Files
gitea-mcp/cmd/gitea-mcp/main.go
Mathias 3795800461
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fix(auth): require Bearer on /mcp regardless of DefaultToken
Previously BearerMiddleware allowed requests with no Authorization
header to pass through whenever GITEA_MCP_DEFAULT_TOKEN was set. The
intent was "fall back to the service PAT for upstream Gitea calls,"
but the side effect was that anyone could hit /mcp anonymously and the
server would happily proxy requests as the service account.

Drop that path. Auth on /mcp now requires either:
  - a valid Dex-issued JWT, or
  - a Bearer matching GITEA_MCP_STATIC_TOKEN.

The Gitea service PAT (GITEA_MCP_DEFAULT_TOKEN) is no longer wired
into BearerMiddleware at all — it stays an upstream-client concern,
used by gitea.NewClient for outbound API calls only. This decouples
"can this caller invoke a tool" from "what credentials does the tool
use against Gitea".

Tests updated: drop the NoAuthHeader_WithDefault permissive case, add
NoAuthHeader_RejectsEvenWhenStaticConfigured to lock in the new
behavior.

Closes part of mathias/infra#2.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-12 14:44:38 +02:00

102 lines
3.6 KiB
Go

package main
import (
"context"
"encoding/json"
"log/slog"
"net/http"
"os"
"gitea.d-ma.be/mathias/gitea-mcp/internal/allowlist"
"gitea.d-ma.be/mathias/gitea-mcp/internal/auth"
"gitea.d-ma.be/mathias/gitea-mcp/internal/config"
"gitea.d-ma.be/mathias/gitea-mcp/internal/gitea"
"gitea.d-ma.be/mathias/gitea-mcp/internal/mcp"
"gitea.d-ma.be/mathias/gitea-mcp/internal/registry"
"gitea.d-ma.be/mathias/gitea-mcp/internal/tools"
)
func main() {
logger := slog.New(slog.NewJSONHandler(os.Stdout, nil))
cfg, err := config.Load()
if err != nil {
logger.Error("load config", "err", err)
os.Exit(1)
}
ctx := context.Background()
jwtValidator, err := auth.NewJWTValidator(ctx, cfg.DexIssuerURL, cfg.MCPAudience)
if err != nil {
logger.Warn("jwt validator init failed; JWT auth disabled", "err", err)
}
giteaClient := gitea.NewClient(cfg.GiteaBaseURL, cfg.DefaultToken)
ownerAllow := allowlist.New(cfg.AllowedOwners)
reg := registry.New()
reg.Register(tools.NewRepoList(giteaClient, ownerAllow))
reg.Register(tools.NewRepoGet(giteaClient, ownerAllow))
reg.Register(tools.NewRepoSearch(giteaClient, ownerAllow))
reg.Register(tools.NewRepoStatus(giteaClient, ownerAllow))
reg.Register(tools.NewFileRead(giteaClient, ownerAllow))
reg.Register(tools.NewFileWriteBranch(giteaClient, ownerAllow))
reg.Register(tools.NewFileDelete(giteaClient, ownerAllow))
reg.Register(tools.NewDirList(giteaClient, ownerAllow))
reg.Register(tools.NewBranchList(giteaClient, ownerAllow))
reg.Register(tools.NewBranchDelete(giteaClient, ownerAllow))
reg.Register(tools.NewBranchProtectionGet(giteaClient, ownerAllow))
reg.Register(tools.NewPRCreate(giteaClient, ownerAllow))
reg.Register(tools.NewPRGet(giteaClient, ownerAllow))
reg.Register(tools.NewPRList(giteaClient, ownerAllow))
reg.Register(tools.NewPRMerge(giteaClient, ownerAllow))
reg.Register(tools.NewPRComment(giteaClient, ownerAllow))
reg.Register(tools.NewPRFilesDiff(giteaClient, ownerAllow))
reg.Register(tools.NewWorkflowRunTrigger(giteaClient, ownerAllow, cfg.GiteaBaseURL))
reg.Register(tools.NewWorkflowRunStatus(giteaClient, ownerAllow))
reg.Register(tools.NewCodeSearch(giteaClient, ownerAllow))
reg.Register(tools.NewIssueCreate(giteaClient, ownerAllow))
reg.Register(tools.NewIssueComment(giteaClient, ownerAllow))
reg.Register(tools.NewCreateProjectFromTemplate(giteaClient, ownerAllow, "mathias", "template-go-web"))
reg.Register(tools.NewTagCreate(giteaClient, ownerAllow))
mcpSrv := mcp.NewServer(mcp.ServerOptions{
Registry: reg,
Sessions: mcp.NewSessionStore(),
})
mux := http.NewServeMux()
mux.Handle("/mcp", mcp.OriginAllowlist(cfg.OriginAllowlist)(
auth.BearerMiddleware(jwtValidator, cfg.StaticToken,
auth.CallerMiddleware(mcpSrv),
),
))
mux.HandleFunc("/healthz", func(w http.ResponseWriter, _ *http.Request) {
w.WriteHeader(http.StatusOK)
_, _ = w.Write([]byte("ok"))
})
mux.HandleFunc("/.well-known/oauth-protected-resource", func(w http.ResponseWriter, r *http.Request) {
if r.Method != http.MethodGet {
http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
return
}
w.Header().Set("Content-Type", "application/json")
payload := map[string]any{
"resource": cfg.MCPResourceURL,
"authorization_servers": []string{},
}
if cfg.DexIssuerURL != "" {
payload["authorization_servers"] = []string{cfg.DexIssuerURL}
}
_ = json.NewEncoder(w).Encode(payload)
})
addr := ":" + cfg.Port
logger.Info("gitea-mcp starting", "addr", addr, "version", "0.1.0")
if err := http.ListenAndServe(addr, mux); err != nil {
logger.Error("server stopped", "err", err)
os.Exit(1)
}
}