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Fix leading serial number zeroes not being included in the database #245

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Aug 10, 2017
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17 changes: 16 additions & 1 deletion certificate/certificate.go
Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@ import (
"crypto/sha1"
"crypto/sha256"
"crypto/x509"
"encoding/asn1"
"encoding/base64"
"fmt"
"log"
Expand Down Expand Up @@ -458,7 +459,21 @@ func CertToStored(cert *x509.Certificate, parentSignature, domain, ip string, TS
stored.IPs = make([]string, 0)

stored.Version = cert.Version
stored.Serial = fmt.Sprintf("%X", cert.SerialNumber)

// Compute the ASN1 representation of the serial number
m, err := asn1.Marshal(cert.SerialNumber)
if err != nil {
stored.Serial = ""
}
// Unmarshal the ASN1 representation into a RawValue so we can trim
// the ASN1 tag and length
var rawValue asn1.RawValue
_, err = asn1.Unmarshal(m, &rawValue)
if err != nil {
stored.Serial = ""
}
stored.Serial = fmt.Sprintf("%X", rawValue.Bytes)

stored.SignatureAlgorithm = SignatureAlgorithm[cert.SignatureAlgorithm]

stored.Key, err = getPublicKeyInfo(cert)
Expand Down
188 changes: 188 additions & 0 deletions tools/fixserialnumber.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,188 @@
package main

import (
"crypto/x509"
"encoding/asn1"
"encoding/base64"
"flag"
"fmt"
"log"
"math"
"os"

"github.com/mozilla/tls-observatory/database"
)

type job struct {
id int64
// Needs to be *string because apparently serial numbers can be NULL in the db
currentSerialNumber *string
cert *x509.Certificate
}

type result struct {
id int64
changed bool
err error
}

func main() {
var workerCount int
var batchSize int64
var minID int64
var maxID int64
flag.IntVar(&workerCount, "workers", 4, "Number of workers to use")
flag.Int64Var(&batchSize, "batchSize", 1000, "Batch size")
flag.Int64Var(&minID, "minID", 0, "Minimum certificate ID to modify")
flag.Int64Var(&maxID, "maxID", math.MaxInt64, "Maximum certificate ID to modify")
flag.Parse()
jobs := make(chan job, batchSize)
results := make(chan result, batchSize)

db, err := database.RegisterConnection(
os.Getenv("TLSOBS_POSTGRESDB"),
os.Getenv("TLSOBS_POSTGRESUSER"),
os.Getenv("TLSOBS_POSTGRESPASS"),
os.Getenv("TLSOBS_POSTGRES"),
"disable",
)
if err != nil {
log.Fatalf("Error connecting to database: %s", err)
}
defer db.Close()

for w := 1; w <= workerCount; w++ {
go worker(w, jobs, results, db)
}
changedCount := 0
errorCount := 0
total := 0
go func() {
for {
log.Printf("Fetching %d certificates with id > %d", batchSize, minID)
nextBatch, err := fetchNextBatchWithRetries(5, db, minID, batchSize)
if err != nil {
log.Fatalf("Error fetching next batch: %s", err)
}
if len(nextBatch) == 0 || minID >= maxID {
close(jobs)
close(results)
log.Printf("Done. %d/%d errors. %d/%d changed.", errorCount, total, changedCount, total)
return
}
total += len(nextBatch)
for _, j := range nextBatch {
jobs <- j
minID = j.id
}
}
}()
for result := range results {
if result.err != nil {
errorCount++
log.Printf("Received error for cert id %d: %s", result.id, result.err)
}
if result.changed {
changedCount++
}
}
}

func fetchNextBatchWithRetries(retries int, db *database.DB, minID int64, batchSize int64) (jobs []job, err error) {
for i := 0; i < retries; i++ {
jobs, err = fetchNextBatch(db, minID, batchSize)
if err == nil {
break
}
}
return
}

func fetchNextBatch(db *database.DB, minID int64, batchSize int64) ([]job, error) {
rows, err := db.Query(`SELECT id, serial_number, raw_cert
FROM certificates
WHERE id > $1
ORDER BY id
LIMIT $2`,
minID,
batchSize,
)
if err != nil {
log.Fatalf("Error querying database: %s", err)
}
defer rows.Close()
var jobs []job
for rows.Next() {
var j job
var b64Crt string
if err = rows.Scan(&j.id, &j.currentSerialNumber, &b64Crt); err != nil {
return nil, fmt.Errorf("Error scanning row: %s", err)
}
cert, err := b64RawCertToX509Cert(b64Crt)
if err != nil {
log.Printf("Error converting database certificate to crypto/x509 certificate: %s", err)
continue
}
j.cert = cert
jobs = append(jobs, j)
}
return jobs, nil
}

func b64RawCertToX509Cert(b64Crt string) (*x509.Certificate, error) {
rawCert, err := base64.StdEncoding.DecodeString(b64Crt)
if err != nil {
return nil, fmt.Errorf("Error b64 decoding certificate: %s", err)
}
cert, err := x509.ParseCertificate(rawCert)
if err != nil {
return nil, fmt.Errorf("Error parsing x509 certificate: %s", err)
}
return cert, nil
}

func worker(id int, jobs <-chan job, results chan result, db *database.DB) {
for j := range jobs {
correctSerialNumberBytes, err := getSerialNumberASN1Value(j.cert)
if err != nil {
results <- result{id: j.id, err: err}
continue
}
correctSerialNumber := fmt.Sprintf("%X", correctSerialNumberBytes)
if correctSerialNumber == *j.currentSerialNumber {
// Serial number is already stored correctly in the database
results <- result{id: j.id, err: nil}
continue
}
err = updateSerialNumberInDB(db, j.id, correctSerialNumber)
if err != nil {
results <- result{
id: j.id,
err: fmt.Errorf("Error updating serial number in database: %s", err),
}
continue
}
results <- result{id: j.id, err: nil, changed: true}
}
}

// getSerialNumberASN1Value returns the ASN1-encoded serial number for the given certificate, excluding the tag and length.
func getSerialNumberASN1Value(cert *x509.Certificate) ([]byte, error) {
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I think this is the function we want to move to the certificate package. I'd make it GetHexSerial and return the hexadecimal string, since this is what we always manipulate.

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Yep, done. Less duplication this way.

m, err := asn1.Marshal(cert.SerialNumber)
if err != nil {
return nil, fmt.Errorf("Error marshalling certificate's serial number: %s", err)
}
var rawValue asn1.RawValue
_, err = asn1.Unmarshal(m, &rawValue)
if err != nil {
return nil, fmt.Errorf("Error unmarshaling certificate's serial number from ASN1: %s", err)
}
return rawValue.Bytes, nil
}

func updateSerialNumberInDB(db *database.DB, id int64, correctSerialNumber string) error {
_, err := db.Exec(`UPDATE certificates
SET serial_number = $1
WHERE id = $2`, correctSerialNumber, id)
return err
}