package lfs import ( "encoding/base64" "encoding/json" "fmt" "io" "net/http" "regexp" "strconv" "strings" "time" "code.gitea.io/gitea/models" "code.gitea.io/gitea/modules/context" "code.gitea.io/gitea/modules/log" "code.gitea.io/gitea/modules/setting" "github.com/dgrijalva/jwt-go" "gopkg.in/macaron.v1" ) const ( contentMediaType = "application/vnd.git-lfs" metaMediaType = contentMediaType + "+json" ) // RequestVars contain variables from the HTTP request. Variables from routing, json body decoding, and // some headers are stored. type RequestVars struct { Oid string Size int64 User string Password string Repo string Authorization string } // BatchVars contains multiple RequestVars processed in one batch operation. // https://github.com/git-lfs/git-lfs/blob/master/docs/api/batch.md type BatchVars struct { Transfers []string `json:"transfers,omitempty"` Operation string `json:"operation"` Objects []*RequestVars `json:"objects"` } // BatchResponse contains multiple object metadata Representation structures // for use with the batch API. type BatchResponse struct { Transfer string `json:"transfer,omitempty"` Objects []*Representation `json:"objects"` } // Representation is object metadata as seen by clients of the lfs server. type Representation struct { Oid string `json:"oid"` Size int64 `json:"size"` Actions map[string]*link `json:"actions"` Error *ObjectError `json:"error,omitempty"` } // ObjectError defines the JSON structure returned to the client in case of an error type ObjectError struct { Code int `json:"code"` Message string `json:"message"` } // ObjectLink builds a URL linking to the object. func (v *RequestVars) ObjectLink() string { return fmt.Sprintf("%s%s/%s/info/lfs/objects/%s", setting.AppURL, v.User, v.Repo, v.Oid) } // link provides a structure used to build a hypermedia representation of an HTTP link. type link struct { Href string `json:"href"` Header map[string]string `json:"header,omitempty"` ExpiresAt time.Time `json:"expires_at,omitempty"` } // ObjectOidHandler is the main request routing entry point into LFS server functions func ObjectOidHandler(ctx *context.Context) { if !setting.LFS.StartServer { writeStatus(ctx, 404) return } if ctx.Req.Method == "GET" || ctx.Req.Method == "HEAD" { if MetaMatcher(ctx.Req) { GetMetaHandler(ctx) return } if ContentMatcher(ctx.Req) || len(ctx.Params("filename")) > 0 { GetContentHandler(ctx) return } } else if ctx.Req.Method == "PUT" && ContentMatcher(ctx.Req) { PutHandler(ctx) return } } // GetContentHandler gets the content from the content store func GetContentHandler(ctx *context.Context) { rv := unpack(ctx) meta, err := models.GetLFSMetaObjectByOid(rv.Oid) if err != nil { writeStatus(ctx, 404) return } repository, err := models.GetRepositoryByID(meta.RepositoryID) if err != nil { writeStatus(ctx, 404) return } if !authenticate(ctx, repository, rv.Authorization, false) { requireAuth(ctx) return } // Support resume download using Range header var fromByte int64 statusCode := 200 if rangeHdr := ctx.Req.Header.Get("Range"); rangeHdr != "" { regex := regexp.MustCompile(`bytes=(\d+)\-.*`) match := regex.FindStringSubmatch(rangeHdr) if match != nil && len(match) > 1 { statusCode = 206 fromByte, _ = strconv.ParseInt(match[1], 10, 32) ctx.Resp.Header().Set("Content-Range", fmt.Sprintf("bytes %d-%d/%d", fromByte, meta.Size-1, meta.Size-fromByte)) } } contentStore := &ContentStore{BasePath: setting.LFS.ContentPath} content, err := contentStore.Get(meta, fromByte) if err != nil { writeStatus(ctx, 404) return } ctx.Resp.Header().Set("Content-Length", strconv.FormatInt(meta.Size, 10)) ctx.Resp.Header().Set("Content-Type", "application/octet-stream") filename := ctx.Params("filename") if len(filename) > 0 { decodedFilename, err := base64.RawURLEncoding.DecodeString(filename) if err == nil { ctx.Resp.Header().Set("Content-Disposition", "attachment; filename=\""+string(decodedFilename)+"\"") } } ctx.Resp.WriteHeader(statusCode) io.Copy(ctx.Resp, content) content.Close() logRequest(ctx.Req, statusCode) } // GetMetaHandler retrieves metadata about the object func GetMetaHandler(ctx *context.Context) { rv := unpack(ctx) meta, err := models.GetLFSMetaObjectByOid(rv.Oid) if err != nil { writeStatus(ctx, 404) return } repository, err := models.GetRepositoryByID(meta.RepositoryID) if err != nil { writeStatus(ctx, 404) return } if !authenticate(ctx, repository, rv.Authorization, false) { requireAuth(ctx) return } ctx.Resp.Header().Set("Content-Type", metaMediaType) if ctx.Req.Method == "GET" { enc := json.NewEncoder(ctx.Resp) enc.Encode(Represent(rv, meta, true, false)) } logRequest(ctx.Req, 200) } // PostHandler instructs the client how to upload data func PostHandler(ctx *context.Context) { if !setting.LFS.StartServer { writeStatus(ctx, 404) return } if !MetaMatcher(ctx.Req) { writeStatus(ctx, 400) return } rv := unpack(ctx) repositoryString := rv.User + "/" + rv.Repo repository, err := models.GetRepositoryByRef(repositoryString) if err != nil { log.Debug("Could not find repository: %s - %s", repositoryString, err) writeStatus(ctx, 404) return } if !authenticate(ctx, repository, rv.Authorization, true) { requireAuth(ctx) } meta, err := models.NewLFSMetaObject(&models.LFSMetaObject{Oid: rv.Oid, Size: rv.Size, RepositoryID: repository.ID}) if err != nil { writeStatus(ctx, 404) return } ctx.Resp.Header().Set("Content-Type", metaMediaType) sentStatus := 202 contentStore := &ContentStore{BasePath: setting.LFS.ContentPath} if meta.Existing && contentStore.Exists(meta) { sentStatus = 200 } ctx.Resp.WriteHeader(sentStatus) enc := json.NewEncoder(ctx.Resp) enc.Encode(Represent(rv, meta, meta.Existing, true)) logRequest(ctx.Req, sentStatus) } // BatchHandler provides the batch api func BatchHandler(ctx *context.Context) { if !setting.LFS.StartServer { writeStatus(ctx, 404) return } if !MetaMatcher(ctx.Req) { writeStatus(ctx, 400) return } bv := unpackbatch(ctx) var responseObjects []*Representation // Create a response object for _, object := range bv.Objects { repositoryString := object.User + "/" + object.Repo repository, err := models.GetRepositoryByRef(repositoryString) if err != nil { log.Debug("Could not find repository: %s - %s", repositoryString, err) writeStatus(ctx, 404) return } requireWrite := false if bv.Operation == "upload" { requireWrite = true } if !authenticate(ctx, repository, object.Authorization, requireWrite) { requireAuth(ctx) return } meta, err := models.GetLFSMetaObjectByOid(object.Oid) contentStore := &ContentStore{BasePath: setting.LFS.ContentPath} if err == nil && contentStore.Exists(meta) { // Object is found and exists responseObjects = append(responseObjects, Represent(object, meta, true, false)) continue } // Object is not found meta, err = models.NewLFSMetaObject(&models.LFSMetaObject{Oid: object.Oid, Size: object.Size, RepositoryID: repository.ID}) if err == nil { responseObjects = append(responseObjects, Represent(object, meta, meta.Existing, true)) } } ctx.Resp.Header().Set("Content-Type", metaMediaType) respobj := &BatchResponse{Objects: responseObjects} enc := json.NewEncoder(ctx.Resp) enc.Encode(respobj) logRequest(ctx.Req, 200) } // PutHandler receives data from the client and puts it into the content store func PutHandler(ctx *context.Context) { rv := unpack(ctx) meta, err := models.GetLFSMetaObjectByOid(rv.Oid) if err != nil { writeStatus(ctx, 404) return } repository, err := models.GetRepositoryByID(meta.RepositoryID) if err != nil { writeStatus(ctx, 404) return } if !authenticate(ctx, repository, rv.Authorization, true) { requireAuth(ctx) return } contentStore := &ContentStore{BasePath: setting.LFS.ContentPath} if err := contentStore.Put(meta, ctx.Req.Body().ReadCloser()); err != nil { models.RemoveLFSMetaObjectByOid(rv.Oid) ctx.Resp.WriteHeader(500) fmt.Fprintf(ctx.Resp, `{"message":"%s"}`, err) return } logRequest(ctx.Req, 200) } // Represent takes a RequestVars and Meta and turns it into a Representation suitable // for json encoding func Represent(rv *RequestVars, meta *models.LFSMetaObject, download, upload bool) *Representation { rep := &Representation{ Oid: meta.Oid, Size: meta.Size, Actions: make(map[string]*link), } header := make(map[string]string) header["Accept"] = contentMediaType if rv.Authorization == "" { //https://github.com/github/git-lfs/issues/1088 header["Authorization"] = "Authorization: Basic dummy" } else { header["Authorization"] = rv.Authorization } if download { rep.Actions["download"] = &link{Href: rv.ObjectLink(), Header: header} } if upload { rep.Actions["upload"] = &link{Href: rv.ObjectLink(), Header: header} } return rep } // ContentMatcher provides a mux.MatcherFunc that only allows requests that contain // an Accept header with the contentMediaType func ContentMatcher(r macaron.Request) bool { mediaParts := strings.Split(r.Header.Get("Accept"), ";") mt := mediaParts[0] return mt == contentMediaType } // MetaMatcher provides a mux.MatcherFunc that only allows requests that contain // an Accept header with the metaMediaType func MetaMatcher(r macaron.Request) bool { mediaParts := strings.Split(r.Header.Get("Accept"), ";") mt := mediaParts[0] return mt == metaMediaType } func unpack(ctx *context.Context) *RequestVars { r := ctx.Req rv := &RequestVars{ User: ctx.Params("username"), Repo: strings.TrimSuffix(ctx.Params("reponame"), ".git"), Oid: ctx.Params("oid"), Authorization: r.Header.Get("Authorization"), } if r.Method == "POST" { // Maybe also check if +json var p RequestVars dec := json.NewDecoder(r.Body().ReadCloser()) err := dec.Decode(&p) if err != nil { return rv } rv.Oid = p.Oid rv.Size = p.Size } return rv } // TODO cheap hack, unify with unpack func unpackbatch(ctx *context.Context) *BatchVars { r := ctx.Req var bv BatchVars dec := json.NewDecoder(r.Body().ReadCloser()) err := dec.Decode(&bv) if err != nil { return &bv } for i := 0; i < len(bv.Objects); i++ { bv.Objects[i].User = ctx.Params("username") bv.Objects[i].Repo = strings.TrimSuffix(ctx.Params("reponame"), ".git") bv.Objects[i].Authorization = r.Header.Get("Authorization") } return &bv } func writeStatus(ctx *context.Context, status int) { message := http.StatusText(status) mediaParts := strings.Split(ctx.Req.Header.Get("Accept"), ";") mt := mediaParts[0] if strings.HasSuffix(mt, "+json") { message = `{"message":"` + message + `"}` } ctx.Resp.WriteHeader(status) fmt.Fprint(ctx.Resp, message) logRequest(ctx.Req, status) } func logRequest(r macaron.Request, status int) { log.Debug("LFS request - Method: %s, URL: %s, Status %d", r.Method, r.URL, status) } // authenticate uses the authorization string to determine whether // or not to proceed. This server assumes an HTTP Basic auth format. func authenticate(ctx *context.Context, repository *models.Repository, authorization string, requireWrite bool) bool { accessMode := models.AccessModeRead if requireWrite { accessMode = models.AccessModeWrite } if !repository.IsPrivate && !requireWrite { return true } if ctx.IsSigned { accessCheck, _ := models.HasAccess(ctx.User.ID, repository, accessMode) return accessCheck } if authorization == "" { return false } if authenticateToken(repository, authorization, requireWrite) { return true } if !strings.HasPrefix(authorization, "Basic ") { return false } c, err := base64.StdEncoding.DecodeString(strings.TrimPrefix(authorization, "Basic ")) if err != nil { return false } cs := string(c) i := strings.IndexByte(cs, ':') if i < 0 { return false } user, password := cs[:i], cs[i+1:] userModel, err := models.GetUserByName(user) if err != nil { return false } if !userModel.ValidatePassword(password) { return false } accessCheck, _ := models.HasAccess(userModel.ID, repository, accessMode) return accessCheck } func authenticateToken(repository *models.Repository, authorization string, requireWrite bool) bool { if !strings.HasPrefix(authorization, "Bearer ") { return false } token, err := jwt.Parse(authorization[7:], func(t *jwt.Token) (interface{}, error) { if _, ok := t.Method.(*jwt.SigningMethodHMAC); !ok { return nil, fmt.Errorf("unexpected signing method: %v", t.Header["alg"]) } return setting.LFS.JWTSecretBytes, nil }) if err != nil { return false } claims, claimsOk := token.Claims.(jwt.MapClaims) if !token.Valid || !claimsOk { return false } opStr, ok := claims["op"].(string) if !ok { return false } if requireWrite && opStr != "upload" { return false } repoID, ok := claims["repo"].(float64) if !ok { return false } if repository.ID != int64(repoID) { return false } return true } func requireAuth(ctx *context.Context) { ctx.Resp.Header().Set("WWW-Authenticate", "Basic realm=gitea-lfs") writeStatus(ctx, 401) }