NOISSUE - Add IsChannelOwner grpc endpoint (#1366)

* Add CanAccessChannelByOwner grpc endpoint

Signed-off-by: Darko Draskovic <darko.draskovic@gmail.com>

* Rename grpc endpoint to IsChannelOwner

Signed-off-by: Darko Draskovic <darko.draskovic@gmail.com>

* Add tests for IsChannelOwner grpc

Signed-off-by: Darko Draskovic <darko.draskovic@gmail.com>

* Bump protoc version

Signed-off-by: Darko Draskovic <darko.draskovic@gmail.com>

* Make proto

Signed-off-by: Darko Draskovic <darko.draskovic@gmail.com>

auth.pb.go

@@ -82,6 +82,61 @@ func (m *AccessByKeyReq) GetChanID() string {
 	return ""
 }
 
+type ChannelOwnerReq struct {
+	Owner                string   `protobuf:"bytes,1,opt,name=owner,proto3" json:"owner,omitempty"`
+	ChanID               string   `protobuf:"bytes,2,opt,name=chanID,proto3" json:"chanID,omitempty"`
+	XXX_NoUnkeyedLiteral struct{} `json:"-"`
+	XXX_unrecognized     []byte   `json:"-"`
+	XXX_sizecache        int32    `json:"-"`
+}
+
+func (m *ChannelOwnerReq) Reset()         { *m = ChannelOwnerReq{} }
+func (m *ChannelOwnerReq) String() string { return proto.CompactTextString(m) }
+func (*ChannelOwnerReq) ProtoMessage()    {}
+func (*ChannelOwnerReq) Descriptor() ([]byte, []int) {
+	return fileDescriptor_8bbd6f3875b0e874, []int{1}
+}
+func (m *ChannelOwnerReq) XXX_Unmarshal(b []byte) error {
+	return m.Unmarshal(b)
+}
+func (m *ChannelOwnerReq) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	if deterministic {
+		return xxx_messageInfo_ChannelOwnerReq.Marshal(b, m, deterministic)
+	} else {
+		b = b[:cap(b)]
+		n, err := m.MarshalToSizedBuffer(b)
+		if err != nil {
+			return nil, err
+		}
+		return b[:n], nil
+	}
+}
+func (m *ChannelOwnerReq) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_ChannelOwnerReq.Merge(m, src)
+}
+func (m *ChannelOwnerReq) XXX_Size() int {
+	return m.Size()
+}
+func (m *ChannelOwnerReq) XXX_DiscardUnknown() {
+	xxx_messageInfo_ChannelOwnerReq.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_ChannelOwnerReq proto.InternalMessageInfo
+
+func (m *ChannelOwnerReq) GetOwner() string {
+	if m != nil {
+		return m.Owner
+	}
+	return ""
+}
+
+func (m *ChannelOwnerReq) GetChanID() string {
+	if m != nil {
+		return m.ChanID
+	}
+	return ""
+}
+
 type ThingID struct {
 	Value                string   `protobuf:"bytes,1,opt,name=value,proto3" json:"value,omitempty"`
 	XXX_NoUnkeyedLiteral struct{} `json:"-"`
@@ -93,7 +148,7 @@ func (m *ThingID) Reset()         { *m = ThingID{} }
 func (m *ThingID) String() string { return proto.CompactTextString(m) }
 func (*ThingID) ProtoMessage()    {}
 func (*ThingID) Descriptor() ([]byte, []int) {
-	return fileDescriptor_8bbd6f3875b0e874, []int{1}
+	return fileDescriptor_8bbd6f3875b0e874, []int{2}
 }
 func (m *ThingID) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -129,6 +184,53 @@ func (m *ThingID) GetValue() string {
 	return ""
 }
 
+type ChannelID struct {
+	Value                string   `protobuf:"bytes,1,opt,name=value,proto3" json:"value,omitempty"`
+	XXX_NoUnkeyedLiteral struct{} `json:"-"`
+	XXX_unrecognized     []byte   `json:"-"`
+	XXX_sizecache        int32    `json:"-"`
+}
+
+func (m *ChannelID) Reset()         { *m = ChannelID{} }
+func (m *ChannelID) String() string { return proto.CompactTextString(m) }
+func (*ChannelID) ProtoMessage()    {}
+func (*ChannelID) Descriptor() ([]byte, []int) {
+	return fileDescriptor_8bbd6f3875b0e874, []int{3}
+}
+func (m *ChannelID) XXX_Unmarshal(b []byte) error {
+	return m.Unmarshal(b)
+}
+func (m *ChannelID) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	if deterministic {
+		return xxx_messageInfo_ChannelID.Marshal(b, m, deterministic)
+	} else {
+		b = b[:cap(b)]
+		n, err := m.MarshalToSizedBuffer(b)
+		if err != nil {
+			return nil, err
+		}
+		return b[:n], nil
+	}
+}
+func (m *ChannelID) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_ChannelID.Merge(m, src)
+}
+func (m *ChannelID) XXX_Size() int {
+	return m.Size()
+}
+func (m *ChannelID) XXX_DiscardUnknown() {
+	xxx_messageInfo_ChannelID.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_ChannelID proto.InternalMessageInfo
+
+func (m *ChannelID) GetValue() string {
+	if m != nil {
+		return m.Value
+	}
+	return ""
+}
+
 type AccessByIDReq struct {
 	ThingID              string   `protobuf:"bytes,1,opt,name=thingID,proto3" json:"thingID,omitempty"`
 	ChanID               string   `protobuf:"bytes,2,opt,name=chanID,proto3" json:"chanID,omitempty"`
@@ -141,7 +243,7 @@ func (m *AccessByIDReq) Reset()         { *m = AccessByIDReq{} }
 func (m *AccessByIDReq) String() string { return proto.CompactTextString(m) }
 func (*AccessByIDReq) ProtoMessage()    {}
 func (*AccessByIDReq) Descriptor() ([]byte, []int) {
-	return fileDescriptor_8bbd6f3875b0e874, []int{2}
+	return fileDescriptor_8bbd6f3875b0e874, []int{4}
 }
 func (m *AccessByIDReq) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -198,7 +300,7 @@ func (m *Token) Reset()         { *m = Token{} }
 func (m *Token) String() string { return proto.CompactTextString(m) }
 func (*Token) ProtoMessage()    {}
 func (*Token) Descriptor() ([]byte, []int) {
-	return fileDescriptor_8bbd6f3875b0e874, []int{3}
+	return fileDescriptor_8bbd6f3875b0e874, []int{5}
 }
 func (m *Token) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -246,7 +348,7 @@ func (m *UserIdentity) Reset()         { *m = UserIdentity{} }
 func (m *UserIdentity) String() string { return proto.CompactTextString(m) }
 func (*UserIdentity) ProtoMessage()    {}
 func (*UserIdentity) Descriptor() ([]byte, []int) {
-	return fileDescriptor_8bbd6f3875b0e874, []int{4}
+	return fileDescriptor_8bbd6f3875b0e874, []int{6}
 }
 func (m *UserIdentity) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -302,7 +404,7 @@ func (m *IssueReq) Reset()         { *m = IssueReq{} }
 func (m *IssueReq) String() string { return proto.CompactTextString(m) }
 func (*IssueReq) ProtoMessage()    {}
 func (*IssueReq) Descriptor() ([]byte, []int) {
-	return fileDescriptor_8bbd6f3875b0e874, []int{5}
+	return fileDescriptor_8bbd6f3875b0e874, []int{7}
 }
 func (m *IssueReq) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -365,7 +467,7 @@ func (m *AuthorizeReq) Reset()         { *m = AuthorizeReq{} }
 func (m *AuthorizeReq) String() string { return proto.CompactTextString(m) }
 func (*AuthorizeReq) ProtoMessage()    {}
 func (*AuthorizeReq) Descriptor() ([]byte, []int) {
-	return fileDescriptor_8bbd6f3875b0e874, []int{6}
+	return fileDescriptor_8bbd6f3875b0e874, []int{8}
 }
 func (m *AuthorizeReq) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -426,7 +528,7 @@ func (m *AuthorizeRes) Reset()         { *m = AuthorizeRes{} }
 func (m *AuthorizeRes) String() string { return proto.CompactTextString(m) }
 func (*AuthorizeRes) ProtoMessage()    {}
 func (*AuthorizeRes) Descriptor() ([]byte, []int) {
-	return fileDescriptor_8bbd6f3875b0e874, []int{7}
+	return fileDescriptor_8bbd6f3875b0e874, []int{9}
 }
 func (m *AuthorizeRes) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -475,7 +577,7 @@ func (m *Assignment) Reset()         { *m = Assignment{} }
 func (m *Assignment) String() string { return proto.CompactTextString(m) }
 func (*Assignment) ProtoMessage()    {}
 func (*Assignment) Descriptor() ([]byte, []int) {
-	return fileDescriptor_8bbd6f3875b0e874, []int{8}
+	return fileDescriptor_8bbd6f3875b0e874, []int{10}
 }
 func (m *Assignment) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -540,7 +642,7 @@ func (m *MembersReq) Reset()         { *m = MembersReq{} }
 func (m *MembersReq) String() string { return proto.CompactTextString(m) }
 func (*MembersReq) ProtoMessage()    {}
 func (*MembersReq) Descriptor() ([]byte, []int) {
-	return fileDescriptor_8bbd6f3875b0e874, []int{9}
+	return fileDescriptor_8bbd6f3875b0e874, []int{11}
 }
 func (m *MembersReq) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -619,7 +721,7 @@ func (m *MembersRes) Reset()         { *m = MembersRes{} }
 func (m *MembersRes) String() string { return proto.CompactTextString(m) }
 func (*MembersRes) ProtoMessage()    {}
 func (*MembersRes) Descriptor() ([]byte, []int) {
-	return fileDescriptor_8bbd6f3875b0e874, []int{10}
+	return fileDescriptor_8bbd6f3875b0e874, []int{12}
 }
 func (m *MembersRes) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -685,7 +787,9 @@ func (m *MembersRes) GetMembers() []string {
 
 func init() {
 	proto.RegisterType((*AccessByKeyReq)(nil), "mainflux.AccessByKeyReq")
+	proto.RegisterType((*ChannelOwnerReq)(nil), "mainflux.ChannelOwnerReq")
 	proto.RegisterType((*ThingID)(nil), "mainflux.ThingID")
+	proto.RegisterType((*ChannelID)(nil), "mainflux.ChannelID")
 	proto.RegisterType((*AccessByIDReq)(nil), "mainflux.AccessByIDReq")
 	proto.RegisterType((*Token)(nil), "mainflux.Token")
 	proto.RegisterType((*UserIdentity)(nil), "mainflux.UserIdentity")
@@ -700,44 +804,47 @@ func init() {
 func init() { proto.RegisterFile("auth.proto", fileDescriptor_8bbd6f3875b0e874) }
 
 var fileDescriptor_8bbd6f3875b0e874 = []byte{
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+	0x28, 0x78, 0xf8, 0xb5, 0x09, 0x43, 0x71, 0xf2, 0xf4, 0x35, 0x49, 0x2f, 0x82, 0x39, 0x41, 0x47,
+	0x30, 0x3a, 0xf1, 0x63, 0xcd, 0x87, 0xc8, 0xb4, 0x0b, 0xfb, 0xda, 0x57, 0xed, 0x69, 0xfd, 0x5f,
+	0xfe, 0xa2, 0x7c, 0x83, 0x0d, 0x74, 0x0a, 0x23, 0x97, 0xea, 0x3e, 0x44, 0xb7, 0xcb, 0xb2, 0x6b,
+	0xfe, 0xb4, 0xc6, 0xb6, 0xfc, 0x20, 0xd8, 0xc5, 0x07, 0xc1, 0x3e, 0xe5, 0x1f, 0x04, 0x6c, 0xa0,
+	0x63, 0x18, 0x6a, 0x7d, 0xb8, 0x0e, 0xba, 0xf5, 0x77, 0x1b, 0xc2, 0x60, 0x37, 0x70, 0x3c, 0x80,
+	0xbe, 0x74, 0xc9, 0x22, 0x47, 0xdb, 0x5a, 0xaf, 0xfc, 0x6f, 0xad, 0x6c, 0xfe, 0xf0, 0x7b, 0x13,
+	0xfe, 0xe3, 0xa7, 0x59, 0x6c, 0xc3, 0x86, 0x8e, 0x70, 0x0d, 0x42, 0x65, 0x75, 0x61, 0x23, 0xeb,
+	0x3a, 0x25, 0x36, 0xd0, 0xe3, 0x9b, 0x14, 0xc7, 0x65, 0x42, 0x37, 0x30, 0x36, 0xd0, 0x33, 0x18,
+	0x6c, 0x0c, 0x81, 0xb4, 0x32, 0xdd, 0x6b, 0x56, 0x75, 0x9e, 0x62, 0x03, 0x3d, 0x85, 0xae, 0xf4,
+	0x07, 0xda, 0xd5, 0x6a, 0x36, 0x8e, 0xb9, 0x61, 0x43, 0x4f, 0xa0, 0xa7, 0xee, 0x4f, 0x7f, 0x5a,
+	0x5a, 0xc2, 0xaa, 0xca, 0x52, 0x6c, 0x1c, 0xef, 0xfc, 0xb8, 0x9c, 0x34, 0x7e, 0x5e, 0x4e, 0x1a,
+	0xbf, 0x2e, 0x27, 0x8d, 0x6f, 0xbf, 0x27, 0xc6, 0xac, 0x2b, 0xc8, 0x1f, 0xfe, 0x09, 0x00, 0x00,
+	0xff, 0xff, 0x14, 0xf9, 0x10, 0x64, 0xf9, 0x05, 0x00, 0x00,
 }
 
 // Reference imports to suppress errors if they are not otherwise used.
@@ -753,6 +860,7 @@ const _ = grpc.SupportPackageIsVersion4
 // For semantics around ctx use and closing/ending streaming RPCs, please refer to https://godoc.org/google.golang.org/grpc#ClientConn.NewStream.
 type ThingsServiceClient interface {
 	CanAccessByKey(ctx context.Context, in *AccessByKeyReq, opts ...grpc.CallOption) (*ThingID, error)
+	IsChannelOwner(ctx context.Context, in *ChannelOwnerReq, opts ...grpc.CallOption) (*empty.Empty, error)
 	CanAccessByID(ctx context.Context, in *AccessByIDReq, opts ...grpc.CallOption) (*empty.Empty, error)
 	Identify(ctx context.Context, in *Token, opts ...grpc.CallOption) (*ThingID, error)
 }
@@ -774,6 +882,15 @@ func (c *thingsServiceClient) CanAccessByKey(ctx context.Context, in *AccessByKe
 	return out, nil
 }
 
+func (c *thingsServiceClient) IsChannelOwner(ctx context.Context, in *ChannelOwnerReq, opts ...grpc.CallOption) (*empty.Empty, error) {
+	out := new(empty.Empty)
+	err := c.cc.Invoke(ctx, "/mainflux.ThingsService/IsChannelOwner", in, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
 func (c *thingsServiceClient) CanAccessByID(ctx context.Context, in *AccessByIDReq, opts ...grpc.CallOption) (*empty.Empty, error) {
 	out := new(empty.Empty)
 	err := c.cc.Invoke(ctx, "/mainflux.ThingsService/CanAccessByID", in, out, opts...)
@@ -795,6 +912,7 @@ func (c *thingsServiceClient) Identify(ctx context.Context, in *Token, opts ...g
 // ThingsServiceServer is the server API for ThingsService service.
 type ThingsServiceServer interface {
 	CanAccessByKey(context.Context, *AccessByKeyReq) (*ThingID, error)
+	IsChannelOwner(context.Context, *ChannelOwnerReq) (*empty.Empty, error)
 	CanAccessByID(context.Context, *AccessByIDReq) (*empty.Empty, error)
 	Identify(context.Context, *Token) (*ThingID, error)
 }
@@ -806,6 +924,9 @@ type UnimplementedThingsServiceServer struct {
 func (*UnimplementedThingsServiceServer) CanAccessByKey(ctx context.Context, req *AccessByKeyReq) (*ThingID, error) {
 	return nil, status.Errorf(codes.Unimplemented, "method CanAccessByKey not implemented")
 }
+func (*UnimplementedThingsServiceServer) IsChannelOwner(ctx context.Context, req *ChannelOwnerReq) (*empty.Empty, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method IsChannelOwner not implemented")
+}
 func (*UnimplementedThingsServiceServer) CanAccessByID(ctx context.Context, req *AccessByIDReq) (*empty.Empty, error) {
 	return nil, status.Errorf(codes.Unimplemented, "method CanAccessByID not implemented")
 }
@@ -835,6 +956,24 @@ func _ThingsService_CanAccessByKey_Handler(srv interface{}, ctx context.Context,
 	return interceptor(ctx, in, info, handler)
 }
 
+func _ThingsService_IsChannelOwner_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(ChannelOwnerReq)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(ThingsServiceServer).IsChannelOwner(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/mainflux.ThingsService/IsChannelOwner",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(ThingsServiceServer).IsChannelOwner(ctx, req.(*ChannelOwnerReq))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
 func _ThingsService_CanAccessByID_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
 	in := new(AccessByIDReq)
 	if err := dec(in); err != nil {
@@ -879,6 +1018,10 @@ var _ThingsService_serviceDesc = grpc.ServiceDesc{
 			MethodName: "CanAccessByKey",
 			Handler:    _ThingsService_CanAccessByKey_Handler,
 		},
+		{
+			MethodName: "IsChannelOwner",
+			Handler:    _ThingsService_IsChannelOwner_Handler,
+		},
 		{
 			MethodName: "CanAccessByID",
 			Handler:    _ThingsService_CanAccessByID_Handler,
@@ -1149,6 +1292,47 @@ func (m *AccessByKeyReq) MarshalToSizedBuffer(dAtA []byte) (int, error) {
 	return len(dAtA) - i, nil
 }
 
+func (m *ChannelOwnerReq) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalToSizedBuffer(dAtA[:size])
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *ChannelOwnerReq) MarshalTo(dAtA []byte) (int, error) {
+	size := m.Size()
+	return m.MarshalToSizedBuffer(dAtA[:size])
+}
+
+func (m *ChannelOwnerReq) MarshalToSizedBuffer(dAtA []byte) (int, error) {
+	i := len(dAtA)
+	_ = i
+	var l int
+	_ = l
+	if m.XXX_unrecognized != nil {
+		i -= len(m.XXX_unrecognized)
+		copy(dAtA[i:], m.XXX_unrecognized)
+	}
+	if len(m.ChanID) > 0 {
+		i -= len(m.ChanID)
+		copy(dAtA[i:], m.ChanID)
+		i = encodeVarintAuth(dAtA, i, uint64(len(m.ChanID)))
+		i--
+		dAtA[i] = 0x12
+	}
+	if len(m.Owner) > 0 {
+		i -= len(m.Owner)
+		copy(dAtA[i:], m.Owner)
+		i = encodeVarintAuth(dAtA, i, uint64(len(m.Owner)))
+		i--
+		dAtA[i] = 0xa
+	}
+	return len(dAtA) - i, nil
+}
+
 func (m *ThingID) Marshal() (dAtA []byte, err error) {
 	size := m.Size()
 	dAtA = make([]byte, size)
@@ -1183,6 +1367,40 @@ func (m *ThingID) MarshalToSizedBuffer(dAtA []byte) (int, error) {
 	return len(dAtA) - i, nil
 }
 
+func (m *ChannelID) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalToSizedBuffer(dAtA[:size])
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *ChannelID) MarshalTo(dAtA []byte) (int, error) {
+	size := m.Size()
+	return m.MarshalToSizedBuffer(dAtA[:size])
+}
+
+func (m *ChannelID) MarshalToSizedBuffer(dAtA []byte) (int, error) {
+	i := len(dAtA)
+	_ = i
+	var l int
+	_ = l
+	if m.XXX_unrecognized != nil {
+		i -= len(m.XXX_unrecognized)
+		copy(dAtA[i:], m.XXX_unrecognized)
+	}
+	if len(m.Value) > 0 {
+		i -= len(m.Value)
+		copy(dAtA[i:], m.Value)
+		i = encodeVarintAuth(dAtA, i, uint64(len(m.Value)))
+		i--
+		dAtA[i] = 0xa
+	}
+	return len(dAtA) - i, nil
+}
+
 func (m *AccessByIDReq) Marshal() (dAtA []byte, err error) {
 	size := m.Size()
 	dAtA = make([]byte, size)
@@ -1625,6 +1843,26 @@ func (m *AccessByKeyReq) Size() (n int) {
 	return n
 }
 
+func (m *ChannelOwnerReq) Size() (n int) {
+	if m == nil {
+		return 0
+	}
+	var l int
+	_ = l
+	l = len(m.Owner)
+	if l > 0 {
+		n += 1 + l + sovAuth(uint64(l))
+	}
+	l = len(m.ChanID)
+	if l > 0 {
+		n += 1 + l + sovAuth(uint64(l))
+	}
+	if m.XXX_unrecognized != nil {
+		n += len(m.XXX_unrecognized)
+	}
+	return n
+}
+
 func (m *ThingID) Size() (n int) {
 	if m == nil {
 		return 0
@@ -1641,6 +1879,22 @@ func (m *ThingID) Size() (n int) {
 	return n
 }
 
+func (m *ChannelID) Size() (n int) {
+	if m == nil {
+		return 0
+	}
+	var l int
+	_ = l
+	l = len(m.Value)
+	if l > 0 {
+		n += 1 + l + sovAuth(uint64(l))
+	}
+	if m.XXX_unrecognized != nil {
+		n += len(m.XXX_unrecognized)
+	}
+	return n
+}
+
 func (m *AccessByIDReq) Size() (n int) {
 	if m == nil {
 		return 0
@@ -1968,6 +2222,124 @@ func (m *AccessByKeyReq) Unmarshal(dAtA []byte) error {
 	}
 	return nil
 }
+func (m *ChannelOwnerReq) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowAuth
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= uint64(b&0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: ChannelOwnerReq: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: ChannelOwnerReq: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Owner", wireType)
+			}
+			var stringLen uint64
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowAuth
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				stringLen |= uint64(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			intStringLen := int(stringLen)
+			if intStringLen < 0 {
+				return ErrInvalidLengthAuth
+			}
+			postIndex := iNdEx + intStringLen
+			if postIndex < 0 {
+				return ErrInvalidLengthAuth
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Owner = string(dAtA[iNdEx:postIndex])
+			iNdEx = postIndex
+		case 2:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field ChanID", wireType)
+			}
+			var stringLen uint64
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowAuth
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				stringLen |= uint64(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			intStringLen := int(stringLen)
+			if intStringLen < 0 {
+				return ErrInvalidLengthAuth
+			}
+			postIndex := iNdEx + intStringLen
+			if postIndex < 0 {
+				return ErrInvalidLengthAuth
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.ChanID = string(dAtA[iNdEx:postIndex])
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipAuth(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthAuth
+			}
+			if (iNdEx + skippy) < 0 {
+				return ErrInvalidLengthAuth
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.XXX_unrecognized = append(m.XXX_unrecognized, dAtA[iNdEx:iNdEx+skippy]...)
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
 func (m *ThingID) Unmarshal(dAtA []byte) error {
 	l := len(dAtA)
 	iNdEx := 0
@@ -2054,6 +2426,92 @@ func (m *ThingID) Unmarshal(dAtA []byte) error {
 	}
 	return nil
 }
+func (m *ChannelID) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowAuth
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= uint64(b&0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: ChannelID: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: ChannelID: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Value", wireType)
+			}
+			var stringLen uint64
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowAuth
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				stringLen |= uint64(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			intStringLen := int(stringLen)
+			if intStringLen < 0 {
+				return ErrInvalidLengthAuth
+			}
+			postIndex := iNdEx + intStringLen
+			if postIndex < 0 {
+				return ErrInvalidLengthAuth
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Value = string(dAtA[iNdEx:postIndex])
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipAuth(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthAuth
+			}
+			if (iNdEx + skippy) < 0 {
+				return ErrInvalidLengthAuth
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.XXX_unrecognized = append(m.XXX_unrecognized, dAtA[iNdEx:iNdEx+skippy]...)
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
 func (m *AccessByIDReq) Unmarshal(dAtA []byte) error {
 	l := len(dAtA)
 	iNdEx := 0

auth.proto

@@ -9,6 +9,7 @@ import "google/protobuf/empty.proto";
 
 service ThingsService {
     rpc CanAccessByKey(AccessByKeyReq) returns (ThingID) {}
+    rpc IsChannelOwner(ChannelOwnerReq) returns (google.protobuf.Empty) {}
     rpc CanAccessByID(AccessByIDReq) returns (google.protobuf.Empty) {}
     rpc Identify(Token) returns (ThingID) {}
 }
@@ -26,10 +27,19 @@ message AccessByKeyReq {
     string chanID = 2;
 }
 
+message ChannelOwnerReq {
+    string owner  = 1;
+    string chanID = 2;
+}
+
 message ThingID {
     string value = 1;
 }
 
+message ChannelID {
+    string value = 1;
+}
+
 message AccessByIDReq {
     string thingID = 1;
     string chanID  = 2;

bootstrap/mocks/things.go

@@ -218,6 +218,10 @@ func (svc *mainfluxThings) CanAccessByID(context.Context, string, string) error
 	panic("not implemented")
 }
 
+func (svc *mainfluxThings) IsChannelOwner(context.Context, string, string) error {
+	panic("not implemented")
+}
+
 func (svc *mainfluxThings) Identify(context.Context, string) (string, error) {
 	panic("not implemented")
 }

http/mocks/things.go

@@ -54,6 +54,10 @@ func (tc thingsClient) CanAccessByID(context.Context, *mainflux.AccessByIDReq, .
 	panic("not implemented")
 }
 
+func (tc thingsClient) IsChannelOwner(context.Context, *mainflux.ChannelOwnerReq, ...grpc.CallOption) (*empty.Empty, error) {
+	panic("not implemented")
+}
+
 func (tc thingsClient) Identify(ctx context.Context, req *mainflux.Token, opts ...grpc.CallOption) (*mainflux.ThingID, error) {
 	panic("not implemented")
 }

readers/mocks/things.go

@@ -42,6 +42,10 @@ func (svc thingsServiceMock) CanAccessByID(context.Context, *mainflux.AccessByID
 	panic("not implemented")
 }
 
+func (svc thingsServiceMock) IsChannelOwner(context.Context, *mainflux.ChannelOwnerReq, ...grpc.CallOption) (*empty.Empty, error) {
+	panic("not implemented")
+}
+
 func (svc thingsServiceMock) Identify(context.Context, *mainflux.Token, ...grpc.CallOption) (*mainflux.ThingID, error) {
 	panic("not implemented")
 }

scripts/ci.sh

@@ -1,7 +1,7 @@
 # This script contains commands to be executed by the CI tool.
 NPROC=$(nproc)
 GO_VERSION=1.14.4
-PROTOC_VERSION=3.11.4
+PROTOC_VERSION=3.12.3
 PROTOC_GEN_VERSION=v1.4.2
 PROTOC_GOFAST_VERSION=v1.3.1
 GRPC_VERSION=v1.29.1

things/api/auth/grpc/client.go

@@ -22,6 +22,7 @@ type grpcClient struct {
 	timeout        time.Duration
 	canAccessByKey endpoint.Endpoint
 	canAccessByID  endpoint.Endpoint
+	isChannelOwner endpoint.Endpoint
 	identify       endpoint.Endpoint
 }
 
@@ -47,6 +48,14 @@ func NewClient(conn *grpc.ClientConn, tracer opentracing.Tracer, timeout time.Du
 			decodeEmptyResponse,
 			empty.Empty{},
 		).Endpoint()),
+		isChannelOwner: kitot.TraceClient(tracer, "is_channel_owner")(kitgrpc.NewClient(
+			conn,
+			svcName,
+			"IsChannelOwner",
+			encodeIsChannelOwner,
+			decodeEmptyResponse,
+			empty.Empty{},
+		).Endpoint()),
 		identify: kitot.TraceClient(tracer, "identify")(kitgrpc.NewClient(
 			conn,
 			svcName,
@@ -86,6 +95,17 @@ func (client grpcClient) CanAccessByID(ctx context.Context, req *mainflux.Access
 	return &empty.Empty{}, er.err
 }
 
+func (client grpcClient) IsChannelOwner(ctx context.Context, req *mainflux.ChannelOwnerReq, _ ...grpc.CallOption) (*empty.Empty, error) {
+	ar := channelOwnerReq{owner: req.GetOwner(), chanID: req.GetChanID()}
+	res, err := client.isChannelOwner(ctx, ar)
+	if err != nil {
+		return nil, err
+	}
+
+	er := res.(emptyRes)
+	return &empty.Empty{}, er.err
+}
+
 func (client grpcClient) Identify(ctx context.Context, req *mainflux.Token, _ ...grpc.CallOption) (*mainflux.ThingID, error) {
 	ctx, cancel := context.WithTimeout(ctx, client.timeout)
 	defer cancel()
@@ -109,6 +129,11 @@ func encodeCanAccessByIDRequest(_ context.Context, grpcReq interface{}) (interfa
 	return &mainflux.AccessByIDReq{ThingID: req.thingID, ChanID: req.chanID}, nil
 }
 
+func encodeIsChannelOwner(_ context.Context, grpcReq interface{}) (interface{}, error) {
+	req := grpcReq.(channelOwnerReq)
+	return &mainflux.ChannelOwnerReq{Owner: req.owner, ChanID: req.chanID}, nil
+}
+
 func encodeIdentifyRequest(_ context.Context, grpcReq interface{}) (interface{}, error) {
 	req := grpcReq.(identifyReq)
 	return &mainflux.Token{Value: req.key}, nil

things/api/auth/grpc/endpoint.go

@@ -37,6 +37,18 @@ func canAccessByIDEndpoint(svc things.Service) endpoint.Endpoint {
 	}
 }
 
+func isChannelOwnerEndpoint(svc things.Service) endpoint.Endpoint {
+	return func(ctx context.Context, request interface{}) (interface{}, error) {
+		req := request.(channelOwnerReq)
+		if err := req.validate(); err != nil {
+			return nil, err
+		}
+
+		err := svc.IsChannelOwner(ctx, req.chanID, req.owner)
+		return emptyRes{err: err}, err
+	}
+}
+
 func identifyEndpoint(svc things.Service) endpoint.Endpoint {
 	return func(ctx context.Context, request interface{}) (interface{}, error) {
 		req := request.(identifyReq)

things/api/auth/grpc/requests.go

@@ -31,6 +31,19 @@ func (req accessByIDReq) validate() error {
 	return nil
 }
 
+type channelOwnerReq struct {
+	owner  string
+	chanID string
+}
+
+func (req channelOwnerReq) validate() error {
+	if req.owner == "" || req.chanID == "" {
+		return things.ErrMalformedEntity
+	}
+
+	return nil
+}
+
 type identifyReq struct {
 	key string
 }

things/api/auth/grpc/server.go

@@ -21,6 +21,7 @@ var _ mainflux.ThingsServiceServer = (*grpcServer)(nil)
 type grpcServer struct {
 	canAccessByKey kitgrpc.Handler
 	canAccessByID  kitgrpc.Handler
+	isChannelOwner kitgrpc.Handler
 	identify       kitgrpc.Handler
 }
 
@@ -37,6 +38,11 @@ func NewServer(tracer opentracing.Tracer, svc things.Service) mainflux.ThingsSer
 			decodeCanAccessByIDRequest,
 			encodeEmptyResponse,
 		),
+		isChannelOwner: kitgrpc.NewServer(
+			isChannelOwnerEndpoint(svc),
+			decodeIsChannelOwnerRequest,
+			encodeEmptyResponse,
+		),
 		identify: kitgrpc.NewServer(
 			kitot.TraceServer(tracer, "identify")(identifyEndpoint(svc)),
 			decodeIdentifyRequest,
@@ -63,6 +69,15 @@ func (gs *grpcServer) CanAccessByID(ctx context.Context, req *mainflux.AccessByI
 	return res.(*empty.Empty), nil
 }
 
+func (gs *grpcServer) IsChannelOwner(ctx context.Context, req *mainflux.ChannelOwnerReq) (*empty.Empty, error) {
+	_, res, err := gs.isChannelOwner.ServeGRPC(ctx, req)
+	if err != nil {
+		return nil, encodeError(err)
+	}
+
+	return res.(*empty.Empty), nil
+}
+
 func (gs *grpcServer) Identify(ctx context.Context, req *mainflux.Token) (*mainflux.ThingID, error) {
 	_, res, err := gs.identify.ServeGRPC(ctx, req)
 	if err != nil {
@@ -82,6 +97,11 @@ func decodeCanAccessByIDRequest(_ context.Context, grpcReq interface{}) (interfa
 	return accessByIDReq{thingID: req.GetThingID(), chanID: req.GetChanID()}, nil
 }
 
+func decodeIsChannelOwnerRequest(_ context.Context, grpcReq interface{}) (interface{}, error) {
+	req := grpcReq.(*mainflux.ChannelOwnerReq)
+	return channelOwnerReq{owner: req.GetOwner(), chanID: req.GetChanID()}, nil
+}
+
 func decodeIdentifyRequest(_ context.Context, grpcReq interface{}) (interface{}, error) {
 	req := grpcReq.(*mainflux.Token)
 	return identifyReq{key: req.GetValue()}, nil

things/api/logging.go

@@ -253,6 +253,20 @@ func (lm *loggingMiddleware) CanAccessByID(ctx context.Context, chanID, thingID
 
 	return lm.svc.CanAccessByID(ctx, chanID, thingID)
 }
+
+func (lm *loggingMiddleware) IsChannelOwner(ctx context.Context, owner, chanID string) (err error) {
+	defer func(begin time.Time) {
+		message := fmt.Sprintf("Method is_channel_owner for channel %s and user %s took %s to complete", chanID, owner, time.Since(begin))
+		if err != nil {
+			lm.logger.Warn(fmt.Sprintf("%s with error: %s.", message, err))
+			return
+		}
+		lm.logger.Info(fmt.Sprintf("%s without errors.", message))
+	}(time.Now())
+
+	return lm.svc.IsChannelOwner(ctx, owner, chanID)
+}
+
 func (lm *loggingMiddleware) Identify(ctx context.Context, key string) (id string, err error) {
 	defer func(begin time.Time) {
 		message := fmt.Sprintf("Method identify for token %s and thing %s took %s to complete", key, id, time.Since(begin))

things/api/metrics.go

@@ -184,6 +184,15 @@ func (ms *metricsMiddleware) CanAccessByID(ctx context.Context, chanID, thingID
 	return ms.svc.CanAccessByID(ctx, chanID, thingID)
 }
 
+func (ms *metricsMiddleware) IsChannelOwner(ctx context.Context, owner, chanID string) error {
+	defer func(begin time.Time) {
+		ms.counter.With("method", "is_channel_owner").Add(1)
+		ms.latency.With("method", "is_channel_owner").Observe(time.Since(begin).Seconds())
+	}(time.Now())
+
+	return ms.svc.CanAccessByID(ctx, owner, chanID)
+}
+
 func (ms *metricsMiddleware) Identify(ctx context.Context, key string) (string, error) {
 	defer func(begin time.Time) {
 		ms.counter.With("method", "identify").Add(1)

things/redis/streams.go

@@ -237,6 +237,10 @@ func (es eventStore) CanAccessByID(ctx context.Context, chanID string, thingID s
 	return es.svc.CanAccessByID(ctx, chanID, thingID)
 }
 
+func (es eventStore) IsChannelOwner(ctx context.Context, owner, chanID string) error {
+	return es.svc.IsChannelOwner(ctx, owner, chanID)
+}
+
 func (es eventStore) Identify(ctx context.Context, key string) (string, error) {
 	return es.svc.Identify(ctx, key)
 }

things/service.go

@@ -54,7 +54,7 @@ var (
 // Service specifies an API that must be fullfiled by the domain service
 // implementation, and all of its decorators (e.g. logging & metrics).
 type Service interface {
-	// CreateThings adds a list of things to the user identified by the provided key.
+	// CreateThings adds things to the user identified by the provided key.
 	CreateThings(ctx context.Context, token string, things ...Thing) ([]Thing, error)
 
 	// UpdateThing updates the thing identified by the provided ID, that
@@ -82,7 +82,7 @@ type Service interface {
 	// belongs to the user identified by the provided key.
 	RemoveThing(ctx context.Context, token, id string) error
 
-	// CreateChannels adds a list of channels to the user identified by the provided key.
+	// CreateChannels adds channels to the user identified by the provided key.
 	CreateChannels(ctx context.Context, token string, channels ...Channel) ([]Channel, error)
 
 	// UpdateChannel updates the channel identified by the provided ID, that
@@ -121,6 +121,10 @@ type Service interface {
 	// the given thing and returns error if it cannot.
 	CanAccessByID(ctx context.Context, chanID, thingID string) error
 
+	// IsChannelOwner determines whether the channel can be accessed by
+	// the given user and returns error if it cannot.
+	IsChannelOwner(ctx context.Context, owner, chanID string) error
+
 	// Identify returns thing ID for given thing key.
 	Identify(ctx context.Context, key string) (string, error)
 
@@ -377,6 +381,13 @@ func (ts *thingsService) CanAccessByID(ctx context.Context, chanID, thingID stri
 	return nil
 }
 
+func (ts *thingsService) IsChannelOwner(ctx context.Context, owner, chanID string) error {
+	if _, err := ts.channels.RetrieveByID(ctx, owner, chanID); err != nil {
+		return err
+	}
+	return nil
+}
+
 func (ts *thingsService) Identify(ctx context.Context, key string) (string, error) {
 	id, err := ts.thingCache.ID(ctx, key)
 	if err == nil {
@@ -431,7 +442,6 @@ func (ts *thingsService) ListGroups(ctx context.Context, token string, level uin
 		return groups.GroupPage{}, errors.Wrap(ErrUnauthorizedAccess, err)
 	}
 	return ts.groups.RetrieveAll(ctx, level, gm)
-
 }
 
 func (ts *thingsService) ListParents(ctx context.Context, token string, childID string, level uint64, gm groups.Metadata) (groups.GroupPage, error) {

things/service_test.go

@@ -22,6 +22,7 @@ const (
 	wrongValue = "wrong-value"
 	email      = "user@example.com"
 	token      = "token"
+	token2     = "token2"
 	n          = uint64(10)
 )
 
@@ -1232,6 +1233,40 @@ func TestCanAccessByID(t *testing.T) {
 	}
 }
 
+func TestIsChannelOwner(t *testing.T) {
+	svc := newService(map[string]string{token: email, token2: "john.doe@email.net"})
+
+	chs, err := svc.CreateChannels(context.Background(), token, channel)
+	require.Nil(t, err, fmt.Sprintf("unexpected error: %s\n", err))
+	ownedCh := chs[0]
+	chs, err = svc.CreateChannels(context.Background(), token2, channel)
+	require.Nil(t, err, fmt.Sprintf("unexpected error: %s\n", err))
+	nonOwnedCh := chs[0]
+
+	cases := map[string]struct {
+		channel string
+		err     error
+	}{
+		"user owns channel": {
+			channel: ownedCh.ID,
+			err:     nil,
+		},
+		"user does not own channel": {
+			channel: nonOwnedCh.ID,
+			err:     things.ErrNotFound,
+		},
+		"access to non-existing channel": {
+			channel: wrongID,
+			err:     things.ErrNotFound,
+		},
+	}
+
+	for desc, tc := range cases {
+		err := svc.IsChannelOwner(context.Background(), email, tc.channel)
+		assert.True(t, errors.Contains(err, tc.err), fmt.Sprintf("%s: expected %s got %s\n", desc, tc.err, err))
+	}
+}
+
 func TestIdentify(t *testing.T) {
 	svc := newService(map[string]string{token: email})