Files
attest/pkg/tuf/version.go
Jonny Stoten 6397dcede8 Check version of attest against constraints in TUF (#19)
* Check version of attest against constraints in TUF

* Add link to semver lib constraints docs
2024-05-22 17:02:25 +01:00

90 lines
2.3 KiB
Go

package tuf
import (
"fmt"
"runtime/debug"
"strings"
"github.com/Masterminds/semver/v3"
)
const ThisModulePath = "github.com/docker/attest"
type VersionChecker interface {
// CheckVersion checks if the current version of this library meets the constraints from the TUF repo
CheckVersion(tufClient TUFClient) error
}
type InvalidVersionError struct {
AttestVersion string
VersionConstraint string
Errors []error
}
func (e *InvalidVersionError) Error() string {
var errsStr strings.Builder
for i, err := range e.Errors {
if i > 0 {
errsStr.WriteString("; ")
}
errsStr.WriteString(err.Error())
}
return fmt.Sprintf("%s version %s does not satisfy constraints %s: %s", ThisModulePath, e.AttestVersion, e.VersionConstraint, errsStr.String())
}
func NewVersionChecker() *versionChecker {
return &versionChecker{}
}
type versionChecker struct{}
func (vc *versionChecker) CheckVersion(client TUFClient) error {
var attestMod *debug.Module
bi, ok := debug.ReadBuildInfo()
if !ok {
// if we can't read the build info, assume we're good. this should only happen if we're not running in a module
return nil
}
if bi.Main.Path == ThisModulePath {
attestMod = &bi.Main
} else {
for _, dep := range bi.Deps {
if dep.Path == ThisModulePath {
attestMod = dep
break
}
}
}
if attestMod == nil {
// if we can't find the attest dep, assume we're good. this should only happen in a test
return nil
}
attestVersion, err := semver.NewVersion(attestMod.Version)
if err != nil {
return fmt.Errorf("failed to parse version %s: %w", attestMod.Version, err)
}
// see https://github.com/Masterminds/semver/blob/v3.2.1/README.md#checking-version-constraints
// for more information on the expected format of the version constraints in the TUF repo
_, versionConstraintsBytes, err := client.DownloadTarget("version-constraints", "")
if err != nil {
return fmt.Errorf("failed to download version-constraints: %w", err)
}
versionConstraints, err := semver.NewConstraint(string(versionConstraintsBytes))
if err != nil {
return fmt.Errorf("failed to parse minimum version: %w", err)
}
ok, errs := versionConstraints.Validate(attestVersion)
if !ok {
return &InvalidVersionError{
AttestVersion: attestVersion.String(),
VersionConstraint: versionConstraints.String(),
Errors: errs,
}
}
return nil
}