PKA - ecdsa curve support

[Hedley]

The sample code uses p256v1 (which seems to actually be p256r1). This curve works well.

I Got PKA to sign correctly using p256k1 with some minor curve updates.

I​ am having trouble setting up p224r1. Has anyone got curves other that p256 to work?

T​nx

H​edley

[Hedley]

Fixed it. The hash normalization for 224 was wrong. The padding in my case needed to be in the upper words before the unroll into pka ram.

  Hash : SHA256_Hash :=

   (16#00#, 16#00#, 16#00#, 16#00#, 16#24#, 16#f0#, 16#37#, 16#06#,

   16#1b#, 16#2b#, 16#3b#, 16#5e#, 16#ba#, 16#8c#, 16#d4#, 16#97#,

   16#36#, 16#ff#, 16#25#, 16#1f#, 16#f0#, 16#11#, 16#63#, 16#5b#,

   16#c3#, 16#c8#, 16#49#, 16#63#, 16#b5#, 16#39#, 16#4f#, 16#f2#);

secp224r1 works fine. I am sure the others will also.

[Hedley]

All these curves are working:

  Test ("secp521r1", 521, H);

  Test ("secp384r1", 384, H);

  Test ("secp256r1", 256, H);

  Test ("secp256k1", 256, H);

  Test ("secp128r1", 128, H);

  Test ("secp112r1", 112, H);

  Test ("secp112r2", 112, H);

  Test ("nistp521", 521, H);

  Test ("nistp384", 384, H);

  Test ("nistp256", 256, H);

  Test ("nistp224", 224, H);

  Test ("nistp192", 192, H);

  Test ("brainpool256r1", 256, H);

  Test ("brainpool256t1", 256, H);

  Test ("brainpool384r1", 384, H);

  Test ("brainpool384t1", 384, H);

This is via an Ada generic:

package body Curve is

  procedure Test (Name : String; NB : UInt32; H : ECDSA_HashStr)

  is

   package EC is new STM32.PKA (Curve_Name => Name, Num_Bits => NB);

   use EC;

   Result   : Boolean;

   PrivateKey : ECDSA_KeyStr    := Make_Random_Group_String (NClamp => True);

   PublicKey : ECDSA_PublicKeyStr := Make_Public_Key_String (PrivateKey);

   K     : ECDSA_RandStr   := Make_Random_Group_String;

   Sig    : ECDSA_SignatureStr;

  begin

   Enable_Pka;

   Result := ECDSA_Sign (PrivateKey, H, K, Sig);

   Result := ECDSA_Valid (PublicKey, H, Sig);

   if not Result then

     raise Program_Error with "curve fail";

   end if;

  end Test;

end Curve;

Code is on github:

https://github.com/morbos/STM32/tree/master/L/L562/pka_gen