distribution/contrib/token-server/main.go
Sebastiaan van Stijn 1d33874951
go.mod: change imports to github.com/distribution/distribution/v3
Go 1.13 and up enforce import paths to be versioned if a project
contains a go.mod and has released v2 or up.

The current v2.x branches (and releases) do not yet have a go.mod,
and therefore are still allowed to be imported with a non-versioned
import path (go modules add a `+incompatible` annotation in that case).

However, now that this project has a `go.mod` file, incompatible
import paths will not be accepted by go modules, and attempting
to use code from this repository will fail.

This patch uses `v3` for the import-paths (not `v2`), because changing
import paths itself is a breaking change, which means that  the
next release should increment the "major" version to comply with
SemVer (as go modules dictate).

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2021-02-08 18:30:46 +01:00

426 lines
12 KiB
Go

package main
import (
"context"
"encoding/json"
"flag"
"math/rand"
"net/http"
"strconv"
"strings"
"time"
dcontext "github.com/distribution/distribution/v3/context"
"github.com/distribution/distribution/v3/registry/api/errcode"
"github.com/distribution/distribution/v3/registry/auth"
_ "github.com/distribution/distribution/v3/registry/auth/htpasswd"
"github.com/docker/libtrust"
"github.com/gorilla/mux"
"github.com/sirupsen/logrus"
)
var (
enforceRepoClass bool
)
func main() {
var (
issuer = &TokenIssuer{}
pkFile string
addr string
debug bool
err error
passwdFile string
realm string
cert string
certKey string
)
flag.StringVar(&issuer.Issuer, "issuer", "distribution-token-server", "Issuer string for token")
flag.StringVar(&pkFile, "key", "", "Private key file")
flag.StringVar(&addr, "addr", "localhost:8080", "Address to listen on")
flag.BoolVar(&debug, "debug", false, "Debug mode")
flag.StringVar(&passwdFile, "passwd", ".htpasswd", "Passwd file")
flag.StringVar(&realm, "realm", "", "Authentication realm")
flag.StringVar(&cert, "tlscert", "", "Certificate file for TLS")
flag.StringVar(&certKey, "tlskey", "", "Certificate key for TLS")
flag.BoolVar(&enforceRepoClass, "enforce-class", false, "Enforce policy for single repository class")
flag.Parse()
if debug {
logrus.SetLevel(logrus.DebugLevel)
}
if pkFile == "" {
issuer.SigningKey, err = libtrust.GenerateECP256PrivateKey()
if err != nil {
logrus.Fatalf("Error generating private key: %v", err)
}
logrus.Debugf("Using newly generated key with id %s", issuer.SigningKey.KeyID())
} else {
issuer.SigningKey, err = libtrust.LoadKeyFile(pkFile)
if err != nil {
logrus.Fatalf("Error loading key file %s: %v", pkFile, err)
}
logrus.Debugf("Loaded private key with id %s", issuer.SigningKey.KeyID())
}
if realm == "" {
logrus.Fatalf("Must provide realm")
}
ac, err := auth.GetAccessController("htpasswd", map[string]interface{}{
"realm": realm,
"path": passwdFile,
})
if err != nil {
logrus.Fatalf("Error initializing access controller: %v", err)
}
// TODO: Make configurable
issuer.Expiration = 15 * time.Minute
ctx := dcontext.Background()
ts := &tokenServer{
issuer: issuer,
accessController: ac,
refreshCache: map[string]refreshToken{},
}
router := mux.NewRouter()
router.Path("/token/").Methods("GET").Handler(handlerWithContext(ctx, ts.getToken))
router.Path("/token/").Methods("POST").Handler(handlerWithContext(ctx, ts.postToken))
if cert == "" {
err = http.ListenAndServe(addr, router)
} else if certKey == "" {
logrus.Fatalf("Must provide certficate (-tlscert) and key (-tlskey)")
} else {
err = http.ListenAndServeTLS(addr, cert, certKey, router)
}
if err != nil {
logrus.Infof("Error serving: %v", err)
}
}
// handlerWithContext wraps the given context-aware handler by setting up the
// request context from a base context.
func handlerWithContext(ctx context.Context, handler func(context.Context, http.ResponseWriter, *http.Request)) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
ctx := dcontext.WithRequest(ctx, r)
logger := dcontext.GetRequestLogger(ctx)
ctx = dcontext.WithLogger(ctx, logger)
handler(ctx, w, r)
})
}
func handleError(ctx context.Context, err error, w http.ResponseWriter) {
ctx, w = dcontext.WithResponseWriter(ctx, w)
if serveErr := errcode.ServeJSON(w, err); serveErr != nil {
dcontext.GetResponseLogger(ctx).Errorf("error sending error response: %v", serveErr)
return
}
dcontext.GetResponseLogger(ctx).Info("application error")
}
var refreshCharacters = []rune("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
const refreshTokenLength = 15
func newRefreshToken() string {
s := make([]rune, refreshTokenLength)
for i := range s {
s[i] = refreshCharacters[rand.Intn(len(refreshCharacters))]
}
return string(s)
}
type refreshToken struct {
subject string
service string
}
type tokenServer struct {
issuer *TokenIssuer
accessController auth.AccessController
refreshCache map[string]refreshToken
}
type tokenResponse struct {
Token string `json:"access_token"`
RefreshToken string `json:"refresh_token,omitempty"`
ExpiresIn int `json:"expires_in,omitempty"`
}
var repositoryClassCache = map[string]string{}
func filterAccessList(ctx context.Context, scope string, requestedAccessList []auth.Access) []auth.Access {
if !strings.HasSuffix(scope, "/") {
scope = scope + "/"
}
grantedAccessList := make([]auth.Access, 0, len(requestedAccessList))
for _, access := range requestedAccessList {
if access.Type == "repository" {
if !strings.HasPrefix(access.Name, scope) {
dcontext.GetLogger(ctx).Debugf("Resource scope not allowed: %s", access.Name)
continue
}
if enforceRepoClass {
if class, ok := repositoryClassCache[access.Name]; ok {
if class != access.Class {
dcontext.GetLogger(ctx).Debugf("Different repository class: %q, previously %q", access.Class, class)
continue
}
} else if strings.EqualFold(access.Action, "push") {
repositoryClassCache[access.Name] = access.Class
}
}
} else if access.Type == "registry" {
if access.Name != "catalog" {
dcontext.GetLogger(ctx).Debugf("Unknown registry resource: %s", access.Name)
continue
}
// TODO: Limit some actions to "admin" users
} else {
dcontext.GetLogger(ctx).Debugf("Skipping unsupported resource type: %s", access.Type)
continue
}
grantedAccessList = append(grantedAccessList, access)
}
return grantedAccessList
}
type acctSubject struct{}
func (acctSubject) String() string { return "acctSubject" }
type requestedAccess struct{}
func (requestedAccess) String() string { return "requestedAccess" }
type grantedAccess struct{}
func (grantedAccess) String() string { return "grantedAccess" }
// getToken handles authenticating the request and authorizing access to the
// requested scopes.
func (ts *tokenServer) getToken(ctx context.Context, w http.ResponseWriter, r *http.Request) {
dcontext.GetLogger(ctx).Info("getToken")
params := r.URL.Query()
service := params.Get("service")
scopeSpecifiers := params["scope"]
var offline bool
if offlineStr := params.Get("offline_token"); offlineStr != "" {
var err error
offline, err = strconv.ParseBool(offlineStr)
if err != nil {
handleError(ctx, ErrorBadTokenOption.WithDetail(err), w)
return
}
}
requestedAccessList := ResolveScopeSpecifiers(ctx, scopeSpecifiers)
authorizedCtx, err := ts.accessController.Authorized(ctx, requestedAccessList...)
if err != nil {
challenge, ok := err.(auth.Challenge)
if !ok {
handleError(ctx, err, w)
return
}
// Get response context.
ctx, w = dcontext.WithResponseWriter(ctx, w)
challenge.SetHeaders(r, w)
handleError(ctx, errcode.ErrorCodeUnauthorized.WithDetail(challenge.Error()), w)
dcontext.GetResponseLogger(ctx).Info("get token authentication challenge")
return
}
ctx = authorizedCtx
username := dcontext.GetStringValue(ctx, "auth.user.name")
ctx = context.WithValue(ctx, acctSubject{}, username)
ctx = dcontext.WithLogger(ctx, dcontext.GetLogger(ctx, acctSubject{}))
dcontext.GetLogger(ctx).Info("authenticated client")
ctx = context.WithValue(ctx, requestedAccess{}, requestedAccessList)
ctx = dcontext.WithLogger(ctx, dcontext.GetLogger(ctx, requestedAccess{}))
grantedAccessList := filterAccessList(ctx, username, requestedAccessList)
ctx = context.WithValue(ctx, grantedAccess{}, grantedAccessList)
ctx = dcontext.WithLogger(ctx, dcontext.GetLogger(ctx, grantedAccess{}))
token, err := ts.issuer.CreateJWT(username, service, grantedAccessList)
if err != nil {
handleError(ctx, err, w)
return
}
dcontext.GetLogger(ctx).Info("authorized client")
response := tokenResponse{
Token: token,
ExpiresIn: int(ts.issuer.Expiration.Seconds()),
}
if offline {
response.RefreshToken = newRefreshToken()
ts.refreshCache[response.RefreshToken] = refreshToken{
subject: username,
service: service,
}
}
ctx, w = dcontext.WithResponseWriter(ctx, w)
w.Header().Set("Content-Type", "application/json")
json.NewEncoder(w).Encode(response)
dcontext.GetResponseLogger(ctx).Info("get token complete")
}
type postTokenResponse struct {
Token string `json:"access_token"`
Scope string `json:"scope,omitempty"`
ExpiresIn int `json:"expires_in,omitempty"`
IssuedAt string `json:"issued_at,omitempty"`
RefreshToken string `json:"refresh_token,omitempty"`
}
// postToken handles authenticating the request and authorizing access to the
// requested scopes.
func (ts *tokenServer) postToken(ctx context.Context, w http.ResponseWriter, r *http.Request) {
grantType := r.PostFormValue("grant_type")
if grantType == "" {
handleError(ctx, ErrorMissingRequiredField.WithDetail("missing grant_type value"), w)
return
}
service := r.PostFormValue("service")
if service == "" {
handleError(ctx, ErrorMissingRequiredField.WithDetail("missing service value"), w)
return
}
clientID := r.PostFormValue("client_id")
if clientID == "" {
handleError(ctx, ErrorMissingRequiredField.WithDetail("missing client_id value"), w)
return
}
var offline bool
switch r.PostFormValue("access_type") {
case "", "online":
case "offline":
offline = true
default:
handleError(ctx, ErrorUnsupportedValue.WithDetail("unknown access_type value"), w)
return
}
requestedAccessList := ResolveScopeList(ctx, r.PostFormValue("scope"))
var subject string
var rToken string
switch grantType {
case "refresh_token":
rToken = r.PostFormValue("refresh_token")
if rToken == "" {
handleError(ctx, ErrorUnsupportedValue.WithDetail("missing refresh_token value"), w)
return
}
rt, ok := ts.refreshCache[rToken]
if !ok || rt.service != service {
handleError(ctx, errcode.ErrorCodeUnauthorized.WithDetail("invalid refresh token"), w)
return
}
subject = rt.subject
case "password":
ca, ok := ts.accessController.(auth.CredentialAuthenticator)
if !ok {
handleError(ctx, ErrorUnsupportedValue.WithDetail("password grant type not supported"), w)
return
}
subject = r.PostFormValue("username")
if subject == "" {
handleError(ctx, ErrorUnsupportedValue.WithDetail("missing username value"), w)
return
}
password := r.PostFormValue("password")
if password == "" {
handleError(ctx, ErrorUnsupportedValue.WithDetail("missing password value"), w)
return
}
if err := ca.AuthenticateUser(subject, password); err != nil {
handleError(ctx, errcode.ErrorCodeUnauthorized.WithDetail("invalid credentials"), w)
return
}
default:
handleError(ctx, ErrorUnsupportedValue.WithDetail("unknown grant_type value"), w)
return
}
ctx = context.WithValue(ctx, acctSubject{}, subject)
ctx = dcontext.WithLogger(ctx, dcontext.GetLogger(ctx, acctSubject{}))
dcontext.GetLogger(ctx).Info("authenticated client")
ctx = context.WithValue(ctx, requestedAccess{}, requestedAccessList)
ctx = dcontext.WithLogger(ctx, dcontext.GetLogger(ctx, requestedAccess{}))
grantedAccessList := filterAccessList(ctx, subject, requestedAccessList)
ctx = context.WithValue(ctx, grantedAccess{}, grantedAccessList)
ctx = dcontext.WithLogger(ctx, dcontext.GetLogger(ctx, grantedAccess{}))
token, err := ts.issuer.CreateJWT(subject, service, grantedAccessList)
if err != nil {
handleError(ctx, err, w)
return
}
dcontext.GetLogger(ctx).Info("authorized client")
response := postTokenResponse{
Token: token,
ExpiresIn: int(ts.issuer.Expiration.Seconds()),
IssuedAt: time.Now().UTC().Format(time.RFC3339),
Scope: ToScopeList(grantedAccessList),
}
if offline {
rToken = newRefreshToken()
ts.refreshCache[rToken] = refreshToken{
subject: subject,
service: service,
}
}
if rToken != "" {
response.RefreshToken = rToken
}
ctx, w = dcontext.WithResponseWriter(ctx, w)
w.Header().Set("Content-Type", "application/json")
json.NewEncoder(w).Encode(response)
dcontext.GetResponseLogger(ctx).Info("post token complete")
}