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

[Dominik Csapak]

On 4/9/25 14:58, Shannon Sterz wrote:
> 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.

IIUC the PRIV_PERMISSIONS_MODIFY is only a single bit, so partial/not partial makes
no difference in this diff here.

but yeah sure, if we have multiple privileges that would all allow setting
ACL individually, we would have to match with `partial = true`

> 
>> +        )
>> +        .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 => {
>> ---
>