MD5 vs. SHA1 hashed passwords in /etc/master.passwd: can we configure SHA1 in /etc/login.conf?

[Poul-Henning Kamp]

In message <495FDC97.4090301 at mail.zedat.fu-berlin.de>, "O. Hartmann" writes:

>MD5 seems to be compromised by potential collision attacks.

No it is not.

Single MD5 invocations with controlled plaintext allow you to
construct appendages to the plaintext, which would result in
identical MD5 hash values.

This does not affect your passwords.

1. If you already know peoples password, why futz with the encryption
   of them ?

2. MD5 password hash is not single invocation, in fact MD5 i iterated
   more than a thousand times in various permutations.  Nobody has
   any idea how to break that, short of brute force.

Poul-Henning

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Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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