[Bitcoin-development] bitcoin pull requests

[Bitcoin-development] bitcoin pull requests

[Melvin Carvalho]

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I was just looking at:

https://bitcointalk.org/index.php?topic=4571.0

I'm just curious if there is a possible attack vector here based on the
fact that git uses the relatively week SHA1

Could a seemingly innocuous pull request generate another file with a
backdoor/nonce combination that slips under the radar?

Apologies if this has come up before ...

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Re: [Bitcoin-development] bitcoin pull requests

[Petr Praus]

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An attacker would have to find a collision between two specific pieces of
code - his malicious code and a useful innoculous code that would be
accepted as pull request. This is the second, much harder case in the
birthday problem. When people talk about SHA-1 being broken they actually
mean the first case in the birthday problem - find any two arbitrary values
that hash to the same value. So, no I don't think it's a feasible attack
vector any time soon.

Besides, with that kind of hashing power, it might be more feasible to
cause problems in the chain by e.g. constantly splitting it.


On 1 April 2013 03:26, Melvin Carvalho <melvincarvalho@gmail.com> wrote:

> I was just looking at:
>
> https://bitcointalk.org/index.php?topic=4571.0
>
> I'm just curious if there is a possible attack vector here based on the
> fact that git uses the relatively week SHA1
>
> Could a seemingly innocuous pull request generate another file with a
> backdoor/nonce combination that slips under the radar?
>
> Apologies if this has come up before ...
>
>
> ------------------------------------------------------------------------------
> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
> Rise to greatness in Intel's independent game demo contest.
> Compete for recognition, cash, and the chance to get your game
> on Steam. $5K grand prize plus 10 genre and skill prizes.
> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
> _______________________________________________
> Bitcoin-development mailing list
> Bitcoin-development@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
>
>

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Re: [Bitcoin-development] bitcoin pull requests

[Melvin Carvalho]

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On 1 April 2013 20:28, Petr Praus <petr@praus.net> wrote:

> An attacker would have to find a collision between two specific pieces of
> code - his malicious code and a useful innoculous code that would be
> accepted as pull request. This is the second, much harder case in the
> birthday problem. When people talk about SHA-1 being broken they actually
> mean the first case in the birthday problem - find any two arbitrary values
> that hash to the same value. So, no I don't think it's a feasible attack
> vector any time soon.
>
> Besides, with that kind of hashing power, it might be more feasible to
> cause problems in the chain by e.g. constantly splitting it.
>

OK, maybe im being *way* too paranoid here ... but what if someone had
access to github, could they replace one file with one they had prepared at
some point?


>
>
> On 1 April 2013 03:26, Melvin Carvalho <melvincarvalho@gmail.com> wrote:
>
>> I was just looking at:
>>
>> https://bitcointalk.org/index.php?topic=4571.0
>>
>> I'm just curious if there is a possible attack vector here based on the
>> fact that git uses the relatively week SHA1
>>
>> Could a seemingly innocuous pull request generate another file with a
>> backdoor/nonce combination that slips under the radar?
>>
>> Apologies if this has come up before ...
>>
>>
>> ------------------------------------------------------------------------------
>> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
>> Rise to greatness in Intel's independent game demo contest.
>> Compete for recognition, cash, and the chance to get your game
>> on Steam. $5K grand prize plus 10 genre and skill prizes.
>> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
>> _______________________________________________
>> Bitcoin-development mailing list
>> Bitcoin-development@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
>>
>>
>

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Re: [Bitcoin-development] bitcoin pull requests

[Will]

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The threat of a SHA1 collision attack to insert a malicious pull request
are tiny compared with the other threats - e.g. github being compromised,
one of the core developers' passwords being compromised, one of the core
developers going rogue, sourceforge (distribution site) being compromised
etc etc... believe me there's a lot more to worry about than a SHA1
attack...

Not meaning to scare, just to put things in perspective - this is why we
all need to peer review each others commits and keep an eye out for
suspicious commits, leverage the benefits of this project being open source
and easily peer reviewed.

Will


On 1 April 2013 23:52, Melvin Carvalho <melvincarvalho@gmail.com> wrote:

>
>
>
> On 1 April 2013 20:28, Petr Praus <petr@praus.net> wrote:
>
>> An attacker would have to find a collision between two specific pieces of
>> code - his malicious code and a useful innoculous code that would be
>> accepted as pull request. This is the second, much harder case in the
>> birthday problem. When people talk about SHA-1 being broken they actually
>> mean the first case in the birthday problem - find any two arbitrary values
>> that hash to the same value. So, no I don't think it's a feasible attack
>> vector any time soon.
>>
>> Besides, with that kind of hashing power, it might be more feasible to
>> cause problems in the chain by e.g. constantly splitting it.
>>
>
> OK, maybe im being *way* too paranoid here ... but what if someone had
> access to github, could they replace one file with one they had prepared at
> some point?
>
>
>>
>>
>> On 1 April 2013 03:26, Melvin Carvalho <melvincarvalho@gmail.com> wrote:
>>
>>>  I was just looking at:
>>>
>>> https://bitcointalk.org/index.php?topic=4571.0
>>>
>>> I'm just curious if there is a possible attack vector here based on the
>>> fact that git uses the relatively week SHA1
>>>
>>> Could a seemingly innocuous pull request generate another file with a
>>> backdoor/nonce combination that slips under the radar?
>>>
>>> Apologies if this has come up before ...
>>>
>>>
>>> ------------------------------------------------------------------------------
>>> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
>>> Rise to greatness in Intel's independent game demo contest.
>>> Compete for recognition, cash, and the chance to get your game
>>> on Steam. $5K grand prize plus 10 genre and skill prizes.
>>> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
>>> _______________________________________________
>>> Bitcoin-development mailing list
>>> Bitcoin-development@lists.sourceforge.net
>>> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
>>>
>>>
>>
>
>
> ------------------------------------------------------------------------------
> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
> Rise to greatness in Intel's independent game demo contest.
> Compete for recognition, cash, and the chance to get your game
> on Steam. $5K grand prize plus 10 genre and skill prizes.
> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
> _______________________________________________
> Bitcoin-development mailing list
> Bitcoin-development@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
>
>

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Re: [Bitcoin-development] bitcoin pull requests

[Melvin Carvalho]

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On 2 April 2013 00:10, Will <will@phase.net> wrote:

> The threat of a SHA1 collision attack to insert a malicious pull request
> are tiny compared with the other threats - e.g. github being compromised,
> one of the core developers' passwords being compromised, one of the core
> developers going rogue, sourceforge (distribution site) being compromised
> etc etc... believe me there's a lot more to worry about than a SHA1
> attack...
>
> Not meaning to scare, just to put things in perspective - this is why we
> all need to peer review each others commits and keep an eye out for
> suspicious commits, leverage the benefits of this project being open source
> and easily peer reviewed.
>

Very good points, and I think you're absolutely right.

But just running the numbers, to get the picture, based of scheiner's
statistics:

http://www.schneier.com/blog/archives/2012/10/when_will_we_se.html

We're talking about a million terrahashes = 2^60 right?

With the block chain, you only have a 10 minute window, but with source
code you have a longer time to prepare.

Couldnt this be done with an ASIC in about a week?



>
> Will
>
>
> On 1 April 2013 23:52, Melvin Carvalho <melvincarvalho@gmail.com> wrote:
>
>>
>>
>>
>> On 1 April 2013 20:28, Petr Praus <petr@praus.net> wrote:
>>
>>> An attacker would have to find a collision between two specific pieces
>>> of code - his malicious code and a useful innoculous code that would be
>>> accepted as pull request. This is the second, much harder case in the
>>> birthday problem. When people talk about SHA-1 being broken they actually
>>> mean the first case in the birthday problem - find any two arbitrary values
>>> that hash to the same value. So, no I don't think it's a feasible attack
>>> vector any time soon.
>>>
>>> Besides, with that kind of hashing power, it might be more feasible to
>>> cause problems in the chain by e.g. constantly splitting it.
>>>
>>
>> OK, maybe im being *way* too paranoid here ... but what if someone had
>> access to github, could they replace one file with one they had prepared at
>> some point?
>>
>>
>>>
>>>
>>> On 1 April 2013 03:26, Melvin Carvalho <melvincarvalho@gmail.com> wrote:
>>>
>>>>  I was just looking at:
>>>>
>>>> https://bitcointalk.org/index.php?topic=4571.0
>>>>
>>>> I'm just curious if there is a possible attack vector here based on the
>>>> fact that git uses the relatively week SHA1
>>>>
>>>> Could a seemingly innocuous pull request generate another file with a
>>>> backdoor/nonce combination that slips under the radar?
>>>>
>>>> Apologies if this has come up before ...
>>>>
>>>>
>>>> ------------------------------------------------------------------------------
>>>> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
>>>> Rise to greatness in Intel's independent game demo contest.
>>>> Compete for recognition, cash, and the chance to get your game
>>>> on Steam. $5K grand prize plus 10 genre and skill prizes.
>>>> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
>>>> _______________________________________________
>>>> Bitcoin-development mailing list
>>>> Bitcoin-development@lists.sourceforge.net
>>>> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
>>>>
>>>>
>>>
>>
>>
>> ------------------------------------------------------------------------------
>> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
>> Rise to greatness in Intel's independent game demo contest.
>> Compete for recognition, cash, and the chance to get your game
>> on Steam. $5K grand prize plus 10 genre and skill prizes.
>> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
>> _______________________________________________
>> Bitcoin-development mailing list
>> Bitcoin-development@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
>>
>>
>

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Re: [Bitcoin-development] bitcoin pull requests

[Roy Badami]

The attack Schneier is talking about is a collision attack (i.e. it
creates two messages with the same hash, but you don't get to choose
either of the messages).  It's not a second preimage attack, which is
what you would need to be able to create a message that hashes to the
same value of an existing message.

(And it neither have anything to do with the birthday paradox, BTW -
which relates to the chance of eventually finding two messages that
hash to the same value by pure change)

If someone gets malicious code into the repo, it's going to be by
social engineering, not by breaking the cyrpto.

roy

On Tue, Apr 02, 2013 at 12:27:51AM +0200, Melvin Carvalho wrote:
> On 2 April 2013 00:10, Will <will@phase.net> wrote:
> 
> > The threat of a SHA1 collision attack to insert a malicious pull request
> > are tiny compared with the other threats - e.g. github being compromised,
> > one of the core developers' passwords being compromised, one of the core
> > developers going rogue, sourceforge (distribution site) being compromised
> > etc etc... believe me there's a lot more to worry about than a SHA1
> > attack...
> >
> > Not meaning to scare, just to put things in perspective - this is why we
> > all need to peer review each others commits and keep an eye out for
> > suspicious commits, leverage the benefits of this project being open source
> > and easily peer reviewed.
> >
> 
> Very good points, and I think you're absolutely right.
> 
> But just running the numbers, to get the picture, based of scheiner's
> statistics:
> 
> http://www.schneier.com/blog/archives/2012/10/when_will_we_se.html
> 
> We're talking about a million terrahashes = 2^60 right?
> 
> With the block chain, you only have a 10 minute window, but with source
> code you have a longer time to prepare.
> 
> Couldnt this be done with an ASIC in about a week?
> 
> 
> 
> >
> > Will
> >
> >
> > On 1 April 2013 23:52, Melvin Carvalho <melvincarvalho@gmail.com> wrote:
> >
> >>
> >>
> >>
> >> On 1 April 2013 20:28, Petr Praus <petr@praus.net> wrote:
> >>
> >>> An attacker would have to find a collision between two specific pieces
> >>> of code - his malicious code and a useful innoculous code that would be
> >>> accepted as pull request. This is the second, much harder case in the
> >>> birthday problem. When people talk about SHA-1 being broken they actually
> >>> mean the first case in the birthday problem - find any two arbitrary values
> >>> that hash to the same value. So, no I don't think it's a feasible attack
> >>> vector any time soon.
> >>>
> >>> Besides, with that kind of hashing power, it might be more feasible to
> >>> cause problems in the chain by e.g. constantly splitting it.
> >>>
> >>
> >> OK, maybe im being *way* too paranoid here ... but what if someone had
> >> access to github, could they replace one file with one they had prepared at
> >> some point?
> >>
> >>
> >>>
> >>>
> >>> On 1 April 2013 03:26, Melvin Carvalho <melvincarvalho@gmail.com> wrote:
> >>>
> >>>>  I was just looking at:
> >>>>
> >>>> https://bitcointalk.org/index.php?topic=4571.0
> >>>>
> >>>> I'm just curious if there is a possible attack vector here based on the
> >>>> fact that git uses the relatively week SHA1
> >>>>
> >>>> Could a seemingly innocuous pull request generate another file with a
> >>>> backdoor/nonce combination that slips under the radar?
> >>>>
> >>>> Apologies if this has come up before ...
> >>>>
> >>>>
> >>>> ------------------------------------------------------------------------------
> >>>> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
> >>>> Rise to greatness in Intel's independent game demo contest.
> >>>> Compete for recognition, cash, and the chance to get your game
> >>>> on Steam. $5K grand prize plus 10 genre and skill prizes.
> >>>> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
> >>>> _______________________________________________
> >>>> Bitcoin-development mailing list
> >>>> Bitcoin-development@lists.sourceforge.net
> >>>> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
> >>>>
> >>>>
> >>>
> >>
> >>
> >> ------------------------------------------------------------------------------
> >> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
> >> Rise to greatness in Intel's independent game demo contest.
> >> Compete for recognition, cash, and the chance to get your game
> >> on Steam. $5K grand prize plus 10 genre and skill prizes.
> >> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
> >> _______________________________________________
> >> Bitcoin-development mailing list
> >> Bitcoin-development@lists.sourceforge.net
> >> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
> >>
> >>
> >

> ------------------------------------------------------------------------------
> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
> Rise to greatness in Intel's independent game demo contest.
> Compete for recognition, cash, and the chance to get your game 
> on Steam. $5K grand prize plus 10 genre and skill prizes. 
> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d

> _______________________________________________
> Bitcoin-development mailing list
> Bitcoin-development@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/bitcoin-development

Re: [Bitcoin-development] bitcoin pull requests

[Roy Badami]

And the moment I hit send I realised it's not necessarily true.
Conceivably, a collision attack might help you craft two commits (one
good, one bad) with the same hash.

But I still maintain what I just posted is true: if someone gets
malicious code into the repo, it's going to be by social engineering,
not by breaking the cyrpto.

roy


On Mon, Apr 01, 2013 at 11:51:07PM +0100, Roy Badami wrote:
> The attack Schneier is talking about is a collision attack (i.e. it
> creates two messages with the same hash, but you don't get to choose
> either of the messages).  It's not a second preimage attack, which is
> what you would need to be able to create a message that hashes to the
> same value of an existing message.
> 
> (And it neither have anything to do with the birthday paradox, BTW -
> which relates to the chance of eventually finding two messages that
> hash to the same value by pure change)
> 
> If someone gets malicious code into the repo, it's going to be by
> social engineering, not by breaking the cyrpto.
> 
> roy
> 
> On Tue, Apr 02, 2013 at 12:27:51AM +0200, Melvin Carvalho wrote:
> > On 2 April 2013 00:10, Will <will@phase.net> wrote:
> > 
> > > The threat of a SHA1 collision attack to insert a malicious pull request
> > > are tiny compared with the other threats - e.g. github being compromised,
> > > one of the core developers' passwords being compromised, one of the core
> > > developers going rogue, sourceforge (distribution site) being compromised
> > > etc etc... believe me there's a lot more to worry about than a SHA1
> > > attack...
> > >
> > > Not meaning to scare, just to put things in perspective - this is why we
> > > all need to peer review each others commits and keep an eye out for
> > > suspicious commits, leverage the benefits of this project being open source
> > > and easily peer reviewed.
> > >
> > 
> > Very good points, and I think you're absolutely right.
> > 
> > But just running the numbers, to get the picture, based of scheiner's
> > statistics:
> > 
> > http://www.schneier.com/blog/archives/2012/10/when_will_we_se.html
> > 
> > We're talking about a million terrahashes = 2^60 right?
> > 
> > With the block chain, you only have a 10 minute window, but with source
> > code you have a longer time to prepare.
> > 
> > Couldnt this be done with an ASIC in about a week?
> > 
> > 
> > 
> > >
> > > Will
> > >
> > >
> > > On 1 April 2013 23:52, Melvin Carvalho <melvincarvalho@gmail.com> wrote:
> > >
> > >>
> > >>
> > >>
> > >> On 1 April 2013 20:28, Petr Praus <petr@praus.net> wrote:
> > >>
> > >>> An attacker would have to find a collision between two specific pieces
> > >>> of code - his malicious code and a useful innoculous code that would be
> > >>> accepted as pull request. This is the second, much harder case in the
> > >>> birthday problem. When people talk about SHA-1 being broken they actually
> > >>> mean the first case in the birthday problem - find any two arbitrary values
> > >>> that hash to the same value. So, no I don't think it's a feasible attack
> > >>> vector any time soon.
> > >>>
> > >>> Besides, with that kind of hashing power, it might be more feasible to
> > >>> cause problems in the chain by e.g. constantly splitting it.
> > >>>
> > >>
> > >> OK, maybe im being *way* too paranoid here ... but what if someone had
> > >> access to github, could they replace one file with one they had prepared at
> > >> some point?
> > >>
> > >>
> > >>>
> > >>>
> > >>> On 1 April 2013 03:26, Melvin Carvalho <melvincarvalho@gmail.com> wrote:
> > >>>
> > >>>>  I was just looking at:
> > >>>>
> > >>>> https://bitcointalk.org/index.php?topic=4571.0
> > >>>>
> > >>>> I'm just curious if there is a possible attack vector here based on the
> > >>>> fact that git uses the relatively week SHA1
> > >>>>
> > >>>> Could a seemingly innocuous pull request generate another file with a
> > >>>> backdoor/nonce combination that slips under the radar?
> > >>>>
> > >>>> Apologies if this has come up before ...
> > >>>>
> > >>>>
> > >>>> ------------------------------------------------------------------------------
> > >>>> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
> > >>>> Rise to greatness in Intel's independent game demo contest.
> > >>>> Compete for recognition, cash, and the chance to get your game
> > >>>> on Steam. $5K grand prize plus 10 genre and skill prizes.
> > >>>> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
> > >>>> _______________________________________________
> > >>>> Bitcoin-development mailing list
> > >>>> Bitcoin-development@lists.sourceforge.net
> > >>>> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
> > >>>>
> > >>>>
> > >>>
> > >>
> > >>
> > >> ------------------------------------------------------------------------------
> > >> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
> > >> Rise to greatness in Intel's independent game demo contest.
> > >> Compete for recognition, cash, and the chance to get your game
> > >> on Steam. $5K grand prize plus 10 genre and skill prizes.
> > >> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
> > >> _______________________________________________
> > >> Bitcoin-development mailing list
> > >> Bitcoin-development@lists.sourceforge.net
> > >> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
> > >>
> > >>
> > >
> 
> > ------------------------------------------------------------------------------
> > Own the Future-Intel&reg; Level Up Game Demo Contest 2013
> > Rise to greatness in Intel's independent game demo contest.
> > Compete for recognition, cash, and the chance to get your game 
> > on Steam. $5K grand prize plus 10 genre and skill prizes. 
> > Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
> 
> > _______________________________________________
> > Bitcoin-development mailing list
> > Bitcoin-development@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/bitcoin-development
> 
> 
> ------------------------------------------------------------------------------
> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
> Rise to greatness in Intel's independent game demo contest.
> Compete for recognition, cash, and the chance to get your game 
> on Steam. $5K grand prize plus 10 genre and skill prizes. 
> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
> _______________________________________________
> Bitcoin-development mailing list
> Bitcoin-development@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
> 

Re: [Bitcoin-development] bitcoin pull requests

[Wladimir]

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Maybe now that bitcoin is growing out of the toy phase it's an idea to
start gpg signing commits, like the Linux kernel (
https://lwn.net/Articles/466468/).

But I suppose then we can't use github anymore to merge as-is and need
manual steps?

Wladimir




On Tue, Apr 2, 2013 at 12:54 AM, Roy Badami <roy@gnomon.org.uk> wrote:

> And the moment I hit send I realised it's not necessarily true.
> Conceivably, a collision attack might help you craft two commits (one
> good, one bad) with the same hash.
>
> But I still maintain what I just posted is true: if someone gets
> malicious code into the repo, it's going to be by social engineering,
> not by breaking the cyrpto.
>
> roy
>
>
> On Mon, Apr 01, 2013 at 11:51:07PM +0100, Roy Badami wrote:
> > The attack Schneier is talking about is a collision attack (i.e. it
> > creates two messages with the same hash, but you don't get to choose
> > either of the messages).  It's not a second preimage attack, which is
> > what you would need to be able to create a message that hashes to the
> > same value of an existing message.
> >
> > (And it neither have anything to do with the birthday paradox, BTW -
> > which relates to the chance of eventually finding two messages that
> > hash to the same value by pure change)
> >
> > If someone gets malicious code into the repo, it's going to be by
> > social engineering, not by breaking the cyrpto.
> >
> > roy
> >
> > On Tue, Apr 02, 2013 at 12:27:51AM +0200, Melvin Carvalho wrote:
> > > On 2 April 2013 00:10, Will <will@phase.net> wrote:
> > >
> > > > The threat of a SHA1 collision attack to insert a malicious pull
> request
> > > > are tiny compared with the other threats - e.g. github being
> compromised,
> > > > one of the core developers' passwords being compromised, one of the
> core
> > > > developers going rogue, sourceforge (distribution site) being
> compromised
> > > > etc etc... believe me there's a lot more to worry about than a SHA1
> > > > attack...
> > > >
> > > > Not meaning to scare, just to put things in perspective - this is
> why we
> > > > all need to peer review each others commits and keep an eye out for
> > > > suspicious commits, leverage the benefits of this project being open
> source
> > > > and easily peer reviewed.
> > > >
> > >
> > > Very good points, and I think you're absolutely right.
> > >
> > > But just running the numbers, to get the picture, based of scheiner's
> > > statistics:
> > >
> > > http://www.schneier.com/blog/archives/2012/10/when_will_we_se.html
> > >
> > > We're talking about a million terrahashes = 2^60 right?
> > >
> > > With the block chain, you only have a 10 minute window, but with source
> > > code you have a longer time to prepare.
> > >
> > > Couldnt this be done with an ASIC in about a week?
> > >
> > >
> > >
> > > >
> > > > Will
> > > >
> > > >
> > > > On 1 April 2013 23:52, Melvin Carvalho <melvincarvalho@gmail.com>
> wrote:
> > > >
> > > >>
> > > >>
> > > >>
> > > >> On 1 April 2013 20:28, Petr Praus <petr@praus.net> wrote:
> > > >>
> > > >>> An attacker would have to find a collision between two specific
> pieces
> > > >>> of code - his malicious code and a useful innoculous code that
> would be
> > > >>> accepted as pull request. This is the second, much harder case in
> the
> > > >>> birthday problem. When people talk about SHA-1 being broken they
> actually
> > > >>> mean the first case in the birthday problem - find any two
> arbitrary values
> > > >>> that hash to the same value. So, no I don't think it's a feasible
> attack
> > > >>> vector any time soon.
> > > >>>
> > > >>> Besides, with that kind of hashing power, it might be more
> feasible to
> > > >>> cause problems in the chain by e.g. constantly splitting it.
> > > >>>
> > > >>
> > > >> OK, maybe im being *way* too paranoid here ... but what if someone
> had
> > > >> access to github, could they replace one file with one they had
> prepared at
> > > >> some point?
> > > >>
> > > >>
> > > >>>
> > > >>>
> > > >>> On 1 April 2013 03:26, Melvin Carvalho <melvincarvalho@gmail.com>
> wrote:
> > > >>>
> > > >>>>  I was just looking at:
> > > >>>>
> > > >>>> https://bitcointalk.org/index.php?topic=4571.0
> > > >>>>
> > > >>>> I'm just curious if there is a possible attack vector here based
> on the
> > > >>>> fact that git uses the relatively week SHA1
> > > >>>>
> > > >>>> Could a seemingly innocuous pull request generate another file
> with a
> > > >>>> backdoor/nonce combination that slips under the radar?
> > > >>>>
> > > >>>> Apologies if this has come up before ...
> > > >>>>
> > > >>>>
> > > >>>>
> ------------------------------------------------------------------------------
> > > >>>> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
> > > >>>> Rise to greatness in Intel's independent game demo contest.
> > > >>>> Compete for recognition, cash, and the chance to get your game
> > > >>>> on Steam. $5K grand prize plus 10 genre and skill prizes.
> > > >>>> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
> > > >>>> _______________________________________________
> > > >>>> Bitcoin-development mailing list
> > > >>>> Bitcoin-development@lists.sourceforge.net
> > > >>>> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
> > > >>>>
> > > >>>>
> > > >>>
> > > >>
> > > >>
> > > >>
> ------------------------------------------------------------------------------
> > > >> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
> > > >> Rise to greatness in Intel's independent game demo contest.
> > > >> Compete for recognition, cash, and the chance to get your game
> > > >> on Steam. $5K grand prize plus 10 genre and skill prizes.
> > > >> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
> > > >> _______________________________________________
> > > >> Bitcoin-development mailing list
> > > >> Bitcoin-development@lists.sourceforge.net
> > > >> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
> > > >>
> > > >>
> > > >
> >
> > >
> ------------------------------------------------------------------------------
> > > Own the Future-Intel&reg; Level Up Game Demo Contest 2013
> > > Rise to greatness in Intel's independent game demo contest.
> > > Compete for recognition, cash, and the chance to get your game
> > > on Steam. $5K grand prize plus 10 genre and skill prizes.
> > > Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
> >
> > > _______________________________________________
> > > Bitcoin-development mailing list
> > > Bitcoin-development@lists.sourceforge.net
> > > https://lists.sourceforge.net/lists/listinfo/bitcoin-development
> >
> >
> >
> ------------------------------------------------------------------------------
> > Own the Future-Intel&reg; Level Up Game Demo Contest 2013
> > Rise to greatness in Intel's independent game demo contest.
> > Compete for recognition, cash, and the chance to get your game
> > on Steam. $5K grand prize plus 10 genre and skill prizes.
> > Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
> > _______________________________________________
> > Bitcoin-development mailing list
> > Bitcoin-development@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/bitcoin-development
> >
>
>
> ------------------------------------------------------------------------------
> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
> Rise to greatness in Intel's independent game demo contest.
> Compete for recognition, cash, and the chance to get your game
> on Steam. $5K grand prize plus 10 genre and skill prizes.
> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
> _______________________________________________
> Bitcoin-development mailing list
> Bitcoin-development@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
>

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Re: [Bitcoin-development] bitcoin pull requests

[Jeff Garzik]

On Tue, Apr 2, 2013 at 11:41 PM, Wladimir <laanwj@gmail.com> wrote:
> Maybe now that bitcoin is growing out of the toy phase it's an idea to start
> gpg signing commits, like the Linux kernel
> (https://lwn.net/Articles/466468/).
>
> But I suppose then we can't use github anymore to merge as-is and need
> manual steps?

Correct, that rules out github, AFAICS.

Though, honestly, when I ACK that means I read the code, which is more
important than the author really.  github seems fine for that still,
though I do wonder if there is a race possible,

* sneak uploads innocent branch sneak/bitcoin.git #innocent
* sneak creates pull req
* just before I click "pull", sneak rebases the branch to something evil

-- 
Jeff Garzik
exMULTI, Inc.
jgarzik@exmulti.com

Re: [Bitcoin-development] bitcoin pull requests

[grarpamp]

>> gpg signing commits, like the Linux kernel

> Though, honestly, when I ACK that means I read the code, which is more
> important than the author really.  github seems fine for that still,
> though I do wonder if there is a race possible,
>
> * just before I click "pull", sneak rebases the branch to something evil


You might want to look at http://www.monotone.ca/, it does a good job
of integrating crypto and review primitives into the workflow.
It also has some reliable network distribution models (netsync) that work
well over things like Tor, in case a new developer (or old Satoshi) doesn't
wish to be in the public light.

http://www.monotone.ca/monotone.html

Once you have the crypto, it always boils down to human risk factors,
rogue, password, cracks, etc which are harder.

Re: [Bitcoin-development] bitcoin pull requests

[Gavin Andresen]

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I would rather we spend time working to make users' bitcoins safe EVEN IF
their bitcoin software is compromised.

Eliminate the "if you get a bad bitcoin-qt.exe somehow you're in big
trouble" risk entirely, instead of worrying about unlikely scenarios like a
timing attack in between ACKs/pulls. Eliminate one piece of software as the
possible single point of failure...

-- 
--
Gavin Andresen

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Re: [Bitcoin-development] bitcoin pull requests

[grarpamp]

> Eliminate the "if you get a bad bitcoin-qt.exe somehow you're in big
> trouble" risk entirely

This isn't really possible. A trojaned client will spend your coin as
easily as the owner can, passphrases will be logged, windows box will
be owned, secondary remote spendauth sigs into the network chain
break similarly, securely hashcheck the trojaned client from cracked
userspace on a hacked dll/kernel with uefi backdoor and a trojaned
hasher, etc.

It's easier for a few developers to meet in person to init and sig
a new repo than to try fixing the world's userland and users :)
At least that way you get something verifiable back to the root.

Re: [Bitcoin-development] bitcoin pull requests

[grarpamp]

> Users will have available multisig addresses which require
> transactions to be signed off by a wallet HSM. (E.g. a keyfob

Hardware is a good thing. But only if you do the crypto in the
hardware and trust the hardware and its attack models ;) For
instance, the fingerprint readers you see everywhere... many
of them just present the raw fingerprint scan to the host (and
host software), instead of hashing the fingerprint internally and
using that as primitive in crypto exchanges with the host. They
cheaped out and/or didn't think. So oops, there went both your
security (host replay) and your personal privacy (biometrics),
outside of your control. All with no protection against physical
fingerprint lifting.

> This doesn't remove the need to improve repository integrity. ... but
> repository integrity is a general problem that is applicable to many
> things (after all, what does it matter if you can't compromise Bitcoin
> if you can compromise boost, openssl, or gcc?)

Yes, that case would matter zero to the end product. However
having a strong repo permits better auditing of the BTC codebase.
That's a good thing, and eliminates the need to talk chicken and
egg.

> It's probably best
> that Bitcoin specalists stay focused on Bitcoin security measures, and
> other people interested in repository security come and help out
> improving it.  An obvious area of improvement might be oddity
> detection and alerting:  It's weird that I can rewrite history on
> github, so long as I do it quickly, without anyone noticing.

If no one is verifying the repo, sure, even entire repos could be
swapped out for seemingly identical ones.

Many repos do not have any strong internal verification structures
at all, and they run on filesystems that accept bitrot.
Take a look at some OS's... OpenBSD and FreeBSD, supposedly
the more secure ones out there... both use legacy repos on FFS.
Seems rather ironic in the lol department.

Thankfully some people out there are finally getting a clue on these
issues, making and learning the tools, converting and migrating
things, working on top down signed build and distribution chain, etc...
so maybe in ten years the opensource world will be much farther
ahead. Or at least have a strong audit trail.

Re: [Bitcoin-development] bitcoin pull requests

[Mike Hearn]

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My general hope/vague plan for bitcoinj based wallets is to get them all on
to automatic updates with threshold signatures. Combined with regular
audits of the initial downloads for new users, that should give a pretty
safe result that is immune to a developer going rogue.


On Wed, Apr 3, 2013 at 7:12 PM, grarpamp <grarpamp@gmail.com> wrote:

> > Users will have available multisig addresses which require
> > transactions to be signed off by a wallet HSM. (E.g. a keyfob
>
> Hardware is a good thing. But only if you do the crypto in the
> hardware and trust the hardware and its attack models ;) For
> instance, the fingerprint readers you see everywhere... many
> of them just present the raw fingerprint scan to the host (and
> host software), instead of hashing the fingerprint internally and
> using that as primitive in crypto exchanges with the host. They
> cheaped out and/or didn't think. So oops, there went both your
> security (host replay) and your personal privacy (biometrics),
> outside of your control. All with no protection against physical
> fingerprint lifting.
>
> > This doesn't remove the need to improve repository integrity. ... but
> > repository integrity is a general problem that is applicable to many
> > things (after all, what does it matter if you can't compromise Bitcoin
> > if you can compromise boost, openssl, or gcc?)
>
> Yes, that case would matter zero to the end product. However
> having a strong repo permits better auditing of the BTC codebase.
> That's a good thing, and eliminates the need to talk chicken and
> egg.
>
> > It's probably best
> > that Bitcoin specalists stay focused on Bitcoin security measures, and
> > other people interested in repository security come and help out
> > improving it.  An obvious area of improvement might be oddity
> > detection and alerting:  It's weird that I can rewrite history on
> > github, so long as I do it quickly, without anyone noticing.
>
> If no one is verifying the repo, sure, even entire repos could be
> swapped out for seemingly identical ones.
>
> Many repos do not have any strong internal verification structures
> at all, and they run on filesystems that accept bitrot.
> Take a look at some OS's... OpenBSD and FreeBSD, supposedly
> the more secure ones out there... both use legacy repos on FFS.
> Seems rather ironic in the lol department.
>
> Thankfully some people out there are finally getting a clue on these
> issues, making and learning the tools, converting and migrating
> things, working on top down signed build and distribution chain, etc...
> so maybe in ten years the opensource world will be much farther
> ahead. Or at least have a strong audit trail.
>
>
> ------------------------------------------------------------------------------
> Minimize network downtime and maximize team effectiveness.
> Reduce network management and security costs.Learn how to hire
> the most talented Cisco Certified professionals. Visit the
> Employer Resources Portal
> http://www.cisco.com/web/learning/employer_resources/index.html
> _______________________________________________
> Bitcoin-development mailing list
> Bitcoin-development@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
>

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Re: [Bitcoin-development] bitcoin pull requests

[Mike Hearn]

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By the way, I have a download of the Bitcoin-Qt client and signature
verification running in a cron job.


On Thu, Apr 4, 2013 at 10:11 AM, Mike Hearn <mike@plan99.net> wrote:

> My general hope/vague plan for bitcoinj based wallets is to get them all
> on to automatic updates with threshold signatures. Combined with regular
> audits of the initial downloads for new users, that should give a pretty
> safe result that is immune to a developer going rogue.
>
>
> On Wed, Apr 3, 2013 at 7:12 PM, grarpamp <grarpamp@gmail.com> wrote:
>
>> > Users will have available multisig addresses which require
>> > transactions to be signed off by a wallet HSM. (E.g. a keyfob
>>
>> Hardware is a good thing. But only if you do the crypto in the
>> hardware and trust the hardware and its attack models ;) For
>> instance, the fingerprint readers you see everywhere... many
>> of them just present the raw fingerprint scan to the host (and
>> host software), instead of hashing the fingerprint internally and
>> using that as primitive in crypto exchanges with the host. They
>> cheaped out and/or didn't think. So oops, there went both your
>> security (host replay) and your personal privacy (biometrics),
>> outside of your control. All with no protection against physical
>> fingerprint lifting.
>>
>> > This doesn't remove the need to improve repository integrity. ... but
>> > repository integrity is a general problem that is applicable to many
>> > things (after all, what does it matter if you can't compromise Bitcoin
>> > if you can compromise boost, openssl, or gcc?)
>>
>> Yes, that case would matter zero to the end product. However
>> having a strong repo permits better auditing of the BTC codebase.
>> That's a good thing, and eliminates the need to talk chicken and
>> egg.
>>
>> > It's probably best
>> > that Bitcoin specalists stay focused on Bitcoin security measures, and
>> > other people interested in repository security come and help out
>> > improving it.  An obvious area of improvement might be oddity
>> > detection and alerting:  It's weird that I can rewrite history on
>> > github, so long as I do it quickly, without anyone noticing.
>>
>> If no one is verifying the repo, sure, even entire repos could be
>> swapped out for seemingly identical ones.
>>
>> Many repos do not have any strong internal verification structures
>> at all, and they run on filesystems that accept bitrot.
>> Take a look at some OS's... OpenBSD and FreeBSD, supposedly
>> the more secure ones out there... both use legacy repos on FFS.
>> Seems rather ironic in the lol department.
>>
>> Thankfully some people out there are finally getting a clue on these
>> issues, making and learning the tools, converting and migrating
>> things, working on top down signed build and distribution chain, etc...
>> so maybe in ten years the opensource world will be much farther
>> ahead. Or at least have a strong audit trail.
>>
>>
>> ------------------------------------------------------------------------------
>> Minimize network downtime and maximize team effectiveness.
>> Reduce network management and security costs.Learn how to hire
>> the most talented Cisco Certified professionals. Visit the
>> Employer Resources Portal
>> http://www.cisco.com/web/learning/employer_resources/index.html
>> _______________________________________________
>> Bitcoin-development mailing list
>> Bitcoin-development@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
>>
>
>

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