// Copyright 2022 The Gitea Authors. All rights reserved.// SPDX-License-Identifier: MIT package ssh import (	"context"	"fmt"	"net"	"os"	"path/filepath"	"strconv"	"strings" 	"forgejo.org/models/asymkey"	"forgejo.org/modules/log"	"forgejo.org/modules/setting") var logger = log.GetManager().GetLogger("ssh") func Init(ctx context.Context) error {	if setting.SSH.Disabled {		builtinUnused()		return nil	} 	if setting.SSH.StartBuiltinServer {		Listen(setting.SSH.ListenHost, setting.SSH.ListenPort, setting.SSH.ServerCiphers, setting.SSH.ServerKeyExchanges, setting.SSH.ServerMACs)		log.Info("SSH server started on %s. Cipher list (%v), key exchange algorithms (%v), MACs (%v)",			net.JoinHostPort(setting.SSH.ListenHost, strconv.Itoa(setting.SSH.ListenPort)),			setting.SSH.ServerCiphers, setting.SSH.ServerKeyExchanges, setting.SSH.ServerMACs,		)		return nil	} 	builtinUnused() 	// FIXME: why 0o644 for a directory .....	if err := os.MkdirAll(setting.SSH.KeyTestPath, 0o644); err != nil {		return fmt.Errorf("failed to create directory %q for ssh key test: %w", setting.SSH.KeyTestPath, err)	} 	if len(setting.SSH.TrustedUserCAKeys) > 0 && setting.SSH.AuthorizedPrincipalsEnabled {		caKeysFileName := setting.SSH.TrustedUserCAKeysFile		caKeysFileDir := filepath.Dir(caKeysFileName) 		err := os.MkdirAll(caKeysFileDir, 0o700) // SSH.RootPath by default (That is `~/.ssh` in most cases)		if err != nil {			return fmt.Errorf("failed to create directory %q for ssh trusted ca keys: %w", caKeysFileDir, err)		} 		if err := os.WriteFile(caKeysFileName, []byte(strings.Join(setting.SSH.TrustedUserCAKeys, "\n")), 0o600); err != nil {			return fmt.Errorf("failed to write ssh trusted ca keys to %q: %w", caKeysFileName, err)		}	} 	if !setting.SSH.AllowUnexpectedAuthorizedKeys {		findings, err := asymkey.InspectPublicKeys(ctx)		if err != nil {			return fmt.Errorf("inspect authorized_keys failed: %w", err)		} 		unexpectedKeys := []string{}		for _, finding := range findings {			switch finding.Type {			case asymkey.InspectionResultFileMissing:				err := asymkey.RewriteAllPublicKeys(ctx)				if err != nil {					return fmt.Errorf("rewrite authorized_keys failed: %w", err)				}			case asymkey.InspectionResultUnexpectedKey:				unexpectedKeys = append(unexpectedKeys, finding.Comment) 			case asymkey.InspectionResultMissingExpectedKey:				// MissingExpectingKey can happen at the same time as UnexpectedKey -- so while it might seem to make				// sense to regenerate the key file automatically in this case, it could overwrite keys that someone				// wants present there when they want SSH_ALLOW_UNEXPECTED_AUTHORIZED_KEYS=true but haven't set it yet.				// So, just warn as this isn't an insecure situation.				log.Warn("authorized_keys is missing a key from the database; regenerate authorized_keys from the admin panel to repair this")			}		} 		if len(unexpectedKeys) > 0 {			detailConcat := strings.Join(unexpectedKeys, "\n\t")			log.Fatal("An unexpected ssh public key was discovered. Forgejo will shutdown to require this to be fixed. Fix by either:\n"+				"Option 1: Delete the file %s, and Forgejo will recreate it with only expected ssh public keys.\n"+				"Option 2: Permit unexpected keys by setting [server].SSH_ALLOW_UNEXPECTED_AUTHORIZED_KEYS=true in Forgejo's config file.\n\t"+				detailConcat, filepath.Join(setting.SSH.RootPath, "authorized_keys"))		}	} 	return nil}