From ac687f284aeea8a9892d52c9a3bcd49d8574b4e2 Mon Sep 17 00:00:00 2001
From: Miek Gieben <miek@miek.nl>
Date: Sun, 9 Jan 2011 00:11:22 +0100
Subject: [PATCH] Tsig

* add some testcases for tsig
* add unpack/pack stuff -- doesn't work correctly yet
---
 resolver/resolverTsig_test.go | 49 +++++++++++++++++++++++++++++++++++
 tsig.go                       | 13 ++++++++--
 tsig_test.go                  | 18 +++++++++++--
 types.go                      |  4 ++-
 4 files changed, 79 insertions(+), 5 deletions(-)
 create mode 100644 resolver/resolverTsig_test.go

diff --git a/resolver/resolverTsig_test.go b/resolver/resolverTsig_test.go
new file mode 100644
index 00000000..2930fe0a
--- /dev/null
+++ b/resolver/resolverTsig_test.go
@@ -0,0 +1,49 @@
+package resolver
+
+import (
+	"testing"
+	"dns"
+	"fmt"
+)
+
+func TestResolverTsig(t *testing.T) {
+	res := new(Resolver)
+	ch := res.NewQuerier()
+
+	res.Servers = []string{"127.0.0.1"}
+	res.Timeout = 2
+	res.Attempts = 1
+
+	m := new(dns.Msg)
+	m.MsgHdr.RecursionDesired = true //only set this bit
+	m.Question = make([]dns.Question, 1)
+
+	// ask something
+	m.Question[0] = dns.Question{"powerdns.nl", dns.TypeDNSKEY, dns.ClassINET}
+	m.Extra = make([]dns.RR, 1)
+        m.SetId()
+
+        tsig := new(dns.RR_TSIG)
+        tsig.Hdr.Name = "miek.nl"       // for tsig this is the key's name
+        tsig.Hdr.Rrtype = dns.TypeTSIG
+        tsig.Hdr.Class = dns.ClassANY
+        tsig.Hdr.Ttl = 0
+        tsig.GenerateMAC(m, "geheim")
+        // Add it to the msg
+        m.Extra[0] = tsig
+
+
+	ch <- DnsMsg{m, nil}
+	in := <-ch
+	if in.Dns != nil {
+		if in.Dns.Rcode != dns.RcodeSuccess {
+			t.Log("Failed to get an valid answer")
+			t.Fail()
+		}
+		fmt.Printf("%v\n", in.Dns)
+	} else {
+		fmt.Printf("Failed to get a good anwer")
+	}
+	ch <- DnsMsg{nil, nil}
+	<-ch // wait for ch to close channel
+}
diff --git a/tsig.go b/tsig.go
index 28244a68..89f185f3 100644
--- a/tsig.go
+++ b/tsig.go
@@ -30,9 +30,10 @@ type tsig_generation_fmt struct {
 }
 
 // Generate the HMAC for msg. The TSIG RR is modified
-// to include the MAC and MACSize
+// to include the MAC and MACSize. Note the the msg Id must
+// be set, otherwise the MAC is not correct
 func (rr *RR_TSIG) GenerateMAC(msg *Msg, secret string) bool {
-	buf := make([]byte, 2048) // TODO(mg) bufsize!
+	buf := make([]byte, 4096) // TODO(mg) bufsize!
 	tsigbuf := new(tsig_generation_fmt)
 
 	// Fill the struct and generate the wiredata
@@ -46,11 +47,19 @@ func (rr *RR_TSIG) GenerateMAC(msg *Msg, secret string) bool {
 	tsigbuf.OtherLen = rr.OtherLen
 	tsigbuf.OtherData = rr.OtherData
 	packStruct(tsigbuf, buf, 0)
+
+        msgbuf, ok := msg.Pack()
+        if !ok {
+                return false
+        }
+        buf = append(buf, msgbuf...)
+
 	//func NewMD5(key []byte) hash.Hash
 	hmac := hmac.NewMD5([]byte(secret))
 	io.WriteString(hmac, string(buf))
 	rr.MAC = string(hmac.Sum())
         rr.MACSize = uint16(len(rr.MAC))
+        rr.OrigId = msg.MsgHdr.Id
 
 	return true
 }
diff --git a/tsig_test.go b/tsig_test.go
index ba62df72..d62081f2 100644
--- a/tsig_test.go
+++ b/tsig_test.go
@@ -2,18 +2,32 @@ package dns
 
 import (
 	"testing"
+        "fmt"
 )
 
 func TestTsig(t *testing.T) {
 	tsig := new(RR_TSIG)
-	tsig.Hdr.Name = "miek.nl"
+	tsig.Hdr.Name = "miek.nl"       // for tsig this is the key's name
 	tsig.Hdr.Rrtype = TypeTSIG
 	tsig.Hdr.Class = ClassANY
 	tsig.Hdr.Ttl = 0
 
-        ok := tsig.GenerateMAC()
+        out := new(Msg)
+        out.MsgHdr.RecursionDesired = true
+        out.Question = make([]Question, 1)
+        out.Question[0] = Question{"miek.nl", TypeSOA, ClassINET}
+
+        ok := tsig.GenerateMAC(out, "geheim")
         if !ok {
                 t.Log("Failed")
                 t.Fail()
         }
+        fmt.Printf("%v\n", tsig)
+
+        // Having the TSIG record, it must now be added to the msg
+        // in the extra section
+        out.Extra = make([]RR, 1)
+        out.Extra[0] = tsig
+
+        fmt.Printf("%v\n", out)
 }
diff --git a/types.go b/types.go
index 011b90a9..d15d99b0 100644
--- a/types.go
+++ b/types.go
@@ -543,7 +543,9 @@ func (rr *RR_TSIG) Header() *RR_Header {
 
 func (rr *RR_TSIG) String() string {
         // It has no presentation format
-	return ""
+	return rr.Hdr.String() +
+                " " + strconv.Itoa(int(rr.MACSize)) +
+                " " + rr.MAC
 }
 
 // Translate the RRSIG's incep. and expir. time to the correct date.