diff options
Diffstat (limited to 'vendor/github.com/rsc/letsencrypt/vendor/github.com/xenolf/lego/acme/dns_challenge.go')
| -rw-r--r-- | vendor/github.com/rsc/letsencrypt/vendor/github.com/xenolf/lego/acme/dns_challenge.go | 305 |
1 files changed, 0 insertions, 305 deletions
diff --git a/vendor/github.com/rsc/letsencrypt/vendor/github.com/xenolf/lego/acme/dns_challenge.go b/vendor/github.com/rsc/letsencrypt/vendor/github.com/xenolf/lego/acme/dns_challenge.go deleted file mode 100644 index 30f2170ff..000000000 --- a/vendor/github.com/rsc/letsencrypt/vendor/github.com/xenolf/lego/acme/dns_challenge.go +++ /dev/null @@ -1,305 +0,0 @@ -package acme - -import ( - "crypto/sha256" - "encoding/base64" - "errors" - "fmt" - "log" - "net" - "strings" - "time" - - "github.com/miekg/dns" - "golang.org/x/net/publicsuffix" -) - -type preCheckDNSFunc func(fqdn, value string) (bool, error) - -var ( - // PreCheckDNS checks DNS propagation before notifying ACME that - // the DNS challenge is ready. - PreCheckDNS preCheckDNSFunc = checkDNSPropagation - fqdnToZone = map[string]string{} -) - -const defaultResolvConf = "/etc/resolv.conf" - -var defaultNameservers = []string{ - "google-public-dns-a.google.com:53", - "google-public-dns-b.google.com:53", -} - -var RecursiveNameservers = getNameservers(defaultResolvConf, defaultNameservers) - -// DNSTimeout is used to override the default DNS timeout of 10 seconds. -var DNSTimeout = 10 * time.Second - -// getNameservers attempts to get systems nameservers before falling back to the defaults -func getNameservers(path string, defaults []string) []string { - config, err := dns.ClientConfigFromFile(path) - if err != nil || len(config.Servers) == 0 { - return defaults - } - - systemNameservers := []string{} - for _, server := range config.Servers { - // ensure all servers have a port number - if _, _, err := net.SplitHostPort(server); err != nil { - systemNameservers = append(systemNameservers, net.JoinHostPort(server, "53")) - } else { - systemNameservers = append(systemNameservers, server) - } - } - return systemNameservers -} - -// DNS01Record returns a DNS record which will fulfill the `dns-01` challenge -func DNS01Record(domain, keyAuth string) (fqdn string, value string, ttl int) { - keyAuthShaBytes := sha256.Sum256([]byte(keyAuth)) - // base64URL encoding without padding - keyAuthSha := base64.URLEncoding.EncodeToString(keyAuthShaBytes[:sha256.Size]) - value = strings.TrimRight(keyAuthSha, "=") - ttl = 120 - fqdn = fmt.Sprintf("_acme-challenge.%s.", domain) - return -} - -// dnsChallenge implements the dns-01 challenge according to ACME 7.5 -type dnsChallenge struct { - jws *jws - validate validateFunc - provider ChallengeProvider -} - -func (s *dnsChallenge) Solve(chlng challenge, domain string) error { - logf("[INFO][%s] acme: Trying to solve DNS-01", domain) - - if s.provider == nil { - return errors.New("No DNS Provider configured") - } - - // Generate the Key Authorization for the challenge - keyAuth, err := getKeyAuthorization(chlng.Token, s.jws.privKey) - if err != nil { - return err - } - - err = s.provider.Present(domain, chlng.Token, keyAuth) - if err != nil { - return fmt.Errorf("Error presenting token: %s", err) - } - defer func() { - err := s.provider.CleanUp(domain, chlng.Token, keyAuth) - if err != nil { - log.Printf("Error cleaning up %s: %v ", domain, err) - } - }() - - fqdn, value, _ := DNS01Record(domain, keyAuth) - - logf("[INFO][%s] Checking DNS record propagation using %+v", domain, RecursiveNameservers) - - var timeout, interval time.Duration - switch provider := s.provider.(type) { - case ChallengeProviderTimeout: - timeout, interval = provider.Timeout() - default: - timeout, interval = 60*time.Second, 2*time.Second - } - - err = WaitFor(timeout, interval, func() (bool, error) { - return PreCheckDNS(fqdn, value) - }) - if err != nil { - return err - } - - return s.validate(s.jws, domain, chlng.URI, challenge{Resource: "challenge", Type: chlng.Type, Token: chlng.Token, KeyAuthorization: keyAuth}) -} - -// checkDNSPropagation checks if the expected TXT record has been propagated to all authoritative nameservers. -func checkDNSPropagation(fqdn, value string) (bool, error) { - // Initial attempt to resolve at the recursive NS - r, err := dnsQuery(fqdn, dns.TypeTXT, RecursiveNameservers, true) - if err != nil { - return false, err - } - if r.Rcode == dns.RcodeSuccess { - // If we see a CNAME here then use the alias - for _, rr := range r.Answer { - if cn, ok := rr.(*dns.CNAME); ok { - if cn.Hdr.Name == fqdn { - fqdn = cn.Target - break - } - } - } - } - - authoritativeNss, err := lookupNameservers(fqdn) - if err != nil { - return false, err - } - - return checkAuthoritativeNss(fqdn, value, authoritativeNss) -} - -// checkAuthoritativeNss queries each of the given nameservers for the expected TXT record. -func checkAuthoritativeNss(fqdn, value string, nameservers []string) (bool, error) { - for _, ns := range nameservers { - r, err := dnsQuery(fqdn, dns.TypeTXT, []string{net.JoinHostPort(ns, "53")}, false) - if err != nil { - return false, err - } - - if r.Rcode != dns.RcodeSuccess { - return false, fmt.Errorf("NS %s returned %s for %s", ns, dns.RcodeToString[r.Rcode], fqdn) - } - - var found bool - for _, rr := range r.Answer { - if txt, ok := rr.(*dns.TXT); ok { - if strings.Join(txt.Txt, "") == value { - found = true - break - } - } - } - - if !found { - return false, fmt.Errorf("NS %s did not return the expected TXT record", ns) - } - } - - return true, nil -} - -// dnsQuery will query a nameserver, iterating through the supplied servers as it retries -// The nameserver should include a port, to facilitate testing where we talk to a mock dns server. -func dnsQuery(fqdn string, rtype uint16, nameservers []string, recursive bool) (in *dns.Msg, err error) { - m := new(dns.Msg) - m.SetQuestion(fqdn, rtype) - m.SetEdns0(4096, false) - - if !recursive { - m.RecursionDesired = false - } - - // Will retry the request based on the number of servers (n+1) - for i := 1; i <= len(nameservers)+1; i++ { - ns := nameservers[i%len(nameservers)] - udp := &dns.Client{Net: "udp", Timeout: DNSTimeout} - in, _, err = udp.Exchange(m, ns) - - if err == dns.ErrTruncated { - tcp := &dns.Client{Net: "tcp", Timeout: DNSTimeout} - // If the TCP request suceeds, the err will reset to nil - in, _, err = tcp.Exchange(m, ns) - } - - if err == nil { - break - } - } - return -} - -// lookupNameservers returns the authoritative nameservers for the given fqdn. -func lookupNameservers(fqdn string) ([]string, error) { - var authoritativeNss []string - - zone, err := FindZoneByFqdn(fqdn, RecursiveNameservers) - if err != nil { - return nil, fmt.Errorf("Could not determine the zone: %v", err) - } - - r, err := dnsQuery(zone, dns.TypeNS, RecursiveNameservers, true) - if err != nil { - return nil, err - } - - for _, rr := range r.Answer { - if ns, ok := rr.(*dns.NS); ok { - authoritativeNss = append(authoritativeNss, strings.ToLower(ns.Ns)) - } - } - - if len(authoritativeNss) > 0 { - return authoritativeNss, nil - } - return nil, fmt.Errorf("Could not determine authoritative nameservers") -} - -// FindZoneByFqdn determines the zone apex for the given fqdn by recursing up the -// domain labels until the nameserver returns a SOA record in the answer section. -func FindZoneByFqdn(fqdn string, nameservers []string) (string, error) { - // Do we have it cached? - if zone, ok := fqdnToZone[fqdn]; ok { - return zone, nil - } - - labelIndexes := dns.Split(fqdn) - for _, index := range labelIndexes { - domain := fqdn[index:] - // Give up if we have reached the TLD - if isTLD(domain) { - break - } - - in, err := dnsQuery(domain, dns.TypeSOA, nameservers, true) - if err != nil { - return "", err - } - - // Any response code other than NOERROR and NXDOMAIN is treated as error - if in.Rcode != dns.RcodeNameError && in.Rcode != dns.RcodeSuccess { - return "", fmt.Errorf("Unexpected response code '%s' for %s", - dns.RcodeToString[in.Rcode], domain) - } - - // Check if we got a SOA RR in the answer section - if in.Rcode == dns.RcodeSuccess { - for _, ans := range in.Answer { - if soa, ok := ans.(*dns.SOA); ok { - zone := soa.Hdr.Name - fqdnToZone[fqdn] = zone - return zone, nil - } - } - } - } - - return "", fmt.Errorf("Could not find the start of authority") -} - -func isTLD(domain string) bool { - publicsuffix, _ := publicsuffix.PublicSuffix(UnFqdn(domain)) - if publicsuffix == UnFqdn(domain) { - return true - } - return false -} - -// ClearFqdnCache clears the cache of fqdn to zone mappings. Primarily used in testing. -func ClearFqdnCache() { - fqdnToZone = map[string]string{} -} - -// ToFqdn converts the name into a fqdn appending a trailing dot. -func ToFqdn(name string) string { - n := len(name) - if n == 0 || name[n-1] == '.' { - return name - } - return name + "." -} - -// UnFqdn converts the fqdn into a name removing the trailing dot. -func UnFqdn(name string) string { - n := len(name) - if n != 0 && name[n-1] == '.' { - return name[:n-1] - } - return name -} |