seaweedfs/weed/s3api/auth_credentials.go

package s3api

import (
	"bytes"
	"fmt"
	"io/ioutil"
	"net/http"

	"github.com/golang/protobuf/jsonpb"

	"github.com/chrislusf/seaweedfs/weed/glog"
	"github.com/chrislusf/seaweedfs/weed/pb/iam_pb"
)

type Action string

const (
	ACTION_READ  = "Read"
	ACTION_WRITE = "Write"
	ACTION_ADMIN = "Admin"
)

type Iam interface {
	Check(f http.HandlerFunc, actions ...Action) http.HandlerFunc
}

type IdentityAccessManagement struct {
	identities []*Identity
}

type Identity struct {
	Name        string
	Credentials []*Credential
	Actions     []Action
}

type Credential struct {
	AccessKey string
	SecretKey string
}

func NewIdentityAccessManagement(fileName string) *IdentityAccessManagement {
	iam := &IdentityAccessManagement{}
	if fileName == "" {
		return iam
	}
	if err := iam.loadIdentities(fileName); err != nil {
		glog.Fatalf("fail to load config file %s: %v", fileName, err)
	}
	return iam
}

func (iam *IdentityAccessManagement) loadIdentities(fileName string) error {

	identities := &iam_pb.Identities{}

	rawData, readErr := ioutil.ReadFile(fileName)
	if readErr != nil {
		glog.Warningf("fail to read %s : %v", fileName, readErr)
		return fmt.Errorf("fail to read %s : %v", fileName, readErr)
	}

	glog.V(1).Infof("maybeLoadVolumeInfo Unmarshal volume info %v", fileName)
	if err := jsonpb.Unmarshal(bytes.NewReader(rawData), identities); err != nil {
		glog.Warningf("unmarshal error: %v", err)
		return fmt.Errorf("unmarshal %s error: %v", fileName, err)
	}

	for _, ident := range identities.Identities {
		t := &Identity{
			Name:        ident.Name,
			Credentials: nil,
			Actions:     nil,
		}
		for _, action := range ident.Actions {
			t.Actions = append(t.Actions, Action(action))
		}
		for _, cred := range ident.Credentials {
			t.Credentials = append(t.Credentials, &Credential{
				AccessKey: cred.AccessKey,
				SecretKey: cred.SecretKey,
			})
		}
		iam.identities = append(iam.identities, t)
	}

	return nil
}

func (iam *IdentityAccessManagement) lookupByAccessKey(accessKey string) (identity *Identity, cred *Credential, found bool) {
	for _, ident := range iam.identities {
		for _, cred := range ident.Credentials {
			if cred.AccessKey == accessKey {
				return ident, cred, true
			}
		}
	}
	return nil, nil, false
}

func (iam *IdentityAccessManagement) Auth(f http.HandlerFunc, actions ...Action) http.HandlerFunc {

	if len(iam.identities) == 0 {
		return f
	}

	return func(w http.ResponseWriter, r *http.Request) {
		errCode := iam.authRequest(r, actions)
		if errCode == ErrNone {
			f(w, r)
			return
		}
		writeErrorResponse(w, errCode, r.URL)
	}
}

// check whether the request has valid access keys
func (iam *IdentityAccessManagement) authRequest(r *http.Request, actions []Action) ErrorCode {
	var identity *Identity
	var s3Err ErrorCode
	switch getRequestAuthType(r) {
	case authTypeUnknown, authTypeStreamingSigned:
		return ErrAccessDenied
	case authTypePresignedV2, authTypeSignedV2:
		return ErrNotImplemented
	case authTypeSigned, authTypePresigned:
		identity, s3Err = iam.reqSignatureV4Verify(r)
		if s3Err != ErrNone {
			return s3Err
		}
	}

	if !identity.canDo(actions) {
		return ErrAccessDenied
	}

	return ErrNone

}

func (identity *Identity) canDo(actions []Action) bool {
	for _, a := range identity.Actions {
		for _, b := range actions {
			if a == b {
				return true
			}
		}
	}
	return false
}