add SCP support

SCP is an experimental feature, we have our own SCP implementation
since we can't rely on scp system command to proper handle permissions,
quota and user's home dir restrictions. The SCP protocol is quite simple
but there is no official docs about it, so we need more testing and
feedbacks before enabling it by default.
We may not handle some borderline cases or have sneaky bugs.

This commit contains some breaking changes to the REST API.
SFTPGo API should be stable now and I hope no more breaking changes
before the first stable release.

api/api.go

@@ -15,7 +15,7 @@ import (
 
 const (
 	logSender             = "api"
-	activeConnectionsPath = "/api/v1/sftp_connection"
+	activeConnectionsPath = "/api/v1/connection"
 	quotaScanPath         = "/api/v1/quota_scan"
 	userPath              = "/api/v1/user"
 	versionPath           = "/api/v1/version"

api/api_test.go

@@ -33,7 +33,7 @@ const (
 	testPubKey            = "ssh-rsa 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 nicola@p1"
 	logSender             = "APITesting"
 	userPath              = "/api/v1/user"
-	activeConnectionsPath = "/api/v1/sftp_connection"
+	activeConnectionsPath = "/api/v1/connection"
 	quotaScanPath         = "/api/v1/quota_scan"
 	versionPath           = "/api/v1/version"
 )
@@ -405,19 +405,19 @@ func TestGetVersion(t *testing.T) {
 	}
 }
 
-func TestGetSFTPConnections(t *testing.T) {
-	_, _, err := api.GetSFTPConnections(http.StatusOK)
+func TestGetConnections(t *testing.T) {
+	_, _, err := api.GetConnections(http.StatusOK)
 	if err != nil {
 		t.Errorf("unable to get sftp connections: %v", err)
 	}
-	_, _, err = api.GetSFTPConnections(http.StatusInternalServerError)
+	_, _, err = api.GetConnections(http.StatusInternalServerError)
 	if err == nil {
 		t.Errorf("get sftp connections request must succeed, we requested to check a wrong status code")
 	}
 }
 
-func TestCloseActiveSFTPConnection(t *testing.T) {
-	_, err := api.CloseSFTPConnection("non_existent_id", http.StatusNotFound)
+func TestCloseActiveConnection(t *testing.T) {
+	_, err := api.CloseConnection("non_existent_id", http.StatusNotFound)
 	if err != nil {
 		t.Errorf("unexpected error closing non existent sftp connection: %v", err)
 	}
@@ -686,7 +686,7 @@ func TestGetVersionMock(t *testing.T) {
 	checkResponseCode(t, http.StatusOK, rr.Code)
 }
 
-func TestGetSFTPConnectionsMock(t *testing.T) {
+func TestGetConnectionsMock(t *testing.T) {
 	req, _ := http.NewRequest(http.MethodGet, activeConnectionsPath, nil)
 	rr := executeRequest(req)
 	checkResponseCode(t, http.StatusOK, rr.Code)

api/api_utils.go

@@ -207,8 +207,8 @@ func StartQuotaScan(user dataprovider.User, expectedStatusCode int) ([]byte, err
 	return body, checkResponse(resp.StatusCode, expectedStatusCode)
 }
 
-// GetSFTPConnections returns status and stats for active SFTP connections
-func GetSFTPConnections(expectedStatusCode int) ([]sftpd.ConnectionStatus, []byte, error) {
+// GetConnections returns status and stats for active SFTP/SCP connections
+func GetConnections(expectedStatusCode int) ([]sftpd.ConnectionStatus, []byte, error) {
 	var connections []sftpd.ConnectionStatus
 	var body []byte
 	resp, err := getHTTPClient().Get(buildURLRelativeToBase(activeConnectionsPath))
@@ -225,8 +225,8 @@ func GetSFTPConnections(expectedStatusCode int) ([]sftpd.ConnectionStatus, []byt
 	return connections, body, err
 }
 
-// CloseSFTPConnection closes an active SFTP connection identified by connectionID
-func CloseSFTPConnection(connectionID string, expectedStatusCode int) ([]byte, error) {
+// CloseConnection closes an active  connection identified by connectionID
+func CloseConnection(connectionID string, expectedStatusCode int) ([]byte, error) {
 	var body []byte
 	req, err := http.NewRequest(http.MethodDelete, buildURLRelativeToBase(activeConnectionsPath, connectionID), nil)
 	if err != nil {

api/internal_test.go

@@ -161,7 +161,7 @@ func TestApiCallsWithBadURL(t *testing.T) {
 	if err == nil {
 		t.Errorf("request with invalid URL must fail")
 	}
-	_, err = CloseSFTPConnection("non_existent_id", http.StatusNotFound)
+	_, err = CloseConnection("non_existent_id", http.StatusNotFound)
 	if err == nil {
 		t.Errorf("request with invalid URL must fail")
 	}
@@ -200,11 +200,11 @@ func TestApiCallToNotListeningServer(t *testing.T) {
 	if err == nil {
 		t.Errorf("request to an inactive URL must fail")
 	}
-	_, _, err = GetSFTPConnections(http.StatusOK)
+	_, _, err = GetConnections(http.StatusOK)
 	if err == nil {
 		t.Errorf("request to an inactive URL must fail")
 	}
-	_, err = CloseSFTPConnection("non_existent_id", http.StatusNotFound)
+	_, err = CloseConnection("non_existent_id", http.StatusNotFound)
 	if err == nil {
 		t.Errorf("request to an inactive URL must fail")
 	}
@@ -215,13 +215,13 @@ func TestApiCallToNotListeningServer(t *testing.T) {
 	SetBaseURL(oldBaseURL)
 }
 
-func TestCloseSFTPConnectionHandler(t *testing.T) {
+func TestCloseConnectionHandler(t *testing.T) {
 	req, _ := http.NewRequest(http.MethodDelete, activeConnectionsPath+"/connectionID", nil)
 	rctx := chi.NewRouteContext()
 	rctx.URLParams.Add("connectionID", "")
 	req = req.WithContext(context.WithValue(req.Context(), chi.RouteCtxKey, rctx))
 	rr := httptest.NewRecorder()
-	handleCloseSFTPConnection(rr, req)
+	handleCloseConnection(rr, req)
 	if rr.Code != http.StatusBadRequest {
 		t.Errorf("Expected response code 400. Got %d", rr.Code)
 	}

api/router.go

@@ -40,7 +40,7 @@ func initializeRouter() {
 	})
 
 	router.Delete(activeConnectionsPath+"/{connectionID}", func(w http.ResponseWriter, r *http.Request) {
-		handleCloseSFTPConnection(w, r)
+		handleCloseConnection(w, r)
 	})
 
 	router.Get(quotaScanPath, func(w http.ResponseWriter, r *http.Request) {
@@ -72,7 +72,7 @@ func initializeRouter() {
 	})
 }
 
-func handleCloseSFTPConnection(w http.ResponseWriter, r *http.Request) {
+func handleCloseConnection(w http.ResponseWriter, r *http.Request) {
 	connectionID := chi.URLParam(r, "connectionID")
 	if connectionID == "" {
 		sendAPIResponse(w, r, nil, "connectionID is mandatory", http.StatusBadRequest)

api/schema/openapi.yaml

@@ -22,12 +22,12 @@ paths:
                 type: array
                 items:
                   $ref : '#/components/schemas/VersionInfo'
-  /sftp_connection:
+  /connection:
     get:
       tags:
       - connections
-      summary: Get the active sftp users and info about their uploads/downloads
-      operationId: get_sftp_connections
+      summary: Get the active users and info about their uploads/downloads
+      operationId: get_connections
       responses:
         200:
           description: successful operation
@@ -37,12 +37,12 @@ paths:
                 type: array
                 items:
                   $ref : '#/components/schemas/ConnectionStatus'
-  /sftp_connection/{connectionID}:
+  /connection/{connectionID}:
     delete:
       tags:
       - connections
-      summary: Terminate an active SFTP connection
-      operationId: close_sftp_connection
+      summary: Terminate an active connection
+      operationId: close_connection
       parameters: 
       - name: connectionID
         in: path
@@ -183,7 +183,7 @@ paths:
     get:
       tags:
       - users
-      summary: Returns an array with one or more SFTP users
+      summary: Returns an array with one or more users
       description: For security reasons password and public key are empty in the response
       operationId: get_users
       parameters:
@@ -261,7 +261,7 @@ paths:
     post:
       tags:
       - users
-      summary: Adds a new SFTP user
+      summary: Adds a new SFTP/SCP user
       operationId: add_user
       requestBody:
         required: true
@@ -562,15 +562,15 @@ components:
         max_sessions:
           type: integer
           format: int32
-          description: limit the sessions that an sftp user can open. 0 means unlimited
+          description: limit the sessions that an user can open. 0 means unlimited
         quota_size:
           type: integer
           format: int64
-          description: quota as size. 0 menas unlimited. Please note that quota is updated if files are added/removed via sftp otherwise a quota scan is needed
+          description: quota as size. 0 menas unlimited. Please note that quota is updated if files are added/removed via SFTP/SCP otherwise a quota scan is needed
         quota_files:
           type: integer
           format: int32
-          description: quota as number of files. 0 menas unlimited. Please note that quota is updated if files are added/removed via sftp otherwise a quota scan is needed
+          description: quota as number of files. 0 menas unlimited. Please note that quota is updated if files are added/removed via SFTP/SCP otherwise a quota scan is needed
         permissions:
           type: array
           items:
@@ -594,7 +594,7 @@ components:
           type: integer
           format: int32
           description: Maximum download bandwidth as KB/s, 0 means unlimited
-    SFTPTransfer:
+    Transfer:
       type: object
       properties:
         operation_type:
@@ -604,7 +604,7 @@ components:
             - download
         path:
           type: string
-          description: SFTP file path for the upload/download
+          description: SFTP/SCP file path for the upload/download
         start_time:
           type: integer
           format: int64
@@ -625,13 +625,13 @@ components:
           description: connected username
         connection_id:
           type: string
-          description: unique sftp connection identifier
+          description: unique connection identifier
         client_version:
           type: string
-          description: SFTP client version
+          description: SFTP/SCP client version
         remote_address:
           type: string
-          description: Remote address for the connected SFTP client
+          description: Remote address for the connected SFTP/SCP client
         connection_time:
           type: integer
           format: int64
@@ -640,10 +640,15 @@ components:
           type: integer
           format: int64
           description: last client activity as unix timestamp in milliseconds
+        protocol:
+          type: string
+          enum:
+            - SFTP
+            - SCP
         active_transfers:
           type: array
           items:
-            $ref : '#/components/schemas/SFTPTransfer'
+            $ref : '#/components/schemas/Transfer'
     QuotaScan:
       type: object
       properties: