Bug 433582

Description of problem:

New bug for performance problem mentioned in
https://bugzilla.redhat.com/show_bug.cgi?id=418481

Current F8 on AMD64.  mcrypt takes impossibly long times on file much greater
than 10MB.  Decryption is fine, but encryption seems to be severely non-linear
in size of file.


Version-Release number of selected component (if applicable):

mcrypt-2.6.7-1.fc8
libmcrypt-2.5.8-4.fc8


How reproducible:

Completely.

Steps to Reproduce:

yes |head -c 1000000 >y6
yes |head -c 10000000 >y7
yes |head -c 100000000 >y8 

for i in y? ; do time mcrypt -k x <$i |wc -c; done

Warning: It is insecure to specify keywords in the command line
Stdin was encrypted.
1000051

real    0m0.226s
user    0m0.182s
sys     0m0.044s
Warning: It is insecure to specify keywords in the command line
Stdin was encrypted.
10000051

real    0m5.694s
user    0m3.368s
sys     0m2.235s
Warning: It is insecure to specify keywords in the command line

Note that the 100MB file y8 is still going after many minutes.

Compare the same with mcrypt-2.6.4-3.fc8:

Warning: It is insecure to specify keywords in the command line
1000109
Stdin was encrypted.

real    0m0.142s
user    0m0.133s
sys     0m0.007s
Warning: It is insecure to specify keywords in the command line
10000109
Stdin was encrypted.

real    0m0.985s
user    0m0.954s
sys     0m0.025s
Warning: It is insecure to specify keywords in the command line
100000109
Stdin was encrypted.

real    0m6.154s
user    0m5.868s
sys     0m0.152s

Much faster, and the 100MB file is successfully encrypted.
  
Actual results:

Doesn't work for large files.

Expected results:

Works for large files.

Additional info: