Re: [Bitcoin-development] Bitcoin Core trial balloon: splitting blockchain engine and wallet
On Fri, Feb 21, 2014 at 04:11:06PM +0530, Mike Hearn wrote: On Fri, Feb 21, 2014 at 12:20 PM, Jeff Garzik jgar...@bitpay.com wrote: RE doesn't buy you anything Today, when unlocked, plaintext private keys reside in the same address space as the blockchain engine (BCE). Process separation increases the difficulty of accessing key data from the BCE, even presuming a normal, no-chroot, same-uid, parent-child process relationship. The attack surface is clearly changed from one buffer overflow can touch this data. Regardless, the split makes sense given existing modularity and coding directions. I wouldn't micro-focus on the sandbox word. I'm not sure it does really - typical C/C++ exploits let you run arbitrary code, at which point you can quite easily ptrace the other process and do whatever you want with it, or read /proc/pid/mem etc. But process separation is certainly a prerequisite for sandboxing so I'm not arguing against such a change, just pointing out that it requires some work to really get the benefits. Also an SPV Bitcoin Core would obviously be of tremendous utility all by itself ... The seccomp mechanism would work well here - it's a syscall whitelister, which makes ptrace useless, among other things. Used by Chrome as of v23 to sandbox the renderers. We'd probably need to use it with chroot and whitelist the open() call so that the existing code can create new blockfiles and do whatever leveldb does. -- 'peter'[:-1]@petertodd.org 000112c53364597954e79cc38f1ba7826a6420ad22a6f3be2932 signature.asc Description: Digital signature -- Managing the Performance of Cloud-Based Applications Take advantage of what the Cloud has to offer - Avoid Common Pitfalls. Read the Whitepaper. http://pubads.g.doubleclick.net/gampad/clk?id=121054471iu=/4140/ostg.clktrk___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
[Bitcoin-development] Bitcoin Core trial balloon: splitting blockchain engine and wallet
[Meta: Bitcoin Core is the newfangled branding of bitcoind / Bitcoin-Qt reference implementation, in case you wondering.] Several sites, including BitPay, use bitcoind outside the standard role of wallet software. bitcoind can be used purely for payment network access and management. I call this the border router role. Upcoming version 0.9 will feature the ability to disable the bitcoind wallet at compile time or runtime. This permits a more optimized border router profile, reducing process size by 40-200MB according to some reports. Recent IRC discussion have floated a rough proposal for a wallet next-step: Running the Bitcoin Core wallet as a separate process, a separate binary, from the blockchain engine. The wallet process would communicate with the blockchain engine using existing RPC and P2P channels, becoming a real SPV client. This accomplishes a longstanding security goal of sandboxing away wallet keys and sensitive data from the network-exposed P2P engine, in a separate process, among other benefits. Simple forking was explored a bit. I did some hacking in that direction, as it seemed potentially lightweight and somewhat easy to me: https://github.com/jgarzik/bitcoin/tree/fork fork+pipe is fine for Linux and OSX/BSD. However, Windows requires an exec-like solution to create a new process. MSDN does give us a Unix-pipe-like solution: http://msdn.microsoft.com/en-us/library/edze9h7e%28v=vs.80%29.aspx Others pointed to boost interprocess communication APIs, which come with their own set of caveats. Such a solution would involve a brand new IPC protocol, and lots of brand new glue code. Separate programs seems better. Windows forces us to achieve process separation via exec-like method. We already have IPC: RPC + P2P. Modern OS's make localhost sockets just about as fast as other IPCs methods. Linux, at least, employs zero-copy for localhost sockets in many situations, similar to the kernel's pipe tricks. Pieter has been working on headers-first sync: https://github.com/bitcoin/bitcoin/pull/2964 Moving along this wallet/blockchain engine split requires upping the reviewtest bandwidth on Pieter's PRs, such as https://github.com/bitcoin/bitcoin/pull/3514 Unsure how much of the separate-binary discussion Gavin saw, so cc'd for emphasis. -- Jeff Garzik Bitcoin core developer and open source evangelist BitPay, Inc. https://bitpay.com/ -- Managing the Performance of Cloud-Based Applications Take advantage of what the Cloud has to offer - Avoid Common Pitfalls. Read the Whitepaper. http://pubads.g.doubleclick.net/gampad/clk?id=121054471iu=/4140/ostg.clktrk ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Bitcoin Core trial balloon: splitting blockchain engine and wallet
Bear in mind a separate process doesn't buy you anything without a sandbox, and those are expensive (in terms of complexity). On 21 Feb 2014 11:40, Jeff Garzik jgar...@bitpay.com wrote: [Meta: Bitcoin Core is the newfangled branding of bitcoind / Bitcoin-Qt reference implementation, in case you wondering.] Several sites, including BitPay, use bitcoind outside the standard role of wallet software. bitcoind can be used purely for payment network access and management. I call this the border router role. Upcoming version 0.9 will feature the ability to disable the bitcoind wallet at compile time or runtime. This permits a more optimized border router profile, reducing process size by 40-200MB according to some reports. Recent IRC discussion have floated a rough proposal for a wallet next-step: Running the Bitcoin Core wallet as a separate process, a separate binary, from the blockchain engine. The wallet process would communicate with the blockchain engine using existing RPC and P2P channels, becoming a real SPV client. This accomplishes a longstanding security goal of sandboxing away wallet keys and sensitive data from the network-exposed P2P engine, in a separate process, among other benefits. Simple forking was explored a bit. I did some hacking in that direction, as it seemed potentially lightweight and somewhat easy to me: https://github.com/jgarzik/bitcoin/tree/fork fork+pipe is fine for Linux and OSX/BSD. However, Windows requires an exec-like solution to create a new process. MSDN does give us a Unix-pipe-like solution: http://msdn.microsoft.com/en-us/library/edze9h7e%28v=vs.80%29.aspx Others pointed to boost interprocess communication APIs, which come with their own set of caveats. Such a solution would involve a brand new IPC protocol, and lots of brand new glue code. Separate programs seems better. Windows forces us to achieve process separation via exec-like method. We already have IPC: RPC + P2P. Modern OS's make localhost sockets just about as fast as other IPCs methods. Linux, at least, employs zero-copy for localhost sockets in many situations, similar to the kernel's pipe tricks. Pieter has been working on headers-first sync: https://github.com/bitcoin/bitcoin/pull/2964 Moving along this wallet/blockchain engine split requires upping the reviewtest bandwidth on Pieter's PRs, such as https://github.com/bitcoin/bitcoin/pull/3514 Unsure how much of the separate-binary discussion Gavin saw, so cc'd for emphasis. -- Jeff Garzik Bitcoin core developer and open source evangelist BitPay, Inc. https://bitpay.com/ -- Managing the Performance of Cloud-Based Applications Take advantage of what the Cloud has to offer - Avoid Common Pitfalls. Read the Whitepaper. http://pubads.g.doubleclick.net/gampad/clk?id=121054471iu=/4140/ostg.clktrk ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development -- Managing the Performance of Cloud-Based Applications Take advantage of what the Cloud has to offer - Avoid Common Pitfalls. Read the Whitepaper. http://pubads.g.doubleclick.net/gampad/clk?id=121054471iu=/4140/ostg.clktrk___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Bitcoin Core trial balloon: splitting blockchain engine and wallet
RE doesn't buy you anything Today, when unlocked, plaintext private keys reside in the same address space as the blockchain engine (BCE). Process separation increases the difficulty of accessing key data from the BCE, even presuming a normal, no-chroot, same-uid, parent-child process relationship. The attack surface is clearly changed from one buffer overflow can touch this data. Regardless, the split makes sense given existing modularity and coding directions. I wouldn't micro-focus on the sandbox word. On Fri, Feb 21, 2014 at 1:27 AM, Mike Hearn m...@plan99.net wrote: Bear in mind a separate process doesn't buy you anything without a sandbox, and those are expensive (in terms of complexity). On 21 Feb 2014 11:40, Jeff Garzik jgar...@bitpay.com wrote: [Meta: Bitcoin Core is the newfangled branding of bitcoind / Bitcoin-Qt reference implementation, in case you wondering.] Several sites, including BitPay, use bitcoind outside the standard role of wallet software. bitcoind can be used purely for payment network access and management. I call this the border router role. Upcoming version 0.9 will feature the ability to disable the bitcoind wallet at compile time or runtime. This permits a more optimized border router profile, reducing process size by 40-200MB according to some reports. Recent IRC discussion have floated a rough proposal for a wallet next-step: Running the Bitcoin Core wallet as a separate process, a separate binary, from the blockchain engine. The wallet process would communicate with the blockchain engine using existing RPC and P2P channels, becoming a real SPV client. This accomplishes a longstanding security goal of sandboxing away wallet keys and sensitive data from the network-exposed P2P engine, in a separate process, among other benefits. Simple forking was explored a bit. I did some hacking in that direction, as it seemed potentially lightweight and somewhat easy to me: https://github.com/jgarzik/bitcoin/tree/fork fork+pipe is fine for Linux and OSX/BSD. However, Windows requires an exec-like solution to create a new process. MSDN does give us a Unix-pipe-like solution: http://msdn.microsoft.com/en-us/library/edze9h7e%28v=vs.80%29.aspx Others pointed to boost interprocess communication APIs, which come with their own set of caveats. Such a solution would involve a brand new IPC protocol, and lots of brand new glue code. Separate programs seems better. Windows forces us to achieve process separation via exec-like method. We already have IPC: RPC + P2P. Modern OS's make localhost sockets just about as fast as other IPCs methods. Linux, at least, employs zero-copy for localhost sockets in many situations, similar to the kernel's pipe tricks. Pieter has been working on headers-first sync: https://github.com/bitcoin/bitcoin/pull/2964 Moving along this wallet/blockchain engine split requires upping the reviewtest bandwidth on Pieter's PRs, such as https://github.com/bitcoin/bitcoin/pull/3514 Unsure how much of the separate-binary discussion Gavin saw, so cc'd for emphasis. -- Jeff Garzik Bitcoin core developer and open source evangelist BitPay, Inc. https://bitpay.com/ -- Managing the Performance of Cloud-Based Applications Take advantage of what the Cloud has to offer - Avoid Common Pitfalls. Read the Whitepaper. http://pubads.g.doubleclick.net/gampad/clk?id=121054471iu=/4140/ostg.clktrk ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development -- Jeff Garzik Bitcoin core developer and open source evangelist BitPay, Inc. https://bitpay.com/ -- Managing the Performance of Cloud-Based Applications Take advantage of what the Cloud has to offer - Avoid Common Pitfalls. Read the Whitepaper. http://pubads.g.doubleclick.net/gampad/clk?id=121054471iu=/4140/ostg.clktrk ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
