default to higher entropy output

cmd/genpw/cli.go

@@ -17,7 +17,6 @@ type Passphrase struct {
 }
 
 func main() {
-	g := cryptipass.NewInstance()
 	f_pattern := flag.String("p", "W.w.w",
 		`pattern used to generate passphrase e.g. try:
 	-p WWW20dd
@@ -28,7 +27,11 @@ func main() {
 	- 's' symbol, 'd' digit.
 	`)
 	passwords := flag.Uint64("n", 6, "number of passwords to generate")
+	depth := flag.Uint64("d", 3, "markov chain depth, higher values lead to more plausible words but lower entropy")
 	flag.Parse()
+
+	g := cryptipass.NewCustomInstance(cryptipass.WordListEFF(), int(*depth))
+
 	pattern := *f_pattern
 
 	w := tabwriter.NewWriter(os.Stdout, 1, 1, 4, ' ', 0)

cryptipass.go

@@ -42,6 +42,9 @@ import (
 // If the random seed cannot be read from the crypto/rand source, the function
 // will log a fatal error and terminate the application.
 func NewCustomInstance(tokens []string, chain_depth int) *Generator {
+	if chain_depth < 1 {
+		panic("chain depths cannot be below 1")
+	}
 	rng := new_chacha8_rng()
 	g := new(Generator)
 	g.Rng = rng
@@ -83,8 +86,8 @@ func NewInstance() *Generator {
 var global_jump_table Generator
 
 func init() {
-	global_jump_table.depth = 3
-	global_jump_table.jump_table = distill(WordListEFF(), 3)
+	global_jump_table.depth = 2
+	global_jump_table.jump_table = distill(WordListEFF(), 2)
 }
 
 // GenPassphrase generates a passphrase composed of a specified number of words.