Merge pull request #952 from rumpelsepp/patch-1

use ffi;

use foreign_types::ForeignType;

use foreign_types::ForeignTypeRef;

#[cfg(not(osslconf = "OPENSSL_NO_PSK"))]

#[cfg(any(ossl111, not(osslconf = "OPENSSL_NO_PSK")))]

use libc::c_char;

#[cfg(ossl111)]

use libc::size_t;

use libc::{c_int, c_uchar, c_uint, c_void};

#[cfg(not(osslconf = "OPENSSL_NO_PSK"))]

#[cfg(any(ossl111, not(osslconf = "OPENSSL_NO_PSK")))]

use std::ffi::CStr;

use std::mem;

use std::ptr;