cli/pkg/cmd/attestation/verify/policy.go
Meredith Lancaster 149a78a23c formatter
Signed-off-by: Meredith Lancaster <malancas@github.com>
2024-03-04 15:42:08 -07:00

85 lines
2.4 KiB
Go

package verify
import (
"fmt"
"github.com/sigstore/sigstore-go/pkg/fulcio/certificate"
"github.com/sigstore/sigstore-go/pkg/verify"
"github.com/cli/cli/v2/pkg/cmd/attestation/artifact"
"github.com/cli/cli/v2/pkg/cmd/attestation/verification"
)
const (
GitHubOIDCIssuer = "https://token.actions.githubusercontent.com"
SLSAPredicateType = "https://slsa.dev/provenance/v1"
// represents the GitHub hosted runner in the certificate RunnerEnvironment extension
GitHubRunner = "github-hosted"
)
func buildSANMatcher(san, sanRegex string) (verify.SubjectAlternativeNameMatcher, error) {
if san == "" && sanRegex == "" {
return verify.SubjectAlternativeNameMatcher{}, nil
}
sanMatcher, err := verify.NewSANMatcher(san, "", sanRegex)
if err != nil {
return verify.SubjectAlternativeNameMatcher{}, err
}
return sanMatcher, nil
}
func buildCertificateIdentityOption(opts *Options, runnerEnv string) (verify.PolicyOption, error) {
sanMatcher, err := buildSANMatcher(opts.SAN, opts.SANRegex)
if err != nil {
return nil, err
}
extensions := certificate.Extensions{
Issuer: opts.OIDCIssuer,
SourceRepositoryOwnerURI: fmt.Sprintf("https://github.com/%s", opts.Owner),
RunnerEnvironment: runnerEnv,
}
certId, err := verify.NewCertificateIdentity(sanMatcher, extensions)
if err != nil {
return nil, err
}
return verify.WithCertificateIdentity(certId), nil
}
func buildVerifyCertIdOption(opts *Options) (verify.PolicyOption, error) {
if opts.DenySelfHostedRunner {
withGHRunner, err := buildCertificateIdentityOption(opts, GitHubRunner)
if err != nil {
return nil, err
}
return withGHRunner, nil
}
// if Extensions.RunnerEnvironment value is set to the empty string
// through the second function argument,
// no certificate matching will happen on the RunnerEnvironment field
withAnyRunner, err := buildCertificateIdentityOption(opts, "")
if err != nil {
return nil, err
}
return withAnyRunner, nil
}
func buildVerifyPolicy(opts *Options, a artifact.DigestedArtifact) (verify.PolicyBuilder, error) {
artifactDigestPolicyOption, err := verification.BuildDigestPolicyOption(a)
if err != nil {
return verify.PolicyBuilder{}, err
}
certIdOption, err := buildVerifyCertIdOption(opts)
if err != nil {
return verify.PolicyBuilder{}, err
}
policy := verify.NewPolicy(artifactDigestPolicyOption, certIdOption)
return policy, nil
}