Add initial support for certificate bundling

This commit is contained in:
xenolf 2015-10-24 03:55:18 +02:00
parent d6f4e42b13
commit 51a95ee548
4 changed files with 113 additions and 23 deletions

View file

@ -49,6 +49,7 @@ type Client struct {
jws *jws
keyBits int
devMode bool
issuerCert []byte
solvers map[string]solver
}
@ -161,7 +162,9 @@ func (c *Client) AgreeToTOS() error {
// ObtainCertificates tries to obtain certificates from the CA server
// using the challenges it has configured. The returned certificates are
// PEM encoded byte slices.
func (c *Client) ObtainCertificates(domains []string) ([]CertificateResource, error) {
// If bundle is true, the []byte contains both the issuer certificate and
// your issued certificate as a bundle.
func (c *Client) ObtainCertificates(domains []string, bundle bool) ([]CertificateResource, error) {
logger().Print("Obtaining certificates...")
challenges := c.getChallenges(domains)
err := c.solveChallenges(challenges)
@ -171,17 +174,22 @@ func (c *Client) ObtainCertificates(domains []string) ([]CertificateResource, er
logger().Print("Validations succeeded. Getting certificates")
return c.requestCertificates(challenges)
return c.requestCertificates(challenges, bundle)
}
// RevokeCertificate takes a PEM encoded certificate and tries to revoke it at the CA.
// RevokeCertificate takes a PEM encoded certificate or bundle and tries to revoke it at the CA.
func (c *Client) RevokeCertificate(certificate []byte) error {
certBlock, err := pemDecode(certificate)
certificates, err := parsePEMBundle(certificate)
if err != nil {
return err
}
encodedCert := base64.URLEncoding.EncodeToString(certBlock.Bytes)
x509Cert := certificates[len(certificates)-1]
if x509Cert.IsCA {
return fmt.Errorf("Certificate bundle ends with a CA certificate")
}
encodedCert := base64.URLEncoding.EncodeToString(x509Cert.Raw)
jsonBytes, err := json.Marshal(revokeCertMessage{Resource: "revoke-cert", Certificate: encodedCert})
if err != nil {
@ -207,14 +215,21 @@ func (c *Client) RevokeCertificate(certificate []byte) error {
// Please be aware that this function will return a new certificate in ANY case that is not an error.
// If the server does not provide us with a new cert on a GET request to the CertURL
// this function will start a new-cert flow where a new certificate gets generated.
func (c *Client) RenewCertificate(cert CertificateResource, revokeOld bool) (CertificateResource, error) {
// If bundle is true, the []byte contains both the issuer certificate and
// your issued certificate as a bundle.
func (c *Client) RenewCertificate(cert CertificateResource, revokeOld bool, bundle bool) (CertificateResource, error) {
// Input certificate is PEM encoded. Decode it here as we may need the decoded
// cert later on in the renewal process.
x509Cert, err := pemDecodeTox509(cert.Certificate)
// cert later on in the renewal process. The input may be a bundle or a single certificate.
certificates, err := parsePEMBundle(cert.Certificate)
if err != nil {
return CertificateResource{}, err
}
x509Cert := certificates[len(certificates)-1]
if x509Cert.IsCA {
return CertificateResource{}, fmt.Errorf("[%s] Certificate bundle ends with a CA certificate", cert.Domain)
}
// This is just meant to be informal for the user.
timeLeft := x509Cert.NotAfter.Sub(time.Now().UTC())
logger().Printf("[%s] Trying to renew certificate with %d hours remaining.", cert.Domain, int(timeLeft.Hours()))
@ -243,11 +258,31 @@ func (c *Client) RenewCertificate(cert CertificateResource, revokeOld bool) (Cer
if revokeOld {
c.RevokeCertificate(cert.Certificate)
}
cert.Certificate = pemEncode(derCertificateBytes(serverCertBytes))
issuedCert := pemEncode(derCertificateBytes(serverCertBytes))
// If bundle is true, we want to return a certificate bundle.
// To do this, we need the issuer certificate.
if bundle {
// The issuer certificate link is always supplied via an "up" link
// in the response headers of a new certificate.
links := parseLinks(resp.Header["Link"])
issuerCert, err := c.getIssuerCertificate(links["up"])
if err != nil {
// If we fail to aquire the issuer cert, return the issued certificate - do not fail.
logger().Printf("[%s] Could not bundle issuer certificate.\n%v", cert.Domain, err)
cert.Certificate = issuedCert
} else {
// Success - prepend the issuer cert to the issued cert.
issuerCert = pemEncode(derCertificateBytes(issuerCert))
issuerCert = append(issuerCert, issuedCert...)
cert.Certificate = issuerCert
}
} else {
cert.Certificate = issuedCert
}
return cert, nil
}
newCerts, err := c.ObtainCertificates([]string{cert.Domain})
newCerts, err := c.ObtainCertificates([]string{cert.Domain}, bundle)
if err != nil {
return CertificateResource{}, err
}
@ -361,10 +396,10 @@ func (c *Client) getChallenges(domains []string) []*authorizationResource {
// requestCertificates iterates all granted authorizations, creates RSA private keys and CSRs.
// It then uses these to request a certificate from the CA and returns the list of successfully
// granted certificates.
func (c *Client) requestCertificates(challenges []*authorizationResource) ([]CertificateResource, error) {
func (c *Client) requestCertificates(challenges []*authorizationResource, bundle bool) ([]CertificateResource, error) {
resc, errc := make(chan CertificateResource), make(chan error)
for _, authz := range challenges {
go c.requestCertificate(authz, resc, errc)
go c.requestCertificate(authz, resc, errc, bundle)
}
var certs []CertificateResource
@ -383,13 +418,14 @@ func (c *Client) requestCertificates(challenges []*authorizationResource) ([]Cer
return certs, nil
}
func (c *Client) requestCertificate(authz *authorizationResource, result chan CertificateResource, errc chan error) {
func (c *Client) requestCertificate(authz *authorizationResource, result chan CertificateResource, errc chan error, bundle bool) {
privKey, err := generatePrivateKey(rsakey, c.keyBits)
if err != nil {
errc <- err
return
}
// TODO: should the CSR be customizable?
csr, err := generateCsr(privKey.(*rsa.PrivateKey), authz.Domain)
if err != nil {
errc <- err
@ -432,8 +468,30 @@ func (c *Client) requestCertificate(authz *authorizationResource, result chan Ce
// certificate was not ready at the time this request completed.
// Otherwise the body is the certificate.
if len(cert) > 0 {
cerRes.CertStableURL = resp.Header.Get("Content-Location")
cerRes.Certificate = pemEncode(derCertificateBytes(cert))
issuedCert := pemEncode(derCertificateBytes(cert))
// If bundle is true, we want to return a certificate bundle.
// To do this, we need the issuer certificate.
if bundle {
// The issuer certificate link is always supplied via an "up" link
// in the response headers of a new certificate.
links := parseLinks(resp.Header["Link"])
issuerCert, err := c.getIssuerCertificate(links["up"])
if err != nil {
// If we fail to aquire the issuer cert, return the issued certificate - do not fail.
logger().Printf("[%s] Could not bundle issuer certificate.\n%v", authz.Domain, err)
cerRes.Certificate = issuedCert
} else {
// Success - prepend the issuer cert to the issued cert.
issuerCert = pemEncode(derCertificateBytes(issuerCert))
issuerCert = append(issuerCert, issuedCert...)
cerRes.Certificate = issuerCert
}
} else {
cerRes.Certificate = issuedCert
}
logger().Printf("[%s] Server responded with a certificate.", authz.Domain)
result <- cerRes
return
@ -465,6 +523,33 @@ func (c *Client) requestCertificate(authz *authorizationResource, result chan Ce
}
}
// getIssuerCertificate requests the issuer certificate and caches it for
// subsequent requests.
func (c *Client) getIssuerCertificate(url string) ([]byte, error) {
logger().Printf("Requesting issuer cert from: %s", url)
if c.issuerCert != nil {
return c.issuerCert, nil
}
resp, err := http.Get(url)
if err != nil {
return nil, err
}
issuerBytes, err := ioutil.ReadAll(resp.Body)
if err != nil {
return nil, err
}
_, err = x509.ParseCertificate(issuerBytes)
if err != nil {
return nil, err
}
c.issuerCert = issuerBytes
return issuerBytes, err
}
func logResponseHeaders(resp *http.Response) {
logger().Println(resp.Status)
for k, v := range resp.Header {

View file

@ -61,6 +61,7 @@ func GetOCSPForCert(bundle []byte) ([]byte, error) {
}
// Insert it into the slice on position 0
// We want it ordered right CA -> CRT
certificates = append(certificates, nil)
copy(certificates[1:], certificates[0:])
certificates[0] = issuerCert
@ -127,6 +128,8 @@ func performECDH(priv *ecdsa.PrivateKey, pub *ecdsa.PublicKey, outLen int, label
return buffer
}
// parsePEMBundle parses a certificate bundle from top to bottom and returns
// a slice of x509 certificates. This function will error if no certificates are found.
func parsePEMBundle(bundle []byte) ([]*x509.Certificate, error) {
var certificates []*x509.Certificate

View file

@ -94,7 +94,9 @@ type revokeCertMessage struct {
// CertificateResource represents a CA issued certificate.
// PrivateKey and Certificate are both already PEM encoded
// and can be directly written to disk.
// and can be directly written to disk. Certificate may
// be a certificate bundle, depending on the options supplied
// to create it.
type CertificateResource struct {
Domain string `json:"domain"`
CertURL string `json:"certUrl"`

View file

@ -120,7 +120,7 @@ func run(c *cli.Context) {
logger().Fatal("Please specify --domains")
}
certs, err := client.ObtainCertificates(c.GlobalStringSlice("domains"))
certs, err := client.ObtainCertificates(c.GlobalStringSlice("domains"), true)
if err != nil {
logger().Fatalf("Could not obtain certificates\n\t%v", err)
}
@ -198,7 +198,7 @@ func renew(c *cli.Context) {
certRes.PrivateKey = keyBytes
certRes.Certificate = certBytes
newCert, err := client.RenewCertificate(certRes, true)
newCert, err := client.RenewCertificate(certRes, true, true)
if err != nil {
logger().Printf("%v", err)
return