test: pin agent configuration hashes and evidence seeds

AGENTS.md

@@ -114,6 +114,8 @@ change here must keep working with them.
   and `_policy_data_digest`.
 - **The agent never computes artifact digests.** It passes each evaluation's policy
   directory, input and policy data through to the API, which canonicalises and hashes them.
+- **Evidence identity.** `policy-manager`'s `newEvidence` seed is every evidence stream's UUID, and plugins in the
+  field compute it. Never change it. The golden test in `policy-manager/evidence_seed_test.go` pins the UUIDs.
 - **Storage failure doesn't drop evidence.** If artifact storage fails, the evidence is still
   sent, without digests.
 - **OCI policy bundles.** The agent evaluates the extracted `policies/` subdirectory, and that

cmd/config_golden_test.go

@@ -0,0 +1,157 @@
+package cmd
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/spf13/viper"
+)
+
+// goldenHashFixtures are config files whose agentConfigurationHash was recorded BEFORE the
+// declared/runtime config refactor (agent-remote-config G0). The hash feeds the `_agent`
+// evidence label fallback and the agent evidence UUID, so it must stay byte-identical.
+var goldenHashFixtures = []struct {
+	name string
+	yaml string
+	env  map[string]string
+	hash string
+}{
+	{
+		name: "minimal",
+		yaml: `
+api:
+  url: http://localhost:8080
+`,
+		hash: "4f6b1c9d4fc55c1b99e6b9c60ef0b3783d6ca57fdccc4ca4a768a4256a72e842",
+	},
+	{
+		name: "single plugin defaults",
+		yaml: `
+api:
+  url: http://localhost:8080
+plugins:
+  ssh:
+    source: ghcr.io/compliance-framework/plugin-ssh:v1
+`,
+		hash: "9513a410fcb588cbf62934306061dbc1c3c2a236b1727dacdfef7f02d110bb2a",
+	},
+	{
+		name: "full plugin",
+		yaml: `
+daemon: true
+verbosity: 1
+api:
+  url: http://localhost:8080
+  auth:
+    client_id: 123e4567-e89b-12d3-a456-426614174000
+    client_secret: s3cret
+agent_evidence:
+  enabled: true
+  emit_on_run_completion: false
+  interval: 90m
+plugins:
+  ssh:
+    source: ghcr.io/compliance-framework/plugin-ssh:v1
+    schedule: "*/5 * * * *"
+    protocol_version: 2
+    policies:
+      - ghcr.io/compliance-framework/plugin-ssh-policies:v1
+      - ./local-policies
+    config:
+      host: 127.0.0.1
+      port: 22
+      collect_ip_allow_list: false
+      account_id: 123456789012
+    labels:
+      team: platform
+      env: prod
+    policy_data:
+      max_auth_tries: 3
+      nested:
+        allowed: [a, b]
+    policy_behavior:
+      deny: [warn]
+  github:
+    source: ghcr.io/compliance-framework/plugin-github:v1
+    config:
+      token: plain-token
+`,
+		hash: "b3bf4cf694f2aebeeac36762b1a7f4eb89288a9275b7994e99fb2f85183da1c2",
+	},
+	{
+		name: "env sourced plugin config",
+		yaml: `
+api:
+  url: http://localhost:8080
+plugins:
+  github:
+    source: ghcr.io/compliance-framework/plugin-github:v1
+    config:
+      token: from-file
+`,
+		env:  map[string]string{"CCF_PLUGINS_GITHUB_CONFIG_TOKEN": "from-env"},
+		hash: "402b411f87e7d4ab32e3148317fc24e01e98347451b1e5af5bceaa5a29cc4175",
+	},
+	{
+		name: "agent evidence disabled",
+		yaml: `
+api:
+  url: http://localhost:8080
+agent_evidence:
+  enabled: false
+plugins:
+  a:
+    source: ./plugin-a
+    protocol_version: 1
+  b:
+    source: ./plugin-b
+    schedule: "@hourly"
+`,
+		hash: "40d4e852545aad49f8aad499df08051195b10b7c91cb1013c2bc19f6388ead82",
+	},
+}
+
+// loadGoldenFixture loads a fixture through the agent's file loader. It is the only line that
+// changes when the loader is refactored.
+func loadGoldenFixture(t *testing.T, yaml string) *agentConfig {
+	t.Helper()
+	path := filepath.Join(t.TempDir(), "config.yaml")
+	if err := os.WriteFile(path, []byte(yaml), 0o600); err != nil {
+		t.Fatalf("write fixture: %v", err)
+	}
+	v := newGoldenViper(t, path)
+	config, err := loadConfig(AgentCmd(), v)
+	if err != nil {
+		t.Fatalf("load fixture: %v", err)
+	}
+	return config
+}
+
+func TestAgentConfigurationHashGolden(t *testing.T) {
+	for _, fx := range goldenHashFixtures {
+		t.Run(fx.name, func(t *testing.T) {
+			for k, v := range fx.env {
+				t.Setenv(k, v)
+			}
+			config := loadGoldenFixture(t, fx.yaml)
+			if got := agentConfigurationHash(config); got != fx.hash {
+				t.Fatalf("agentConfigurationHash changed: got %s want %s", got, fx.hash)
+			}
+		})
+	}
+}
+
+func newGoldenViper(t *testing.T, path string) *viper.Viper {
+	t.Helper()
+	v := viper.New()
+	v.SetConfigFile(path)
+	v.SetEnvPrefix("CCF")
+	v.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
+	v.AutomaticEnv()
+	if err := bindAgentEnv(v); err != nil {
+		t.Fatalf("bind env: %v", err)
+	}
+	return v
+}

policy-manager/evidence_seed_test.go

@@ -0,0 +1,47 @@
+package policy_manager
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// TestEvidenceSeedIsUnchanged pins the evidence UUIDs plugins in the field produce for
+// several label and path combinations. Every evidence stream depends on them: they must
+// never change.
+func TestEvidenceSeedIsUnchanged(t *testing.T) {
+	const (
+		// vendorPath is the policy path an OCI bundle is passed as: relative to the agent's
+		// working directory, with the repository and tag.
+		vendorPath = ".compliance-framework/policies/compliance-framework/plugin-local-ssh-policies/v0.2.0/policies"
+		// localPath is a local policy source, passed as configured.
+		localPath = "/etc/ccf/policies/ssh"
+	)
+	sshLabels := func(policyPath string) map[string]string {
+		return map[string]string{"type": "ssh", "hostname": "web-1", "_policy_path": policyPath}
+	}
+	cases := []struct {
+		name      string
+		labels    map[string]string
+		file, pkg string
+		want      string
+	}{
+		{"relative OCI path", sshLabels(vendorPath), vendorPath + "/ssh_deny_password_auth.rego", "data.compliance_framework.ssh_deny_password_auth", "cede5222-a458-4465-8134-c3751575cdd9"},
+		{"absolute path, nested file", sshLabels(localPath), localPath + "/banner/banner.rego", "data.compliance_framework.banner", "0c0ee58a-50ca-45f1-98d3-0f9602f24101"},
+		{"no _policy_path label", map[string]string{"_plugin": "test-plugin"}, "test.rego", "data.compliance_framework.no_policy_path", "271009cd-7758-432e-8869-84fa710b0f5a"},
+		{"no labels", nil, "policies/a.rego", "data.compliance_framework.a", "9eb28e96-4f5a-416a-9623-62430b8e089f"},
+		{"trailing slash", map[string]string{"type": "k8s", "_policy_path": "policies/", "cluster": "prod"}, "policies/a.rego", "data.compliance_framework.a", "98fc06e7-b1a4-4d83-a272-df4fdd75d06c"},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			p := &PolicyProcessor{labels: tc.labels}
+			e, err := p.newEvidence(Result{
+				Policy:     Policy{File: tc.file, Package: Package(tc.pkg)},
+				EvalOutput: &EvalOutput{Title: Pointer("t")},
+			}, nil)
+			require.NoError(t, err)
+			assert.Equal(t, tc.want, e.UUID)
+		})
+	}
+}