On Tue, Aug 05, 2025 at 09:40:14PM +0200, Florian Westphal wrote:
> Now that we support non-constant RHS side in binary operations,
> reject XOR with non-constant key: we cannot transfer the expression.
>
> Fixes: 54bfc38c522b ("src: allow binop expressions with variable right-hand operands")
> Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Reviewed-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Maybe a tests/py for this to improve coverage is worth?
> ---
> I suggest to defer this until after 1.1.4 is out.
>
> src/evaluate.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/src/evaluate.c b/src/evaluate.c
> index 81e88d11aecb..1d102f842df0 100644
> --- a/src/evaluate.c
> +++ b/src/evaluate.c
> @@ -2578,16 +2578,20 @@ static int binop_can_transfer(struct eval_ctx *ctx,
>
> switch (left->op) {
> case OP_LSHIFT:
> + assert(left->right->etype == EXPR_VALUE);
> + assert(right->etype == EXPR_VALUE);
> +
> if (mpz_scan1(right->value, 0) < mpz_get_uint32(left->right->value))
> return expr_binary_error(ctx->msgs, right, left,
> "Comparison is always false");
> return 1;
> case OP_RSHIFT:
> + assert(left->right->etype == EXPR_VALUE);
> if (ctx->ectx.len < right->len + mpz_get_uint32(left->right->value))
> ctx->ectx.len += mpz_get_uint32(left->right->value);
> return 1;
> case OP_XOR:
> - return 1;
> + return expr_is_constant(left->right);
> default:
> return 0;
> }
> --
> 2.49.1
>
>
