On Dec 23, 8:08 am, Mouse <[email protected]> wrote: > Rijndael specification allows 32-byte block size (AES standard doesn't), > don't know about Rijndael Crypto++ implementation (since in general this > block size is supported by the library, see no reason why not). Indeed (I had to go look at their original paper). From cs.ucsb.edu/ ~koc/cs178/docs/rijndael.pdf: "Rijndael is an iterated block cipher with a variable block length and a variable key length. The block length and the key length can be independently specified to 128, 192 or 256 bits."
> ... > To the Original Poster: you can't do what you want with AES, period. If you > can't reconfigure that server to use a standard algorithm - you're stuck > with Rijndael, which is supported by Crypto ++. Jamaal might also be able to provide an appropriate Rijndael_Info (http://www.cryptopp.com/docs/ref/rijndael_8h_source.html). I have never attempted it, and don't know if it works (or would work). Wei would probably be the best person to answer short of an implementation trial. Jeff > > On Dec 22, 9:02 pm, Jamaal Scarlett <[email protected]> wrote: > > > I wrote a test program and the output for the mcrypt function > > > : mcrypt_module_get_algo_block_size(MCRYPT_RIJNDAEL_256, NULL) is 32. > > The > > > key lengths from all three libraries is 32. > > No. The key length is 32 byte in the case of AES-256. Its 24 bytes > > with AES-192, and 16 bytes with AES-128. The block size is always 16 > > bytes. csrc.nist.gov/publications/fips/fips197/fips-197.pdf. > > > Rijndael may allow for a 32 byte block size. I don't know about > > additional configurations because I don't use it in non-NIST > > configurations. > > > mcrypt has a unique feedback size, if I recall correctly. It has had > > interop problems since the time I can remember. > >http://www.google.com/#q=cryptopp+mcryptt+feedback+size. > > > Jeff > > > On Saturday, December 22, 2012 8:47:15 PM UTC-5, Mouse wrote: > > > > > The simple answer for AES is you can't. AES allows three key lengths > > (128, > > > > 192, 256 bits), but only one block size (128 bits). AES prototype > > Rijndael > > > > allowed three block sizes as well. > > > > > Perhaps by Rijndael-256 they meant only the key length? In that case I > > > > would check the encryption mode, padding, etc. match what that server > > is > > > > set up with. > > > > -- > > > > Regards, > > > > Mouse > > > > On Dec 22, 2012 8:30 PM, "Jamaal Scarlett" <[email protected] > > <javascript:>> > > > > wrote: > > > > >> I need to use AES, the server I am communicating with is using > > > >> mcrypt with the encryption mode set to RIJNDAEL_256. From what I have > > > >> found online, this is a non-standard algorithm. I have tried both > > crypto++ > > > >> and OpenSSL's crypto library and while their encrypted outputs match, > > I > > > >> cannot get either to match the output from mcrypt. I would use > > mcrypt, but > > > >> there is a memory leak in the init function of the version I am > > > >> using(2.5.7) and I am unable to find the lib(libmcrypt.lib) file for > > any > > > >> more recent version of the mcrypt library. > > > > >> Thanks for the help, > > > >> Jamaal > > > > >> On Saturday, December 22, 2012 4:05:32 PM UTC-5, Jeffrey Walton wrote: > > > > >>> On Dec 22, 12:27 pm, Jamaal Scarlett <[email protected]> > > > >>> wrote: > > > >>> > Thank you for the reply. Upon further reading, it looks like the > > 256 > > > >>> in > > > >>> > mcrypts RIJNDAEL_256 refers to the block cipher size. Does > > cryptopp > > > >>> aes > > > >>> > support a 32-bit block cipher size? > > > >>> No, AES is a 16 byte block size. SHACAL2 has a larger block size if > > > >>> you need it. > > > > >>> I believe Zooko (correct me here) needed a cipher with a larger block > > > >>> size and used SHACAL2 for Tahoe-LFS (http://en.wikipedia.org/wiki/ > > > >>> Tahoe-LAFS <http://en.wikipedia.org/wiki/Tahoe-LAFS>). > > > > >>> Jeff > > > > >>> > On Saturday, December 22, 2012 4:11:58 AM UTC-5, Jeffrey Walton > > wrote: > > > > >>> > > On Dec 22, 2:21 am, Jamaal Scarlett <[email protected]> > > > >>> wrote: > > > >>> > > > Is it possible to change key lengths. On the wiki it states > > that > > > >>> > > 16,24&32 byte keys are supported in aes but I cannot find any > > > >>> documentation > > > >>> > > on changing itbftomvthe default of 16. I am attempting to > > > >>> encrypt/decrypt > > > >>> > > data to communicate with a server using mcrypt rijndael 256, > > > >>> however there > > > >>> > > is a memory leak in the version of mcrypt we are using. Is 256 > > bit > > > >>> > > supported? > > > > >>> > > Yes. All relevant objects take a key and key size. See, for > > example, > > > >>> > >http://www.cryptopp.com/wiki/**CBC_mode< > >http://www.cryptopp.com/wiki/CBC_mode>. > > > > >> -- > > > >> You received this message because you are subscribed to the "Crypto++ > > > >> Users" Google Group. > > > >> To unsubscribe, send an email to [email protected] > > <javascript:> > > > >> . > > > >> More information about Crypto++ and this group is available at > > > >>http://www.cryptopp.com. > > > -- > > You received this message because you are subscribed to the "Crypto++ > > Users" Google Group. > > To unsubscribe, send an email to > > [email protected]. > > More information about Crypto++ and this group is available at > >http://www.cryptopp.com. -- You received this message because you are subscribed to the "Crypto++ Users" Google Group. To unsubscribe, send an email to [email protected]. More information about Crypto++ and this group is available at http://www.cryptopp.com.
