occasional crashes

[2011]

Hi,

First of all, I want to thank you for this program. I recently finished a paper for school that required the creation of over two dozen collisions.

On a few (maybe three) of those, the program simply died at some point. It appears that the program did not create workdirn/paths10_0of1.bin.gz and workdirn/paths11_0of1.bin.gz

This led to the following message in workdirn/connect.log:

Connect MD5 differential paths
Copyright (C) 2009 Marc Stevens
http://homepages.cwi.nl/~stevens/

delta_m[11] = [!31!]
Loading workdir2/paths16_0of1.bin.gz...done: 500000.
Loading workdir2/paths11_0of1.bin.gz...failed.
Best path: totcompl=-1000 tottunnel=0, totcond=1048576
Verified: 0 bad out of 0
Runtime: 14.4187
Caught exception!!:
No lower differential paths loaded!

I have no idea why this happened, but I have saved the entire output directory (about 350 MB compressed) of one of the failures, including the failed workdirs (which I renamed), in case you need any information from them.

Thanks again.

[cr-marcstevens]

Thanks for raising the issue,
can you send the accompanying workdirn/lower.log that failed?

[2011]

I don't have any such file even in the successful workdirn directories.

The directory listing of a "good" workdirn:

$ ls -GRgl .
.:
total 31984
-rw------- 1    52057 2019-09-15 08:09:45 backward.log
drwx------ 2      460 2019-09-15 08:51:42 connect/
-rw------- 1    57262 2019-09-15 08:11:47 connect.log
-rw------- 1    12426 2019-09-15 08:08:01 forward.log
-rw------- 1      148 2019-09-15 08:03:23 lowerpath.bin.gz
-rw------- 1      132 2019-09-15 08:03:23 md5diffpathbackward.cfg
-rw------- 1       70 2019-09-15 08:03:23 md5diffpathconnect.cfg
-rw------- 1      325 2019-09-15 08:03:23 md5diffpathforward.cfg
-rw------- 1       40 2019-09-15 08:03:23 md5diffpathhelper.cfg
-rw------- 1 17067243 2019-09-15 08:07:31 paths10_0of1.bin.gz
-rw------- 1  4846035 2019-09-15 08:08:01 paths11_0of1.bin.gz
-rw------- 1  8363498 2019-09-15 08:09:44 paths16_0of1.bin.gz
-rw------- 1   194979 2019-09-15 08:08:27 paths20_0of1.bin.gz
-rw------- 1  1226841 2019-09-15 08:08:23 paths21_0of1.bin.gz
-rw------- 1   887044 2019-09-15 08:08:05 paths30_0of1.bin.gz
-rw------- 1     3072 2019-09-15 08:03:23 start.log
-rw------- 1       85 2019-09-15 08:03:23 upperpath.bin.gz

./connect:
total 124
-rw------- 1   437 2019-09-15 08:11:43 bestpath.bin.gz
-rw------- 1   437 2019-09-15 08:11:43 bestpath_old.bin.gz
-rw------- 1   437 2019-09-15 08:10:15 bestpath_t33_c569.bin.gz
-rw------- 1   438 2019-09-15 08:10:15 bestpath_t33_c582.bin.gz
-rw------- 1   436 2019-09-15 08:10:15 bestpath_t34_c566.bin.gz
-rw------- 1   436 2019-09-15 08:10:17 bestpath_t35_c565.bin.gz
-rw------- 1   439 2019-09-15 08:10:17 bestpath_t35_c566.bin.gz
-rw------- 1   437 2019-09-15 08:10:56 bestpath_t36_c559.bin.gz
-rw------- 1   435 2019-09-15 08:10:55 bestpath_t36_c560.bin.gz
-rw------- 1   436 2019-09-15 08:10:53 bestpath_t36_c562.bin.gz
-rw------- 1   439 2019-09-15 08:10:53 bestpath_t36_c563.bin.gz
-rw------- 1   437 2019-09-15 08:10:21 bestpath_t36_c565.bin.gz
-rw------- 1   436 2019-09-15 08:10:57 bestpath_t37_c557.bin.gz
-rw------- 1   439 2019-09-15 08:10:57 bestpath_t37_c558.bin.gz
-rw------- 1   437 2019-09-15 08:10:56 bestpath_t37_c559.bin.gz
-rw------- 1   437 2019-09-15 08:11:43 bestpath_t38_c555.bin.gz
-rw------- 1   437 2019-09-15 08:11:43 bestpath_t38_c556.bin.gz
-rw------- 1   438 2019-09-15 08:11:42 bestpath_t38_c557.bin.gz
-rw------- 1   501 2019-09-15 08:11:47 bestpaths.bin.gz
-rw------- 1   441 2019-09-15 08:11:43 bestpaths_old.bin.gz
-rw------- 1 42161 2019-09-15 12:26:46 collfind.log

And one of the failures:

$ ls -GRgl .
.:
total 10036
-rw------- 1   52044 2019-09-15 13:19:42 backward.log
drwx------ 2      60 2019-09-15 13:19:57 connect/
-rw------- 1     372 2019-09-15 13:19:57 connect.log
-rw------- 1     815 2019-09-15 13:17:23 forward.log
-rw------- 1     131 2019-09-15 13:17:16 lowerpath.bin.gz
-rw------- 1     132 2019-09-15 13:17:16 md5diffpathbackward.cfg
-rw------- 1      70 2019-09-15 13:17:16 md5diffpathconnect.cfg
-rw------- 1     321 2019-09-15 13:17:16 md5diffpathforward.cfg
-rw------- 1      40 2019-09-15 13:17:16 md5diffpathhelper.cfg
-rw------- 1 8353693 2019-09-15 13:19:42 paths16_0of1.bin.gz
-rw------- 1  189228 2019-09-15 13:17:47 paths20_0of1.bin.gz
-rw------- 1  769441 2019-09-15 13:17:43 paths21_0of1.bin.gz
-rw------- 1  866944 2019-09-15 13:17:27 paths30_0of1.bin.gz
-rw------- 1    3011 2019-09-15 13:17:16 start.log
-rw------- 1      85 2019-09-15 13:17:16 upperpath.bin.gz

./connect:
total 4
-rw------- 1 188 2019-09-15 13:19:58 collfind.log

[cr-marcstevens]

Ah, sorry I mixed up names, it should be forward.log

[2011]

No problem. I can just include that here due to its small size.

Extend MD5 differential paths forward
Copyright (C) 2009 Marc Stevens
http://homepages.cwi.nl/~stevens/

delta_m[11] = [!31!]
Loading workdir2/lowerpath.bin.gz...done: 1.
Estimating maxcond for upper bound 8000000 (=2000000 * 4)...
t=1:  0%   10   20   30   40   50   60   70   80   90   100%
      |----|----|----|----|----|----|----|----|----|----|
e     ***************************************************
Found maxcond = 2176
t=1:  0%   10   20   30   40   50   60   70   80   90   100%
      |----|----|----|----|----|----|----|----|----|----|
      ***************************************************
Autobalance parameters: maxcond=2176
Verified: 1048576 bad out of 1048576
Autobalance parameters: maxcond=2176
Verified: 0 bad out of 0
Runtime: 7.01919
Caught exception!!:
No valid differential paths found!

[cr-marcstevens]

Ah, that is a surprising failure that I haven't seen before.
Unfortunately, this is not a failure of the programs,
but just unlikely with the prefix.
This can happen and you just have to make a small change and try a different prefix.