Introduce user repositories

gitlab.go

@@ -0,0 +1,163 @@
+package main
+
+import (
+	"context"
+	"encoding/hex"
+	"encoding/json"
+	"flag"
+	"log"
+	"net/http"
+	"os"
+
+	"golang.org/x/oauth2"
+
+	"github.com/coreos/go-oidc/v3/oidc"
+	"github.com/gin-gonic/gin"
+)
+
+const (
+	OAUTH_GITLAB_FILE = ".gitlab-oauth-token"
+)
+
+var (
+	gitlabBaseURL      = "https://gitlab.cri.epita.fr"
+	gitlabClientID     = ""
+	gitlabSecret       = ""
+	gitlaboauth2Config oauth2.Config
+	gitlaboidcVerifier *oidc.IDTokenVerifier
+	gitlabToken        *oauth2.Token
+)
+
+func init() {
+	flag.StringVar(&gitlabClientID, "gitlab-clientid", gitlabClientID, "ClientID for GitLab's OIDC")
+	flag.StringVar(&gitlabSecret, "gitlab-secret", gitlabSecret, "Secret for GitLab's OIDC")
+}
+
+func initializeGitLabOIDC(router *gin.Engine, authrouter *gin.RouterGroup, adminrouter *gin.RouterGroup) {
+	adminrouter.GET("/auth/gitlabcri", redirectOAuth_GitLab)
+	router.GET("/callback/gitlabcri/complete", GitLab_OAuth_complete)
+
+	if _, err := os.Stat(OAUTH_GITLAB_FILE); err == nil {
+		gitlabToken, err = loadOAuth2Token(OAUTH_GITLAB_FILE)
+		if err != nil {
+			log.Println("Unable to load OAuth2 Token:", err.Error())
+		}
+	}
+
+	if gitlabClientID != "" && gitlabSecret != "" {
+		provider, err := oidc.NewProvider(context.Background(), gitlabBaseURL)
+		if err != nil {
+			log.Fatal("Unable to setup oidc:", err)
+		}
+
+		gitlaboauth2Config = oauth2.Config{
+			ClientID:     gitlabClientID,
+			ClientSecret: gitlabSecret,
+			RedirectURL:  oidcRedirectURL + baseURL + "/callback/gitlabcri/complete",
+
+			// Discovery returns the OAuth2 endpoints.
+			Endpoint: provider.Endpoint(),
+
+			// "openid" is a required scope for OpenID Connect flows.
+			Scopes: []string{"api", "read_repository", "email"},
+		}
+
+		oidcConfig := oidc.Config{
+			ClientID: gitlabClientID,
+		}
+		gitlaboidcVerifier = provider.Verifier(&oidcConfig)
+
+		authrouter.GET("/api/gitlabcri/repositories", GitLab_getRepositories)
+	}
+}
+
+func loadOAuth2Token(file string) (*oauth2.Token, error) {
+	fd, err := os.Open(file)
+	if err != nil {
+		return nil, err
+	}
+	defer fd.Close()
+
+	var tok oauth2.Token
+	err = json.NewDecoder(fd).Decode(&tok)
+
+	return &tok, err
+}
+
+func saveOAuth2Token(file string, tok *oauth2.Token) error {
+	fd, err := os.Create(file)
+	if err != nil {
+		return err
+	}
+	defer fd.Close()
+
+	return json.NewEncoder(fd).Encode(tok)
+}
+
+func redirectOAuth_GitLab(c *gin.Context) {
+	session := c.MustGet("Session").(*Session)
+
+	// Save next parameter
+	if len(c.Request.URL.Query().Get("next")) > 0 {
+		session.SetKey("gitlab-oidc-source", c.Request.URL.Query().Get("next"))
+	}
+
+	c.Redirect(http.StatusFound, gitlaboauth2Config.AuthCodeURL(hex.EncodeToString(session.Id)))
+}
+
+func GitLab_OAuth_complete(c *gin.Context) {
+	idsession, err := hex.DecodeString(c.Request.URL.Query().Get("state"))
+	if err != nil {
+		c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"errmsg": err.Error()})
+		return
+	}
+
+	session, err := getSession(idsession)
+	if err != nil {
+		c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"errmsg": err.Error()})
+		return
+	}
+
+	oauth2Token, err := gitlaboauth2Config.Exchange(c.Request.Context(), c.Request.URL.Query().Get("code"))
+	if err != nil {
+		c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{"errmsg": "Failed to exchange token: " + err.Error()})
+		return
+	}
+
+	gitlabToken = oauth2Token
+	err = saveOAuth2Token(OAUTH_GITLAB_FILE, oauth2Token)
+	if err != nil {
+		c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{"errmsg": "Unable to save OAuth2 token: " + err.Error()})
+		return
+
+	}
+	log.Println("New GitLab OAuth2 session opened")
+
+	if source, ok := session.GetKey("gitlab-oidc-source"); ok {
+		session.DeleteKey("gitlab-oidc-source")
+		c.Redirect(http.StatusFound, baseURL+source.(string))
+	} else {
+		c.Redirect(http.StatusFound, baseURL+"/works")
+	}
+	session.Update()
+}
+
+func GitLab_getRepositories(c *gin.Context) {
+	client := gitlaboauth2Config.Client(c.Request.Context(), gitlabToken)
+
+	req, err := http.NewRequest("GET", gitlabBaseURL+"/api/v4/projects", nil)
+	if err != nil {
+		log.Println("Unable to create NewRequest before GitLab call: ", err.Error())
+		c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{"errmsg": "An error occurs when performing the GitLab request."})
+		return
+	}
+
+	resp, err := client.Do(req)
+	if err != nil {
+		log.Println("Unable to perform the GitLab request: ", err.Error())
+		c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{"errmsg": "An error occurs when performing the GitLab request."})
+		return
+	}
+
+	c.DataFromReader(resp.StatusCode, resp.ContentLength, resp.Header.Get("content-type"), resp.Body, nil)
+}