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use std::ffi::{CStr, CString};
use std::ptr;
const PAM_CONV: libc::c_int = 5;
const PAM_PROMPT_ECHO_OFF: libc::c_int = 1;
const PAM_PROMPT_ECHO_ON: libc::c_int = 2;
const PAM_ERROR_MSG: libc::c_int = 3;
const PAM_TEXT_INFO: libc::c_int = 4;
#[repr(C)]
struct PamMessage {
msg_style: libc::c_int,
msg: *const libc::c_char,
}
#[repr(C)]
struct PamResponse {
resp: *mut libc::c_char,
resp_retcode: libc::c_int,
}
type PamConvFn = unsafe extern "C" fn(
num_msg: libc::c_int,
msg: *mut *const PamMessage,
resp: *mut *mut PamResponse,
appdata_ptr: *mut libc::c_void,
) -> libc::c_int;
#[repr(C)]
struct PamConv {
conv: PamConvFn,
appdata_ptr: *mut libc::c_void,
}
extern "C" {
fn pam_get_item(
pamh: *const libc::c_void,
item_type: libc::c_int,
item: *mut *const libc::c_void,
) -> libc::c_int;
}
/// Thread-safe wrapper around a raw PAM conversation function pointer.
pub struct RawConv {
conv_fn: PamConvFn,
appdata_ptr: *mut libc::c_void,
}
unsafe impl Send for RawConv {}
impl RawConv {
/// Extract the raw PAM conversation from a PAM handle.
pub fn from_pam_handle(pamh: *mut libc::c_void) -> Option<Self> {
unsafe {
let mut conv_ptr: *const libc::c_void = ptr::null();
let ret = pam_get_item(pamh, PAM_CONV, &mut conv_ptr);
if ret != 0 || conv_ptr.is_null() {
return None;
}
let pam_conv = &*(conv_ptr as *const PamConv);
Some(RawConv {
conv_fn: pam_conv.conv,
appdata_ptr: pam_conv.appdata_ptr,
})
}
}
/// Send a message through the PAM conversation.
/// Returns the response string for prompt types, or None for info/error.
pub fn send(&self, msg_style: libc::c_int, msg: &str) -> Result<Option<CString>, ()> {
let c_msg = CString::new(msg).map_err(|_| ())?;
let pam_msg = PamMessage {
msg_style,
msg: c_msg.as_ptr(),
};
let mut msg_ptr: *const PamMessage = &pam_msg;
let mut resp_ptr: *mut PamResponse = ptr::null_mut();
let ret = unsafe { (self.conv_fn)(1, &mut msg_ptr, &mut resp_ptr, self.appdata_ptr) };
if ret != 0 {
return Err(());
}
if resp_ptr.is_null() {
return Ok(None);
}
let response = unsafe {
let resp = &*resp_ptr;
let result = if resp.resp.is_null() {
None
} else {
let s = CStr::from_ptr(resp.resp).to_owned();
libc::free(resp.resp as *mut libc::c_void);
Some(s)
};
libc::free(resp_ptr as *mut libc::c_void);
result
};
Ok(response)
}
pub fn send_prompt(&self, msg: &str) -> Result<Option<CString>, ()> {
self.send(PAM_PROMPT_ECHO_OFF, msg)
}
pub fn send_info(&self, msg: &str) -> Result<Option<CString>, ()> {
self.send(PAM_TEXT_INFO, msg)
}
pub fn send_error(&self, msg: &str) -> Result<Option<CString>, ()> {
self.send(PAM_ERROR_MSG, msg)
}
}
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