Messages in this thread | | | Date | Mon, 11 Apr 2005 15:08:29 +0200 | From | Andreas Steinmetz <> | Subject | Re: [PATCH encrypted swsusp 1/3] core functionality |
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folkert@vanheusden.com wrote: >>>The following patch adds the core functionality for the encrypted >>>suspend image. >> >>[Please inline patches, it makes it easier to comment on them.]
Aiyeeh - good ole Mozilla tends to reformat things when inlining...
>>You seem to reuse same key/iv for all the blocks. I'm no crypto >>expert, but I think that is seriously wrong... You probably should use >>block number as a IV or something like that. > > > Or use a feedback loop: xor your data with the outcome of the previous > round. And for the initial block use 0x00...00 for 'previous block'- > value.
I'm already using cipher block chaining, look for CRYPTO_TFM_MODE_CBC in swsusp.c. You may want to have a look at cbc_process in crypto/cipher.c. Thus using the same key is ok. The only known drawback is a watermarking "attack" but this can only used to look for the existence of specially crafted files which are not stored on disk during software suspend.
I should, however, use crypto_cipher_en/decrypt instead of crypto_cipher_en/decrypt_iv as I actually wanted to use the iv in the tfm I did set up with crypto_cipher_set_iv instead of the local copy.
Going to fix that. -- Andreas Steinmetz SPAMmers use robotrap@domdv.de - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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