Re: Support for 448 bit hash value generation in opnessl.

2012-12-18 Thread Jakob Bohm
On 12/18/2012 8:53 PM, Jeffrey Walton wrote: On Tue, Dec 18, 2012 at 3:24 AM, Matt Caswell (fr...@baggins.org) wrote: On 18 December 2012 05:30, jeetendra gangele wrote: Ok, can you expain me how ec_compute_key work and specially this last argument. Why its need hash value to calculate th

Re: Support for 448 bit hash value generation in opnessl.

2012-12-18 Thread Jeffrey Walton
On Tue, Dec 18, 2012 at 3:24 AM, Matt Caswell (fr...@baggins.org) wrote: > > > On 18 December 2012 05:30, jeetendra gangele wrote: >> >> Ok, >> >> can you expain me how ec_compute_key work and specially this last >> argument. >> Why its need hash value to calculate the secret key. >> I need to ge

Re: Support for 448 bit hash value generation in opnessl.

2012-12-18 Thread jeetendra gangele
Yes I tried 64 bytes hash but I need 56 bytes only as I told. see the below code I am trying with SHA512 but I need only 56 bytes not 64. It looks like ECDH_compute_key trying to copy all 64 bytes into the shared secret buffer?. I want only 56 bytes,is there a way that I can get 56 bytes shared key

Re: Support for 448 bit hash value generation in opnessl.

2012-12-18 Thread Matt Caswell (fr...@baggins.org)
On 18 December 2012 05:30, jeetendra gangele wrote: > Ok, > > can you expain me how ec_compute_key work and specially this last argument. > Why its need hash value to calculate the secret key. > I need to generate the 56 BYtes shred key. > A KDF (Key Derivation Function) is typically used to gen

Re: Support for 448 bit hash value generation in opnessl.

2012-12-17 Thread jeetendra gangele
Ok, can you expain me how ec_compute_key work and specially this last argument. Why its need hash value to calculate the secret key. I need to generate the 56 BYtes shred key. On 18 December 2012 10:32, Jeffrey Walton wrote: > On Mon, Dec 17, 2012 at 11:50 PM, jeetendra gangele > wrote: >> U me

Re: Support for 448 bit hash value generation in opnessl.

2012-12-17 Thread Jeffrey Walton
On Mon, Dec 17, 2012 at 11:50 PM, jeetendra gangele wrote: > U mean to say I can generate 64 bytes and then I can ignore last 8 > bytes? so I will get 56 bytes. > This value then I have to use as secret key for ECDH https://www.google.com/#q=truncated+hash Be careful of ECDH because its anonymous

Re: Support for 448 bit hash value generation in opnessl.

2012-12-17 Thread jeetendra gangele
U mean to say I can generate 64 bytes and then I can ignore last 8 bytes? so I will get 56 bytes. This value then I have to use as secret key for ECDH On 18 December 2012 09:57, Jeffrey Walton wrote: > On Mon, Dec 17, 2012 at 11:16 PM, jeetendra gangele > wrote: >> Hi, >> Do we have support fo

Re: Support for 448 bit hash value generation in opnessl.

2012-12-17 Thread Jeffrey Walton
On Mon, Dec 17, 2012 at 11:16 PM, jeetendra gangele wrote: > Hi, > Do we have support for 448 bit hash value generation in openssl.? > I looked into the header file and I did not find functiobn related to that. > > Actually I need to compute shared key for ecdh and that should be 56 Bytes > long.