Development Multiverse

Jeff Atwood just put up a post, complete with a catchy analogy, that provides a good pedagogic overview of branching and merging. Many aspects of these concepts were discussed in the comments, most providing support for the perspective that Branching Is Hard(TM). My own perspective is that one of the chief reasons this is 'all very difficult' is because individual developers only have exposure to branching in the scope of the entire project and that exposure is most often very limited. In the absence of explicit personal experience with managing branching and merging I think it will always be Hard. Queue extolling the virtues of distributed version control...

Coming late to the dVCS party, I discovered Mercurial (Hg) a few months ago. A dVCS like Hg allows you to have full version control over your own work; the prime benefit in this context, you can easily play with different branching schemes. You find out very quickly just how many 'parallel universes' you can juggle, or at least I did (with great power comes great...blah blah blah). In this circumstance, the individual developer can acquire experience with the complete process of managing branching and merging, which will help them grok the activities within the greater project context perhaps making the process Easier(TM).

I think the discussion of version control in the general context of software engineering is an interesting one, for more discussion check out some threads on Reddit (can't find the bloody one I'm looking for right now, argh!), this essay by David Wheeler (of Secure Programming for Linux and Unix HOWTO fame), and the Mercurial Book.

Taxonomy Work

Flipping through a slide deck of Steve Christey and Robert Martin's, Mitre CWE Being Explicit Slides (ppt) made me think of Dave Aitel's quip from a few days ago "Taxonomy = wrong" or put less, or more, banally by our man Mulder:

"We fail to anticipate the unforeseen or expect the unexpected in a universe of infinite possibilities we may find ourselves at the mercy of anyone or anything that cannot be programmed, categorized or easily referenced..."

I think it quite obvious that this is the position we'll consistently be at if we approach constructing and assessing systems with a semi-ordered list of instructions *cough*software security book*cough* in hand and less than half a clue.

Creating a taxonomy of vulnerabilities is but one aspect of attempting to understand software security, if efforts such as Common Weakness Enumeration were just about creating such a list then perhaps we can label the whole effort as misguided, but the stated process here is to develop understanding. When we have some basis for that, we can do something with it and then, hopefully, our software won't suck wet sweaty moose testicles, or at least as much as it does now.

CWE attempts to unifies a number of existing software security resources, some of my favourites being:

• The Seven Pernicious Kingdoms (more here)

• PLOVER - Preliminary List Of Vulnerability Examples for Researchers

• WASC Threat Classification

• OWASP Guide, CLASP, and most everything else...

Which is still just a small selection of the great software security resources out there, for further interest check out work by Brian Chess, Gary McGraw, John Viega, Steve Christey, and Robert Martin; I'm usually very impressed with all their efforts.

dmesg and OpenSSL speed pr0n

I installed a Soekris vpn1401 in my net4801 a couple weeks ago to improve the performance of the OpenVPN (SSL) and IPSec VPNs I have running over the wireless. This morning I decided to run 'openssl speed' to see what the raw performance is like in rough comparison to what I remember from running the test without the card installed. Generally speaking, these results represent 3x+ speed increases over the stock hardware.

OpenBSD 4.1 (GENERIC) #1435: Sat Mar 10 19:07:45 MST 2007
    deraadt@i386.openbsd.org:/usr/src/sys/arch/i386/compile/GENERIC
cpu0: Geode(TM) Integrated Processor by National Semi ("Geode by NSC" 586-class) 267 
MHz
cpu0: FPU,TSC,MSR,CX8,CMOV,MMX
cpu0: TSC disabled
real mem  = 133787648 (130652K)
avail mem = 114675712 (111988K)

...
hifn0 at pci0 dev 10 function 0 "Hifn 7955/7954" rev 0x00: LZS 3DES ARC4 MD5 SHA1 RNG AES PK, 32KB dram, irq 11
...

# sysctl -a | grep crypto                                                      
kern.malloc.kmemnames=free,mbuf,devbuf,debug,pcb,routetbl,,fragtbl,,ifaddr,soopts,sysctl,,,ioctlops,,,,,iov,mount,,NFS_req,NFS_mount,
NFS_node,vnodes,namecache,UFS_quota,UFS_mount,shm,VM_map,sem,dirhash,,VM_pmap,,,,file,file_desc,,proc,subproc,VFS_cluster,,,MFS_node,
,,Export_Host,NFS_srvsock,NFS_uid,NFS_daemon,ip_moptions,in_multi,ether_multi,mrt,ISOFS_mount,ISOFS_node,MSDOSFS_mount,MSDOSFS_fat,MS
DOSFS_node,ttys,exec,miscfs_mount,,adosfs_mount,,adosfs_anode,,,adosfs_bitmap,,,pfkey_data,tdb,xform_data,,pagedep,inodedep,newblk,,,
indirdep,,,,,,,,,VM_swap,,,,,RAIDframe_data,UVM_amap,UVM_aobj,,USB,USB_device,USB_HC,,memdesc,,,crypto_data,,IPsec_creds,packet_tags,
1394ctl,1394data,emuldata,,,,,,,,,ip6_options,NDP,ip6rr,rp_addr,temp,NTFS_mount,NTFS_node,NTFS_fnode,NTFS_dir,NTFS_hash_tables,NTFS_f
ile_attr,NTFS_resident_data_,NTFS_decomp,NTFS_vrun,kqueue,bluetooth,bwmeter,UDF_mount,UDF_file_entry,UDF_file_id
kern.malloc.kmemstat.crypto_data=(inuse = 1, calls = 1, memuse = 1K, limblocks = 0, mapblocks = 0, maxused = 1K, limit = 19596K, spar
e = 0, sizes = (1024))
kern.usercrypto=1
kern.cryptodevallowsoft=0
kern.userasymcrypto=1

# openssl speed
...
OpenSSL 0.9.7j 04 May 2006
built on: date not available
options:bn(64,32) md2(int) rc4(idx,int) des(ptr,risc1,16,long) aes(partial) blow
fish(idx) 
compiler: information not available
available timing options: USE_TOD HZ=100 [sysconf value]
timing function used: getrusage
The 'numbers' are in 1000s of bytes per second processed.
type             16 bytes     64 bytes    256 bytes   1024 bytes   8192 bytes
md2                 88.25k      189.38k      266.19k      296.55k      306.63k
mdc2                 0.00         0.00         0.00         0.00         0.00 
md4                642.82k     2348.02k     7230.63k    15670.35k    22294.59k
md5                563.68k     2022.73k     6286.69k    13357.90k    19464.88k
hmac(md5)          934.52k     3290.12k     8924.16k    16656.01k    21061.87k
sha1               540.19k     1713.66k     4316.22k     7282.86k     8415.84k
rmd160             416.16k     1356.93k     3403.01k     5638.49k     6821.26k
rc4               9863.87k    11587.07k    12052.14k    12217.07k    12118.70k
des cbc           1909.22k     2004.50k     2053.72k     2044.59k     2015.23k
des ede3           731.05k      753.26k      755.46k      763.26k      752.12k
idea cbc             0.00         0.00         0.00         0.00         0.00 
rc2 cbc           1339.74k     1414.02k     1428.31k     1436.29k     1439.38k
rc5-32/12 cbc        0.00         0.00         0.00         0.00         0.00 
blowfish cbc      3027.14k     3350.16k     3443.98k     3457.37k     3456.42k
cast cbc          3009.48k     3380.79k     3482.05k     3493.65k     3476.86k
aes-128 cbc       2784.76k     2956.69k     2964.86k     3009.17k     2959.56k
aes-192 cbc       2430.26k     2565.73k     2569.34k     2601.88k     2558.63k
aes-256 cbc       2163.65k     2262.30k     2266.64k     2298.75k     2276.51k
                  sign    verify    sign/s verify/s
rsa  512 bits 0.016715s 0.002043s     59.8    489.6
rsa 1024 bits 0.076623s 0.004701s     13.1    212.7
rsa 2048 bits 0.449728s 0.014178s      2.2     70.5
rsa 4096 bits 2.962890s 0.048354s      0.3     20.7
                  sign    verify    sign/s verify/s
dsa  512 bits 0.012400s 0.015442s     80.6     64.8
dsa 1024 bits 0.035831s 0.044040s     27.9     22.7
dsa 2048 bits 0.119420s 0.149021s      8.4      6.7

Very nice!

Wireless Channel Listing

...because there never seems to be one around when you need it most:

Channel   1 : 2412  Mhz 11bg      Channel  36 : 5180  Mhz 11a
Channel   2 : 2417  Mhz 11bg      Channel  40 : 5200  Mhz 11a
Channel   3 : 2422  Mhz 11bg      Channel  44 : 5220  Mhz 11a
Channel   4 : 2427  Mhz 11bg      Channel  48 : 5240  Mhz 11a
Channel   5 : 2432  Mhz 11bg      Channel  52 : 5260  Mhz 11a
Channel   6 : 2437  Mhz 11bg      Channel  56 : 5280  Mhz 11a
Channel   7 : 2442  Mhz 11bg      Channel  60 : 5300  Mhz 11a
Channel   8 : 2447  Mhz 11bg      Channel  64 : 5320  Mhz 11a
Channel   9 : 2452  Mhz 11bg      Channel 149 : 5745  Mhz 11a
Channel  10 : 2457  Mhz 11bg      Channel 153 : 5765  Mhz 11a
Channel  11 : 2462  Mhz 11bg      Channel 157 : 5785  Mhz 11a
Channel  12 : 2467  Mhz 11bg      Channel 161 : 5805  Mhz 11a
Channel  13 : 2472  Mhz 11bg      Channel 165 : 5825  Mhz 11a

Now, if only the ath card in my Soekriswould associate in 11a mode reliably... finicky little buggers (b/g are NP). Next time I'll be sure to go to the extra effort to acquire ral cards... someone needs to start carrying them.

Gone Indie

At the end of December I left my position with KPMG to concentrate on technical security consulting and my masters degree. This all leads me to announce the creation of a new corporate entity, and my security company:

Strange Research Corporation

There isn't much content up on the site yet as I'm still playing with the layout, but check it out!

Strange Assortments

Ah, the obligatory "it has been too long since I've posted anything" post... I try to approach posting by following the advise of my friend ex-P.F.C. Wintergreen, who usually detests blogs but has relented on this position as of late, and at least keep my posts somewhat oriented towards novel ideas. Sometimes it simply helps to keep writing.

I see that FX is posting at the SABRE Lablog, always interesting to read what he is thinking about or working on.

I don't often find software that is worth paying for outside of music tools and operating systems (donate!) but this is wicked cool diagramming software for OS X: omnigraffle. Go buy a copy and make your life prettier.

Haven't had much time for PDB lately, the whole school + work combination has been crazy busy. I started a project concerned with using a cVu 1000 from the dudes at cpacket to control the bandwidth usage of network flows. I have other more fun ideas for this device... suffice it to say that it is always fun to make networking products earn their rack space.

Porting PDB to OpenBSD Act I Scene II

The need to run Matlab necessitated bringing my PowerBook back from the land of music and sound design... So, with a fresh install of Tiger I now have a box running an OS that implements divert sockets... Getting PDB up and running while my physical layer class works on examples of free space loss (and their arithmetic skills) seems like a great way to make use of the day.

Quick and dirty process to get PDB up and running on OS X:

• Step 0 - clean out bleeding edge cruft

Clean up the build dirs for libcii and libfmt. Build those libs from the Makefiles in their respective directories; the top level make file isn't set up to do it (yet).

• Step 1 - rbconfig.rb is broken by default in Tiger. Fix it.
  

• Step 3 - where, oh where is ruby.h?

I didn't save the output from make, but the gist of it is that with the latest Xcode and the transition to universal binaries our lib path is messed up. Ruby header files are now in universal-darwin8.0 not powerpc-darwin8.0. Just symlink it all:

ln -s /usr/lib/ruby/1.8/universal-darwin8.0/* /usr/lib/ruby/1.8/powerpc-darwin8.0/ 

Now we're ready to get to business with PDB...

The 'pdb' executable is actually a little shell script that has functions for adding/deleting ipfw divert rules and running pdb (nee iledit). I wanted to do a little simple testing with a clear text protocol so I changed the divert rules to accomodate passive FTP:

~/tools/src/pdb-0.0.1.bleeding-edge$sudo ./pdb
==> Adding ipfw divert rules...
00242 divert 4642 tcp from any to any dst-port 21 out
00243 divert 4642 tcp from any 21 to any in
==> Running pdb...
hi pdb-ruby.bundle
hi ip.bundle
(pdb) c
                        45 10 00 38 20 c5 40 00                      E..8..@.
                        40 06 00 00 c0 a8 01 03                      @.......
                        81 80 05 bf c0 60 00 15                      .....`..
                        98 d3 dd f7 82 18 d1 3c                      .......<
                        50 18 ff ff 54 5f 00 00                      P...T_..
                        55 53 45 52 20 61 6e 6f                      USER.ano
                        6e 79 6d 6f 75 73 0d 0a                      nymous..

..SNIP..

(pdb) exit
I am slain!
==> Removing ipfw divert rule...
~/tools/src/pdb-0.0.1.bleeding-edge$

Excellent! More experimenting to come... time to read some code.