// Copyright 2015 The Gogs Authors. All rights reserved.// SPDX-License-Identifier: MIT package git import (	"bytes"	"strings" 	api "forgejo.org/modules/structs"	"forgejo.org/modules/util") const (	beginpgp = "\n-----BEGIN PGP SIGNATURE-----\n"	endpgp   = "\n-----END PGP SIGNATURE-----"	beginssh = "\n-----BEGIN SSH SIGNATURE-----\n"	endssh   = "\n-----END SSH SIGNATURE-----") // Tag represents a Git tag.type Tag struct {	Name                 string	ID                   ObjectID	Object               ObjectID // The id of this commit object	Type                 string	Tagger               *Signature	Message              string	Signature            *ObjectSignature	ArchiveDownloadCount *api.TagArchiveDownloadCount} // Commit return the commit of the tag referencefunc (tag *Tag) Commit(gitRepo *Repository) (*Commit, error) {	return gitRepo.getCommit(tag.Object)} // Parse commit information from the (uncompressed) raw// data from the commit object.// \n\n separate headers from messagefunc parseTagData(objectFormat ObjectFormat, data []byte) (*Tag, error) {	tag := new(Tag)	tag.ID = objectFormat.EmptyObjectID()	tag.Object = objectFormat.EmptyObjectID()	tag.Tagger = &Signature{}	// we now have the contents of the commit object. Let's investigate...	nextline := 0l:	for {		eol := bytes.IndexByte(data[nextline:], '\n')		switch {		case eol > 0:			line := data[nextline : nextline+eol]			spacepos := bytes.IndexByte(line, ' ')			reftype := line[:spacepos]			switch string(reftype) {			case "object":				id, err := NewIDFromString(string(line[spacepos+1:]))				if err != nil {					return nil, err				}				tag.Object = id			case "type":				// A commit can have one or more parents				tag.Type = string(line[spacepos+1:])			case "tagger":				tag.Tagger = parseSignatureFromCommitLine(util.UnsafeBytesToString(line[spacepos+1:]))			}			nextline += eol + 1		case eol == 0:			tag.Message = string(data[nextline+1:])			break l		default:			break l		}	} 	extractTagSignature := func(signatureBeginMark, signatureEndMark string) (bool, *ObjectSignature, string) {		idx := strings.LastIndex(tag.Message, signatureBeginMark)		if idx == -1 {			return false, nil, ""		} 		endSigIdx := strings.Index(tag.Message[idx:], signatureEndMark)		if endSigIdx == -1 {			return false, nil, ""		} 		return true, &ObjectSignature{			Signature: tag.Message[idx+1 : idx+endSigIdx+len(signatureEndMark)],			Payload:   string(data[:bytes.LastIndex(data, []byte(signatureBeginMark))+1]),		}, tag.Message[:idx+1]	} 	// Try to find an OpenPGP signature	found, sig, message := extractTagSignature(beginpgp, endpgp)	if !found {		// If not found, try an SSH one		found, sig, message = extractTagSignature(beginssh, endssh)	}	// If either is found, update the tag Signature and Message	if found {		tag.Signature = sig		tag.Message = message	} 	return tag, nil}