⚡ Add private key and passphrase fields to SFTP credentials (#1136)

* ⚡ Add private key and passphrase fields to credentials

* ⚡ Small improvement

packages/nodes-base/credentials/Sftp.credentials.ts

@@ -38,5 +38,27 @@ export class Sftp implements ICredentialType {
 			},
 			default: '',
 		},
+		{
+			displayName: 'Private Key',
+			name: 'privateKey',
+			required: true,
+			type: 'string' as NodePropertyTypes,
+			typeOptions: {
+				alwaysOpenEditWindow: true,	
+			},
+			default: '',
+			description: 'String that contains a private key for either key-based or hostbased user authentication (OpenSSH format).',
+		},
+		{
+			displayName: 'Passphrase',
+			name: 'passphrase',
+			typeOptions: {
+				password: true,
+			},
+			required: true,
+			type: 'string' as NodePropertyTypes,
+			default: '',
+			description: 'For an encrypted private key, this is the passphrase used to decrypt it',
+		},
 	];
 }