Make tsigGenerateProvider public

Make it public as TsigGenerateWithProvider and update the docs a little.

Signed-off-by: Miek Gieben <miek@miek.nl>

client.go

@@ -358,7 +358,7 @@ func (co *Conn) WriteMsg(m *Msg) (err error) {
 	var out []byte
 	if t := m.IsTsig(); t != nil {
 		// Set tsigRequestMAC for the next read, although only used in zone transfers.
-		out, co.tsigRequestMAC, err = tsigGenerateProvider(m, co.tsigProvider(), co.tsigRequestMAC, false)
+		out, co.tsigRequestMAC, err = TsigGenerateWithProvider(m, co.tsigProvider(), co.tsigRequestMAC, false)
 	} else {
 		out, err = m.Pack()
 	}

server.go

@@ -728,7 +728,7 @@ func (w *response) WriteMsg(m *Msg) (err error) {
 	var data []byte
 	if w.tsigProvider != nil { // if no provider, dont check for the tsig (which is a longer check)
 		if t := m.IsTsig(); t != nil {
-			data, w.tsigRequestMAC, err = tsigGenerateProvider(m, w.tsigProvider, w.tsigRequestMAC, w.tsigTimersOnly)
+			data, w.tsigRequestMAC, err = TsigGenerateWithProvider(m, w.tsigProvider, w.tsigRequestMAC, w.tsigTimersOnly)
 			if err != nil {
 				return err
 			}

tsig.go

@@ -158,18 +158,17 @@ type timerWireFmt struct {
 }
 
 // TsigGenerate fills out the TSIG record attached to the message.
-// The message should contain
-// a "stub" TSIG RR with the algorithm, key name (owner name of the RR),
-// time fudge (defaults to 300 seconds) and the current time
-// The TSIG MAC is saved in that Tsig RR.
-// When TsigGenerate is called for the first time requestMAC is set to the empty string and
-// timersOnly is false.
-// If something goes wrong an error is returned, otherwise it is nil.
+// The message should contain a "stub" TSIG RR with the algorithm, key name
+// (owner name of the RR), time fudge (defaults to 300 seconds) and the current
+// time The TSIG MAC is saved in that Tsig RR. When TsigGenerate is called for
+// the first time requestMAC should be set to the empty string and timersOnly to
+// false.
 func TsigGenerate(m *Msg, secret, requestMAC string, timersOnly bool) ([]byte, string, error) {
-	return tsigGenerateProvider(m, tsigHMACProvider(secret), requestMAC, timersOnly)
+	return TsigGenerateWithProvider(m, tsigHMACProvider(secret), requestMAC, timersOnly)
 }
 
-func tsigGenerateProvider(m *Msg, provider TsigProvider, requestMAC string, timersOnly bool) ([]byte, string, error) {
+// TsigGenerateWithProvider is similar to TsigGenerate, but allows for a custom TsigProvider.
+func TsigGenerateWithProvider(m *Msg, provider TsigProvider, requestMAC string, timersOnly bool) ([]byte, string, error) {
 	if m.IsTsig() == nil {
 		panic("dns: TSIG not last RR in additional")
 	}

xfr.go

@@ -247,7 +247,7 @@ func (t *Transfer) ReadMsg() (*Msg, error) {
 func (t *Transfer) WriteMsg(m *Msg) (err error) {
 	var out []byte
 	if ts, tp := m.IsTsig(), t.tsigProvider(); ts != nil && tp != nil {
-		out, t.tsigRequestMAC, err = tsigGenerateProvider(m, tp, t.tsigRequestMAC, t.tsigTimersOnly)
+		out, t.tsigRequestMAC, err = TsigGenerateWithProvider(m, tp, t.tsigRequestMAC, t.tsigTimersOnly)
 	} else {
 		out, err = m.Pack()
 	}