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mnemonics: compare canonical words (lowercase)

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moneromooo-monero committed Jan 11, 2019
1 parent 42abea7 commit 11227e0ba24c9c2c38ab5691e3b5950358f84175
Showing with 115 additions and 24 deletions.
  1. +23 −20 src/mnemonics/electrum-words.cpp
  2. +92 −4 src/mnemonics/language_base.h
@@ -76,8 +76,8 @@ namespace crypto
namespace
{
uint32_t create_checksum_index(const std::vector<epee::wipeable_string> &word_list,
uint32_t unique_prefix_length);
bool checksum_test(std::vector<epee::wipeable_string> seed, uint32_t unique_prefix_length);
const Language::Base *language);
bool checksum_test(std::vector<epee::wipeable_string> seed, const Language::Base *language);

/*!
* \brief Finds the word list that contains the seed words and puts the indices
@@ -116,8 +116,8 @@ namespace
for (std::vector<Language::Base*>::iterator it1 = language_instances.begin();
it1 != language_instances.end(); it1++)
{
const std::unordered_map<epee::wipeable_string, uint32_t> &word_map = (*it1)->get_word_map();
const std::unordered_map<epee::wipeable_string, uint32_t> &trimmed_word_map = (*it1)->get_trimmed_word_map();
const std::unordered_map<epee::wipeable_string, uint32_t, Language::WordHash, Language::WordEqual> &word_map = (*it1)->get_word_map();
const std::unordered_map<epee::wipeable_string, uint32_t, Language::WordHash, Language::WordEqual> &trimmed_word_map = (*it1)->get_trimmed_word_map();
// To iterate through seed words
bool full_match = true;

@@ -151,7 +151,7 @@ namespace
// 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()))
if (!checksum_test(seed, *it1))
{
fallback = *it1;
full_match = false;
@@ -190,20 +190,20 @@ namespace
* \return Checksum index
*/
uint32_t create_checksum_index(const std::vector<epee::wipeable_string> &word_list,
uint32_t unique_prefix_length)
const Language::Base *language)
{
epee::wipeable_string trimmed_words = "";
epee::wipeable_string trimmed_words = "", word;

const auto &word_map = language->get_word_map();
const auto &trimmed_word_map = language->get_trimmed_word_map();
const uint32_t unique_prefix_length = language->get_unique_prefix_length();
for (std::vector<epee::wipeable_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;
}
word = Language::utf8prefix(*it, unique_prefix_length);
auto it2 = trimmed_word_map.find(word);
if (it2 == trimmed_word_map.end())
throw std::runtime_error("Word \"" + std::string(word.data(), word.size()) + "\" not found in trimmed word map in " + language->get_english_language_name());
trimmed_words += it2->first;
}
boost::crc_32_type result;
result.process_bytes(trimmed_words.data(), trimmed_words.length());
@@ -216,21 +216,24 @@ namespace
* \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<epee::wipeable_string> seed, uint32_t unique_prefix_length)
bool checksum_test(std::vector<epee::wipeable_string> seed, const Language::Base *language)
{
if (seed.empty())
return false;
// The last word is the checksum.
epee::wipeable_string last_word = seed.back();
seed.pop_back();

epee::wipeable_string checksum = seed[create_checksum_index(seed, unique_prefix_length)];
const uint32_t unique_prefix_length = language->get_unique_prefix_length();

auto idx = create_checksum_index(seed, language);
epee::wipeable_string checksum = seed[idx];

epee::wipeable_string trimmed_checksum = checksum.length() > unique_prefix_length ? Language::utf8prefix(checksum, unique_prefix_length) :
checksum;
epee::wipeable_string trimmed_last_word = last_word.length() > unique_prefix_length ? Language::utf8prefix(last_word, unique_prefix_length) :
last_word;
bool ret = trimmed_checksum == trimmed_last_word;
bool ret = Language::WordEqual()(trimmed_checksum, trimmed_last_word);
MINFO("Checksum is " << (ret ? "valid" : "invalid"));
return ret;
}
@@ -301,7 +304,7 @@ namespace crypto

if (has_checksum)
{
if (!checksum_test(seed, language->get_unique_prefix_length()))
if (!checksum_test(seed, language))
{
// Checksum fail
MERROR("Invalid seed: invalid checksum");
@@ -424,7 +427,7 @@ namespace crypto
memwipe(w, sizeof(w));
}

words += words_store[create_checksum_index(words_store, language->get_unique_prefix_length())];
words += words_store[create_checksum_index(words_store, language)];
return true;
}

@@ -38,7 +38,9 @@
#include <vector>
#include <unordered_map>
#include <string>
#include <boost/algorithm/string.hpp>
#include "misc_log_ex.h"
#include "fnv1.h"

/*!
* \namespace Language
@@ -71,6 +73,92 @@ namespace Language
return prefix;
}

template<typename T>
inline T utf8canonical(const T &s)
{
T sc = "";
size_t avail = s.size();
const char *ptr = s.data();
wint_t cp = 0;
int bytes = 1;
char wbuf[8], *wptr;
while (avail--)
{
if ((*ptr & 0x80) == 0)
{
cp = *ptr++;
bytes = 1;
}
else if ((*ptr & 0xe0) == 0xc0)
{
if (avail < 1)
throw std::runtime_error("Invalid UTF-8");
cp = (*ptr++ & 0x1f) << 6;
cp |= *ptr++ & 0x3f;
--avail;
bytes = 2;
}
else if ((*ptr & 0xf0) == 0xe0)
{
if (avail < 2)
throw std::runtime_error("Invalid UTF-8");
cp = (*ptr++ & 0xf) << 12;
cp |= (*ptr++ & 0x3f) << 6;
cp |= *ptr++ & 0x3f;
avail -= 2;
bytes = 3;
}
else if ((*ptr & 0xf8) == 0xf0)
{
if (avail < 3)
throw std::runtime_error("Invalid UTF-8");
cp = (*ptr++ & 0x7) << 18;
cp |= (*ptr++ & 0x3f) << 12;
cp |= (*ptr++ & 0x3f) << 6;
cp |= *ptr++ & 0x3f;
avail -= 3;
bytes = 4;
}
else
throw std::runtime_error("Invalid UTF-8");

cp = std::towlower(cp);
wptr = wbuf;
switch (bytes)
{
case 1: *wptr++ = cp; break;
case 2: *wptr++ = 0xc0 | (cp >> 6); *wptr++ = 0x80 | (cp & 0x3f); break;
case 3: *wptr++ = 0xe0 | (cp >> 12); *wptr++ = 0x80 | ((cp >> 6) & 0x3f); *wptr++ = 0x80 | (cp & 0x3f); break;
case 4: *wptr++ = 0xf0 | (cp >> 18); *wptr += 0x80 | ((cp >> 12) & 0x3f); *wptr++ = 0x80 | ((cp >> 6) & 0x3f); *wptr++ = 0x80 | (cp & 0x3f); break;
default: throw std::runtime_error("Invalid UTF-8");
}
*wptr = 0;
sc += T(wbuf, bytes);
cp = 0;
bytes = 1;
}
return sc;
}

struct WordHash
{
std::size_t operator()(const epee::wipeable_string &s) const
{
const epee::wipeable_string sc = utf8canonical(s);
return epee::fnv::FNV1a(sc.data(), sc.size());
}
};

struct WordEqual
{
bool operator()(const epee::wipeable_string &s0, const epee::wipeable_string &s1) const
{
const epee::wipeable_string s0c = utf8canonical(s0);
const epee::wipeable_string s1c = utf8canonical(s1);
return s0c == s1c;
}
};

/*!
* \class Base
* \brief A base language class which all languages have to inherit from for
@@ -87,8 +175,8 @@ namespace Language
NWORDS = 1626
};
std::vector<std::string> word_list; /*!< A pointer to the array of words */
std::unordered_map<epee::wipeable_string, uint32_t> word_map; /*!< hash table to find word's index */
std::unordered_map<epee::wipeable_string, uint32_t> trimmed_word_map; /*!< hash table to find word's trimmed index */
std::unordered_map<epee::wipeable_string, uint32_t, WordHash, WordEqual> word_map; /*!< hash table to find word's index */
std::unordered_map<epee::wipeable_string, uint32_t, WordHash, WordEqual> trimmed_word_map; /*!< hash table to find word's trimmed index */
std::string language_name; /*!< Name of language */
std::string english_language_name; /*!< Name of language */
uint32_t unique_prefix_length; /*!< Number of unique starting characters to trim the wordlist to when matching */
@@ -159,15 +247,15 @@ namespace Language
* \brief Returns a pointer to the word map.
* \return A pointer to the word map.
*/
const std::unordered_map<epee::wipeable_string, uint32_t>& get_word_map() const
const std::unordered_map<epee::wipeable_string, uint32_t, WordHash, WordEqual>& get_word_map() const
{
return word_map;
}
/*!
* \brief Returns a pointer to the trimmed word map.
* \return A pointer to the trimmed word map.
*/
const std::unordered_map<epee::wipeable_string, uint32_t>& get_trimmed_word_map() const
const std::unordered_map<epee::wipeable_string, uint32_t, WordHash, WordEqual>& get_trimmed_word_map() const
{
return trimmed_word_map;
}

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