Re: [Bitcoin-development] Missing fRelayTxes in version message
I never said that Bitcoin message field lengths should always be the same. But
before this change they certainly were constant per protocol version. All I'm
saying is that optional lengths shouldn't be used (a field exists or not) and
for every field change, the protocol version should be upgraded.
Now that fRelayTxes is part of the protocol, the version number should be
upgraded to reflect this fact.
From: Mike Hearn m...@plan99.net
To: Paul Lyon pml...@hotmail.ca
Cc: Turkey Breast turkeybre...@yahoo.com;
bitcoin-development@lists.sourceforge.net
bitcoin-development@lists.sourceforge.net
Sent: Wednesday, June 19, 2013 3:20 PM
Subject: Re: [Bitcoin-development] Missing fRelayTxes in version message
If you want to criticise the Bitcoin protocol for sloppyness, the variable
length of some messages isn't where I'd start.
Note that ping has the same issue, its length has changed over time to include
the nonce.
If your parser can't handle that kind of thing, you need to fix it. The
protocol has always worked that way.
On Wed, Jun 19, 2013 at 3:03 PM, Paul Lyon pml...@hotmail.ca wrote:
I’m also running into this exact same issue with my parser, now I understand
why the relay field behavior I was seeing doesn’t match the wiki.
So to parse a version message, you can’t rely on the protocol version? You
have to know how long the payload is, and then parse the message accordingly?
I agree with Turkey Breast, this seems a bit sloppy to me.
Paul
P.S. I’ve never used a dev mailing list before and I want to get involved with
the Bitcoin dev community, so let me know if I’m horribly violating any
mailing list etiquette.
From: Mike Hearn
Sent: Wednesday, June 19, 2013 7:43 AM
To: Turkey Breast
Cc: bitcoin-development@lists.sourceforge.net
Bitcoin-Qt on master does send it now although it doesn't affect anything, but
as old pre-filtering versions will continue to exist, you'll always have to be
able to deserialize version messages without it.
Bitcoin version messages have always had variable length, look at how the code
is written in main.cpp. If you didn't experience issues until now all it means
is that no sufficiently old nodes were talking to yours.
The standard does not say it should appear. Read it again - BIP 37 says about
the new version message field:
If false then broadcast transactions will not be announced until a
filter{load,add,clear} command is received. If missing or true, no change in
protocol behaviour occurs.
On Wed, Jun 19, 2013 at 12:33 PM, Turkey Breast turkeybre...@yahoo.com wrote:
It's a problem if you work with iterators to deserialize the byte stream. Even
failing that, it's just sloppy programming. What happens in the future when
new fields are added to the version message? It's not a big deal to say that
this protocol version has X number of fields, that (higher) protocol version
message has X + N number of fields. Deterministic number of fields per
protocol version is sensical and how Bitcoin has been for a long time.
And yes, it was a problem for me that caused a lot of confusion why this byte
didn't exist in many version messages despite the standard saying it should
and the code in bitcoind indicating it should. Nowhere was this written. It
doesn't help other implementations to have an unclear behaviour that depends
on some magic from one implementation.
From: Mike Hearn m...@plan99.net
To: Turkey Breast turkeybre...@yahoo.com
Cc: bitcoin-development@lists.sourceforge.net
bitcoin-development@lists.sourceforge.net
Sent: Wednesday, June 19, 2013 11:39 AM
Subject: Re: [Bitcoin-development] Missing fRelayTxes in version message
It has to be optional because old clients don't send it, obviously.
Why is this even an issue? There's no problem with variable length messages
in any codebase that I'm aware of. Is this solving some actual problem?
On Wed, Jun 19, 2013 at 12:30 AM, Turkey Breast turkeybre...@yahoo.com
wrote:
That's me. I never said to make all messages fixed length. I said to make a
fixed number of fields per protocol. So given a protocol version number, you
know the number of fields in a message. This is not only easier for parsing
messages, but just good practice. I don't see why a 1 byte flag needs to be
optional anyway.
From: Mike Hearn m...@plan99.net
To: Turkey Breast turkeybre...@yahoo.com
Cc: Bitcoin Dev bitcoin-development@lists.sourceforge.net
Sent: Tuesday, June 18, 2013 9:48 PM
Subject: Re: [Bitcoin-development] Missing fRelayTxes in version message
It's not a bug (although there was recently a change to make bitcoind/qt
always send this field anyway).
I don't know where Amir is going with BIP 60. Version messages have always
been variable length. There's nothing inherent in the Bitcoin protocol that
says all messages are fixed length, indeed, tx messages
Re: [Bitcoin-development] Missing fRelayTxes in version message
The protocol version was bumped when Bloom filtering was added so there's
not much point bumping it again - you have to handle the old clients no
matter what. Nobody brought this up as an issue when the BIP or code was
first written and as you can see from main.cpp, it was done this way to be
consistent with how other version fields are handled:
if (!vRecv.empty())
vRecv addrFrom nNonce;
if (!vRecv.empty())
vRecv pfrom-strSubVer;
if (!vRecv.empty())
vRecv pfrom-nStartingHeight;
if (!vRecv.empty())
vRecv pfrom-fRelayTxes; // set to true after we get the
first filter* message
The existence of the nStartingHeight field for instance depends on the
message length and not anything else.
Anyway, are you really asking for the protocol to be changed to work around
an issue specific to how you wrote your parsing code? This is the first
time anyone has suggested this minor detail is a problem. It doesn't
present any issues for the C++ code or bitcoinj where message objects know
their own length at parse time.
On Thu, Jun 20, 2013 at 8:20 AM, Turkey Breast turkeybre...@yahoo.comwrote:
I never said that Bitcoin message field lengths should always be the same.
But before this change they certainly were constant per protocol version.
All I'm saying is that optional lengths shouldn't be used (a field exists
or not) and for every field change, the protocol version should be upgraded.
Now that fRelayTxes is part of the protocol, the version number should be
upgraded to reflect this fact.
--
*From:* Mike Hearn m...@plan99.net
*To:* Paul Lyon pml...@hotmail.ca
*Cc:* Turkey Breast turkeybre...@yahoo.com;
bitcoin-development@lists.sourceforge.net
bitcoin-development@lists.sourceforge.net
*Sent:* Wednesday, June 19, 2013 3:20 PM
*Subject:* Re: [Bitcoin-development] Missing fRelayTxes in version message
If you want to criticise the Bitcoin protocol for sloppyness, the variable
length of some messages isn't where I'd start.
Note that ping has the same issue, its length has changed over time to
include the nonce.
If your parser can't handle that kind of thing, you need to fix it. The
protocol has always worked that way.
On Wed, Jun 19, 2013 at 3:03 PM, Paul Lyon pml...@hotmail.ca wrote:
I’m also running into this exact same issue with my parser, now I
understand why the relay field behavior I was seeing doesn’t match the wiki.
So to parse a version message, you can’t rely on the protocol version? You
have to know how long the payload is, and then parse the message
accordingly? I agree with Turkey Breast, this seems a bit sloppy to me.
Paul
P.S. I’ve never used a dev mailing list before and I want to get involved
with the Bitcoin dev community, so let me know if I’m horribly violating
any mailing list etiquette.
*From:* Mike Hearn
*Sent:* Wednesday, June 19, 2013 7:43 AM
*To:* Turkey Breast
*Cc:* bitcoin-development@lists.sourceforge.net
Bitcoin-Qt on master does send it now although it doesn't affect anything,
but as old pre-filtering versions will continue to exist, you'll always
have to be able to deserialize version messages without it.
Bitcoin version messages have always had variable length, look at how the
code is written in main.cpp. If you didn't experience issues until now all
it means is that no sufficiently old nodes were talking to yours.
The standard does not say it should appear. Read it again - BIP 37 says
about the new version message field:
If false then broadcast transactions will not be announced until a
filter{load,add,clear} command is received. *If missing or true*, no
change in protocol behaviour occurs.
On Wed, Jun 19, 2013 at 12:33 PM, Turkey Breast turkeybre...@yahoo.comwrote:
It's a problem if you work with iterators to deserialize the byte stream.
Even failing that, it's just sloppy programming. What happens in the future
when new fields are added to the version message? It's not a big deal to
say that this protocol version has X number of fields, that (higher)
protocol version message has X + N number of fields. Deterministic number
of fields per protocol version is sensical and how Bitcoin has been for a
long time.
And yes, it was a problem for me that caused a lot of confusion why this
byte didn't exist in many version messages despite the standard saying it
should and the code in bitcoind indicating it should. Nowhere was this
written. It doesn't help other implementations to have an unclear behaviour
that depends on some magic from one implementation.
--
*From:* Mike Hearn m...@plan99.net
*To:* Turkey Breast turkeybre...@yahoo.com
*Cc:* bitcoin-development@lists.sourceforge.net
bitcoin-development@lists.sourceforge.net
*Sent:* Wednesday, June 19, 2013 11:39 AM
*Subject:* Re: [Bitcoin-development] Missing fRelayTxes in version message
It has
Re: [Bitcoin-development] Missing fRelayTxes in version message
I personally don't treat the relay field as optional, i.e. it is there as
0x01 if it is set. Otherwise, it is simply a trailing zero byte. Hence, the
right way of reading the packet as with any network packet is to first
retrieve the header information, get the actual payload length, then parse
the payload accordingly. I can also choose to include 0x00 for my relay
field in my outgoing packet and reflect that accordingly in my length field
in the header.
On Thu, Jun 20, 2013 at 4:20 PM, Turkey Breast turkeybre...@yahoo.comwrote:
I never said that Bitcoin message field lengths should always be the same.
But before this change they certainly were constant per protocol version.
All I'm saying is that optional lengths shouldn't be used (a field exists
or not) and for every field change, the protocol version should be upgraded.
Now that fRelayTxes is part of the protocol, the version number should be
upgraded to reflect this fact.
--
*From:* Mike Hearn m...@plan99.net
*To:* Paul Lyon pml...@hotmail.ca
*Cc:* Turkey Breast turkeybre...@yahoo.com;
bitcoin-development@lists.sourceforge.net
bitcoin-development@lists.sourceforge.net
*Sent:* Wednesday, June 19, 2013 3:20 PM
*Subject:* Re: [Bitcoin-development] Missing fRelayTxes in version message
If you want to criticise the Bitcoin protocol for sloppyness, the variable
length of some messages isn't where I'd start.
Note that ping has the same issue, its length has changed over time to
include the nonce.
If your parser can't handle that kind of thing, you need to fix it. The
protocol has always worked that way.
On Wed, Jun 19, 2013 at 3:03 PM, Paul Lyon pml...@hotmail.ca wrote:
I’m also running into this exact same issue with my parser, now I
understand why the relay field behavior I was seeing doesn’t match the wiki.
So to parse a version message, you can’t rely on the protocol version? You
have to know how long the payload is, and then parse the message
accordingly? I agree with Turkey Breast, this seems a bit sloppy to me.
Paul
P.S. I’ve never used a dev mailing list before and I want to get involved
with the Bitcoin dev community, so let me know if I’m horribly violating
any mailing list etiquette.
*From:* Mike Hearn
*Sent:* Wednesday, June 19, 2013 7:43 AM
*To:* Turkey Breast
*Cc:* bitcoin-development@lists.sourceforge.net
Bitcoin-Qt on master does send it now although it doesn't affect anything,
but as old pre-filtering versions will continue to exist, you'll always
have to be able to deserialize version messages without it.
Bitcoin version messages have always had variable length, look at how the
code is written in main.cpp. If you didn't experience issues until now all
it means is that no sufficiently old nodes were talking to yours.
The standard does not say it should appear. Read it again - BIP 37 says
about the new version message field:
If false then broadcast transactions will not be announced until a
filter{load,add,clear} command is received. *If missing or true*, no
change in protocol behaviour occurs.
On Wed, Jun 19, 2013 at 12:33 PM, Turkey Breast turkeybre...@yahoo.comwrote:
It's a problem if you work with iterators to deserialize the byte stream.
Even failing that, it's just sloppy programming. What happens in the future
when new fields are added to the version message? It's not a big deal to
say that this protocol version has X number of fields, that (higher)
protocol version message has X + N number of fields. Deterministic number
of fields per protocol version is sensical and how Bitcoin has been for a
long time.
And yes, it was a problem for me that caused a lot of confusion why this
byte didn't exist in many version messages despite the standard saying it
should and the code in bitcoind indicating it should. Nowhere was this
written. It doesn't help other implementations to have an unclear behaviour
that depends on some magic from one implementation.
--
*From:* Mike Hearn m...@plan99.net
*To:* Turkey Breast turkeybre...@yahoo.com
*Cc:* bitcoin-development@lists.sourceforge.net
bitcoin-development@lists.sourceforge.net
*Sent:* Wednesday, June 19, 2013 11:39 AM
*Subject:* Re: [Bitcoin-development] Missing fRelayTxes in version message
It has to be optional because old clients don't send it, obviously.
Why is this even an issue? There's no problem with variable length
messages in any codebase that I'm aware of. Is this solving some actual
problem?
On Wed, Jun 19, 2013 at 12:30 AM, Turkey Breast turkeybre...@yahoo.comwrote:
That's me. I never said to make all messages fixed length. I said to make
a fixed number of fields per protocol. So given a protocol version number,
you know the number of fields in a message. This is not only easier for
parsing messages, but just good practice. I don't see why a 1 byte flag
needs to be optional anyway.
Re: [Bitcoin-development] Missing fRelayTxes in version
Hi Mike, The issue with the current parser is that those fields are conditionally optional on that there will be no subsequent fields added. If there will be further fields they will become manadory. Why not bump the version and parse the fields as mandatory from then on? This would be backward compatible and cleaner going forward. Tamas Blummer http://bitsofproof.com -- This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Missing fRelayTxes in version
Sure but why not do that when there's an actual new field to add? Does anyone have a proposal for a feature that needs a new version field at the moment? There's no point changing the protocol now unless there's actually a new field to add. Anyway I still don't see why anyone cares about this issue. The Bitcoin protocol does not and never has required that all messages have a fixed number of fields per version. Any parser written on the assumption it did was just buggy. Look at how tx messages are relayed for the most obvious example of that pattern in action - it's actually the raw byte stream that's stored and relayed to ensure that fields added in new versions aren't dropped during round-tripping. Old versions are supposed to preserve fields from the future. On Thu, Jun 20, 2013 at 9:30 AM, Tamas Blummer ta...@bitsofproof.comwrote: Hi Mike, The issue with the current parser is that those fields are conditionally optional on that there will be no subsequent fields added. If there will be further fields they will become manadory. Why not bump the version and parse the fields as mandatory from then on? This would be backward compatible and cleaner going forward. Tamas Blummer http://bitsofproof.com http://bitsofproof.com/ -- This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development -- This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Missing fRelayTxes in version
I agree that this can be deferred until there is an actual new field without any harm. But then remember to update the BIP37 too saying that it is optional only if flag added in BIPXX is not present. Your argument is that this complexity is already there so why not preserve it. I think eliminating complexity (that has no benefit) strengthens the system. Tamás Blummer http://bitsofproof.com On 20.06.2013, at 09:36, Mike Hearn m...@plan99.net wrote: Sure but why not do that when there's an actual new field to add? Does anyone have a proposal for a feature that needs a new version field at the moment? There's no point changing the protocol now unless there's actually a new field to add. Anyway I still don't see why anyone cares about this issue. The Bitcoin protocol does not and never has required that all messages have a fixed number of fields per version. Any parser written on the assumption it did was just buggy. Look at how tx messages are relayed for the most obvious example of that pattern in action - it's actually the raw byte stream that's stored and relayed to ensure that fields added in new versions aren't dropped during round-tripping. Old versions are supposed to preserve fields from the future. On Thu, Jun 20, 2013 at 9:30 AM, Tamas Blummer ta...@bitsofproof.com wrote: Hi Mike, The issue with the current parser is that those fields are conditionally optional on that there will be no subsequent fields added. If there will be further fields they will become manadory. Why not bump the version and parse the fields as mandatory from then on? This would be backward compatible and cleaner going forward. Tamas Blummer http://bitsofproof.com -- This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development -- This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Missing fRelayTxes in version
You can't eliminate the complexity (yet), otherwise you wouldn't be able to talk to old nodes. You'll have to wait until versions prior to a particular version are hard-forked off and can be safely dropped at connect time. That said the reason I'm being so grumpy about this is that compared to the complexity in the rest of the system, this is such a trivial and minor detail. It's hardly even worth thinking about. I mean, we have a scripting language full of opcodes nobody ever figured out how to use and the protocol uses a mixture of byte orders, so an optional field in the version message is really not such a big deal :) On Thu, Jun 20, 2013 at 10:17 AM, Tamas Blummer ta...@bitsofproof.comwrote: I agree that this can be deferred until there is an actual new field without any harm. But then remember to update the BIP37 too saying that it is optional only if flag added in BIPXX is not present. Your argument is that this complexity is already there so why not preserve it. I think eliminating complexity (that has no benefit) strengthens the system. *Tamás Blummer* http://bitsofproof.com http://bitsofproof.com/ On 20.06.2013, at 09:36, Mike Hearn m...@plan99.net wrote: Sure but why not do that when there's an actual new field to add? Does anyone have a proposal for a feature that needs a new version field at the moment? There's no point changing the protocol now unless there's actually a new field to add. Anyway I still don't see why anyone cares about this issue. The Bitcoin protocol does not and never has required that all messages have a fixed number of fields per version. Any parser written on the assumption it did was just buggy. Look at how tx messages are relayed for the most obvious example of that pattern in action - it's actually the raw byte stream that's stored and relayed to ensure that fields added in new versions aren't dropped during round-tripping. Old versions are supposed to preserve fields from the future. On Thu, Jun 20, 2013 at 9:30 AM, Tamas Blummer ta...@bitsofproof.comwrote: Hi Mike, The issue with the current parser is that those fields are conditionally optional on that there will be no subsequent fields added. If there will be further fields they will become manadory. Why not bump the version and parse the fields as mandatory from then on? This would be backward compatible and cleaner going forward. Tamas Blummer http://bitsofproof.com http://bitsofproof.com/ -- This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development -- This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Missing fRelayTxes in version
Yes it is trivial. I do not think greater complexity in the system should keep us from addressing low complexity issues. You can't blame me or others not trying to simplify scripts, if there is such a headwind simplifying a version message. You are right there is too much fuss about this. Tamás Blummer Founder, CEO http://bitsofproof.com On 20.06.2013, at 10:31, Mike Hearn m...@plan99.net wrote: You can't eliminate the complexity (yet), otherwise you wouldn't be able to talk to old nodes. You'll have to wait until versions prior to a particular version are hard-forked off and can be safely dropped at connect time. That said the reason I'm being so grumpy about this is that compared to the complexity in the rest of the system, this is such a trivial and minor detail. It's hardly even worth thinking about. I mean, we have a scripting language full of opcodes nobody ever figured out how to use and the protocol uses a mixture of byte orders, so an optional field in the version message is really not such a big deal :) On Thu, Jun 20, 2013 at 10:17 AM, Tamas Blummer ta...@bitsofproof.com wrote: I agree that this can be deferred until there is an actual new field without any harm. But then remember to update the BIP37 too saying that it is optional only if flag added in BIPXX is not present. Your argument is that this complexity is already there so why not preserve it. I think eliminating complexity (that has no benefit) strengthens the system. Tamás Blummer http://bitsofproof.com On 20.06.2013, at 09:36, Mike Hearn m...@plan99.net wrote: Sure but why not do that when there's an actual new field to add? Does anyone have a proposal for a feature that needs a new version field at the moment? There's no point changing the protocol now unless there's actually a new field to add. Anyway I still don't see why anyone cares about this issue. The Bitcoin protocol does not and never has required that all messages have a fixed number of fields per version. Any parser written on the assumption it did was just buggy. Look at how tx messages are relayed for the most obvious example of that pattern in action - it's actually the raw byte stream that's stored and relayed to ensure that fields added in new versions aren't dropped during round-tripping. Old versions are supposed to preserve fields from the future. On Thu, Jun 20, 2013 at 9:30 AM, Tamas Blummer ta...@bitsofproof.com wrote: Hi Mike, The issue with the current parser is that those fields are conditionally optional on that there will be no subsequent fields added. If there will be further fields they will become manadory. Why not bump the version and parse the fields as mandatory from then on? This would be backward compatible and cleaner going forward. Tamas Blummer http://bitsofproof.com -- This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development -- This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Missing fRelayTxes in version
On Thu, Jun 20, 2013 at 09:36:40AM +0200, Mike Hearn wrote: Sure but why not do that when there's an actual new field to add? Does anyone have a proposal for a feature that needs a new version field at the moment? There's no point changing the protocol now unless there's actually a new field to add. Anyway I still don't see why anyone cares about this issue. The Bitcoin protocol does not and never has required that all messages have a fixed number of fields per version. Any parser written on the assumption it did was just buggy. Look at how tx messages are relayed for the most obvious example of that pattern in action - it's actually the raw byte stream that's stored and relayed to ensure that fields added in new versions aren't dropped during round-tripping. Old versions are supposed to preserve fields from the future. Actually, that is not the same issue. What is being argued for here is that the version in the version message itself should indicate which fields are present, so a parser doesn't need to look at the length of the message. That seems like a minor but very reasonable request to me, and it's trivial to do. That doesn't mean that you may receive versions higher than what you know of, and thus messages with fields you don't know about. That doesn't matter, you can just ignore them. I see no problem with raising the protocol version number to indicate all fields up to fRelayTxes are required, if the announced nVersion is above N. In fact, I believe (though haven't checked) all previous additions to the version message were accompanied with a protocol version (then: client version) increase as well. -- Pieter -- This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Optional wallet-linkable address format - Payment Protocol
which could involve proving something to a third party that has not seen
the communication between payer and payee.
OK - I think I follow now. So a third-party who does not see any of the
communication between the payer and payee only knows the HASH160. Let's say
the payee denies receipt of the funds
It's easy to prove what public key it was sent to (it's the preimage), but
you can't prove the parent of that public key. You can provide any number of
ParentPubKey * Multiplier that could have been used, so the 3rd party is
unconvinced by a matching ParentPubKey * Multiplier.
However, if you calculated the destination using: PubKeyParent *
HMAC(Multiplier,PubKeyParent) as Timo said, now if you give the 3rd party a
PubKeyParent and Multiplier (or Addend) that produces the destination
address, you've proven the payment is in fact spendable by PubKeyParent, and
they can't deny receipt. Very cool.
Sorry for echoing this back, it took me a little while to work it out, so
I thought I'd write it down. Hope I got it right...
If you give {PubKey, ChainCode} you do get this feature. If you give
{ParentPubKey, Addend} or {ParentPubKey, Addend, ChainCode} you're back to
having plausible deniability.
If BIP32's CKD'((Kpar, cpar), i) was actually HMAC(HMAC(cpar, i), Kpar) you
could give HMAC(cpar, i) instead of Addend, and then you would get this
feature; a way to 'skip down' a level in the wallet hierarchy, keep the
'chain of custody' so to speak back to the ParentPubKey intact, without
having to disclose the ChainCode. Meh...
Thanks,
--Jeremy
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Re: [Bitcoin-development] Missing fRelayTxes in version
There's no problem, but there's no benefit either. It also locks us in to a potentially problematic guarantee - what if in future we want to have, say, two optional new pieces of data in two different messages. We don't want to require that if version X then you have to implement all features up to and including that point. Essentially the number of fields in a message is like a little version number, just for that message. It adds flexibility to keep it that way, and there's no downside, seeing as that bridge was already crossed and people with parsers that can't handle it need to fix their code anyway. So I have a slight preference for keeping things the way they are, it keeps things flexible for future and costs nothing. On Thu, Jun 20, 2013 at 11:06 AM, Pieter Wuille pieter.wui...@gmail.comwrote: On Thu, Jun 20, 2013 at 09:36:40AM +0200, Mike Hearn wrote: Sure but why not do that when there's an actual new field to add? Does anyone have a proposal for a feature that needs a new version field at the moment? There's no point changing the protocol now unless there's actually a new field to add. Anyway I still don't see why anyone cares about this issue. The Bitcoin protocol does not and never has required that all messages have a fixed number of fields per version. Any parser written on the assumption it did was just buggy. Look at how tx messages are relayed for the most obvious example of that pattern in action - it's actually the raw byte stream that's stored and relayed to ensure that fields added in new versions aren't dropped during round-tripping. Old versions are supposed to preserve fields from the future. Actually, that is not the same issue. What is being argued for here is that the version in the version message itself should indicate which fields are present, so a parser doesn't need to look at the length of the message. That seems like a minor but very reasonable request to me, and it's trivial to do. That doesn't mean that you may receive versions higher than what you know of, and thus messages with fields you don't know about. That doesn't matter, you can just ignore them. I see no problem with raising the protocol version number to indicate all fields up to fRelayTxes are required, if the announced nVersion is above N. In fact, I believe (though haven't checked) all previous additions to the version message were accompanied with a protocol version (then: client version) increase as well. -- Pieter -- This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Missing fRelayTxes in version
I don't get why this is such a contentious change? Before I was able to use asserts to check the expected length of length of messages per protocol version, I could pass in dumb iterators that just parse the byte stream and I could serialize and deserialize a message to check the parser is correct (in debug mode). This 'simple' change causes all that behaviour to be lost. You can no longer just use iterators but must know the remaining length (or if you use std::distance, you can only use specific std containers - not just anything with an iterator and an operator++). You cannot check the deserialization process by serializing the deserialized message and comparing it to the original data (because the bool is always present in the serializer). It's a bit stupid you call it buggy code when this behaviour has never been present in Bitcoin. The BIP doesn't introduce any unwanted side-effects and is a trivial reasonable change. If you want optional fields then the proper way to do it, is to either set a flag in the Services field of the version message to indicate different formats for messages (i.e use this template structure for a message, not that one), introduce a new message (if the changes are big), to approve/improve Stefan's BIP 32 for custom services or to have a value in the byte stream indicating which fields are present (maybe a bitfield or so). Using a quirk of an implementation is just bad form and sloppy coding. Optional fields should have their own mechanism that allows them to remain as optional fields between protocol version upgrades. The bitcoind software can probably be improved too, by checking that the length of the version message is consistent for the protocol version given by the connected node. Right now it makes no assumptions based on that which is a mistake (new clients can broadcast older version messages that don't have all the fields required). Probably the software should penalise hosts which do that. What's the big deal to update the protocol version number from 70001 to 70002? It's not like we'll run out of integers. The field has now gone from optional to required now anyway - that's a behaviour change. It'd be good to enforce that. I see this as a bug. From: Mike Hearn m...@plan99.net To: Pieter Wuille pieter.wui...@gmail.com Cc: Bitcoin Dev bitcoin-development@lists.sourceforge.net; Tamas Blummer ta...@bitsofproof.com Sent: Thursday, June 20, 2013 11:17 AM Subject: Re: [Bitcoin-development] Missing fRelayTxes in version There's no problem, but there's no benefit either. It also locks us in to a potentially problematic guarantee - what if in future we want to have, say, two optional new pieces of data in two different messages. We don't want to require that if version X then you have to implement all features up to and including that point. Essentially the number of fields in a message is like a little version number, just for that message. It adds flexibility to keep it that way, and there's no downside, seeing as that bridge was already crossed and people with parsers that can't handle it need to fix their code anyway. So I have a slight preference for keeping things the way they are, it keeps things flexible for future and costs nothing. On Thu, Jun 20, 2013 at 11:06 AM, Pieter Wuille pieter.wui...@gmail.com wrote: On Thu, Jun 20, 2013 at 09:36:40AM +0200, Mike Hearn wrote: Sure but why not do that when there's an actual new field to add? Does anyone have a proposal for a feature that needs a new version field at the moment? There's no point changing the protocol now unless there's actually a new field to add. Anyway I still don't see why anyone cares about this issue. The Bitcoin protocol does not and never has required that all messages have a fixed number of fields per version. Any parser written on the assumption it did was just buggy. Look at how tx messages are relayed for the most obvious example of that pattern in action - it's actually the raw byte stream that's stored and relayed to ensure that fields added in new versions aren't dropped during round-tripping. Old versions are supposed to preserve fields from the future. Actually, that is not the same issue. What is being argued for here is that the version in the version message itself should indicate which fields are present, so a parser doesn't need to look at the length of the message. That seems like a minor but very reasonable request to me, and it's trivial to do. That doesn't mean that you may receive versions higher than what you know of, and thus messages with fields you don't know about. That doesn't matter, you can just ignore them. I see no problem with raising the protocol version number to indicate all fields up to fRelayTxes are required, if the announced nVersion is above N. In fact, I believe (though haven't checked) all previous additions to the version message were accompanied with
Re: [Bitcoin-development] Missing fRelayTxes in version
Sure, the issue isn't running out of integers, it's that you have to handle the case of truncated messages whether you like it or not so it doesn't add any simplicity. Even if Bitcoin-Qt starts only sending the new field with a new version number, there are tens of thousands of bitcoinj based wallets out there now that send the current version number and the fRelayTx field as well, so you cannot assume anything about whether the field will exist or not based on the version number regardless of what is changed on the C++ side. Assuming you care about your code being able to serve Bloom-filtering clients of course. With regards to relying on quirks, etc, this is the old is the protocol defined by Satoshi's code debate again ... as I said, version messages have always had a variable number of fields. You didn't notice before because it was a long time since any fields were added. Perhaps it's indeed not ideal, perhaps if Bitcoin was designed in 2013 it'd be using protobufs or some other pre-packaged serialization system. But it is what it is. On Thu, Jun 20, 2013 at 12:37 PM, Turkey Breast turkeybre...@yahoo.comwrote: I don't get why this is such a contentious change? Before I was able to use asserts to check the expected length of length of messages per protocol version, I could pass in dumb iterators that just parse the byte stream and I could serialize and deserialize a message to check the parser is correct (in debug mode). This 'simple' change causes all that behaviour to be lost. You can no longer just use iterators but must know the remaining length (or if you use std::distance, you can only use specific std containers - not just anything with an iterator and an operator++). You cannot check the deserialization process by serializing the deserialized message and comparing it to the original data (because the bool is always present in the serializer). It's a bit stupid you call it buggy code when this behaviour has never been present in Bitcoin. The BIP doesn't introduce any unwanted side-effects and is a trivial reasonable change. If you want optional fields then the proper way to do it, is to either set a flag in the Services field of the version message to indicate different formats for messages (i.e use this template structure for a message, not that one), introduce a new message (if the changes are big), to approve/improve Stefan's BIP 32 for custom services or to have a value in the byte stream indicating which fields are present (maybe a bitfield or so). Using a quirk of an implementation is just bad form and sloppy coding. Optional fields should have their own mechanism that allows them to remain as optional fields between protocol version upgrades. The bitcoind software can probably be improved too, by checking that the length of the version message is consistent for the protocol version given by the connected node. Right now it makes no assumptions based on that which is a mistake (new clients can broadcast older version messages that don't have all the fields required). Probably the software should penalise hosts which do that. What's the big deal to update the protocol version number from 70001 to 70002? It's not like we'll run out of integers. The field has now gone from optional to required now anyway - that's a behaviour change. It'd be good to enforce that. I see this as a bug. -- *From:* Mike Hearn m...@plan99.net *To:* Pieter Wuille pieter.wui...@gmail.com *Cc:* Bitcoin Dev bitcoin-development@lists.sourceforge.net; Tamas Blummer ta...@bitsofproof.com *Sent:* Thursday, June 20, 2013 11:17 AM *Subject:* Re: [Bitcoin-development] Missing fRelayTxes in version There's no problem, but there's no benefit either. It also locks us in to a potentially problematic guarantee - what if in future we want to have, say, two optional new pieces of data in two different messages. We don't want to require that if version X then you have to implement all features up to and including that point. Essentially the number of fields in a message is like a little version number, just for that message. It adds flexibility to keep it that way, and there's no downside, seeing as that bridge was already crossed and people with parsers that can't handle it need to fix their code anyway. So I have a slight preference for keeping things the way they are, it keeps things flexible for future and costs nothing. On Thu, Jun 20, 2013 at 11:06 AM, Pieter Wuille pieter.wui...@gmail.comwrote: On Thu, Jun 20, 2013 at 09:36:40AM +0200, Mike Hearn wrote: Sure but why not do that when there's an actual new field to add? Does anyone have a proposal for a feature that needs a new version field at the moment? There's no point changing the protocol now unless there's actually a new field to add. Anyway I still don't see why anyone cares about this issue. The Bitcoin protocol does not and never has required
Re: [Bitcoin-development] Missing fRelayTxes in version
Let's just increase the version number and be done with this discussion. It's a small benefit, but it simplifies things and it's trivial to do. I don't understand how a policy of requiring version increases could limit future extensions: after the version/verack exchange, the protocol version is negotiated between peers, and there is no need for anything optional anymore. Note thay this is just about parsing, not about relaying - you should still relay parts of a message you haven't parsed. But that doesn't apply to the version message anyway, which is the only place where this matters. -- Pieter On 20 Jun 2013 12:38, Turkey Breast turkeybre...@yahoo.com wrote: I don't get why this is such a contentious change? Before I was able to use asserts to check the expected length of length of messages per protocol version, I could pass in dumb iterators that just parse the byte stream and I could serialize and deserialize a message to check the parser is correct (in debug mode). This 'simple' change causes all that behaviour to be lost. You can no longer just use iterators but must know the remaining length (or if you use std::distance, you can only use specific std containers - not just anything with an iterator and an operator++). You cannot check the deserialization process by serializing the deserialized message and comparing it to the original data (because the bool is always present in the serializer). It's a bit stupid you call it buggy code when this behaviour has never been present in Bitcoin. The BIP doesn't introduce any unwanted side-effects and is a trivial reasonable change. If you want optional fields then the proper way to do it, is to either set a flag in the Services field of the version message to indicate different formats for messages (i.e use this template structure for a message, not that one), introduce a new message (if the changes are big), to approve/improve Stefan's BIP 32 for custom services or to have a value in the byte stream indicating which fields are present (maybe a bitfield or so). Using a quirk of an implementation is just bad form and sloppy coding. Optional fields should have their own mechanism that allows them to remain as optional fields between protocol version upgrades. The bitcoind software can probably be improved too, by checking that the length of the version message is consistent for the protocol version given by the connected node. Right now it makes no assumptions based on that which is a mistake (new clients can broadcast older version messages that don't have all the fields required). Probably the software should penalise hosts which do that. What's the big deal to update the protocol version number from 70001 to 70002? It's not like we'll run out of integers. The field has now gone from optional to required now anyway - that's a behaviour change. It'd be good to enforce that. I see this as a bug. -- *From:* Mike Hearn m...@plan99.net *To:* Pieter Wuille pieter.wui...@gmail.com *Cc:* Bitcoin Dev bitcoin-development@lists.sourceforge.net; Tamas Blummer ta...@bitsofproof.com *Sent:* Thursday, June 20, 2013 11:17 AM *Subject:* Re: [Bitcoin-development] Missing fRelayTxes in version There's no problem, but there's no benefit either. It also locks us in to a potentially problematic guarantee - what if in future we want to have, say, two optional new pieces of data in two different messages. We don't want to require that if version X then you have to implement all features up to and including that point. Essentially the number of fields in a message is like a little version number, just for that message. It adds flexibility to keep it that way, and there's no downside, seeing as that bridge was already crossed and people with parsers that can't handle it need to fix their code anyway. So I have a slight preference for keeping things the way they are, it keeps things flexible for future and costs nothing. On Thu, Jun 20, 2013 at 11:06 AM, Pieter Wuille pieter.wui...@gmail.comwrote: On Thu, Jun 20, 2013 at 09:36:40AM +0200, Mike Hearn wrote: Sure but why not do that when there's an actual new field to add? Does anyone have a proposal for a feature that needs a new version field at the moment? There's no point changing the protocol now unless there's actually a new field to add. Anyway I still don't see why anyone cares about this issue. The Bitcoin protocol does not and never has required that all messages have a fixed number of fields per version. Any parser written on the assumption it did was just buggy. Look at how tx messages are relayed for the most obvious example of that pattern in action - it's actually the raw byte stream that's stored and relayed to ensure that fields added in new versions aren't dropped during round-tripping. Old versions are supposed to preserve fields from the future. Actually, that is not the same
Re: [Bitcoin-development] Missing fRelayTxes in version
As I said, there's no benefit. Even if we do that on the C++ side, you still have to handle connections from bitcoinj clients which will send the field with the old version number. You can't assume they'll all be updated simultaneously, even though both the Android app and MultiBit do have update notifications these days and eventually old versions will presumably disappear. Re: flexibility. Let's say version V+1 adds a complicated new set of data to some messages. Not every client wants or needs the feature enabled by them. Now version V+2 adds a simple extension to a basic message that everyone wants/needs. To get the latter feature, all clients now have to support the first feature as well because the version number is monotonic. OK, we can use a service bit to handle these cases, if we anticipate that not all clients will want the first feature. But then again, we can also use the presence of the additional data as the ground truth instead of duplicating that fact. I don't really mind either way. It just seems that parsing always requires you to be able to handle truncated messages anyway (without asserting or crashing), because a bogus client can always send you partial data. So I don't see what effort is saved. On Thu, Jun 20, 2013 at 12:52 PM, Pieter Wuille pieter.wui...@gmail.comwrote: Let's just increase the version number and be done with this discussion. It's a small benefit, but it simplifies things and it's trivial to do. I don't understand how a policy of requiring version increases could limit future extensions: after the version/verack exchange, the protocol version is negotiated between peers, and there is no need for anything optional anymore. Note thay this is just about parsing, not about relaying - you should still relay parts of a message you haven't parsed. But that doesn't apply to the version message anyway, which is the only place where this matters. -- Pieter On 20 Jun 2013 12:38, Turkey Breast turkeybre...@yahoo.com wrote: I don't get why this is such a contentious change? Before I was able to use asserts to check the expected length of length of messages per protocol version, I could pass in dumb iterators that just parse the byte stream and I could serialize and deserialize a message to check the parser is correct (in debug mode). This 'simple' change causes all that behaviour to be lost. You can no longer just use iterators but must know the remaining length (or if you use std::distance, you can only use specific std containers - not just anything with an iterator and an operator++). You cannot check the deserialization process by serializing the deserialized message and comparing it to the original data (because the bool is always present in the serializer). It's a bit stupid you call it buggy code when this behaviour has never been present in Bitcoin. The BIP doesn't introduce any unwanted side-effects and is a trivial reasonable change. If you want optional fields then the proper way to do it, is to either set a flag in the Services field of the version message to indicate different formats for messages (i.e use this template structure for a message, not that one), introduce a new message (if the changes are big), to approve/improve Stefan's BIP 32 for custom services or to have a value in the byte stream indicating which fields are present (maybe a bitfield or so). Using a quirk of an implementation is just bad form and sloppy coding. Optional fields should have their own mechanism that allows them to remain as optional fields between protocol version upgrades. The bitcoind software can probably be improved too, by checking that the length of the version message is consistent for the protocol version given by the connected node. Right now it makes no assumptions based on that which is a mistake (new clients can broadcast older version messages that don't have all the fields required). Probably the software should penalise hosts which do that. What's the big deal to update the protocol version number from 70001 to 70002? It's not like we'll run out of integers. The field has now gone from optional to required now anyway - that's a behaviour change. It'd be good to enforce that. I see this as a bug. -- *From:* Mike Hearn m...@plan99.net *To:* Pieter Wuille pieter.wui...@gmail.com *Cc:* Bitcoin Dev bitcoin-development@lists.sourceforge.net; Tamas Blummer ta...@bitsofproof.com *Sent:* Thursday, June 20, 2013 11:17 AM *Subject:* Re: [Bitcoin-development] Missing fRelayTxes in version There's no problem, but there's no benefit either. It also locks us in to a potentially problematic guarantee - what if in future we want to have, say, two optional new pieces of data in two different messages. We don't want to require that if version X then you have to implement all features up to and including that point. Essentially the number of fields in a message is like a
Re: [Bitcoin-development] CTxIn::nSequence
It's well answered by this stack exchange question. http://bitcoin.stackexchange.com/questions/2025/what-is-txins-sequence On 06/20/2013 05:54 PM, Marko Otbalkana wrote: Could anyone tell me what CTxIn::nSequence is meant for? Best Regards, -Marko -- This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development -- This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
