0; +} + static int hdcp2_authenticate_sink(struct intel_connector *connector) { - DRM_ERROR("Sink authentication is done in subsequent patches\n"); + struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector); + struct intel_hdcp *hdcp = &connector->hdcp; + const struct intel_hdcp_shim *shim = hdcp->shim; + struct hdcp2_dp_errata_stream_type stream_type_msg; + int ret;- return -EINVAL;+ ret = hdcp2_authentication_key_exchange(connector); + if (ret < 0) { + DRM_DEBUG_KMS("AKE Failed. Err : %d\n", ret); + return ret; + } + + ret = hdcp2_locality_check(connector); + if (ret < 0) { + DRM_DEBUG_KMS("Locality Check failed. Err : %d\n", ret); + return ret; + } + + ret = hdcp2_session_key_exchange(connector); + if (ret < 0) { + DRM_DEBUG_KMS("SKE Failed. Err : %d\n", ret); + return ret; + } + + if (!hdcp->is_repeater && shim->config_stream_type) { + /* + * Errata for DP: As Stream type is used for encryption, + * Receiver should be communicated with stream type for the + * decryption of the content. + * Repeater will be communicated with stream type as a + * part of it's auth later in time. + */I'm not following what you want to say with this comment, and haven't found anything in the hdcp2 dp spec about this either.
this is there in the errata of DP HDCP2.2 spec. hdcp2.2 encryption algo involves the stream type as a parameter. And as part of hdcp auth mentioned in base spec DP repeaters receive that details to decrypt the content. But DP receivers dont get it. So errata adds the missing piece for decryption. -Ram
+ stream_type_msg.msg_id = HDCP_2_2_ERRATA_DP_STREAM_TYP:E; + stream_type_msg.stream_type = hdcp->content_type; + + ret = shim->config_stream_type(intel_dig_port, &stream_type_msg, + sizeof(stream_type_msg)); + if (ret < 0) + return ret; + } + + hdcp->port_data.streams[0].stream_type = hdcp->content_type; + ret = hdcp2_authenticate_port(connector); + if (ret < 0) + return ret; + + return ret; }With thy types changed to bool and the dp errata cleared up somehow: Reviewed-by: Daniel Vetter <daniel.vet...@ffwll.ch>static int hdcp2_enable_encryption(struct intel_connector *connector)-- 2.7.4
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