Improve documentation

README.md

@@ -84,8 +84,8 @@ The `sftpgo.conf` configuration file contains the following sections:
             - `username`
             - `path`
             - `target_path`, added for `rename` action only
-    - `keys`, struct array. It contains the daemon's private keys
-        - `private_key`, path to the private key file
+    - `keys`, struct array. It contains the daemon's private keys. If empty or missing the daemon will search or try to generate `id_rsa` in the configuration directory.
+        - `private_key`, path to the private key file. It can be a path relative to the config dir or an absolute one.
 - **"data_provider"**, the configuration for the data provider
     - `driver`, string. Supported drivers are `sqlite`, `mysql`, `postgresql`
     - `name`, string. Database name. For driver `sqlite` this can be the database name relative to the config dir or the absolute path to the SQLite database.
@@ -121,14 +121,7 @@ Here is a full example showing the default config:
       "command": "",
       "http_notification_url": ""
     },
-    "keys": [
-      {
-        "private_key": "id_rsa"
-      },
-      {
-        "private_key": "id_ecdsa"
-      }
-    ]
+    "keys": []
   },
   "data_provider": {
     "driver": "sqlite",
@@ -150,6 +143,19 @@ Here is a full example showing the default config:
 }
 ```
 
+If you want to use a private key that use an algorithm different from RSA or more than one private key then replace the empty `keys` array with something like this:
+
+```json
+"keys": [
+  {
+    "private_key": "id_rsa"
+  },
+  {
+    "private_key": "id_ecdsa"
+  }
+]
+```
+
 ## Account's configuration properties
 
 For each account the following properties can be configured:

sftpd/server.go

@@ -49,9 +49,9 @@ type Configuration struct {
 	Keys []Key `json:"keys"`
 }
 
-// Struct containing information about host keys
+// Key contains information about host keys
 type Key struct {
-	// The private key
+	// The private key path relative to the configuration directory or absolute
 	PrivateKey string `json:"private_key"`
 }
 
@@ -118,7 +118,7 @@ func (c Configuration) Initialize(configDir string) error {
 			return err
 		}
 
-		// Add our private key to the server configuration.
+		// Add private key to the server configuration.
 		serverConfig.AddHostKey(private)
 	}
 

sftpgo.conf

@@ -10,7 +10,8 @@
       "execute_on": [],
       "command": "",
       "http_notification_url": ""
-    }
+    },
+    "keys": []
   },
   "data_provider": {
     "driver": "sqlite",