api: add api definitions for the services

Add api definitions (protobuf) for services including:
 - eventlog-server
 - measurement-server
 - quote-server

Signed-off-by: Ruoyu Ying <ruoyu.ying@intel.com>

api/eventlog-server.proto

@@ -0,0 +1,27 @@
+syntax = "proto3";
+option go_package = "github.com/intel/confidential-cloud-native-primitives/service/eventlog-server/proto/getEventlog";
+
+enum CATEGORY {
+    TDX_EVENTLOG = 0;
+    TPM_EVENTLOG = 1;
+}
+
+enum LEVEL {
+    PAAS = 0;
+    SAAS = 1;
+}
+
+message GetEventlogRequest {
+    LEVEL eventlog_level = 1;
+    CATEGORY eventlog_category = 2;
+    int32 start_position = 3;
+    int32 count = 4;
+}
+
+message GetEventlogReply {
+    string eventlog_data_loc = 1;
+}
+
+service Eventlog {
+    rpc GetEventlog (GetEventlogRequest) returns (GetEventlogReply) {}
+}

api/measurement-server.proto

@@ -0,0 +1,32 @@
+syntax = "proto3";
+option go_package = "github.com/intel/confidential-cloud-native-primitives/service/measurement-server/proto/getMeasurement";
+
+package measurement;
+
+
+enum TYPE {
+    PAAS = 0;
+    SAAS = 1;
+}
+
+enum CATEGORY {
+    TEE_REPORT = 0;
+    TPM = 1;
+    TDX_RTMR = 2;
+}
+
+message GetMeasurementRequest {
+    TYPE measurement_type = 1;
+    CATEGORY measurement_category = 2;
+    string report_data = 3;
+    int32 register_index = 4;
+
+}
+
+message GetMeasurementReply {
+    string measurement = 1;
+}
+
+service Measurement {
+    rpc GetMeasurement (GetMeasurementRequest) returns (GetMeasurementReply) {}
+}

api/quote-server.proto

@@ -0,0 +1,30 @@
+syntax = "proto3";
+package quoteserver;
+
+message HealthCheckRequest {
+  string service = 1;
+}
+
+message HealthCheckResponse {
+  enum ServingStatus {
+    UNKNOWN = 0;
+    SERVING = 1;
+    NOT_SERVING = 2;
+    SERVICE_UNKNOWN = 3;
+  }
+  ServingStatus status = 1;
+}
+
+service GetQuote {
+    rpc GetQuote (GetQuoteRequest) returns (GetQuoteResponse);
+}
+
+message GetQuoteRequest {
+   string user_data = 1;
+   string nonce = 2;
+}
+
+message GetQuoteResponse {
+    string quote = 1;
+    string quote_type = 2;
+}