api: access: add update support for built-in PAM realm

For the built-in PAM authentication realm, the comment and whether it
should be the default login realm can be updated. Add the required API
plumbing for it.

Signed-off-by: Christoph Heiss <c.heiss@proxmox.com>
Reviewed-by: Lukas Wagner <l.wagner@proxmox.com>
Tested-by: Lukas Wagner <l.wagner@proxmox.com>

src/api2/config/access/mod.rs

@@ -5,10 +5,12 @@ use proxmox_sortable_macro::sortable;
 pub mod ad;
 pub mod ldap;
 pub mod openid;
+pub mod pam;
 pub mod tfa;
 
 #[sortable]
 const SUBDIRS: SubdirMap = &sorted!([
+    ("pam", &pam::ROUTER),
     ("ad", &ad::ROUTER),
     ("ldap", &ldap::ROUTER),
     ("openid", &openid::ROUTER),

src/api2/config/access/pam.rs

@@ -0,0 +1,130 @@
+use ::serde::{Deserialize, Serialize};
+use anyhow::Error;
+use hex::FromHex;
+
+use proxmox_router::{Permission, Router, RpcEnvironment};
+use proxmox_schema::api;
+
+use pbs_api_types::{
+    PamRealmConfig, PamRealmConfigUpdater, PRIV_REALM_ALLOCATE, PRIV_SYS_AUDIT,
+    PROXMOX_CONFIG_DIGEST_SCHEMA,
+};
+
+use pbs_config::domains;
+
+#[api(
+    returns: {
+        type: PamRealmConfig,
+    },
+    access: {
+        permission: &Permission::Privilege(&["access", "domains"], PRIV_SYS_AUDIT, false),
+    },
+)]
+/// Read the PAM realm configuration
+pub fn read_pam_realm(rpcenv: &mut dyn RpcEnvironment) -> Result<PamRealmConfig, Error> {
+    let (domains, digest) = domains::config()?;
+
+    let config = domains.lookup("pam", "pam")?;
+
+    rpcenv["digest"] = hex::encode(digest).into();
+
+    Ok(config)
+}
+
+#[api]
+#[derive(Serialize, Deserialize)]
+#[serde(rename_all = "kebab-case")]
+/// Deletable property name
+pub enum DeletableProperty {
+    /// Delete the comment property.
+    Comment,
+    /// Delete the default property.
+    Default,
+}
+
+#[api(
+    protected: true,
+    input: {
+        properties: {
+            update: {
+                type: PamRealmConfigUpdater,
+                flatten: true,
+            },
+            delete: {
+                description: "List of properties to delete.",
+                type: Array,
+                optional: true,
+                items: {
+                    type: DeletableProperty,
+                }
+            },
+            digest: {
+                optional: true,
+                schema: PROXMOX_CONFIG_DIGEST_SCHEMA,
+            },
+        },
+    },
+    returns: {
+        type: PamRealmConfig,
+    },
+    access: {
+        permission: &Permission::Privilege(&["access", "domains"], PRIV_REALM_ALLOCATE, false),
+    },
+)]
+/// Update the PAM realm configuration
+pub fn update_pam_realm(
+    update: PamRealmConfigUpdater,
+    delete: Option<Vec<DeletableProperty>>,
+    digest: Option<String>,
+    _rpcenv: &mut dyn RpcEnvironment,
+) -> Result<(), Error> {
+    let _lock = domains::lock_config()?;
+
+    let (mut domains, expected_digest) = domains::config()?;
+
+    if let Some(ref digest) = digest {
+        let digest = <[u8; 32]>::from_hex(digest)?;
+        crate::tools::detect_modified_configuration_file(&digest, &expected_digest)?;
+    }
+
+    let mut config: PamRealmConfig = domains.lookup("pam", "pam")?;
+
+    if let Some(delete) = delete {
+        for delete_prop in delete {
+            match delete_prop {
+                DeletableProperty::Comment => {
+                    config.comment = None;
+                }
+                DeletableProperty::Default => {
+                    config.default = None;
+                }
+            }
+        }
+    }
+
+    if let Some(comment) = update.comment {
+        let comment = comment.trim().to_string();
+        if comment.is_empty() {
+            config.comment = None;
+        } else {
+            config.comment = Some(comment);
+        }
+    }
+
+    if let Some(true) = update.default {
+        pbs_config::domains::unset_default_realm(&mut domains)?;
+        config.default = Some(true);
+    } else {
+        config.default = None;
+    }
+
+    domains.set_data("pam", "pam", &config)?;
+
+    domains::save_config(&domains)?;
+
+    Ok(())
+}
+
+pub const ROUTER: Router = Router::new()
+    .get(&API_METHOD_READ_PAM_REALM)
+    .put(&API_METHOD_UPDATE_PAM_REALM);