Is forgiving of spelling mistakes beyond the 1st 4 characters.

This commit is contained in:
Oran Juice 2014-09-30 23:30:27 +05:30
parent cf70cc7787
commit 4cbf8d4243
No known key found for this signature in database
GPG key ID: 71C5AF46CCB28124
2 changed files with 72 additions and 32 deletions

View file

@ -64,6 +64,7 @@ namespace
const std::string LANGUAGES_DIRECTORY = "languages";
const std::string OLD_WORD_FILE = "old-word-list";
const int unique_prefix_length = 4;
/*!
* \brief Tells if the module hasn't been initialized with a word list file.
* \return true if the module hasn't been initialized with a word list file false otherwise.
@ -77,8 +78,9 @@ namespace
* \brief Create word list map and array data structres for use during inter-conversion between
* words and secret key.
* \param word_file Path to the word list file from pwd.
* \param has_checksum True if checksum was supplied false if not.
*/
void create_data_structures(const std::string &word_file)
void create_data_structures(const std::string &word_file, bool has_checksum)
{
words_array.clear();
words_map.clear();
@ -93,7 +95,15 @@ namespace
while (input_stream >> word)
{
words_array.push_back(word);
if (has_checksum)
{
// Only if checksum was passed should we stick to just 4 char checks to be lenient about typos.
words_map[word.substr(0, unique_prefix_length)] = num_words;
}
else
{
words_map[word] = num_words;
}
num_words++;
}
input_stream.close();
@ -102,29 +112,46 @@ namespace
/*!
* \brief Tells if all the words passed in wlist was present in current word list file.
* \param wlist List of words to match.
* \param has_checksum If word list passed checksum test, we need to only do a 4 char check.
* \return true if all the words were present false if not.
*/
bool word_list_file_match(const std::vector<std::string> &wlist)
bool word_list_file_match(const std::vector<std::string> &wlist, bool has_checksum)
{
for (std::vector<std::string>::const_iterator it = wlist.begin(); it != wlist.end(); it++)
{
if (has_checksum)
{
if (words_map.count(it->substr(0, unique_prefix_length)) == 0)
{
return false;
}
}
else
{
if (words_map.count(*it) == 0)
{
return false;
}
}
}
return true;
}
/*!
* \brief Creates a checksum index in the word list array on the list of words.
* \param words Space separated list of words
* \param word_list Vector of words
* \return Checksum index
*/
uint32_t create_checksum_index(const std::string &words)
uint32_t create_checksum_index(const std::vector<std::string> &word_list)
{
std::string four_char_words = "";
for (std::vector<std::string>::const_iterator it = word_list.begin(); it != word_list.end(); it++)
{
four_char_words += it->substr(0, unique_prefix_length);
}
boost::crc_32_type result;
result.process_bytes(words.data(), words.length());
result.process_bytes(four_char_words.data(), four_char_words.length());
return result.checksum() % seed_length;
}
}
@ -144,21 +171,22 @@ namespace crypto
namespace ElectrumWords
{
/*!
* \brief Called to initialize it work with a word list file.
* \brief Called to initialize it to work with a word list file.
* \param language Language of the word list file.
* \param has_checksum True if the checksum was passed false if not.
* \param old_word_list true it is to use the old style word list file false if not.
*/
void init(const std::string &language, bool old_word_list)
void init(const std::string &language, bool has_checksum, bool old_word_list)
{
if (old_word_list)
{
// Use the old word list file if told to.
create_data_structures(WORD_LISTS_DIRECTORY + '/' + OLD_WORD_FILE);
create_data_structures(WORD_LISTS_DIRECTORY + '/' + OLD_WORD_FILE, has_checksum);
is_old_style_word_list = true;
}
else
{
create_data_structures(WORD_LISTS_DIRECTORY + '/' + LANGUAGES_DIRECTORY + '/' + language);
create_data_structures(WORD_LISTS_DIRECTORY + '/' + LANGUAGES_DIRECTORY + '/' + language, has_checksum);
is_old_style_word_list = false;
}
if (num_words == 0)
@ -181,15 +209,17 @@ namespace crypto
boost::split(wlist, words, boost::is_any_of(" "));
// If it is seed with a checksum.
if (wlist.size() == seed_length + 1)
bool has_checksum = (wlist.size() == seed_length + 1);
if (has_checksum)
{
// The last word is the checksum.
std::string last_word = wlist.back();
wlist.pop_back();
std::string checksum = wlist[create_checksum_index(boost::algorithm::join(wlist, " "))];
std::string checksum = wlist[create_checksum_index(wlist)];
if (checksum != last_word)
if (checksum.substr(0, unique_prefix_length) != last_word.substr(0, unique_prefix_length))
{
// Checksum fail
return false;
@ -202,8 +232,8 @@ namespace crypto
std::vector<std::string>::iterator it;
for (it = languages.begin(); it != languages.end(); it++)
{
init(*it);
if (word_list_file_match(wlist))
init(*it, has_checksum);
if (word_list_file_match(wlist, has_checksum))
{
break;
}
@ -211,8 +241,8 @@ namespace crypto
// If no such file was found, see if the old style word list file has them all.
if (it == languages.end())
{
init("", true);
if (!word_list_file_match(wlist))
init("", has_checksum, true);
if (!word_list_file_match(wlist, has_checksum))
{
return false;
}
@ -227,9 +257,18 @@ namespace crypto
uint32_t val;
uint32_t w1, w2, w3;
if (has_checksum)
{
w1 = words_map.at(wlist[i*3].substr(0, unique_prefix_length));
w2 = words_map.at(wlist[i*3 + 1].substr(0, unique_prefix_length));
w3 = words_map.at(wlist[i*3 + 2].substr(0, unique_prefix_length));
}
else
{
w1 = words_map.at(wlist[i*3]);
w2 = words_map.at(wlist[i*3 + 1]);
w3 = words_map.at(wlist[i*3 + 2]);
}
val = w1 + n * (((n - w1) + w2) % n) + n * n * (((n - w2) + w3) % n);
@ -293,7 +332,7 @@ namespace crypto
}
words.pop_back();
words += (' ' + words_store[create_checksum_index(words)]);
words += (' ' + words_store[create_checksum_index(words_store)]);
return false;
}

View file

@ -58,9 +58,10 @@ namespace crypto
/*!
* \brief Called to initialize it to work with a word list file.
* \param language Language of the word list file.
* \param old_word_list Whether it is to use the old style word list file.
* \param has_checksum True if the checksum was passed false if not.
* \param old_word_list true it is to use the old style word list file false if not.
*/
void init(const std::string &language, bool old_word_list=false);
void init(const std::string &language, bool has_checksum=true, bool old_word_list=false);
/*!
* \brief Converts seed words to bytes (secret key).