From a6fee19f4cb6c20f87bf865106d817f49a89c610 Mon Sep 17 00:00:00 2001
From: Miek Gieben <miek@miek.nl>
Date: Sun, 9 Jan 2011 15:30:45 +0100
Subject: [PATCH] Fix tsig by making timeSigned a 64 bit int

only use the lower 48 bits to make it all work
---
 msg.go   | 46 ++++++++++++++++++++++------------------------
 tsig.go  | 19 +++++++++++--------
 types.go |  7 +++++++
 3 files changed, 40 insertions(+), 32 deletions(-)

diff --git a/msg.go b/msg.go
index 9cc50bfc..02b9ae65 100644
--- a/msg.go
+++ b/msg.go
@@ -244,22 +244,6 @@ func packStructValue(val *reflect.StructValue, msg []byte, off int) (off1 int, o
 		BadType:
 			fmt.Fprintf(os.Stderr, "dns: unknown packing type %v\n", f.Type)
 			return len(msg), false
-		case *reflect.ArrayValue:
-			switch f.Tag {
-			default:
-				fmt.Fprintf(os.Stderr, "dns: unknown IP tag %v", f.Tag)
-				return len(msg), false
-			case "TSIG":
-				// has a 3 byte inception time (check len?)
-				// need to do some shifting here
-				msg[off] = byte(fv.Elem(0).(*reflect.UintValue).Get() >> 8)
-				msg[off+1] = byte(fv.Elem(0).(*reflect.UintValue).Get())
-				msg[off+2] = byte(fv.Elem(1).(*reflect.UintValue).Get() >> 8)
-				msg[off+3] = byte(fv.Elem(1).(*reflect.UintValue).Get())
-				msg[off+4] = byte(fv.Elem(2).(*reflect.UintValue).Get() >> 8)
-				msg[off+5] = byte(fv.Elem(2).(*reflect.UintValue).Get())
-				off += 6
-			}
 		case *reflect.SliceValue:
 			switch f.Tag {
 			default:
@@ -335,6 +319,18 @@ func packStructValue(val *reflect.StructValue, msg []byte, off int) (off1 int, o
 				msg[off+2] = byte(i >> 8)
 				msg[off+3] = byte(i)
 				off += 4
+			case reflect.Uint64:
+				// Only used in TSIG, where it stops as 48 bits, discard the upper 16
+				if off+6 > len(msg) {
+					return len(msg), false
+				}
+				msg[off] = byte(i >> 40)
+				msg[off+1] = byte(i >> 32)
+				msg[off+2] = byte(i >> 24)
+				msg[off+3] = byte(i >> 16)
+				msg[off+4] = byte(i >> 8)
+				msg[off+5] = byte(i)
+				off += 6
 			}
 		case *reflect.StringValue:
 			// There are multiple string encodings.
@@ -398,14 +394,6 @@ func unpackStructValue(val *reflect.StructValue, msg []byte, off int) (off1 int,
 		BadType:
 			fmt.Fprintf(os.Stderr, "dns: unknown packing type %v", f.Type)
 			return len(msg), false
-		case *reflect.ArrayValue:
-			switch f.Tag {
-			default:
-				fmt.Fprintf(os.Stderr, "dns: unknown IP tag %v", f.Tag)
-				return len(msg), false
-			case "TSIG":
-                                println("TODO")
-			}
 		case *reflect.SliceValue:
 			switch f.Tag {
 			default:
@@ -469,6 +457,16 @@ func unpackStructValue(val *reflect.StructValue, msg []byte, off int) (off1 int,
 				i := uint32(msg[off])<<24 | uint32(msg[off+1])<<16 | uint32(msg[off+2])<<8 | uint32(msg[off+3])
 				fv.Set(uint64(i))
 				off += 4
+			case reflect.Uint64:
+				// This is *only* used in TSIG where the last 48 bits are occupied
+				// So for now, assume a uint48 (6 bytes)
+				if off+6 > len(msg) {
+					return len(msg), false
+				}
+				i := uint64(msg[off])<<40 | uint64(msg[off+1])<<32 | uint64(msg[off+2])<<24 | uint64(msg[off+3])<<16 |
+					uint64(msg[off+4])<<8 | uint64(msg[off+4])
+				fv.Set(uint64(i))
+				off += 6
 			}
 		case *reflect.StringValue:
 			var s string
diff --git a/tsig.go b/tsig.go
index bbdd7d7c..bd8f0d8d 100644
--- a/tsig.go
+++ b/tsig.go
@@ -17,12 +17,12 @@ const (
 
 type RR_TSIG struct {
 	Hdr        RR_Header
-	Algorithm  string    "domain-name"
-	TimeSigned [3]uint16 "TSIG"
+	Algorithm  string   "domain-name"
+	TimeSigned uint64
 	Fudge      uint16
 	MACSize    uint16
 	MAC        string
-        OrigId     uint16    // msg id
+	OrigId     uint16 // msg id
 	Error      uint16
 	OtherLen   uint16
 	OtherData  string
@@ -33,12 +33,12 @@ func (rr *RR_TSIG) Header() *RR_Header {
 }
 
 func (rr *RR_TSIG) String() string {
-        // It has no presentation format
+	// It has no presentation format
 	return rr.Hdr.String() +
-                " " + rr.Algorithm +
+		" " + rr.Algorithm +
 		" " + "<timesigned>" +
 		" " + strconv.Itoa(int(rr.Fudge)) +
-                " " + "<MAC>" +
+		" " + "<MAC>" +
 		" " + strconv.Itoa(int(rr.OrigId)) +
 		" " + strconv.Itoa(int(rr.Error)) +
 		" " + rr.OtherData
@@ -53,8 +53,8 @@ type tsig_generation_fmt struct {
 	Class uint16
 	Ttl   uint32
 	// Rdata of the TSIG
-	Algorithm  string    "domain-name"
-	TimeSigned [3]uint16 "TSIG"
+	Algorithm  string   "domain-name"
+	TimeSigned uint64
 	Fudge      uint16
 	// MACSize, MAC and OrigId excluded
 	Error     uint16
@@ -103,5 +103,8 @@ func (rr *RR_TSIG) Generate(msg *Msg, secret string) bool {
 // the TSIG record still attached (as the last rr in the Additional
 // section)
 func (rr *RR_TSIG) Verify(msg *Msg, secret string) bool {
+	// copy the mesg, strip (and check) the tsig rr
+	// perform the opposite of Generate() and then 
+	// verify the mac
 	return false
 }
diff --git a/types.go b/types.go
index 3b055706..1777f94f 100644
--- a/types.go
+++ b/types.go
@@ -535,6 +535,13 @@ func timeToDate(t uint32) string {
 	return ti.Format("20060102030405")
 }
 
+// Translate the TSIG time signed into a date. There is no
+// need for RFC1982 calculations as this date is 48 bits
+func tsigTimeToDate(t uint64) string {
+	// only use the lower 48 bits
+	return "TODO"
+}
+
 // Map of constructors for each RR wire type.
 var rr_mk = map[int]func() RR{
 	TypeCNAME:      func() RR { return new(RR_CNAME) },