salted encryption for md5

[Adrian Gherasim]

I'm trying to check a md5 password with Linux shadow file. The Linux password is composed from password and salt.

Here is the shadow entries password: $1$KFcTuUdc$aI4ZxkbM0P/GcBsZuiG22/

The salt is: KFcTuUdc

The encrypt pass is: aI4ZxkbM0P/GcBsZuiG22/

I try some Node JS modules but all are giving a different md5 password from the Linux shadow file.

Thanks in advance

Adrian