From d829810b8b1ba8eb7eed16e07c18982b67ed28c9 Mon Sep 17 00:00:00 2001 From: Trevor Slocum Date: Sat, 4 Jan 2020 13:22:45 -0800 Subject: [PATCH] Initial commit --- .builds/amd64_freebsd.yml | 14 ++++ .builds/amd64_linux_alpine.yml | 14 ++++ .gitignore | 5 ++ CHANGELOG | 2 + CONFIGURATION.md | 33 ++++++++ LICENSE | 21 ++++++ README.md | 28 +++++++ config.go | 38 ++++++++++ go.mod | 12 +++ go.sum | 20 +++++ goreleaser.yml | 33 ++++++++ main.go | 115 ++++++++++++++++++++++++++++ pkg/gate/portal.go | 133 +++++++++++++++++++++++++++++++++ 13 files changed, 468 insertions(+) create mode 100644 .builds/amd64_freebsd.yml create mode 100644 .builds/amd64_linux_alpine.yml create mode 100644 .gitignore create mode 100644 CHANGELOG create mode 100644 CONFIGURATION.md create mode 100644 LICENSE create mode 100644 README.md create mode 100644 config.go create mode 100644 go.mod create mode 100644 go.sum create mode 100644 goreleaser.yml create mode 100644 main.go create mode 100644 pkg/gate/portal.go diff --git a/.builds/amd64_freebsd.yml b/.builds/amd64_freebsd.yml new file mode 100644 index 0000000..bd84fa6 --- /dev/null +++ b/.builds/amd64_freebsd.yml @@ -0,0 +1,14 @@ +arch: amd64 +environment: + PROJECT_NAME: 'sshtargate' + CGO_ENABLED: '1' + GO111MODULE: 'on' +image: freebsd/latest +packages: + - go +sources: + - https://git.sr.ht/~tslocum/sshtargate +tasks: + - test: | + cd $PROJECT_NAME + go test ./... diff --git a/.builds/amd64_linux_alpine.yml b/.builds/amd64_linux_alpine.yml new file mode 100644 index 0000000..3a88b5f --- /dev/null +++ b/.builds/amd64_linux_alpine.yml @@ -0,0 +1,14 @@ +arch: x86_64 +environment: + PROJECT_NAME: 'sshtargate' + CGO_ENABLED: '1' + GO111MODULE: 'on' +image: alpine/edge +packages: + - go +sources: + - https://git.sr.ht/~tslocum/sshtargate +tasks: + - test: | + cd $PROJECT_NAME + go test ./... diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..d78bbae --- /dev/null +++ b/.gitignore @@ -0,0 +1,5 @@ +.idea/ +dist/ +vendor/ +sshtargate +*.sh diff --git a/CHANGELOG b/CHANGELOG new file mode 100644 index 0000000..8da6a6f --- /dev/null +++ b/CHANGELOG @@ -0,0 +1,2 @@ +0.1.0: +- Initial release diff --git a/CONFIGURATION.md b/CONFIGURATION.md new file mode 100644 index 0000000..48e129b --- /dev/null +++ b/CONFIGURATION.md @@ -0,0 +1,33 @@ +This document explains how to configure sshtargate. + +# Configuration + +Specify the path to a configuration file with ```--config``` or create a file +at the default path of ```~/.config/sshtargate/config.yaml```. + +Define one or more **portals** by name/label with the following options: + +- **command** - Command to execute +- **host** - One or more addresses to listen for connections + +# Example config.yaml + +``` +portals: + date and time: + command: date + host: + - localhost:19001 + uname: + command: uname -a + host: + - localhost:19002 + process list: + command: ps -aux + host: + - localhost:19003 + system monitor: + command: htop + host: + - localhost:19004 +``` diff --git a/LICENSE b/LICENSE new file mode 100644 index 0000000..7c20f89 --- /dev/null +++ b/LICENSE @@ -0,0 +1,21 @@ +MIT License + +Copyright (c) 2020 Trevor Slocum + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in all +copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +SOFTWARE. diff --git a/README.md b/README.md new file mode 100644 index 0000000..bee7a35 --- /dev/null +++ b/README.md @@ -0,0 +1,28 @@ +# sshtargate +[![GoDoc](https://godoc.org/git.sr.ht/~tslocum/sshtargate?status.svg)](https://godoc.org/git.sr.ht/~tslocum/sshtargate) +[![builds.sr.ht status](https://builds.sr.ht/~tslocum/sshtargate.svg)](https://builds.sr.ht/~tslocum/sshtargate) +[![Donate](https://img.shields.io/liberapay/receives/rocketnine.space.svg?logo=liberapay)](https://liberapay.com/rocketnine.space) + +Host SSH portals to applications + +## Install + +Choose one of the following methods: + +### Download + +[**Download sshtargate**](https://sshtargate.rocketnine.space/download/?sort=name&order=desc) + +### Compile + +``` +GO111MODULE=on go get git.sr.ht/~tslocum/sshtargate +``` + +## Configure + +See [CONFIGURATION.md](https://man.sr.ht/~tslocum/sshtargate/CONFIGURATION.md) + +## Support + +Please share issues/suggestions [here](https://todo.sr.ht/~tslocum/sshtargate). diff --git a/config.go b/config.go new file mode 100644 index 0000000..b72b4a0 --- /dev/null +++ b/config.go @@ -0,0 +1,38 @@ +package main + +import ( + "fmt" + "io/ioutil" + "log" + + "gopkg.in/yaml.v2" +) + +type PortalConfig struct { + Command string + Host []string `yaml:",flow"` +} + +type Config struct { + Portals map[string]*PortalConfig +} + +var config = &Config{} + +func readConfig(configPath string) error { + configData, err := ioutil.ReadFile(configPath) + if err != nil { + return fmt.Errorf("failed to read file: %s", err) + } + + err = yaml.Unmarshal(configData, config) + if err != nil { + return fmt.Errorf("failed to parse file: %s", err) + } + + if len(config.Portals) == 0 { + log.Println("Warning: No portals are defined") + } + + return nil +} diff --git a/go.mod b/go.mod new file mode 100644 index 0000000..169460b --- /dev/null +++ b/go.mod @@ -0,0 +1,12 @@ +module git.sr.ht/~tslocum/sshtargate + +go 1.13 + +require ( + github.com/anmitsu/go-shlex v0.0.0-20161002113705-648efa622239 + github.com/creack/pty v1.1.9 + github.com/gliderlabs/ssh v0.2.2 + golang.org/x/crypto v0.0.0-20191227163750-53104e6ec876 + golang.org/x/sys v0.0.0-20200103143344-a1369afcdac7 // indirect + gopkg.in/yaml.v2 v2.2.7 +) diff --git a/go.sum b/go.sum new file mode 100644 index 0000000..97d5eb3 --- /dev/null +++ b/go.sum @@ -0,0 +1,20 @@ +github.com/anmitsu/go-shlex v0.0.0-20161002113705-648efa622239 h1:kFOfPq6dUM1hTo4JG6LR5AXSUEsOjtdm0kw0FtQtMJA= +github.com/anmitsu/go-shlex v0.0.0-20161002113705-648efa622239/go.mod h1:2FmKhYUyUczH0OGQWaF5ceTx0UBShxjsH6f8oGKYe2c= +github.com/creack/pty v1.1.9 h1:uDmaGzcdjhF4i/plgjmEsriH11Y0o7RKapEf/LDaM3w= +github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E= +github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568 h1:BHsljHzVlRcyQhjrss6TZTdY2VfCqZPbv5k3iBFa2ZQ= +github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568/go.mod h1:xEzjJPgXI435gkrCt3MPfRiAkVrwSbHsst4LCFVfpJc= +github.com/gliderlabs/ssh v0.2.2 h1:6zsha5zo/TWhRhwqCD3+EarCAgZ2yN28ipRnGPnwkI0= +github.com/gliderlabs/ssh v0.2.2/go.mod h1:U7qILu1NlMHj9FlMhZLlkCdDnU1DBEAqr0aevW3Awn0= +golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w= +golang.org/x/crypto v0.0.0-20191227163750-53104e6ec876 h1:sKJQZMuxjOAR/Uo2LBfU90onWEf1dF4C+0hPJCc9Mpc= +golang.org/x/crypto v0.0.0-20191227163750-53104e6ec876/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto= +golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg= +golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY= +golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs= +golang.org/x/sys v0.0.0-20200103143344-a1369afcdac7 h1:/W9OPMnnpmFXHYkcp2rQsbFUbRlRzfECQjmAFiOyHE8= +golang.org/x/sys v0.0.0-20200103143344-a1369afcdac7/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs= +golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ= +gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0= +gopkg.in/yaml.v2 v2.2.7 h1:VUgggvou5XRW9mHwD/yXxIYSMtY0zoKQf/v226p2nyo= +gopkg.in/yaml.v2 v2.2.7/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI= diff --git a/goreleaser.yml b/goreleaser.yml new file mode 100644 index 0000000..6e66c43 --- /dev/null +++ b/goreleaser.yml @@ -0,0 +1,33 @@ +project_name: sshtargate + +builds: + - + id: sshtargate + binary: sshtargate + env: + - CGO_ENABLED=0 + ldflags: + - -s -w -X git.sr.ht/~tslocum/sshtargate/version={{.Version}} + goos: + - darwin + - freebsd + - linux + goarch: + - 386 + - amd64 +archives: + - + id: sshtargate + builds: + - sshtargate + replacements: + 386: i386 + format_overrides: + - goos: windows + format: zip + files: + - ./*.md + - CHANGELOG + - LICENSE +checksum: + name_template: 'checksums.txt' diff --git a/main.go b/main.go new file mode 100644 index 0000000..bf6dd69 --- /dev/null +++ b/main.go @@ -0,0 +1,115 @@ +package main + +import ( + "flag" + "fmt" + "log" + "os" + "os/signal" + "path" + "strings" + "sync" + "syscall" + + "git.sr.ht/~tslocum/sshtargate/pkg/gate" + "github.com/anmitsu/go-shlex" +) + +const ( + version = "0.0.0" + + versionInfo = `sshtargate - Host SSH portals to applications - v` + version + ` +https://git.sr.ht/~tslocum/sshtargate +The MIT License (MIT) +Copyright (c) 2020 Trevor Slocum +` +) + +var ( + printVersionInfo bool + configPath string + + portals []*gate.Portal + portalsLock = new(sync.Mutex) + + done = make(chan bool) +) + +func main() { + flag.BoolVar(&printVersionInfo, "version", false, "print version information and exit") + flag.StringVar(&configPath, "config", "", "path to configuration file") + flag.Parse() + + if printVersionInfo { + fmt.Print(versionInfo) + return + } + + // TODO: Allow portals to be specified via arguments + + // TODO: Catch SIGHUP + sigc := make(chan os.Signal, 1) + signal.Notify(sigc, + syscall.SIGINT, + syscall.SIGTERM) + go func() { + <-sigc + + done <- true + }() + + log.Println("Initializing sshtargate...") + + if configPath == "" { + homedir, err := os.UserHomeDir() + if err == nil && homedir != "" { + configPath = path.Join(homedir, ".config", "sshtargate", "config.yaml") + } + } + + err := readConfig(configPath) + if err != nil { + log.Fatalf("failed to read configuration file %s: %s", configPath, err) + } + + for pname, pcfg := range config.Portals { + cs, err := shlex.Split(pcfg.Command, true) + if err != nil { + log.Fatalf("failed to split command %s", pcfg.Command) + } + + pname, pcfg := pname, pcfg // Capture + go func() { + wg := new(sync.WaitGroup) + + for _, address := range pcfg.Host { + wg.Add(1) + address := address // Capture + + go func() { + p, err := gate.NewPortal(pname, address, cs) + if err != nil { + log.Fatalf("failed to start portal %s on %s: %s", pname, address, err) + } + + portalsLock.Lock() + portals = append(portals, p) + portalsLock.Unlock() + + wg.Done() + }() + } + + wg.Wait() + log.Printf("Opened portal %s on %s to %s", pname, strings.Join(pcfg.Host, ","), pcfg.Command) + }() + } + + <-done + + portalsLock.Lock() + for _, p := range portals { + p.Shutdown() + } + portalsLock.Unlock() +} diff --git a/pkg/gate/portal.go b/pkg/gate/portal.go new file mode 100644 index 0000000..0046d09 --- /dev/null +++ b/pkg/gate/portal.go @@ -0,0 +1,133 @@ +package gate + +import ( + "context" + "errors" + "fmt" + "io" + "os" + "os/exec" + "path" + "syscall" + "time" + "unsafe" + + "github.com/creack/pty" + "github.com/gliderlabs/ssh" + gossh "golang.org/x/crypto/ssh" +) + +const ( + ListenTimeout = 1 * time.Second + IdleTimeout = 1 * time.Minute +) + +type Portal struct { + Name string + Address string + Command []string + Server *ssh.Server +} + +func setWinsize(f *os.File, w, h int) { + syscall.Syscall(syscall.SYS_IOCTL, f.Fd(), uintptr(syscall.TIOCSWINSZ), + uintptr(unsafe.Pointer(&struct{ h, w, x, y uint16 }{uint16(h), uint16(w), 0, 0}))) +} + +func NewPortal(name string, address string, command []string) (*Portal, error) { + if address == "" { + return nil, errors.New("no address supplied") + } else if command == nil || command[0] == "" { + return nil, errors.New("no command supplied") + } + + server := &ssh.Server{ + Addr: address, + IdleTimeout: IdleTimeout, + Handler: func(sshSession ssh.Session) { + ptyReq, winCh, isPty := sshSession.Pty() + if !isPty { + io.WriteString(sshSession, "failed to start command: non-interactive terminals are not supported\n") + sshSession.Exit(1) + return + } + + cmdCtx, cancelCmd := context.WithCancel(sshSession.Context()) + defer cancelCmd() + + var args []string + if len(command) > 1 { + args = command[1:] + } + + cmd := exec.CommandContext(cmdCtx, command[0], args...) + cmd.Env = append(cmd.Env, fmt.Sprintf("TERM=%s", ptyReq.Term)) + + f, err := pty.Start(cmd) + if err != nil { + io.WriteString(sshSession, fmt.Sprintf("failed to start command: failed to initialize pseudo-terminal: %s\n", err)) + sshSession.Exit(1) + return + } + defer f.Close() + + go func() { + for win := range winCh { + setWinsize(f, win.Width, win.Height) + } + }() + + go func() { + io.Copy(f, sshSession) + }() + io.Copy(sshSession, f) + + cmd.Wait() + }, + PtyCallback: func(ctx ssh.Context, pty ssh.Pty) bool { + return true + }, + PublicKeyHandler: func(ctx ssh.Context, key ssh.PublicKey) bool { + return true + }, + PasswordHandler: func(ctx ssh.Context, password string) bool { + return true + }, + KeyboardInteractiveHandler: func(ctx ssh.Context, challenger gossh.KeyboardInteractiveChallenge) bool { + return true + }, + } + + homeDir, err := os.UserHomeDir() + if err != nil { + return nil, fmt.Errorf("failed to retrieve user home dir: %s", err) + } + + err = server.SetOption(ssh.HostKeyFile(path.Join(homeDir, ".ssh", "id_rsa"))) + if err != nil { + return nil, fmt.Errorf("failed to set host key file: %s", err) + } + + t := time.NewTimer(ListenTimeout) + errs := make(chan error) + go func() { + err := server.ListenAndServe() + if err != nil { + errs <- fmt.Errorf("failed to start SSH server: %s", err) + } + }() + select { + case err = <-errs: + return nil, err + case <-t.C: + // Server started + } + + p := Portal{Name: name, Address: address, Command: command, Server: server} + + return &p, nil +} + +func (p *Portal) Shutdown() { + p.Server.Close() +}