Am Thu, 18 Feb 2016 17:37:52 +0000 Gary Palmer <gpalmer_at_freebsd.org> schrieb: > On Thu, Feb 18, 2016 at 06:11:22PM +0100, O. Hartmann wrote: > > Am Thu, 18 Feb 2016 09:29:26 -0700 > > Ian Lepore <ian_at_freebsd.org> schrieb: > > > > > On Thu, 2016-02-18 at 16:29 +0100, O. Hartmann wrote: > > > > On Thu, 18 Feb 2016 14:52:44 +0000 > > > > RW <rwmaillists_at_googlemail.com> wrote: > > > > > > > > > On Thu, 18 Feb 2016 14:16:24 +0100 > > > > > O. Hartmann wrote: > > > > > > > > > > > Hello out there, > > > > > > > > > > > > I run into a problem and digging for a solution didn't work out. > > > > > > > > > > > > Problem: I need a string that reflects the hashed password for the > > > > > > usage with > > > > > > > > > > > > passwd -H 0 > > > > > > > > > > Did you mean -h? > > > > > > > > no, I literally mean -H 0, I explain later ... > > > > > > > > > > > > > > > I think the procedure is using > > > > > > > > > > > > sha512 -s Password > > > > > > > > > > > > and using this output for further processing, but how? > > > > > > > > > > It's not as simple as that, password hashes are usually salted and > > > > > iterated. Salting means that the password is combined with a randomly > > > > > generated string stored in plaintext, which means that the password > > > > > doesn't hash to a fixed string. > > > > > > > > > > I'm not sure exactly what you are trying to do, but crypt(3) may be of > > > > > help. > > > > > > > > I'm now down to a small C routine utilizing crypt(3). But this is not what I > > > > intend to have, since I want to use tools from the FBSD base system. > > > > > > > > I build images of a small appliance in a secure isolated environment via > > > > NanoBSD. I do not want to have passwords in the clear around here, but I also > > > > do not want to type in everytime an image is created, so the idea is to have > > > > passwords prepared as hashes in a local file/in variables. Therefore, I'm > > > > inclined to use the option "-H 0" of the pw(1) command to provide an already > > > > and clean hash (SHA512), which is then stored in /etc/master.passwd. > > > > > > > > It is really funny: passwd or pw take passwords via stdin (-h 0 with pw) and > > > > they "generate" somehow the hashed password and store that in master.password > > > > - but I didn't find any way to pipe out the writing of the password to the > > > > standard output from that piece of software. Why? Security concerns I forgot to > > > > consider? > > > > > > > > I found lots of articles and howtos to use pipes producing the required > > > > password hashes via passwd, chpasswd or pw, but they all have one problem: I > > > > have to provide somehow the cleartext password in an automated environment. > > > > > > > > Maybe there is something missing ... > > > > > > > > oh > > > > > > We use something like this at work (which I don't fully understand, but > > > it works on freebsd 6.x through 10.x at least)... > > > > > > echo ${password} | openssl passwd -1 -stdin -salt VerySalty | \ > > > pw -V ${IMAGE_CHROOT_DIR}/etc useradd -n ${username} -H0 $* > > > > > > I guess for your use you'd capture and save the output of openssl so > > > you could later feed it back to pw when making images. > > > > > > -- Ian > > > > The "openssl passwd -1" refers to MD5 hashes, as I understand the manpage, but I > > require at least sha256. With this solution suggested, I'd have the password still > > stored in cleartext somewhere - if not read -in via read or similar. > > > > If you snip off the openssl portion and substitute "-H0" with "-h0", then this is the > > way I did before - as defined/configured in login.conf (usually in > > ${IMAGE_CHROOT_DIR}/etc) SHA512 will be used as digest algorithm and the password > > seems "salted", prepended by the $6$ characters. > > > > I'd like to have something like > > > > echo ${password} | openssl passwd -sha512 -stdin -salt VerySalty > > > > and store the result in a variable somewhere for use with > > > > echo ${password_salted_sha512_hash} | pw -V ${IMAGE_CHROOT_DIR}/etc usermod -n\ > > ${username} -H 0 > > I presume you want to generate the password manually (to eliminate the > storage of the cleartext password) and then store the hash in a script > somewhere to be reused? How often do you need to generate new hashes? Quite often - weekly and the images are numerous. The problem is that I made in the initial phase mistakes - lack of concentration et cetera and several passwords were then worng and the images wrecked (CD/DVD). > > I'm wondering why you can't have a dummy user that you just change the > password for when you need a new hash and then grab the crypted password > out of /etc/master.passwd Well, this idea has also come to my mind - but the efford would be more (scripts to extract ...) and, on the other hand, it's quite non-academic! I'd like a clean solution. passwd() somehow results in such a hash - but passwd writes its hash into a file, no chance so far to pipe the hash out. As Allen Jude already wrote - OpenBSD does have the desired tool and it seems to me that there is need - in security areas, were OpenBSD has its domain. > > Thanks, > > Gary
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