From: Nicolae Rosia Subject: IPSec hmac(sha256) truncation bits length Date: Wed, 4 Mar 2015 19:13:01 +0200 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Herbert Xu To: "linux-crypto@vger.kernel.org" Return-path: Received: from mail-la0-f53.google.com ([209.85.215.53]:41599 "EHLO mail-la0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932528AbbCDRND (ORCPT ); Wed, 4 Mar 2015 12:13:03 -0500 Received: by labgm9 with SMTP id gm9so6313773lab.8 for ; Wed, 04 Mar 2015 09:13:01 -0800 (PST) Sender: linux-crypto-owner@vger.kernel.org List-ID: Hello, I'm trying to understand why icv_truncbits is set to 96 for hmac(sha256) in xfrm_algo.c because RFC4868 [1] says that the truncation length for HMAC-SHA256 should be 128. Am I looking in the wrong place? [1] https://tools.ietf.org/html/rfc4868#section-2.6 Best regards, Nicolae Rosia