Full featured and highly configurable SFTP server
SFTPGo is developed and tested on Linux. After each commit the code is automatically built and tested on Linux and macOS using Travis CI. Regularly the test cases are manually executed and pass on Windows. Other UNIX variants such as *BSD should work too.
Simple install the package to your $GOPATH with the go tool from shell:
$ go get -u github.com/drakkan/sftpgo
Make sure Git is installed on your machine and in your system's PATH.
SFTPGo depends on go-sqlite3 that is a CGO package and so it requires a C compiler at build time.
On Linux and macOS a compiler is easy to install or already installed, on Windows you need to download MinGW-w64 and build SFTPGo from its command prompt.
The compiler is a build time only dependency, it is not not required at runtime.
If you don't need SQLite, you can also get/build SFTPGo setting the environment variable GCO_ENABLED to 0, this way SQLite support will be disabled but PostgreSQL, MySQL, bbolt and memory data providers will work and you don't need a C compiler for building.
Version info, such as git commit and build date, can be embedded setting the following string variables at build time:
github.com/drakkan/sftpgo/utils.commitgithub.com/drakkan/sftpgo/utils.dateFor example you can build using the following command:
go build -i -ldflags "-s -w -X github.com/drakkan/sftpgo/utils.commit=`git describe --always --dirty` -X github.com/drakkan/sftpgo/utils.date=`date -u +%FT%TZ`" -o sftpgo
and you will get a version that includes git commit and build date like this one:
sftpgo -v
SFTPGo version: 0.9.0-dev-90607d4-dirty-2019-08-08T19:28:36Z
Alternately you can use distro packages:
git, gcc and go to build.git, gcc and go to build.git, gcc and go to build.For Linux, a systemd sample service can be found inside the source tree.
For macOS a launchd sample service can be found inside the source tree. The launchd plist assumes that sftpgo has /usr/local/opt/sftpgo as base directory.
On Windows you can run SFTPGo as Windows Service, please read the "Configuration" section below for more details.
The sftpgo executable can be used this way:
Usage:
sftpgo [command]
Available Commands:
help Help about any command
portable Serve a single directory
serve Start the SFTP Server
Flags:
-h, --help help for sftpgo
-v, --version
Use "sftpgo [command] --help" for more information about a command
The serve subcommand supports the following flags:
--config-dir string. Location of the config dir. This directory should contain the sftpgo configuration file and is used as the base for files with a relative path (eg. the private keys for the SFTP server, the SQLite or bblot database if you use SQLite or bbolt as data provider). The default value is "." or the value of SFTPGO_CONFIG_DIR environment variable.--config-file string. Name of the configuration file. It must be the name of a file stored in config-dir not the absolute path to the configuration file. The specified file name must have no extension we automatically load JSON, YAML, TOML, HCL and Java properties. The default value is "sftpgo" (and therefore sftpgo.json, sftpgo.yaml and so on are searched) or the value of SFTPGO_CONFIG_FILE environment variable.--log-compress boolean. Determine if the rotated log files should be compressed using gzip. Default false or the value of SFTPGO_LOG_COMPRESS environment variable (1 or true, 0 or false). It is unused if log-file-path is empty.--log-file-path string. Location for the log file, default "sftpgo.log" or the value of SFTPGO_LOG_FILE_PATH environment variable. Leave empty to write logs to the standard error.--log-max-age int. Maximum number of days to retain old log files. Default 28 or the value of SFTPGO_LOG_MAX_AGE environment variable. It is unused if log-file-path is empty.--log-max-backups int. Maximum number of old log files to retain. Default 5 or the value of SFTPGO_LOG_MAX_BACKUPS environment variable. It is unused if log-file-path is empty.--log-max-size int. Maximum size in megabytes of the log file before it gets rotated. Default 10 or the value of SFTPGO_LOG_MAX_SIZE environment variable. It is unused if log-file-path is empty.--log-verbose boolean. Enable verbose logs. Default true or the value of SFTPGO_LOG_VERBOSE environment variable (1 or true, 0 or false).If you don't configure any private host keys, the daemon will use id_rsa in the configuration directory. If that file doesn't exist, the daemon will attempt to autogenerate it (if the user that executes SFTPGo has write access to the config-dir). The server supports any private key format supported by crypto/ssh.
Before starting sftpgo a dataprovider must be configured.
Sample SQL scripts to create the required database structure can be found inside the source tree sql directory. The SQL scripts filename's is, by convention, the date as YYYYMMDD and the suffix .sql. You need to apply all the SQL scripts for your database ordered by name, for example 20190828.sql must be applied before 20191112.sql and so on.
The sftpgo configuration file contains the following sections:
bind_port, integer. The port used for serving SFTP requests. Default: 2022bind_address, string. Leave blank to listen on all available network interfaces. Default: ""idle_timeout, integer. Time in minutes after which an idle client will be disconnected. 0 menas disabled. Default: 15max_auth_tries integer. Maximum number of authentication attempts permitted per connection. If set to a negative number, the number of attempts are unlimited. If set to zero, the number of attempts are limited to 6.umask, string. Umask for the new files and directories. This setting has no effect on Windows. Default: "0022"banner, string. Identification string used by the server. Leave empty to use the default banner. Default "SFTPGo_version"upload_mode integer. 0 means standard, the files are uploaded directly to the requested path. 1 means atomic: files are uploaded to a temporary path and renamed to the requested path when the client ends the upload. Atomic mode avoids problems such as a web server that serves partial files when the files are being uploaded. In atomic mode if there is an upload error the temporary file is deleted and so the requested upload path will not contain a partial file. 2 means atomic with resume support: as atomic but if there is an upload error the temporary file is renamed to the requested path and not deleted, this way a client can reconnect and resume the upload.actions, struct. It contains the command to execute and/or the HTTP URL to notify and the trigger conditions
execute_on, list of strings. Valid values are download, upload, delete, rename. Actions will be not executed if an error is detected and so a partial file is uploaded or downloaded. The upload condition includes both uploads to new files and overwrite of existing files. Leave empty to disable actions.command, string. Absolute path to the command to execute. Leave empty to disable. The command is invoked with the following arguments:
action, any valid execute_on stringusername, user who did the actionpath to the affected file. For rename action this is the old file nametarget_path, non empty for rename action, this is the new file namehttp_notification_url, a valid URL. An HTTP GET request will be executed to this URL. Leave empty to disable. The query string will contain the following parameters that have the same meaning of the command's arguments:
actionusernamepathtarget_path, added for rename action onlykeys, 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.enable_scp, boolean. Default disabled. Set to true to enable 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. Please do accurate tests yourself before enabling SCP and let us known if something does not work as expected for your use cases. SCP between two remote hosts is supported using the -3 scp option.kex_algorithms, list of strings. Available KEX (Key Exchange) algorithms in preference order. Leave empty to use default values. The supported values can be found here: crypto/sshciphers, list of strings. Allowed ciphers. Leave empty to use default values. The supported values can be found here: crypto/sshmacs, list of strings. available MAC (message authentication code) algorithms in preference order. Leave empty to use default values. The supported values can be found here: crypto/sshlogin_banner_file, path to the login banner file. The contents of the specified file, if any, are sent to the remote user before authentication is allowed. It can be a path relative to the config dir or an absolute one. Leave empty to send no login bannersetstat_mode, integer. 0 means "normal mode": requests for changing permissions and owner/group are executed. 1 means "ignore mode": requests for changing permissions and owner/group are silently ignored.driver, string. Supported drivers are sqlite, mysql, postgresql, bolt, memoryname, 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.host, string. Database host. Leave empty for drivers sqlite, bolt and memoryport, integer. Database port. Leave empty for drivers sqlite, bolt and memoryusername, string. Database user. Leave empty for drivers sqlite, bolt and memorypassword, string. Database password. Leave empty for drivers sqlite, bolt and memorysslmode, integer. Used for drivers mysql and postgresql. 0 disable SSL/TLS connections, 1 require ssl, 2 set ssl mode to verify-ca for driver postgresql and skip-verify for driver mysql, 3 set ssl mode to verify-full for driver postgresql and preferred for driver mysqlconnectionstring, string. Provide a custom database connection string. If not empty this connection string will be used instead of build one using the previous parameters. Leave empty for drivers bolt and memoryusers_table, string. Database table for SFTP usersmanage_users, integer. Set to 0 to disable users management, 1 to enabletrack_quota, integer. Set the preferred way to track users quota between the following choices:
pool_size, integer. Sets the maximum number of open connections for mysql and postgresql driver. Default 0 (unlimited)users_base_dir, string. Users' default base directory. If no home dir is defined while adding a new user, and this value is a valid absolute path, then the user home dir will be automatically defined as the path obtained joining the base dir and the usernameactions, struct. It contains the command to execute and/or the HTTP URL to notify and the trigger conditions
execute_on, list of strings. Valid values are add, update, delete. update action will not be fired for internal updates such as the last login or the user quota fields.command, string. Absolute path to the command to execute. Leave empty to disable. The command is invoked with the following arguments that identify the user added, updated or deleted:
action, any valid execute_on stringusernameIDstatusexpiration_date, as unix timestamp in millisecondshome_diruidgidhttp_notification_url, a valid URL. The action is added to the query string. For example <http_notification_url>?action=update. An HTTP POST request will be executed to this URL. The user is sent serialized as json inside the POST body. Leave empty to disable.bind_port, integer. The port used for serving HTTP requests. Set to 0 to disable HTTP server. Default: 8080bind_address, string. Leave blank to listen on all available network interfaces. Default: "127.0.0.1"templates_path, string. Path to the HTML web templates. This can be an absolute path or a path relative to the config dirstatic_files_path, string. Path to the static files for the web interface. This can be an absolute path or a path relative to the config dirHere is a full example showing the default config in JSON format:
{
"sftpd": {
"bind_port": 2022,
"bind_address": "",
"idle_timeout": 15,
"max_auth_tries": 0,
"umask": "0022",
"banner": "",
"upload_mode": 0,
"actions": {
"execute_on": [],
"command": "",
"http_notification_url": ""
},
"keys": [],
"enable_scp": false,
"kex_algorithms": [],
"ciphers": [],
"macs": [],
"login_banner_file": "",
"setstat_mode": 0
},
"data_provider": {
"driver": "sqlite",
"name": "sftpgo.db",
"host": "",
"port": 5432,
"username": "",
"password": "",
"sslmode": 0,
"connection_string": "",
"users_table": "users",
"manage_users": 1,
"track_quota": 2,
"pool_size": 0,
"users_base_dir": "",
"actions": {
"execute_on": [],
"command": "",
"http_notification_url": ""
}
},
"httpd": {
"bind_port": 8080,
"bind_address": "127.0.0.1",
"templates_path": "templates",
"static_files_path": "static"
}
}
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:
"keys": [
{
"private_key": "id_rsa"
},
{
"private_key": "id_ecdsa"
}
]
The configuration can be read from JSON, TOML, YAML, HCL, envfile and Java properties config files, if your config-file flag is set to sftpgo (default value) you need to create a configuration file called sftpgo.json or sftpgo.yaml and so on inside config-dir.
You can also override all the available configuration options using environment variables, sftpgo will check for environment variables with a name matching the key uppercased and prefixed with the SFTPGO_. You need to use __ to traverse a struct.
Let's see some examples:
bind_port you need to define the env var SFTPGO_SFTPD__BIND_PORTexecute_on actions you need to define the env var SFTPGO_SFTPD__ACTIONS__EXECUTE_ON for example SFTPGO_SFTPD__ACTIONS__EXECUTE_ON=upload,downloadPlease note that to override configuration options with environment variables a configuration file containing the options to override is required. You can, for example, deploy the default configuration file and then override the options you need to customize using environment variables.
To start the SFTP Server with the default values for the command line flags simply use:
sftpgo serve
On Windows you can register SFTPGo as Windows Service, take a look at the CLI usage to learn how:
sftpgo.exe service --help
Install, Uninstall, Start, Stop and retrieve status for SFTPGo Windows Service
Usage:
sftpgo service [command]
Available Commands:
install Install SFTPGo as Windows Service
start Start SFTPGo Windows Service
status Retrieve the status for the SFTPGo Windows Service
stop Stop SFTPGo Windows Service
uninstall Uninstall SFTPGo Windows Service
Flags:
-h, --help help for service
Use "sftpgo service [command] --help" for more information about a command.
install subcommand accepts the same flags valid for serve.
After installing as Windows Service please remember to allow network access to the SFTPGo executable using something like this:
netsh advfirewall firewall add rule name="SFTPGo Service" dir=in action=allow program="C:\Program Files\SFTPGo\sftpgo.exe"
or through the Windows Firewall GUI.
SFTPGo allows to share a single directory on demand using the portable subcommand:
sftpgo portable --help
To serve the current working directory with auto generated credentials simply use:
sftpgo portable
Please take a look at the usage below to customize the serving parameters
Usage:
sftpgo portable [flags]
Flags:
-C, --advertise-credentials If the SFTP service is advertised via multicast DNS this flag allows to put username/password inside the advertised TXT record
-S, --advertise-service Advertise SFTP service using multicast DNS (default true)
-d, --directory string Path to the directory to serve. This can be an absolute path or a path relative to the current directory (default ".")
-h, --help help for portable
-l, --log-file-path string Leave empty to disable logging
-p, --password string Leave empty to use an auto generated value
-g, --permissions strings User's permissions. "*" means any permission (default [list,download])
-k, --public-key strings
--scp Enable SCP
-s, --sftpd-port int 0 means a random non privileged port
-u, --username string Leave empty to use an auto generated value
In portable mode SFTPGo can advertise the SFTP service and, optionally, the credentials via multicast DNS, so there is a standard way to discover the service and to automatically connect to it.
Here is an example of the advertised service including credentials as seen using avahi-browse:
= enp0s31f6 IPv4 SFTPGo portable 53705 SFTP File Transfer local
hostname = [p1.local]
address = [192.168.1.230]
port = [53705]
txt = ["password=EWOo6pJe" "user=user" "version=0.9.3-dev-b409523-dirty-2019-10-26T13:43:32Z"]
For each account the following properties can be configured:
usernamepassword used for password authentication. For users created using SFTPGo REST API if the password has no known hashing algo prefix it will be stored using argon2id. SFTPGo supports checking passwords stored with bcrypt, pbkdf2 and sha512crypt too. For pbkdf2 the supported format is $<algo>$<iterations>$<salt>$<hashed pwd base64 encoded>, where algo is pbkdf2-sha1 or pbkdf2-sha256 or pbkdf2-sha512. For example the pbkdf2-sha256 of the word password using 150000 iterations and E86a9YMX3zC7 as salt must be stored as $pbkdf2-sha256$150000$E86a9YMX3zC7$R5J62hsSq+pYw00hLLPKBbcGXmq7fj5+/M0IFoYtZbo=. For bcrypt the format must be the one supported by golang's crypto/bcrypt package, for example the password secret with cost 14 must be stored as $2a$14$ajq8Q7fbtFRQvXpdCq7Jcuy.Rx1h/L4J60Otx.gyNLbAYctGMJ9tK. For sha512crypt we support the format used in /etc/shadow with the $6$ prefix, this is useful if you are migrating from Unix system user accounts. Using the REST API you can send a password hashed as bcrypt, pbkdf2 or sha512crypt and it will be stored as is.public_keys array of public keys. At least one public key or the password is mandatory.status 1 means "active", 0 "inactive". An inactive account cannot login.expiration_date expiration date as unix timestamp in milliseconds. An expired account cannot login. 0 means no expiration.home_dir The user cannot upload or download files outside this directory. Must be an absolute path.uid, gid. If sftpgo runs as root system user then the created files and directories will be assigned to this system uid/gid. Ignored on windows and if sftpgo runs as non root user: in this case files and directories for all SFTP users will be owned by the system user that runs sftpgo.max_sessions maximum concurrent sessions. 0 means unlimited.quota_size maximum size allowed as bytes. 0 means unlimited.quota_files maximum number of files allowed. 0 means unlimited.permissions the following permissions are supported:
* all permissions are grantedlist list items is alloweddownload download files is allowedupload upload files is allowedoverwrite overwrite an existing file, while uploading, is allowed. upload permission is required to allow file overwritedelete delete files or directories is allowedrename rename files or directories is allowedcreate_dirs create directories is allowedcreate_symlinks create symbolic links is allowedchmod changing file or directory permissions is allowedchown changing file or directory owner and group is allowedupload_bandwidth maximum upload bandwidth as KB/s, 0 means unlimited.download_bandwidth maximum download bandwidth as KB/s, 0 means unlimited.These properties are stored inside the data provider. If you want to use your existing accounts, you can create a database view. Since a view is read only, you have to disable user management and quota tracking so SFTPGo will never try to write to the view.
SFTPGo exposes REST API to manage users and quota and to get real time reports for the active connections with possibility of forcibly closing a connection.
If quota tracking is enabled in sftpgo configuration file, then the used size and number of files are updated each time a file is added/removed. If files are added/removed not using SFTP or if you change track_quota from 2 to 1, you can rescan the user home dir and update the used quota using the REST API.
REST API is designed to run on localhost or on a trusted network, if you need HTTPS and/or authentication you can setup a reverse proxy using an HTTP Server such as Apache or NGNIX.
For example you can keep SFTPGo listening on localhost and expose it externally configuring a reverse proxy using Apache HTTP Server this way:
ProxyPass /api/v1 http://127.0.0.1:8080/api/v1
ProxyPassReverse /api/v1 http://127.0.0.1:8080/api/v1
and you can add authentication with something like this:
<Location /api/v1>
AuthType Digest
AuthName "Private"
AuthDigestDomain "/api/v1"
AuthDigestProvider file
AuthUserFile "/etc/httpd/conf/auth_digest"
Require valid-user
</Location>
and, of course, you can configure the web server to use HTTPS.
The OpenAPI 3 schema for the exposed API can be found inside the source tree: openapi.yaml.
A sample CLI client for the REST API can be found inside the source tree scripts directory.
You can also generate your own REST client, in your preferred programming language or even bash scripts, using an OpenAPI generator such as swagger-codegen or OpenAPI Generator
SFTPGo exposes Prometheus metrics at the /metrics HTTP endpoint.
Several counters and gauges are available, for example:
Please check the /metrics page for more details.
You can easily build your own interface using the exposed REST API, anyway SFTPGo provides also a very basic builtin web interface that allows to manage users and connections.
With the default httpd configuration, the web admin is available at the following URL:
If you need HTTPS and/or authentication you can setup a reverse proxy as explained for the REST API.
Inside the log file each line is a JSON struct, each struct has a sender fields that identify the log type.
The logs can be divided into the following categories:
sftpgo:
sender string. This is generally the package name that emits the logtime string. Date/time with millisecond precisionlevel stringmessage stringsender string. Upload or Downloadtime string. Date/time with millisecond precisionlevel stringelapsed_ms, int64. Elapsed time, as milliseconds, for the upload/downloadsize_bytes, int64. Size, as bytes, of the download/uploadusername, stringfile_path stringconnection_id string. Unique connection identifierprotocol string. SFTP or SCPsender string. Rename, Rmdir, Mkdir, Symlink, Remove, Chmod, Chownlevel stringusername, stringfile_path stringtarget_path stringfilemode string. Valid for sender Chmod otherwise emptyuid integer. Valid for sender Chown otherwise -1gid integer. Valid for sender Chown otherwise -1connection_id string. Unique connection identifierprotocol string. SFTP or SCPsender string. httpdlevel stringremote_addr string. IP and port of the remote clientproto string, for example HTTP/1.1method string. HTTP method (GET, POST, PUT, DELETE etc.)user_agent stringuri string. Full uriresp_status integer. HTTP response status coderesp_size integer. Size in bytes of the HTTP responseelapsed_ms int64. Elapsed time, as milliseconds, to complete the requestrequest_id string. Unique request identifiersender string. connection_failedlevel stringusername, string. Can be empty if the connection is closed before an authentication attemptclient_ip string.login_type string. Can be public_key, password or no_auth_tryederror string. Optional error descriptionThe connection failed logs can be used for better integration in tools such as Fail2ban
Some code was initially taken from Pterodactyl sftp server
GNU GPLv3