Unintentional integer overflow

The expression's value may not be what the programmer intended, because the expression is evaluated using a narrow (i.e. few bits) integer type. An integer overflow occurs, with the result converted to a wider integer type
/src/conf/conf_compile.c:660: OVERFLOW_BEFORE_WIDEN 138678 Potentially overflowing expression "ccheck->key_id << shift" with type "u_int" (32 bits, unsigned) is evaluated using 32-bit arithmetic, and then used in a context that expects an expression of type "uint64_t" (64 bits, unsigned).