private static bool IsSubKeyForSigning()

in net/JetBrains.DownloadPgpVerifier/src/PgpSignaturesVerifier.cs [129:152]

• 22 lines of code
• 11 McCabe index (conditional complexity)

    private static bool IsSubKeyForSigning(PgpPublicKey masterPublicKey, PgpPublicKey publicKey, Action<string> onError)
    {
      if (masterPublicKey == null) throw new ArgumentNullException(nameof(masterPublicKey));
      if (publicKey == null) throw new ArgumentNullException(nameof(publicKey));
      if (onError == null) throw new ArgumentNullException(nameof(onError));
      if (!masterPublicKey.IsMasterKey)
        throw new Exception($"Master key is required. KeyID={masterPublicKey.KeyId:X16}");
      if (publicKey.IsMasterKey)
        throw new Exception($"Sub key is required. KeyID={publicKey.KeyId:X16}");

      foreach (PgpSignature signature in publicKey.GetKeySignatures())
        if (signature.SignatureType == PgpSignature.SubkeyBinding)
          if ((signature.GetHashedSubPackets().GetKeyFlags() & KeyFlags.SignData) != 0)
            if (CheckSignatureFormat(signature, onError))
            {
              signature.InitVerify(masterPublicKey);
              if (signature.VerifyCertification(masterPublicKey, publicKey))
                return true;
              onError($"Failed to verify the certification of the signature MasterKeyID={masterPublicKey.KeyId:X16} SubKeyID={publicKey.KeyId:X16}");
            }

      onError($"Incompatible keys MasterKeyID={masterPublicKey.KeyId:X16} SubKeyID={publicKey.KeyId:X16}");
      return false;
    }