Merge pull request #2884 from gavinandresen/canonicalsizes2

Reject non-canonically-encoded CompactSize
This commit is contained in:
Gavin Andresen 2013-10-19 23:03:04 -07:00
commit f90b690a0d
3 changed files with 66 additions and 1 deletions

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@ -3677,7 +3677,6 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
{ {
vector<uint256> vWorkQueue; vector<uint256> vWorkQueue;
vector<uint256> vEraseQueue; vector<uint256> vEraseQueue;
CDataStream vMsg(vRecv);
CTransaction tx; CTransaction tx;
vRecv >> tx; vRecv >> tx;

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@ -216,18 +216,24 @@ uint64 ReadCompactSize(Stream& is)
unsigned short xSize; unsigned short xSize;
READDATA(is, xSize); READDATA(is, xSize);
nSizeRet = xSize; nSizeRet = xSize;
if (nSizeRet < 253)
throw std::ios_base::failure("non-canonical ReadCompactSize()");
} }
else if (chSize == 254) else if (chSize == 254)
{ {
unsigned int xSize; unsigned int xSize;
READDATA(is, xSize); READDATA(is, xSize);
nSizeRet = xSize; nSizeRet = xSize;
if (nSizeRet < 0x10000u)
throw std::ios_base::failure("non-canonical ReadCompactSize()");
} }
else else
{ {
uint64 xSize; uint64 xSize;
READDATA(is, xSize); READDATA(is, xSize);
nSizeRet = xSize; nSizeRet = xSize;
if (nSizeRet < 0x100000000LLu)
throw std::ios_base::failure("non-canonical ReadCompactSize()");
} }
if (nSizeRet > (uint64)MAX_SIZE) if (nSizeRet > (uint64)MAX_SIZE)
throw std::ios_base::failure("ReadCompactSize() : size too large"); throw std::ios_base::failure("ReadCompactSize() : size too large");

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@ -39,7 +39,67 @@ BOOST_AUTO_TEST_CASE(varints)
ss >> VARINT(j); ss >> VARINT(j);
BOOST_CHECK_MESSAGE(i == j, "decoded:" << j << " expected:" << i); BOOST_CHECK_MESSAGE(i == j, "decoded:" << j << " expected:" << i);
} }
}
BOOST_AUTO_TEST_CASE(compactsize)
{
CDataStream ss(SER_DISK, 0);
vector<char>::size_type i, j;
for (i = 1; i <= MAX_SIZE; i *= 2)
{
WriteCompactSize(ss, i-1);
WriteCompactSize(ss, i);
}
for (i = 1; i <= MAX_SIZE; i *= 2)
{
j = ReadCompactSize(ss);
BOOST_CHECK_MESSAGE((i-1) == j, "decoded:" << j << " expected:" << (i-1));
j = ReadCompactSize(ss);
BOOST_CHECK_MESSAGE(i == j, "decoded:" << j << " expected:" << i);
}
}
static bool isCanonicalException(const std::ios_base::failure& ex)
{
return std::string("non-canonical ReadCompactSize()") == ex.what();
}
BOOST_AUTO_TEST_CASE(noncanonical)
{
// Write some non-canonical CompactSize encodings, and
// make sure an exception is thrown when read back.
CDataStream ss(SER_DISK, 0);
vector<char>::size_type n;
// zero encoded with three bytes:
ss.write("\xfd\x00\x00", 3);
BOOST_CHECK_EXCEPTION(ReadCompactSize(ss), std::ios_base::failure, isCanonicalException);
// 0xfc encoded with three bytes:
ss.write("\xfd\xfc\x00", 3);
BOOST_CHECK_EXCEPTION(ReadCompactSize(ss), std::ios_base::failure, isCanonicalException);
// 0xfd encoded with three bytes is OK:
ss.write("\xfd\xfd\x00", 3);
n = ReadCompactSize(ss);
BOOST_CHECK(n == 0xfd);
// zero encoded with five bytes:
ss.write("\xfe\x00\x00\x00\x00", 5);
BOOST_CHECK_EXCEPTION(ReadCompactSize(ss), std::ios_base::failure, isCanonicalException);
// 0xffff encoded with five bytes:
ss.write("\xfe\xff\xff\x00\x00", 5);
BOOST_CHECK_EXCEPTION(ReadCompactSize(ss), std::ios_base::failure, isCanonicalException);
// zero encoded with nine bytes:
ss.write("\xff\x00\x00\x00\x00\x00\x00\x00\x00", 9);
BOOST_CHECK_EXCEPTION(ReadCompactSize(ss), std::ios_base::failure, isCanonicalException);
// 0x01ffffff encoded with nine bytes:
ss.write("\xff\xff\xff\xff\x01\x00\x00\x00\x00", 9);
BOOST_CHECK_EXCEPTION(ReadCompactSize(ss), std::ios_base::failure, isCanonicalException);
} }
BOOST_AUTO_TEST_SUITE_END() BOOST_AUTO_TEST_SUITE_END()