Files
buildx/policy/default_test.go
T
Tonis Tiigi 0491d7c7b9 policy: add default policy for buildkit-syft-scanner images
Extends the builtin default policy to verify docker-github-builder
signatures on docker/buildkit-syft-scanner images. Tags `latest` and
1.10+ require a signature from the docker/buildkit-syft-scanner source
repository; older tags pass through unchanged. Factors the shared ref
matching logic into sig_ref_matches for dockerfile and introduces a
syft-scanner variant that uses the plain refs/tags/ prefix.

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
2026-04-20 16:46:05 -07:00

403 lines
14 KiB
Go

package policy
import (
"context"
"testing"
"time"
gwpb "github.com/moby/buildkit/frontend/gateway/pb"
"github.com/moby/buildkit/solver/pb"
moby_buildkit_v1_sourcepolicy "github.com/moby/buildkit/sourcepolicy/pb"
"github.com/moby/buildkit/sourcepolicy/policysession"
policyimage "github.com/moby/policy-helpers/image"
policytypes "github.com/moby/policy-helpers/types"
ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
"github.com/sigstore/sigstore-go/pkg/fulcio/certificate"
"github.com/sirupsen/logrus"
"github.com/stretchr/testify/require"
)
// makeDefaultPolicy returns a Policy instance backed by the embedded
// default policy module, optionally wired to a mock signature verifier
// returning the supplied SignatureInfo for image attestations.
func makeDefaultPolicy(t *testing.T, sigInfo *policytypes.SignatureInfo) *Policy {
t.Helper()
var verifierProvider PolicyVerifierProvider
if sigInfo != nil {
verifierProvider = func() (PolicyVerifier, error) {
return &mockPolicyVerifier{
verifyImage: func(_ context.Context, _ policyimage.ReferrersProvider, _ ocispecs.Descriptor, _ *ocispecs.Platform) (*policytypes.SignatureInfo, error) {
return sigInfo, nil
},
}, nil
}
}
return NewPolicy(Opt{
Files: []File{{
Filename: DefaultPolicyFilename,
Data: DefaultPolicyData(),
}},
Log: func(level logrus.Level, msg string) {
t.Logf("[%s] %s", level, msg)
},
VerifierProvider: verifierProvider,
})
}
// dockerGithubBuilderSig returns a SignatureInfo that satisfies the
// docker_github_builder_signature helper for the given source repository
// and ref. Pass an empty ref to omit the SourceRepositoryRef field.
func dockerGithubBuilderSig(sourceRepo, sourceRef string) *policytypes.SignatureInfo {
return &policytypes.SignatureInfo{
Kind: policytypes.KindDockerGithubBuilder,
SignatureType: policytypes.SignatureBundleV03,
Timestamps: []policytypes.TimestampVerificationResult{
{Type: "rekor", URI: "https://rekor.sigstore.dev", Timestamp: time.Date(2024, 1, 1, 0, 0, 0, 0, time.UTC)},
},
Signer: &certificate.Summary{
CertificateIssuer: "CN=sigstore-intermediate,O=sigstore.dev",
Extensions: certificate.Extensions{
Issuer: "https://token.actions.githubusercontent.com",
SourceRepositoryURI: "https://github.com/" + sourceRepo,
SourceRepositoryRef: sourceRef,
RunnerEnvironment: "github-hosted",
},
},
}
}
// runDefaultPolicyImage evaluates the default policy against the given image
// reference. An attestation chain and an empty image config are always
// supplied so that the policy can fully resolve metadata and produce a
// decision (rather than requesting more data via the next response).
func runDefaultPolicyImage(t *testing.T, p *Policy, ref string) *policysession.DecisionResponse {
t.Helper()
src := &gwpb.ResolveSourceMetaResponse{
Source: &pb.SourceOp{Identifier: "docker-image://" + ref},
Image: &gwpb.ResolveSourceImageResponse{
Digest: "sha256:abababababababababababababababababababababababababababababababab",
Config: []byte(`{"created":"2024-01-01T00:00:00Z","config":{}}`),
AttestationChain: newTestAttestationChain(t),
},
}
resp, _, err := p.CheckPolicy(context.Background(), &policysession.CheckPolicyRequest{
Platform: &pb.Platform{OS: "linux", Architecture: "amd64"},
Source: src,
})
require.NoError(t, err)
require.NotNil(t, resp)
return resp
}
func TestDefaultPolicyAllowsNonImageSources(t *testing.T) {
p := makeDefaultPolicy(t, nil)
src := &gwpb.ResolveSourceMetaResponse{
Source: &pb.SourceOp{Identifier: "https://example.com/foo.tar.gz"},
HTTP: &gwpb.ResolveSourceHTTPResponse{
Checksum: "sha256:0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef",
},
}
resp, _, err := p.CheckPolicy(context.Background(), &policysession.CheckPolicyRequest{
Source: src,
})
require.NoError(t, err)
require.Equal(t, moby_buildkit_v1_sourcepolicy.PolicyAction_ALLOW, resp.Action)
}
func TestDefaultPolicyImages(t *testing.T) {
testCases := []struct {
name string
sig *policytypes.SignatureInfo
ref string
allow bool
denyMsg string
}{
{
name: "allows_unrelated_images",
ref: "alpine:latest",
allow: true,
},
{
name: "dockerfile_digest_only_always_allowed",
ref: "docker/dockerfile@sha256:cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc",
allow: true,
},
{
name: "dockerfile_tagged_digest_denied",
ref: "docker/dockerfile:1.21.0@sha256:cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc",
denyMsg: "signature is required for 1.21.0 tag",
},
{
name: "dockerfile_old_version_allowed_unsigned",
ref: "docker/dockerfile:1.20.0",
allow: true,
},
{
name: "dockerfile_new_version_requires_signature",
ref: "docker/dockerfile:1.21.0",
denyMsg: "signature is required for 1.21.0 tag",
},
{
name: "dockerfile_new_minor_version_requires_signature",
ref: "docker/dockerfile:1.21",
denyMsg: "signature is required for 1.21 tag",
},
{
name: "dockerfile_new_major_version_requires_signature",
ref: "docker/dockerfile:1",
denyMsg: "signature is required for 1 tag",
},
{
name: "dockerfile_new_version_allowed_with_matching_signature",
sig: dockerGithubBuilderSig("moby/buildkit", "refs/tags/dockerfile/1.21.0"),
ref: "docker/dockerfile:1.21.0",
allow: true,
},
{
name: "dockerfile_new_minor_version_allowed_with_matching_patch_signature",
sig: dockerGithubBuilderSig("moby/buildkit", "refs/tags/dockerfile/1.21.0"),
ref: "docker/dockerfile:1.21",
allow: true,
},
{
name: "dockerfile_new_version_allowed_with_matching_signature_labs",
sig: dockerGithubBuilderSig("moby/buildkit", "refs/tags/dockerfile/1.21.0-labs"),
ref: "docker/dockerfile:1.21.0-labs",
allow: true,
},
{
name: "dockerfile_new_version_allowed_with_matching_signature_labs2",
sig: dockerGithubBuilderSig("moby/buildkit", "refs/tags/dockerfile/1.21.0-labs"),
ref: "docker/dockerfile:1.21-labs",
allow: true,
},
{
name: "dockerfile_new_version_allowed_with_matching_signature_labs3",
sig: dockerGithubBuilderSig("moby/buildkit", "refs/tags/dockerfile/1.21.0-labs"),
ref: "docker/dockerfile:1-labs",
allow: true,
},
{
name: "dockerfile_new_version_allowed_with_matching_signature_labs4",
sig: dockerGithubBuilderSig("moby/buildkit", "refs/tags/dockerfile/1.21.0-labs"),
ref: "docker/dockerfile:labs",
allow: true,
},
{
name: "dockerfile_new_version_denied_with_nonlabs_signature_for_labs_tag",
sig: dockerGithubBuilderSig("moby/buildkit", "refs/tags/dockerfile/1.21.0"),
ref: "docker/dockerfile:1-labs",
denyMsg: "signature is required for 1-labs tag",
},
{
name: "dockerfile_new_version_denied_with_mismatched_ref_labs",
sig: dockerGithubBuilderSig("moby/buildkit", "refs/tags/dockerfile/1.22.0-labs"),
ref: "docker/dockerfile:1.21.0-labs",
denyMsg: "signature is required for 1.21.0-labs tag",
},
{
name: "dockerfile_new_version_denied_with_nonlabs_signature_for_exact_labs_tag",
sig: dockerGithubBuilderSig("moby/buildkit", "refs/tags/dockerfile/1.21.0"),
ref: "docker/dockerfile:1.21.0-labs",
denyMsg: "signature is required for 1.21.0-labs tag",
},
{
name: "dockerfile_new_version_denied_with_wrong_signature_repo",
sig: dockerGithubBuilderSig("docker/dockerfile", "refs/tags/dockerfile/1.21.0"),
ref: "docker/dockerfile:1.21.0",
denyMsg: "signature is required for 1.21.0 tag",
},
{
name: "dockerfile_upstream_new_version_denied_with_wrong_signature_repo",
sig: dockerGithubBuilderSig("docker/dockerfile-upstream", "refs/tags/dockerfile/1.21.0"),
ref: "docker/dockerfile-upstream:1.21.0",
denyMsg: "signature is required for 1.21.0 tag",
},
{
name: "dockerfile_upstream_new_version_requires_signature",
ref: "docker/dockerfile-upstream:1.21.0",
denyMsg: "signature is required for 1.21.0 tag",
},
{
name: "dockerfile_upstream_new_version_allowed_with_matching_signature",
sig: dockerGithubBuilderSig("moby/buildkit", "refs/tags/dockerfile/1.21.0"),
ref: "docker/dockerfile-upstream:1.21.0",
allow: true,
},
{
name: "dockerfile_upstream_new_version_denied_with_mismatched_ref",
sig: dockerGithubBuilderSig("moby/buildkit", "refs/tags/dockerfile/1.22.0"),
ref: "docker/dockerfile-upstream:1.21.0",
denyMsg: "signature is required for 1.21.0 tag",
},
{
name: "dockerfile_new_version_denied_with_mismatched_ref",
sig: dockerGithubBuilderSig("moby/buildkit", "refs/tags/dockerfile/1.22.0"),
ref: "docker/dockerfile:1.21.0",
denyMsg: "signature is required for 1.21.0 tag",
},
{
name: "dockerfile_new_minor_version_denied_with_newer_patch_ref",
sig: dockerGithubBuilderSig("moby/buildkit", "refs/tags/dockerfile/1.23.0"),
ref: "docker/dockerfile:1.22",
denyMsg: "signature is required for 1.22 tag",
},
{
name: "dockerfile_new_version_denied_with_mismatched_ref_labs",
sig: dockerGithubBuilderSig("moby/buildkit", "refs/tags/dockerfile/1.22.0-labs"),
ref: "docker/dockerfile:1.21.0-labs",
denyMsg: "signature is required for 1.21.0-labs tag",
},
{
name: "dockerfile_new_version_denied_with_wrong_signature_tag",
sig: dockerGithubBuilderSig("moby/buildkit", "refs/tags/1.21.0"),
ref: "docker/dockerfile:1.21.0",
denyMsg: "signature is required for 1.21.0 tag",
},
{
name: "dockerfile_latest_allowed_with_signature_any_ref",
sig: dockerGithubBuilderSig("moby/buildkit", "refs/tags/dockerfile/1.30.0"),
ref: "docker/dockerfile:latest",
allow: true,
},
{
name: "dockerfile_latest_denied_without_signature",
ref: "docker/dockerfile:latest",
denyMsg: "signature is required for latest tag",
},
{
name: "dockerfile_upstream_latest_allowed_with_signature_any_ref",
sig: dockerGithubBuilderSig("moby/buildkit", "refs/tags/dockerfile/1.30.0"),
ref: "docker/dockerfile-upstream:latest",
allow: true,
},
{
name: "dockerfile_upstream_latest_denied_without_signature",
ref: "docker/dockerfile-upstream:latest",
denyMsg: "signature is required for latest tag",
},
{
name: "dockerfile_upstream_master_allowed_with_signature_any_ref",
sig: dockerGithubBuilderSig("moby/buildkit", "refs/heads/master"),
ref: "docker/dockerfile-upstream:master",
allow: true,
},
{
name: "dockerfile_upstream_master_denied_without_signature",
ref: "docker/dockerfile-upstream:master",
denyMsg: "signature is required for master tag",
},
}
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
p := makeDefaultPolicy(t, tc.sig)
resp := runDefaultPolicyImage(t, p, tc.ref)
if tc.allow {
require.Equal(t, moby_buildkit_v1_sourcepolicy.PolicyAction_ALLOW, resp.Action)
require.Empty(t, resp.DenyMessages)
return
}
require.Equal(t, moby_buildkit_v1_sourcepolicy.PolicyAction_DENY, resp.Action)
require.Len(t, resp.DenyMessages, 1)
require.Contains(t, resp.DenyMessages[0].Message, tc.denyMsg)
})
}
}
func TestDefaultPolicySyftScannerImages(t *testing.T) {
testCases := []struct {
name string
sig *policytypes.SignatureInfo
ref string
allow bool
denyMsg string
}{
{
name: "syft_scanner_old_version_allowed_unsigned",
ref: "docker/buildkit-syft-scanner:1.9.0",
allow: true,
},
{
name: "syft_scanner_new_version_requires_signature",
ref: "docker/buildkit-syft-scanner:1.10.0",
denyMsg: "signature is required for 1.10.0 tag",
},
{
name: "syft_scanner_new_minor_version_requires_signature",
ref: "docker/buildkit-syft-scanner:1.10",
denyMsg: "signature is required for 1.10 tag",
},
{
name: "syft_scanner_new_major_version_requires_signature",
ref: "docker/buildkit-syft-scanner:1",
denyMsg: "signature is required for 1 tag",
},
{
name: "syft_scanner_new_version_allowed_with_matching_signature",
sig: dockerGithubBuilderSig("docker/buildkit-syft-scanner", "refs/tags/1.10.0"),
ref: "docker/buildkit-syft-scanner:1.10.0",
allow: true,
},
{
name: "syft_scanner_new_minor_version_allowed_with_matching_patch_signature",
sig: dockerGithubBuilderSig("docker/buildkit-syft-scanner", "refs/tags/1.10.0"),
ref: "docker/buildkit-syft-scanner:1.10",
allow: true,
},
{
name: "syft_scanner_new_major_version_allowed_with_matching_minor_signature",
sig: dockerGithubBuilderSig("docker/buildkit-syft-scanner", "refs/tags/1.10.0"),
ref: "docker/buildkit-syft-scanner:1",
allow: true,
},
{
name: "syft_scanner_new_version_denied_with_wrong_signature_repo",
sig: dockerGithubBuilderSig("moby/buildkit", "refs/tags/1.10.0"),
ref: "docker/buildkit-syft-scanner:1.10.0",
denyMsg: "signature is required for 1.10.0 tag",
},
{
name: "syft_scanner_new_version_denied_with_mismatched_ref",
sig: dockerGithubBuilderSig("docker/buildkit-syft-scanner", "refs/tags/1.11.0"),
ref: "docker/buildkit-syft-scanner:1.10.0",
denyMsg: "signature is required for 1.10.0 tag",
},
{
name: "syft_scanner_new_minor_version_denied_with_newer_patch_ref",
sig: dockerGithubBuilderSig("docker/buildkit-syft-scanner", "refs/tags/1.11.0"),
ref: "docker/buildkit-syft-scanner:1.10",
denyMsg: "signature is required for 1.10 tag",
},
{
name: "syft_scanner_latest_allowed_with_signature_any_ref",
sig: dockerGithubBuilderSig("docker/buildkit-syft-scanner", "refs/tags/1.10.0"),
ref: "docker/buildkit-syft-scanner:latest",
allow: true,
},
{
name: "syft_scanner_latest_denied_without_signature",
ref: "docker/buildkit-syft-scanner:latest",
denyMsg: "signature is required for latest tag",
},
}
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
p := makeDefaultPolicy(t, tc.sig)
resp := runDefaultPolicyImage(t, p, tc.ref)
if tc.allow {
require.Equal(t, moby_buildkit_v1_sourcepolicy.PolicyAction_ALLOW, resp.Action)
require.Empty(t, resp.DenyMessages)
return
}
require.Equal(t, moby_buildkit_v1_sourcepolicy.PolicyAction_DENY, resp.Action)
require.Len(t, resp.DenyMessages, 1)
require.Contains(t, resp.DenyMessages[0].Message, tc.denyMsg)
})
}
}