plugin/sign: a plugin that signs zone (#2993)

* plugin/sign: a plugin that signs zones Sign is a plugin that signs zone data (on disk). The README.md details what exactly happens to should be accurate related to the code. Signs are signed with a CSK, resigning and first time signing is all handled by *sign* plugin. Logging with a test zone looks something like this: ~~~ txt [INFO] plugin/sign: Signing "miek.nl." because open plugin/sign/testdata/db.miek.nl.signed: no such file or directory [INFO] plugin/sign: Signed "miek.nl." with key tags "59725" in 11.670985ms, saved in "plugin/sign/testdata/db.miek.nl.signed". Next: 2019-07-20T15:49:06.560Z [INFO] plugin/file: Successfully reloaded zone "miek.nl." in "plugin/sign/testdata/db.miek.nl.signed" with serial 1563636548 [INFO] plugin/sign: Signing "miek.nl." because resign was: 10m0s ago [INFO] plugin/sign: Signed "miek.nl." with key tags "59725" in 2.055895ms, saved in "plugin/sign/testdata/db.miek.nl.signed". Next: 2019-07-20T16:09:06.560Z [INFO] plugin/file: Successfully reloaded zone "miek.nl." in "plugin/sign/testdata/db.miek.nl.signed" with serial 1563637748 ~~~ Signed-off-by: Miek Gieben <miek@miek.nl> * Adjust readme and remove timestamps Signed-off-by: Miek Gieben <miek@miek.nl> * Comment on the newline Signed-off-by: Miek Gieben <miek@miek.nl> * Update plugin/sign/README.md Co-Authored-By: Michael Grosser <development@stp-ip.net>
2025-11-01 02:33:14 -04:00 · 2019-08-29 15:41:59 +01:00
parent eec24cb013
commit b8a0b52a5e
21 changed files with 1114 additions and 1 deletions
--- a/plugin/sign/file.go
+++ b/plugin/sign/file.go
@@ -0,0 +1,93 @@
+package sign
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/coredns/coredns/plugin/file"
+	"github.com/coredns/coredns/plugin/file/tree"
+
+	"github.com/miekg/dns"
+)
+
+// write writes out the zone file to a temporary file which is then moved into the correct place.
+func (s *Signer) write(z *file.Zone) error {
+	f, err := ioutil.TempFile(s.directory, "signed-")
+	if err != nil {
+		return err
+	}
+
+	if err := write(f, z); err != nil {
+		f.Close()
+		return err
+	}
+
+	f.Close()
+	return os.Rename(f.Name(), filepath.Join(s.directory, s.signedfile))
+}
+
+func write(w io.Writer, z *file.Zone) error {
+	if _, err := io.WriteString(w, z.Apex.SOA.String()); err != nil {
+		return err
+	}
+	w.Write([]byte("\n")) // RR Stringer() method doesn't include newline, which ends the RR in a zone file, write that here.
+	for _, rr := range z.Apex.SIGSOA {
+		io.WriteString(w, rr.String())
+		w.Write([]byte("\n"))
+	}
+	for _, rr := range z.Apex.NS {
+		io.WriteString(w, rr.String())
+		w.Write([]byte("\n"))
+	}
+	for _, rr := range z.Apex.SIGNS {
+		io.WriteString(w, rr.String())
+		w.Write([]byte("\n"))
+	}
+	err := z.Walk(func(e *tree.Elem, _ map[uint16][]dns.RR) error {
+		for _, r := range e.All() {
+			io.WriteString(w, r.String())
+			w.Write([]byte("\n"))
+		}
+		return nil
+	})
+	return err
+}
+
+// Parse parses the zone in filename and returns a new Zone or an error. This
+// is similar to the Parse function in the *file* plugin. However when parsing
+// the record types DNSKEY, RRSIG, CDNSKEY and CDS are *not* included in the returned
+// zone (if encountered).
+func Parse(f io.Reader, origin, fileName string) (*file.Zone, error) {
+	zp := dns.NewZoneParser(f, dns.Fqdn(origin), fileName)
+	zp.SetIncludeAllowed(true)
+	z := file.NewZone(origin, fileName)
+	seenSOA := false
+
+	for rr, ok := zp.Next(); ok; rr, ok = zp.Next() {
+		if err := zp.Err(); err != nil {
+			return nil, err
+		}
+
+		switch rr.(type) {
+		case *dns.DNSKEY, *dns.RRSIG, *dns.CDNSKEY, *dns.CDS:
+			continue
+		case *dns.SOA:
+			seenSOA = true
+			if err := z.Insert(rr); err != nil {
+				return nil, err
+			}
+		default:
+			if err := z.Insert(rr); err != nil {
+				return nil, err
+			}
+		}
+	}
+	if !seenSOA {
+		return nil, fmt.Errorf("file %q has no SOA record", fileName)
+	}
+
+	return z, nil
+}