No - Hamas did and does commit war crimes. There's less ambiguity there. Taking of hostages, deliberately killing civilians, atrocities involved in the attack, indiscriminate rocket launches, and using civilians as human shields. All these are well documented, and some are repeats of past actions declared as war crimes, or possible war crimes.
Israel's actions are more in line with international law - as much as some posters are reluctant to accept, and despite the usual comments from human rights organizations, pro-Palestinians commentators and so on.
There's a history of several past rounds of fighting to draw on.