Generate wildcard certificate with SANs in ACME

This commit is contained in:
NicoMen 2018-04-11 17:16:07 +02:00 committed by Traefiker Bot
parent 8168d2fdc1
commit 7109910f46
5 changed files with 271 additions and 96 deletions

View file

@ -46,9 +46,9 @@ type ACME struct {
OnHostRule bool `description:"Enable certificate generation on frontends Host rules."`
CAServer string `description:"CA server to use."`
EntryPoint string `description:"Entrypoint to proxy acme challenge to."`
DNSChallenge *acmeprovider.DNSChallenge `description:"Activate DNS-02 Challenge"`
DNSChallenge *acmeprovider.DNSChallenge `description:"Activate DNS-01 Challenge"`
HTTPChallenge *acmeprovider.HTTPChallenge `description:"Activate HTTP-01 Challenge"`
DNSProvider string `description:"Activate DNS-02 Challenge (Deprecated)"` // deprecated
DNSProvider string `description:"Activate DNS-01 Challenge (Deprecated)"` // deprecated
DelayDontCheckDNS flaeg.Duration `description:"Assume DNS propagates after a delay in seconds rather than finding and querying nameservers."` // deprecated
ACMELogging bool `description:"Enable debug logging of ACME actions."`
client *acme.Client
@ -62,20 +62,6 @@ type ACME struct {
}
func (a *ACME) init() error {
// FIXME temporary fix, waiting for https://github.com/xenolf/lego/pull/478
acme.HTTPClient = http.Client{
Transport: &http.Transport{
Proxy: http.ProxyFromEnvironment,
Dial: (&net.Dialer{
Timeout: 30 * time.Second,
KeepAlive: 30 * time.Second,
}).Dial,
TLSHandshakeTimeout: 15 * time.Second,
ResponseHeaderTimeout: 15 * time.Second,
ExpectContinueTimeout: 1 * time.Second,
},
}
if a.ACMELogging {
acme.Logger = fmtlog.New(os.Stderr, "legolog: ", fmtlog.LstdFlags)
} else {
@ -651,6 +637,7 @@ func (a *ACME) runJobs() {
// getValidDomains checks if given domain is allowed to generate a ACME certificate and return it
func (a *ACME) getValidDomains(domains []string, wildcardAllowed bool) ([]string, error) {
// Check if the domains array is empty or contains only one empty value
if len(domains) == 0 || (len(domains) == 1 && len(domains[0]) == 0) {
return nil, errors.New("unable to generate a certificate when no domain is given")
}
@ -663,15 +650,14 @@ func (a *ACME) getValidDomains(domains []string, wildcardAllowed bool) ([]string
if a.DNSChallenge == nil && len(a.DNSProvider) == 0 {
return nil, fmt.Errorf("unable to generate a wildcard certificate for domain %q : ACME needs a DNSChallenge", strings.Join(domains, ","))
}
if len(domains) > 1 {
return nil, fmt.Errorf("unable to generate a wildcard certificate for domain %q : SANs are not allowed", strings.Join(domains, ","))
if strings.HasPrefix(domains[0], "*.*") {
return nil, fmt.Errorf("unable to generate a wildcard certificate for domain %q : ACME does not allow '*.*' wildcard domain", strings.Join(domains, ","))
}
} else {
for _, san := range domains[1:] {
if strings.HasPrefix(san, "*") {
return nil, fmt.Errorf("unable to generate a certificate in ACME provider for domains %q: SANs can not be a wildcard domain", strings.Join(domains, ","))
}
}
for _, san := range domains[1:] {
if strings.HasPrefix(san, "*") {
return nil, fmt.Errorf("unable to generate a certificate for domains %q: SANs can not be a wildcard domain", strings.Join(domains, ","))
}
}
@ -710,31 +696,37 @@ func (a *ACME) deleteUnnecessaryDomains() {
keepDomain = false
}
break
} else if strings.HasPrefix(domain.Main, "*") && domain.SANs == nil {
// Check if domains can be validated by the wildcard domain
var newDomainsToCheck []string
// Check if domains can be validated by the wildcard domain
domainsMap := make(map[string]*tls.Certificate)
domainsMap[domain.Main] = &tls.Certificate{}
for _, domainProcessed := range domainToCheck.ToStrArray() {
if isDomainAlreadyChecked(domainProcessed, domainsMap) {
log.Warnf("Domain %q will not be processed by ACME because it is validated by the wildcard %q", domainProcessed, domain.Main)
continue
}
newDomainsToCheck = append(newDomainsToCheck, domainProcessed)
}
// Delete the domain if both Main and SANs can be validated by the wildcard domain
// otherwise keep the unchecked values
if newDomainsToCheck == nil {
keepDomain = false
break
}
domainToCheck.Set(newDomainsToCheck)
}
var newDomainsToCheck []string
// Check if domains can be validated by the wildcard domain
domainsMap := make(map[string]*tls.Certificate)
domainsMap[domain.Main] = &tls.Certificate{}
if len(domain.SANs) > 0 {
domainsMap[strings.Join(domain.SANs, ",")] = &tls.Certificate{}
}
for _, domainProcessed := range domainToCheck.ToStrArray() {
if idxDomain < idxDomainToCheck && isDomainAlreadyChecked(domainProcessed, domainsMap) {
// The domain is duplicated in a CN
log.Warnf("Domain %q is duplicated in the configuration or validated by the domain %v. It will be processed once.", domainProcessed, domain)
continue
} else if domain.Main != domainProcessed && strings.HasPrefix(domain.Main, "*") && types.MatchDomain(domainProcessed, domain.Main) {
// Check if a wildcard can validate the domain
log.Warnf("Domain %q will not be processed by ACME provider because it is validated by the wildcard %q", domainProcessed, domain.Main)
continue
}
newDomainsToCheck = append(newDomainsToCheck, domainProcessed)
}
// Delete the domain if both Main and SANs can be validated by the wildcard domain
// otherwise keep the unchecked values
if newDomainsToCheck == nil {
keepDomain = false
break
}
domainToCheck.Set(newDomainsToCheck)
}
if keepDomain {

View file

@ -417,11 +417,27 @@ func TestAcme_getValidDomain(t *testing.T) {
expectedDomains: nil,
},
{
desc: "unexpected SANs",
domains: []string{"*.traefik.wtf", "foo.traefik.wtf"},
desc: "unauthorized wildcard with SAN",
domains: []string{"*.*.traefik.wtf", "foo.traefik.wtf"},
dnsChallenge: &acmeprovider.DNSChallenge{},
wildcardAllowed: true,
expectedErr: "unable to generate a wildcard certificate for domain \"*.traefik.wtf,foo.traefik.wtf\" : SANs are not allowed",
expectedErr: "unable to generate a wildcard certificate for domain \"*.*.traefik.wtf,foo.traefik.wtf\" : ACME does not allow '*.*' wildcard domain",
expectedDomains: nil,
},
{
desc: "wildcard with SANs",
domains: []string{"*.traefik.wtf", "traefik.wtf"},
dnsChallenge: &acmeprovider.DNSChallenge{},
wildcardAllowed: true,
expectedErr: "",
expectedDomains: []string{"*.traefik.wtf", "traefik.wtf"},
},
{
desc: "unexpected SANs",
domains: []string{"*.traefik.wtf", "*.acme.wtf"},
dnsChallenge: &acmeprovider.DNSChallenge{},
wildcardAllowed: true,
expectedErr: "unable to generate a certificate for domains \"*.traefik.wtf,*.acme.wtf\": SANs can not be a wildcard domain",
expectedDomains: nil,
},
}

View file

@ -112,7 +112,7 @@ entryPoint = "https"
#
entryPoint = "http"
# Use a DNS-01/DNS-02 acme challenge rather than HTTP-01 challenge.
# Use a DNS-01/DNS-01 acme challenge rather than HTTP-01 challenge.
# Note : Mandatory for wildcard certificates generation.
#
# Optional
@ -264,7 +264,7 @@ defaultEntryPoints = ["http", "https"]
### `dnsChallenge`
Use `DNS-01/DNS-02` challenge to generate/renew ACME certificates.
Use `DNS-01/DNS-01` challenge to generate/renew ACME certificates.
```toml
[acme]
@ -276,7 +276,7 @@ Use `DNS-01/DNS-02` challenge to generate/renew ACME certificates.
```
!!! note
ACME wildcard certificates can only be generated thanks to a `DNS-02` challenge.
ACME wildcard certificates can only be generated thanks to a `DNS-01` challenge.
#### `provider`
@ -397,14 +397,18 @@ CA server to use.
main = "local3.com"
[[acme.domains]]
main = "*.local4.com"
sans = ["local4.com", "test1.test1.local4.com"]
# ...
```
#### Wildcard domains
Wildcard domain has to be defined as a main domain **with no SANs** (alternative domains).
Wildcard domain has to be defined as a main domain.
All domains must have A/AAAA records pointing to Træfik.
Due to ACME limitation, it's not possible to define a wildcard as a SAN (alternative domains).
It's neither possible to define a wildcard on a wildcard domain (for example `*.*.local.com`).
!!! warning
Note that Let's Encrypt has [rate limiting](https://letsencrypt.org/docs/rate-limits).
@ -435,9 +439,9 @@ Each domain & SANs will lead to a certificate request.
[ACME V2](https://community.letsencrypt.org/t/acme-v2-and-wildcard-certificate-support-is-live/55579) allows wildcard certificate support.
However, this feature needs a specific configuration.
### DNS-02 Challenge
### DNS-01 Challenge
As described in [Let's Encrypt post](https://community.letsencrypt.org/t/staging-endpoint-for-acme-v2/49605), wildcard certificates can only be generated through a `DNS-02`Challenge.
As described in [Let's Encrypt post](https://community.letsencrypt.org/t/staging-endpoint-for-acme-v2/49605), wildcard certificates can only be generated through a `DNS-01` Challenge.
This challenge is linked to the Træfik option `acme.dnsChallenge`.
```toml
@ -454,16 +458,88 @@ For more information about this option, please refer to the [dnsChallenge sectio
### Wildcard domain
Wildcard domains can currently be provided only by to the `acme.domains` option.
Theses domains can not have SANs.
```toml
[acme]
# ...
[[acme.domains]]
main = "*local1.com"
main = "*.local1.com"
sans = ["local1.com"]
[[acme.domains]]
main = "*.local2.com"
# ...
```
For more information about this option, please refer to the [domains section](/configuration/acme/#domains).
### Limitations
Let's Encrypt wildcard support have some limitations to take into account :
- Wildcard domain can not be a SAN (alternative domain),
- Wildcard domain on a wildcard domain is forbidden (for example `*.*.local.com`),
- A DNS-01 Challenge is executed for each domain (CN and SANs), DNS provider can not manage correctly this behavior as explained in the [DNS provider support section](/configuration/acme/#dns-provider-support)
### DNS provider support
All DNS providers allow creating ACME wildcard certificates.
However, many troubles can appear for wildcard domains with SANs.
If a wildcard domain is defined with it root domain as SAN, as described below, 2 DNS-01 Challenges will be executed.
```toml
[acme]
# ...
[[acme.domains]]
main = "*.local1.com"
sans = ["local1.com"]
# ...
```
When a DNS-01 Challenge is done, Let's Encrypt checks if a TXT record is created with a given name and a given value.
When a certificate is generated for a wildcard domain is defined with it root domain as SAN, the requested TXT record name for both the wildcard domain and the root domain is the same.
The [DNS RFC](https://community.letsencrypt.org/t/wildcard-issuance-two-txt-records-for-the-same-name/54528/2) allows this behavior.
But all DNS providers keep TXT records values in a cache with a TTL.
In function of the parameters given by the Træfik ACME client library ([LEGO](https://github.com/xenolf/lego)), the TXT record TTL can be superior to challenge Timeout.
In that event, the DNS-01 Challenge will not work correctly.
[LEGO](https://github.com/xenolf/lego) will involve in the way to be adapted to all of DNS providers.
Meanwhile, the table described below contains all the DNS providers supported by Træfik and indicates if they allow generating certificates for a wildcard domain and its root domain.
Do not hesitate to complete it.
| Provider Name | Provider code | Wildcard and Root Domain Support |
|--------------------------------------------------------|----------------|----------------------------------|
| [Auroradns](https://www.pcextreme.com/aurora/dns) | `auroradns` | Not tested yet |
| [Azure](https://azure.microsoft.com/services/dns/) | `azure` | Not tested yet |
| [Blue Cat](https://www.bluecatnetworks.com/) | `bluecat` | Not tested yet |
| [Cloudflare](https://www.cloudflare.com) | `cloudflare` | YES |
| [CloudXNS](https://www.cloudxns.net) | `cloudxns` | Not tested yet |
| [DigitalOcean](https://www.digitalocean.com) | `digitalocean` | YES |
| [DNSimple](https://dnsimple.com) | `dnsimple` | Not tested yet |
| [DNS Made Easy](https://dnsmadeeasy.com) | `dnsmadeeasy` | Not tested yet |
| [DNSPod](http://www.dnspod.net/) | `dnspod` | Not tested yet |
| [Duck DNS](https://www.duckdns.org/) | `duckdns` | Not tested yet |
| [Dyn](https://dyn.com) | `dyn` | Not tested yet |
| External Program | `exec` | Not tested yet |
| [Exoscale](https://www.exoscale.ch) | `exoscale` | Not tested yet |
| [Fast DNS](https://www.akamai.com/) | `fastdns` | Not tested yet |
| [Gandi](https://www.gandi.net) | `gandi` | Not tested yet |
| [Gandi V5](http://doc.livedns.gandi.net) | `gandiv5` | Not tested yet |
| [Glesys](https://glesys.com/) | `glesys` | Not tested yet |
| [GoDaddy](https://godaddy.com/domains) | `godaddy` | Not tested yet |
| [Google Cloud DNS](https://cloud.google.com/dns/docs/) | `gcloud` | YES |
| [Lightsail](https://aws.amazon.com/lightsail/) | `lightsail` | Not tested yet |
| [Linode](https://www.linode.com) | `linode` | Not tested yet |
| manual | - | YES |
| [Namecheap](https://www.namecheap.com) | `namecheap` | Not tested yet |
| [name.com](https://www.name.com/) | `namedotcom` | Not tested yet |
| [Ns1](https://ns1.com/) | `ns1` | Not tested yet |
| [Open Telekom Cloud](https://cloud.telekom.de/en/) | `otc` | Not tested yet |
| [OVH](https://www.ovh.com) | `ovh` | YES |
| [PowerDNS](https://www.powerdns.com) | `pdns` | Not tested yet |
| [Rackspace](https://www.rackspace.com/cloud/dns) | `rackspace` | Not tested yet |
| [RFC2136](https://tools.ietf.org/html/rfc2136) | `rfc2136` | Not tested yet |
| [Route 53](https://aws.amazon.com/route53/) | `route53` | YES |
| [VULTR](https://www.vultr.com) | `vultr` | Not tested yet |

View file

@ -42,7 +42,7 @@ type Configuration struct {
EntryPoint string `description:"EntryPoint to use."`
OnHostRule bool `description:"Enable certificate generation on frontends Host rules."`
OnDemand bool `description:"Enable on demand certificate generation. This will request a certificate from Let's Encrypt during the first TLS handshake for a hostname that does not yet have a certificate."` //deprecated
DNSChallenge *DNSChallenge `description:"Activate DNS-02 Challenge"`
DNSChallenge *DNSChallenge `description:"Activate DNS-01 Challenge"`
HTTPChallenge *HTTPChallenge `description:"Activate HTTP-01 Challenge"`
Domains []types.Domain `description:"CN and SANs (alternative domains) to each main domain using format: --acme.domains='main.com,san1.com,san2.com' --acme.domains='*.main.net'. No SANs for wildcards domain. Wildcard domains only accepted with DNSChallenge"`
}
@ -72,7 +72,7 @@ type Certificate struct {
// DNSChallenge contains DNS challenge Configuration
type DNSChallenge struct {
Provider string `description:"Use a DNS-02 based challenge provider rather than HTTPS."`
Provider string `description:"Use a DNS-01 based challenge provider rather than HTTPS."`
DelayBeforeCheck flaeg.Duration `description:"Assume DNS propagates after a delay in seconds rather than finding and querying nameservers."`
}
@ -565,16 +565,16 @@ func (p *Provider) getValidDomains(domain types.Domain, wildcardAllowed bool) ([
if p.DNSChallenge == nil {
return nil, fmt.Errorf("unable to generate a wildcard certificate in ACME provider for domain %q : ACME needs a DNSChallenge", strings.Join(domains, ","))
}
if len(domain.SANs) > 0 {
return nil, fmt.Errorf("unable to generate a wildcard certificate in ACME provider for domain %q : SANs are not allowed", strings.Join(domains, ","))
}
} else {
for _, san := range domain.SANs {
if strings.HasPrefix(san, "*") {
return nil, fmt.Errorf("unable to generate a certificate in ACME provider for domains %q: SANs can not be a wildcard domain", strings.Join(domains, ","))
}
if strings.HasPrefix(domain.Main, "*.*") {
return nil, fmt.Errorf("unable to generate a wildcard certificate in ACME provider for domain %q : ACME does not allow '*.*' wildcard domain", strings.Join(domains, ","))
}
}
for _, san := range domain.SANs {
if strings.HasPrefix(san, "*") {
return nil, fmt.Errorf("unable to generate a certificate in ACME provider for domains %q: SAN %q can not be a wildcard domain", strings.Join(domains, ","), san)
}
}
domains = fun.Map(types.CanonicalDomain, domains).([]string)
return domains, nil
}
@ -610,26 +610,31 @@ func (p *Provider) deleteUnnecessaryDomains() {
keepDomain = false
}
break
} else if strings.HasPrefix(domain.Main, "*") && domain.SANs == nil {
// Check if domains can be validated by the wildcard domain
var newDomainsToCheck []string
for _, domainProcessed := range domainToCheck.ToStrArray() {
if isDomainAlreadyChecked(domainProcessed, domain.ToStrArray()) {
log.Warnf("Domain %q will not be processed by ACME provider because it is validated by the wildcard %q", domainProcessed, domain.Main)
continue
}
newDomainsToCheck = append(newDomainsToCheck, domainProcessed)
}
// Delete the domain if both Main and SANs can be validated by the wildcard domain
// otherwise keep the unchecked values
if newDomainsToCheck == nil {
keepDomain = false
break
}
domainToCheck.Set(newDomainsToCheck)
}
// Check if CN or SANS to check already exists
// or can not be checked by a wildcard
var newDomainsToCheck []string
for _, domainProcessed := range domainToCheck.ToStrArray() {
if idxDomain < idxDomainToCheck && isDomainAlreadyChecked(domainProcessed, domain.ToStrArray()) {
// The domain is duplicated in a CN
log.Warnf("Domain %q is duplicated in the configuration or validated by the domain %v. It will be processed once.", domainProcessed, domain)
continue
} else if domain.Main != domainProcessed && strings.HasPrefix(domain.Main, "*") && isDomainAlreadyChecked(domainProcessed, []string{domain.Main}) {
// Check if a wildcard can validate the domain
log.Warnf("Domain %q will not be processed by ACME provider because it is validated by the wildcard %q", domainProcessed, domain.Main)
continue
}
newDomainsToCheck = append(newDomainsToCheck, domainProcessed)
}
// Delete the domain if both Main and SANs can be validated by the wildcard domain
// otherwise keep the unchecked values
if newDomainsToCheck == nil {
keepDomain = false
break
}
domainToCheck.Set(newDomainsToCheck)
}
if keepDomain {

View file

@ -207,11 +207,27 @@ func TestGetValidDomain(t *testing.T) {
expectedDomains: nil,
},
{
desc: "unexpected SANs",
domains: types.Domain{Main: "*.traefik.wtf", SANs: []string{"foo.traefik.wtf"}},
desc: "unauthorized wildcard with SAN",
domains: types.Domain{Main: "*.*.traefik.wtf", SANs: []string{"foo.traefik.wtf"}},
dnsChallenge: &DNSChallenge{},
wildcardAllowed: true,
expectedErr: "unable to generate a wildcard certificate in ACME provider for domain \"*.traefik.wtf,foo.traefik.wtf\" : SANs are not allowed",
expectedErr: "unable to generate a wildcard certificate in ACME provider for domain \"*.*.traefik.wtf,foo.traefik.wtf\" : ACME does not allow '*.*' wildcard domain",
expectedDomains: nil,
},
{
desc: "wildcard and SANs",
domains: types.Domain{Main: "*.traefik.wtf", SANs: []string{"traefik.wtf"}},
dnsChallenge: &DNSChallenge{},
wildcardAllowed: true,
expectedErr: "",
expectedDomains: []string{"*.traefik.wtf", "traefik.wtf"},
},
{
desc: "unexpected SANs",
domains: types.Domain{Main: "*.traefik.wtf", SANs: []string{"*.acme.wtf"}},
dnsChallenge: &DNSChallenge{},
wildcardAllowed: true,
expectedErr: "unable to generate a certificate in ACME provider for domains \"*.traefik.wtf,*.acme.wtf\": SAN \"*.acme.wtf\" can not be a wildcard domain",
expectedDomains: nil,
},
}
@ -251,8 +267,8 @@ func TestDeleteUnnecessaryDomains(t *testing.T) {
Main: "*.foo.acme.wtf",
},
{
Main: "acme.wtf",
SANs: []string{"traefik.acme.wtf", "bar.foo"},
Main: "acme02.wtf",
SANs: []string{"traefik.acme02.wtf", "bar.foo"},
},
},
expectedDomains: []types.Domain{
@ -262,15 +278,38 @@ func TestDeleteUnnecessaryDomains(t *testing.T) {
},
{
Main: "*.foo.acme.wtf",
SANs: []string{},
},
{
Main: "acme.wtf",
SANs: []string{"traefik.acme.wtf", "bar.foo"},
Main: "acme02.wtf",
SANs: []string{"traefik.acme02.wtf", "bar.foo"},
},
},
},
{
desc: "2 domains with same values",
desc: "wildcard and root domain",
domains: []types.Domain{
{
Main: "acme.wtf",
},
{
Main: "*.acme.wtf",
SANs: []string{"acme.wtf"},
},
},
expectedDomains: []types.Domain{
{
Main: "acme.wtf",
SANs: []string{},
},
{
Main: "*.acme.wtf",
SANs: []string{},
},
},
},
{
desc: "2 equals domains",
domains: []types.Domain{
{
Main: "acme.wtf",
@ -288,6 +327,29 @@ func TestDeleteUnnecessaryDomains(t *testing.T) {
},
},
},
{
desc: "2 domains with same values",
domains: []types.Domain{
{
Main: "acme.wtf",
SANs: []string{"traefik.acme.wtf"},
},
{
Main: "acme.wtf",
SANs: []string{"traefik.acme.wtf", "foo.bar"},
},
},
expectedDomains: []types.Domain{
{
Main: "acme.wtf",
SANs: []string{"traefik.acme.wtf"},
},
{
Main: "foo.bar",
SANs: []string{},
},
},
},
{
desc: "domain totally checked by wildcard",
domains: []types.Domain{
@ -302,6 +364,25 @@ func TestDeleteUnnecessaryDomains(t *testing.T) {
expectedDomains: []types.Domain{
{
Main: "*.acme.wtf",
SANs: []string{},
},
},
},
{
desc: "duplicated wildcard",
domains: []types.Domain{
{
Main: "*.acme.wtf",
SANs: []string{"acme.wtf"},
},
{
Main: "*.acme.wtf",
},
},
expectedDomains: []types.Domain{
{
Main: "*.acme.wtf",
SANs: []string{"acme.wtf"},
},
},
},
@ -315,6 +396,10 @@ func TestDeleteUnnecessaryDomains(t *testing.T) {
{
Main: "*.acme.wtf",
},
{
Main: "who.acme.wtf",
SANs: []string{"traefik.acme.wtf", "bar.acme.wtf"},
},
},
expectedDomains: []types.Domain{
{
@ -323,6 +408,7 @@ func TestDeleteUnnecessaryDomains(t *testing.T) {
},
{
Main: "*.acme.wtf",
SANs: []string{},
},
},
},