Merge pull request #4293

fa126ef Avoid undefined behavior using CFlatData in CScript serialization (Wladimir J. van der Laan)
This commit is contained in:
Wladimir J. van der Laan 2014-06-23 10:38:42 +02:00
commit 5459116d61
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GPG key ID: 74810B012346C9A6
2 changed files with 38 additions and 4 deletions

View file

@ -770,12 +770,12 @@ public:
void Serialize(Stream &s, int nType, int nVersion) const {
std::vector<unsigned char> compr;
if (Compress(compr)) {
s << CFlatData(&compr[0], &compr[compr.size()]);
s << CFlatData(compr);
return;
}
unsigned int nSize = script.size() + nSpecialScripts;
s << VARINT(nSize);
s << CFlatData(&script[0], &script[script.size()]);
s << CFlatData(script);
}
template<typename Stream>
@ -784,13 +784,13 @@ public:
s >> VARINT(nSize);
if (nSize < nSpecialScripts) {
std::vector<unsigned char> vch(GetSpecialSize(nSize), 0x00);
s >> REF(CFlatData(&vch[0], &vch[vch.size()]));
s >> REF(CFlatData(vch));
Decompress(nSize, vch);
return;
}
nSize -= nSpecialScripts;
script.resize(nSize);
s >> REF(CFlatData(&script[0], &script[script.size()]));
s >> REF(CFlatData(script));
}
};

View file

@ -37,6 +37,34 @@ inline T& REF(const T& val)
return const_cast<T&>(val);
}
/** Get begin pointer of vector (non-const version).
* @note These functions avoid the undefined case of indexing into an empty
* vector, as well as that of indexing after the end of the vector.
*/
template <class T, class TAl>
inline T* begin_ptr(std::vector<T,TAl>& v)
{
return v.empty() ? NULL : &v[0];
}
/** Get begin pointer of vector (const version) */
template <class T, class TAl>
inline const T* begin_ptr(const std::vector<T,TAl>& v)
{
return v.empty() ? NULL : &v[0];
}
/** Get end pointer of vector (non-const version) */
template <class T, class TAl>
inline T* end_ptr(std::vector<T,TAl>& v)
{
return v.empty() ? NULL : (&v[0] + v.size());
}
/** Get end pointer of vector (const version) */
template <class T, class TAl>
inline const T* end_ptr(const std::vector<T,TAl>& v)
{
return v.empty() ? NULL : (&v[0] + v.size());
}
/////////////////////////////////////////////////////////////////
//
// Templates for serializing to anything that looks like a stream,
@ -318,6 +346,12 @@ protected:
char* pend;
public:
CFlatData(void* pbeginIn, void* pendIn) : pbegin((char*)pbeginIn), pend((char*)pendIn) { }
template <class T, class TAl>
explicit CFlatData(std::vector<T,TAl> &v)
{
pbegin = (char*)begin_ptr(v);
pend = (char*)end_ptr(v);
}
char* begin() { return pbegin; }
const char* begin() const { return pbegin; }
char* end() { return pend; }