Returns -1 in case of error.

For masks like dir1\dir2*\*.ext in non-recursive mode.

Calculate the block size including encryption fields and padding if any.

For masks like dir1\dir2*\file.ext this function sets 'dir1' recursive mask and '*\dir2*\file.ext' filter. Masks without folder wildcards are returned

Fill buffer with random data.

Apply Gauss�Jordan elimination to find inverse of decoder matrix. We have the square NDxND matrix, but we do not store its trivial diagonal "1" rows m

We do not want to cast every signed char to unsigned when passing to isalpha, so we implement the replacement. Shall work for Unicode too. If chars ar