Implement generic tryTo for string to boolean converions (#4689)

Implement generic `tryTo` for string to boolean converions
Also use it in some obvious placed in codebase

osquery/core/conversions.cpp

@@ -10,10 +10,12 @@
 
 #include <iomanip>
 #include <locale>
+#include <unordered_map>
 
 #include <boost/archive/iterators/base64_from_binary.hpp>
 #include <boost/archive/iterators/binary_from_base64.hpp>
 #include <boost/archive/iterators/transform_width.hpp>
+#include <boost/io/detail/quoted_manip.hpp>
 #if (BOOST_VERSION >= 106600)
 #include <boost/uuid/detail/sha1.hpp>
 #else
@@ -418,4 +420,42 @@ std::string getBufferSHA1(const char* buffer, size_t size) {
 size_t operator"" _sz(unsigned long long int x) {
   return x;
 }
+
+namespace impl {
+
+Expected<bool, ConversionError> stringToBool(std::string from) {
+  static const auto table = std::unordered_map<std::string, bool>{
+      {"1", true},
+      {"0", false},
+      {"y", true},
+      {"yes", true},
+      {"n", false},
+      {"no", false},
+      {"t", true},
+      {"true", true},
+      {"f", false},
+      {"false", false},
+      {"ok", true},
+      {"disable", false},
+      {"enable", true},
+  };
+  using CharType = std::string::value_type;
+  // Classic locale could be used here because all available string
+  // representations of boolean have ascii encoding. It must be a bit faster.
+  static const auto& ctype =
+      std::use_facet<std::ctype<CharType>>(std::locale::classic());
+  for (auto& ch : from) {
+    ch = ctype.tolower(ch);
+  }
+  const auto it = table.find(from);
+  if (it == table.end()) {
+    return createError(ConversionError::InvalidArgument,
+                       "Wrong string representation of boolean ")
+           << boost::io::quoted(from);
+  }
+  return it->second;
 }
+
+} // namespace impl
+
+} // namespace osquery

osquery/core/conversions.h

@@ -322,4 +322,28 @@ inline typename std::enable_if<
 tryTo(FromType&& from) {
   return std::forward<FromType>(from);
 }
+
+namespace impl {
+
+Expected<bool, ConversionError> stringToBool(std::string from);
+
+} // namespace impl
+
+/**
+ * Parsing general representation of boolean value in string.
+ *     "1" : true
+ *     "0" : false
+ *     "y" : true
+ *   "yes" : true
+ *     "n" : false
+ *    "no" : false
+ *   ... and so on
+ *   For the full list of possible valid values @see stringToBool definition
+ */
+template <typename ToType>
+inline typename std::enable_if<std::is_same<ToType, bool>::value,
+                               Expected<ToType, ConversionError>>::type
+tryTo(std::string from) {
+  return impl::stringToBool(std::move(from));
+}
 }

osquery/core/tests/conversions_tests.cpp

@@ -324,4 +324,45 @@ TEST_F(ConversionsTests, tryTo_same_type) {
   auto ret2 = tryTo<First>(const_test_lvalue);
   ASSERT_FALSE(ret2.isError());
 }
+
+TEST_F(ConversionsTests, tryTo_string_to_boolean_valid_args) {
+  const auto test_table = std::unordered_map<std::string, bool>{
+      {"1", true},        {"0", false},       {"y", true},
+      {"n", false},       {"yes", true},      {"yEs", true},
+      {"Yes", true},      {"no", false},      {"No", false},
+      {"t", true},        {"T", true},        {"f", false},
+      {"F", false},       {"true", true},     {"True", true},
+      {"tRUE", true},     {"false", false},   {"fALse", false},
+      {"ok", true},       {"OK", true},       {"Ok", true},
+      {"enable", true},   {"Enable", true},   {"ENABLE", true},
+      {"disable", false}, {"Disable", false}, {"DISABLE", false},
+  };
+  for (const auto& argAndAnswer : test_table) {
+    auto exp = tryTo<bool>(argAndAnswer.first);
+    ASSERT_FALSE(exp.isError());
+    EXPECT_EQ(argAndAnswer.second, exp.get());
+  }
+}
+
+TEST_F(ConversionsTests, tryTo_string_to_boolean_invalid_args) {
+  const auto test_table = std::vector<std::string>{
+      "",       "\0",      "\n",      "\x06",  "\x15",   "\x27",     "ADS",
+      "7251",   "20.09",   "M0V+K7V", "+",     "-",      ".",        "@",
+      "1.0",    "11",      "00",      " 0",    "1 ",     "2",        "10",
+      "100%",   "_0",      "1_",      "1.",    "2.",     "E",        "a",
+      "b",      "d",       "e",       "o",     "p",      "uh",       "nix",
+      "nixie",  "nixy",    "nixey",   "nay",   "nah",    "no way",   "veto",
+      "yea",    "yeah",    "yep",     "okey",  "aye",    "roger",    "uh-huh",
+      "righto", "yup",     "yuppers", "ja",    "surely", "amen",     "totally",
+      "sure",   "yessir",  "true.",   "tru",   "tr",     "tr.",      "ff",
+      "yy",     "nn",      "nope",    "null",  "nil",    "dis",      "able",
+      "pos",    "neg",     "ack",     "ACK",   "NAK",    "enabled",  "disabled",
+      "valid",  "invalid", "void",    "allow", "permit", "positive", "negative",
+  };
+  for (const auto& wrong : test_table) {
+    auto exp = tryTo<bool>(wrong);
+    ASSERT_TRUE(exp.isError());
+    EXPECT_EQ(ConversionError::InvalidArgument, exp.getErrorCode());
+  }
+}
 } // namespace osquery

osquery/devtools/shell.cpp

@@ -38,6 +38,7 @@
 #include <osquery/packs.h>
 #include <osquery/registry_factory.h>
 
+#include "osquery/core/conversions.h"
 #include "osquery/core/process.h"
 #include "osquery/devtools/devtools.h"
 #include "osquery/filesystem/fileops.h"
@@ -1049,15 +1050,12 @@ static int booleanValue(char* zArg) {
   if (i > 0 && zArg[i] == 0) {
     return static_cast<int>(integerValue(zArg) & 0xffffffff);
   }
-  if (sqlite3_stricmp(zArg, "on") == 0 || sqlite3_stricmp(zArg, "yes") == 0) {
-    return 1;
+  auto expected = osquery::tryTo<bool>(std::string{zArg});
+  if (expected.isError()) {
+    fprintf(
+        stderr, "ERROR: Not a boolean value: \"%s\". Assuming \"no\".\n", zArg);
   }
-  if (sqlite3_stricmp(zArg, "off") == 0 || sqlite3_stricmp(zArg, "no") == 0) {
-    return 0;
-  }
-  fprintf(
-      stderr, "ERROR: Not a boolean value: \"%s\". Assuming \"no\".\n", zArg);
-  return 0;
+  return expected.get_or(false) ? 1 : 0;
 }
 
 inline void meta_tables(int nArg, char** azArg) {

osquery/tables/applications/browser_utils.h

@@ -19,6 +19,7 @@
 #pragma warning(pop)
 #endif
 
+#include <osquery/core/conversions.h>
 #include <osquery/filesystem.h>
 #include <osquery/tables.h>
 
@@ -33,10 +34,9 @@ QueryData genChromeBasedExtensions(QueryContext& context,
 
 /// A helper check to rename bool-type values as 1 or 0.
 inline void jsonBoolAsInt(std::string& s) {
-  if (s == "true" || s == "YES" || s == "Yes") {
-    s = "1";
-  } else if (s == "false" || s == "NO" || s == "No") {
-    s = "0";
+  auto expected = tryTo<bool>(s);
+  if (!expected.isError()) {
+    s = expected.get() ? "1" : "0";
   }
 }
 }