forgejo/services/repository/files/patch.go
wxiaoguang 6bc3079c00
Refactor git command package to improve security and maintainability (#22678)
This PR follows #21535 (and replace #22592)

## Review without space diff

https://github.com/go-gitea/gitea/pull/22678/files?diff=split&w=1

## Purpose of this PR

1. Make git module command completely safe (risky user inputs won't be
passed as argument option anymore)
2. Avoid low-level mistakes like
https://github.com/go-gitea/gitea/pull/22098#discussion_r1045234918
3. Remove deprecated and dirty `CmdArgCheck` function, hide the `CmdArg`
type
4. Simplify code when using git command

## The main idea of this PR

* Move the `git.CmdArg` to the `internal` package, then no other package
except `git` could use it. Then developers could never do
`AddArguments(git.CmdArg(userInput))` any more.
* Introduce `git.ToTrustedCmdArgs`, it's for user-provided and already
trusted arguments. It's only used in a few cases, for example: use git
arguments from config file, help unit test with some arguments.
* Introduce `AddOptionValues` and `AddOptionFormat`, they make code more
clear and simple:
    * Before: `AddArguments("-m").AddDynamicArguments(message)`
    * After: `AddOptionValues("-m", message)`
    * -
* Before: `AddArguments(git.CmdArg(fmt.Sprintf("--author='%s <%s>'",
sig.Name, sig.Email)))`
* After: `AddOptionFormat("--author='%s <%s>'", sig.Name, sig.Email)`

## FAQ

### Why these changes were not done in #21535 ?

#21535 is mainly a search&replace, it did its best to not change too
much logic.

Making the framework better needs a lot of changes, so this separate PR
is needed as the second step.


### The naming of `AddOptionXxx`

According to git's manual, the `--xxx` part is called `option`.

### How can it guarantee that `internal.CmdArg` won't be not misused?

Go's specification guarantees that. Trying to access other package's
internal package causes compilation error.

And, `golangci-lint` also denies the git/internal package. Only the
`git/command.go` can use it carefully.

### There is still a `ToTrustedCmdArgs`, will it still allow developers
to make mistakes and pass untrusted arguments?

Generally speaking, no. Because when using `ToTrustedCmdArgs`, the code
will be very complex (see the changes for examples). Then developers and
reviewers can know that something might be unreasonable.

### Why there was a `CmdArgCheck` and why it's removed?

At the moment of #21535, to reduce unnecessary changes, `CmdArgCheck`
was introduced as a hacky patch. Now, almost all code could be written
as `cmd := NewCommand(); cmd.AddXxx(...)`, then there is no need for
`CmdArgCheck` anymore.


### Why many codes for `signArg == ""` is deleted?

Because in the old code, `signArg` could never be empty string, it's
either `-S[key-id]` or `--no-gpg-sign`. So the `signArg == ""` is just
dead code.

---------

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
2023-02-04 10:30:43 +08:00

193 lines
5.4 KiB
Go

// Copyright 2021 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package files
import (
"context"
"fmt"
"strings"
"code.gitea.io/gitea/models"
git_model "code.gitea.io/gitea/models/git"
repo_model "code.gitea.io/gitea/models/repo"
user_model "code.gitea.io/gitea/models/user"
"code.gitea.io/gitea/modules/git"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/structs"
asymkey_service "code.gitea.io/gitea/services/asymkey"
)
// ApplyDiffPatchOptions holds the repository diff patch update options
type ApplyDiffPatchOptions struct {
LastCommitID string
OldBranch string
NewBranch string
Message string
Content string
SHA string
Author *IdentityOptions
Committer *IdentityOptions
Dates *CommitDateOptions
Signoff bool
}
// Validate validates the provided options
func (opts *ApplyDiffPatchOptions) Validate(ctx context.Context, repo *repo_model.Repository, doer *user_model.User) error {
// If no branch name is set, assume master
if opts.OldBranch == "" {
opts.OldBranch = repo.DefaultBranch
}
if opts.NewBranch == "" {
opts.NewBranch = opts.OldBranch
}
gitRepo, closer, err := git.RepositoryFromContextOrOpen(ctx, repo.RepoPath())
if err != nil {
return err
}
defer closer.Close()
// oldBranch must exist for this operation
if _, err := gitRepo.GetBranch(opts.OldBranch); err != nil {
return err
}
// A NewBranch can be specified for the patch to be applied to.
// Check to make sure the branch does not already exist, otherwise we can't proceed.
// If we aren't branching to a new branch, make sure user can commit to the given branch
if opts.NewBranch != opts.OldBranch {
existingBranch, err := gitRepo.GetBranch(opts.NewBranch)
if existingBranch != nil {
return models.ErrBranchAlreadyExists{
BranchName: opts.NewBranch,
}
}
if err != nil && !git.IsErrBranchNotExist(err) {
return err
}
} else {
protectedBranch, err := git_model.GetFirstMatchProtectedBranchRule(ctx, repo.ID, opts.OldBranch)
if err != nil {
return err
}
if protectedBranch != nil {
protectedBranch.Repo = repo
if !protectedBranch.CanUserPush(ctx, doer) {
return models.ErrUserCannotCommit{
UserName: doer.LowerName,
}
}
}
if protectedBranch != nil && protectedBranch.RequireSignedCommits {
_, _, _, err := asymkey_service.SignCRUDAction(ctx, repo.RepoPath(), doer, repo.RepoPath(), opts.OldBranch)
if err != nil {
if !asymkey_service.IsErrWontSign(err) {
return err
}
return models.ErrUserCannotCommit{
UserName: doer.LowerName,
}
}
}
}
return nil
}
// ApplyDiffPatch applies a patch to the given repository
func ApplyDiffPatch(ctx context.Context, repo *repo_model.Repository, doer *user_model.User, opts *ApplyDiffPatchOptions) (*structs.FileResponse, error) {
if err := opts.Validate(ctx, repo, doer); err != nil {
return nil, err
}
message := strings.TrimSpace(opts.Message)
author, committer := GetAuthorAndCommitterUsers(opts.Author, opts.Committer, doer)
t, err := NewTemporaryUploadRepository(ctx, repo)
if err != nil {
log.Error("%v", err)
}
defer t.Close()
if err := t.Clone(opts.OldBranch); err != nil {
return nil, err
}
if err := t.SetDefaultIndex(); err != nil {
return nil, err
}
// Get the commit of the original branch
commit, err := t.GetBranchCommit(opts.OldBranch)
if err != nil {
return nil, err // Couldn't get a commit for the branch
}
// Assigned LastCommitID in opts if it hasn't been set
if opts.LastCommitID == "" {
opts.LastCommitID = commit.ID.String()
} else {
lastCommitID, err := t.gitRepo.ConvertToSHA1(opts.LastCommitID)
if err != nil {
return nil, fmt.Errorf("ApplyPatch: Invalid last commit ID: %w", err)
}
opts.LastCommitID = lastCommitID.String()
if commit.ID.String() != opts.LastCommitID {
return nil, models.ErrCommitIDDoesNotMatch{
GivenCommitID: opts.LastCommitID,
CurrentCommitID: opts.LastCommitID,
}
}
}
stdout := &strings.Builder{}
stderr := &strings.Builder{}
cmdApply := git.NewCommand(ctx, "apply", "--index", "--recount", "--cached", "--ignore-whitespace", "--whitespace=fix", "--binary")
if git.CheckGitVersionAtLeast("2.32") == nil {
cmdApply.AddArguments("-3")
}
if err := cmdApply.Run(&git.RunOpts{
Dir: t.basePath,
Stdout: stdout,
Stderr: stderr,
Stdin: strings.NewReader(opts.Content),
}); err != nil {
return nil, fmt.Errorf("Error: Stdout: %s\nStderr: %s\nErr: %w", stdout.String(), stderr.String(), err)
}
// Now write the tree
treeHash, err := t.WriteTree()
if err != nil {
return nil, err
}
// Now commit the tree
var commitHash string
if opts.Dates != nil {
commitHash, err = t.CommitTreeWithDate("HEAD", author, committer, treeHash, message, opts.Signoff, opts.Dates.Author, opts.Dates.Committer)
} else {
commitHash, err = t.CommitTree("HEAD", author, committer, treeHash, message, opts.Signoff)
}
if err != nil {
return nil, err
}
// Then push this tree to NewBranch
if err := t.Push(doer, commitHash, opts.NewBranch); err != nil {
return nil, err
}
commit, err = t.GetCommit(commitHash)
if err != nil {
return nil, err
}
fileCommitResponse, _ := GetFileCommitResponse(repo, commit) // ok if fails, then will be nil
verification := GetPayloadCommitVerification(commit)
fileResponse := &structs.FileResponse{
Commit: fileCommitResponse,
Verification: verification,
}
return fileResponse, nil
}