Add validation for grpc requests and cosmos messages

hash/hash.go

@@ -93,6 +93,15 @@ func Decode(h string) (Hash, error) {
 	return Hash(hash), nil
 }
 
+// DecodeFromBytes decodes hash and checks it length.
+// It returns empty hash on nil slice of bytes.
+func DecodeFromBytes(data []byte) (Hash, error) {
+	if len(data) != size {
+		return nil, fmt.Errorf("hash: invalid length")
+	}
+	return Hash(data), nil
+}
+
 // IsZero reports whethere h represents empty hash.
 func (h Hash) IsZero() bool {
 	return len(h) == 0

protobuf/api/event.proto

@@ -27,18 +27,22 @@ message StreamEventRequest {
   message Filter {
     // hash to filter events.
     bytes hash = 1 [
+      (gogoproto.moretags) = 'validate:"omitempty,hash"',
       (gogoproto.customtype) = "github.com/mesg-foundation/engine/hash.Hash",
       (gogoproto.nullable) = false
     ];
 
     // instance's hash to filter events.
     bytes instanceHash = 2 [
+      (gogoproto.moretags) = 'validate:"omitempty,hash"',
       (gogoproto.customtype) = "github.com/mesg-foundation/engine/hash.Hash",
       (gogoproto.nullable) = false
     ];
 
     // key is the key of the event.
-    string key = 3;
+    string key = 3 [
+      (gogoproto.moretags) = 'hash:"name:3" validate:"printascii"'
+    ];
   }
 
   // Filter used to filter a stream of events.
@@ -54,7 +58,9 @@ message CreateEventRequest {
   ];
 
   // key is the key of the event.
-  string key = 2;
+  string key = 2 [
+    (gogoproto.moretags) = 'validate:"printascii"'
+  ];
 
   // data is the data for the event.
   mesg.protobuf.Struct data = 3;