AdES is mostly an technical standard that specifies how to use existing PKCS and IETF standards to produce eIDAS conforming signature, timestamp or “seal” (ie. timestamped signature) and how that should be mapped onto CMS (CAdES), XML-Signature (XAdES) and PDF (PAdES). How legally binding the result of that process is then depends on things like QSCTs, their LoA used in that and such things. And then there are various carveouts, for example in CZ, you can just generate CSR with ‘openssl req’ get that signed by right CA and produce QESs with that (and assume all the risks inherent in doing that)
> for example in CZ, you can just generate CSR with ‘openssl req’ get that signed by right CA and produce QESs with that (and assume all the risks inherent in doing that)
AFAIK that is not true. In CZ national law, there is also recognized electronic signature (RES, "uznávaný elektronický podpis"), which may be either QES (per eIDAS, "kvalifikovaný elektronický podpis"), or just AdES based on certificate from qualified CAs (per national law, "zaručený elektronický podpis, založený na kvalifikovaném certifikátu").
If you use QSCD to generate CSR and get it signed by right CA, you get QES, but if you use just 'openssl req' to generate CSR and get it signed by right CA, you get RES that is not QES.
The point is that the CA has no way to determine that the CSR was generated by Qualified Device and will just sign it. My view of all the talk about Qualified Devices in eIDAS exists mostly to force QCAs to use normal enrollment process with CSRs instead of their random home-grown processes that result in PKCS#12 file containing private key generated who knows where and who knows how.
