lego/providers/dns/gandi/gandi.go
Ludovic Fernandez c4bbb4b819
Review DNS providers. (#565)
* refactor: review DNS providers.
2018-06-11 17:32:50 +02:00

499 lines
12 KiB
Go

// Package gandi implements a DNS provider for solving the DNS-01
// challenge using Gandi DNS.
package gandi
import (
"bytes"
"encoding/xml"
"fmt"
"io"
"io/ioutil"
"net/http"
"strings"
"sync"
"time"
"github.com/xenolf/lego/acme"
"github.com/xenolf/lego/platform/config/env"
)
// Gandi API reference: http://doc.rpc.gandi.net/index.html
// Gandi API domain examples: http://doc.rpc.gandi.net/domain/faq.html
var (
// endpoint is the Gandi XML-RPC endpoint used by Present and
// CleanUp. It is overridden during tests.
endpoint = "https://rpc.gandi.net/xmlrpc/"
// findZoneByFqdn determines the DNS zone of an fqdn. It is overridden
// during tests.
findZoneByFqdn = acme.FindZoneByFqdn
)
// inProgressInfo contains information about an in-progress challenge
type inProgressInfo struct {
zoneID int // zoneID of gandi zone to restore in CleanUp
newZoneID int // zoneID of temporary gandi zone containing TXT record
authZone string // the domain name registered at gandi with trailing "."
}
// DNSProvider is an implementation of the
// acme.ChallengeProviderTimeout interface that uses Gandi's XML-RPC
// API to manage TXT records for a domain.
type DNSProvider struct {
apiKey string
inProgressFQDNs map[string]inProgressInfo
inProgressAuthZones map[string]struct{}
inProgressMu sync.Mutex
}
// NewDNSProvider returns a DNSProvider instance configured for Gandi.
// Credentials must be passed in the environment variable: GANDI_API_KEY.
func NewDNSProvider() (*DNSProvider, error) {
values, err := env.Get("GANDI_API_KEY")
if err != nil {
return nil, fmt.Errorf("GandiDNS: %v", err)
}
return NewDNSProviderCredentials(values["GANDI_API_KEY"])
}
// NewDNSProviderCredentials uses the supplied credentials to return a
// DNSProvider instance configured for Gandi.
func NewDNSProviderCredentials(apiKey string) (*DNSProvider, error) {
if apiKey == "" {
return nil, fmt.Errorf("No Gandi API Key given")
}
return &DNSProvider{
apiKey: apiKey,
inProgressFQDNs: make(map[string]inProgressInfo),
inProgressAuthZones: make(map[string]struct{}),
}, nil
}
// Present creates a TXT record using the specified parameters. It
// does this by creating and activating a new temporary Gandi DNS
// zone. This new zone contains the TXT record.
func (d *DNSProvider) Present(domain, token, keyAuth string) error {
fqdn, value, ttl := acme.DNS01Record(domain, keyAuth)
if ttl < 300 {
ttl = 300 // 300 is gandi minimum value for ttl
}
// find authZone and Gandi zone_id for fqdn
authZone, err := findZoneByFqdn(fqdn, acme.RecursiveNameservers)
if err != nil {
return fmt.Errorf("Gandi DNS: findZoneByFqdn failure: %v", err)
}
zoneID, err := d.getZoneID(authZone)
if err != nil {
return err
}
// determine name of TXT record
if !strings.HasSuffix(
strings.ToLower(fqdn), strings.ToLower("."+authZone)) {
return fmt.Errorf(
"Gandi DNS: unexpected authZone %s for fqdn %s", authZone, fqdn)
}
name := fqdn[:len(fqdn)-len("."+authZone)]
// acquire lock and check there is not a challenge already in
// progress for this value of authZone
d.inProgressMu.Lock()
defer d.inProgressMu.Unlock()
if _, ok := d.inProgressAuthZones[authZone]; ok {
return fmt.Errorf(
"Gandi DNS: challenge already in progress for authZone %s",
authZone)
}
// perform API actions to create and activate new gandi zone
// containing the required TXT record
newZoneName := fmt.Sprintf(
"%s [ACME Challenge %s]",
acme.UnFqdn(authZone), time.Now().Format(time.RFC822Z))
newZoneID, err := d.cloneZone(zoneID, newZoneName)
if err != nil {
return err
}
newZoneVersion, err := d.newZoneVersion(newZoneID)
if err != nil {
return err
}
err = d.addTXTRecord(newZoneID, newZoneVersion, name, value, ttl)
if err != nil {
return err
}
err = d.setZoneVersion(newZoneID, newZoneVersion)
if err != nil {
return err
}
err = d.setZone(authZone, newZoneID)
if err != nil {
return err
}
// save data necessary for CleanUp
d.inProgressFQDNs[fqdn] = inProgressInfo{
zoneID: zoneID,
newZoneID: newZoneID,
authZone: authZone,
}
d.inProgressAuthZones[authZone] = struct{}{}
return nil
}
// CleanUp removes the TXT record matching the specified
// parameters. It does this by restoring the old Gandi DNS zone and
// removing the temporary one created by Present.
func (d *DNSProvider) CleanUp(domain, token, keyAuth string) error {
fqdn, _, _ := acme.DNS01Record(domain, keyAuth)
// acquire lock and retrieve zoneID, newZoneID and authZone
d.inProgressMu.Lock()
defer d.inProgressMu.Unlock()
if _, ok := d.inProgressFQDNs[fqdn]; !ok {
// if there is no cleanup information then just return
return nil
}
zoneID := d.inProgressFQDNs[fqdn].zoneID
newZoneID := d.inProgressFQDNs[fqdn].newZoneID
authZone := d.inProgressFQDNs[fqdn].authZone
delete(d.inProgressFQDNs, fqdn)
delete(d.inProgressAuthZones, authZone)
// perform API actions to restore old gandi zone for authZone
err := d.setZone(authZone, zoneID)
if err != nil {
return err
}
return d.deleteZone(newZoneID)
}
// Timeout returns the values (40*time.Minute, 60*time.Second) which
// are used by the acme package as timeout and check interval values
// when checking for DNS record propagation with Gandi.
func (d *DNSProvider) Timeout() (timeout, interval time.Duration) {
return 40 * time.Minute, 60 * time.Second
}
// types for XML-RPC method calls and parameters
type param interface {
param()
}
type paramString struct {
XMLName xml.Name `xml:"param"`
Value string `xml:"value>string"`
}
type paramInt struct {
XMLName xml.Name `xml:"param"`
Value int `xml:"value>int"`
}
type structMember interface {
structMember()
}
type structMemberString struct {
Name string `xml:"name"`
Value string `xml:"value>string"`
}
type structMemberInt struct {
Name string `xml:"name"`
Value int `xml:"value>int"`
}
type paramStruct struct {
XMLName xml.Name `xml:"param"`
StructMembers []structMember `xml:"value>struct>member"`
}
func (p paramString) param() {}
func (p paramInt) param() {}
func (m structMemberString) structMember() {}
func (m structMemberInt) structMember() {}
func (p paramStruct) param() {}
type methodCall struct {
XMLName xml.Name `xml:"methodCall"`
MethodName string `xml:"methodName"`
Params []param `xml:"params"`
}
// types for XML-RPC responses
type response interface {
faultCode() int
faultString() string
}
type responseFault struct {
FaultCode int `xml:"fault>value>struct>member>value>int"`
FaultString string `xml:"fault>value>struct>member>value>string"`
}
func (r responseFault) faultCode() int { return r.FaultCode }
func (r responseFault) faultString() string { return r.FaultString }
type responseStruct struct {
responseFault
StructMembers []struct {
Name string `xml:"name"`
ValueInt int `xml:"value>int"`
} `xml:"params>param>value>struct>member"`
}
type responseInt struct {
responseFault
Value int `xml:"params>param>value>int"`
}
type responseBool struct {
responseFault
Value bool `xml:"params>param>value>boolean"`
}
// POSTing/Marshalling/Unmarshalling
type rpcError struct {
faultCode int
faultString string
}
func (e rpcError) Error() string {
return fmt.Sprintf(
"Gandi DNS: RPC Error: (%d) %s", e.faultCode, e.faultString)
}
func httpPost(url string, bodyType string, body io.Reader) ([]byte, error) {
client := http.Client{Timeout: 60 * time.Second}
resp, err := client.Post(url, bodyType, body)
if err != nil {
return nil, fmt.Errorf("Gandi DNS: HTTP Post Error: %v", err)
}
defer resp.Body.Close()
b, err := ioutil.ReadAll(resp.Body)
if err != nil {
return nil, fmt.Errorf("Gandi DNS: HTTP Post Error: %v", err)
}
return b, nil
}
// rpcCall makes an XML-RPC call to Gandi's RPC endpoint by
// marshalling the data given in the call argument to XML and sending
// that via HTTP Post to Gandi. The response is then unmarshalled into
// the resp argument.
func rpcCall(call *methodCall, resp response) error {
// marshal
b, err := xml.MarshalIndent(call, "", " ")
if err != nil {
return fmt.Errorf("Gandi DNS: Marshal Error: %v", err)
}
// post
b = append([]byte(`<?xml version="1.0"?>`+"\n"), b...)
respBody, err := httpPost(endpoint, "text/xml", bytes.NewReader(b))
if err != nil {
return err
}
// unmarshal
err = xml.Unmarshal(respBody, resp)
if err != nil {
return fmt.Errorf("Gandi DNS: Unmarshal Error: %v", err)
}
if resp.faultCode() != 0 {
return rpcError{
faultCode: resp.faultCode(), faultString: resp.faultString()}
}
return nil
}
// functions to perform API actions
func (d *DNSProvider) getZoneID(domain string) (int, error) {
resp := &responseStruct{}
err := rpcCall(&methodCall{
MethodName: "domain.info",
Params: []param{
paramString{Value: d.apiKey},
paramString{Value: domain},
},
}, resp)
if err != nil {
return 0, err
}
var zoneID int
for _, member := range resp.StructMembers {
if member.Name == "zone_id" {
zoneID = member.ValueInt
}
}
if zoneID == 0 {
return 0, fmt.Errorf(
"Gandi DNS: Could not determine zone_id for %s", domain)
}
return zoneID, nil
}
func (d *DNSProvider) cloneZone(zoneID int, name string) (int, error) {
resp := &responseStruct{}
err := rpcCall(&methodCall{
MethodName: "domain.zone.clone",
Params: []param{
paramString{Value: d.apiKey},
paramInt{Value: zoneID},
paramInt{Value: 0},
paramStruct{
StructMembers: []structMember{
structMemberString{
Name: "name",
Value: name,
}},
},
},
}, resp)
if err != nil {
return 0, err
}
var newZoneID int
for _, member := range resp.StructMembers {
if member.Name == "id" {
newZoneID = member.ValueInt
}
}
if newZoneID == 0 {
return 0, fmt.Errorf("Gandi DNS: Could not determine cloned zone_id")
}
return newZoneID, nil
}
func (d *DNSProvider) newZoneVersion(zoneID int) (int, error) {
resp := &responseInt{}
err := rpcCall(&methodCall{
MethodName: "domain.zone.version.new",
Params: []param{
paramString{Value: d.apiKey},
paramInt{Value: zoneID},
},
}, resp)
if err != nil {
return 0, err
}
if resp.Value == 0 {
return 0, fmt.Errorf("Gandi DNS: Could not create new zone version")
}
return resp.Value, nil
}
func (d *DNSProvider) addTXTRecord(zoneID int, version int, name string, value string, ttl int) error {
resp := &responseStruct{}
err := rpcCall(&methodCall{
MethodName: "domain.zone.record.add",
Params: []param{
paramString{Value: d.apiKey},
paramInt{Value: zoneID},
paramInt{Value: version},
paramStruct{
StructMembers: []structMember{
structMemberString{
Name: "type",
Value: "TXT",
}, structMemberString{
Name: "name",
Value: name,
}, structMemberString{
Name: "value",
Value: value,
}, structMemberInt{
Name: "ttl",
Value: ttl,
}},
},
},
}, resp)
return err
}
func (d *DNSProvider) setZoneVersion(zoneID int, version int) error {
resp := &responseBool{}
err := rpcCall(&methodCall{
MethodName: "domain.zone.version.set",
Params: []param{
paramString{Value: d.apiKey},
paramInt{Value: zoneID},
paramInt{Value: version},
},
}, resp)
if err != nil {
return err
}
if !resp.Value {
return fmt.Errorf("Gandi DNS: could not set zone version")
}
return nil
}
func (d *DNSProvider) setZone(domain string, zoneID int) error {
resp := &responseStruct{}
err := rpcCall(&methodCall{
MethodName: "domain.zone.set",
Params: []param{
paramString{Value: d.apiKey},
paramString{Value: domain},
paramInt{Value: zoneID},
},
}, resp)
if err != nil {
return err
}
var respZoneID int
for _, member := range resp.StructMembers {
if member.Name == "zone_id" {
respZoneID = member.ValueInt
}
}
if respZoneID != zoneID {
return fmt.Errorf(
"Gandi DNS: Could not set new zone_id for %s", domain)
}
return nil
}
func (d *DNSProvider) deleteZone(zoneID int) error {
resp := &responseBool{}
err := rpcCall(&methodCall{
MethodName: "domain.zone.delete",
Params: []param{
paramString{Value: d.apiKey},
paramInt{Value: zoneID},
},
}, resp)
if err != nil {
return err
}
if !resp.Value {
return fmt.Errorf("Gandi DNS: could not delete zone_id")
}
return nil
}