Better document magic numbers

6 years ago · 0e61ab8ccc
parent 16e51a2c7a
commit 0e61ab8ccc
1 changed files with 4 additions and 1 deletions
--- a/libtextsecure/account_manager.js
+++ b/libtextsecure/account_manager.js
@ -523,7 +523,10 @@
      });
    },
    async generateMnemonic(language = 'english') {
-      const seed = window.Signal.Crypto.getRandomBytes(16);
+      // Note: 4 bytes are converted into 3 seed words, so length 12 seed words
+      // (13 - 1 checksum) are generated using 12 * 4 / 3 = 16 bytes.
+      const seedSize = 16;
+      const seed = window.Signal.Crypto.getRandomBytes(seedSize);
      const hex = StringView.arrayBufferToHex(seed);
      return mnemonic.mn_encode(hex, language);
    },