Small refactorings of rpc package

mtproto/rpc/rpc_nonce_response.go

@@ -6,36 +6,33 @@ import (
 	"github.com/juju/errors"
 )
 
-const rpcNonceResponseLength = rpcNonceRequestLength
-
 type RPCNonceResponse struct {
 	RPCNonceRequest
 
-	RPCType [rpcNonceTagLength]byte
-	Crypto  [rpcNonceCryptoAESLength]byte
+	RPCType []byte
+	Crypto  []byte
 }
 
 func (r *RPCNonceResponse) Bytes() []byte {
 	buf := &bytes.Buffer{}
-	buf.Grow(rpcNonceResponseLength)
 
-	buf.Write(r.RPCType[:])
-	buf.Write(r.KeySelector[:])
-	buf.Write(r.Crypto[:])
-	buf.Write(r.CryptoTS[:])
-	buf.Write(r.Nonce[:])
+	buf.Write(r.RPCType)
+	buf.Write(r.KeySelector)
+	buf.Write(r.Crypto)
+	buf.Write(r.CryptoTS)
+	buf.Write(r.Nonce)
 
 	return buf.Bytes()
 }
 
 func (r *RPCNonceResponse) Valid(req *RPCNonceRequest) error {
-	if r.RPCType != rpcNonceTag {
+	if !bytes.Equal(r.RPCType, RPCTagNonce) {
 		return errors.New("Unexpected RPC type")
 	}
-	if r.Crypto != rpcNonceCryptoAESTag {
+	if !bytes.Equal(r.Crypto, RPCNonceCryptoAES) {
 		return errors.New("Unexpected crypto type")
 	}
-	if r.KeySelector != req.KeySelector {
+	if !bytes.Equal(r.KeySelector, req.KeySelector) {
 		return errors.New("Unexpected key selector")
 	}
 
@@ -43,16 +40,17 @@ func (r *RPCNonceResponse) Valid(req *RPCNonceRequest) error {
 }
 
 func NewRPCNonceResponse(data []byte) (*RPCNonceResponse, error) {
-	if len(data) != rpcNonceResponseLength {
+	if len(data) != 32 {
 		return nil, errors.New("Unexpected message length")
 	}
 
-	resp := RPCNonceResponse{}
-	copy(resp.RPCType[:], data[:4])
-	copy(resp.KeySelector[:], data[4:8])
-	copy(resp.Crypto[:], data[8:12])
-	copy(resp.CryptoTS[:], data[12:16])
-	copy(resp.Nonce[:], data[16:])
-
-	return &resp, nil
+	return &RPCNonceResponse{
+		RPCNonceRequest: RPCNonceRequest{
+			KeySelector: data[4:8],
+			CryptoTS:    data[12:16],
+			Nonce:       data[16:],
+		},
+		RPCType: data[:4],
+		Crypto:  data[8:12],
+	}, nil
 }