package github
import (
"bufio"
"bytes"
"encoding/json"
"fmt"
"io"
"io/ioutil"
"math/rand"
"net/http"
"os"
"regexp"
"sort"
"strconv"
"strings"
"syscall"
"time"
text "github.com/MichaelMure/go-term-text"
"github.com/pkg/errors"
"golang.org/x/crypto/ssh/terminal"
"github.com/MichaelMure/git-bug/bridge/core"
"github.com/MichaelMure/git-bug/bridge/core/auth"
"github.com/MichaelMure/git-bug/cache"
"github.com/MichaelMure/git-bug/entity"
"github.com/MichaelMure/git-bug/identity"
"github.com/MichaelMure/git-bug/repository"
"github.com/MichaelMure/git-bug/util/colors"
"github.com/MichaelMure/git-bug/util/interrupt"
)
const (
target = "github"
githubV3Url = "https://api.github.com"
keyOwner = "owner"
keyProject = "project"
defaultTimeout = 60 * time.Second
)
var (
ErrBadProjectURL = errors.New("bad project url")
)
func (g *Github) Configure(repo *cache.RepoCache, params core.BridgeParams) (core.Configuration, error) {
if params.BaseURL != "" {
fmt.Println("warning: --base-url is ineffective for a Github bridge")
}
conf := make(core.Configuration)
var err error
if (params.CredPrefix != "" || params.TokenRaw != "") &&
(params.URL == "" && (params.Project == "" || params.Owner == "")) {
return nil, fmt.Errorf("you must provide a project URL or Owner/Name to configure this bridge with a token")
}
var owner string
var project string
// getting owner and project name
switch {
case params.Owner != "" && params.Project != "":
// first try to use params if both or project and owner are provided
owner = params.Owner
project = params.Project
case params.URL != "":
// try to parse params URL and extract owner and project
owner, project, err = splitURL(params.URL)
if err != nil {
return nil, err
}
default:
// terminal prompt
owner, project, err = promptURL(repo)
if err != nil {
return nil, err
}
}
// validate project owner
ok, err := validateUsername(owner)
if err != nil {
return nil, err
}
if !ok {
return nil, fmt.Errorf("invalid parameter owner: %v", owner)
}
user, err := repo.GetUserIdentity()
if err != nil && err != identity.ErrNoIdentitySet {
return nil, err
}
// default to a "to be filled" user Id if we don't have a valid one yet
userId := auth.DefaultUserId
if user != nil {
userId = user.Id()
}
var cred auth.Credential
switch {
case params.CredPrefix != "":
cred, err = auth.LoadWithPrefix(repo, params.CredPrefix)
if err != nil {
return nil, err
}
if user != nil && cred.UserId() != user.Id() {
return nil, fmt.Errorf("selected credential don't match the user")
}
case params.TokenRaw != "":
cred = auth.NewToken(userId, params.TokenRaw, target)
default:
cred, err = promptTokenOptions(repo, userId, owner, project)
if err != nil {
return nil, err
}
}
token, ok := cred.(*auth.Token)
if !ok {
return nil, fmt.Errorf("the Github bridge only handle token credentials")
}
// verify access to the repository with token
ok, err = validateProject(owner, project, token)
if err != nil {
return nil, err
}
if !ok {
return nil, fmt.Errorf("project doesn't exist or authentication token has an incorrect scope")
}
conf[core.ConfigKeyTarget] = target
conf[keyOwner] = owner
conf[keyProject] = project
err = g.ValidateConfig(conf)
if err != nil {
return nil, err
}
// don't forget to store the now known valid token
if !auth.IdExist(repo, cred.ID()) {
err = auth.Store(repo, cred)
if err != nil {
return nil, err
}
}
return conf, nil
}
func (*Github) ValidateConfig(conf core.Configuration) error {
if v, ok := conf[core.ConfigKeyTarget]; !ok {
return fmt.Errorf("missing %s key", core.ConfigKeyTarget)
} else if v != target {
return fmt.Errorf("unexpected target name: %v", v)
}
if _, ok := conf[keyOwner]; !ok {
return fmt.Errorf("missing %s key", keyOwner)
}
if _, ok := conf[keyProject]; !ok {
return fmt.Errorf("missing %s key", keyProject)
}
return nil
}
func requestToken(note, username, password string, scope string) (*http.Response, error) {
return requestTokenWith2FA(note, username, password, "", scope)
}
func requestTokenWith2FA(note, username, password, otpCode string, scope string) (*http.Response, error) {
url := fmt.Sprintf("%s/authorizations", githubV3Url)
params := struct {
Scopes []string `json:"scopes"`
Note string `json:"note"`
Fingerprint string `json:"fingerprint"`
}{
Scopes: []string{scope},
Note: note,
Fingerprint: randomFingerprint(),
}
data, err := json.Marshal(params)
if err != nil {
return nil, err
}
req, err := http.NewRequest("POST", url, bytes.NewBuffer(data))
if err != nil {
return nil, err
}
req.SetBasicAuth(username, password)
req.Header.Set("Content-Type", "application/json")
if otpCode != "" {
req.Header.Set("X-GitHub-OTP", otpCode)
}
client := &http.Client{
Timeout: defaultTimeout,
}
return client.Do(req)
}
func decodeBody(body io.ReadCloser) (string, error) {
data, _ := ioutil.ReadAll(body)
aux := struct {
Token string `json:"token"`
}{}
err := json.Unmarshal(data, &aux)
if err != nil {
return "", err
}
if aux.Token == "" {
return "", fmt.Errorf("no token found in response: %s", string(data))
}
return aux.Token, nil
}
func randomFingerprint() string {
// Doesn't have to be crypto secure, it's just to avoid token collision
rand.Seed(time.Now().UnixNano())
var letterRunes = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
b := make([]rune, 32)
for i := range b {
b[i] = letterRunes[rand.Intn(len(letterRunes))]
}
return string(b)
}
func promptTokenOptions(repo repository.RepoConfig, userId entity.Id, owner, project string) (auth.Credential, error) {
for {
creds, err := auth.List(repo, auth.WithUserId(userId), auth.WithTarget(target))
if err != nil {
return nil, err
}
fmt.Println()
fmt.Println("[1]: enter my token")
fmt.Println("[2]: interactive token creation")
if len(creds) > 0 {
sort.Sort(auth.ById(creds))
fmt.Println()
fmt.Println("Existing tokens for Github:")
for i, cred := range creds {
token := cred.(*auth.Token)
fmt.Printf("[%d]: %s => %s (%s)\n",
i+3,
colors.Cyan(token.ID().Human()),
colors.Red(text.TruncateMax(token.Value, 10)),
token.CreateTime().Format(time.RFC822),
)
}
}
fmt.Println()
fmt.Print("Select option: ")
line, err := bufio.NewReader(os.Stdin).ReadString('\n')
fmt.Println()
if err != nil {
return nil, err
}
line = strings.TrimSpace(line)
index, err := strconv.Atoi(line)
if err != nil || index < 1 || index > len(creds)+2 {
fmt.Println("invalid input")
continue
}
switch index {
case 1:
value, err := promptToken()
if err != nil {
return nil, err
}
return auth.NewToken(userId, value, target), nil
case 2:
value, err := loginAndRequestToken(owner, project)
if err != nil {
return nil, err
}
return auth.NewToken(userId, value, target), nil
default:
return creds[index-3], nil
}
}
}
func promptToken() (string, error) {
fmt.Println("You can generate a new token by visiting https://github.com/settings/tokens.")
fmt.Println("Choose 'Generate new token' and set the necessary access scope for your repository.")
fmt.Println()
fmt.Println("The access scope depend on the type of repository.")
fmt.Println("Public:")
fmt.Println(" - 'public_repo': to be able to read public repositories")
fmt.Println("Private:")
fmt.Println(" - 'repo' : to be able to read private repositories")
fmt.Println()
re, err := regexp.Compile(`^[a-zA-Z0-9]{40}`)
if err != nil {
panic("regexp compile:" + err.Error())
}
for {
fmt.Print("Enter token: ")
line, err := bufio.NewReader(os.Stdin).ReadString('\n')
if err != nil {
return "", err
}
token := strings.TrimSpace(line)
if re.MatchString(token) {
return token, nil
}
fmt.Println("token has incorrect format")
}
}
func loginAndRequestToken(owner, project string) (string, error) {
fmt.Println("git-bug will now generate an access token in your Github profile. Your credential are not stored and are only used to generate the token. The token is stored in the global git config.")
fmt.Println()
fmt.Println("The access scope depend on the type of repository.")
fmt.Println("Public:")
fmt.Println(" - 'public_repo': to be able to read public repositories")
fmt.Println("Private:")
fmt.Println(" - 'repo' : to be able to read private repositories")
fmt.Println()
// prompt project visibility to know the token scope needed for the repository
isPublic, err := promptProjectVisibility()
if err != nil {
return "", err
}
username, err := promptUsername()
if err != nil {
return "", err
}
password, err := promptPassword()
if err != nil {
return "", err
}
var scope string
if isPublic {
// public_repo is requested to be able to read public repositories
scope = "public_repo"
} else {
// 'repo' is request to be able to read private repositories
// /!\ token will have read/write rights on every private repository you have access to
scope = "repo"
}
// Attempt to authenticate and create a token
note := fmt.Sprintf("git-bug - %s/%s", owner, project)
resp, err := requestToken(note, username, password, scope)
if err != nil {
return "", err
}
defer resp.Body.Close()
// Handle 2FA is needed
OTPHeader := resp.Header.Get("X-GitHub-OTP")
if resp.StatusCode == http.StatusUnauthorized && OTPHeader != "" {
otpCode, err := prompt2FA()
if err != nil {
return "", err
}
resp, err = requestTokenWith2FA(note, username, password, otpCode, scope)
if err != nil {
return "", err
}
defer resp.Body.Close()
}
if resp.StatusCode == http.StatusCreated {
return decodeBody(resp.Body)
}
b, _ := ioutil.ReadAll(resp.Body)
return "", fmt.Errorf("error creating token %v: %v", resp.StatusCode, string(b))
}
func promptUsername() (string, error) {
for {
fmt.Print("username: ")
line, err := bufio.NewReader(os.Stdin).ReadString('\n')
if err != nil {
return "", err
}
line = strings.TrimSpace(line)
ok, err := validateUsername(line)
if err != nil {
return "", err
}
if ok {
return line, nil
}
fmt.Println("invalid username")
}
}
func promptURL(repo repository.RepoCommon) (string, string, error) {
// remote suggestions
remotes, err := repo.GetRemotes()
if err != nil {
return "", "", err
}
validRemotes := getValidGithubRemoteURLs(remotes)
if len(validRemotes) > 0 {
for {
fmt.Println("\nDetected projects:")
// print valid remote github urls
for i, remote := range validRemotes {
fmt.Printf("[%d]: %v\n", i+1, remote)
}
fmt.Printf("\n[0]: Another project\n\n")
fmt.Printf("Select option: ")
line, err := bufio.NewReader(os.Stdin).ReadString('\n')
if err != nil {
return "", "", err
}
line = strings.TrimSpace(line)
index, err := strconv.Atoi(line)
if err != nil || index < 0 || index > len(validRemotes) {
fmt.Println("invalid input")
continue
}
// if user want to enter another project url break this loop
if index == 0 {
break
}
// get owner and project with index
owner, project, _ := splitURL(validRemotes[index-1])
return owner, project, nil
}
}
// manually enter github url
for {
fmt.Print("Github project URL: ")
line, err := bufio.NewReader(os.Stdin).ReadString('\n')
if err != nil {
return "", "", err
}
line = strings.TrimSpace(line)
if line == "" {
fmt.Println("URL is empty")
continue
}
// get owner and project from url
owner, project, err := splitURL(line)
if err != nil {
fmt.Println(err)
continue
}
return owner, project, nil
}
}
// splitURL extract the owner and project from a github repository URL. It will remove the
// '.git' extension from the URL before parsing it.
// Note that Github removes the '.git' extension from projects names at their creation
func splitURL(url string) (owner string, project string, err error) {
cleanURL := strings.TrimSuffix(url, ".git")
re, err := regexp.Compile(`github\.com[/:]([a-zA-Z0-9\-_]+)/([a-zA-Z0-9\-_.]+)`)
if err != nil {
panic("regexp compile:" + err.Error())
}
res := re.FindStringSubmatch(cleanURL)
if res == nil {
return "", "", ErrBadProjectURL
}
owner = res[1]
project = res[2]
return
}
func getValidGithubRemoteURLs(remotes map[string]string) []string {
urls := make([]string, 0, len(remotes))
for _, url := range remotes {
// split url can work again with shortURL
owner, project, err := splitURL(url)
if err == nil {
shortURL := fmt.Sprintf("%s/%s/%s", "github.com", owner, project)
urls = append(urls, shortURL)
}
}
sort.Strings(urls)
return urls
}
func validateUsername(username string) (bool, error) {
url := fmt.Sprintf("%s/users/%s", githubV3Url, username)
client := &http.Client{
Timeout: defaultTimeout,
}
resp, err := client.Get(url)
if err != nil {
return false, err
}
err = resp.Body.Close()
if err != nil {
return false, err
}
return resp.StatusCode == http.StatusOK, nil
}
func validateProject(owner, project string, token *auth.Token) (bool, error) {
url := fmt.Sprintf("%s/repos/%s/%s", githubV3Url, owner, project)
req, err := http.NewRequest("GET", url, nil)
if err != nil {
return false, err
}
// need the token for private repositories
req.Header.Set("Authorization", fmt.Sprintf("token %s", token.Value))
client := &http.Client{
Timeout: defaultTimeout,
}
resp, err := client.Do(req)
if err != nil {
return false, err
}
err = resp.Body.Close()
if err != nil {
return false, err
}
return resp.StatusCode == http.StatusOK, nil
}
func promptPassword() (string, error) {
termState, err := terminal.GetState(int(syscall.Stdin))
if err != nil {
return "", err
}
cancel := interrupt.RegisterCleaner(func() error {
return terminal.Restore(int(syscall.Stdin), termState)
})
defer cancel()
for {
fmt.Print("password: ")
bytePassword, err := terminal.ReadPassword(int(syscall.Stdin))
// new line for coherent formatting, ReadPassword clip the normal new line
// entered by the user
fmt.Println()
if err != nil {
return "", err
}
if len(bytePassword) > 0 {
return string(bytePassword), nil
}
fmt.Println("password is empty")
}
}
func prompt2FA() (string, error) {
termState, err := terminal.GetState(int(syscall.Stdin))
if err != nil {
return "", err
}
cancel := interrupt.RegisterCleaner(func() error {
return terminal.Restore(int(syscall.Stdin), termState)
})
defer cancel()
for {
fmt.Print("two-factor authentication code: ")
byte2fa, err := terminal.ReadPassword(int(syscall.Stdin))
fmt.Println()
if err != nil {
return "", err
}
if len(byte2fa) > 0 {
return string(byte2fa), nil
}
fmt.Println("code is empty")
}
}
func promptProjectVisibility() (bool, error) {
for {
fmt.Println("[1]: public")
fmt.Println("[2]: private")
fmt.Print("repository visibility: ")
line, err := bufio.NewReader(os.Stdin).ReadString('\n')
fmt.Println()
if err != nil {
return false, err
}
line = strings.TrimSpace(line)
index, err := strconv.Atoi(line)
if err != nil || (index != 1 && index != 2) {
fmt.Println("invalid input")
continue
}
// return true for public repositories, false for private
return index == 1, nil
}
}
