diff --git a/weed/iamapi/iamapi_server.go b/weed/iamapi/iamapi_server.go
index 7698fab71..d0a033ed6 100644
--- a/weed/iamapi/iamapi_server.go
+++ b/weed/iamapi/iamapi_server.go
@@ -9,6 +9,8 @@ import (
 	"github.com/chrislusf/seaweedfs/weed/pb"
 	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
 	"github.com/chrislusf/seaweedfs/weed/pb/iam_pb"
+	"github.com/chrislusf/seaweedfs/weed/s3api"
+	. "github.com/chrislusf/seaweedfs/weed/s3api/s3_constants"
 	"github.com/chrislusf/seaweedfs/weed/wdclient"
 	"github.com/gorilla/mux"
 	"google.golang.org/grpc"
@@ -36,7 +38,7 @@ type IamServerOption struct {
 
 type IamApiServer struct {
 	s3ApiConfig IamS3ApiConfig
-	filerclient *filer_pb.SeaweedFilerClient
+	iam         *s3api.IdentityAccessManagement
 }
 
 var s3ApiConfigure IamS3ApiConfig
@@ -46,9 +48,10 @@ func NewIamApiServer(router *mux.Router, option *IamServerOption) (iamApiServer
 		option:       option,
 		masterClient: wdclient.NewMasterClient(option.GrpcDialOption, pb.AdminShellClient, "", 0, "", strings.Split(option.Masters, ",")),
 	}
-
+	s3Option := s3api.S3ApiServerOption{Filer: option.Filer}
 	iamApiServer = &IamApiServer{
 		s3ApiConfig: s3ApiConfigure,
+		iam:         s3api.NewIdentityAccessManagement(&s3Option),
 	}
 
 	iamApiServer.registerRouter(router)
@@ -62,7 +65,8 @@ func (iama *IamApiServer) registerRouter(router *mux.Router) {
 	// ListBuckets
 
 	// apiRouter.Methods("GET").Path("/").HandlerFunc(track(s3a.iam.Auth(s3a.ListBucketsHandler, ACTION_ADMIN), "LIST"))
-	apiRouter.Path("/").Methods("POST").HandlerFunc(iama.DoActions)
+	apiRouter.Methods("POST").Path("/").HandlerFunc(iama.iam.Auth(iama.DoActions, ACTION_ADMIN))
+	//
 	// NotFound
 	apiRouter.NotFoundHandler = http.HandlerFunc(notFoundHandler)
 }
diff --git a/weed/s3api/auth_signature_v4.go b/weed/s3api/auth_signature_v4.go
index 5ef7439c8..0df26e6fc 100644
--- a/weed/s3api/auth_signature_v4.go
+++ b/weed/s3api/auth_signature_v4.go
@@ -24,6 +24,7 @@ import (
 	"crypto/subtle"
 	"encoding/hex"
 	"github.com/chrislusf/seaweedfs/weed/s3api/s3err"
+	"io/ioutil"
 	"net/http"
 	"net/url"
 	"regexp"
@@ -132,6 +133,17 @@ func (iam *IdentityAccessManagement) doesSignatureMatch(hashedPayload string, r
 	// Query string.
 	queryStr := req.URL.Query().Encode()
 
+	// Get hashed Payload
+	if signV4Values.Credential.scope.service != "s3" && hashedPayload == emptySHA256 && r.Body != nil {
+		buf, _ := ioutil.ReadAll(r.Body)
+		r.Body = ioutil.NopCloser(bytes.NewBuffer(buf))
+		b, _ := ioutil.ReadAll(bytes.NewBuffer(buf))
+		if len(b) != 0 {
+			bodyHash := sha256.Sum256(b)
+			hashedPayload = hex.EncodeToString(bodyHash[:])
+		}
+	}
+
 	// Get canonical request.
 	canonicalRequest := getCanonicalRequest(extractedSignedHeaders, hashedPayload, queryStr, req.URL.Path, req.Method)
 
@@ -139,7 +151,10 @@ func (iam *IdentityAccessManagement) doesSignatureMatch(hashedPayload string, r
 	stringToSign := getStringToSign(canonicalRequest, t, signV4Values.Credential.getScope())
 
 	// Get hmac signing key.
-	signingKey := getSigningKey(cred.SecretKey, signV4Values.Credential.scope.date, signV4Values.Credential.scope.region)
+	signingKey := getSigningKey(cred.SecretKey,
+		signV4Values.Credential.scope.date,
+		signV4Values.Credential.scope.region,
+		signV4Values.Credential.scope.service)
 
 	// Calculate signature.
 	newSignature := getSignature(signingKey, stringToSign)
@@ -310,7 +325,7 @@ func (iam *IdentityAccessManagement) doesPolicySignatureV4Match(formValues http.
 	}
 
 	// Get signing key.
-	signingKey := getSigningKey(cred.SecretKey, credHeader.scope.date, credHeader.scope.region)
+	signingKey := getSigningKey(cred.SecretKey, credHeader.scope.date, credHeader.scope.region, credHeader.scope.service)
 
 	// Get signature.
 	newSignature := getSignature(signingKey, formValues.Get("Policy"))
@@ -427,7 +442,10 @@ func (iam *IdentityAccessManagement) doesPresignedSignatureMatch(hashedPayload s
 	presignedStringToSign := getStringToSign(presignedCanonicalReq, t, pSignValues.Credential.getScope())
 
 	// Get hmac presigned signing key.
-	presignedSigningKey := getSigningKey(cred.SecretKey, pSignValues.Credential.scope.date, pSignValues.Credential.scope.region)
+	presignedSigningKey := getSigningKey(cred.SecretKey,
+		pSignValues.Credential.scope.date,
+		pSignValues.Credential.scope.region,
+		pSignValues.Credential.scope.service)
 
 	// Get new signature.
 	newSignature := getSignature(presignedSigningKey, presignedStringToSign)
@@ -655,11 +673,11 @@ func sumHMAC(key []byte, data []byte) []byte {
 }
 
 // getSigningKey hmac seed to calculate final signature.
-func getSigningKey(secretKey string, t time.Time, region string) []byte {
+func getSigningKey(secretKey string, t time.Time, region string, service string) []byte {
 	date := sumHMAC([]byte("AWS4"+secretKey), []byte(t.Format(yyyymmdd)))
 	regionBytes := sumHMAC(date, []byte(region))
-	service := sumHMAC(regionBytes, []byte("s3"))
-	signingKey := sumHMAC(service, []byte("aws4_request"))
+	serviceBytes := sumHMAC(regionBytes, []byte(service))
+	signingKey := sumHMAC(serviceBytes, []byte("aws4_request"))
 	return signingKey
 }
 
diff --git a/weed/s3api/auto_signature_v4_test.go b/weed/s3api/auto_signature_v4_test.go
index 4c8255768..b47cd5f2d 100644
--- a/weed/s3api/auto_signature_v4_test.go
+++ b/weed/s3api/auto_signature_v4_test.go
@@ -370,7 +370,7 @@ func preSignV4(req *http.Request, accessKeyID, secretAccessKey string, expires i
 	queryStr := strings.Replace(query.Encode(), "+", "%20", -1)
 	canonicalRequest := getCanonicalRequest(extractedSignedHeaders, unsignedPayload, queryStr, req.URL.Path, req.Method)
 	stringToSign := getStringToSign(canonicalRequest, date, scope)
-	signingKey := getSigningKey(secretAccessKey, date, region)
+	signingKey := getSigningKey(secretAccessKey, date, region, "s3")
 	signature := getSignature(signingKey, stringToSign)
 
 	req.URL.RawQuery = query.Encode()
diff --git a/weed/s3api/chunked_reader_v4.go b/weed/s3api/chunked_reader_v4.go
index 734c9faee..b163ec2f6 100644
--- a/weed/s3api/chunked_reader_v4.go
+++ b/weed/s3api/chunked_reader_v4.go
@@ -45,7 +45,7 @@ func getChunkSignature(secretKey string, seedSignature string, region string, da
 		hashedChunk
 
 	// Get hmac signing key.
-	signingKey := getSigningKey(secretKey, date, region)
+	signingKey := getSigningKey(secretKey, date, region, "s3")
 
 	// Calculate signature.
 	newSignature := getSignature(signingKey, stringToSign)
@@ -117,7 +117,7 @@ func (iam *IdentityAccessManagement) calculateSeedSignature(r *http.Request) (cr
 	stringToSign := getStringToSign(canonicalRequest, date, signV4Values.Credential.getScope())
 
 	// Get hmac signing key.
-	signingKey := getSigningKey(cred.SecretKey, signV4Values.Credential.scope.date, region)
+	signingKey := getSigningKey(cred.SecretKey, signV4Values.Credential.scope.date, region, "s3")
 
 	// Calculate signature.
 	newSignature := getSignature(signingKey, stringToSign)