Description of problem:
Trying to configure CHAP password longer than 255 characters, only the first 255 characters are used for password.

Version-Release number of selected component (if applicable):
targetcli-2.1.fb41-3.el7.noarch

How reproducible:
100%

Steps to Reproduce:
1.Create a password with 256 characters
# export password=`cat /dev/urandom | tr -dc 'a-zA-Z0-9' | head -c 256`
# echo ${#password}
256

2.Create an iSCSI target
# targetcli /iscsi create iqn.2009-10.com.redhat:storage-1

3. Set the CHAP password
# targetcli /iscsi/iqn.2009-10.com.redhat:storage-1/tpg1 set auth password=$password
Parameter password is now 'JlNkQ1xmnhsYCukUIl5Ors8tiLNGnPu6GmUxhhidLvSuEEaZWqctB2rljEEC0xD1MuoqAgYunW33CWF1xncRZ93ns6wGbHKKKph6rPjYPB9mUudQKIHW2wtfYvnktkGKTnOZhjVnc4irBcxMxCLtVBobp9MtOmAee4gfHxDuhuScPKkb2DjoEtUBZ3h0xZ7RkpPqv8JGCK5BgKYo9uibwpGNgcK4ya56tiIEEesF5yGilqit3tfRGUJJBLeWJSz'.

# echo $?
0

4. Check the last character was not set
# echo $password
JlNkQ1xmnhsYCukUIl5Ors8tiLNGnPu6GmUxhhidLvSuEEaZWqctB2rljEEC0xD1MuoqAgYunW33CWF1xncRZ93ns6wGbHKKKph6rPjYPB9mUudQKIHW2wtfYvnktkGKTnOZhjVnc4irBcxMxCLtVBobp9MtOmAee4gfHxDuhuScPKkb2DjoEtUBZ3h0xZ7RkpPqv8JGCK5BgKYo9uibwpGNgcK4ya56tiIEEesF5yGilqit3tfRGUJJBLeWJSze

Expected results:
targetcli should return some error informing the password is too long or provide some warning informing the password will be truncated.




The problem also happens with userid longer than 255.