When using a settings file that is encoded in something other than UTF-8 (for instance Windows-1252) containing non-ASCII characters, GPG outputs a meaningful error message or detects the encoding and uses it correctly. It should never create an invalid key.
When using gpg --gen-key with a settings file encoded in Windows-1252 containing non-ASCII characters (for instance German Umlauts) in the Name-Real field, GPG will create a key with a Windows-1252-encoded user Id. This is in violation of RFC 4880, section 5.11 which states that the user Id must be encoded in UTF-8.
Tested with GPG4win 3.1.5, GnuPG 2.2.11 and GnuPG 2.0.26 on Windows 10. I suspect this issue also occurs with other distributions and OS.
Steps to reproduce
- Create a Windows-1252 encoded settings file with the following content:
Key-Type: RSA Key-Length: 4096 Subkey-Type: RSA Subkey-Length: 4096 Name-Real: Ümläut Name-Email: uemlaut@localhost Expire-Date: 5y %ask-passphrase %commit
- Create a new key with gpg --batch --gen-key <SETTINGS-FILE>
- If you inspect the public key, you will see that the user Id is encoded in Windows-1252