Fernando,

Parece-me que é justamente o argumento que você dá (dificuldade na
tradução e escassês de tempo) que forçaram o Paulo Gustavo a enviar a
matéria em inglês. Em outras palavras: todos têm problemas
semelhantes.

Mas para facilitar, traduzo o assunto: "Fonte aberto x fonte fechado".
Discorre sobre as diferenças entre as duas modalidades de código de
programação usados hoje em dia. Muita gente aqui na lista não têm
interesse no assunto. Os que tiverem podem fazer um esforcinho e
traduzi-lo. Ou então pedir ajuda.

Roger Chadel

A respeito de [VotoEletronico] Re: Open Source x Closed Source,
em 21/02/2006, 11:07, fernando gonçalves escreveu:

fg> Olá Paulo 
fg>    Paz e Bem
fg>    
fg>   Queira inviar mensagem em Português.
fg>    
fg>   Obrigado.
fg>    
fg>   At. Dificuldade na tradução e escasses de tempo justificam o pedido.
fg>    
fg>   

fg> Paulo Gustavo Sampaio Andrade <[EMAIL PROTECTED]> escreveu:
fg>   Wide Open Source
fg> Elias Levy, SecurityFocus 2000-04-17

fg> Is Open Source really more secure than closed? Elias Levy says
fg> there's a little security in obscurity. 

fg> One of the great rallying cries from the Open Source community is
fg> the assertion that Open Source Software (OSS) is, by its very
fg> nature, less likely to contain security vulnerabilities, including
fg> back doors, than closed source software. The reality is far more complex 
and nuanced.

fg> Advocates derive their dogmatic!  faith  in the implicit security
fg> of Open Source code from the concept of "peer review," a
fg> cornerstone of the scientific process in which published papers
fg> and theories are scrutinized by experts other than the authors.
fg> The more peers that review the work, the less likely it is that it
fg> will contains errors, and the more likely it is to become accepted.

fg> Open Source apostles believe that releasing the source code for a
fg> piece of software subjects it to the same kind of peer review as a
fg> quantum physics theory published in a scientific journal. Other
fg> programmers, the theory goes, will review the code for security
fg> vulnerabilities, reveal and fix them, and thus the number of new
fg> vulnerabilities introduced and discovered in the software will
fg> decrease over time when compared to similar closed source software.

fg> It's a nice theory, and in the ideal Open Source world, it would
fg> even be true. But in the real world, there are a variety of
fg> factors that effect how secure Open Source Softwa! re  really is.

fg> Sure, the source code is available. But is anyone reading it?

fg> If Open Source were the panacea some think it is, then every
fg> security hole described, fixed and announced to the public would
fg> come from people analyzing the source code for security
fg> vulnerabilities, such as the folks at OpenBSD, the Linux Auditing
fg> Project, or the developers or users of the application.

fg> But there have been plenty of security vulnerabilities in Open
fg> Source Software that were discovered, not by peer review, but by
fg> black hats. Some security holes aren't discovered by the good guys
fg> until an attacker's tools are found on a compromised site, network
fg> traffic captured during an intrusion turns up signs of the
fg> exploit, or knowledge of the bug finally bubbles up from the underground.

fg> Why is this? When the security company Trusted Information
fg> Systems (TIS) began making the source code of their Gauntlet
fg> firewall available to their customers many years ago, they
fg> believed th! at  their clients would check for themselves how
fg> secure the product was. What they found instead was that very few
fg> people outside of TIS ever sent in feedback, bug reports or
fg> vulnerabilities. Nobody, it seems, is reading the source.

fg> The fact is, most open source users run the software, but don't
fg> personally read the code. They just assume that someone else will
fg> do the auditing for them, and too often, it's the bad guys.

fg> Even if people are reviewing the code, that doesn't mean they're qualified 
to do so.

fg> In the scientific world, peer review works because the people
fg> doing the reviewing possess a comparable, or higher, technical
fg> caliber and level of authority on the subject matter than the author.

fg> It is generally true that the more people reviewing a piece of
fg> code, the less likely it is the code will have a security flaw.
fg> But a single well-trained reviewer who understands security and
fg> what the code is trying to accomplish will be more effective than
fg> a hund! red  people who just recently learned how to program.

fg> It is easy to hide vulnerabilities in complex, little understood and 
undocumented source code.

fg> Old versions of the Sendmail mail transport agent implemented a
fg> DEBUG SMTP command that allowed the connecting user to specify a
fg> set of commands instead of an email address to receive the
fg> message. This was one of the vulnerabilities exploited by the notorious 
Morris Internet worm.

fg> Sendmail is one of the oldest examples of open source software,
fg> yet this vulnerability, and many others, lay unfixed a long time.
fg> For years Sendmail was plagued by security problems, because this
fg> monolithic programs was very large, complicated, and little understood but 
for a few.

fg> Vulnerabilities can be a lot more subtle than the Sendmail DEBUG
fg> command. How many people really understand the ins and outs of a
fg> kernel based NFS server? Are we sure its not leaking file handles
fg> in some instances? Ssh 1.2.27 is over seventy-one thousand!  lines
fg> of code (client and server). Are we sure a subtle flaw does not
fg> weakening its key strength to only 40-bits?

fg> There is no strong guarantee that source code and binaries of an
fg> application have any real relationship.

fg> All the benefits of source code peer review are irrelevant if you
fg> can not be certain that a given binary application is the result of the 
reviewed source code.

fg> Ken Thompson made this very clear during his 1983 Turing Award
fg> lecture to the ACM, in which he revealed a shocking, and subtle,
fg> software subversion technique that's still illustrative seventeen years 
later.

fg> Thompson modified the UNIX C compiler to recognize when the login
fg> program was being compiled, and to insert a back door in the
fg> resulting binary code such that it would allow him to login as any user 
using a "magic" password.

fg> Anyone reviewing the compiler source code could have found the
fg> back door, except that Thompson then modified the compiler so that
fg> whenever it compiled  itself, it would insert both the code that
fg> inserts the login back door, as well as code that modifies the
fg> compiler. With this new binary he removed the modifications he had made and 
recompiled again.

fg> He now had a trojaned compiler and clean source code. Anyone
fg> using his compiler to compile either the login program , or the
fg> compiler, would propagate his back doors.

fg> The reason his attack worked is because the compiler has a
fg> bootstrapping problem. You need a compiler to compile the
fg> compiler. You must obtain a binary copy of the compiler before you
fg> can use it to translate the compiler source code into a binary.
fg> There was no guarantee that the binary compiler you were using was
fg> really related to the source code of the same.

fg> Most applications do not have this bootstrapping problem. But how
fg> many users of open source software compile all of their applications from 
source?

fg> A great number of open source users install precompiled software
fg> distributions such a! s those  from RedHat or Debian from CD-ROMs
fg> or FTP sites without thinking twice whether the binary
fg> applications have any real relationship to their source code.

fg> While some of the binaries are cryptographically signed to verify
fg> the identity of the packager, they make no other guarantees. Until
fg> the day comes when a trusted distributor of binary open source
fg> software can issue a strong cryptographic guarantee that a
fg> particular binary is the result of a given source, any security
fg> expectations one may have about the source can't be transferred to the 
binary.

fg> Open Source makes it easy for the bad guys to find vulnerabilities.

fg> Whatever potential Open Source has to make it easy for the good
fg> guys to proactively find security vulnerabilities, also goes to the bad 
guys.

fg> It is true that a black hat can find vulnerabilities in a
fg> binary-only application, and that they can attempt to steal the
fg> source code to the application from its closed source. But in the
fg> same amount of!  time  they can do that, they can audit ten
fg> different open source applications for vulnerabilities. A bad guy
fg> that can operate a hex editor can probably manage to grep source code for 
'strcpy'.

fg> Security through obscurity is not something you should depend on,
fg> but it can be an effective deterrent if the attacker can find an easier 
target.

fg> So does all this mean Open Source Software is no better than
fg> closed source software when it comes to security vulnerabilities?
fg> No. Open Source Software certainly does have the potential to be
fg> more secure than its closed source counterpart.

fg> But make no mistake, simply being open source is no guarantee of security.

fg> Fonte: http://www.securityfocus.com/news/19


fg>  

fg>  Yahoo! Search
fg>  Dê uma espiadinha e saiba tudo sobre o Big Brother Brasil. 



-- 
Grande abraço,

Roger Chadel

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Extraido de minha coleção de taglines:
Era tão azarado que, se quisesse achar uma agulha no palheiro, era só sentar-se 
nele.

 /"\
 \ /  Campanha da fita ASCII - contra mail html
  X   ASCII ribbon campaign - against html mail
 / \

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