Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Implement parsing of nested regexp classes (issue #67) #69

Merged
merged 3 commits into from
Feb 25, 2020
Merged

Implement parsing of nested regexp classes (issue #67) #69

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
495895b
Fix handle of nested escaped regexp classes
TadeasKucera Feb 17, 2020
e5f3480
Fix handle of nested non-escaped classes
TadeasKucera Feb 17, 2020
0c380b8
Fix small code issues
TadeasKucera Feb 24, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 2 additions & 0 deletions include/yaramod/parser/parser_driver.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -180,7 +180,9 @@ class ParserDriver
std::string _indent; ///< Variable storing current indentation
std::string _comment; ///< For incremental construction of parsed comments
std::string _regexpClass; ///< Currently processed regular expression class.
std::size_t _regexpClassDepth = 0; ///< The rectangular brackets depth of nesting
pog::Parser<Value> _parser; ///< used pog parser

bool _sectionStrings = false; ///< flag used to determine if we parse section after 'strings:'
bool _escapedContent = false; ///< flag used to determine if a currently parsed literal contains hexadecimal byte (such byte must be unescaped in getPureText())

Expand Down
9 changes: 8 additions & 1 deletion include/yaramod/parser/value.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -21,6 +21,7 @@ namespace yaramod {

using RegexpRangePair = std::pair<std::optional<std::uint64_t>, std::optional<std::uint64_t>>;
using StringModifiers = std::vector<std::shared_ptr<StringModifier>>;
using RegexpClassRecord = std::pair<bool, std::string>;

/**
* Value is the type of all tokens produced by POG parser. Both token and rule actions return Value. The rule action parameters are also Values.
Expand Down Expand Up @@ -49,7 +50,8 @@ class Value
std::shared_ptr<RegexpUnit>,
std::vector<std::shared_ptr<RegexpUnit>>, //18
TokenIt,
RegexpRangePair //20
RegexpRangePair, //20
RegexpClassRecord
>;

/// @name Constructors
Expand Down Expand Up @@ -168,6 +170,11 @@ class Value
{
return std::move(moveValue<RegexpRangePair>());
}

RegexpClassRecord&& getRegexpClassRecord()
{
return std::move(moveValue<RegexpClassRecord>());
}
/// @}

protected:
Expand Down
36 changes: 30 additions & 6 deletions src/parser/parser_driver.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -365,23 +365,37 @@ void ParserDriver::defineTokens()
return std::string{str};
});
_parser.token(R"(\[\^\])").states("$regexp").enter_state("$regexp_class").action([&](std::string_view) -> Value {
_regexpClassDepth = 1;
_regexpClass = "^]";
return {};
});
_parser.token(R"(\[\])").states("$regexp").enter_state("$regexp_class").action([&](std::string_view) -> Value {
_regexpClassDepth = 1;
_regexpClass = "]";
return {};
});
_parser.token(R"(\[\^)").states("$regexp").enter_state("$regexp_class").action([&](std::string_view) -> Value {
_regexpClassDepth = 1;
_regexpClass = "^";
return {};
} );
_parser.token(R"(\[)").states("$regexp").enter_state("$regexp_class").action([&](std::string_view) -> Value {
_regexpClassDepth = 1;
_regexpClass.clear();
return {};
} );
_parser.token(R"(\])").states("$regexp_class").symbol("REGEXP_CLASS").description("regexp class").enter_state("$regexp").action([&](std::string_view) -> Value {
return _regexpClass;
_parser.token(R"(\])").states("$regexp_class").symbol("REGEXP_CLASS").description("regexp class").action([&](std::string_view) -> Value {
--_regexpClassDepth;
if(_regexpClassDepth == 0)
{
enter_state("$regexp");
return std::make_pair(true, _regexpClass);
}
else
{
_regexpClass += "]";
return std::make_pair(false, std::string{});
}
});
_parser.token(R"(\\w)").states("$regexp_class").action([&](std::string_view) -> Value { _regexpClass += "\\w"; return {};});
_parser.token(R"(\\W)").states("$regexp_class").action([&](std::string_view) -> Value { _regexpClass += "\\W"; return {};});
Expand All @@ -391,7 +405,14 @@ void ParserDriver::defineTokens()
_parser.token(R"(\\D)").states("$regexp_class").action([&](std::string_view) -> Value { _regexpClass += "\\D"; return {};});
_parser.token(R"(\\b)").states("$regexp_class").action([&](std::string_view) -> Value { _regexpClass += "\\b"; return {};});
_parser.token(R"(\\B)").states("$regexp_class").action([&](std::string_view) -> Value { _regexpClass += "\\B"; return {};});
_parser.token(R"([^]])").states("$regexp_class").action([&](std::string_view str) -> Value { _regexpClass += std::string{str}[0]; return {}; });
_parser.token(R"(\\\])").states("$regexp_class").action([&](std::string_view) -> Value { _regexpClass += "\\]"; --_regexpClassDepth; return {};});
_parser.token(R"(\\\[)").states("$regexp_class").action([&](std::string_view) -> Value { _regexpClass += "\\["; ++_regexpClassDepth; return {};});
_parser.token(R"(\[)").states("$regexp_class").action([&](std::string_view) -> Value {
++_regexpClassDepth;
_regexpClass += "[";
return {};
});
_parser.token(R"([^\]\[])").states("$regexp_class").action([&](std::string_view str) -> Value { _regexpClass += std::string{str}[0]; return {}; });
// $regexp end

_parser.end_token().states("@default", "$str", "$include", "$hexstr", "hexstr_jump", "$regexp", "$regexp_class").action([&](std::string_view) -> Value {
Expand Down Expand Up @@ -870,9 +891,12 @@ void ParserDriver::defineGrammar()
.production("REGEXP_NON_SPACE", [](auto&&) -> Value { return Value(std::make_shared<RegexpNonSpace>()); })
.production("REGEXP_DIGIT", [](auto&&) -> Value { return Value(std::make_shared<RegexpDigit>()); })
.production("REGEXP_NON_DIGIT", [](auto&&) -> Value { return Value(std::make_shared<RegexpNonDigit>()); })
.production("REGEXP_CLASS", [](auto&& args) -> Value {
std::string c = std::move(args[0].getString());
if (c[0] == '^')
.production("REGEXP_CLASS", [&](auto&& args) -> Value {
auto record = std::move(args[0].getRegexpClassRecord());
if (!record.first)
return Value(std::make_shared<RegexpText>(std::string{}));
auto c = record.second;
if (!c.empty() && c[0] == '^')
return std::make_shared<RegexpClass>(c.substr(1, c.length() - 1), true);
else
return std::make_shared<RegexpClass>(std::move(c), false);
Expand Down
80 changes: 80 additions & 0 deletions tests/cpp/parser_tests.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1110,6 +1110,86 @@ rule regexp_with_custom_negative_class
EXPECT_EQ(input_text, driver.getParsedFile().getTextFormatted());
}

TEST_F(ParserTests,
RegexpWithEscapedSquareBracketsInsideClassWorks) {
prepareInput(
R"(
rule regexp_with_escaped_square_brackets_inside_class
{
strings:
$1 = /[\[\]++]/
condition:
$1
}
)");

EXPECT_TRUE(driver.parse(input));
ASSERT_EQ(1u, driver.getParsedFile().getRules().size());

const auto& rule = driver.getParsedFile().getRules()[0];
EXPECT_EQ("regexp_with_escaped_square_brackets_inside_class", rule->getName());
EXPECT_EQ(Rule::Modifier::None, rule->getModifier());

auto strings = rule->getStrings();
ASSERT_EQ(1u, strings.size());

auto regexp = strings[0];
EXPECT_TRUE(regexp->isRegexp());
EXPECT_EQ("$1", regexp->getIdentifier());
EXPECT_EQ(R"(/[\[\]++]/)", regexp->getText());

EXPECT_EQ(input_text, driver.getParsedFile().getTextFormatted());
}

TEST_F(ParserTests,
RegexpWithUnescapedSquareBracketsInsideClassWorks) {
prepareInput(
R"(
rule regexp_with_unescaped_square_brackets_inside_class
{
strings:
$1 = /[[d][]***[abc]**][[]**]/
$2 = /[ !#()[\]{}*][ !#[\]+_]/
$3 = /[[\]*+]/
$4 = /[\[\]*+]/
condition:
all of them
}
)");

EXPECT_TRUE(driver.parse(input));
ASSERT_EQ(1u, driver.getParsedFile().getRules().size());

const auto& rule = driver.getParsedFile().getRules()[0];
EXPECT_EQ("regexp_with_unescaped_square_brackets_inside_class", rule->getName());
EXPECT_EQ(Rule::Modifier::None, rule->getModifier());

auto strings = rule->getStrings();
ASSERT_EQ(4u, strings.size());

auto regexp1 = strings[0];
EXPECT_TRUE(regexp1->isRegexp());
EXPECT_EQ("$1", regexp1->getIdentifier());
EXPECT_EQ(R"(/[[d][]***[abc]**][[]**]/)", regexp1->getText());

auto regexp2 = strings[1];
EXPECT_TRUE(regexp2->isRegexp());
EXPECT_EQ("$2", regexp2->getIdentifier());
EXPECT_EQ(R"(/[ !#()[\]{}*][ !#[\]+_]/)", regexp2->getText());

auto regexp3 = strings[2];
EXPECT_TRUE(regexp3->isRegexp());
EXPECT_EQ("$3", regexp3->getIdentifier());
EXPECT_EQ(R"(/[[\]*+]/)", regexp3->getText());

auto regexp = strings[3];
EXPECT_TRUE(regexp->isRegexp());
EXPECT_EQ("$4", regexp->getIdentifier());
EXPECT_EQ(R"(/[\[\]*+]/)", regexp->getText());

EXPECT_EQ(input_text, driver.getParsedFile().getTextFormatted());
}

TEST_F(ParserTests,
RegexpWithIterationWorks) {
prepareInput(
Expand Down