> From: owner-openssl-us...@openssl.org On Behalf Of
muell...@mathematik.hu-berlin.de
> Sent: Monday, 13 September, 2010 05:08
> > md5(admin [NO NEWLINE])= 21232f297a57a5a743894a0e4a801fc3
> The next step is to understand the insertion of salt. I tried to
> understand 'enc.c' and 'evp_key.c', for key derivation EVP_BytesToKey()
> is called. I am not familiar with things like MDcontexts; BIOs etc,
man 3ssl EVP_MD_CTX_init # or wherever it is on your system
BIOs are used extensively in most of apps/*, but not relevant
to this key derivation which is entirely in EVP_BytesToKey().
> so i don't understand it very well. But according to its documentation
> it computes
>
> D_0 = {}
> D_i = hash(d_{i-1}||data||salt)
>
> After that the key and iv are taken from D_1, D_2, ...
> For DES it would be enough to generate D_1.
Yes. (Precisely because classic-DES is only 56-bit key
it is now practical to bruteforce, and hence insecure
for most use. I assume you will change later.)
> data = 'admin'
> As salt i use '0000000000000000', so
> 'Salted__0000000000000000' is passed
> to EVP_BytesToKey - Anyway i cant reproduce
>
> > openssl enc -des -k 'admin' -P -S 0000000000000000
>
> salt=0000000000000000
> key=752B559CFABA36F6
> iv =9B6A524533353200
>
> by hand. A Similar problem with
>
Note that the value for -S (and -K(uppercase) and -iv)
is hex, as is the output from -p/P (and dgst).
~/CSdev/hack $ od -xc t
0000000 6164 6d69 6e00 0000 0000 0000 0000
a d m i n \0 \0 \0 \0 \0 \0 \0 \0
0000015
~/CSdev/hack $ openssl <t md5 -binary |od -x
0000000 752b 559c faba 36f6 9b6a 5245 3335 3200
0000020
> openssl enc -blowfish -k 'admin' -P -nosalt
> key=21232F297A57A5A743894A0E4A801FC3 = md5(admin)
> iv =7BED69E4F5F533BE != md5(md5(admin)||admin)..
>
> can someone give me some hints..
>
~/CSdev/hack $ od -xc t0
0000000 6164 6d69 6e00
a d m i n
0000005
~/CSdev/hack $ openssl <t0 md5 -binary >t1; od -x t1
0000000 2123 2f29 7a57 a5a7 4389 4a0e 4a80 1fc3
0000020
~/CSdev/hack $ cat t1 t0 | openssl md5 -binary | od -x
0000000 7bed 69e4 f5f5 33be e8a4 19b5 7be5 f229
0000020
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