5 ms·

> because /etc/passwd is world-readable by design for some arcane reason that I can’t find on Google It is pretty comical when people who do not know basics of

> because /etc/passwd is world-readable by design for some arcane reason that I can’t find on Google It is pretty comical when people who do not know basics of how the system permissions work wax about authentication and authorization used by the same systems.

lmilcin 5y ago
Especially when it is not an arcane reason at all. There was a time when it was considered ok to have the salted and MD5-hashed password available to all users. Then people learned to bruteforce the password and so the hash itself was moved to shadow file but passwd was left because a lot of platform software and scripts depended on it. This may shock people nowadays but back then this was fine. I remember having to explain to the users (and sometimes loosing) the need to have a password at all.
- notyourday 5y ago
  Eh, no, it is world readable because even though programs that manipulate/read hashes are privileged, programs that map <uid>:<gid>:<name> are not. This is still the same. If you want to be able to use "ls" as a non-privileged user and see names, you need to be able to access /etc/passwd.
  - lmilcin 5y ago
    So... what did I write? To quote: "but passwd was left because a lot of platform software and scripts depended on it."
    - notyourday 5y ago
      because it is affecting libc and glibc, not the platform software or scripts depending on it.
- mixmastamyk 5y ago
  A different world. The confusion rests on the name of the file I think. If it were named "accounts" (closer to its use) people wouldn't be too surprised it was readable. Then shadow could have been named "passwords."
- dredmorbius 5y ago
  I've ... had that argument, and only very barely succeeded in prevailing, within single-digit years. With a user who's lost multiple accounts to weak passwords. Or should I say, the same weak password. Which they still use in some contexts.... I'm of the opinion that allowing users free choice in passwords is no longer viable. At a bare minimum reuse of any known-compromised password must be rejected.
- not2b 5y ago
  RMS famously campaigned against passwords in his early pre-GNU days at MIT (though I'd say his perspective was specific to the computing environment then; it was more of a matter of how a small group of hackers should cooperate to use an expensive machine, he wanted everyone to have access to everything).

lmilcin 5y ago

Especially when it is not an arcane reason at all. There was a time when it was considered ok to have the salted and MD5-hashed password available to all users. Then people learned to bruteforce the password and so the hash itself was moved to shadow file but passwd was left because a lot of platform software and scripts depended on it. This may shock people nowadays but back then this was fine. I remember having to explain to the users (and sometimes loosing) the need to have a password at all.

notyourday 5y ago
Eh, no, it is world readable because even though programs that manipulate/read hashes are privileged, programs that map <uid>:<gid>:<name> are not. This is still the same. If you want to be able to use "ls" as a non-privileged user and see names, you need to be able to access /etc/passwd.
- lmilcin 5y ago
  So... what did I write? To quote: "but passwd was left because a lot of platform software and scripts depended on it."
  - notyourday 5y ago
    because it is affecting libc and glibc, not the platform software or scripts depending on it.
mixmastamyk 5y ago
A different world. The confusion rests on the name of the file I think. If it were named "accounts" (closer to its use) people wouldn't be too surprised it was readable. Then shadow could have been named "passwords."
dredmorbius 5y ago
I've ... had that argument, and only very barely succeeded in prevailing, within single-digit years. With a user who's lost multiple accounts to weak passwords. Or should I say, the same weak password. Which they still use in some contexts.... I'm of the opinion that allowing users free choice in passwords is no longer viable. At a bare minimum reuse of any known-compromised password must be rejected.
not2b 5y ago
RMS famously campaigned against passwords in his early pre-GNU days at MIT (though I'd say his perspective was specific to the computing environment then; it was more of a matter of how a small group of hackers should cooperate to use an expensive machine, he wanted everyone to have access to everything).