From: Tony Arcieri <tony.arcieri@...>
Date: 2012-10-29T01:33:58+09:00
Subject: Re: OpenSSL ECDSA public key from private

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On Sun, Oct 28, 2012 at 2:46 AM, Nokan Emiro <uzleepito@gmail.com> wrote:

> I'm sure I made a mistake but for me this script does not work.  The
> problem is that OpenSSL::PKey::EC::Point does not have a #mul
> method in it.
>
> 1.9.3-p194 :001 > require 'openssl'
>  => true
> 1.9.3-p194 :002 > key = OpenSSL::PKey::EC.new 'secp256k1'
>  => #<OpenSSL::PKey::EC:0x00000001cbb960>
> 1.9.3-p194 :003 > OpenSSL::PKey::EC::Point.new(key.group).methods.grep
> /mul/
>  => []
> 1.9.3-p194 :004 >
>
> :(
>

I ran into this same problem. #mul is only available on the absolute latest
builds of Ruby.

You might consider using my red25519 gem instead if you're simply looking
for a signature algorithm and do not specifically need ECDSA:

https://github.com/tarcieri/red25519

You can most certainly generate public keys from private ones using this
gem:

Ed25519::SigningKey.new(private_key).verify_key.to_bytes

-- 
Tony Arcieri

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On Sun, Oct 28, 2012 at 2:46 AM, Nokan Emiro <span dir=3D"ltr">&lt;<a href=
=3D"mailto:uzleepito@gmail.com" target=3D"_blank">uzleepito@gmail.com</a>&g=
t;</span> wrote:=A0<div class=3D"gmail_quote"><blockquote class=3D"gmail_qu=
ote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex=
">

<div><div class=3D"gmail_quote"><div class=3D"im">I&#39;m sure I made a mis=
take but for me this script does not work. =A0The</div><div><div>problem is=
 that=A0OpenSSL::PKey::EC::Point does not have a #mul</div><div>
method in it.</div><div><br></div><div><div>1.9.3-p194 :001 &gt; require &#=
39;openssl&#39;</div><div>=A0=3D&gt; true=A0</div><div>1.9.3-p194 :002 &gt;=
 key =3D OpenSSL::PKey::EC.new &#39;secp256k1&#39;</div><div>=A0=3D&gt; #&l=
t;OpenSSL::PKey::EC:0x00000001cbb960&gt;=A0</div>


<div>1.9.3-p194 :003 &gt; OpenSSL::PKey::EC::Point.new(key.group).methods.g=
rep /mul/</div><div>=A0=3D&gt; []=A0</div><div>1.9.3-p194 :004 &gt;=A0</div=
></div></div><div><br></div><div>:(</div></div></div></blockquote></div><di=
v><br>

</div>I ran into this same problem. #mul is only available on the absolute =
latest builds of Ruby.<br clear=3D"all"><div><br></div><div>You might consi=
der using my red25519 gem instead if you&#39;re simply looking for a signat=
ure algorithm and do not specifically need ECDSA:</div>

<div><br></div><div><a href=3D"https://github.com/tarcieri/red25519">https:=
//github.com/tarcieri/red25519</a></div><div><br></div><div>You can most ce=
rtainly generate public keys from private ones using this gem:</div><div>

<br></div><div>Ed25519::SigningKey.new(private_key).verify_key.to_bytes</di=
v><div><br></div>-- <br>Tony Arcieri<br><br>

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