1 files changed, 100 insertions, 0 deletions
diff --git a/services/doctor/authorizedkeys.go b/services/doctor/authorizedkeys.go
new file mode 100644
index 0000000..2920cf5
--- /dev/null
+++ b/services/doctor/authorizedkeys.go
@@ -0,0 +1,100 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package doctor
+
+import (
+	"bufio"
+	"bytes"
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	asymkey_model "code.gitea.io/gitea/models/asymkey"
+	"code.gitea.io/gitea/modules/container"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+)
+
+const tplCommentPrefix = `# gitea public key`
+
+func checkAuthorizedKeys(ctx context.Context, logger log.Logger, autofix bool) error {
+	if setting.SSH.StartBuiltinServer || !setting.SSH.CreateAuthorizedKeysFile {
+		return nil
+	}
+
+	fPath := filepath.Join(setting.SSH.RootPath, "authorized_keys")
+	f, err := os.Open(fPath)
+	if err != nil {
+		if !autofix {
+			logger.Critical("Unable to open authorized_keys file. ERROR: %v", err)
+			return fmt.Errorf("Unable to open authorized_keys file. ERROR: %w", err)
+		}
+		logger.Warn("Unable to open authorized_keys. (ERROR: %v). Attempting to rewrite...", err)
+		if err = asymkey_model.RewriteAllPublicKeys(ctx); err != nil {
+			logger.Critical("Unable to rewrite authorized_keys file. ERROR: %v", err)
+			return fmt.Errorf("Unable to rewrite authorized_keys file. ERROR: %w", err)
+		}
+	}
+	defer f.Close()
+
+	linesInAuthorizedKeys := make(container.Set[string])
+
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		line := scanner.Text()
+		if strings.HasPrefix(line, tplCommentPrefix) {
+			continue
+		}
+		linesInAuthorizedKeys.Add(line)
+	}
+	if err = scanner.Err(); err != nil {
+		return fmt.Errorf("scan: %w", err)
+	}
+	// although there is a "defer close" above, here close explicitly before the generating, because it needs to open the file for writing again
+	_ = f.Close()
+
+	// now we regenerate and check if there are any lines missing
+	regenerated := &bytes.Buffer{}
+	if err := asymkey_model.RegeneratePublicKeys(ctx, regenerated); err != nil {
+		logger.Critical("Unable to regenerate authorized_keys file. ERROR: %v", err)
+		return fmt.Errorf("Unable to regenerate authorized_keys file. ERROR: %w", err)
+	}
+	scanner = bufio.NewScanner(regenerated)
+	for scanner.Scan() {
+		line := scanner.Text()
+		if strings.HasPrefix(line, tplCommentPrefix) {
+			continue
+		}
+		if linesInAuthorizedKeys.Contains(line) {
+			continue
+		}
+		if !autofix {
+			logger.Critical(
+				"authorized_keys file %q is out of date.\nRegenerate it with:\n\t\"%s\"\nor\n\t\"%s\"",
+				fPath,
+				"forgejo admin regenerate keys",
+				"forgejo doctor check --run authorized-keys --fix")
+			return fmt.Errorf(`authorized_keys is out of date and should be regenerated with "forgejo admin regenerate keys" or "forgejo doctor check --run authorized-keys --fix"`)
+		}
+		logger.Warn("authorized_keys is out of date. Attempting rewrite...")
+		err = asymkey_model.RewriteAllPublicKeys(ctx)
+		if err != nil {
+			logger.Critical("Unable to rewrite authorized_keys file. ERROR: %v", err)
+			return fmt.Errorf("Unable to rewrite authorized_keys file. ERROR: %w", err)
+		}
+	}
+	return nil
+}
+
+func init() {
+	Register(&Check{
+		Title:     "Check if OpenSSH authorized_keys file is up-to-date",
+		Name:      "authorized-keys",
+		IsDefault: true,
+		Run:       checkAuthorizedKeys,
+		Priority:  4,
+	})
+}