Encryption

David Kwinter david at kwinter.ca
Fri Oct 1 15:50:57 EDT 2004


----- Original Message ----- 
From: "Mark Brownell" <gizmotron at earthlink.net>
To: "How to use Revolution" <use-revolution at lists.runrev.com>
Sent: Friday, October 01, 2004 12:42 PM
Subject: Re: Encryption


>
> On Friday, October 1, 2004, at 12:26 PM, David Kwinter wrote:
>
> > Using bf-ofb with a 41 char key (328bits) with 328bits specified for
> > encryption, the source does not come back properly after decryption,
> > instead it's garbage binary data.
> >
> > If I use "blowfish" instead of "bf-ofb", everything works fine up
> > until 320bits, higher than that I get the error
> > "error:06065064:digital envelope routines:EVP_DecryptFinal:bad >
decrypt"
> >
> > Is anyone having better luck with this?
>
>
> A little background on Blowfish. You might need to make the char keys
> in increments of four char steps. Four chars is 32 bit, eight chars is
> 64 bit, twelve chars is 96 bit level encryption for instance. Some
> algorithms need to clean up the number of chars before they are used as
> a key. So 41 chars might be causing a problem only because it doesn't
> conform to a 32 bit block size.
>
> What happens with a 56 char key?
>
> Mark
>

56 char is what I tried first, with "bf-ofb" I get garbage binary with
"blowfish" I get the error: "error:06065064:digital envelope
routines:EVP_DecryptFinal:bad > decrypt"

40 chars/320bits seems to be the breakpoint



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