scorecard/checks/branch_protected.go
evalphobia a4f7d4b5b4
🐛 Fix panic error when RequiredPullRequestReviews is nil (#768)
* Fix panic error when RequiredPullRequestReviews is nil

* add test
2021-07-28 09:57:26 -04:00

268 lines
9.1 KiB
Go

// Copyright 2020 Security Scorecard Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package checks
import (
"context"
"fmt"
"regexp"
"github.com/google/go-github/v32/github"
"github.com/ossf/scorecard/v2/checker"
sce "github.com/ossf/scorecard/v2/errors"
)
const (
CheckBranchProtection = "Branch-Protection"
minReviews = 2
)
//nolint:gochecknoinits
func init() {
registerCheck(CheckBranchProtection, BranchProtection)
}
type repositories interface {
Get(context.Context, string, string) (*github.Repository,
*github.Response, error)
ListBranches(ctx context.Context, owner string, repo string,
opts *github.BranchListOptions) ([]*github.Branch, *github.Response, error)
ListReleases(ctx context.Context, owner string, repo string, opts *github.ListOptions) (
[]*github.RepositoryRelease, *github.Response, error)
GetBranchProtection(context.Context, string, string, string) (
*github.Protection, *github.Response, error)
}
func BranchProtection(c *checker.CheckRequest) checker.CheckResult {
// Checks branch protection on both release and development branch.
return checkReleaseAndDevBranchProtection(c.Ctx, c.Client.Repositories, c.Dlogger, c.Owner, c.Repo)
}
func checkReleaseAndDevBranchProtection(ctx context.Context, r repositories, dl checker.DetailLogger, ownerStr,
repoStr string) checker.CheckResult {
// Get all branches. This will include information on whether they are protected.
branches, _, err := r.ListBranches(ctx, ownerStr, repoStr, &github.BranchListOptions{})
if err != nil {
return checker.CreateRuntimeErrorResult(CheckBranchProtection, err)
}
// Get release branches
releases, _, err := r.ListReleases(ctx, ownerStr, repoStr, &github.ListOptions{})
if err != nil {
return checker.CreateRuntimeErrorResult(CheckBranchProtection, err)
}
var checks []checker.CheckResult
commit := regexp.MustCompile("^[a-f0-9]{40}$")
checkBranches := make(map[string]bool)
for _, release := range releases {
if release.TargetCommitish == nil {
// Log with a named error if target_commitish is nil.
e := sce.Create(sce.ErrScorecardInternal, errInternalCommitishNil.Error())
r := checker.CreateRuntimeErrorResult(CheckBranchProtection, e)
checks = append(checks, r)
continue
}
// TODO: if this is a sha, get the associated branch. for now, ignore.
if commit.Match([]byte(*release.TargetCommitish)) {
continue
}
// Try to resolve the branch name.
name, err := resolveBranchName(branches, *release.TargetCommitish)
if err != nil {
// If the commitish branch is still not found, fail.
r := checker.CreateRuntimeErrorResult(CheckBranchProtection, err)
checks = append(checks, r)
continue
}
// Branch is valid, add to list of branches to check.
checkBranches[*name] = true
}
// Add default branch.
repo, _, err := r.Get(ctx, ownerStr, repoStr)
if err != nil {
return checker.CreateRuntimeErrorResult(CheckBranchProtection, err)
}
checkBranches[*repo.DefaultBranch] = true
// Check protections on the branches.
for b := range checkBranches {
protected, err := isBranchProtected(branches, b)
if err != nil {
r := checker.CreateRuntimeErrorResult(CheckBranchProtection, err)
checks = append(checks, r)
}
if !protected {
r := checker.CreateMinScoreResult(CheckBranchProtection,
fmt.Sprintf("branch protection not enabled for branch '%s'", b))
checks = append(checks, r)
} else {
// The branch is protected. Check the protection.
res := getProtectionAndCheck(ctx, r, dl, ownerStr, repoStr, b)
checks = append(checks, res)
}
}
return checker.MakeAndResult2(checks...)
}
func resolveBranchName(branches []*github.Branch, name string) (*string, error) {
// First check list of branches.
for _, b := range branches {
if b.GetName() == name {
return b.Name, nil
}
}
// Ideally, we should check using repositories.GetBranch if there was a branch redirect.
// See https://github.com/google/go-github/issues/1895
// For now, handle the common master -> main redirect.
if name == "master" {
return resolveBranchName(branches, "main")
}
//nolint
return nil, sce.Create(sce.ErrScorecardInternal, errInternalBranchNotFound.Error())
}
func isBranchProtected(branches []*github.Branch, name string) (bool, error) {
// Returns bool indicating if protected.
for _, b := range branches {
if b.GetName() == name {
return b.GetProtected(), nil
}
}
//nolint
return false, sce.Create(sce.ErrScorecardInternal, errInternalBranchNotFound.Error())
}
func getProtectionAndCheck(ctx context.Context, r repositories, dl checker.DetailLogger, ownerStr, repoStr,
branch string) checker.CheckResult {
// We only call this if the branch is protected. An error indicates not found.
protection, _, err := r.GetBranchProtection(ctx, ownerStr, repoStr, branch)
if err != nil {
e := sce.Create(sce.ErrScorecardInternal, err.Error())
return checker.CreateRuntimeErrorResult(CheckBranchProtection, e)
}
return IsBranchProtected(protection, branch, dl)
}
func IsBranchProtected(protection *github.Protection, branch string, dl checker.DetailLogger) checker.CheckResult {
totalChecks := 10
totalSuccess := 0
// This is disabled by default (good).
if protection.GetAllowForcePushes() != nil &&
protection.AllowForcePushes.Enabled {
dl.Warn("AllowForcePushes enabled on branch '%s'", branch)
} else {
dl.Info("AllowForcePushes disabled on branch '%s'", branch)
totalSuccess++
}
// This is disabled by default (good).
if protection.GetAllowDeletions() != nil &&
protection.AllowDeletions.Enabled {
dl.Warn("AllowDeletions enabled on branch '%s'", branch)
} else {
dl.Info("AllowDeletions disabled on branch '%s'", branch)
totalSuccess++
}
// This is disabled by default (bad).
if protection.GetEnforceAdmins() != nil &&
protection.EnforceAdmins.Enabled {
dl.Info("EnforceAdmins disabled on branch '%s'", branch)
totalSuccess++
} else {
dl.Warn("EnforceAdmins disabled on branch '%s'", branch)
}
// This is disabled by default (bad).
if protection.GetRequireLinearHistory() != nil &&
protection.RequireLinearHistory.Enabled {
dl.Info("Linear history enabled on branch '%s'", branch)
totalSuccess++
} else {
dl.Warn("Linear history disabled on branch '%s'", branch)
}
if requiresStatusChecks(protection, branch, dl) {
dl.Info("Strict status check enabled on branch '%s'", branch)
totalSuccess++
}
if requiresThoroughReviews(protection, branch, dl) {
totalSuccess++
}
return checker.CreateProportionalScoreResult(CheckBranchProtection,
"%d out of %d branch protection settings are enabled", totalSuccess, totalChecks)
}
// Returns true if several PR status checks requirements are enabled. Otherwise returns false and logs why it failed.
func requiresStatusChecks(protection *github.Protection, branch string, dl checker.DetailLogger) bool {
// This is disabled by default (bad).
if protection.GetRequiredStatusChecks() != nil &&
protection.RequiredStatusChecks.Strict &&
len(protection.RequiredStatusChecks.Contexts) > 0 {
return true
}
switch {
case protection.RequiredStatusChecks == nil ||
!protection.RequiredStatusChecks.Strict:
dl.Warn("Status checks for merging disabled on branch '%s'", branch)
case len(protection.RequiredStatusChecks.Contexts) == 0:
dl.Warn("Status checks for merging have no specific status to check on branch '%s'", branch)
default:
panic("Unhandled status checks error")
}
return false
}
// Returns true if several PR review requirements are enabled. Otherwise returns false and logs why it failed.
func requiresThoroughReviews(protection *github.Protection, branch string, dl checker.DetailLogger) bool {
// This is disabled by default (bad).
if protection.GetRequiredPullRequestReviews() != nil &&
protection.RequiredPullRequestReviews.RequiredApprovingReviewCount >= minReviews &&
protection.RequiredPullRequestReviews.DismissStaleReviews &&
protection.RequiredPullRequestReviews.RequireCodeOwnerReviews {
return true
}
if protection.RequiredPullRequestReviews == nil {
dl.Warn("Pullrequest reviews disabled on branch '%s'", branch)
return false
}
switch {
case protection.RequiredPullRequestReviews.RequiredApprovingReviewCount < minReviews:
dl.Warn("Number of required reviewers is only %d on branch '%s'",
protection.RequiredPullRequestReviews.RequiredApprovingReviewCount, branch)
fallthrough
case !protection.RequiredPullRequestReviews.DismissStaleReviews:
dl.Warn("Stale review dismissal disabled on branch '%s'", branch)
fallthrough
case !protection.RequiredPullRequestReviews.RequireCodeOwnerReviews:
dl.Warn("Owner review not required on branch '%s'", branch)
default:
panic("Unhandled pull request error")
}
return false
}