Updated osquery perf for #45550 (#48935)

<!-- Add the related story/sub-task/bug number, like Resolves #123, or
remove if NA -->
**Related issue:** Resolves #45550 

# Checklist for submitter

- [x] QA'd all new/changed functionality manually



<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Enhanced Windows MDM SCEP certificate simulation to track issued
certificate specs per host during check-ins.

* **Bug Fixes**
* Certificate data generation is now stably ordered and consistent
across refreshes.
* SCEP certificate processing now ignores failed installs (no
certificate) and records only valid issued cert details.

* **Testing**
* A small subset of simulated agents may withhold one SCEP certificate
to exercise verification edge cases.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

cmd/osquery-perf/agent.go

@@ -547,8 +547,15 @@ type agent struct {
 	// cache of this host's per-host certificates (the certs unique to this host, excluding the shared certs every host
 	// reports). Note that this requires a mutex even though only used in a.processQuery, that's because both the runLoop
 	// and the live query goroutines may call DistributedWrite (which calls processQuery).
-	certificatesMutex        sync.RWMutex
-	hostCertSpecs            []simulatedCert
+	certificatesMutex sync.RWMutex
+	hostCertSpecs     []simulatedCert
+	// scepCertSpecs holds the certs issued to this host during Windows MDM SCEP exchanges, keyed by the SCEP CSP
+	// unique ID so a re-issued cert replaces its predecessor.
+	scepCertSpecs map[string]simulatedCert
+	// withholdSCEPCert marks ~5% of hosts that never report their issued SCEP certs, exercising the server's SCEP
+	// verification backstop (test-only failure).
+	withholdSCEPCert bool
+
 	commonSoftwareNameSuffix string
 
 	entraIDDeviceID          string
@@ -727,6 +734,8 @@ func newAgent(
 		cachedLastOpenedAt:       make(map[string]*time.Time),
 		commonSoftwareNameSuffix: commonSoftwareNameSuffix,
 		mdmProfileFailureProb:    mdmProfileFailureProb,
+		// Every 20th host (5%) withholds its issued SCEP certs to exercise the server's verification backstop (test-only failure).
+		withholdSCEPCert: agentIndex%20 == 0,
 
 		entraIDDeviceID:          uuid.NewString(),
 		entraIDUserPrincipalName: fmt.Sprintf("fake-%s@example.com", randomString(5)),
@@ -1624,6 +1633,16 @@ func (a *agent) doWindowsMDMCheckIn(onDemand bool) (newPollInterval time.Duratio
 					continue
 				}
 				a.stats.IncrementMDMSCEPSuccess()
+				if res.Cert == nil {
+					continue
+				}
+				// Report the issued cert via the certificates detail query so the server observes the
+				// fleet-<profileUUID> renewal-ID marker and marks the SCEP profile verified. The withheld ~5% never
+				// report theirs, so the server's verification backstop fails those profiles.
+				if a.withholdSCEPCert {
+					continue
+				}
+				a.storeSCEPCertSpec(res.UniqueID, res.Cert)
 			}
 		}()
 	} else {

cmd/osquery-perf/certificates.go

@@ -2,11 +2,13 @@ package main
 
 import (
 	"crypto/sha1" //nolint:gosec
+	"crypto/x509"
 	"encoding/hex"
 	"fmt"
 	"maps"
 	// osquery-perf shares one global math/rand RNG seeded from the --seed flag so load-test runs are reproducible
 	"math/rand" //nolint:depguard
+	"slices"
 	"strings"
 	"time"
 
@@ -151,12 +153,59 @@ func (a *agent) generateCertSpecs() []simulatedCert {
 		a.churnPerHostCertSpecs()
 	}
 
-	specs := make([]simulatedCert, 0, len(sharedCerts)+len(a.hostCertSpecs))
+	specs := make([]simulatedCert, 0, len(sharedCerts)+len(a.hostCertSpecs)+len(a.scepCertSpecs))
 	specs = append(specs, sharedCerts...)
 	specs = append(specs, a.hostCertSpecs...)
+	// Include the certs issued via Windows MDM SCEP exchanges (never churned; replaced only on re-issuance). Sorted
+	// by CSP unique ID so the report order is stable across refreshes.
+	for _, id := range slices.Sorted(maps.Keys(a.scepCertSpecs)) {
+		specs = append(specs, a.scepCertSpecs[id])
+	}
 	return specs
 }
 
+// storeSCEPCertSpec records a certificate issued during a Windows MDM SCEP exchange
+func (a *agent) storeSCEPCertSpec(uniqueID string, cert *x509.Certificate) {
+	a.certificatesMutex.Lock()
+	defer a.certificatesMutex.Unlock()
+	if a.scepCertSpecs == nil {
+		a.scepCertSpecs = make(map[string]simulatedCert)
+	}
+	a.scepCertSpecs[uniqueID] = scepIssuedCertSpec(cert)
+}
+
+// scepIssuedCertSpec converts a certificate issued during a Windows MDM SCEP exchange into a simulatedCert. The
+// cert's subject carries the fleet-<profileUUID> renewal-ID marker (expanded from the profile's
+// $FLEET_VAR_SCEP_RENEWAL_ID), which the server matches on ingestion to flip the SCEP profile to verified. Reported
+// machine-scoped: osquery-perf drives SCEP CSPs on the device channel, so the cert lands in the LocalMachine store.
+func scepIssuedCertSpec(cert *x509.Certificate) simulatedCert {
+	return simulatedCert{
+		commonName:        cert.Subject.CommonName,
+		subjectCommonName: cert.Subject.CommonName,
+		subjectOrg:        firstOrEmpty(cert.Subject.Organization),
+		// Join multiple OUs with "+OU=", mirroring how osquery reports multi-OU certs
+		subjectOrgUnit:     strings.Join(cert.Subject.OrganizationalUnit, "+OU="),
+		subjectCountry:     firstOrEmpty(cert.Subject.Country),
+		issuerCommonName:   cert.Issuer.CommonName,
+		issuerOrg:          firstOrEmpty(cert.Issuer.Organization),
+		issuerCountry:      firstOrEmpty(cert.Issuer.Country),
+		keyAlgorithm:       "rsaEncryption",
+		keyStrength:        "2048",
+		keyUsage:           "Key Encipherment, Digital Signature",
+		signingAlgorithm:   cert.SignatureAlgorithm.String(),
+		serial:             cert.SerialNumber.String(),
+		notValidAfterUnix:  fmt.Sprint(cert.NotAfter.Unix()),
+		notValidBeforeUnix: fmt.Sprint(cert.NotBefore.Unix()),
+	}
+}
+
+func firstOrEmpty(vals []string) string {
+	if len(vals) == 0 {
+		return ""
+	}
+	return vals[0]
+}
+
 // newPerHostCertSpecs generates 0-10 certificates unique to this host
 func (a *agent) newPerHostCertSpecs() []simulatedCert {
 	count := rand.Intn(11) // 0..10