1 files changed, 282 insertions, 0 deletions
diff --git a/bridge/github/config.go b/bridge/github/config.go
new file mode 100644
index 00000000..3b12d3f9
--- /dev/null
+++ b/bridge/github/config.go
@@ -0,0 +1,282 @@
+package github
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"math/rand"
+	"net/http"
+	"os"
+	"regexp"
+	"strings"
+	"syscall"
+	"time"
+
+	"github.com/MichaelMure/git-bug/bridge/core"
+	"github.com/MichaelMure/git-bug/repository"
+	"golang.org/x/crypto/ssh/terminal"
+)
+
+const githubV3Url = "https://api.Github.com"
+const keyUser = "user"
+const keyProject = "project"
+const keyToken = "token"
+
+func (*Github) Configure(repo repository.RepoCommon) (core.Configuration, error) {
+	conf := make(core.Configuration)
+
+	fmt.Println("git-bug will generate an access token in your Github profile.")
+	// fmt.Println("The token will have the \"repo\" permission, giving it read/write access to your repositories and issues. There is no narrower scope available, sorry :-|")
+	fmt.Println()
+
+	projectUser, projectName, err := promptURL()
+	if err != nil {
+		return nil, err
+	}
+
+	conf[keyUser] = projectUser
+	conf[keyProject] = projectName
+
+	fmt.Println()
+
+	username, err := promptUsername()
+	if err != nil {
+		return nil, err
+	}
+
+	fmt.Println()
+
+	password, err := promptPassword()
+	if err != nil {
+		return nil, err
+	}
+
+	fmt.Println()
+
+	// Attempt to authenticate and create a token
+
+	note := fmt.Sprintf("git-bug - %s/%s", projectUser, projectName)
+
+	resp, err := requestToken(note, username, password)
+	if err != nil {
+		return nil, 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 nil, err
+		}
+
+		resp, err = requestTokenWith2FA(note, username, password, otpCode)
+		if err != nil {
+			return nil, err
+		}
+
+		defer resp.Body.Close()
+	}
+
+	if resp.StatusCode == http.StatusCreated {
+		token, err := decodeBody(resp.Body)
+		if err != nil {
+			return nil, err
+		}
+		conf[keyToken] = token
+		return conf, nil
+	}
+
+	b, _ := ioutil.ReadAll(resp.Body)
+	fmt.Printf("Error %v: %v\n", resp.StatusCode, string(b))
+
+	return nil, nil
+}
+
+func requestToken(note, username, password string) (*http.Response, error) {
+	return requestTokenWith2FA(note, username, password, "")
+}
+
+func requestTokenWith2FA(note, username, password, otpCode 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{"repo"},
+		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{}
+
+	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 promptUsername() (string, error) {
+	for {
+		fmt.Println("username:")
+
+		line, err := bufio.NewReader(os.Stdin).ReadString('\n')
+		if err != nil {
+			return "", err
+		}
+
+		line = strings.TrimRight(line, "\n")
+
+		ok, err := validateUsername(line)
+		if err != nil {
+			return "", err
+		}
+		if ok {
+			return line, nil
+		}
+
+		fmt.Println("invalid username")
+	}
+}
+
+func promptURL() (string, string, error) {
+	for {
+		fmt.Println("Github project URL:")
+
+		line, err := bufio.NewReader(os.Stdin).ReadString('\n')
+		if err != nil {
+			return "", "", err
+		}
+
+		line = strings.TrimRight(line, "\n")
+
+		if line == "" {
+			fmt.Println("URL is empty")
+			continue
+		}
+
+		projectUser, projectName, err := splitURL(line)
+
+		if err != nil {
+			fmt.Println(err)
+			continue
+		}
+
+		return projectUser, projectName, nil
+	}
+}
+
+func splitURL(url string) (string, string, error) {
+	re, err := regexp.Compile(`github\.com\/([^\/]*)\/([^\/]*)`)
+	if err != nil {
+		return "", "", err
+	}
+
+	res := re.FindStringSubmatch(url)
+
+	if res == nil {
+		return "", "", fmt.Errorf("bad github project url")
+	}
+
+	return res[1], res[2], nil
+}
+
+func validateUsername(username string) (bool, error) {
+	url := fmt.Sprintf("%s/users/%s", githubV3Url, username)
+
+	resp, err := http.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 promptPassword() (string, error) {
+	for {
+		fmt.Println("password:")
+
+		bytePassword, err := terminal.ReadPassword(int(syscall.Stdin))
+		if err != nil {
+			return "", err
+		}
+
+		if len(bytePassword) > 0 {
+			return string(bytePassword), nil
+		}
+
+		fmt.Println("password is empty")
+	}
+}
+
+func prompt2FA() (string, error) {
+	for {
+		fmt.Println("two-factor authentication code:")
+
+		byte2fa, err := terminal.ReadPassword(int(syscall.Stdin))
+		if err != nil {
+			return "", err
+		}
+
+		if len(byte2fa) > 0 {
+			return string(byte2fa), nil
+		}
+
+		fmt.Println("code is empty")
+	}
+}