When I try to computed shared key with DH_compute_key, I have got error :
error:05066064:Diffie-Hellman routines:COMPUTE_KEY:no private value.
Could you tell me what should I do to fix this problem ?
( I 'll try EVP_PKEY later ).
Thanks.
2011/3/24 ikuzar <razuk...@gmail.com>
> I have to use DH structure ( I have no choice ). So I 'll try
> EVP_PKEY_new() as Dr. Henson said.
> However I 'd like to learn and understand how to verify if DH_generate_key(
> ) has really set pbkey and pvkey.
> ikuzar.
>
>
> 2011/3/24 Mike Mohr <akih...@gmail.com>
>
>> ikuzar,
>>
>> I'm sorry to be blunt, but if you don't understand what I'm saying
>> then you shouldn't be writing code that deals with low-level
>> cryptographic objects/primitives. See the recent revelations from
>> Sony and Nokia for why: even multinational corporations with hundreds
>> of specialist developers can all too easily ship "epic failboat" code.
>> As Dr. Henson has already pointed out you should use the subroutines
>> that OpenSSL provides to you.
>>
>> On Wed, Mar 23, 2011 at 4:50 PM, ikuzar <razuk...@gmail.com> wrote:
>> > I do not understand what you mean.
>> >
>> > 1) I tried to print data's size returned by i2d_DHparams(const_dh,
>> > &dhbuf); without computing private nor public key. I have got 138
>> bytes.
>> > Then I remade the same operation but I had computed private and public
>> key
>> > using DH_generate_key(dh);
>> > and I have still got 138 bytes ...it seems to be odd for me, because I
>> think
>> > dh's size must be greater after computing keys.
>> >
>> > 2) I tried the following check before and after computing keys :
>> > if (dh->priv_key == NULL)
>> > printf("\n1)dh->priv_key is NULL\n");
>> > else
>> > printf("\n1)dh->priv_key is not NULL\n");
>> > Before computing key, I have got priv_key is NULL. After computing,
>> priv_key
>> > is not NULL
>> >
>> > I 'm wondering what happens... could you tell me more about bit counting
>> ? I
>> > do not understand "The private and public keys should be similar in size
>> to
>> > p. "
>> >
>> > Thanks for your help.
>> >
>> >
>> > 2011/3/23 Mike Mohr <akih...@gmail.com>
>> >>
>> >> Try checking the bit count of the structure members. The private and
>> >> public keys should be similar in size to p.
>> >>
>> >> On Mar 23, 2011 10:27 AM, "ikuzar" <razuk...@gmail.com> wrote:
>> >> > Hello,
>> >> > I 'd like to know how to verify that DH private and public key have
>> been
>> >> > generated ?
>> >> > In my DH struct, p and g had been generated with commands line (
>> openssl
>> >> > dhparam... )
>> >> >
>> >> > struct
>> >> > {
>> >> > BIGNUM *p; // prime number (shared)
>> >> > BIGNUM *g; // generator of Z_p (shared)
>> >> > BIGNUM *priv_key; // private DH value x
>> >> > BIGNUM *pub_key; // public DH value g^x
>> >> > // ...
>> >> > };
>> >> > DH
>> >> >
>> >> >
>> >> > Priv_key and pub_key are generated later with DH_generate_key(dh).
>> >> >
>> >> > I would like verify if DH_generate_key( ) has generated the priv_key
>> (
>> >> > an
>> >> > human proof, example by using DHparams_print_fp(fp, dh ); ) I used
>> this
>> >> > function but it did not print private key into file pointed by fp.
>> >> >
>> >> > Thanks for your help.
>> >
>> >
>> ______________________________________________________________________
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>>
>
>
