boulder/cmd/cert-checker/main.go

278 lines
8.8 KiB
Go

// Copyright 2015 ISRG. All rights reserved
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
package main
import (
"crypto/x509"
"encoding/json"
"fmt"
"io/ioutil"
"os"
"path"
"reflect"
"runtime"
"sync"
"sync/atomic"
"time"
"github.com/letsencrypt/boulder/Godeps/_workspace/src/github.com/cactus/go-statsd-client/statsd"
"github.com/letsencrypt/boulder/Godeps/_workspace/src/github.com/codegangsta/cli"
"github.com/letsencrypt/boulder/Godeps/_workspace/src/github.com/jmhodges/clock"
gorp "github.com/letsencrypt/boulder/Godeps/_workspace/src/gopkg.in/gorp.v1"
"github.com/letsencrypt/boulder/cmd"
"github.com/letsencrypt/boulder/core"
blog "github.com/letsencrypt/boulder/log"
"github.com/letsencrypt/boulder/policy"
"github.com/letsencrypt/boulder/sa"
)
const (
good = "valid"
bad = "invalid"
filenameLayout = "20060102"
checkPeriod = time.Hour * 24 * 90
batchSize = 1000
)
type report struct {
begin time.Time
end time.Time
GoodCerts int64
BadCerts int64
Entries map[string]reportEntry
}
func (r *report) save(directory string) error {
filename := path.Join(directory, fmt.Sprintf(
"%s-%s-report.json",
r.begin.Format(filenameLayout),
r.end.Format(filenameLayout),
))
content, err := json.Marshal(r)
if err != nil {
return err
}
return ioutil.WriteFile(filename, content, os.ModePerm)
}
type reportEntry struct {
Valid bool `json:"valid"`
Problems []string `json:"problem,omitempty"`
}
type certChecker struct {
pa core.PolicyAuthority
dbMap *gorp.DbMap
certs chan core.Certificate
clock clock.Clock
rMu *sync.Mutex
issuedReport report
}
func newChecker(saDbMap *gorp.DbMap, paDbMap *gorp.DbMap, clk clock.Clock, enforceWhitelist bool, challengeTypes map[string]bool) certChecker {
pa, err := policy.NewPolicyAuthorityImpl(paDbMap, enforceWhitelist, challengeTypes)
cmd.FailOnError(err, "Failed to create PA")
c := certChecker{
pa: pa,
dbMap: saDbMap,
certs: make(chan core.Certificate, batchSize),
rMu: new(sync.Mutex),
clock: clk,
}
c.issuedReport.Entries = make(map[string]reportEntry)
return c
}
func (c *certChecker) getCerts() error {
c.issuedReport.end = c.clock.Now()
c.issuedReport.begin = c.issuedReport.end.Add(-checkPeriod)
var count int
err := c.dbMap.SelectOne(
&count,
"SELECT count(*) FROM certificates WHERE issued >= :issued",
map[string]interface{}{"issued": c.issuedReport.begin},
)
if err != nil {
return err
}
// Retrieve certs in batches of 1000 (the size of the certificate channel)
// so that we don't eat unnecessary amounts of memory and avoid the 16MB MySQL
// packet limit.
// TODO(#701): This query needs to make better use of indexes
for offset := 0; offset < count; {
var certs []core.Certificate
_, err = c.dbMap.Select(
&certs,
"SELECT * FROM certificates WHERE issued >= :issued ORDER BY issued ASC LIMIT :limit OFFSET :offset",
map[string]interface{}{"issued": c.issuedReport.begin, "limit": batchSize, "offset": offset},
)
if err != nil {
return err
}
for _, cert := range certs {
c.certs <- cert
}
offset += len(certs)
}
// Close channel so range operations won't block once the channel empties out
close(c.certs)
return nil
}
func (c *certChecker) processCerts(wg *sync.WaitGroup) {
for cert := range c.certs {
problems := c.checkCert(cert)
valid := len(problems) == 0
c.rMu.Lock()
c.issuedReport.Entries[cert.Serial] = reportEntry{
Valid: valid,
Problems: problems,
}
c.rMu.Unlock()
if !valid {
atomic.AddInt64(&c.issuedReport.BadCerts, 1)
} else {
atomic.AddInt64(&c.issuedReport.GoodCerts, 1)
}
}
wg.Done()
}
func (c *certChecker) checkCert(cert core.Certificate) (problems []string) {
// Check digests match
if cert.Digest != core.Fingerprint256(cert.DER) {
problems = append(problems, "Stored digest doesn't match certificate digest")
}
// Parse certificate
parsedCert, err := x509.ParseCertificate(cert.DER)
if err != nil {
problems = append(problems, fmt.Sprintf("Couldn't parse stored certificate: %s", err))
} else {
// Check stored serial is correct
storedSerial, err := core.StringToSerial(cert.Serial)
if err != nil {
problems = append(problems, "Stored serial is invalid")
} else if parsedCert.SerialNumber.Cmp(storedSerial) != 0 {
problems = append(problems, "Stored serial doesn't match certificate serial")
}
// Check we have the right expiration time
if !parsedCert.NotAfter.Equal(cert.Expires) {
problems = append(problems, "Stored expiration doesn't match certificate NotAfter")
}
// Check basic constraints are set
if !parsedCert.BasicConstraintsValid {
problems = append(problems, "Certificate doesn't have basic constraints set")
}
// Check the cert isn't able to sign other certificates
if parsedCert.IsCA {
problems = append(problems, "Certificate can sign other certificates")
}
// Check the cert has the correct validity period
validityPeriod := parsedCert.NotAfter.Sub(parsedCert.NotBefore)
if validityPeriod > checkPeriod {
problems = append(problems, fmt.Sprintf("Certificate has a validity period longer than %s", checkPeriod))
} else if validityPeriod < checkPeriod {
problems = append(problems, fmt.Sprintf("Certificate has a validity period shorter than %s", checkPeriod))
}
if parsedCert.NotBefore.Before(cert.Issued.Add(-6*time.Hour)) || parsedCert.NotBefore.After(cert.Issued.Add(6*time.Hour)) {
problems = append(problems, "Stored issuance date is outside of 6 hour window of certificate NotBefore")
}
// Check that the PA is still willing to issue for each name in DNSNames + CommonName
for _, name := range append(parsedCert.DNSNames, parsedCert.Subject.CommonName) {
id := core.AcmeIdentifier{Type: core.IdentifierDNS, Value: name}
if err = c.pa.WillingToIssue(id, cert.RegistrationID); err != nil {
problems = append(problems, fmt.Sprintf("Policy Authority isn't willing to issue for %s: %s", name, err))
}
}
// Check the cert has the correct key usage extensions
if !reflect.DeepEqual(parsedCert.ExtKeyUsage, []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth, x509.ExtKeyUsageClientAuth}) {
problems = append(problems, "Certificate has incorrect key usage extensions")
}
}
return problems
}
func main() {
app := cmd.NewAppShell("cert-checker", "Checks validity of certificates issued in the last 90 days")
app.App.Flags = append(app.App.Flags, cli.IntFlag{
Name: "workers",
Value: runtime.NumCPU(),
Usage: "The number of concurrent workers used to process certificates",
}, cli.StringFlag{
Name: "report-dir-path",
Usage: "The path to write a JSON report on the certificates checks to (if no path is provided the report will not be written out)",
}, cli.StringFlag{
Name: "db-connect",
Usage: "SQL URI if not provided in the configuration file",
})
app.Config = func(c *cli.Context, config cmd.Config) cmd.Config {
config.CertChecker.ReportDirectoryPath = c.GlobalString("report-dir-path")
if connect := c.GlobalString("db-connect"); connect != "" {
config.CertChecker.DBConnect = connect
}
if workers := c.GlobalInt("workers"); workers != 0 {
config.CertChecker.Workers = workers
}
return config
}
app.Action = func(c cmd.Config, stats statsd.Statter, auditlogger *blog.AuditLogger) {
// Validate PA config and set defaults if needed
cmd.FailOnError(c.PA.CheckChallenges(), "Invalid PA configuration")
c.PA.SetDefaultChallengesIfEmpty()
saDbMap, err := sa.NewDbMap(c.CertChecker.DBConnect)
cmd.FailOnError(err, "Could not connect to database")
paDbMap, err := sa.NewDbMap(c.PA.DBConnect)
cmd.FailOnError(err, "Could not connect to policy database")
checker := newChecker(saDbMap, paDbMap, clock.Default(), c.PA.EnforcePolicyWhitelist, c.PA.Challenges)
auditlogger.Info("# Getting certificates issued in the last 90 days")
// Since we grab certificates in batches we don't want this to block, when it
// is finished it will close the certificate channel which allows the range
// loops in checker.processCerts to break
go func() {
err = checker.getCerts()
cmd.FailOnError(err, "Batch retrieval of certificates failed")
}()
auditlogger.Info(fmt.Sprintf("# Processing certificates using %d workers", c.CertChecker.Workers))
wg := new(sync.WaitGroup)
for i := 0; i < c.CertChecker.Workers; i++ {
wg.Add(1)
go checker.processCerts(wg)
}
wg.Wait()
auditlogger.Info(fmt.Sprintf(
"# Finished processing certificates, sample: %d, good: %d, bad: %d",
len(checker.issuedReport.Entries),
checker.issuedReport.GoodCerts,
checker.issuedReport.BadCerts,
))
err = checker.issuedReport.save(c.CertChecker.ReportDirectoryPath)
cmd.FailOnError(err, "Couldn't save issued certificate report")
}
app.Run()
}