lewis.moe
Monorepo for Tangled
guard,knotserver/internal: move guard logic to internal server
This will allow running guard without passing every single config
options
Signed-off-by: Seongmin Lee <git@boltless.me>
authored by
Seongmin Lee
and committed by
Tangled
d9e6028d
a99db81f
+36
-67
guard/guard.go
+36
-67
guard/guard.go
···
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12
"os/exec"
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"strings"
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14
15
-
"github.com/bluesky-social/indigo/atproto/identity"
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securejoin "github.com/cyphar/filepath-securejoin"
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"github.com/urfave/cli/v3"
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"tangled.org/core/idresolver"
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"tangled.org/core/knotserver/config"
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"tangled.org/core/log"
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)
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···
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func Run(ctx context.Context, cmd *cli.Command) error {
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l := log.FromContext(ctx)
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c, err := config.Load(ctx)
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if err != nil {
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return fmt.Errorf("failed to load config: %w", err)
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}
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-
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incomingUser := cmd.String("user")
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gitDir := cmd.String("git-dir")
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logPath := cmd.String("log-path")
···
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"command", sshCommand,
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"client", clientIP)
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// TODO: greet user with their resolved handle instead of did
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if sshCommand == "" {
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l.Info("access denied: no interactive shells", "user", incomingUser)
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fmt.Fprintf(os.Stderr, "Hi @%s! You've successfully authenticated.\n", incomingUser)
···
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}
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gitCommand := cmdParts[0]
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-
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// did:foo/repo-name or
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// handle/repo-name or
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// any of the above with a leading slash (/)
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-
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components := strings.Split(strings.TrimPrefix(strings.Trim(cmdParts[1], "'"), "/"), "/")
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l.Info("command components", "components", components)
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-
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if len(components) != 2 {
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l.Error("invalid repo format", "components", components)
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fmt.Fprintln(os.Stderr, "invalid repo format, needs <user>/<repo> or /<user>/<repo>")
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os.Exit(-1)
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}
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-
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didOrHandle := components[0]
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identity := resolveIdentity(ctx, c, l, didOrHandle)
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did := identity.DID.String()
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repoName := components[1]
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qualifiedRepoName, _ := securejoin.SecureJoin(did, repoName)
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repoPath := cmdParts[1]
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validCommands := map[string]bool{
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"git-receive-pack": true,
···
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return fmt.Errorf("access denied: invalid git command")
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}
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if gitCommand != "git-upload-pack" {
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if !isPushPermitted(l, incomingUser, qualifiedRepoName, endpoint) {
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l.Error("access denied: user not allowed",
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"did", incomingUser,
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"reponame", qualifiedRepoName)
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fmt.Fprintln(os.Stderr, "access denied: user not allowed")
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os.Exit(-1)
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}
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// qualify repo path from internal server which holds the knot config
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qualifiedRepoPath, err := guardAndQualifyRepo(l, endpoint, incomingUser, repoPath, gitCommand)
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if err != nil {
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l.Error("failed to run guard", "err", err)
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fmt.Fprintln(os.Stderr, err)
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os.Exit(1)
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}
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fullPath, _ := securejoin.SecureJoin(gitDir, qualifiedRepoName)
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fullPath, _ := securejoin.SecureJoin(gitDir, qualifiedRepoPath)
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l.Info("processing command",
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"user", incomingUser,
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"command", gitCommand,
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"repo", repoName,
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"repo", repoPath,
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"fullPath", fullPath,
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"client", clientIP)
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···
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gitCmd.Stdin = os.Stdin
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gitCmd.Env = append(os.Environ(),
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fmt.Sprintf("GIT_USER_DID=%s", incomingUser),
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fmt.Sprintf("GIT_USER_PDS_ENDPOINT=%s", identity.PDSEndpoint()),
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)
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if err := gitCmd.Run(); err != nil {
···
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l.Info("command completed",
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"user", incomingUser,
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"command", gitCommand,
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-
"repo", repoName,
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"repo", repoPath,
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"success", true)
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return nil
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}
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func resolveIdentity(ctx context.Context, c *config.Config, l *slog.Logger, didOrHandle string) *identity.Identity {
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resolver := idresolver.DefaultResolver(c.Server.PlcUrl)
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ident, err := resolver.ResolveIdent(ctx, didOrHandle)
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// runs guardAndQualifyRepo logic
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func guardAndQualifyRepo(l *slog.Logger, endpoint, incomingUser, repo, gitCommand string) (string, error) {
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u, _ := url.Parse(endpoint + "/guard")
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q := u.Query()
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q.Add("user", incomingUser)
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q.Add("repo", repo)
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q.Add("gitCmd", gitCommand)
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u.RawQuery = q.Encode()
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resp, err := http.Get(u.String())
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if err != nil {
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l.Error("Error resolving handle", "error", err, "handle", didOrHandle)
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fmt.Fprintf(os.Stderr, "error resolving handle: %v\n", err)
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os.Exit(1)
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return "", err
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}
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if ident.Handle.IsInvalidHandle() {
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l.Error("Error resolving handle", "invalid handle", didOrHandle)
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fmt.Fprintf(os.Stderr, "error resolving handle: invalid handle\n")
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os.Exit(1)
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}
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return ident
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}
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defer resp.Body.Close()
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func isPushPermitted(l *slog.Logger, user, qualifiedRepoName, endpoint string) bool {
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u, _ := url.Parse(endpoint + "/push-allowed")
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q := u.Query()
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q.Add("user", user)
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q.Add("repo", qualifiedRepoName)
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u.RawQuery = q.Encode()
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l.Info("Running guard", "url", u.String(), "status", resp.Status)
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req, err := http.Get(u.String())
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body, err := io.ReadAll(resp.Body)
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if err != nil {
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l.Error("Error verifying permissions", "error", err)
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fmt.Fprintf(os.Stderr, "error verifying permissions: %v\n", err)
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os.Exit(1)
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return "", err
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}
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text := string(body)
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l.Info("Checking push permission",
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"url", u.String(),
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"status", req.Status)
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return req.StatusCode == http.StatusNoContent
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switch resp.StatusCode {
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case http.StatusOK:
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return text, nil
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case http.StatusForbidden:
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l.Error("access denied: user not allowed", "did", incomingUser, "reponame", text)
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return text, errors.New("access denied: user not allowed")
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default:
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return "", errors.New(text)
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+
}
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}
+61
knotserver/internal.go
+61
knotserver/internal.go
···
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writeJSON(w, data)
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}
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// response in text/plain format
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// the body will be qualified repository path on success/push-denied
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// or an error message when process failed
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func (h *InternalHandle) Guard(w http.ResponseWriter, r *http.Request) {
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l := h.l.With("handler", "PostReceiveHook")
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+
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var (
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incomingUser = r.URL.Query().Get("user")
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repo = r.URL.Query().Get("repo")
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gitCommand = r.URL.Query().Get("gitCmd")
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)
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if incomingUser == "" || repo == "" || gitCommand == "" {
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w.WriteHeader(http.StatusBadRequest)
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l.Error("invalid request", "incomingUser", incomingUser, "repo", repo, "gitCommand", gitCommand)
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fmt.Fprintln(w, "invalid internal request")
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return
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}
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+
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// did:foo/repo-name or
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// handle/repo-name or
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// any of the above with a leading slash (/)
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components := strings.Split(strings.TrimPrefix(strings.Trim(repo, "'"), "/"), "/")
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l.Info("command components", "components", components)
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+
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if len(components) != 2 {
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w.WriteHeader(http.StatusBadRequest)
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l.Error("invalid repo format", "components", components)
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fmt.Fprintln(w, "invalid repo format, needs <user>/<repo> or /<user>/<repo>")
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return
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}
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repoOwner := components[0]
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repoName := components[1]
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+
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resolver := idresolver.DefaultResolver(h.c.Server.PlcUrl)
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repoOwnerIdent, err := resolver.ResolveIdent(r.Context(), repoOwner)
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if err != nil || repoOwnerIdent.Handle.IsInvalidHandle() {
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l.Error("Error resolving handle", "handle", repoOwner, "err", err)
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w.WriteHeader(http.StatusInternalServerError)
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fmt.Fprintf(w, "error resolving handle: invalid handle\n")
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return
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}
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repoOwnerDid := repoOwnerIdent.DID.String()
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+
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qualifiedRepo, _ := securejoin.SecureJoin(repoOwnerDid, repoName)
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+
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if gitCommand == "git-receive-pack" {
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ok, err := h.e.IsPushAllowed(incomingUser, rbac.ThisServer, qualifiedRepo)
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if err != nil || !ok {
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w.WriteHeader(http.StatusForbidden)
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fmt.Fprint(w, repo)
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return
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+
}
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+
}
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+
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w.WriteHeader(http.StatusOK)
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fmt.Fprint(w, qualifiedRepo)
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+
}
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+
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type PushOptions struct {
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skipCi bool
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verboseCi bool
···
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367
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r.Get("/push-allowed", h.PushAllowed)
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r.Get("/keys", h.InternalKeys)
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+
r.Get("/guard", h.Guard)
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r.Post("/hooks/post-receive", h.PostReceiveHook)
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r.Mount("/debug", middleware.Profiler())
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