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: certs.go
    path of file: ./repos/malice/vendor/golang.org/x/crypto/ssh
    
    the code of the file until where you have to start completion: // Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package ssh

import (
	"bytes"
	"errors"
	"fmt"
	"io"
	"net"
	"sort"
	"time"
)

// These constants from [PROTOCOL.certkeys] represent the algorithm names
// for certificate types supported by this package.
const (
	CertAlgoRSAv01      = "ssh-rsa-cert
    
func parseTuples(in []byte) (map[string]string, error) {
	tups := map[string]string{}
	var lastKey string
	var haveLastKey bool

	for len(in) > 0 {
		var key, val, extra []byte
		var ok bool

		if key, in, ok = parseString(in); !ok {
			return nil, errShortRead
		}
		keyStr := string(key)
		// according to [PROTOCOL.certkeys], the names must be in
		// lexical order.
		if haveLastKey && keyStr <= lastKey {
			return nil, fmt.Errorf("ssh: certificate options are not in lexical order")
		}
		lastKey, haveLastKey = keyStr, true
		// the next field is a data field, which if non-empty has a string embedded
		if val, in, ok = parseString(in); !ok {
			return nil, errShortRead
		}
		if len(val) > 0 {
			val, extra, ok = parseString(val)
			if !ok {
				return nil, errShortRead
			}
			if len(extra) > 0 {
				return nil, fmt.Errorf("ssh: unexpected trailing data after certificate option value")
			}
			tups[keyStr] = string(val)
		} else {
			tups[keyStr] = ""
		}
	}
	return tups, nil
}