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Avoid undefined behaviour in scriptnum tests. 

Signed-off-by: Daira Hopwood <daira@jacaranda.org>
This commit is contained in:
Daira Hopwood 2020-09-30 15:55:44 +01:00
parent b165ead16a
commit 9ba10a8071
2 changed files with 75 additions and 35 deletions
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14
src/test/scriptnum10.h
View File

@ -130,6 +130,13 @@ public:
if(value == 0)
return std::vector<unsigned char>();
// This could result in undefined behaviour in Bitcoin 0.10.0 and
// Zcash prior to https://github.com/zcash/zcash/pull/4454 .
// Since we only use this implementation for tests, we just assert
// that the tests are not triggering this case (which is tested
// separately for the real implementation).
assert(value != INT64_MIN);
std::vector<unsigned char> result;
const bool neg = value < 0;
uint64_t absvalue = neg ? -value : value;
@ -164,6 +171,13 @@ private:
if (vch.empty())
return 0;
// This could result in undefined behaviour in Bitcoin 0.10.0 and
// Zcash prior to https://github.com/zcash/zcash/pull/4454 .
// Since we only use this implementation for tests, we just assert
// that the tests are not triggering this case (which is tested
// separately for the real implementation).
assert(vch.size() <= 8);
int64_t result = 0;
for (size_t i = 0; i != vch.size(); ++i)
result |= static_cast<int64_t>(vch[i]) << 8*i;

96
src/test/scriptnum_tests.cpp
View File

@ -13,9 +13,24 @@
BOOST_FIXTURE_TEST_SUITE(scriptnum_tests, BasicTestingSetup)
static const int64_t values[] = \
{ 0, 1, CHAR_MIN, CHAR_MAX, UCHAR_MAX, SHRT_MIN, USHRT_MAX, INT_MIN, INT_MAX, UINT_MAX, LONG_MIN, LONG_MAX };
{ 0, 1, CHAR_MIN, CHAR_MAX, UCHAR_MAX, SHRT_MIN, USHRT_MAX, INT_MIN, INT_MAX, UINT_MAX, INT64_MIN, INT64_MAX };
static const int64_t offsets[] = { 1, 0x79, 0x80, 0x81, 0xFF, 0x7FFF, 0x8000, 0xFFFF, 0x10000};
static bool addition_in_range(int64_t a, int64_t b) {
// intentionally excludes cases where the result would be INT64_MIN
return b > 0 ? (a <= INT64_MAX - b) : (a > INT64_MIN - b);
}
static bool subtraction_in_range(int64_t a, int64_t b) {
// intentionally excludes cases where the result would be INT64_MIN
return b >= 0 ? (a > INT64_MIN + b) : (a <= INT64_MAX + b);
}
static bool value_in_range(int64_t a) {
return a != INT64_MIN;
}
static bool verify(const CScriptNum10& bignum, const CScriptNum& scriptnum)
{
return bignum.getvch() == scriptnum.getvch() && bignum.getint() == scriptnum.getint();
@ -27,11 +42,11 @@ static void CheckCreateVch(const int64_t& num)
CScriptNum scriptnum(num);
BOOST_CHECK(verify(bignum, scriptnum));
std::vector<unsigned char> vch = bignum.getvch();
CScriptNum10 bignum2(bignum.getvch(), false);
vch = scriptnum.getvch();
CScriptNum scriptnum2(scriptnum.getvch(), false);
std::vector<unsigned char> scriptnum_vch = scriptnum.getvch();
// The 9-byte case is exercised by the 'intmin' test.
BOOST_CHECK(scriptnum_vch.size() <= 8);
CScriptNum scriptnum2(scriptnum_vch, false);
BOOST_CHECK(verify(bignum2, scriptnum2));
CScriptNum10 bignum3(scriptnum2.getvch(), false);
@ -61,10 +76,7 @@ static void CheckAdd(const int64_t& num1, const int64_t& num2)
CScriptNum scriptnum3(num1);
CScriptNum scriptnum4(num1);
// int64_t overflow is undefined.
bool invalid = (((num2 > 0) && (num1 > (std::numeric_limits<int64_t>::max() - num2))) ||
((num2 < 0) && (num1 < (std::numeric_limits<int64_t>::min() - num2))));
if (!invalid)
if (addition_in_range(num1, num2))
{
BOOST_CHECK(verify(bignum1 + bignum2, scriptnum1 + scriptnum2));
BOOST_CHECK(verify(bignum1 + bignum2, scriptnum1 + num2));
@ -77,9 +89,7 @@ static void CheckNegate(const int64_t& num)
const CScriptNum10 bignum(num);
const CScriptNum scriptnum(num);
// -INT64_MIN is undefined
if (num != std::numeric_limits<int64_t>::min())
BOOST_CHECK(verify(-bignum, -scriptnum));
BOOST_CHECK(verify(-bignum, -scriptnum));
}
static void CheckSubtract(const int64_t& num1, const int64_t& num2)
@ -90,18 +100,13 @@ static void CheckSubtract(const int64_t& num1, const int64_t& num2)
const CScriptNum scriptnum2(num2);
bool invalid = false;
// int64_t overflow is undefined.
invalid = ((num2 > 0 && num1 < std::numeric_limits<int64_t>::min() + num2) ||
(num2 < 0 && num1 > std::numeric_limits<int64_t>::max() + num2));
if (!invalid)
if (subtraction_in_range(num1, num2))
{
BOOST_CHECK(verify(bignum1 - bignum2, scriptnum1 - scriptnum2));
BOOST_CHECK(verify(bignum1 - bignum2, scriptnum1 - num2));
}
invalid = ((num1 > 0 && num2 < std::numeric_limits<int64_t>::min() + num1) ||
(num1 < 0 && num2 > std::numeric_limits<int64_t>::max() + num1));
if (!invalid)
if (subtraction_in_range(num2, num1))
{
BOOST_CHECK(verify(bignum2 - bignum1, scriptnum2 - scriptnum1));
BOOST_CHECK(verify(bignum2 - bignum1, scriptnum2 - num1));
@ -170,9 +175,15 @@ BOOST_AUTO_TEST_CASE(creation)
{
for(size_t j = 0; j < sizeof(offsets) / sizeof(offsets[0]); ++j)
{
RunCreate(values[i]);
RunCreate(values[i] + offsets[j]);
RunCreate(values[i] - offsets[j]);
if (value_in_range(values[i])) {
RunCreate(values[i]);
}
if (addition_in_range(values[i], offsets[j])) {
RunCreate(values[i] + offsets[j]);
}
if (subtraction_in_range(values[i], offsets[j])) {
RunCreate(values[i] - offsets[j]);
}
}
}
}
@ -181,20 +192,35 @@ BOOST_AUTO_TEST_CASE(operators)
{
for(size_t i = 0; i < sizeof(values) / sizeof(values[0]); ++i)
{
for(size_t j = 0; j < sizeof(offsets) / sizeof(offsets[0]); ++j)
for (size_t j = 0; j < sizeof(values) / sizeof(values[0]); ++j)
{
RunOperators(values[i], values[i]);
RunOperators(values[i], -values[i]);
RunOperators(values[i], values[j]);
RunOperators(values[i], -values[j]);
RunOperators(values[i] + values[j], values[j]);
RunOperators(values[i] + values[j], -values[j]);
RunOperators(values[i] - values[j], values[j]);
RunOperators(values[i] - values[j], -values[j]);
RunOperators(values[i] + values[j], values[i] + values[j]);
RunOperators(values[i] + values[j], values[i] - values[j]);
RunOperators(values[i] - values[j], values[i] + values[j]);
RunOperators(values[i] - values[j], values[i] - values[j]);
if (value_in_range(values[i]))
{
RunOperators(values[i], values[i]);
RunOperators(values[i], -values[i]);
}
if (value_in_range(values[i]) && value_in_range(values[j]))
{
RunOperators(values[i], values[j]);
RunOperators(values[i], -values[j]);
}
if (addition_in_range(values[i], values[j]) && value_in_range(values[j]))
{
RunOperators(values[i] + values[j], values[j]);
RunOperators(values[i] + values[j], -values[j]);
RunOperators(values[i] + values[j], values[i] + values[j]);
}
if (subtraction_in_range(values[i], values[j]) && value_in_range(values[j]))
{
RunOperators(values[i] - values[j], values[j]);
RunOperators(values[i] - values[j], -values[j]);
RunOperators(values[i] - values[j], values[i] - values[j]);
}
if (addition_in_range(values[i], values[j]) && subtraction_in_range(values[i], values[j]))
{
RunOperators(values[i] + values[j], values[i] - values[j]);
RunOperators(values[i] - values[j], values[i] + values[j]);
}
}
}
}