Signing with TECCEncSign and ECCType cc25519;

VCL TMS Cryptography Pack
1

Hello!

I have an issues with signing ebay requests (EdDSA). The Signing result what i get does not match with the correct signatur.

Here is my example code:

ecc:= TECCEncSign.Create;
try
  ecc.ECCType      := cc25519;
  ecc.OutputFormat := base64;
  ecc.Unicode      := NoUni;
  ecc.NaCl         := naclNo;
  ecc.PrivateKey   := 'n4Ni-HpISpVObnQMW0wOhCKROaIKqKtW_2ZYb2p9KcU';
  ecc.PublicKey    := 'JrQLj5P_89iXES9-vFgrIy29clF9CC_oPPsw3c5D0bs';

  sSignatur        := ecc.Sign(sSignaturBase);
finally
  ecc.Free;
end;

sSignaturBase is

"content-digest": sha-256=:X48E9qOokqqrvdts8nOJRJN3OWDUoyWxBf7kbu9DBPE=:
"x-ebay-signature-key": eyJ6aXAiOiJERUYiLCJlbmMiOiJBMjU2R0NNIiwidGFnIjoiSXh2dVRMb0FLS0hlS0Zoa3BxQ05CUSIsImFsZyI6IkEyNTZHQ01LVyIsIml2IjoiaFd3YjNoczk2QzEyOTNucCJ9.2o02pR9SoTF4g_5qRXZm6tF4H52TarilIAKxoVUqjd8.3qaF0KJN-rFHHm_P.AMUAe9PPduew09mANIZ-O_68CCuv6EIx096rm9WyLZnYz5N1WFDQ3jP0RBkbaOtQZHImMSPXIHVaB96RWshLuJsUgCKmTAwkPVCZv3zhLxZVxMXtPUuJ-ppVmPIv0NzznWCOU5Kvb9Xux7ZtnlvLXgwOFEix-BaWNomUAazbsrUCbrp514GIea3butbyxXLNi6R9TJUNh8V2uan-optT1MMyS7eMQnVGL5rYBULk.9K5ucUqAu0DqkkhgubsHHw
"@method": POST
"@path": /verifysignature
"@authority": localhost:8080
"@signature-params": ("content-digest" "x-ebay-signature-key" "@method" "@path" "@authority");created=1658440308

The result of signing (sSignatur) is:
09sn6z7M9hk2pWiGnVCcCYBVlhWrzh6o1vk1eRilAKhC7M/XlvDV26cF1SDX4dOE0CETOD05j03GSgYJBsOAJg==

The correct signatur is:
ZMUpAejnqrt6POSx02ltx3cT9YODV2r+Cem/BKOagDSfztKOtCsjP/MxZqmY+FVJ3/8E4BL76T9Fjty8oJnsAw==

Why doesn't the signatur match?

Best regards

Stefan Lederer