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Merge pull request #10561 from ethereum/abiv2-isabelle-values
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Abiv2 fuzzer: Make integer value generation consistent with range for…
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@bshastry
bshastry authored Dec 10, 2020
2 parents e15136c + 3c8caab commit fe79a27
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Showing 2 changed files with 94 additions and 54 deletions.
145 changes: 94 additions & 51 deletions test/tools/ossfuzz/protoToAbiV2.cpp
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Original file line number Diff line number Diff line change
@@ -1,10 +1,98 @@
#include <test/tools/ossfuzz/protoToAbiV2.h>

#include <boost/preprocessor.hpp>

/// Convenience macros
/// Returns a valid Solidity integer width w such that 8 <= w <= 256.
#define INTWIDTH(z, n, _ununsed) BOOST_PP_MUL(BOOST_PP_ADD(n, 1), 8)
/// Using declaration that aliases long boost multiprecision types with
/// s(u)<width> where <width> is a valid Solidity integer width and "s"
/// stands for "signed" and "u" for "unsigned".
#define USINGDECL(z, n, sign) \
using BOOST_PP_CAT(BOOST_PP_IF(sign, s, u), INTWIDTH(z, n,)) = \
boost::multiprecision::number< \
boost::multiprecision::cpp_int_backend< \
INTWIDTH(z, n,), \
INTWIDTH(z, n,), \
BOOST_PP_IF( \
sign, \
boost::multiprecision::signed_magnitude, \
boost::multiprecision::unsigned_magnitude \
), \
boost::multiprecision::unchecked, \
void \
> \
>;
/// Instantiate the using declarations for signed and unsigned integer types.
BOOST_PP_REPEAT(32, USINGDECL, 1)
BOOST_PP_REPEAT(32, USINGDECL, 0)
/// Case implementation that returns an integer value of the specified type.
/// For signed integers, we divide by two because the range for boost multiprecision
/// types is double that of Solidity integer types. Example, 8-bit signed boost
/// number range is [-255, 255] but Solidity `int8` range is [-128, 127]
#define CASEIMPL(z, n, sign) \
case INTWIDTH(z, n,): \
stream << BOOST_PP_IF( \
sign, \
integerValue< \
BOOST_PP_CAT( \
BOOST_PP_IF(sign, s, u), \
INTWIDTH(z, n,) \
)>(_counter) / 2, \
integerValue< \
BOOST_PP_CAT( \
BOOST_PP_IF(sign, s, u), \
INTWIDTH(z, n,) \
)>(_counter) \
); \
break;
/// Switch implementation that instantiates case statements for (un)signed
/// Solidity integer types.
#define SWITCHIMPL(sign) \
ostringstream stream; \
switch (_intWidth) \
{ \
BOOST_PP_REPEAT(32, CASEIMPL, sign) \
} \
return stream.str();

using namespace std;
using namespace solidity;
using namespace solidity::util;
using namespace solidity::test::abiv2fuzzer;

namespace
{
template <typename V>
static V integerValue(unsigned _counter)
{
V value = V(
u256(solidity::util::keccak256(solidity::util::h256(_counter))) % u256(boost::math::tools::max_value<V>())
);
if (value % 2 == 0)
return value * (-1);
else
return value;
}

static string signedIntegerValue(unsigned _counter, unsigned _intWidth)
{
SWITCHIMPL(1)
}

static string unsignedIntegerValue(unsigned _counter, unsigned _intWidth)
{
SWITCHIMPL(0)
}

static string integerValue(unsigned _counter, unsigned _intWidth, bool _signed)
{
if (_signed)
return signedIntegerValue(_counter, _intWidth);
else
return unsignedIntegerValue(_counter, _intWidth);
}
}

string ProtoConverter::getVarDecl(
string const& _type,
string const& _varName,
Expand Down Expand Up @@ -1013,11 +1101,7 @@ string ValueGetterVisitor::visit(BoolType const&)

string ValueGetterVisitor::visit(IntegerType const& _type)
{
return integerValueAsString(
_type.is_signed(),
getIntWidth(_type),
counter()
);
return integerValue(counter(), getIntWidth(_type), _type.is_signed());
}

string ValueGetterVisitor::visit(FixedByteType const& _type)
Expand All @@ -1041,48 +1125,6 @@ string ValueGetterVisitor::visit(DynamicByteArrayType const& _type)
);
}

std::string ValueGetterVisitor::integerValueAsString(bool _sign, unsigned _width, unsigned _counter)
{
if (_sign)
return intValueAsString(_width, _counter);
else
return uintValueAsString(_width, _counter);
}

/* Input(s)
* - Unsigned integer to be hashed
* - Width of desired uint value
* Processing
* - Take hash of first parameter and mask it with the max unsigned value for given bit width
* Output
* - string representation of uint value
*/
std::string ValueGetterVisitor::uintValueAsString(unsigned _width, unsigned _counter)
{
solAssert(
(_width % 8 == 0),
"Proto ABIv2 Fuzzer: Unsigned integer width is not a multiple of 8"
);
return maskUnsignedIntToHex(_counter, _width/4);
}

/* Input(s)
* - counter to be hashed to derive a value for Integer type
* - Width of desired int value
* Processing
* - Take hash of first parameter and mask it with the max signed value for given bit width
* Output
* - string representation of int value
*/
std::string ValueGetterVisitor::intValueAsString(unsigned _width, unsigned _counter)
{
solAssert(
(_width % 8 == 0),
"Proto ABIv2 Fuzzer: Signed integer width is not a multiple of 8"
);
return maskUnsignedIntToHex(_counter, ((_width/4) - 1));
}

std::string ValueGetterVisitor::croppedString(
unsigned _numBytes,
unsigned _counter,
Expand Down Expand Up @@ -1153,9 +1195,10 @@ std::string ValueGetterVisitor::fixedByteValueAsString(unsigned _width, unsigned

std::string ValueGetterVisitor::addressValueAsString(unsigned _counter)
{
return Whiskers(R"(address(<value>))")
("value", uintValueAsString(160, _counter))
.render();
// TODO: Isabelle encoder expects address literal to be exactly
// 20 bytes and a hex string.
// Example: 0x0102030405060708090a0102030405060708090a
return "address(" + maskUnsignedIntToHex(_counter, 40) + ")";
}

std::string ValueGetterVisitor::variableLengthValueAsString(
Expand Down
3 changes: 0 additions & 3 deletions test/tools/ossfuzz/protoToAbiV2.h
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Original file line number Diff line number Diff line change
Expand Up @@ -792,9 +792,6 @@ class ValueGetterVisitor: AbiV2ProtoVisitor<std::string>
return m_counter++;
}

static std::string intValueAsString(unsigned _width, unsigned _counter);
static std::string uintValueAsString(unsigned _width, unsigned _counter);
static std::string integerValueAsString(bool _sign, unsigned _width, unsigned _counter);
static std::string addressValueAsString(unsigned _counter);
static std::string fixedByteValueAsString(unsigned _width, unsigned _counter);

Expand Down

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