Error on create duplicate key

[trishankatdatadog]

Prevent overwrite when creating key with same name as an existing key.

Signed-off-by: Trishank Karthik Kuppusamy trishank.kuppusamy@datadoghq.com

[LeSuisse]

Hi,

Thanks for the contribution (and again sorry for the delay in my responses 🙁 )!

When I designed this endpoint I voluntarily missed this check because I wanted to be consistent with built-in engines of Vault.
Engines that use a named key do not protect against the overwriting of a specific key at least not in a explicit manner. For example the TOTP engine behave like this one and just overwrite existing key. The transit engine has a more subtle behavior and does not overwrite the key but does throw an error.
I'm however fine with the proposed change since overwriting a key can have disastrous consequences and I prefer to have an explicit error than something silently doing nothing.

[LeSuisse]

This will be released as a major version due to the behavior change of the creation endpoint.

[trishankatdatadog]

When I designed this endpoint I voluntarily missed this check because I wanted to be consistent with built-in engines of Vault.
Engines that use a named key do not protect against the overwriting of a specific key at least not in a explicit manner. For example the TOTP engine behave like this one and just overwrite existing key. The transit engine has a more subtle behavior and does not overwrite the key but does throw an error.
I'm however fine with the proposed change since overwriting a key can have disastrous consequences and I prefer to have an explicit error than something silently doing nothing.

Thanks for merging this!

From my tests, Transit SE does not overwrite an existing key or throw an error, but it does return a warning. I agree that it's better to thrown an explicit error than a "silent" warning that can be ignored.