distribution/auth/auth.go

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package auth
import (
"fmt"
"net/http"
)
// Resource describes a resource by type and name.
type Resource struct {
Type string
Name string
}
// Access describes a specific action that is
// requested or allowed for a given recource.
type Access struct {
Resource
Action string
}
// Challenge is a special error type which is used for HTTP 401 Unauthorized
// responses and is able to write the response with WWW-Authenticate challenge
// header values based on the error.
type Challenge interface {
error
Status() int
SetHeader(header http.Header)
ServeHTTP(w http.ResponseWriter, r *http.Request)
}
// AccessController controls access to registry resources based on a request
// and required access levels for a request. Implementations can support both
// complete denial and http authorization challenges.
type AccessController interface {
// Authorized returns non-nil if the request is granted the request
// access. If the error is non-nil, access should always be denied. The
// error may be of type Challenge, in which case the caller may have the
// Challenge handle the request or choose what action to take based on the
// Challenge header or response status.
//
// In the future, other error types, besides Challenge, may be added to
// support more complex authorization flows.
Authorized(req *http.Request, access ...Access) error
}
// InitFunc is the type of an AccessController factory function and is used
// to register the contsructor for different AccesController backends.
type InitFunc func(options map[string]interface{}) (AccessController, error)
var accessControllers map[string]InitFunc
func init() {
accessControllers = make(map[string]InitFunc)
}
// Register is used to register an InitFunc for
// an AccessController backend with the given name.
func Register(name string, initFunc InitFunc) error {
if _, exists := accessControllers[name]; exists {
return fmt.Errorf("name already registered: %s", name)
}
accessControllers[name] = initFunc
return nil
}
// GetAccessController constructs an AccessController
// with the given options using the named backend.
func GetAccessController(name string, options map[string]interface{}) (AccessController, error) {
if initFunc, exists := accessControllers[name]; exists {
return initFunc(options)
}
return nil, fmt.Errorf("no access controller registered with name: %s", name)
}