#include static int x; int main() { int *p0 = &x, *p1, *p2, *p3; unsigned long salt = 0; /* * With TBI enabled and a 48-bit VA, there are 7 bits of auth, and so * a 1/128 chance of auth = pac(ptr,key,salt) producing zero. * Find a salt that creates auth != 0. */ do { salt++; asm("pacda %0, %1" : "=r"(p1) : "r"(salt), "0"(p0)); } while (p0 == p1); /* * This pac must fail, because the input pointer bears an encryption, * and so is not properly extended within bits [55:47]. This will * toggle bit 54 in the output... */ asm("pacda %0, %1" : "=r"(p2) : "r"(salt), "0"(p1)); /* ... so that the aut must fail, setting bit 53 in the output ... */ asm("autda %0, %1" : "=r"(p3) : "r"(salt), "0"(p2)); /* ... which means this equality must not hold. */ assert(p3 != p0); return 0; }