#include <string.h> /* Implements a constant time version of strcmp() * Will return 1 if a and b are equal, 0 if they are not */ int slow_equals(const char* a, const char* b) { size_t lena, lenb, diff, i; lena = strlen(a); lenb = strlen(b); diff = strlen(a) ^ strlen(b); for(i=0; i<lena && i<lenb; i++) { diff |= a[i] ^ b[i]; } if (diff == 0) { return 1; } else { return 0; } }