signature: No need to validate region for getBucketLocation and listBuckets.

This type of check is added for making sure that we can support
custom regions.

ListBuckets and GetBucketLocation are always "us-east-1" rest
should look for the configured region.

Fixes #1278

auth-handler.go

@@ -129,10 +129,11 @@ func isReqAuthenticated(r *http.Request) (s3Error APIErrorCode) {
 	}
 	// Populate back the payload.
 	r.Body = ioutil.NopCloser(bytes.NewReader(payload))
+	validateRegion := true // Validate region.
 	if isRequestSignatureV4(r) {
-		return doesSignatureMatch(hex.EncodeToString(sum256(payload)), r)
+		return doesSignatureMatch(hex.EncodeToString(sum256(payload)), r, validateRegion)
 	} else if isRequestPresignedSignatureV4(r) {
-		return doesPresignedSignatureMatch(r)
+		return doesPresignedSignatureMatch(r, validateRegion)
 	}
 	return ErrAccessDenied
 }

bucket-handlers.go

@@ -18,6 +18,8 @@ package main
 
 import (
 	"bytes"
+	"encoding/base64"
+	"encoding/hex"
 	"encoding/xml"
 	"io"
 	"io/ioutil"
@@ -88,7 +90,28 @@ func (api objectStorageAPI) GetBucketLocationHandler(w http.ResponseWriter, r *h
 			return
 		}
 	case authTypeSigned, authTypePresigned:
-		if s3Error := isReqAuthenticated(r); s3Error != ErrNone {
+		payload, e := ioutil.ReadAll(r.Body)
+		if e != nil {
+			writeErrorResponse(w, r, ErrInternalError, r.URL.Path)
+			return
+		}
+		// Verify Content-Md5, if payload is set.
+		if r.Header.Get("Content-Md5") != "" {
+			if r.Header.Get("Content-Md5") != base64.StdEncoding.EncodeToString(sumMD5(payload)) {
+				writeErrorResponse(w, r, ErrBadDigest, r.URL.Path)
+				return
+			}
+		}
+		// Populate back the payload.
+		r.Body = ioutil.NopCloser(bytes.NewReader(payload))
+		var s3Error APIErrorCode // API error code.
+		validateRegion := false  // Validate region.
+		if isRequestSignatureV4(r) {
+			s3Error = doesSignatureMatch(hex.EncodeToString(sum256(payload)), r, validateRegion)
+		} else if isRequestPresignedSignatureV4(r) {
+			s3Error = doesPresignedSignatureMatch(r, validateRegion)
+		}
+		if s3Error != ErrNone {
 			writeErrorResponse(w, r, s3Error, r.URL.Path)
 			return
 		}
@@ -117,7 +140,7 @@ func (api objectStorageAPI) GetBucketLocationHandler(w http.ResponseWriter, r *h
 			Location: region,
 		})
 	}
-	setCommonHeaders(w) // write headers.
+	setCommonHeaders(w) // Write headers.
 	writeSuccessResponse(w, encodedSuccessResponse)
 }
 
@@ -256,7 +279,28 @@ func (api objectStorageAPI) ListBucketsHandler(w http.ResponseWriter, r *http.Re
 		writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
 		return
 	case authTypeSigned, authTypePresigned:
-		if s3Error := isReqAuthenticated(r); s3Error != ErrNone {
+		payload, e := ioutil.ReadAll(r.Body)
+		if e != nil {
+			writeErrorResponse(w, r, ErrInternalError, r.URL.Path)
+			return
+		}
+		// Verify Content-Md5, if payload is set.
+		if r.Header.Get("Content-Md5") != "" {
+			if r.Header.Get("Content-Md5") != base64.StdEncoding.EncodeToString(sumMD5(payload)) {
+				writeErrorResponse(w, r, ErrBadDigest, r.URL.Path)
+				return
+			}
+		}
+		// Populate back the payload.
+		r.Body = ioutil.NopCloser(bytes.NewReader(payload))
+		var s3Error APIErrorCode // API error code.
+		validateRegion := false  // Validate region.
+		if isRequestSignatureV4(r) {
+			s3Error = doesSignatureMatch(hex.EncodeToString(sum256(payload)), r, validateRegion)
+		} else if isRequestPresignedSignatureV4(r) {
+			s3Error = doesPresignedSignatureMatch(r, validateRegion)
+		}
+		if s3Error != ErrNone {
 			writeErrorResponse(w, r, s3Error, r.URL.Path)
 			return
 		}

object-handlers.go

@@ -601,8 +601,9 @@ func (api objectStorageAPI) PutObjectHandler(w http.ResponseWriter, r *http.Requ
 		// Create anonymous object.
 		objectInfo, err = api.ObjectAPI.PutObject(bucket, object, size, r.Body, nil)
 	case authTypePresigned:
+		validateRegion := true // Validate region.
 		// For presigned requests verify them right here.
-		if apiErr := doesPresignedSignatureMatch(r); apiErr != ErrNone {
+		if apiErr := doesPresignedSignatureMatch(r, validateRegion); apiErr != ErrNone {
 			writeErrorResponse(w, r, apiErr, r.URL.Path)
 			return
 		}
@@ -622,7 +623,8 @@ func (api objectStorageAPI) PutObjectHandler(w http.ResponseWriter, r *http.Requ
 				return
 			}
 			shaPayload := shaWriter.Sum(nil)
-			if apiErr := doesSignatureMatch(hex.EncodeToString(shaPayload), r); apiErr != ErrNone {
+			validateRegion := true // Validate region.
+			if apiErr := doesSignatureMatch(hex.EncodeToString(shaPayload), r, validateRegion); apiErr != ErrNone {
 				if apiErr == ErrSignatureDoesNotMatch {
 					writer.CloseWithError(errSignatureMismatch)
 					return
@@ -779,8 +781,9 @@ func (api objectStorageAPI) PutObjectPartHandler(w http.ResponseWriter, r *http.
 		// already allowed.
 		partMD5, err = api.ObjectAPI.PutObjectPart(bucket, object, uploadID, partID, size, r.Body, hex.EncodeToString(md5Bytes))
 	case authTypePresigned:
+		validateRegion := true // Validate region.
 		// For presigned requests verify right here.
-		apiErr := doesPresignedSignatureMatch(r)
+		apiErr := doesPresignedSignatureMatch(r, validateRegion)
 		if apiErr != ErrNone {
 			writeErrorResponse(w, r, apiErr, r.URL.Path)
 			return
@@ -800,7 +803,8 @@ func (api objectStorageAPI) PutObjectPartHandler(w http.ResponseWriter, r *http.
 				return
 			}
 			shaPayload := shaWriter.Sum(nil)
-			if apiErr := doesSignatureMatch(hex.EncodeToString(shaPayload), r); apiErr != ErrNone {
+			validateRegion := true // Validate region.
+			if apiErr := doesSignatureMatch(hex.EncodeToString(shaPayload), r, validateRegion); apiErr != ErrNone {
 				if apiErr == ErrSignatureDoesNotMatch {
 					writer.CloseWithError(errSignatureMismatch)
 					return

signature-v4.go

@@ -195,7 +195,8 @@ func doesPolicySignatureMatch(formValues map[string]string) APIErrorCode {
 	}
 
 	// Verify if the region is valid.
-	if !isValidRegion(credHeader.scope.region, region) {
+	sRegion := credHeader.scope.region
+	if !isValidRegion(sRegion, region) {
 		return ErrInvalidRegion
 	}
 
@@ -221,7 +222,7 @@ func doesPolicySignatureMatch(formValues map[string]string) APIErrorCode {
 // doesPresignedSignatureMatch - Verify query headers with presigned signature
 //     - http://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-query-string-auth.html
 // returns true if matches, false otherwise. if error is not nil then it is always false
-func doesPresignedSignatureMatch(r *http.Request) APIErrorCode {
+func doesPresignedSignatureMatch(r *http.Request, validateRegion bool) APIErrorCode {
 	// Access credentials.
 	cred := serverConfig.GetCredential()
 
@@ -244,9 +245,15 @@ func doesPresignedSignatureMatch(r *http.Request) APIErrorCode {
 
 	// Verify if region is valid.
 	sRegion := preSignValues.Credential.scope.region
+	// Should validate region, only if region is set. Some operations
+	// do not need region validated for example GetBucketLocation.
+	if validateRegion {
 		if !isValidRegion(sRegion, region) {
 			return ErrInvalidRegion
 		}
+	} else {
+		region = sRegion
+	}
 
 	// Extract all the signed headers along with its values.
 	extractedSignedHeaders := extractSignedHeaders(preSignValues.SignedHeaders, req.Header)
@@ -267,7 +274,7 @@ func doesPresignedSignatureMatch(r *http.Request) APIErrorCode {
 	query.Set("X-Amz-Date", t.Format(iso8601Format))
 	query.Set("X-Amz-Expires", strconv.Itoa(expireSeconds))
 	query.Set("X-Amz-SignedHeaders", getSignedHeaders(extractedSignedHeaders))
-	query.Set("X-Amz-Credential", cred.AccessKeyID+"/"+getScope(t, region))
+	query.Set("X-Amz-Credential", cred.AccessKeyID+"/"+getScope(t, sRegion))
 
 	// Save other headers available in the request parameters.
 	for k, v := range req.URL.Query() {
@@ -321,7 +328,7 @@ func doesPresignedSignatureMatch(r *http.Request) APIErrorCode {
 // doesSignatureMatch - Verify authorization header with calculated header in accordance with
 //     - http://docs.aws.amazon.com/AmazonS3/latest/API/sig-v4-authenticating-requests.html
 // returns true if matches, false otherwise. if error is not nil then it is always false
-func doesSignatureMatch(hashedPayload string, r *http.Request) APIErrorCode {
+func doesSignatureMatch(hashedPayload string, r *http.Request, validateRegion bool) APIErrorCode {
 	// Access credentials.
 	cred := serverConfig.GetCredential()
 
@@ -350,9 +357,15 @@ func doesSignatureMatch(hashedPayload string, r *http.Request) APIErrorCode {
 
 	// Verify if region is valid.
 	sRegion := signV4Values.Credential.scope.region
+	// Should validate region, only if region is set. Some operations
+	// do not need region validated for example GetBucketLocation.
+	if validateRegion {
 		if !isValidRegion(sRegion, region) {
 			return ErrInvalidRegion
 		}
+	} else {
+		region = sRegion
+	}
 
 	// Extract date, if not present throw error.
 	var date string