s3cmd: Handle support for s3cmd.

README.md

@@ -126,11 +126,28 @@ Listening on http://172.30.2.17:9000
 Please follow the documentation here - [Using aws-sdk-go with Minio server](./AWS-SDK-GO.md)
 
 #### How to use s3cmd with Minio?
-<blockquote>
-Even with Signature version '4' enabled, 's3cmd' falls back to Signature version '2' for listing your buckets. Since minio server is only Signature version '4' listing your buckets with Signature version '2' fails. We have no immediate plans on supporting Signature version '2'. Please follow https://github.com/minio/minio/issues/987 to know more on this issue.
-</blockquote>
 
-`s3cmd` is currently not supported.
+Edit the following fields in your s3cmd configuration file. ~/.s3cfg
+
+```
+host_base = localhost:9000
+host_bucket = localhost:9000
+access_key = YOUR_ACCESS_KEY_HERE
+secret_key = YOUR_SECRET_KEY_HERE
+```
+
+To list your buckets.
+```
+$ s3cmd --region us-east-1 ls s3://
+2015-12-09 16:12  s3://testbbucket
+```
+
+To list contents inside buckets.
+```
+$ s3cmd --region us-east-1 ls s3://testbucket/
+                       DIR   s3://testbucket/test/
+2015-12-09 16:05    138504   s3://testbucket/newfile
+```
 
 ## Contribute to Minio Project
 Please follow Minio [Contributor's Guide](./CONTRIBUTING.md)

api-errors.go

@@ -33,6 +33,8 @@ type APIErrorResponse struct {
 	XMLName    xml.Name `xml:"Error" json:"-"`
 	Code       string
 	Message    string
+	Key        string
+	BucketName string
 	Resource   string
 	RequestID  string `xml:"RequestId"`
 	HostID     string `xml:"HostId"`
@@ -70,6 +72,7 @@ const (
 	InvalidPartOrder
 	AuthorizationHeaderMalformed
 	MalformedPOSTRequest
+	SignatureVersionNotSupported
 	BucketNotEmpty
 	RootPathFull
 )
@@ -221,6 +224,11 @@ var errorCodeResponse = map[int]APIError{
 		Description:    "The body of your POST request is not well-formed multipart/form-data.",
 		HTTPStatusCode: http.StatusBadRequest,
 	},
+	SignatureVersionNotSupported: {
+		Code:           "InvalidRequest",
+		Description:    "The authorization mechanism you have provided is not supported. Please use AWS4-HMAC-SHA256.",
+		HTTPStatusCode: http.StatusBadRequest,
+	},
 	BucketNotEmpty: {
 		Code:           "BucketNotEmpty",
 		Description:    "The bucket you tried to delete is not empty.",

api-headers.go

@@ -57,6 +57,7 @@ func setCommonHeaders(w http.ResponseWriter, contentLength int) {
 func encodeErrorResponse(response interface{}) []byte {
 	var bytesBuffer bytes.Buffer
 	// write common headers
+	bytesBuffer.WriteString(xml.Header)
 	e := xml.NewEncoder(&bytesBuffer)
 	e.Encode(response)
 	return bytesBuffer.Bytes()
@@ -92,6 +93,7 @@ func setObjectHeaders(w http.ResponseWriter, metadata fs.ObjectMetadata, content
 
 func encodeSuccessResponse(response interface{}) []byte {
 	var bytesBuffer bytes.Buffer
+	bytesBuffer.WriteString(xml.Header)
 	e := xml.NewEncoder(&bytesBuffer)
 	e.Encode(response)
 	return bytesBuffer.Bytes()

generic-handlers.go

@@ -46,6 +46,10 @@ type resourceHandler struct {
 	handler http.Handler
 }
 
+type ignoreSignatureV2RequestHandler struct {
+	handler http.Handler
+}
+
 func parseDate(req *http.Request) (time.Time, error) {
 	amzDate := req.Header.Get(http.CanonicalHeaderKey("x-amz-date"))
 	switch {
@@ -128,6 +132,23 @@ func CorsHandler(h http.Handler) http.Handler {
 	return c.Handler(h)
 }
 
+// IgnoreSignatureV2RequestHandler -
+// Verify if authorization header has signature version '2', reject it cleanly.
+func IgnoreSignatureV2RequestHandler(h http.Handler) http.Handler {
+	return ignoreSignatureV2RequestHandler{h}
+}
+
+// Ignore signature version '2' ServerHTTP() wrapper.
+func (h ignoreSignatureV2RequestHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if _, ok := r.Header["Authorization"]; ok {
+		if !strings.HasPrefix(r.Header.Get("Authorization"), authHeaderPrefix) {
+			writeErrorResponse(w, r, SignatureVersionNotSupported, r.URL.Path)
+			return
+		}
+	}
+	h.handler.ServeHTTP(w, r)
+}
+
 // IgnoreResourcesHandler -
 // Ignore resources handler is wrapper handler used for API request resource validation
 // Since we do not support all the S3 queries, it is necessary for us to throw back a

routers.go

@@ -80,9 +80,10 @@ func getNewCloudStorageAPI(conf cloudServerConfig) CloudStorageAPI {
 
 func getCloudStorageAPIHandler(api CloudStorageAPI) http.Handler {
 	var mwHandlers = []MiddlewareHandler{
+		CorsHandler,
 		TimeValidityHandler,
 		IgnoreResourcesHandler,
-		CorsHandler,
+		IgnoreSignatureV2RequestHandler,
 	}
 	if !api.Anonymous {
 		mwHandlers = append(mwHandlers, SignatureHandler)

signature-handler.go

@@ -37,8 +37,10 @@ func SignatureHandler(h http.Handler) http.Handler {
 
 func isRequestSignatureV4(req *http.Request) bool {
 	if _, ok := req.Header["Authorization"]; ok {
+		if strings.HasPrefix(req.Header.Get("Authorization"), authHeaderPrefix) {
 			return ok
 		}
+	}
 	return false
 }