// Copyright (c) 2014-2015, The Monero Project
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/*!
* \file electrum-words.cpp
*
* \brief Mnemonic seed generation and wallet restoration from them.
*
* This file and its header file are for translating Electrum-style word lists
* into their equivalent byte representations for cross-compatibility with
* that method of "backing up" one's wallet keys.
*/
#include <string>
#include <cassert>
#include <map>
#include <cstdint>
#include <vector>
#include <unordered_map>
#include <boost/algorithm/string.hpp>
#include "crypto/crypto.h" // for declaration of crypto::secret_key
#include <fstream>
#include "mnemonics/electrum-words.h"
#include <stdexcept>
#include <boost/filesystem.hpp>
#include <boost/crc.hpp>
#include <boost/algorithm/string/join.hpp>
#include "english.h"
#include "spanish.h"
#include "portuguese.h"
#include "japanese.h"
#include "old_english.h"
#include "language_base.h"
#include "singleton.h"
namespace
{
/*!
* \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 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.
*/
bool find_seed_language(const std::vector<std::string> &seed,
bool has_checksum, std::vector<uint32_t> &matched_indices, Language::Base **language)
{
// If there's a new language added, add an instance of it here.
std::vector<Language::Base*> language_instances({
Language::Singleton<Language::English>::instance(),
Language::Singleton<Language::Spanish>::instance(),
Language::Singleton<Language::Portuguese>::instance(),
Language::Singleton<Language::Japanese>::instance(),
Language::Singleton<Language::OldEnglish>::instance()
});
// Iterate through all the languages and find a match
for (std::vector<Language::Base*>::iterator it1 = language_instances.begin();
it1 != language_instances.end(); it1++)
{
const std::unordered_map<std::string, uint32_t> &word_map = (*it1)->get_word_map();
const std::unordered_map<std::string, uint32_t> &trimmed_word_map = (*it1)->get_trimmed_word_map();
// To iterate through seed words
std::vector<std::string>::const_iterator it2;
bool full_match = true;
std::string trimmed_word;
// Iterate through all the words and see if they're all present
for (it2 = seed.begin(); it2 != seed.end(); it2++)
{
if (has_checksum)
{
trimmed_word = Language::utf8prefix(*it2, (*it1)->get_unique_prefix_length());
// Use the trimmed words and map
if (trimmed_word_map.count(trimmed_word) == 0)
{
full_match = false;
break;
}
matched_indices.push_back(trimmed_word_map.at(trimmed_word));
}
else
{
if (word_map.count(*it2) == 0)
{
full_match = false;
break;
}
matched_indices.push_back(word_map.at(*it2));
}
}
if (full_match)
{
*language = *it1;
return true;
}
// Some didn't match. Clear the index array.
matched_indices.clear();
}
return false;
}
/*!
* \brief Creates a checksum index in the word list array on the list of words.
* \param word_list Vector of words
* \param unique_prefix_length the prefix length of each word to use for checksum
* \return Checksum index
*/
uint32_t create_checksum_index(const std::vector<std::string> &word_list,
uint32_t unique_prefix_length)
{
std::string trimmed_words = "";
for (std::vector<std::string>::const_iterator it = word_list.begin(); it != word_list.end(); it++)
{
if (it->length() > unique_prefix_length)
{
trimmed_words += Language::utf8prefix(*it, unique_prefix_length);
}
else
{
trimmed_words += *it;
}
}
boost::crc_32_type result;
result.process_bytes(trimmed_words.data(), trimmed_words.length());
return result.checksum() % crypto::ElectrumWords::seed_length;
}
/*!
* \brief Does the checksum test on the seed passed.
* \param seed Vector of seed words
* \param unique_prefix_length the prefix length of each word to use for checksum
* \return True if the test passed false if not.
*/
bool checksum_test(std::vector<std::string> seed, uint32_t unique_prefix_length)
{
// The last word is the checksum.
std::string last_word = seed.back();
seed.pop_back();
std::string checksum = seed[create_checksum_index(seed, unique_prefix_length)];
std::string trimmed_checksum = checksum.length() > unique_prefix_length ? Language::utf8prefix(checksum, unique_prefix_length) :
checksum;
std::string trimmed_last_word = last_word.length() > unique_prefix_length ? Language::utf8prefix(last_word, unique_prefix_length) :
last_word;
return trimmed_checksum == trimmed_last_word;
}
}
/*!
* \namespace crypto
*
* \brief crypto namespace.
*/
namespace crypto
{
/*!
* \namespace crypto::ElectrumWords
*
* \brief Mnemonic seed word generation and wallet restoration helper functions.
*/
namespace ElectrumWords
{
/*!
* \brief Converts seed words to bytes (secret key).
* \param words String containing the words separated by spaces.
* \param dst To put the secret key restored from the words.
* \param language_name Language of the seed as found gets written here.
* \return false if not a multiple of 3 words, or if word is not in the words list
*/
bool words_to_bytes(std::string words, crypto::secret_key& dst,
std::string &language_name)
{
std::vector<std::string> seed;
boost::algorithm::trim(words);
boost::split(seed, words, boost::is_any_of(" "));
// error on non-compliant word list
if (seed.size() != seed_length/2 && seed.size() != seed_length &&
seed.size() != seed_length + 1)
{
return false;
}
// If it is seed with a checksum.
bool has_checksum = seed.size() == (seed_length + 1);
std::vector<uint32_t> matched_indices;
Language::Base *language;
if (!find_seed_language(seed, has_checksum, matched_indices, &language))
{
return false;
}
language_name = language->get_language_name();
uint32_t word_list_length = language->get_word_list().size();
if (has_checksum)
{
if (!checksum_test(seed, language->get_unique_prefix_length()))
{
// Checksum fail
return false;
}
seed.pop_back();
}
for (unsigned int i=0; i < seed.size() / 3; i++)
{
uint32_t val;
uint32_t w1, w2, w3;
w1 = matched_indices[i*3];
w2 = matched_indices[i*3 + 1];
w3 = matched_indices[i*3 + 2];
val = w1 + word_list_length * (((word_list_length - w1) + w2) % word_list_length) +
word_list_length * word_list_length * (((word_list_length - w2) + w3) % word_list_length);
if (!(val % word_list_length == w1)) return false;
memcpy(dst.data + i * 4, &val, 4); // copy 4 bytes to position
}
std::string wlist_copy = words;
if (seed.size() == seed_length/2)
{
memcpy(dst.data+16, dst.data, 16); // if electrum 12-word seed, duplicate
wlist_copy += ' ';
wlist_copy += words;
}
return true;
}
/*!
* \brief Converts bytes (secret key) to seed words.
* \param src Secret key
* \param words Space delimited concatenated words get written here.
* \param language_name Seed language name
* \return true if successful false if not. Unsuccessful if wrong key size.
*/
bool bytes_to_words(const crypto::secret_key& src, std::string& words,
const std::string &language_name)
{
if (sizeof(src.data) % 4 != 0 || sizeof(src.data) == 0) return false;
Language::Base *language;
if (language_name == "English")
{
language = Language::Singleton<Language::English>::instance();
}
else if (language_name == "Spanish")
{
language = Language::Singleton<Language::Spanish>::instance();
}
else if (language_name == "Portuguese")
{
language = Language::Singleton<Language::Portuguese>::instance();
}
else if (language_name == "Japanese")
{
language = Language::Singleton<Language::Japanese>::instance();
}
else
{
return false;
}
const std::vector<std::string> &word_list = language->get_word_list();
// To store the words for random access to add the checksum word later.
std::vector<std::string> words_store;
uint32_t word_list_length = word_list.size();
// 8 bytes -> 3 words. 8 digits base 16 -> 3 digits base 1626
for (unsigned int i=0; i < sizeof(src.data)/4; i++, words += ' ')
{
uint32_t w1, w2, w3;
uint32_t val;
memcpy(&val, (src.data) + (i * 4), 4);
w1 = val % word_list_length;
w2 = ((val / word_list_length) + w1) % word_list_length;
w3 = (((val / word_list_length) / word_list_length) + w2) % word_list_length;
words += word_list[w1];
words += ' ';
words += word_list[w2];
words += ' ';
words += word_list[w3];
words_store.push_back(word_list[w1]);
words_store.push_back(word_list[w2]);
words_store.push_back(word_list[w3]);
}
words.pop_back();
words += (' ' + words_store[create_checksum_index(words_store, language->get_unique_prefix_length())]);
return true;
}
/*!
* \brief Gets a list of seed languages that are supported.
* \param languages The vector is set to the list of languages.
*/
void get_language_list(std::vector<std::string> &languages)
{
std::vector<Language::Base*> language_instances({
Language::Singleton<Language::English>::instance(),
Language::Singleton<Language::Spanish>::instance(),
Language::Singleton<Language::Portuguese>::instance(),
Language::Singleton<Language::Japanese>::instance()
});
for (std::vector<Language::Base*>::iterator it = language_instances.begin();
it != language_instances.end(); it++)
{
languages.push_back((*it)->get_language_name());
}
}
/*!
* \brief Tells if the seed passed is an old style seed or not.
* \param seed The seed to check (a space delimited concatenated word list)
* \return true if the seed passed is a old style seed false if not.
*/
bool get_is_old_style_seed(const std::string &seed)
{
std::vector<std::string> word_list;
boost::split(word_list, seed, boost::is_any_of(" "));
return word_list.size() != (seed_length + 1);
}
}
}