Merge pull request #18 from tcharding/word-counts

Allow word count multiples of 3 instead of 6

src/lib.rs

@@ -250,7 +250,7 @@ impl Mnemonic {
  where
  R: rand_core::RngCore + rand_core::CryptoRng,
  {
- if word_count < MIN_NB_WORDS || word_count % 6 != 0 || word_count > MAX_NB_WORDS {
+ if is_invalid_word_count(word_count) {
  return Err(Error::BadWordCount(word_count));
  }
 
@@ -377,7 +377,7 @@ impl Mnemonic {
  /// Parse a mnemonic in normalized UTF8 in the given language.
  pub fn parse_in_normalized(language: Language, s: &str) -> Result<Mnemonic, Error> {
  let nb_words = s.split_whitespace().count();
- if nb_words < MIN_NB_WORDS || nb_words % 6 != 0 || nb_words > MAX_NB_WORDS {
+ if is_invalid_word_count(nb_words) {
  return Err(Error::BadWordCount(nb_words));
  }
 
@@ -558,6 +558,10 @@ impl str::FromStr for Mnemonic {
  }
 }
 
+fn is_invalid_word_count(word_count: usize) -> bool {
+ word_count < MIN_NB_WORDS || word_count % 3 != 0 || word_count > MAX_NB_WORDS
+}
+
 #[cfg(test)]
 mod tests {
  use super::*;
@@ -605,6 +609,14 @@ mod tests {
  let _ = Mnemonic::generate_in_with(&mut rand::thread_rng(), Language::English, 24).unwrap();
  }
 
+ #[cfg(feature = "rand")]
+ #[test]
+ fn test_generate_word_counts() {
+ for word_count in [12, 15, 18, 21, 24].iter() {
+ let _ = Mnemonic::generate(*word_count).unwrap();
+ }
+ }
+
  #[test]
  fn test_vectors_english() {
  // These vectors are tuples of