diff --git a/src/logging.cpp b/src/logging.cpp index 7ac3cc7594..1a65a8534c 100644 --- a/src/logging.cpp +++ b/src/logging.cpp @@ -261,10 +261,32 @@ std::string BCLog::Logger::LogTimestampStr(const std::string& str) return strStamped; } +namespace BCLog { + /** Belts and suspenders: make sure outgoing log messages don't contain + * potentially suspicious characters, such as terminal control codes. + * + * This escapes control characters except newline ('\n') in C syntax. + * It escapes instead of removes them to still allow for troubleshooting + * issues where they accidentally end up in strings. + */ + std::string LogEscapeMessage(const std::string& str) { + std::string ret; + for (char ch_in : str) { + uint8_t ch = (uint8_t)ch_in; + if ((ch >= 32 || ch == '\n') && ch != '\x7f') { + ret += ch_in; + } else { + ret += strprintf("\\x%02x", ch); + } + } + return ret; + } +} + void BCLog::Logger::LogPrintStr(const std::string& str) { StdLockGuard scoped_lock(m_cs); - std::string str_prefixed = str; + std::string str_prefixed = LogEscapeMessage(str); if (m_log_threadnames && m_started_new_line) { // 16 chars total, "dash-" is 5 of them and another 1 is a NUL terminator diff --git a/src/test/util_tests.cpp b/src/test/util_tests.cpp index 9362f662d4..4dbf4419aa 100644 --- a/src/test/util_tests.cpp +++ b/src/test/util_tests.cpp @@ -25,6 +25,11 @@ #include +/* defined in logging.cpp */ +namespace BCLog { + std::string LogEscapeMessage(const std::string& str); +} + BOOST_FIXTURE_TEST_SUITE(util_tests, BasicTestingSetup) BOOST_AUTO_TEST_CASE(util_criticalsection) @@ -1474,4 +1479,17 @@ BOOST_AUTO_TEST_CASE(test_spanparsing) BOOST_CHECK_EQUAL(SpanToStr(results[3]), ""); } +BOOST_AUTO_TEST_CASE(test_LogEscapeMessage) +{ + // ASCII and UTF-8 must pass through unaltered. + BOOST_CHECK_EQUAL(BCLog::LogEscapeMessage("Valid log message貓"), "Valid log message貓"); + // Newlines must pass through unaltered. + BOOST_CHECK_EQUAL(BCLog::LogEscapeMessage("Message\n with newlines\n"), "Message\n with newlines\n"); + // Other control characters are escaped in C syntax. + BOOST_CHECK_EQUAL(BCLog::LogEscapeMessage("\x01\x7f Corrupted log message\x0d"), R"(\x01\x7f Corrupted log message\x0d)"); + // Embedded NULL characters are escaped too. + const std::string NUL("O\x00O", 3); + BOOST_CHECK_EQUAL(BCLog::LogEscapeMessage(NUL), R"(O\x00O)"); +} + BOOST_AUTO_TEST_SUITE_END()