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mirror of https://github.com/qpdf/qpdf.git synced 2024-11-11 07:30:57 +00:00
qpdf/libqpdf/JSON.cc
Jay Berkenbilt d71f05ca07 Fix sign and conversion warnings (major)
This makes all integer type conversions that have potential data loss
explicit with calls that do range checks and raise an exception. After
this commit, qpdf builds with no warnings when -Wsign-conversion
-Wconversion is used with gcc or clang or when -W3 -Wd4800 is used
with MSVC. This significantly reduces the likelihood of potential
crashes from bogus integer values.

There are some parts of the code that take int when they should take
size_t or an offset. Such places would make qpdf not support files
with more than 2^31 of something that usually wouldn't be so large. In
the event that such a file shows up and is valid, at least qpdf would
raise an error in the right spot so the issue could be legitimately
addressed rather than failing in some weird way because of a silent
overflow condition.
2019-06-21 13:17:21 -04:00

397 lines
8.7 KiB
C++

#include <qpdf/JSON.hh>
#include <qpdf/QUtil.hh>
#include <qpdf/QTC.hh>
#include <stdexcept>
JSON::Members::~Members()
{
}
JSON::Members::Members(PointerHolder<JSON_value> value) :
value(value)
{
}
JSON::JSON(PointerHolder<JSON_value> value) :
m(new Members(value))
{
}
JSON::JSON_value::~JSON_value()
{
}
JSON::JSON_dictionary::~JSON_dictionary()
{
}
std::string JSON::JSON_dictionary::unparse(size_t depth) const
{
std::string result = "{";
bool first = true;
for (std::map<std::string, PointerHolder<JSON_value> >::const_iterator
iter = members.begin();
iter != members.end(); ++iter)
{
if (first)
{
first = false;
}
else
{
result.append(1, ',');
}
result.append(1, '\n');
result.append(2 * (1 + depth), ' ');
result += ("\"" + (*iter).first + "\": " +
(*iter).second->unparse(1 + depth));
}
if (! first)
{
result.append(1, '\n');
result.append(2 * depth, ' ');
}
result.append(1, '}');
return result;
}
JSON::JSON_array::~JSON_array()
{
}
std::string JSON::JSON_array::unparse(size_t depth) const
{
std::string result = "[";
bool first = true;
for (std::vector<PointerHolder<JSON_value> >::const_iterator iter =
elements.begin();
iter != elements.end(); ++iter)
{
if (first)
{
first = false;
}
else
{
result.append(1, ',');
}
result.append(1, '\n');
result.append(2 * (1 + depth), ' ');
result += (*iter)->unparse(1 + depth);
}
if (! first)
{
result.append(1, '\n');
result.append(2 * depth, ' ');
}
result.append(1, ']');
return result;
}
JSON::JSON_string::JSON_string(std::string const& utf8) :
encoded(encode_string(utf8))
{
}
JSON::JSON_string::~JSON_string()
{
}
std::string JSON::JSON_string::unparse(size_t) const
{
return "\"" + encoded + "\"";
}
JSON::JSON_number::JSON_number(long long value) :
encoded(QUtil::int_to_string(value))
{
}
JSON::JSON_number::JSON_number(double value) :
encoded(QUtil::double_to_string(value, 6))
{
}
JSON::JSON_number::JSON_number(std::string const& value) :
encoded(value)
{
}
JSON::JSON_number::~JSON_number()
{
}
std::string JSON::JSON_number::unparse(size_t) const
{
return encoded;
}
JSON::JSON_bool::JSON_bool(bool val) :
value(val)
{
}
JSON::JSON_bool::~JSON_bool()
{
}
std::string JSON::JSON_bool::unparse(size_t) const
{
return value ? "true" : "false";
}
JSON::JSON_null::~JSON_null()
{
}
std::string JSON::JSON_null::unparse(size_t) const
{
return "null";
}
std::string
JSON::unparse() const
{
if (0 == this->m->value.getPointer())
{
return "null";
}
else
{
return this->m->value->unparse(0);
}
}
std::string
JSON::encode_string(std::string const& str)
{
std::string result;
size_t len = str.length();
for (size_t i = 0; i < len; ++i)
{
unsigned char ch = static_cast<unsigned char>(str.at(i));
switch (ch)
{
case '\\':
result += "\\\\";
break;
case '\"':
result += "\\\"";
break;
case '\b':
result += "\\b";
break;
case '\n':
result += "\\n";
break;
case '\r':
result += "\\r";
break;
case '\t':
result += "\\t";
break;
default:
if (ch < 32)
{
result += "\\u" + QUtil::int_to_string_base(ch, 16, 4);
}
else
{
result.append(1, static_cast<char>(ch));
}
}
}
return result;
}
JSON
JSON::makeDictionary()
{
return JSON(new JSON_dictionary());
}
JSON
JSON::addDictionaryMember(std::string const& key, JSON const& val)
{
JSON_dictionary* obj = dynamic_cast<JSON_dictionary*>(
this->m->value.getPointer());
if (0 == obj)
{
throw std::runtime_error(
"JSON::addDictionaryMember called on non-dictionary");
}
if (val.m->value.getPointer())
{
obj->members[encode_string(key)] = val.m->value;
}
else
{
obj->members[encode_string(key)] = new JSON_null();
}
return obj->members[encode_string(key)];
}
JSON
JSON::makeArray()
{
return JSON(new JSON_array());
}
JSON
JSON::addArrayElement(JSON const& val)
{
JSON_array* arr = dynamic_cast<JSON_array*>(
this->m->value.getPointer());
if (0 == arr)
{
throw std::runtime_error("JSON::addArrayElement called on non-array");
}
if (val.m->value.getPointer())
{
arr->elements.push_back(val.m->value);
}
else
{
arr->elements.push_back(new JSON_null());
}
return arr->elements.back();
}
JSON
JSON::makeString(std::string const& utf8)
{
return JSON(new JSON_string(utf8));
}
JSON
JSON::makeInt(long long int value)
{
return JSON(new JSON_number(value));
}
JSON
JSON::makeReal(double value)
{
return JSON(new JSON_number(value));
}
JSON
JSON::makeNumber(std::string const& encoded)
{
return JSON(new JSON_number(encoded));
}
JSON
JSON::makeBool(bool value)
{
return JSON(new JSON_bool(value));
}
JSON
JSON::makeNull()
{
return JSON(new JSON_null());
}
bool
JSON::checkSchema(JSON schema, std::list<std::string>& errors)
{
return checkSchemaInternal(this->m->value.getPointer(),
schema.m->value.getPointer(),
errors, "");
}
bool
JSON::checkSchemaInternal(JSON_value* this_v, JSON_value* sch_v,
std::list<std::string>& errors,
std::string prefix)
{
JSON_array* this_arr = dynamic_cast<JSON_array*>(this_v);
JSON_dictionary* this_dict = dynamic_cast<JSON_dictionary*>(this_v);
JSON_array* sch_arr = dynamic_cast<JSON_array*>(sch_v);
JSON_dictionary* sch_dict = dynamic_cast<JSON_dictionary*>(sch_v);
std::string err_prefix;
if (prefix.empty())
{
err_prefix = "top-level object";
}
else
{
err_prefix = "json key \"" + prefix + "\"";
}
if (sch_dict)
{
if (! this_dict)
{
QTC::TC("libtests", "JSON wanted dictionary");
errors.push_back(err_prefix + " is supposed to be a dictionary");
return false;
}
for (std::map<std::string, PointerHolder<JSON_value> >::iterator iter =
sch_dict->members.begin();
iter != sch_dict->members.end(); ++iter)
{
std::string const& key = (*iter).first;
if (this_dict->members.count(key))
{
checkSchemaInternal(
this_dict->members[key].getPointer(),
(*iter).second.getPointer(),
errors, prefix + "." + key);
}
else
{
QTC::TC("libtests", "JSON key missing in object");
errors.push_back(
err_prefix + ": key \"" + key +
"\" is present in schema but missing in object");
}
}
for (std::map<std::string, PointerHolder<JSON_value> >::iterator iter =
this_dict->members.begin();
iter != this_dict->members.end(); ++iter)
{
std::string const& key = (*iter).first;
if (sch_dict->members.count(key) == 0)
{
QTC::TC("libtests", "JSON key extra in object");
errors.push_back(
err_prefix + ": key \"" + key +
"\" is not present in schema but appears in object");
}
}
}
else if (sch_arr)
{
if (! this_arr)
{
QTC::TC("libtests", "JSON wanted array");
errors.push_back(err_prefix + " is supposed to be an array");
return false;
}
if (sch_arr->elements.size() != 1)
{
QTC::TC("libtests", "JSON schema array error");
errors.push_back(err_prefix +
" schema array contains other than one item");
return false;
}
int i = 0;
for (std::vector<PointerHolder<JSON_value> >::iterator iter =
this_arr->elements.begin();
iter != this_arr->elements.end(); ++iter, ++i)
{
checkSchemaInternal(
(*iter).getPointer(),
sch_arr->elements.at(0).getPointer(),
errors, prefix + "." + QUtil::int_to_string(i));
}
}
return errors.empty();
}