April 2010 - Darwin-dev - lists.apple.com

Re: c++ exceptions
by Abdulla Kamar 06 Apr '10

06 Apr '10

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :from:date:received:message-id:subject:to:cc:content-type; bh=UlkOBs7w7cIEecPWBwniniI1/CAH4Z06DWPLfPZJ1uE=; b=FjVQl/6bGqKkuMZsn/xq7ns/hdty+3+KN1AXoQnOsMhYLIVlGOPUc+YK+j1r5s16/O rxMESvzz309mYJf/BzyObHl0RXF9/eEciTv5TUCricxg33WC6k2iRFzj7Xo8jy/jHgSU RFlBtMdjhGDA2QpjIRwIUOlL5n/A93tj77RHk= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type; b=FqEMejDk2XAl5hsAF1d3s1w8uXkVbUhh+HATWRxzQUZdtnE8tZIZFnLhF3OXpBIVFd Hw/0qk8kCbDMFMCNwWIwSR01nfDS3Ra/9N0QmHth37Qd7HMwBebYrZ7w2V/qnuzirNcU vKzHVF4SbNpYq0fsGns9s3hTqLFxQYp48wy+s= _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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Re: c++ exceptions
by Jens Alfke 05 Apr '10

05 Apr '10

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On Apr 5, 2010, at 4:31 PM, Uli Kusterer wrote: —Jens _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… C++ supports throw specifiers, too, for both functions and methods. It's just that the defaults are different: If you don't specify a throw specifier, it will let you throw *any* exception. But IIRC, the specifiers are enforced at runtime, not compile time. So if I declare a function as "throw ()", i.e. not allowed to throw anything, it's still allowed to call functions that can throw exceptions. It's just that if an exception actually gets thrown, it'll cause the program to abort. This is IMHO not nearly as useful as detecting exception violations at compile time. This email sent to site_archiver(a)lists.apple.com

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Re: c++ exceptions
by Uli Kusterer 05 Apr '10

05 Apr '10

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On 16.03.2010, at 19:40, Jens Alfke wrote: > Ideally C++ would have the same kind of exception-checking that Java does, so you could declare a function as not throwing any exception and have the compiler enforce that for you. But C++ doesn't work that way. So you just have to be careful to wrap all your entry points, including callbacks, in try/catch blocks. C++ supports throw specifiers, too, for both functions and methods. It's just that the defaults are different: If you don't specify a throw specifier, it will let you throw *any* exception. -- Uli Kusterer "The Witnesses of TeachText are everywhere..." http://www.masters-of-the-void.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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Re: code signing strategies
by Jack Howarth 04 Apr '10

04 Apr '10

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com User-agent: Mutt/1.5.18 (2008-05-17) Is there any documentation available on the syntax for the Entitlements.plist file? The only thing I could find with google was the example... http://wesnoth.repositoryhosting.com/trac/wesnoth_wesnoth/browser/trunk/Ent… I have figured out how to create the required self-signed certificate and codesign with it but the information on manual editting of the entitlements.plist file seems to be unavailable. Thanks in advance for any information. Jack On Wed, Mar 31, 2010 at 10:16:02AM +0200, Jean-Daniel Dupas wrote: > man taskgated can give you some clue about the requirement to access mach ports. > > Le 31 mars 2010 à 06:23, Jack Howarth a écrit : > > > Kevin, > > I tried... > > > > sudo codesign -s - /sw/bin/fsf-gdb > > > > and I still get... > > > > [MacPro:~] howarth% fsf-gdb ./a.out > > GNU gdb (GDB) 7.1 > > Copyright (C) 2010 Free Software Foundation, Inc. > > License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> > > This is free software: you are free to change and redistribute it. > > There is NO WARRANTY, to the extent permitted by law. Type "show copying" > > and "show warranty" for details. > > This GDB was configured as "x86_64-apple-darwin10.3.0". > > For bug reporting instructions, please see: > > <http://www.gnu.org/software/gdb/bugs/>... > > Reading symbols from /Users/howarth/a.out...(no debugging symbols found)...done. > > (gdb) break main > > Breakpoint 1 at 0x100000f4e > > (gdb) r > > Starting program: /Users/howarth/a.out > > Unable to find Mach task port for process-id 44895: (os/kern) failure (0x5). > > (please check gdb is codesigned - see taskgated(8)) > > > > whereas 'sudo fsf-gdb ./a.out' works fine. Looking at the two binaries I see... > > > > [MacPro:~] howarth% codesign -d -vvv /usr/libexec/gdb/gdb-i386-apple-darwin > > Executable=/usr/libexec/gdb/gdb-i386-apple-darwin > > Identifier=com.apple.gdb > > Format=Mach-O universal (i386 ppc7400 x86_64) > > CodeDirectory v=20100 size=17922 flags=0x0(none) hashes=891+2 location=embedded > > CDHash=1f961159e2c4038e658298a52b2f295ff95b2266 > > Signature size=4064 > > Authority=Software Signing > > Authority=Apple Code Signing Certification Authority > > Authority=Apple Root CA > > Info.plist entries=6 > > Sealed Resources=none > > Internal requirements count=1 size=180 > > > > [MacPro:~] howarth% codesign -d -vvv /sw/bin/fsf-gdb > > Executable=/sw/bin/fsf-gdb > > Identifier=org.gnu.gdb > > Format=Mach-O thin (x86_64) > > CodeDirectory v=20100 size=25960 flags=0x2(adhoc) hashes=1293+2 location=embedded > > CDHash=99c0613857a480e69f36eacc158a2d78f2f199af > > Signature=adhoc > > Info.plist entries=4 > > Sealed Resources=none > > Internal requirements count=1 size=104 > > > > Is it significant that Apple's gdb has flags set to 0x0 whereas > > the fsf-gdb shows flags set to 0x2? Any other ideas to try? > > Jack > > > > > > On Tue, Mar 30, 2010 at 09:23:17AM -0700, Kevin Van Vechten wrote: > >> The behavior you describe is the result of changes in recent Mac OS X releases to restrict the use of task_for_pid and related functions that present significant security risks. The goal is to limit use of such functions to the system administrator, and the policy is enforced by the taskgated process. Code signing is required in order to verify that the binary is not maliciously changed out from under any previous approval for use of these functions. Nothing about this policy is unique to gdb. > >> > >> It's possible to generate "ad hoc" code signatures on binaries which generate all the usual checksums for the purposes of integrity checks but do not chain to a trusted authority. It's worth giving the following a try to see if it satisfies the basic requirements of taskgated (I haven't tried it myself): > >> > >> $ sudo codesign -s - /path/to/gdb > >> > >> Kevin > >> > >> On Mar 30, 2010, at 7:18 AM, Jack Howarth wrote: > >> > >>> I am trying to prepare fink packaging of the > >>> new FSF gdb 7.1 release on i386 and x86_64 fink. > >>> Unfortunately Apple's changes in 10.5.8 or later > >>> require that gdb binary be code signed (or run as root) > >>> in order to access the required Mach port for > >>> debugging code. > >>> Are their any code signing gurus here who > >>> could suggest the best approach to cope with this > >>> problem? I am hoping to implement something along > >>> these lines but am unsure if it is feasible. > >>> > >>> 1) Provide an openssl certificate bundled with the > >>> fsf-gdb fink package. > >>> 2) Provide a shell script which when run, guides > >>> the user through the steps of loading the provided > >>> certificate manually in the KeyChain application and then > >>> code signs the fsf-gdb binary from within the shell > >>> script using command line tools. My understanding is > >>> that only the creation and/or loading of the openssl > >>> certificates no longer have CLI tool access. > >>> 3) Have a postinstall script in the fsf-gdb that > >>> would check if the certificate exists in the Keychain > >>> when the fsf-gdb package is installed, reinstalled > >>> or upgraded and launch the shell script described in > >>> step 2 if not present. Otherwise it would just > >>> code sign the newly installed fsf gdb binary again. > >>> > >>> Thanks in advance for any advice on these issues. > >>> Needless to say, the FSF gdb developers were a > >>> tad miffed that this restriction popped up after > >>> all the effort to support intel darwin in the official > >>> FSF gdb releases. > >>> Jack > >>> ps It will be essential to have access to a working > >>> FSF gdb 7.1 debugger for users who want to use the > >>> upcoming FSF gcc 4.5 compiler release. There are > >>> changes in debug code generation which are incompatible > >>> with the older gdb releases. > > _______________________________________________ > > Do not post admin requests to the list. They will be ignored. > > Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) > > Help/Unsubscribe/Update your Subscription: > > http://lists.apple.com/mailman/options/darwin-dev/devlists%40shadowlab.org > > > > This email sent to devlists(a)shadowlab.org > > -- Jean-Daniel > > > _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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Re: Socket read tuning on Mac OS X
by Terry Lambert 03 Apr '10

03 Apr '10

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com I spoke too soon here, and misrepresented things. -- Terry _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… On Apr 2, 2010, at 4:06 PM, Terry Lambert wrote: On Apr 2, 2010, at 7:18 AM, Jakub Bednar wrote: I have tried SO_RCVLOWAT along with SO_RCVTIMEO options, but this is not the way. Poll() does not respect SO_RCVLOWAT and the socket will not give me less data but return an error when SO_RCVTIMEO timeout expires. SO_RCVLOWAT only applies to UNIX domain sockets or FIFOs, where there is not potentially an administrative or system limit that will prevent enough data accumulating in order to satisfy the low watermark. It's going to have no effect because it's not supposed to have any effect: you could starvation deadlock yourself otherwise, which could be used to stage a local DOS. This is true on most other UNIX-like systems as well. One exception is "accept filters"-based systems with kernel pre-parsing of data contents for recognition of complete messages; another is the NCP streams MUX in NetWare for UNIX, which also recognizes complete messages, and does not send unchunked data up to user space. These are dangerous from a security perspective because they allow a user space process to download interpreted code intended to run in supervisor mode. NB: As To A.M.'s suggestion, the NOTE_LOWAT for kqueue() is only respected for sockets, pipes, and BPF (Berkeley Packet Filter); unless you are doing raw ethernet frames via BPF, this will unfortunately not help you out. A.M.'s suggestion isn't going to work if the poll() didn't work as you note. The SO_RCVLOWAT is supposed to work on all sockets, so why it seems to not be working in your case is at this point unknown; there are a couple of theories so far. Stay tuned. This email sent to site_archiver(a)lists.apple.com

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Re: Socket read tuning on Mac OS X
by Terry Lambert 02 Apr '10

02 Apr '10

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Hello list, Hope that helps! -- Terry _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… On Apr 2, 2010, at 7:18 AM, Jakub Bednar wrote: I have written an application, that communicates using HTTP protocol. During testing, I found out, that with high download speed the CPU usage of my application is pretty high on some systems. Performance testing with Shark showed, that the problem is in a socket read() operation. I'm using the poll()/read()/write() mechanism specified by POSIX. On the systems were the CPU usage is normal, the read() system call regularly returns about 10kB of data per read. These systems have a default Ethernet driver (e.g. my Mac Book Pro with nvenet.kext driver) On the systems with high CPU usage, the read() system call regularly returns only about 1.4kB of data per read, leading to 10x bigger overhead ===> higher CPU usage. An example of this system is an iMac with AppleYukon2.kext driver or a Mac Book Air with Ethernet over USB. I have checked all the sysctl options and there is no difference. It seems to me, that this is a driver issue. If I put a small sleep before every read, more data are returned per read(), leading to rapid drop of CPU usage at a cost of slight drop of download speed. So I wonder, is there a way how to reconfigure a socket to tell him something like: "Give me about xxx kB of data per read, but if that amount is not available in a specified time, give me what you have."? It's technically an issue with amortization of overhead on non-chunked data streams in your code. When data arrives at a protocol interface, it accumulates in a local hardware buffer until a hardware dependent amount of time has elapsed (if the hardware supports this), a transfer unit size has been reached (if the hardware partitions its input buffer), or that buffer hits a high water mark (to prevent hardware buffer overrun). Then it sends an interrupt. Various low level drivers have various thresholds, depending on the device firmware and buffer size that it accumulates before it has to do a data transfer, and whether or not the device allows the host to control them. Once the data transfer happens, though, the upper level driver thread wakes up, and calls proto_input() to input the data into the network stack. This hashes based on the protocol ID to AF_INET to ip_input(), and then IPPROTO_TCP to go to tcp_input(). However, the TCP data is also then processed into the receiving socket buffer (up to the administrative limit on the socket), and then anything sleeping on the socket, like a poll in the program that opened it, is woken up. There's no guarantee about how much data is going to have arrived (before the wakeup) and be sitting in the socket by the time you get around to reading (i.e. additional data received subsequent to the wakeup). In other words, there's a queue retention time in the hardware, a queue retention time in the stack, and a queue retention time in the socket buffer, and a propagation latency in each case, plus a latency between the notification, your process being scheduled, and you doing the read. I have tried SO_RCVLOWAT along with SO_RCVTIMEO options, but this is not the way. Poll() does not respect SO_RCVLOWAT and the socket will not give me less data but return an error when SO_RCVTIMEO timeout expires. SO_RCVLOWAT only applies to UNIX domain sockets or FIFOs, where there is not potentially an administrative or system limit that will prevent enough data accumulating in order to satisfy the low watermark. It's going to have no effect because it's not supposed to have any effect: you could starvation deadlock yourself otherwise, which could be used to stage a local DOS. This is true on most other UNIX-like systems as well. One exception is "accept filters"-based systems with kernel pre- parsing of data contents for recognition of complete messages; another is the NCP streams MUX in NetWare for UNIX, which also recognizes complete messages, and does not send unchunked data up to user space. These are dangerous from a security perspective because they allow a user space process to download interpreted code intended to run in supervisor mode. NB: As To A.M.'s suggestion, the NOTE_LOWAT for kqueue() is only respected for sockets, pipes, and BPF (Berkeley Packet Filter); unless you are doing raw ethernet frames via BPF, this will unfortunately not help you out. Please, any ideas how to solve this? Use a read thread, wait for data to be available on the socket, and add your own latency after that so that the read is delayed after the arrival of the first byte becoming available until (hopefully) other bytes have become available. By isolating it to a separate thread, you will only put a latency on the individual read itself in the thread, and you will avoid introducing a processing latency of the pre- read delay prior to operating on the data. In other words, your read thread will always sleep after data is available, but as long as your data is arriving in a continuous stream, you will amortize only a single read latency across all the processing you end up doing (much in the same way that the sliding window in the TCP protocol amortizes the ACK round trip time of 2*MSL over the entire data stream, rather than paying a per-packet penalty). This will keep the data fetch overhead down, while at the same time not slowing down your processing waiting for the delay before reading the data. Use whatever producer/consumer design pattern you like best to move the received data buffers between the read thread and the processing thread (I would do it by having a list of work items in both, and protecting insertion and deletion with a lock so that transferring work is simply moving a data structure from one list to another under the lock, rather than copying the data). This email sent to site_archiver(a)lists.apple.com

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Re: Socket read tuning on Mac OS X
by A.M. 02 Apr '10

02 Apr '10

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On Apr 2, 2010, at 10:43 AM, Mo McRoberts wrote: > On Fri, Apr 2, 2010 at 15:18, Jakub Bednar <jakub.bednar(a)avg.com> wrote: > > "Give me about xxx kB of data per read, but if >> that amount is not available in a specified time, give me what you have."? > > ioctl(fd, FIONREAD, &nbytes) in combination with a short sleep, > perhaps? i.e., if nbytes is below the threshold, sleep for a short > period and test again, if it's increased but still below the > threshold, continue sleeping; if it's unchanged or above the > threshold, read what's there Jakube, You should look at kqueue. >From man kqueue: Other socket descriptors return when there is data to be read, subject to the SO_RCVLOWAT value of the socket buffer. This may be overridden with a per- filter low water mark at the time the filter is added by setting the NOTE_LOWAT flag in fflags, and specifying the new low water mark in data. On return, data contains the number of bytes of proto- col data available to read. You can easily implement poll using kqueue if you like. Cheers, M _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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Re: Security issue in developing Mac code -- not sure where to discuss
by Jens Alfke 02 Apr '10

02 Apr '10

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On Apr 2, 2010, at 1:05 PM, Jay Reynolds Freeman wrote: I am not sure where to discuss issues related to developing Macintosh code that uses the Internet to transmit data in a secure manner: The app is not a web-server-and-client kind of thing; I expect to be using Internet socket connections directly, from within the various instances of the application. So far, I have described a very general programming issue -- probably too general for this group. What I am wondering about is what special support is available for this kind of thing based on the fact that I am using Macintoshes, and have all the facilities of MacOS and Xcode to develop and run with. —Jens _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… macnetworkprog is the general networking list; that's probably the best place for this. And discussion of Mac crypto/security APIs is at the apple-cdsa list (great name, no?) It depends on what levels of APIs you're comfortable with and will integrate best with your code. At the lowest level you have the standard BSD socket API. At a higher level, but still procedural, are the CFNetwork APIs (specifically CFSocket and CFStream). In Objective- C there are some OOP wrappers around CFNetwork in the form of NSStream etc., although they're somewhat incomplete. If you're concerned about security, SSL is a good choice. The SecureTransport API implements that on whatever stream layer you want to use. Mac OS also comes with the cross-platform OpenSSL library which does basically the same thing. If you use CFStream you can enable SSL transport pretty easily without having to know the lower level APIs. Using SSL in a peer-to-peer environment means messing with X.509 certificates and key-pairs, and secure storage of them. The "Sec-" prefixed APIs in the Security framework deal with that. (OpenSSL has its own APIs too.) You might be interested in a framework I wrote called MYNetwork which is a very high-level Objective-C API for networking, including SSL support and Bonjour discovery. It wraps the above APIs and hides a lot of the complexity. http://bitbucket.org/snej/mynetwork/ This email sent to site_archiver(a)lists.apple.com

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Re: Security issue in developing Mac code -- not sure where to discuss
by Graham Lee 02 Apr '10

02 Apr '10

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Hi Jay, Cheers, Graham Lee http://blog.securemacprogramming.com Author of Professional Cocoa Application Security http://www.amazon.co.uk/gp/product/0470525959?ie=UTF8&tag=thaeofer-21&linkC… I am not sure where to discuss issues related to developing Macintosh code that uses the Internet to transmit data in a secure manner: If anyone can suggest a better list, by all means say so and I will go there. Meanwhile ... I am developing a Macintosh application which will be capable of running on a cluster of Macs; that is, each of a number of Macs will be running a copy of the application (or of part of it) and the different Macs will communicate with each other to coordinate activity and share data: The app is not a web-server-and-client kind of thing; I expect to be using Internet socket connections directly, from within the various instances of the application. So far, I have described a very general programming issue -- probably too general for this group. What I am wondering about is what special support is available for this kind of thing based on the fact that I am using Macintoshes, and have all the facilities of MacOS and Xcode to develop and run with. The app is a clustered version of Wraith Scheme, a parallel Scheme implementation for the Mac that I have been developing for some years. See the "Software" page of my web site (URL below) if you are terminally curious. Wraith Scheme is very powerful, and a malicious person who accessed it remotely could do immense damage to the system it is running on. (The actual number of users of any such clusters is likely minuscule, so the probability that anyone will try to do such a thing is small, but I would like to handle the security issues as professionally as I can.) Comments are welcome, as are suggestions to go elsewhere. (People are *always* telling me where to go ...) -- Jay Reynolds Freeman --------------------- Jay_Reynolds_Freeman(a)mac.com http://web.mac.com/jay_reynolds_freeman (personal web site) _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/leeg%40thaesofereode.info _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… I think that to understand the security requirements of your app, we need to know more about what it does. Are all the systems on the same subnet? What data is sent between them? Should such data be private, what would happen if it were tanpered with? With what privilege do different components run? Once you've pinned down the security requirements, then we can look at the technology needed to implement them. P.s. If people do think you're off-topic here, I'd suggest apple-cdsa (the common data security architecture list) or stackoverflow.com. On 2 Apr 2010, at 21:05, Jay Reynolds Freeman <jay_reynolds_freeman(a)mac.com > wrote: This email sent to leeg(a)thaesofereode.info This email sent to site_archiver(a)lists.apple.com

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Security issue in developing Mac code -- not sure where to discuss
by Jay Reynolds Freeman 02 Apr '10

02 Apr '10

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com I am not sure where to discuss issues related to developing Macintosh code that uses the Internet to transmit data in a secure manner: If anyone can suggest a better list, by all means say so and I will go there. Meanwhile ... I am developing a Macintosh application which will be capable of running on a cluster of Macs; that is, each of a number of Macs will be running a copy of the application (or of part of it) and the different Macs will communicate with each other to coordinate activity and share data: The app is not a web-server-and-client kind of thing; I expect to be using Internet socket connections directly, from within the various instances of the application. So far, I have described a very general programming issue -- probably too general for this group. What I am wondering about is what special support is available for this kind of thing based on the fact that I am using Macintoshes, and have all the facilities of MacOS and Xcode to develop and run with. The app is a clustered version of Wraith Scheme, a parallel Scheme implementation for the Mac that I have been developing for some years. See the "Software" page of my web site (URL below) if you are terminally curious. Wraith Scheme is very powerful, and a malicious person who accessed it remotely could do immense damage to the system it is running on. (The actual number of users of any such clusters is likely minuscule, so the probability that anyone will try to do such a thing is small, but I would like to handle the security issues as professionally as I can.) Comments are welcome, as are suggestions to go elsewhere. (People are *always* telling me where to go ...) -- Jay Reynolds Freeman --------------------- Jay_Reynolds_Freeman(a)mac.com http://web.mac.com/jay_reynolds_freeman (personal web site) _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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