Initial commit

README.md

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+# LSF - LSF S... F...  rekusives akronym!!!111elf
+
+## TODO
+
+- documentation
+- tests
+- webapi

cmd/lsf/main.go

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+// Command lsf provides functions to use the lsf with the commandline.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"path"
+	"strings"
+	"syscall"
+
+	"git.marceltransier.de/lsf"
+	"github.com/pkg/errors"
+	"golang.org/x/crypto/ssh/terminal"
+)
+
+var (
+	sessionCache string
+	username     string
+)
+
+func init() {
+	homeDir, err := os.UserHomeDir()
+	if err != nil {
+		log.Fatal(err)
+	}
+	defaultCacheDir := path.Join(homeDir, ".cache/go-lsf/sessions")
+	flag.StringVar(&sessionCache, "session-cache", defaultCacheDir, "path where the session tokens are located")
+	flag.StringVar(&username, "username", "", "username to login with in lsf")
+	flag.Parse()
+
+	err = os.MkdirAll(sessionCache, os.ModePerm)
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+func main() {
+	if len(username) == 0 {
+		var err error
+		username, err = readUsername()
+		if err != nil {
+			log.Fatal(err)
+		}
+	}
+
+	s, err := session(username)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Printf("s: %+v\n", s)
+}
+
+func readUsername() (string, error) {
+	var username string
+	fmt.Print("Username: ")
+	_, err := fmt.Scanf("%s", &username)
+	if err != nil {
+		return "", errors.Wrap(err, "could not read username")
+	}
+	return username, nil
+}
+
+func readPassword() (string, error) {
+	var password string
+	fmt.Print("Password: ")
+	b, err := terminal.ReadPassword(int(syscall.Stdin))
+	if err != nil {
+		return "", errors.Wrap(err, "could not read password")
+	}
+	fmt.Print("\n")
+	password = string(b)
+	return password, nil
+}
+
+func session(username string) (*lsf.Session, error) {
+	sessionPath := path.Join(sessionCache, username)
+	sessionFile, err := os.Open(sessionPath)
+	if err != nil {
+		pErr, ok := err.(*os.PathError)
+		if !ok {
+			return nil, err
+		}
+		errno, ok := pErr.Unwrap().(syscall.Errno)
+		if !ok {
+			return nil, err
+		}
+		if errno != syscall.ENOENT {
+			log.Fatal(err)
+		}
+		log.Printf("no session for %s cached\n", username)
+		return login(username)
+	}
+	defer sessionFile.Close()
+
+	b, err := ioutil.ReadAll(sessionFile)
+	if err != nil {
+		return nil, errors.Wrapf(err, "could not read session file %s", sessionPath)
+	}
+	sid := strings.TrimSuffix(string(b), "\n")
+	s := &lsf.Session{
+		SID: sid,
+	}
+	valid, err := s.Valid()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not check session")
+	}
+	if !valid {
+		fmt.Println("session is not valid")
+		err := os.Remove(sessionPath)
+		if err != nil {
+			log.Println(errors.Wrap(err, "could not remove invalid session file"))
+		}
+		return login(username)
+	}
+	return s, nil
+}
+
+func login(username string) (*lsf.Session, error) {
+	password, err := readPassword()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not login")
+	}
+	s, err := lsf.Login(username, password)
+	if err != nil {
+		return nil, err
+	}
+	sessionPath := path.Join(sessionCache, username)
+	err = ioutil.WriteFile(sessionPath, []byte(s.SID), 0666)
+	if err != nil {
+		log.Println(errors.Wrap(err, "could not cache session id"))
+	}
+	return s, nil
+}

go.mod

@@ -0,0 +1,9 @@
+module git.marceltransier.de/lsf
+
+go 1.13
+
+require (
+	github.com/PuerkitoBio/goquery v1.5.0
+	github.com/pkg/errors v0.8.1
+	golang.org/x/crypto v0.0.0-20191002192127-34f69633bfdc
+)

go.sum

@@ -0,0 +1,18 @@
+github.com/PuerkitoBio/goquery v1.5.0 h1:uGvmFXOA73IKluu/F84Xd1tt/z07GYm8X49XKHP7EJk=
+github.com/PuerkitoBio/goquery v1.5.0/go.mod h1:qD2PgZ9lccMbQlc7eEOjaeRlFQON7xY8kdmcsrnKqMg=
+github.com/andybalholm/cascadia v1.0.0 h1:hOCXnnZ5A+3eVDX8pvgl4kofXv2ELss0bKcqRySc45o=
+github.com/andybalholm/cascadia v1.0.0/go.mod h1:GsXiBklL0woXo1j/WYWtSYYC4ouU9PqHO0sqidkEA4Y=
+github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
+github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20191002192127-34f69633bfdc h1:c0o/qxkaO2LF5t6fQrT4b5hzyggAkLLlCUjqfRxd8Q4=
+golang.org/x/crypto v0.0.0-20191002192127-34f69633bfdc/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/net v0.0.0-20180218175443-cbe0f9307d01/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20181114220301-adae6a3d119a h1:gOpx8G595UYyvj8UK4+OFyY4rx037g3fmfhe5SasG3U=
+golang.org/x/net v0.0.0-20181114220301-adae6a3d119a/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3 h1:0GoQqolDA55aaLxZyTzK/Y2ePZzZTUrRacwib7cNsYQ=
+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 h1:+R4KGOnez64A81RvjARKc4UT5/tI9ujCIVX+P5KiHuI=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

module.go

@@ -0,0 +1,5 @@
+package lsf
+
+type Modul struct {
+	Nr int
+}

noten.go

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+package lsf
+
+import (
+	"github.com/pkg/errors"
+	//"github.com/PuerkitoBio/goquery"
+)
+
+func (s *Session) Noten() (map[Modul]float32, error) {
+	return nil, errors.New("noten not implemented yet")
+}

session.go

@@ -0,0 +1,75 @@
+package lsf
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"strings"
+
+	"github.com/pkg/errors"
+)
+
+type Session struct {
+	SID string
+}
+
+func (s *Session) Valid() (bool, error) {
+	client := &http.Client{}
+	req, err := http.NewRequest("GET", "https://lsf.hs-worms.de/qisserver/rds?state=user&type=8&topitem=functions&breadCrumbSource=portal", nil)
+	if err != nil {
+		return false, errors.Wrap(err, "could not prepare the request")
+	}
+	req.Header.Add("Cookie", fmt.Sprintf("JSESSIONID=%s", s.SID))
+	resp, err := client.Do(req)
+	if err != nil {
+		return false, errors.Wrap(err, "could not do the request")
+	}
+	b, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return false, errors.Wrap(err, "could not read the response body")
+	}
+
+	if strings.Contains(string(b), "<u>L</u>ogout") {
+		return true, nil
+	}
+	if strings.Contains(string(b), "<u>L</u>ogin") {
+		return false, nil
+	}
+	return false, errors.New("unexpected response body")
+}
+
+func Login(username, password string) (*Session, error) {
+	client := &http.Client{
+		CheckRedirect: func(req *http.Request, via []*http.Request) error { // don't follow redirects
+			return http.ErrUseLastResponse
+		},
+	}
+	form := url.Values{}
+	form.Add("asdf", username) // who wrote this backend? lol
+	form.Add("fdsa", password)
+	form.Add("submit", "Login")
+	req, err := http.NewRequest("POST", "https://lsf.hs-worms.de/qisserver/rds?state=user&type=1&category=auth.login&startpage=portal.vm&breadCrumbSource=portal", strings.NewReader(form.Encode()))
+	req.Header.Add("Content-Type", "application/x-www-form-urlencoded")
+	if err != nil {
+		return nil, errors.Wrap(err, "could not prepare the login request")
+	}
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not do the login request")
+	}
+	if resp.StatusCode == 302 {
+		for _, c := range resp.Cookies() {
+			if c.Name == "JSESSIONID" {
+				return &Session{
+					SID: c.Value,
+				}, nil
+			}
+		}
+		return nil, errors.New("no session cookie found")
+	}
+	if resp.StatusCode == 200 {
+		return nil, errors.New("wrong credentials") // TODO or other errors
+	}
+	return nil, errors.New("unexpected response status code")
+}