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>

1 files changed, 43 insertions, 0 deletions

diff --git a/plugin/sign/file_test.go b/plugin/sign/file_test.go
new file mode 100644
index 000000000..72d2b02ac
--- /dev/null
+++ b/plugin/sign/file_test.go
@@ -0,0 +1,43 @@
+package sign
+
+import (
+	"os"
+	"testing"
+
+	"github.com/miekg/dns"
+)
+
+func TestFileParse(t *testing.T) {
+	f, err := os.Open("testdata/db.miek.nl")
+	if err != nil {
+		t.Fatal(err)
+	}
+	z, err := Parse(f, "miek.nl.", "testdata/db.miek.nl")
+	if err != nil {
+		t.Fatal(err)
+	}
+	s := &Signer{
+		directory:  ".",
+		signedfile: "db.miek.nl.test",
+	}
+
+	s.write(z)
+	defer os.Remove("db.miek.nl.test")
+
+	f, err = os.Open("db.miek.nl.test")
+	if err != nil {
+		t.Fatal(err)
+	}
+	z, err = Parse(f, "miek.nl.", "db.miek.nl.test")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if x := z.Apex.SOA.Header().Name; x != "miek.nl." {
+		t.Errorf("Expected SOA name to be %s, got %s", x, "miek.nl.")
+	}
+	apex, _ := z.Search("miek.nl.")
+	key := apex.Type(dns.TypeDNSKEY)
+	if key != nil {
+		t.Errorf("Expected no DNSKEYs, but got %d", len(key))
+	}
+}