[pdm-devel] [PATCH proxmox 2/4] access-control: add acl api feature

[Shannon Sterz]

On Wed Apr 9, 2025 at 1:39 PM CEST, Dominik Csapak wrote:
> On 4/9/25 13:01, Dietmar Maurer wrote:
>>
>>> +/// Get ACL entries, can be filter by path.
>>> +pub fn read_acl(
>>> +    path: Option<String>,
>>> +    exact: bool,
>>> +    rpcenv: &mut dyn RpcEnvironment,
>>> +) -> Result<Vec<AclListItem>, Error> {
>>> +    let auth_id = rpcenv
>>> +        .get_auth_id()
>>> +        .ok_or_else(|| format_err!("endpoint called without an auth id"))?
>>> +        .parse()?;
>>> +
>>> +    let top_level_privs = CachedUserInfo::new()?.lookup_privs(&auth_id, &["access", "acl"]);
>>> +
>>> +    let filter = if top_level_privs & access_conf().acl_audit_privileges() == 0 {
>>> +        Some(auth_id)
>>> +    } else {
>>> +        None
>>> +    };
>>
>> As discussed offline, maybe we can use CachedUserInfo::check_privs here?
>>
>>
>
> maybe something like this for the update case (untested, please verify before using this!):
> (the diff is for pbs, where the code was copied from)
>
> this also includes a reformatted check for the token,non-token, same user checks
> that are IMHO more readable than what we currently have
> with the match, i think it's much more obvious that all cases are handled
>
> ---
>       let user_info = CachedUserInfo::new()?;
>
> -    let top_level_privs = user_info.lookup_privs(&current_auth_id, &["access", "acl"]);
> -    if top_level_privs & PRIV_PERMISSIONS_MODIFY == 0 {
> +    let has_modify_permission = user_info
> +        .check_privs(
> +            &current_auth_id,
> +            &["access", "acl"],
> +            PRIV_PERMISSIONS_MODIFY,
> +            false,

the false here means that partial matches are discounted. i'm not sure
this is correct as at least in pbs and pdm, we do use a partial check as
that is equivalent to the check i ported over.

imo, we'd need to discuss what the proper semantics are here and at
least up until now, we decided for partial semantics.

> +        )
> +        .is_ok();
> +
> +    if !has_modify_permission {
>           if group.is_some() {
>               bail!("Unprivileged users are not allowed to create group ACL item.");
>           }
>
>           match &auth_id {
>               Some(auth_id) => {
> -                if current_auth_id.is_token() {
> -                    bail!("Unprivileged API tokens can't set ACL items.");
> -                } else if !auth_id.is_token() {
> -                    bail!("Unprivileged users can only set ACL items for API tokens.");
> -                } else if auth_id.user() != current_auth_id.user() {
> -                    bail!("Unprivileged users can only set ACL items for their own API tokens.");
> +                let same_user = auth_id.user() == current_auth_id.user();
> +                match (current_auth_id.is_token(), auth_id.is_token(), same_user) {
> +                    (true, _, _) => bail!("Unprivileged API tokens can't set ACL items."),
> +                    (false, false, _) => {
> +                        bail!("Unprivileged users can only set ACL items for API tokens.")
> +                    }
> +                    (false, true, true) => {
> +                        // users are always allowed to modify ACLs for their own tokens
> +                    }
> +                    (false, true, false) => {
> +                        bail!("Unprivileged users can only set ACL items for their own API tokens.")
> +                    }
>                   }
>               }
>               None => {
> ---