/* -*-c-*-
*
- * $Id: idea.c,v 1.3 2000/07/02 18:24:39 mdw Exp $
+ * $Id: idea.c,v 1.4 2000/07/15 17:47:58 mdw Exp $
*
* Implementation of the IDEA cipher
*
/*----- Revision history --------------------------------------------------*
*
* $Log: idea.c,v $
+ * Revision 1.4 2000/07/15 17:47:58 mdw
+ * Fix bug in decryption key scheduling.
+ *
* Revision 1.3 2000/07/02 18:24:39 mdw
* Use a new multiplication function from an Ascom white paper to resist
* timing attacks.
{
uint32 m = 0x10001;
uint32 a = 1, b = 0;
+ uint32 nn = n;
+ if (!nn)
+ nn = 0x10000;
for (;;) {
uint32 q, r, t;
- if (!(r = m % n))
+ if (!(r = m % nn))
break;
- q = m / n;
- m = n; n = r;
+ q = m / nn;
+ m = nn; nn = r;
t = a; a = b - q * a; b = t;
}
if (a > MASK16)
ROUND(_k, _a, _b, _c, _d); \
ROUND(_k, _a, _c, _b, _d); \
MIX (_k, _a, _c, _b, _d); \
- c = (U16(_a) << 16) | U16(_c); \
- d = (U16(_b) << 16) | U16(_d); \
+ c = ((uint32)U16(_a) << 16) | (uint32)U16(_c); \
+ d = ((uint32)U16(_b) << 16) | (uint32)U16(_d); \
} while (0)
#define DBLK(k, a, b) EBLK((k), (a), (b))