You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: scramsha256.go
    path of file: ./repos/goldfish/vendor/github.com/SAP/go-hdb/internal/protocol
    
    the code of the file until where you have to start completion: /*
Copyright 2014 SAP SE

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package protocol

//Salted Challenge Response Authentication Mechanism (SCRAM)

import (
	"crypto/hmac"
	"crypto/rand"
	"crypto/sha256"
	"fmt"

	"github.com/SAP/go-hdb/internal/bufio"
)

const (
	clientChallengeSize     = 64
	serverChallengeDataSize = 68
	clientProofDataSize     = 35
	clientProofS
    
func (r *scramsha256InitialReply) read(rd *bufio.Reader) error {
	cnt, err := rd.ReadInt16()
	if err != nil {
		return err
	}

	if err := readMethodName(rd); err != nil {
		return err
	}

	size, err := rd.ReadByte()
	if err != nil {
		return err
	}
	if size != serverChallengeDataSize {
		return fmt.Errorf("invalid server challenge data size %d - %d expected", size, serverChallengeDataSize)
	}

	//server challenge data

	cnt, err = rd.ReadInt16()
	if err != nil {
		return err
	}
	if cnt != 2 {
		return fmt.Errorf("invalid server challenge data field count %d - %d expected", cnt, 2)
	}

	size, err = rd.ReadByte()
	if err != nil {
		return err
	}
	if trace {
		outLogger.Printf("salt size %d", size)
	}

	r.salt = make([]byte, size)
	if err := rd.ReadFull(r.salt); err != nil {
		return err
	}
	if trace {
		outLogger.Printf("salt %v", r.salt)
	}

	size, err = rd.ReadByte()
	if err != nil {
		return err
	}

	r.serverChallenge = make([]byte, size)
	if err := rd.ReadFull(r.serverChallenge); err != nil {
		return err
	}
	if trace {
		outLogger.Printf("server challenge %v", r.serverChallenge)
	}

	return nil
}