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Cleared UBsan error based on undefined shift. Tightened behaviors based on offline conversation with Wei and Denis. One shift error remains due to use of rotVariable by Cast. The UB will be cleared shortly, when specializations using GCC assembler is checked in

pull/35/head
Jeffrey Walton 2015-07-17 22:21:01 -04:00
parent cac038a855
commit 8cef820ac8
1 changed files with 26 additions and 12 deletions
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38
misc.h
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@ -685,40 +685,54 @@ CRYPTOPP_DLL void CRYPTOPP_API UnalignedDeallocate(void *p);
// Finally, if a specialization avoids the undefined behavior, then it
// does not assert.
// Well defined if y in [0,31], non-constant time due to branch
template <class T> inline T rotlFixed(T x, unsigned int y)
{
assert(y < sizeof(T)*8);
return y ? T((x<<y) | (x>>(sizeof(T)*8-y))) : x;
static const unsigned int THIS_SIZE = sizeof(T)*8;
assert(y < THIS_SIZE);
return y ? T((x<<y) | (x>>(THIS_SIZE-y))) : x;
}
// Well defined if y in [0,31], non-constant time due to branch
template <class T> inline T rotrFixed(T x, unsigned int y)
{
assert(y < sizeof(T)*8);
return y ? T((x>>y) | (x<<(sizeof(T)*8-y))) : x;
static const unsigned int THIS_SIZE = sizeof(T)*8;
assert(y < THIS_SIZE);
return y ? T((x>>y) | (x<<(THIS_SIZE-y))) : x;
}
// Well defined if y in [1,31], near constant time
template <class T> inline T rotlVariable(T x, unsigned int y)
{
assert(y < sizeof(T)*8);
return T((x<<y) | (x>>(sizeof(T)*8-y)));
static const unsigned int THIS_SIZE = sizeof(T)*8;
assert(y > 0 && y < THIS_SIZE);
y %= THIS_SIZE;
return T((x<<y) | (x>>(THIS_SIZE-y)));
}
// Well defined if y in [1,31], near constant time
template <class T> inline T rotrVariable(T x, unsigned int y)
{
assert(y < sizeof(T)*8);
return T((x>>y) | (x<<(sizeof(T)*8-y)));
static const unsigned int THIS_SIZE = sizeof(T)*8;
assert(y > 0 && y < THIS_SIZE);
y %= THIS_SIZE;
return T((x>>y) | (x<<(THIS_SIZE-y)));
}
// Well defined for all y, near constant time
template <class T> inline T rotlMod(T x, unsigned int y)
{
y %= sizeof(T)*8;
return T((x<<y) | (x>>((sizeof(T)*8-y) % (sizeof(T)*8))));
static const unsigned int THIS_SIZE = sizeof(T)*8;
y %= THIS_SIZE;
return T((x<<y) | (x>>((THIS_SIZE-y) % THIS_SIZE)));
}
// Well defined for all y, near constant time
template <class T> inline T rotrMod(T x, unsigned int y)
{
y %= sizeof(T)*8;
return T((x>>y) | (x<<((sizeof(T)*8-y) % (sizeof(T)*8))));
static const unsigned int THIS_SIZE = sizeof(T)*8;
y %= THIS_SIZE;
return T((x>>y) | (x<<((THIS_SIZE-y) % THIS_SIZE)));
}
#ifdef _MSC_VER