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gitea-fork-majority-judgment/modules/lfs/server.go

571 lines
14 KiB

package lfs
import (
"encoding/base64"
"encoding/json"
"fmt"
"io"
"net/http"
"path"
"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 setting.AppURL + path.Join(v.User, v.Repo+".git", "info/lfs/objects", v.Oid)
}
// VerifyLink builds a URL for verifying the object.
func (v *RequestVars) VerifyLink() string {
return setting.AppURL + path.Join(v.User, v.Repo+".git", "info/lfs/verify")
}
// 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
}
}
func getAuthenticatedRepoAndMeta(ctx *context.Context, rv *RequestVars, requireWrite bool) (*models.LFSMetaObject, *models.Repository) {
repository, err := models.GetRepositoryByOwnerAndName(rv.User, rv.Repo)
if err != nil {
log.Debug("Could not find repository: %s/%s - %s", rv.User, rv.Repo, err)
writeStatus(ctx, 404)
return nil, nil
}
if !authenticate(ctx, repository, rv.Authorization, requireWrite) {
requireAuth(ctx)
return nil, nil
}
meta, err := repository.GetLFSMetaObjectByOid(rv.Oid)
if err != nil {
writeStatus(ctx, 404)
return nil, nil
}
return meta, repository
}
// getContentHandler gets the content from the content store
func getContentHandler(ctx *context.Context) {
rv := unpack(ctx)
meta, _ := getAuthenticatedRepoAndMeta(ctx, rv, false)
if meta == nil {
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-fromByte, 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, _ := getAuthenticatedRepoAndMeta(ctx, rv, false)
if meta == nil {
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)
repository, err := models.GetRepositoryByOwnerAndName(rv.User, rv.Repo)
if err != nil {
log.Debug("Could not find repository: %s/%s - %s", rv.User, rv.Repo, 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 {
repository, err := models.GetRepositoryByOwnerAndName(object.User, object.Repo)
if err != nil {
log.Debug("Could not find repository: %s/%s - %s", object.User, object.Repo, err)
writeStatus(ctx, 404)
return
}
requireWrite := false
if bv.Operation == "upload" {
requireWrite = true
}
if !authenticate(ctx, repository, object.Authorization, requireWrite) {
requireAuth(ctx)
return
}
contentStore := &ContentStore{BasePath: setting.LFS.ContentPath}
meta, err := repository.GetLFSMetaObjectByOid(object.Oid)
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, !contentStore.Exists(meta)))
}
}
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, repository := getAuthenticatedRepoAndMeta(ctx, rv, true)
if meta == nil {
return
}
contentStore := &ContentStore{BasePath: setting.LFS.ContentPath}
if err := contentStore.Put(meta, ctx.Req.Body().ReadCloser()); err != nil {
ctx.Resp.WriteHeader(500)
fmt.Fprintf(ctx.Resp, `{"message":"%s"}`, err)
if err = repository.RemoveLFSMetaObjectByOid(rv.Oid); err != nil {
log.Error(4, "RemoveLFSMetaObjectByOid: %v", err)
}
return
}
logRequest(ctx.Req, 200)
}
// VerifyHandler verify oid and its size from the content store
func VerifyHandler(ctx *context.Context) {
if !setting.LFS.StartServer {
writeStatus(ctx, 404)
return
}
if !ContentMatcher(ctx.Req) {
writeStatus(ctx, 400)
return
}
rv := unpack(ctx)
meta, _ := getAuthenticatedRepoAndMeta(ctx, rv, true)
if meta == nil {
return
}
contentStore := &ContentStore{BasePath: setting.LFS.ContentPath}
ok, err := contentStore.Verify(meta)
if err != nil {
ctx.Resp.WriteHeader(500)
fmt.Fprintf(ctx.Resp, `{"message":"%s"}`, err)
return
}
if !ok {
writeStatus(ctx, 422)
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}
}
if upload && !download {
// Force client side verify action while gitea lacks proper server side verification
rep.Actions["verify"] = &link{Href: rv.VerifyLink(), 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)
}