s3cmd: Fix signature issues related to s3cmd.

Support regions both 'us-east-1' and 'US' (short hand for US Standard)
honored by S3.

README.md

@@ -138,13 +138,13 @@ secret_key = YOUR_SECRET_KEY_HERE
 
 To list your buckets.
 ```
-$ s3cmd --region us-east-1 ls s3://
+$ s3cmd ls s3://
 2015-12-09 16:12  s3://testbbucket
 ```
 
 To list contents inside buckets.
 ```
-$ s3cmd --region us-east-1 ls s3://testbucket/
+$ s3cmd ls s3://testbucket/
                        DIR   s3://testbucket/test/
 2015-12-09 16:05    138504   s3://testbucket/newfile
 ```

api-signature.go

@@ -57,12 +57,6 @@ func getCredentialsFromAuth(authValue string) ([]string, *probe.Error) {
 	if len(credentials) != 2 {
 		return nil, probe.NewError(errMissingFieldsCredentialTag)
 	}
-	if len(strings.Split(strings.TrimSpace(authFields[1]), "=")) != 2 {
-		return nil, probe.NewError(errMissingFieldsSignedHeadersTag)
-	}
-	if len(strings.Split(strings.TrimSpace(authFields[2]), "=")) != 2 {
-		return nil, probe.NewError(errMissingFieldsSignatureTag)
-	}
 	credentialElements := strings.Split(strings.TrimSpace(credentials[1]), "/")
 	if len(credentialElements) != 5 {
 		return nil, probe.NewError(errCredentialTagMalformed)
@@ -70,24 +64,55 @@ func getCredentialsFromAuth(authValue string) ([]string, *probe.Error) {
 	return credentialElements, nil
 }
 
-// verify if authHeader value has valid region
+func getSignatureFromAuth(authHeaderValue string) (string, *probe.Error) {
-func isValidRegion(authHeaderValue string) *probe.Error {
+	authValue := strings.TrimPrefix(authHeaderValue, authHeaderPrefix)
-	credentialElements, err := getCredentialsFromAuth(authHeaderValue)
+	authFields := strings.Split(strings.TrimSpace(authValue), ",")
-	if err != nil {
+	if len(authFields) != 3 {
-		return err.Trace()
+		return "", probe.NewError(errInvalidAuthHeaderValue)
 	}
-	region := credentialElements[2]
+	if len(strings.Split(strings.TrimSpace(authFields[2]), "=")) != 2 {
-	if region != "us-east-1" {
+		return "", probe.NewError(errMissingFieldsSignatureTag)
+	}
+	signature := strings.Split(strings.TrimSpace(authFields[2]), "=")[1]
+	return signature, nil
+}
+
+func getSignedHeadersFromAuth(authHeaderValue string) ([]string, *probe.Error) {
+	authValue := strings.TrimPrefix(authHeaderValue, authHeaderPrefix)
+	authFields := strings.Split(strings.TrimSpace(authValue), ",")
+	if len(authFields) != 3 {
+		return nil, probe.NewError(errInvalidAuthHeaderValue)
+	}
+	if len(strings.Split(strings.TrimSpace(authFields[1]), "=")) != 2 {
+		return nil, probe.NewError(errMissingFieldsSignedHeadersTag)
+	}
+	signedHeaders := strings.Split(strings.Split(strings.TrimSpace(authFields[1]), "=")[1], ";")
+	return signedHeaders, nil
+}
+
+// verify if region value is valid.
+func isValidRegion(region string) *probe.Error {
+	if region != "us-east-1" && region != "US" {
 		return probe.NewError(errInvalidRegion)
 	}
 	return nil
 }
 
-// stripAccessKeyID - strip only access key id from auth header
+// stripRegion - strip only region from auth header.
-func stripAccessKeyID(authHeaderValue string) (string, *probe.Error) {
+func stripRegion(authHeaderValue string) (string, *probe.Error) {
-	if err := isValidRegion(authHeaderValue); err != nil {
+	credentialElements, err := getCredentialsFromAuth(authHeaderValue)
-		return "", err.Trace()
+	if err != nil {
+		return "", err.Trace(authHeaderValue)
 	}
+	region := credentialElements[2]
+	if err = isValidRegion(region); err != nil {
+		return "", err.Trace(authHeaderValue)
+	}
+	return region, nil
+}
+
+// stripAccessKeyID - strip only access key id from auth header.
+func stripAccessKeyID(authHeaderValue string) (string, *probe.Error) {
 	credentialElements, err := getCredentialsFromAuth(authHeaderValue)
 	if err != nil {
 		return "", err.Trace()
@@ -99,25 +124,36 @@ func stripAccessKeyID(authHeaderValue string) (string, *probe.Error) {
 	return accessKeyID, nil
 }
 
-// initSignatureV4 initializing signature verification
+// initSignatureV4 initializing signature verification.
 func initSignatureV4(req *http.Request) (*fs.Signature, *probe.Error) {
-	// strip auth from authorization header
+	// strip auth from authorization header.
 	authHeaderValue := req.Header.Get("Authorization")
+
+	region, err := stripRegion(authHeaderValue)
+	if err != nil {
+		return nil, err.Trace(authHeaderValue)
+	}
 	accessKeyID, err := stripAccessKeyID(authHeaderValue)
 	if err != nil {
-		return nil, err.Trace()
+		return nil, err.Trace(authHeaderValue)
+	}
+	signature, err := getSignatureFromAuth(authHeaderValue)
+	if err != nil {
+		return nil, err.Trace(authHeaderValue)
+	}
+	signedHeaders, err := getSignedHeadersFromAuth(authHeaderValue)
+	if err != nil {
+		return nil, err.Trace(authHeaderValue)
 	}
 	config, err := loadConfigV2()
 	if err != nil {
 		return nil, err.Trace()
 	}
-	authFields := strings.Split(strings.TrimSpace(authHeaderValue), ",")
-	signedHeaders := strings.Split(strings.Split(strings.TrimSpace(authFields[1]), "=")[1], ";")
-	signature := strings.Split(strings.TrimSpace(authFields[2]), "=")[1]
 	if config.Credentials.AccessKeyID == accessKeyID {
 		signature := &fs.Signature{
 			AccessKeyID:     config.Credentials.AccessKeyID,
 			SecretAccessKey: config.Credentials.SecretAccessKey,
+			Region:          region,
 			Signature:       signature,
 			SignedHeaders:   signedHeaders,
 			Request:         req,
@@ -216,10 +252,12 @@ func initPostPresignedPolicyV4(formValues map[string]string) (*fs.Signature, *pr
 	if perr != nil {
 		return nil, perr.Trace()
 	}
+	region := credentialElements[2]
 	if config.Credentials.AccessKeyID == accessKeyID {
 		signature := &fs.Signature{
 			AccessKeyID:     config.Credentials.AccessKeyID,
 			SecretAccessKey: config.Credentials.SecretAccessKey,
+			Region:          region,
 			Signature:       formValues["X-Amz-Signature"],
 			PresignedPolicy: formValues["Policy"],
 		}
@@ -242,12 +280,14 @@ func initPresignedSignatureV4(req *http.Request) (*fs.Signature, *probe.Error) {
 	if err != nil {
 		return nil, err.Trace()
 	}
+	region := credentialElements[2]
 	signedHeaders := strings.Split(strings.TrimSpace(req.URL.Query().Get("X-Amz-SignedHeaders")), ";")
 	signature := strings.TrimSpace(req.URL.Query().Get("X-Amz-Signature"))
 	if config.Credentials.AccessKeyID == accessKeyID {
 		signature := &fs.Signature{
 			AccessKeyID:     config.Credentials.AccessKeyID,
 			SecretAccessKey: config.Credentials.SecretAccessKey,
+			Region:          region,
 			Signature:       signature,
 			SignedHeaders:   signedHeaders,
 			Presigned:       true,

pkg/fs/fs-bucket-listobjects.go

@@ -100,10 +100,19 @@ func (fs Filesystem) ListObjects(bucket string, resources BucketResourcesMetadat
 				FileInfo: fl,
 			})
 		} else {
-			files, err := ioutil.ReadDir(filepath.Join(rootPrefix, resources.Prefix))
+			var prefixPath string
+			if runtime.GOOS == "windows" {
+				prefixPath = rootPrefix + string(os.PathSeparator) + resources.Prefix
+			} else {
+				prefixPath = rootPrefix + string(os.PathSeparator) + resources.Prefix
+			}
+			files, err := ioutil.ReadDir(prefixPath)
 			if err != nil {
-				if os.IsNotExist(err) {
+				switch err := err.(type) {
-					return nil, resources, probe.NewError(ObjectNotFound{Bucket: bucket, Object: resources.Prefix})
+				case *os.PathError:
+					if err.Op == "open" {
+						return nil, resources, probe.NewError(ObjectNotFound{Bucket: bucket, Object: resources.Prefix})
+					}
 				}
 				return nil, resources, probe.NewError(err)
 			}

pkg/fs/signature.go

@@ -37,6 +37,7 @@ import (
 type Signature struct {
 	AccessKeyID     string
 	SecretAccessKey string
+	Region          string
 	Presigned       bool
 	PresignedPolicy string
 	SignedHeaders   []string
@@ -210,7 +211,7 @@ func (r Signature) getPresignedCanonicalRequest(presignedQuery string) string {
 func (r Signature) getScope(t time.Time) string {
 	scope := strings.Join([]string{
 		t.Format(yyyymmdd),
-		"us-east-1",
+		r.Region,
 		"s3",
 		"aws4_request",
 	}, "/")
@@ -229,7 +230,7 @@ func (r Signature) getStringToSign(canonicalRequest string, t time.Time) string
 func (r Signature) getSigningKey(t time.Time) []byte {
 	secret := r.SecretAccessKey
 	date := sumHMAC([]byte("AWS4"+secret), []byte(t.Format(yyyymmdd)))
-	region := sumHMAC(date, []byte("us-east-1"))
+	region := sumHMAC(date, []byte(r.Region))
 	service := sumHMAC(region, []byte("s3"))
 	signingKey := sumHMAC(service, []byte("aws4_request"))
 	return signingKey