blob: ede1ec7e9d937b0d1714b001533c87522778c50e [file] [log] [blame]
// Copyright 2021 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package report
import (
"fmt"
"io"
"net/http"
"os"
"regexp"
"strings"
"golang.org/x/mod/modfile"
"golang.org/x/mod/module"
"golang.org/x/mod/semver"
"golang.org/x/vulndb/internal/derrors"
)
// TODO: getting things from the proxy should all be cached so we
// aren't re-requesting the same stuff over and over.
var proxyURL = "https://proxy.golang.org"
func init() {
if proxy, ok := os.LookupEnv("GOPROXY"); ok {
proxyURL = proxy
}
}
func proxyLookup(urlSuffix string) ([]byte, error) {
url := fmt.Sprintf("%s/%s", proxyURL, urlSuffix)
resp, err := http.Get(url)
if err != nil {
return nil, err
} else if resp.StatusCode != 200 {
return nil, fmt.Errorf("http.Get(%q) returned status %v", url, resp.Status)
}
defer resp.Body.Close()
b, err := io.ReadAll(resp.Body)
if err != nil {
return nil, err
}
return b, nil
}
func getModVersionsFromProxy(path string) (_ map[string]bool, err error) {
escaped, err := module.EscapePath(path)
if err != nil {
return nil, err
}
b, err := proxyLookup(fmt.Sprintf("%s/@v/list", escaped))
if err != nil {
return nil, err
}
versions := map[string]bool{}
for _, v := range strings.Split(string(b), "\n") {
versions[v] = true
}
return versions, nil
}
func getCanonicalModNameFromProxy(path, version string) (_ string, err error) {
escapedPath, err := module.EscapePath(path)
if err != nil {
return "", err
}
escapedVersion, err := module.EscapeVersion(version)
if err != nil {
return "", err
}
b, err := proxyLookup(fmt.Sprintf("%s/@v/%s.mod", escapedPath, escapedVersion))
if err != nil {
return "", err
}
m, err := modfile.ParseLax("go.mod", b, nil)
if err != nil {
return "", err
}
if m.Module == nil {
return "", fmt.Errorf("unable to retrieve module information for %s", path)
}
return m.Module.Mod.Path, nil
}
var pseudoVersionRE = regexp.MustCompile(`^v[0-9]+\.(0\.0-|\d+\.\d+-([^+]*\.)?0\.)\d{14}-[A-Za-z0-9]+(\+[0-9A-Za-z-]+(\.[0-9A-Za-z-]+)*)?$`)
// isPseudoVersion reports whether v is a pseudo-version.
// NOTE: this is taken from cmd/go/internal/modfetch/pseudo.go but
// uses regexp instead of the internal lazyregex package.
func isPseudoVersion(v string) bool {
return strings.Count(v, "-") >= 2 && semver.IsValid(v) && pseudoVersionRE.MatchString(v)
}
func versionExists(version string, versions map[string]bool) (err error) {
// TODO: for now, don't check validity of pseudo-versions.
// We should add a check that the pseudo-version could feasibly exist given
// the actual versions that we know about.
//
// The pseudo-version check should probably take into account the canonical
// import path (investigate cmd/go/internal/modfetch/coderepo.go has, which
// has something like this, check the error containing "has post-%v module
// path").
if isPseudoVersion(version) {
return nil
}
if !versions[version] {
return fmt.Errorf("proxy unaware of version")
}
return nil
}
func checkModVersions(modPath string, vrs []VersionRange) (err error) {
foundVersions, err := getModVersionsFromProxy(modPath)
if err != nil {
return fmt.Errorf("unable to retrieve module versions from proxy: %s", err)
}
checkVersion := func(v Version) error {
if v == "" {
return nil
}
if err := module.Check(modPath, v.V()); err != nil {
return err
}
if err := versionExists(v.V(), foundVersions); err != nil {
return err
}
canonicalPath, err := getCanonicalModNameFromProxy(modPath, v.V())
if err != nil {
return fmt.Errorf("unable to retrieve canonical module path from proxy: %s", err)
}
if canonicalPath != modPath {
return fmt.Errorf("invalid module path %q at version %q (canonical path is %q)", modPath, v, canonicalPath)
}
return nil
}
for _, vr := range vrs {
for _, v := range []Version{vr.Introduced, vr.Fixed} {
if err := checkVersion(v); err != nil {
return fmt.Errorf("bad version %q: %s", v, err)
}
}
}
return nil
}
// LintFile is used to lint the reports/ directory. It is run by
// TestLintReports (in the vulndb repo) to ensure that there are no errors in
// the YAML reports.
func LintFile(filename string) (_ []string, err error) {
defer derrors.Wrap(&err, "LintFile(%q)", filename)
r, err := Read(filename)
if err != nil {
return nil, err
}
return r.Lint(), nil
}
func (p *Package) lintStdLibPkg(addPkgIssue func(string)) {
if p.Package == "" {
addPkgIssue("missing package")
}
}
func (p *Package) lintThirdPartyPkg(addPkgIssue func(string)) {
if p.Module == "" {
addPkgIssue("missing module")
return
}
if p.Package == p.Module {
addPkgIssue("package is redundant and can be removed")
}
if p.Package != "" && !strings.HasPrefix(p.Package, p.Module) {
addPkgIssue("module must be a prefix of package")
}
if err := checkModVersions(p.Module, p.Versions); err != nil {
addPkgIssue(err.Error())
}
importPath := p.Package
if p.Package == "" {
importPath = p.Module
}
if err := module.CheckImportPath(importPath); err != nil {
addPkgIssue(err.Error())
}
}
func (p *Package) lintVersions(addPkgIssue func(string)) {
for i, vr := range p.Versions {
for _, v := range []Version{vr.Introduced, vr.Fixed} {
if v != "" && !v.IsValid() {
addPkgIssue(fmt.Sprintf("invalid semantic version: %q", v))
}
}
if vr.Fixed != "" && !vr.Introduced.Before(vr.Fixed) {
addPkgIssue(
fmt.Sprintf("version %q >= %q", vr.Introduced, vr.Fixed))
continue
}
// Check all previous version ranges to ensure none overlap with
// this one.
for _, vrPrev := range p.Versions[:i] {
if vrPrev.Introduced.Before(vr.Fixed) && vr.Introduced.Before(vrPrev.Fixed) {
addPkgIssue(fmt.Sprintf("version ranges overlap: [%v,%v), [%v,%v)", vr.Introduced, vr.Fixed, vr.Introduced, vrPrev.Fixed))
}
}
}
}
var cveRegex = regexp.MustCompile(`^CVE-\d{4}-\d{4,}$`)
func (r *Report) lintCVEs(addIssue func(string)) {
if len(r.CVEs) > 0 && r.CVEMetadata != nil && r.CVEMetadata.ID != "" {
// TODO: consider removing one of these fields from the Report struct.
addIssue("only one of cve and cve_metadata.id should be present")
}
for _, cve := range r.CVEs {
if !cveRegex.MatchString(cve) {
addIssue("malformed cve identifier")
}
}
if r.CVEMetadata != nil {
if r.CVEMetadata.ID == "" {
addIssue("cve_metadata.id is required")
} else if !cveRegex.MatchString(r.CVEMetadata.ID) {
addIssue("malformed cve_metadata.id identifier")
}
}
}
func (r *Report) lintLinks(addIssue func(string)) {
links := append(r.Links.Context, r.Links.Commit, r.Links.PR)
for _, l := range links {
if !isValidURL(l) {
addIssue(fmt.Sprintf("%q should be %q", l, fixURL(l)))
}
}
}
// Lint checks the content of a Report and outputs a list of strings
// representing lint errors.
// TODO: It might make sense to include warnings or informational things
// alongside errors, especially during for use during the triage process.
func (r *Report) Lint() []string {
var issues []string
addIssue := func(iss string) {
issues = append(issues, iss)
}
if len(r.Packages) == 0 {
addIssue("no packages")
}
for i, p := range r.Packages {
addPkgIssue := func(iss string) {
addIssue(fmt.Sprintf("packages[%v]: %v", i, iss))
}
if p.Module == "std" {
p.lintStdLibPkg(addPkgIssue)
} else {
p.lintThirdPartyPkg(addPkgIssue)
}
p.lintVersions(addPkgIssue)
}
if r.Description == "" {
addIssue("missing description")
}
if r.LastModified != nil && r.LastModified.Before(r.Published) {
addIssue("last_modified is before published")
}
r.lintCVEs(addIssue)
r.lintLinks(addIssue)
return issues
}
func (r *Report) Fix() {
r.Links.Commit = fixURL(r.Links.Commit)
r.Links.PR = fixURL(r.Links.PR)
var fixed []string
for _, l := range r.Links.Context {
fixed = append(fixed, fixURL(l))
}
fixVersion := func(vp *Version) {
v := *vp
if v == "" {
return
}
v = Version(strings.TrimPrefix(string(v), "v"))
v = Version(strings.TrimPrefix(string(v), "go"))
if v.IsValid() {
build := semver.Build(v.V())
v = Version(v.Canonical())
if build != "" {
v += Version("+" + build)
}
}
*vp = v
}
for i, p := range r.Packages {
for j, _ := range p.Versions {
fixVersion(&r.Packages[i].Versions[j].Introduced)
fixVersion(&r.Packages[i].Versions[j].Fixed)
}
}
r.Links.Context = fixed
}
var urlReplacements = []struct {
re *regexp.Regexp
repl string
}{{
regexp.MustCompile(`golang.org`),
`go.dev`,
}, {
regexp.MustCompile(`https?://groups.google.com/forum/\#\![^/]*/([^/]+)/([^/]+)/(.*)`),
`https://groups.google.com/g/$1/c/$2/m/$3`,
}, {
regexp.MustCompile(`.*github.com/golang/go/issues`),
`https://go.dev/issue`,
}, {
regexp.MustCompile(`.*github.com/golang/go/commit`),
`https://go.googlesource.com/+`,
}}
func isValidURL(u string) bool {
return fixURL(u) == u
}
func fixURL(u string) string {
for _, repl := range urlReplacements {
u = repl.re.ReplaceAllString(u, repl.repl)
}
return u
}