fuzz/brontide: random+static decrypt harnesses

fuzz/brontide/random_init_decrypt.go

@@ -0,0 +1,27 @@
+// +build gofuzz
+
+package brontidefuzz
+
+import (
+	"bytes"
+)
+
+// Fuzz_random_init_decrypt is a go-fuzz harness that decrypts arbitrary data
+// with the initiator.
+func Fuzz_random_init_decrypt(data []byte) int {
+	// This will return brontide machines with random keys.
+	initiator, responder := getBrontideMachines()
+
+	// Complete the brontide handshake.
+	completeHandshake(initiator, responder)
+
+	// Create a reader with the byte array.
+	r := bytes.NewReader(data)
+
+	// Decrypt the encrypted message using ReadMessage w/ initiator machine.
+	if _, err := initiator.ReadMessage(r); err == nil {
+		nilAndPanic(initiator, responder, nil)
+	}
+
+	return 1
+}