fix incorrect logic in rotateSequence

This was introduced in the previous few commits when adding support for multiple secrets in knockd.  The logic to push and pop entries from the knockSequences slice needed to be adjusted to cound for the number of secrets that are loaded by hypd.

.gitignore

@@ -2,4 +2,5 @@ hyp.secret
 *.exe
 hypd/hypd
 hyp/hyp
-hypd/hypdconfig.json
+hypd/hypdconfig.json
+hypd/secrets/

hypd/server/packet.go

@@ -175,7 +175,7 @@ func rotateSequence() {
 	for {
 		// Generate new knock sequences with time skew support
 		t := time.Now().Add(time.Second * -30)
-		for i := len(knockSequences); i < 3; i++ {
+		for i := len(knockSequences) / len(sharedSecrets); i < 3; i++ {
 			for _, secret := range sharedSecrets {
 				portSequence, err := otphyp.GeneratePorts(secret, t.Add((time.Second * 30 * time.Duration(i))))
 				if err != nil {
@@ -190,7 +190,7 @@ func rotateSequence() {
 		time.Sleep(time.Until(time.Now().Truncate(time.Second * 30).Add(time.Second * 30)))
 
 		// pop first value, next iteration pushes new value
-		knockSequences = knockSequences[1:]
+		knockSequences = knockSequences[len(sharedSecrets):]
 	}
 }