diff options
| -rw-r--r-- | src/mnemonics/electrum-words.cpp | 27 | ||||
| -rw-r--r-- | tests/unit_tests/mnemonics.cpp | 19 |
2 files changed, 45 insertions, 1 deletions
diff --git a/src/mnemonics/electrum-words.cpp b/src/mnemonics/electrum-words.cpp index 33d36d2d0..f0e254ba4 100644 --- a/src/mnemonics/electrum-words.cpp +++ b/src/mnemonics/electrum-words.cpp @@ -64,12 +64,15 @@ namespace { + uint32_t create_checksum_index(const std::vector<std::string> &word_list, + uint32_t unique_prefix_length); + bool checksum_test(std::vector<std::string> seed, uint32_t unique_prefix_length); /*! * \brief Finds the word list that contains the seed words and puts the indices * where matches occured in matched_indices. * \param seed List of words to match. - * \param has_checksum If word list passed checksum test, we need to only do a prefix check. + * \param has_checksum The seed has a checksum word (maybe not checked). * \param matched_indices The indices where the seed words were found are added to this. * \param language Language instance pointer to write to after it is found. * \return true if all the words were present in some language false if not. @@ -88,6 +91,7 @@ namespace Language::Singleton<Language::Russian>::instance(), Language::Singleton<Language::OldEnglish>::instance() }); + Language::Base *fallback = NULL; // Iterate through all the languages and find a match for (std::vector<Language::Base*>::iterator it1 = language_instances.begin(); @@ -126,12 +130,33 @@ namespace } if (full_match) { + // if we were using prefix only, and we have a checksum, check it now + // to avoid false positives due to prefix set being too common + if (has_checksum) + if (!checksum_test(seed, (*it1)->get_unique_prefix_length())) + { + fallback = *it1; + full_match = false; + } + } + if (full_match) + { *language = *it1; return true; } // Some didn't match. Clear the index array. matched_indices.clear(); } + + // if we get there, we've not found a good match, but we might have a fallback, + // if we detected a match which did not fit the checksum, which might be a badly + // typed/transcribed seed in the right language + if (fallback) + { + *language = fallback; + return true; + } + return false; } diff --git a/tests/unit_tests/mnemonics.cpp b/tests/unit_tests/mnemonics.cpp index 3dc5db7d4..9c497ef29 100644 --- a/tests/unit_tests/mnemonics.cpp +++ b/tests/unit_tests/mnemonics.cpp @@ -148,3 +148,22 @@ TEST(mnemonics, all_languages) test_language(*(*it)); } } + +TEST(mnemonics, language_detection_with_bad_checksum) +{ + crypto::secret_key key; + std::string language_name; + bool res; + + // This Portuguese (4-prefix) seed has all its words with 3-prefix that's also present in English + const std::string base_seed = "cinzento luxuriante leonardo gnostico digressao cupula fifa broxar iniquo louvor ovario dorsal ideologo besuntar decurso rosto susto lemure unheiro pagodeiro nitroglicerina eclusa mazurca bigorna"; + const std::string real_checksum = "gnostico"; + + res = crypto::ElectrumWords::words_to_bytes(base_seed, key, language_name); + ASSERT_EQ(true, res); + ASSERT_STREQ(language_name.c_str(), "Portuguese"); + + res = crypto::ElectrumWords::words_to_bytes(base_seed + " " + real_checksum, key, language_name); + ASSERT_EQ(true, res); + ASSERT_STREQ(language_name.c_str(), "Portuguese"); +} |