--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libpam-sys/src/funcs/xsso_base.rs	Mon Jun 30 17:47:32 2025 -0400
@@ -0,0 +1,97 @@
+//! Only the very base functions described in the X/SSO specification.
+
+use crate::pam_conv;
+use crate::structs::{pam_handle_t, CleanupCallback};
+use std::ffi::{c_char, c_int, c_void};
+
+extern "C" {
+    /// Account validation.
+    pub fn pam_acct_mgmt(pamh: *mut pam_handle_t, flags: c_int) -> c_int;
+
+    /// Authenticate a user.
+    pub fn pam_authenticate(pamh: *mut pam_handle_t, flags: c_int) -> c_int;
+
+    // Nobody implements pam_authenticate_secondary.
+
+    /// Manage authentication tokens.
+    pub fn pam_chauthtok(pamh: *mut pam_handle_t, flags: c_int) -> c_int;
+
+    /// Close an opened user session.
+    pub fn pam_close_session(pamh: *mut pam_handle_t, flags: c_int) -> c_int;
+
+    /// Ends the PAM transaction.
+    pub fn pam_end(pamh: *mut pam_handle_t, flags: c_int) -> c_int;
+
+    /// Gets module-specific data. PAM still owns the data.
+    pub fn pam_get_data(
+        pamh: *mut pam_handle_t,
+        module_data_name: *const c_char,
+        data: &mut *const c_void,
+    ) -> c_int;
+
+    /// Gets an environment variable.  You own the return value.
+    pub fn pam_getenv(pamh: *mut pam_handle_t, name: *const c_char) -> *mut c_char;
+
+    /// Gets all the environment variables.  You own everything it points to.
+    pub fn pam_getenvlist(pamh: *mut pam_handle_t) -> *mut *mut c_char;
+
+    /// Get information about the transaction.
+    pub fn pam_get_item(
+        pamh: *mut pam_handle_t,
+        item_type: c_int,
+        item: &mut *const c_void,
+    ) -> c_int;
+
+    // Nobody implements pam_get_mapped_authtok.
+    // Nobody implements pam_get_mapped_username.
+
+    /// Get the username.
+    pub fn pam_get_user(
+        pamh: *mut pam_handle_t,
+        user: &mut *const c_char,
+        prompt: *const c_char,
+    ) -> c_int;
+
+    /// Opens a user session.
+    pub fn pam_open_session(pamh: *mut pam_handle_t, flags: c_int) -> c_int;
+
+    /// Sets the value of an environment variable. `namevalue` is copied.
+    pub fn pam_putenv(pamh: *mut pam_handle_t, namevalue: *const c_char) -> c_int;
+
+    /// Update or delete user credentials.
+    pub fn pam_setcred(pamh: *mut pam_handle_t, flags: c_int) -> c_int;
+
+    /// Set module-specific data.
+    pub fn pam_set_data(
+        pamh: *mut pam_handle_t,
+        module_data_name: *const c_char,
+        data: *mut c_void,
+        cleanup: CleanupCallback,
+    ) -> c_int;
+
+    /// Set information about the transaction.  The `item` is copied.
+    pub fn pam_set_item(pamh: *mut pam_handle_t, item_type: c_int, item: *const c_void) -> c_int;
+
+    // Nobody implements pam_set_mapped_authtok.
+    // Nobody implements pam_set_mapped_username.
+
+    // The pam_sm_whatever functions are prototypes for the functions that
+    // a PAM module should implement, not symbols provided by PAM.
+
+    // Nobody implements pam_authenticate_secondary.
+
+    /// Starts a PAM transaction.  The `conv` may or may not be copied.
+    pub fn pam_start(
+        service: *const c_char,
+        user: *const c_char,
+        pam_conv: *mut pam_conv,
+        pamh: &mut *mut pam_handle_t,
+    );
+
+    /// Gets a statically-allocated error string.
+    ///
+    /// All implementations of PAM known to this library (Linux-PAM, OpenPAM,
+    /// and Sun) ignore `pamh` and will accept a null pointer.
+    pub fn pam_strerror(pamh: *const pam_handle_t, error_number: c_int) -> *const c_char;
+
+}