From owner-freebsd-questions@FreeBSD.ORG Wed Oct 12 10:58:13 2005 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id E7A6716A41F for ; Wed, 12 Oct 2005 10:58:13 +0000 (GMT) (envelope-from infofarmer@gmail.com) Received: from zproxy.gmail.com (zproxy.gmail.com [64.233.162.203]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8205943D46 for ; Wed, 12 Oct 2005 10:58:13 +0000 (GMT) (envelope-from infofarmer@gmail.com) Received: by zproxy.gmail.com with SMTP id z31so82132nzd for ; Wed, 12 Oct 2005 03:58:12 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=pvU8r4ZqglE6Li8qDdcuD49t/Ski0uHpXbkHI5evE08JYmRYyH1LhZNIqF7EphkbXyIVlWFkyziy0RXYVC2r+yHuGS2V0bAlExEVQ6iV0551FxE5fRBMPvEsfWzkWgJrdzk6PS9mC+KPTgBBb2ehB8wZUUWiXphUe1gE7UL0C3g= Received: by 10.37.15.64 with SMTP id s64mr728923nzi; Wed, 12 Oct 2005 03:58:12 -0700 (PDT) Received: by 10.37.20.34 with HTTP; Wed, 12 Oct 2005 03:58:12 -0700 (PDT) Message-ID: Date: Wed, 12 Oct 2005 14:58:12 +0400 From: "Andrew P." To: Jonathon McKitrick In-Reply-To: <20051012104241.GA34129@dogma.freebsd-uk.eu.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline References: <20051012104241.GA34129@dogma.freebsd-uk.eu.org> Cc: freebsd-questions@freebsd.org Subject: Re: Implementing software licensing in FreeBSD X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 12 Oct 2005 10:58:14 -0000 On 10/12/05, Jonathon McKitrick wrote: > > Setting aside opinions on copy protection and licensing, suppose I wanted= to > implement such a scheme. > > The key itself might be a network license, or an encrypted file containin= g > license info and system-specific info. But the real issue is how to prot= ect > the code that accesses the key. I know that 'wrappers' don't have much o= f an > application in Unix, and are actually impractical. But what techniques c= ould > be implemented within a library or archive that would make it difficult f= or > someone to trace the algorithm and/or make changes to the code to remove = the > protection checks? > > jm > -- > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.o= rg" > No matter what the platform is, one of the most effective tricks is to check different checksums (CRC, MD5, SHA256...) of different parts of different binaries at different (random) points by inline functions. Failure to verify a binary integrity should lead to immediate program termination. I don't see a single reason for this question being asked here.