From b15792b8d7c197d84970415fd2525c51aee3996c Mon Sep 17 00:00:00 2001 From: "Joe Richey joerichey@google.com" Date: Wed, 23 Aug 2017 12:29:10 -0700 Subject: Added some documentation and improved security API --- pam/pam.go | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) (limited to 'pam/pam.go') diff --git a/pam/pam.go b/pam/pam.go index 804171d..3049efb 100644 --- a/pam/pam.go +++ b/pam/pam.go @@ -32,12 +32,15 @@ import ( "errors" "fmt" "unsafe" + + "github.com/google/fscrypt/security" ) // Handle wraps the C pam_handle_t type. This is used from within modules. type Handle struct { handle *C.pam_handle_t status C.int + privs *security.Privileges } // NewHandle creates a Handle from a raw pointer. @@ -105,19 +108,28 @@ func (h *Handle) GetItem(i Item) (unsafe.Pointer, error) { return data, h.err() } -// GetIDs retrieves the UID and GID of the corresponding PAM_USER. -func (h *Handle) GetIDs() (uid int, gid int, err error) { +// DropThreadPrivileges sets the effective privileges to that of the PAM user +func (h *Handle) DropThreadPrivileges() error { var pamUsername *C.char + var err error + h.status = C.pam_get_user(h.handle, &pamUsername, nil) if err = h.err(); err != nil { - return 0, 0, err + return err } - pwnam := C.getpwnam(pamUsername) if pwnam == nil { - return 0, 0, fmt.Errorf("unknown user %q", C.GoString(pamUsername)) + return fmt.Errorf("unknown user %q", C.GoString(pamUsername)) } - return int(pwnam.pw_uid), int(pwnam.pw_gid), nil + + h.privs, err = security.DropThreadPrivileges(int(pwnam.pw_uid), int(pwnam.pw_gid)) + return err +} + +// RaiseThreadPrivileges restores the original privileges that were running the +// PAM module (this is usually root). +func (h *Handle) RaiseThreadPrivileges() error { + return security.RaiseThreadPrivileges(h.privs) } func (h *Handle) err() error { -- cgit v1.2.3