Linux/Unix

Generating a Unique DH (Diffie-Hellman) Group

Posted on by Andy

Due to a recent D(iffie)H(ellman) attack possibility called LogJam on lower paramter lengths like 512 bit and maybe, in short future, 768 bit, here the command to create a real strong parameter of 4096 bit: 

openssl dhparam -out dhparams.pem 4096

 

Please be aware that this key creation can take up to 20 minutes and evern longer depending on your CPU.

Most software (apache, postfix, sendmail, dovecot etc) have config parameters where you can set the Diffie-Hellman group file. The DH algorithm is used to create secure keys when using connections over SSL/TLS.

More information about configuring different servers can be found here.

Failed compilation for VMware HGFS kernel module

Posted on by Andy

Vmware-tools have a kernel module for shared folders. On Ubuntu 14.04 the module compilation fails with something like "alias […] inode.c […] line 28". The fix is quite easy, here are the simple steps: 

cd vmware-tools-distrib/lib/modules/source
tar -xvf vmhgfs.tar
cd vmhgfs-only
vim inode.c
":%s/d_alias/d_u.d_alias/g" (execute vim command inside editor, no quotes)
":wq!" (execute vim command)
cd ..
tar -cvf vmhgfs.tar vmhgfs-only

Now install vmware-tools normally, then shutdown and add a shared folder to your VM. After a new boot you should access your shared folder at /mnt/hgfs

source: vmware communities