Merge pull request #507 from sfackler/ref

Add a unified Ref type

17 files changed, 324 insertions, 681 deletions

diff --git a/openssl/src/asn1.rs b/openssl/src/asn1.rs
index 9a83a5da..a089b41b 100644
--- a/openssl/src/asn1.rs
+++ b/openssl/src/asn1.rs
@@ -1,30 +1,15 @@
 use libc::c_long;
 use std::{ptr, fmt};
-use std::ops::Deref;
-
 use ffi;
-use opaque::Opaque;
 
 use {cvt, cvt_p};
 use bio::MemBio;
 use error::ErrorStack;
+use types::{OpenSslType, Ref};
 
-/// A borrowed Asn1Time
-pub struct Asn1TimeRef(Opaque);
-
-impl Asn1TimeRef {
-    /// Creates a new `Asn1TimeRef` wrapping the provided handle.
-    pub unsafe fn from_ptr<'a>(handle: *mut ffi::ASN1_TIME) -> &'a Asn1TimeRef {
-        &*(handle as *mut _)
-    }
+type_!(Asn1Time, ffi::ASN1_TIME, ffi::ASN1_TIME_free);
 
-    /// Returns the raw handle
-    pub fn as_ptr(&self) -> *mut ffi::ASN1_TIME {
-        self as *const _ as *mut _
-    }
-}
-
-impl fmt::Display for Asn1TimeRef {
+impl fmt::Display for Ref<Asn1Time> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         let mem_bio = try!(MemBio::new());
         let as_str = unsafe {
@@ -35,16 +20,7 @@ impl fmt::Display for Asn1TimeRef {
     }
 }
 
-
-/// Corresponds to the ASN.1 structure Time defined in RFC5280
-pub struct Asn1Time(*mut ffi::ASN1_TIME);
-
 impl Asn1Time {
-    /// Wraps existing ASN1_TIME and takes ownership
-    pub unsafe fn from_ptr(handle: *mut ffi::ASN1_TIME) -> Asn1Time {
-        Asn1Time(handle)
-    }
-
     fn from_period(period: c_long) -> Result<Asn1Time, ErrorStack> {
         ffi::init();
 
@@ -59,17 +35,3 @@ impl Asn1Time {
         Asn1Time::from_period(days as c_long * 60 * 60 * 24)
     }
 }
-
-impl Deref for Asn1Time {
-    type Target = Asn1TimeRef;
-
-    fn deref(&self) -> &Asn1TimeRef {
-        unsafe { Asn1TimeRef::from_ptr(self.0) }
-    }
-}
-
-impl Drop for Asn1Time {
-    fn drop(&mut self) {
-        unsafe { ffi::ASN1_TIME_free(self.as_ptr()) };
-    }
-}
diff --git a/openssl/src/bn.rs b/openssl/src/bn.rs
index 78684d0a..7542b25a 100644
--- a/openssl/src/bn.rs
+++ b/openssl/src/bn.rs
@@ -3,12 +3,12 @@ use libc::c_int;
 use std::cmp::Ordering;
 use std::ffi::CString;
 use std::{fmt, ptr};
-use std::ops::{Add, Div, Mul, Neg, Rem, Shl, Shr, Sub, Deref, DerefMut};
+use std::ops::{Add, Div, Mul, Neg, Rem, Shl, Shr, Sub, Deref};
 
 use {cvt, cvt_p, cvt_n};
 use crypto::CryptoString;
 use error::ErrorStack;
-use opaque::Opaque;
+use types::{Ref, OpenSslType};
 
 /// Specifies the desired properties of a randomly generated `BigNum`.
 #[derive(Copy, Clone)]
@@ -23,16 +23,7 @@ pub enum RNGProperty {
     TwoMsbOne = 1,
 }
 
-/// A context object for `BigNum` operations.
-pub struct BnCtx(*mut ffi::BN_CTX);
-
-impl Drop for BnCtx {
-    fn drop(&mut self) {
-        unsafe {
-            ffi::BN_CTX_free(self.0);
-        }
-    }
-}
+type_!(BnCtx, ffi::BN_CTX, ffi::BN_CTX_free);
 
 impl BnCtx {
     /// Returns a new `BnCtx`.
@@ -40,25 +31,21 @@ impl BnCtx {
         unsafe { cvt_p(ffi::BN_CTX_new()).map(BnCtx) }
     }
 
-    pub fn as_ptr(&self) -> *mut ffi::BN_CTX {
-        self.0
-    }
-
     /// Places the result of `a * b` in `r`.
     pub fn mul(&mut self,
-               r: &mut BigNumRef,
-               a: &BigNumRef,
-               b: &BigNumRef)
+               r: &mut Ref<BigNum>,
+               a: &Ref<BigNum>,
+               b: &Ref<BigNum>)
                -> Result<(), ErrorStack> {
         unsafe { cvt(ffi::BN_mul(r.as_ptr(), a.as_ptr(), b.as_ptr(), self.as_ptr())).map(|_| ()) }
     }
 
     /// Places the result of `a / b` in `dv` and `a mod b` in `rem`.
     pub fn div(&mut self,
-               dv: Option<&mut BigNumRef>,
-               rem: Option<&mut BigNumRef>,
-               a: &BigNumRef,
-               b: &BigNumRef)
+               dv: Option<&mut Ref<BigNum>>,
+               rem: Option<&mut Ref<BigNum>>,
+               a: &Ref<BigNum>,
+               b: &Ref<BigNum>)
                -> Result<(), ErrorStack> {
         unsafe {
             cvt(ffi::BN_div(dv.map(|b| b.as_ptr()).unwrap_or(ptr::null_mut()),
@@ -71,25 +58,25 @@ impl BnCtx {
     }
 
     /// Places the result of `a²` in `r`.
-    pub fn sqr(&mut self, r: &mut BigNumRef, a: &BigNumRef) -> Result<(), ErrorStack> {
+    pub fn sqr(&mut self, r: &mut Ref<BigNum>, a: &Ref<BigNum>) -> Result<(), ErrorStack> {
         unsafe { cvt(ffi::BN_sqr(r.as_ptr(), a.as_ptr(), self.as_ptr())).map(|_| ()) }
     }
 
     /// Places the result of `a mod m` in `r`.
     pub fn nnmod(&mut self,
-                 r: &mut BigNumRef,
-                 a: &BigNumRef,
-                 m: &BigNumRef)
+                 r: &mut Ref<BigNum>,
+                 a: &Ref<BigNum>,
+                 m: &Ref<BigNum>)
                  -> Result<(), ErrorStack> {
         unsafe { cvt(ffi::BN_nnmod(r.as_ptr(), a.as_ptr(), m.as_ptr(), self.0)).map(|_| ()) }
     }
 
     /// Places the result of `(a + b) mod m` in `r`.
     pub fn mod_add(&mut self,
-                   r: &mut BigNumRef,
-                   a: &BigNumRef,
-                   b: &BigNumRef,
-                   m: &BigNumRef)
+                   r: &mut Ref<BigNum>,
+                   a: &Ref<BigNum>,
+                   b: &Ref<BigNum>,
+                   m: &Ref<BigNum>)
                    -> Result<(), ErrorStack> {
         unsafe {
             cvt(ffi::BN_mod_add(r.as_ptr(), a.as_ptr(), b.as_ptr(), m.as_ptr(), self.0)).map(|_| ())
@@ -98,10 +85,10 @@ impl BnCtx {
 
     /// Places the result of `(a - b) mod m` in `r`.
     pub fn mod_sub(&mut self,
-                   r: &mut BigNumRef,
-                   a: &BigNumRef,
-                   b: &BigNumRef,
-                   m: &BigNumRef)
+                   r: &mut Ref<BigNum>,
+                   a: &Ref<BigNum>,
+                   b: &Ref<BigNum>,
+                   m: &Ref<BigNum>)
                    -> Result<(), ErrorStack> {
         unsafe {
             cvt(ffi::BN_mod_sub(r.as_ptr(), a.as_ptr(), b.as_ptr(), m.as_ptr(), self.0)).map(|_| ())
@@ -110,10 +97,10 @@ impl BnCtx {
 
     /// Places the result of `(a * b) mod m` in `r`.
     pub fn mod_mul(&mut self,
-                   r: &mut BigNumRef,
-                   a: &BigNumRef,
-                   b: &BigNumRef,
-                   m: &BigNumRef)
+                   r: &mut Ref<BigNum>,
+                   a: &Ref<BigNum>,
+                   b: &Ref<BigNum>,
+                   m: &Ref<BigNum>)
                    -> Result<(), ErrorStack> {
         unsafe {
             cvt(ffi::BN_mod_mul(r.as_ptr(), a.as_ptr(), b.as_ptr(), m.as_ptr(), self.0)).map(|_| ())
@@ -122,28 +109,28 @@ impl BnCtx {
 
     /// Places the result of `a² mod m` in `r`.
     pub fn mod_sqr(&mut self,
-                   r: &mut BigNumRef,
-                   a: &BigNumRef,
-                   m: &BigNumRef)
+                   r: &mut Ref<BigNum>,
+                   a: &Ref<BigNum>,
+                   m: &Ref<BigNum>)
                    -> Result<(), ErrorStack> {
         unsafe { cvt(ffi::BN_mod_sqr(r.as_ptr(), a.as_ptr(), m.as_ptr(), self.0)).map(|_| ()) }
     }
 
     /// Places the result of `a^p` in `r`.
     pub fn exp(&mut self,
-               r: &mut BigNumRef,
-               a: &BigNumRef,
-               p: &BigNumRef)
+               r: &mut Ref<BigNum>,
+               a: &Ref<BigNum>,
+               p: &Ref<BigNum>)
                -> Result<(), ErrorStack> {
         unsafe { cvt(ffi::BN_exp(r.as_ptr(), a.as_ptr(), p.as_ptr(), self.0)).map(|_| ()) }
     }
 
     /// Places the result of `a^p mod m` in `r`.
     pub fn mod_exp(&mut self,
-                   r: &mut BigNumRef,
-                   a: &BigNumRef,
-                   p: &BigNumRef,
-                   m: &BigNumRef)
+                   r: &mut Ref<BigNum>,
+                   a: &Ref<BigNum>,
+                   p: &Ref<BigNum>,
+                   m: &Ref<BigNum>)
                    -> Result<(), ErrorStack> {
         unsafe {
             cvt(ffi::BN_mod_exp(r.as_ptr(), a.as_ptr(), p.as_ptr(), m.as_ptr(), self.0)).map(|_| ())
@@ -152,9 +139,9 @@ impl BnCtx {
 
     /// Places the inverse of `a` modulo `n` in `r`.
     pub fn mod_inverse(&mut self,
-                       r: &mut BigNumRef,
-                       a: &BigNumRef,
-                       n: &BigNumRef)
+                       r: &mut Ref<BigNum>,
+                       a: &Ref<BigNum>,
+                       n: &Ref<BigNum>)
                        -> Result<(), ErrorStack> {
         unsafe {
             cvt_p(ffi::BN_mod_inverse(r.as_ptr(), a.as_ptr(), n.as_ptr(), self.as_ptr()))
@@ -164,9 +151,9 @@ impl BnCtx {
 
     /// Places the greatest common denominator of `a` and `b` in `r`.
     pub fn gcd(&mut self,
-               r: &mut BigNumRef,
-               a: &BigNumRef,
-               b: &BigNumRef)
+               r: &mut Ref<BigNum>,
+               a: &Ref<BigNum>,
+               b: &Ref<BigNum>)
                -> Result<(), ErrorStack> {
         unsafe { cvt(ffi::BN_gcd(r.as_ptr(), a.as_ptr(), b.as_ptr(), self.as_ptr())).map(|_| ()) }
     }
@@ -176,7 +163,7 @@ impl BnCtx {
     /// Performs a Miller-Rabin probabilistic primality test with `checks` iterations.
     ///
     /// Returns `true` if `p` is prime with an error probability of less than `0.25 ^ checks`.
-    pub fn is_prime(&mut self, p: &BigNumRef, checks: i32) -> Result<bool, ErrorStack> {
+    pub fn is_prime(&mut self, p: &Ref<BigNum>, checks: i32) -> Result<bool, ErrorStack> {
         unsafe {
             cvt_n(ffi::BN_is_prime_ex(p.as_ptr(), checks.into(), self.as_ptr(), ptr::null_mut()))
                 .map(|r| r != 0)
@@ -193,7 +180,7 @@ impl BnCtx {
     ///
     /// Returns `true` if `p` is prime with an error probability of less than `0.25 ^ checks`.
     pub fn is_prime_fasttest(&mut self,
-                             p: &BigNumRef,
+                             p: &Ref<BigNum>,
                              checks: i32,
                              do_trial_division: bool)
                              -> Result<bool, ErrorStack> {
@@ -214,7 +201,7 @@ impl BnCtx {
     /// * `bits`: Length of the number in bits.
     /// * `prop`: The desired properties of the number.
     /// * `odd`: If `true`, the generated number will be odd.
-    pub fn rand(r: &mut BigNumRef,
+    pub fn rand(r: &mut Ref<BigNum>,
                 bits: i32,
                 prop: RNGProperty,
                 odd: bool)
@@ -225,7 +212,7 @@ impl BnCtx {
     }
 
     /// The cryptographically weak counterpart to `checked_new_random`.
-    pub fn pseudo_rand(r: &mut BigNumRef,
+    pub fn pseudo_rand(r: &mut Ref<BigNum>,
                        bits: i32,
                        prop: RNGProperty,
                        odd: bool)
@@ -237,22 +224,7 @@ impl BnCtx {
     }
 }
 
-/// A borrowed, signed, arbitrary-precision integer.
-pub struct BigNumRef(Opaque);
-
-impl BigNumRef {
-    pub unsafe fn from_ptr<'a>(handle: *mut ffi::BIGNUM) -> &'a BigNumRef {
-        &*(handle as *mut _)
-    }
-
-    pub unsafe fn from_ptr_mut<'a>(handle: *mut ffi::BIGNUM) -> &'a mut BigNumRef {
-        &mut *(handle as *mut _)
-    }
-
-    pub fn as_ptr(&self) -> *mut ffi::BIGNUM {
-        self as *const _ as *mut _
-    }
-
+impl Ref<BigNum> {
     /// Adds a `u32` to `self`.
     pub fn add_word(&mut self, w: u32) -> Result<(), ErrorStack> {
         unsafe { cvt(ffi::BN_add_word(self.as_ptr(), w as ffi::BN_ULONG)).map(|_| ()) }
@@ -294,12 +266,12 @@ impl BigNumRef {
 
     /// Places a cryptographically-secure pseudo-random number nonnegative
     /// number less than `self` in `rnd`.
-    pub fn rand_in_range(&self, rnd: &mut BigNumRef) -> Result<(), ErrorStack> {
+    pub fn rand_in_range(&self, rnd: &mut Ref<BigNum>) -> Result<(), ErrorStack> {
         unsafe { cvt(ffi::BN_rand_range(self.as_ptr(), rnd.as_ptr())).map(|_| ()) }
     }
 
     /// The cryptographically weak counterpart to `rand_in_range`.
-    pub fn pseudo_rand_in_range(&self, rnd: &mut BigNumRef) -> Result<(), ErrorStack> {
+    pub fn pseudo_rand_in_range(&self, rnd: &mut Ref<BigNum>) -> Result<(), ErrorStack> {
         unsafe { cvt(ffi::BN_pseudo_rand_range(self.as_ptr(), rnd.as_ptr())).map(|_| ()) }
     }
 
@@ -330,32 +302,32 @@ impl BigNumRef {
     }
 
     /// Places `self << 1` in `r`.
-    pub fn lshift1(&self, r: &mut BigNumRef) -> Result<(), ErrorStack> {
+    pub fn lshift1(&self, r: &mut Ref<BigNum>) -> Result<(), ErrorStack> {
         unsafe { cvt(ffi::BN_lshift1(r.as_ptr(), self.as_ptr())).map(|_| ()) }
     }
 
     /// Places `self >> 1` in `r`.
-    pub fn rshift1(&self, r: &mut BigNumRef) -> Result<(), ErrorStack> {
+    pub fn rshift1(&self, r: &mut Ref<BigNum>) -> Result<(), ErrorStack> {
         unsafe { cvt(ffi::BN_rshift1(r.as_ptr(), self.as_ptr())).map(|_| ()) }
     }
 
     /// Places `self + b` in `r`.
-    pub fn add(&self, r: &mut BigNumRef, b: &BigNumRef) -> Result<(), ErrorStack> {
+    pub fn add(&self, r: &mut Ref<BigNum>, b: &Ref<BigNum>) -> Result<(), ErrorStack> {
         unsafe { cvt(ffi::BN_add(r.as_ptr(), self.as_ptr(), b.as_ptr())).map(|_| ()) }
     }
 
     /// Places `self - b` in `r`.
-    pub fn sub(&self, r: &mut BigNumRef, b: &BigNumRef) -> Result<(), ErrorStack> {
+    pub fn sub(&self, r: &mut Ref<BigNum>, b: &Ref<BigNum>) -> Result<(), ErrorStack> {
         unsafe { cvt(ffi::BN_sub(r.as_ptr(), self.as_ptr(), b.as_ptr())).map(|_| ()) }
     }
 
     /// Places `self << n` in `r`.
-    pub fn lshift(&self, r: &mut BigNumRef, b: i32) -> Result<(), ErrorStack> {
+    pub fn lshift(&self, r: &mut Ref<BigNum>, b: i32) -> Result<(), ErrorStack> {
         unsafe { cvt(ffi::BN_lshift(r.as_ptr(), self.as_ptr(), b.into())).map(|_| ()) }
     }
 
     /// Places `self >> n` in `r`.
-    pub fn rshift(&self, r: &mut BigNumRef, n: i32) -> Result<(), ErrorStack> {
+    pub fn rshift(&self, r: &mut Ref<BigNum>, n: i32) -> Result<(), ErrorStack> {
         unsafe { cvt(ffi::BN_rshift(r.as_ptr(), self.as_ptr(), n.into())).map(|_| ()) }
     }
 
@@ -378,7 +350,7 @@ impl BigNumRef {
     ///
     /// assert_eq!(s.ucmp(&o), Ordering::Equal);
     /// ```
-    pub fn ucmp(&self, oth: &BigNumRef) -> Ordering {
+    pub fn ucmp(&self, oth: &Ref<BigNum>) -> Ordering {
         unsafe { ffi::BN_ucmp(self.as_ptr(), oth.as_ptr()).cmp(&0) }
     }
 
@@ -459,13 +431,7 @@ impl BigNumRef {
     }
 }
 
-/// An owned, signed, arbitrary-precision integer.
-///
-/// `BigNum` provides wrappers around OpenSSL's checked arithmetic functions.
-/// Additionally, it implements the standard operators (`std::ops`), which
-/// perform unchecked arithmetic, unwrapping the returned `Result` of the
-/// checked operations.
-pub struct BigNum(*mut ffi::BIGNUM);
+type_!(BigNum, ffi::BIGNUM, ffi::BN_clear_free);
 
 impl BigNum {
     /// Creates a new `BigNum` with the value 0.
@@ -504,10 +470,6 @@ impl BigNum {
         }
     }
 
-    pub unsafe fn from_ptr(handle: *mut ffi::BIGNUM) -> BigNum {
-        BigNum(handle)
-    }
-
     /// Creates a new `BigNum` from an unsigned, big-endian encoded number of arbitrary length.
     ///
     /// ```
@@ -532,11 +494,11 @@ impl BigNum {
     /// * `safe`: If true, returns a "safe" prime `p` so that `(p-1)/2` is also prime.
     /// * `add`/`rem`: If `add` is set to `Some(add)`, `p % add == rem` will hold, where `p` is the
     ///   generated prime and `rem` is `1` if not specified (`None`).
-    pub fn generate_prime(r: &mut BigNumRef,
+    pub fn generate_prime(r: &mut Ref<BigNum>,
                           bits: i32,
                           safe: bool,
-                          add: Option<&BigNumRef>,
-                          rem: Option<&BigNumRef>)
+                          add: Option<&Ref<BigNum>>,
+                          rem: Option<&Ref<BigNum>>)
                           -> Result<(), ErrorStack> {
         unsafe {
             cvt(ffi::BN_generate_prime_ex(r.as_ptr(),
@@ -550,35 +512,13 @@ impl BigNum {
     }
 }
 
-impl Drop for BigNum {
-    fn drop(&mut self) {
-        unsafe {
-            ffi::BN_clear_free(self.as_ptr());
-        }
-    }
-}
-
-impl Deref for BigNum {
-    type Target = BigNumRef;
-
-    fn deref(&self) -> &BigNumRef {
-        unsafe { BigNumRef::from_ptr(self.0) }
-    }
-}
-
-impl DerefMut for BigNum {
-    fn deref_mut(&mut self) -> &mut BigNumRef {
-        unsafe { BigNumRef::from_ptr_mut(self.0) }
-    }
-}
-
-impl AsRef<BigNumRef> for BigNum {
-    fn as_ref(&self) -> &BigNumRef {
+impl AsRef<Ref<BigNum>> for BigNum {
+    fn as_ref(&self) -> &Ref<BigNum> {
         self.deref()
     }
 }
 
-impl fmt::Debug for BigNumRef {
+impl fmt::Debug for Ref<BigNum> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match self.to_dec_str() {
             Ok(s) => f.write_str(&s),
@@ -596,7 +536,7 @@ impl fmt::Debug for BigNum {
     }
 }
 
-impl fmt::Display for BigNumRef {
+impl fmt::Display for Ref<BigNum> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match self.to_dec_str() {
             Ok(s) => f.write_str(&s),
@@ -614,19 +554,19 @@ impl fmt::Display for BigNum {
     }
 }
 
-impl PartialEq<BigNumRef> for BigNumRef {
-    fn eq(&self, oth: &BigNumRef) -> bool {
+impl PartialEq<Ref<BigNum>> for Ref<BigNum> {
+    fn eq(&self, oth: &Ref<BigNum>) -> bool {
         self.cmp(oth) == Ordering::Equal
     }
 }
 
-impl PartialEq<BigNum> for BigNumRef {
+impl PartialEq<BigNum> for Ref<BigNum> {
     fn eq(&self, oth: &BigNum) -> bool {
         self.eq(oth.deref())
     }
 }
 
-impl Eq for BigNumRef {}
+impl Eq for Ref<BigNum> {}
 
 impl PartialEq for BigNum {
     fn eq(&self, oth: &BigNum) -> bool {
@@ -634,28 +574,28 @@ impl PartialEq for BigNum {
     }
 }
 
-impl PartialEq<BigNumRef> for BigNum {
-    fn eq(&self, oth: &BigNumRef) -> bool {
+impl PartialEq<Ref<BigNum>> for BigNum {
+    fn eq(&self, oth: &Ref<BigNum>) -> bool {
         self.deref().eq(oth)
     }
 }
 
 impl Eq for BigNum {}
 
-impl PartialOrd<BigNumRef> for BigNumRef {
-    fn partial_cmp(&self, oth: &BigNumRef) -> Option<Ordering> {
+impl PartialOrd<Ref<BigNum>> for Ref<BigNum> {
+    fn partial_cmp(&self, oth: &Ref<BigNum>) -> Option<Ordering> {
         Some(self.cmp(oth))
     }
 }
 
-impl PartialOrd<BigNum> for BigNumRef {
+impl PartialOrd<BigNum> for Ref<BigNum> {
     fn partial_cmp(&self, oth: &BigNum) -> Option<Ordering> {
         Some(self.cmp(oth.deref()))
     }
 }
 
-impl Ord for BigNumRef {
-    fn cmp(&self, oth: &BigNumRef) -> Ordering {
+impl Ord for Ref<BigNum> {
+    fn cmp(&self, oth: &Ref<BigNum>) -> Ordering {
         unsafe { ffi::BN_cmp(self.as_ptr(), oth.as_ptr()).cmp(&0) }
     }
 }
@@ -666,8 +606,8 @@ impl PartialOrd for BigNum {
     }
 }
 
-impl PartialOrd<BigNumRef> for BigNum {
-    fn partial_cmp(&self, oth: &BigNumRef) -> Option<Ordering> {
+impl PartialOrd<Ref<BigNum>> for BigNum {
+    fn partial_cmp(&self, oth: &Ref<BigNum>) -> Option<Ordering> {
         self.deref().partial_cmp(oth)
     }
 }
@@ -680,7 +620,7 @@ impl Ord for BigNum {
 
 macro_rules! delegate {
     ($t:ident, $m:ident) => {
-        impl<'a, 'b> $t<&'b BigNum> for &'a BigNumRef {
+        impl<'a, 'b> $t<&'b BigNum> for &'a Ref<BigNum> {
             type Output = BigNum;
 
             fn $m(self, oth: &BigNum) -> BigNum {
@@ -688,10 +628,10 @@ macro_rules! delegate {
             }
         }
 
-        impl<'a, 'b> $t<&'b BigNumRef> for &'a BigNum {
+        impl<'a, 'b> $t<&'b Ref<BigNum>> for &'a BigNum {
             type Output = BigNum;
 
-            fn $m(self, oth: &BigNumRef) -> BigNum {
+            fn $m(self, oth: &Ref<BigNum>) -> BigNum {
                 $t::$m(self.deref(), oth)
             }
         }
@@ -706,10 +646,10 @@ macro_rules! delegate {
     }
 }
 
-impl<'a, 'b> Add<&'b BigNumRef> for &'a BigNumRef {
+impl<'a, 'b> Add<&'b Ref<BigNum>> for &'a Ref<BigNum> {
     type Output = BigNum;
 
-    fn add(self, oth: &BigNumRef) -> BigNum {
+    fn add(self, oth: &Ref<BigNum>) -> BigNum {
         let mut r = BigNum::new().unwrap();
         self.add(&mut r, oth).unwrap();
         r
@@ -718,10 +658,10 @@ impl<'a, 'b> Add<&'b BigNumRef> for &'a BigNumRef {
 
 delegate!(Add, add);
 
-impl<'a, 'b> Sub<&'b BigNumRef> for &'a BigNumRef {
+impl<'a, 'b> Sub<&'b Ref<BigNum>> for &'a Ref<BigNum> {
     type Output = BigNum;
 
-    fn sub(self, oth: &BigNumRef) -> BigNum {
+    fn sub(self, oth: &Ref<BigNum>) -> BigNum {
         let mut r = BigNum::new().unwrap();
         self.sub(&mut r, oth).unwrap();
         r
@@ -730,10 +670,10 @@ impl<'a, 'b> Sub<&'b BigNumRef> for &'a BigNumRef {
 
 delegate!(Sub, sub);
 
-impl<'a, 'b> Mul<&'b BigNumRef> for &'a BigNumRef {
+impl<'a, 'b> Mul<&'b Ref<BigNum>> for &'a Ref<BigNum> {
     type Output = BigNum;
 
-    fn mul(self, oth: &BigNumRef) -> BigNum {
+    fn mul(self, oth: &Ref<BigNum>) -> BigNum {
         let mut ctx = BnCtx::new().unwrap();
         let mut r = BigNum::new().unwrap();
         ctx.mul(&mut r, self, oth).unwrap();
@@ -743,10 +683,10 @@ impl<'a, 'b> Mul<&'b BigNumRef> for &'a BigNumRef {
 
 delegate!(Mul, mul);
 
-impl<'a, 'b> Div<&'b BigNumRef> for &'a BigNumRef {
+impl<'a, 'b> Div<&'b Ref<BigNum>> for &'a Ref<BigNum> {
     type Output = BigNum;
 
-    fn div(self, oth: &'b BigNumRef) -> BigNum {
+    fn div(self, oth: &'b Ref<BigNum>) -> BigNum {
         let mut ctx = BnCtx::new().unwrap();
         let mut dv = BigNum::new().unwrap();
         ctx.div(Some(&mut dv), None, self, oth).unwrap();
@@ -756,10 +696,10 @@ impl<'a, 'b> Div<&'b BigNumRef> for &'a BigNumRef {
 
 delegate!(Div, div);
 
-impl<'a, 'b> Rem<&'b BigNumRef> for &'a BigNumRef {
+impl<'a, 'b> Rem<&'b Ref<BigNum>> for &'a Ref<BigNum> {
     type Output = BigNum;
 
-    fn rem(self, oth: &'b BigNumRef) -> BigNum {
+    fn rem(self, oth: &'b Ref<BigNum>) -> BigNum {
         let mut ctx = BnCtx::new().unwrap();
         let mut rem = BigNum::new().unwrap();
         ctx.div(None, Some(&mut rem), self, oth).unwrap();
@@ -769,7 +709,7 @@ impl<'a, 'b> Rem<&'b BigNumRef> for &'a BigNumRef {
 
 delegate!(Rem, rem);
 
-impl<'a> Shl<i32> for &'a BigNumRef {
+impl<'a> Shl<i32> for &'a Ref<BigNum> {
     type Output = BigNum;
 
     fn shl(self, n: i32) -> BigNum {
@@ -787,7 +727,7 @@ impl<'a> Shl<i32> for &'a BigNum {
     }
 }
 
-impl<'a> Shr<i32> for &'a BigNumRef {
+impl<'a> Shr<i32> for &'a Ref<BigNum> {
     type Output = BigNum;
 
     fn shr(self, n: i32) -> BigNum {
@@ -805,7 +745,7 @@ impl<'a> Shr<i32> for &'a BigNum {
     }
 }
 
-impl<'a> Neg for &'a BigNumRef {
+impl<'a> Neg for &'a Ref<BigNum> {
     type Output = BigNum;
 
     fn neg(self) -> BigNum {
diff --git a/openssl/src/dh.rs b/openssl/src/dh.rs
index 5c5ea05e..4ae145d6 100644
--- a/openssl/src/dh.rs
+++ b/openssl/src/dh.rs
@@ -3,25 +3,12 @@ use error::ErrorStack;
 use bio::MemBioSlice;
 use std::ptr;
 use std::mem;
-use std::ops::Deref;
 
 use {cvt, cvt_p};
 use bn::BigNum;
-use opaque::Opaque;
+use types::OpenSslType;
 
-pub struct DhRef(Opaque);
-
-impl DhRef {
-    pub unsafe fn from_ptr<'a>(ptr: *mut ffi::DH) -> &'a DhRef {
-        &*(ptr as *mut _)
-    }
-
-    pub fn as_ptr(&self) -> *mut ffi::DH {
-        self as *const _ as *mut _
-    }
-}
-
-pub struct Dh(*mut ffi::DH);
+type_!(Dh, ffi::DH, ffi::DH_free);
 
 impl Dh {
     pub fn from_params(p: BigNum, g: BigNum, q: BigNum) -> Result<Dh, ErrorStack> {
@@ -63,20 +50,6 @@ impl Dh {
     }
 }
 
-impl Drop for Dh {
-    fn drop(&mut self) {
-        unsafe { ffi::DH_free(self.0) }
-    }
-}
-
-impl Deref for Dh {
-    type Target = DhRef;
-
-    fn deref(&self) -> &DhRef {
-        unsafe { DhRef::from_ptr(self.0) }
-    }
-}
-
 #[cfg(ossl110)]
 mod compat {
     pub use ffi::DH_set0_pqg;
diff --git a/openssl/src/dsa.rs b/openssl/src/dsa.rs
index e92b8ca3..6efa7050 100644
--- a/openssl/src/dsa.rs
+++ b/openssl/src/dsa.rs
@@ -2,26 +2,17 @@ use error::ErrorStack;
 use ffi;
 use libc::{c_int, c_char, c_void};
 use std::fmt;
-use std::ops::Deref;
 use std::ptr;
 
-use {cvt, cvt_p};
-use bn::BigNumRef;
 use bio::{MemBio, MemBioSlice};
+use bn::BigNum;
+use {cvt, cvt_p};
+use types::Ref;
 use util::{CallbackState, invoke_passwd_cb};
-use opaque::Opaque;
-
-pub struct DsaRef(Opaque);
 
-impl DsaRef {
-    pub unsafe fn from_ptr<'a>(ptr: *mut ffi::DSA) -> &'a DsaRef {
-        &*(ptr as *mut _)
-    }
-
-    pub fn as_ptr(&self) -> *mut ffi::DSA {
-        self as *const _ as *mut _
-    }
+type_!(Dsa, ffi::DSA, ffi::DSA_free);
 
+impl Ref<Dsa> {
     /// Writes an DSA private key as unencrypted PEM formatted data
     pub fn private_key_to_pem(&self) -> Result<Vec<u8>, ErrorStack> {
         assert!(self.has_private_key());
@@ -53,35 +44,35 @@ impl DsaRef {
         }
     }
 
-    pub fn p(&self) -> Option<&BigNumRef> {
+    pub fn p(&self) -> Option<&Ref<BigNum>> {
         unsafe {
             let p = compat::pqg(self.as_ptr())[0];
             if p.is_null() {
                 None
             } else {
-                Some(BigNumRef::from_ptr(p as *mut _))
+                Some(Ref::<BigNum>::from_ptr(p as *mut _))
             }
         }
     }
 
-    pub fn q(&self) -> Option<&BigNumRef> {
+    pub fn q(&self) -> Option<&Ref<BigNum>> {
         unsafe {
             let q = compat::pqg(self.as_ptr())[1];
             if q.is_null() {
                 None
             } else {
-                Some(BigNumRef::from_ptr(q as *mut _))
+                Some(Ref::<BigNum>::from_ptr(q as *mut _))
             }
         }
     }
 
-    pub fn g(&self) -> Option<&BigNumRef> {
+    pub fn g(&self) -> Option<&Ref<BigNum>> {
         unsafe {
             let g = compat::pqg(self.as_ptr())[2];
             if g.is_null() {
                 None
             } else {
-                Some(BigNumRef::from_ptr(g as *mut _))
+                Some(Ref::<BigNum>::from_ptr(g as *mut _))
             }
         }
     }
@@ -95,21 +86,7 @@ impl DsaRef {
     }
 }
 
-pub struct Dsa(*mut ffi::DSA);
-
-impl Drop for Dsa {
-    fn drop(&mut self) {
-        unsafe {
-            ffi::DSA_free(self.0);
-        }
-    }
-}
-
 impl Dsa {
-    pub unsafe fn from_ptr(dsa: *mut ffi::DSA) -> Dsa {
-        Dsa(dsa)
-    }
-
     /// Generate a DSA key pair.
     pub fn generate(bits: u32) -> Result<Dsa, ErrorStack> {
         unsafe {
@@ -121,7 +98,7 @@ impl Dsa {
                                                      ptr::null_mut(),
                                                      ptr::null_mut(),
                                                      ptr::null_mut())));
-            try!(cvt(ffi::DSA_generate_key(dsa .0)));
+            try!(cvt(ffi::DSA_generate_key(dsa.0)));
             Ok(dsa)
         }
     }
@@ -177,11 +154,9 @@ impl Dsa {
     }
 }
 
-impl Deref for Dsa {
-    type Target = DsaRef;
-
-    fn deref(&self) -> &DsaRef {
-        unsafe { DsaRef::from_ptr(self.0) }
+impl fmt::Debug for Dsa {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "DSA")
     }
 }
 
@@ -216,12 +191,6 @@ mod compat {
     }
 }
 
-impl fmt::Debug for Dsa {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "DSA")
-    }
-}
-
 #[cfg(test)]
 mod test {
     use libc::c_char;
diff --git a/openssl/src/ec_key.rs b/openssl/src/ec_key.rs
index 81b790aa..95175eaa 100644
--- a/openssl/src/ec_key.rs
+++ b/openssl/src/ec_key.rs
@@ -1,49 +1,15 @@
 use ffi;
-use std::ops::Deref;
 
 use cvt_p;
 use error::ErrorStack;
 use nid::Nid;
-use opaque::Opaque;
 
-pub struct EcKeyRef(Opaque);
-
-impl EcKeyRef {
-    pub unsafe fn from_ptr<'a>(ptr: *mut ffi::EC_KEY) -> &'a EcKeyRef {
-        &*(ptr as *mut _)
-    }
-
-    pub fn as_ptr(&self) -> *mut ffi::EC_KEY {
-        self as *const _ as *mut _
-    }
-}
-
-pub struct EcKey(*mut ffi::EC_KEY);
-
-impl Drop for EcKey {
-    fn drop(&mut self) {
-        unsafe {
-            ffi::EC_KEY_free(self.0);
-        }
-    }
-}
+type_!(EcKey, ffi::EC_KEY, ffi::EC_KEY_free);
 
 impl EcKey {
     pub fn new_by_curve_name(nid: Nid) -> Result<EcKey, ErrorStack> {
         unsafe { cvt_p(ffi::EC_KEY_new_by_curve_name(nid.as_raw())).map(EcKey) }
     }
-
-    pub unsafe fn from_ptr(ptr: *mut ffi::EC_KEY) -> EcKey {
-        EcKey(ptr)
-    }
-}
-
-impl Deref for EcKey {
-    type Target = EcKeyRef;
-
-    fn deref(&self) -> &EcKeyRef {
-        unsafe { EcKeyRef::from_ptr(self.0) }
-    }
 }
 
 #[cfg(test)]
diff --git a/openssl/src/lib.rs b/openssl/src/lib.rs
index f335c097..d053606f 100644
--- a/openssl/src/lib.rs
+++ b/openssl/src/lib.rs
@@ -20,8 +20,45 @@ use libc::c_int;
 
 use error::ErrorStack;
 
+macro_rules! type_ {
+    ($n:ident, $c:path, $d:path) => {
+        pub struct $n(*mut $c);
+
+        unsafe impl ::types::OpenSslType for $n {
+            type CType = $c;
+
+            unsafe fn from_ptr(ptr: *mut $c) -> $n {
+                $n(ptr)
+            }
+
+            fn as_ptr(&self) -> *mut $c {
+                self.0
+            }
+        }
+
+        impl Drop for $n {
+            fn drop(&mut self) {
+                unsafe { $d(self.0) }
+            }
+        }
+
+        impl ::std::ops::Deref for $n {
+            type Target = ::types::Ref<$n>;
+
+            fn deref(&self) -> &::types::Ref<$n> {
+                unsafe { ::types::Ref::from_ptr(self.0) }
+            }
+        }
+
+        impl ::std::ops::DerefMut for $n {
+            fn deref_mut(&mut self) -> &mut ::types::Ref<$n> {
+                unsafe { ::types::Ref::from_ptr_mut(self.0) }
+            }
+        }
+    }
+}
+
 mod bio;
-mod opaque;
 mod util;
 pub mod asn1;
 pub mod bn;
@@ -37,6 +74,7 @@ pub mod pkcs12;
 pub mod pkcs5;
 pub mod pkey;
 pub mod rand;
+pub mod types;
 pub mod rsa;
 pub mod sign;
 pub mod ssl;
diff --git a/openssl/src/opaque.rs b/openssl/src/opaque.rs
deleted file mode 100644
index 9545471c..00000000
--- a/openssl/src/opaque.rs
+++ /dev/null
@@ -1,6 +0,0 @@
-use std::cell::UnsafeCell;
-
-/// This is intended to be used as the inner type for types designed to be pointed to by references
-/// converted from raw C pointers. It has an `UnsafeCell` internally to inform the compiler about
-/// aliasability and doesn't implement `Copy`, so it can't be dereferenced.
-pub struct Opaque(UnsafeCell<()>);
diff --git a/openssl/src/pkcs12.rs b/openssl/src/pkcs12.rs
index ab0934a8..1318f7f7 100644
--- a/openssl/src/pkcs12.rs
+++ b/openssl/src/pkcs12.rs
@@ -10,6 +10,7 @@ use {cvt, cvt_p};
 use pkey::PKey;
 use error::ErrorStack;
 use x509::X509;
+use types::OpenSslType;
 
 /// A PKCS #12 archive.
 pub struct Pkcs12(*mut ffi::PKCS12);
diff --git a/openssl/src/pkey.rs b/openssl/src/pkey.rs
index 8e4041b1..6236b642 100644
--- a/openssl/src/pkey.rs
+++ b/openssl/src/pkey.rs
@@ -1,29 +1,19 @@
 use libc::{c_void, c_char, c_int};
 use std::ptr;
 use std::mem;
-use std::ops::Deref;
 use ffi;
 
 use {cvt, cvt_p};
 use bio::{MemBio, MemBioSlice};
 use dsa::Dsa;
-use rsa::{Rsa, RsaRef};
+use rsa::Rsa;
 use error::ErrorStack;
 use util::{CallbackState, invoke_passwd_cb};
-use opaque::Opaque;
+use types::{OpenSslType, Ref};
 
-/// A borrowed `PKey`.
-pub struct PKeyRef(Opaque);
-
-impl PKeyRef {
-    pub unsafe fn from_ptr<'a>(ptr: *mut ffi::EVP_PKEY) -> &'a PKeyRef {
-        &*(ptr as *mut _)
-    }
-
-    pub fn as_ptr(&self) -> *mut ffi::EVP_PKEY {
-        self as *const _ as *mut _
-    }
+type_!(PKey, ffi::EVP_PKEY, ffi::EVP_PKEY_free);
 
+impl Ref<PKey> {
     /// Get a reference to the interal RSA key for direct access to the key components
     pub fn rsa(&self) -> Result<Rsa, ErrorStack> {
         unsafe {
@@ -59,14 +49,11 @@ impl PKeyRef {
         Ok(mem_bio.get_buf().to_owned())
     }
 
-    pub fn public_eq(&self, other: &PKeyRef) -> bool {
+    pub fn public_eq(&self, other: &Ref<PKey>) -> bool {
         unsafe { ffi::EVP_PKEY_cmp(self.as_ptr(), other.as_ptr()) == 1 }
     }
 }
 
-/// Represents a public key, optionally with a private key attached.
-pub struct PKey(*mut ffi::EVP_PKEY);
-
 unsafe impl Send for PKey {}
 unsafe impl Sync for PKey {}
 
@@ -105,10 +92,6 @@ impl PKey {
         }
     }
 
-    pub unsafe fn from_ptr(handle: *mut ffi::EVP_PKEY) -> PKey {
-        PKey(handle)
-    }
-
     /// Reads private key from PEM, takes ownership of handle
     pub fn private_key_from_pem(buf: &[u8]) -> Result<PKey, ErrorStack> {
         ffi::init();
@@ -156,7 +139,7 @@ impl PKey {
     }
 
     /// Assign an RSA key to this pkey.
-    pub fn set_rsa(&mut self, rsa: &RsaRef) -> Result<(), ErrorStack> {
+    pub fn set_rsa(&mut self, rsa: &Ref<Rsa>) -> Result<(), ErrorStack> {
         unsafe {
             // this needs to be a reference as the set1_RSA ups the reference count
             let rsa_ptr = rsa.as_ptr();
@@ -166,22 +149,6 @@ impl PKey {
     }
 }
 
-impl Drop for PKey {
-    fn drop(&mut self) {
-        unsafe {
-            ffi::EVP_PKEY_free(self.0);
-        }
-    }
-}
-
-impl Deref for PKey {
-    type Target = PKeyRef;
-
-    fn deref(&self) -> &PKeyRef {
-        unsafe { PKeyRef::from_ptr(self.0) }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     #[test]
diff --git a/openssl/src/rsa.rs b/openssl/src/rsa.rs
index c6c96223..57a07bd1 100644
--- a/openssl/src/rsa.rs
+++ b/openssl/src/rsa.rs
@@ -2,15 +2,14 @@ use ffi;
 use std::fmt;
 use std::ptr;
 use std::mem;
-use std::ops::Deref;
 use libc::{c_int, c_void, c_char};
 
 use {cvt, cvt_p, cvt_n};
-use bn::{BigNum, BigNumRef};
+use bn::BigNum;
 use bio::{MemBio, MemBioSlice};
 use error::ErrorStack;
 use util::{CallbackState, invoke_passwd_cb};
-use opaque::Opaque;
+use types::{OpenSslType, Ref};
 
 /// Type of encryption padding to use.
 #[derive(Copy, Clone)]
@@ -20,17 +19,9 @@ pub const NO_PADDING: Padding = Padding(ffi::RSA_NO_PADDING);
 pub const PKCS1_PADDING: Padding = Padding(ffi::RSA_PKCS1_PADDING);
 pub const PKCS1_OAEP_PADDING: Padding = Padding(ffi::RSA_PKCS1_OAEP_PADDING);
 
-pub struct RsaRef(Opaque);
-
-impl RsaRef {
-    pub unsafe fn from_ptr<'a>(ptr: *mut ffi::RSA) -> &'a RsaRef {
-        &*(ptr as *mut _)
-    }
-
-    pub fn as_ptr(&self) -> *mut ffi::RSA {
-        self as *const _ as *mut _
-    }
+type_!(Rsa, ffi::RSA, ffi::RSA_free);
 
+impl Ref<Rsa> {
     /// Writes an RSA private key as unencrypted PEM formatted data
     pub fn private_key_to_pem(&self) -> Result<Vec<u8>, ErrorStack> {
         let mem_bio = try!(MemBio::new());
@@ -162,72 +153,62 @@ impl RsaRef {
         }
     }
 
-    pub fn n(&self) -> Option<&BigNumRef> {
+    pub fn n(&self) -> Option<&Ref<BigNum>> {
         unsafe {
             let n = compat::key(self.as_ptr())[0];
             if n.is_null() {
                 None
             } else {
-                Some(BigNumRef::from_ptr(n as *mut _))
+                Some(Ref::<BigNum>::from_ptr(n as *mut _))
             }
         }
     }
 
-    pub fn d(&self) -> Option<&BigNumRef> {
+    pub fn d(&self) -> Option<&Ref<BigNum>> {
         unsafe {
             let d = compat::key(self.as_ptr())[2];
             if d.is_null() {
                 None
             } else {
-                Some(BigNumRef::from_ptr(d as *mut _))
+                Some(Ref::<BigNum>::from_ptr(d as *mut _))
             }
         }
     }
 
-    pub fn e(&self) -> Option<&BigNumRef> {
+    pub fn e(&self) -> Option<&Ref<BigNum>> {
         unsafe {
             let e = compat::key(self.as_ptr())[1];
             if e.is_null() {
                 None
             } else {
-                Some(BigNumRef::from_ptr(e as *mut _))
+                Some(Ref::<BigNum>::from_ptr(e as *mut _))
             }
         }
     }
 
-    pub fn p(&self) -> Option<&BigNumRef> {
+    pub fn p(&self) -> Option<&Ref<BigNum>> {
         unsafe {
             let p = compat::factors(self.as_ptr())[0];
             if p.is_null() {
                 None
             } else {
-                Some(BigNumRef::from_ptr(p as *mut _))
+                Some(Ref::<BigNum>::from_ptr(p as *mut _))
             }
         }
     }
 
-    pub fn q(&self) -> Option<&BigNumRef> {
+    pub fn q(&self) -> Option<&Ref<BigNum>> {
         unsafe {
             let q = compat::factors(self.as_ptr())[1];
             if q.is_null() {
                 None
             } else {
-                Some(BigNumRef::from_ptr(q as *mut _))
+                Some(Ref::<BigNum>::from_ptr(q as *mut _))
             }
         }
     }
 }
 
-pub struct Rsa(*mut ffi::RSA);
-
-impl Drop for Rsa {
-    fn drop(&mut self) {
-        unsafe {
-            ffi::RSA_free(self.0);
-        }
-    }
-}
-
 impl Rsa {
     /// only useful for associating the key material directly with the key, it's safer to use
     /// the supplied load and save methods for DER formatted keys.
@@ -265,10 +246,6 @@ impl Rsa {
         }
     }
 
-    pub unsafe fn from_ptr(rsa: *mut ffi::RSA) -> Rsa {
-        Rsa(rsa)
-    }
-
     /// Generates a public/private key pair with the specified size.
     ///
     /// The public exponent will be 65537.
@@ -329,14 +306,6 @@ impl fmt::Debug for Rsa {
     }
 }
 
-impl Deref for Rsa {
-    type Target = RsaRef;
-
-    fn deref(&self) -> &RsaRef {
-        unsafe { RsaRef::from_ptr(self.0) }
-    }
-}
-
 #[cfg(ossl110)]
 mod compat {
     use std::ptr;
diff --git a/openssl/src/sign.rs b/openssl/src/sign.rs
index eeee5cc7..aebfcca7 100644
--- a/openssl/src/sign.rs
+++ b/openssl/src/sign.rs
@@ -63,13 +63,14 @@ use {cvt, cvt_p};
 use hash::MessageDigest;
 use pkey::PKey;
 use error::ErrorStack;
+use types::Ref;
 
 #[cfg(ossl110)]
 use ffi::{EVP_MD_CTX_new, EVP_MD_CTX_free};
 #[cfg(any(ossl101, ossl102))]
 use ffi::{EVP_MD_CTX_create as EVP_MD_CTX_new, EVP_MD_CTX_destroy as EVP_MD_CTX_free};
 
-pub struct Signer<'a>(*mut ffi::EVP_MD_CTX, PhantomData<&'a PKey>);
+pub struct Signer<'a>(*mut ffi::EVP_MD_CTX, PhantomData<&'a Ref<PKey>>);
 
 impl<'a> Drop for Signer<'a> {
     fn drop(&mut self) {
@@ -80,7 +81,7 @@ impl<'a> Drop for Signer<'a> {
 }
 
 impl<'a> Signer<'a> {
-    pub fn new(type_: MessageDigest, pkey: &'a PKey) -> Result<Signer<'a>, ErrorStack> {
+    pub fn new(type_: MessageDigest, pkey: &'a Ref<PKey>) -> Result<Signer<'a>, ErrorStack> {
         unsafe {
             ffi::init();
 
@@ -128,7 +129,7 @@ impl<'a> Write for Signer<'a> {
     }
 }
 
-pub struct Verifier<'a>(*mut ffi::EVP_MD_CTX, PhantomData<&'a PKey>);
+pub struct Verifier<'a>(*mut ffi::EVP_MD_CTX, PhantomData<&'a Ref<PKey>>);
 
 impl<'a> Drop for Verifier<'a> {
     fn drop(&mut self) {
@@ -139,7 +140,7 @@ impl<'a> Drop for Verifier<'a> {
 }
 
 impl<'a> Verifier<'a> {
-    pub fn new(type_: MessageDigest, pkey: &'a PKey) -> Result<Verifier<'a>, ErrorStack> {
+    pub fn new(type_: MessageDigest, pkey: &'a Ref<PKey>) -> Result<Verifier<'a>, ErrorStack> {
         unsafe {
             ffi::init();
 
diff --git a/openssl/src/ssl/connector.rs b/openssl/src/ssl/connector.rs
index c7bfb209..a1bcfa77 100644
--- a/openssl/src/ssl/connector.rs
+++ b/openssl/src/ssl/connector.rs
@@ -4,8 +4,9 @@ use dh::Dh;
 use error::ErrorStack;
 use ssl::{self, SslMethod, SslContextBuilder, SslContext, Ssl, SSL_VERIFY_PEER, SslStream,
           HandshakeError};
-use pkey::PKeyRef;
-use x509::X509Ref;
+use pkey::PKey;
+use x509::X509;
+use types::Ref;
 
 // apps/dh2048.pem
 const DHPARAM_PEM: &'static str = r#"
@@ -116,12 +117,12 @@ impl SslAcceptorBuilder {
     ///
     /// [docs]: https://wiki.mozilla.org/Security/Server_Side_TLS
     pub fn mozilla_intermediate<I>(method: SslMethod,
-                                   private_key: &PKeyRef,
-                                   certificate: &X509Ref,
+                                   private_key: &Ref<PKey>,
+                                   certificate: &Ref<X509>,
                                    chain: I)
                                    -> Result<SslAcceptorBuilder, ErrorStack>
         where I: IntoIterator,
-              I::Item: AsRef<X509Ref>
+              I::Item: AsRef<Ref<X509>>
     {
         let mut ctx = try!(ctx(method));
         let dh = try!(Dh::from_pem(DHPARAM_PEM.as_bytes()));
@@ -151,12 +152,12 @@ impl SslAcceptorBuilder {
     ///
     /// [docs]: https://wiki.mozilla.org/Security/Server_Side_TLS
     pub fn mozilla_modern<I>(method: SslMethod,
-                             private_key: &PKeyRef,
-                             certificate: &X509Ref,
+                             private_key: &Ref<PKey>,
+                             certificate: &Ref<X509>,
                              chain: I)
                              -> Result<SslAcceptorBuilder, ErrorStack>
         where I: IntoIterator,
-              I::Item: AsRef<X509Ref>
+              I::Item: AsRef<Ref<X509>>
     {
         let mut ctx = try!(ctx(method));
         try!(setup_curves(&mut ctx));
@@ -169,12 +170,12 @@ impl SslAcceptorBuilder {
     }
 
     fn finish_setup<I>(mut ctx: SslContextBuilder,
-                       private_key: &PKeyRef,
-                       certificate: &X509Ref,
+                       private_key: &Ref<PKey>,
+                       certificate: &Ref<X509>,
                        chain: I)
                        -> Result<SslAcceptorBuilder, ErrorStack>
         where I: IntoIterator,
-              I::Item: AsRef<X509Ref>
+              I::Item: AsRef<Ref<X509>>
     {
         try!(ctx.set_private_key(private_key));
         try!(ctx.set_certificate(certificate));
@@ -254,11 +255,12 @@ mod verify {
     use std::net::IpAddr;
 
     use nid;
-    use x509::{X509StoreContextRef, X509Ref, GeneralNames, X509NameRef};
+    use x509::{X509StoreContext, X509, GeneralNames, X509Name};
+    use types::Ref;
 
     pub fn verify_callback(domain: &str,
                            preverify_ok: bool,
-                           x509_ctx: &X509StoreContextRef)
+                           x509_ctx: &Ref<X509StoreContext>)
                            -> bool {
         if !preverify_ok || x509_ctx.error_depth() != 0 {
             return preverify_ok;
@@ -270,7 +272,7 @@ mod verify {
         }
     }
 
-    fn verify_hostname(domain: &str, cert: &X509Ref) -> bool {
+    fn verify_hostname(domain: &str, cert: &Ref<X509>) -> bool {
         match cert.subject_alt_names() {
             Some(names) => verify_subject_alt_names(domain, &names),
             None => verify_subject_name(domain, &cert.subject_name()),
@@ -302,7 +304,7 @@ mod verify {
         false
     }
 
-    fn verify_subject_name(domain: &str, subject_name: &X509NameRef) -> bool {
+    fn verify_subject_name(domain: &str, subject_name: &Ref<X509Name>) -> bool {
         if let Some(pattern) = subject_name.text_by_nid(nid::COMMONNAME) {
             // Unlike with SANs, IP addresses in the subject name don't have a
             // different encoding. We need to pass this down to matches_dns to
diff --git a/openssl/src/ssl/mod.rs b/openssl/src/ssl/mod.rs
index 5466f26e..68d411c7 100644
--- a/openssl/src/ssl/mod.rs
+++ b/openssl/src/ssl/mod.rs
@@ -80,7 +80,6 @@ use std::fmt;
 use std::io;
 use std::io::prelude::*;
 use std::mem;
-use std::ops::{Deref, DerefMut};
 use std::path::Path;
 use std::ptr;
 use std::str;
@@ -91,14 +90,14 @@ use std::marker::PhantomData;
 use ffi;
 
 use {init, cvt, cvt_p};
-use dh::DhRef;
-use ec_key::EcKeyRef;
-use x509::{X509StoreContextRef, X509FileType, X509, X509Ref, X509VerifyError};
+use dh::Dh;
+use ec_key::EcKey;
+use x509::{X509StoreContext, X509FileType, X509, X509VerifyError};
 #[cfg(any(ossl102, ossl110))]
-use verify::X509VerifyParamRef;
-use pkey::PKeyRef;
+use verify::X509VerifyParam;
+use pkey::PKey;
 use error::ErrorStack;
-use opaque::Opaque;
+use types::{OpenSslType, Ref};
 
 mod error;
 mod connector;
@@ -263,7 +262,7 @@ fn get_new_ssl_idx<T>() -> c_int {
 }
 
 extern "C" fn raw_verify<F>(preverify_ok: c_int, x509_ctx: *mut ffi::X509_STORE_CTX) -> c_int
-    where F: Fn(bool, &X509StoreContextRef) -> bool + Any + 'static + Sync + Send
+    where F: Fn(bool, &Ref<X509StoreContext>) -> bool + Any + 'static + Sync + Send
 {
     unsafe {
         let idx = ffi::SSL_get_ex_data_X509_STORE_CTX_idx();
@@ -272,14 +271,14 @@ extern "C" fn raw_verify<F>(preverify_ok: c_int, x509_ctx: *mut ffi::X509_STORE_
         let verify = ffi::SSL_CTX_get_ex_data(ssl_ctx, get_verify_data_idx::<F>());
         let verify: &F = &*(verify as *mut F);
 
-        let ctx = X509StoreContextRef::from_ptr(x509_ctx);
+        let ctx = Ref::from_ptr(x509_ctx);
 
         verify(preverify_ok != 0, ctx) as c_int
     }
 }
 
 extern "C" fn ssl_raw_verify<F>(preverify_ok: c_int, x509_ctx: *mut ffi::X509_STORE_CTX) -> c_int
-    where F: Fn(bool, &X509StoreContextRef) -> bool + Any + 'static + Sync + Send
+    where F: Fn(bool, &Ref<X509StoreContext>) -> bool + Any + 'static + Sync + Send
 {
     unsafe {
         let idx = ffi::SSL_get_ex_data_X509_STORE_CTX_idx();
@@ -287,20 +286,20 @@ extern "C" fn ssl_raw_verify<F>(preverify_ok: c_int, x509_ctx: *mut ffi::X509_ST
         let verify = ffi::SSL_get_ex_data(ssl as *const _, get_ssl_verify_data_idx::<F>());
         let verify: &F = &*(verify as *mut F);
 
-        let ctx = X509StoreContextRef::from_ptr(x509_ctx);
+        let ctx = Ref::from_ptr(x509_ctx);
 
         verify(preverify_ok != 0, ctx) as c_int
     }
 }
 
 extern "C" fn raw_sni<F>(ssl: *mut ffi::SSL, al: *mut c_int, _arg: *mut c_void) -> c_int
-    where F: Fn(&mut SslRef) -> Result<(), SniError> + Any + 'static + Sync + Send
+    where F: Fn(&mut Ref<Ssl>) -> Result<(), SniError> + Any + 'static + Sync + Send
 {
     unsafe {
         let ssl_ctx = ffi::SSL_get_SSL_CTX(ssl);
         let callback = ffi::SSL_CTX_get_ex_data(ssl_ctx, get_verify_data_idx::<F>());
         let callback: &F = &*(callback as *mut F);
-        let ssl = SslRef::from_ptr_mut(ssl);
+        let ssl = Ref::from_ptr_mut(ssl);
 
         match callback(ssl) {
             Ok(()) => ffi::SSL_TLSEXT_ERR_OK,
@@ -464,7 +463,7 @@ impl SslContextBuilder {
     /// Configures the certificate verification method for new connections and
     /// registers a verification callback.
     pub fn set_verify_callback<F>(&mut self, mode: SslVerifyMode, verify: F)
-        where F: Fn(bool, &X509StoreContextRef) -> bool + Any + 'static + Sync + Send
+        where F: Fn(bool, &Ref<X509StoreContext>) -> bool + Any + 'static + Sync + Send
     {
         unsafe {
             let verify = Box::new(verify);
@@ -480,7 +479,7 @@ impl SslContextBuilder {
     /// Obtain the server name with `servername` then set the corresponding context
     /// with `set_ssl_context`
     pub fn set_servername_callback<F>(&mut self, callback: F)
-        where F: Fn(&mut SslRef) -> Result<(), SniError> + Any + 'static + Sync + Send
+        where F: Fn(&mut Ref<Ssl>) -> Result<(), SniError> + Any + 'static + Sync + Send
     {
         unsafe {
             let callback = Box::new(callback);
@@ -513,11 +512,11 @@ impl SslContextBuilder {
         }
     }
 
-    pub fn set_tmp_dh(&mut self, dh: &DhRef) -> Result<(), ErrorStack> {
+    pub fn set_tmp_dh(&mut self, dh: &Ref<Dh>) -> Result<(), ErrorStack> {
         unsafe { cvt(ffi::SSL_CTX_set_tmp_dh(self.as_ptr(), dh.as_ptr()) as c_int).map(|_| ()) }
     }
 
-    pub fn set_tmp_ecdh(&mut self, key: &EcKeyRef) -> Result<(), ErrorStack> {
+    pub fn set_tmp_ecdh(&mut self, key: &Ref<EcKey>) -> Result<(), ErrorStack> {
         unsafe { cvt(ffi::SSL_CTX_set_tmp_ecdh(self.as_ptr(), key.as_ptr()) as c_int).map(|_| ()) }
     }
 
@@ -585,7 +584,7 @@ impl SslContextBuilder {
     }
 
     /// Specifies the certificate
-    pub fn set_certificate(&mut self, cert: &X509Ref) -> Result<(), ErrorStack> {
+    pub fn set_certificate(&mut self, cert: &Ref<X509>) -> Result<(), ErrorStack> {
         unsafe { cvt(ffi::SSL_CTX_use_certificate(self.as_ptr(), cert.as_ptr())).map(|_| ()) }
     }
 
@@ -614,7 +613,7 @@ impl SslContextBuilder {
     }
 
     /// Specifies the private key
-    pub fn set_private_key(&mut self, key: &PKeyRef) -> Result<(), ErrorStack> {
+    pub fn set_private_key(&mut self, key: &Ref<PKey>) -> Result<(), ErrorStack> {
         unsafe { cvt(ffi::SSL_CTX_use_PrivateKey(self.as_ptr(), key.as_ptr())).map(|_| ()) }
     }
 
@@ -734,25 +733,7 @@ impl SslContextBuilder {
     }
 }
 
-/// A borrowed SSL context object.
-pub struct SslContextRef(Opaque);
-
-impl SslContextRef {
-    pub unsafe fn from_ptr<'a>(ctx: *mut ffi::SSL_CTX) -> &'a SslContextRef {
-        &*(ctx as *mut _)
-    }
-
-    pub unsafe fn from_ptr_mut<'a>(ctx: *mut ffi::SSL_CTX) -> &'a mut SslContextRef {
-        &mut *(ctx as *mut _)
-    }
-
-    pub fn as_ptr(&self) -> *mut ffi::SSL_CTX {
-        self as *const _ as *mut _
-    }
-}
-
-/// An owned SSL context object.
-pub struct SslContext(*mut ffi::SSL_CTX);
+type_!(SslContext, ffi::SSL_CTX, ffi::SSL_CTX_free);
 
 unsafe impl Send for SslContext {}
 unsafe impl Sync for SslContext {}
@@ -773,38 +754,10 @@ impl fmt::Debug for SslContext {
     }
 }
 
-impl Drop for SslContext {
-    fn drop(&mut self) {
-        unsafe { ffi::SSL_CTX_free(self.as_ptr()) }
-    }
-}
-
-impl Deref for SslContext {
-    type Target = SslContextRef;
-
-    fn deref(&self) -> &SslContextRef {
-        unsafe { SslContextRef::from_ptr(self.0) }
-    }
-}
-
-impl DerefMut for SslContext {
-    fn deref_mut(&mut self) -> &mut SslContextRef {
-        unsafe { SslContextRef::from_ptr_mut(self.0) }
-    }
-}
-
 impl SslContext {
     pub fn builder(method: SslMethod) -> Result<SslContextBuilder, ErrorStack> {
         SslContextBuilder::new(method)
     }
-
-    pub unsafe fn from_ptr(ctx: *mut ffi::SSL_CTX) -> SslContext {
-        SslContext(ctx)
-    }
-
-    pub fn as_ptr(&self) -> *mut ffi::SSL_CTX {
-        self.0
-    }
 }
 
 
@@ -816,17 +769,21 @@ pub struct CipherBits {
     pub algorithm: i32,
 }
 
-pub struct SslCipherRef(Opaque);
+pub struct SslCipher(*mut ffi::SSL_CIPHER);
+
+unsafe impl OpenSslType for SslCipher {
+    type CType = ffi::SSL_CIPHER;
 
-impl SslCipherRef {
-    pub unsafe fn from_ptr<'a>(ptr: *const ffi::SSL_CIPHER) -> &'a SslCipherRef {
-        &*(ptr as *const _)
+    unsafe fn from_ptr(ptr: *mut ffi::SSL_CIPHER) -> SslCipher {
+        SslCipher(ptr)
     }
 
-    pub fn as_ptr(&self) -> *const ffi::SSL_CIPHER {
-        self as *const _ as *const _
+    fn as_ptr(&self) -> *mut ffi::SSL_CIPHER {
+        self.0
     }
+}
 
+impl Ref<SslCipher> {
     /// Returns the name of cipher.
     pub fn name(&self) -> &'static str {
         let name = unsafe {
@@ -870,15 +827,11 @@ impl SslCipherRef {
     }
 }
 
-/// A reference to an `Ssl`.
-pub struct SslRef(Opaque);
-
-unsafe impl Send for SslRef {}
-unsafe impl Sync for SslRef {}
+type_!(Ssl, ffi::SSL, ffi::SSL_free);
 
-impl fmt::Debug for SslRef {
+impl fmt::Debug for Ref<Ssl> {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-        let mut builder = fmt.debug_struct("SslRef");
+        let mut builder = fmt.debug_struct("Ssl");
         builder.field("state", &self.state_string_long());
         if let Some(err) = self.verify_result() {
             builder.field("verify_result", &err);
@@ -887,19 +840,7 @@ impl fmt::Debug for SslRef {
     }
 }
 
-impl SslRef {
-    pub unsafe fn from_ptr<'a>(ssl: *mut ffi::SSL) -> &'a SslRef {
-        &*(ssl as *mut _)
-    }
-
-    pub unsafe fn from_ptr_mut<'a>(ssl: *mut ffi::SSL) -> &'a mut SslRef {
-        &mut *(ssl as *mut _)
-    }
-
-    pub fn as_ptr(&self) -> *mut ffi::SSL {
-        self as *const _ as *mut _
-    }
-
+impl Ref<Ssl> {
     fn get_raw_rbio(&self) -> *mut ffi::BIO {
         unsafe { ffi::SSL_get_rbio(self.as_ptr()) }
     }
@@ -933,7 +874,7 @@ impl SslRef {
     /// to the certificate chain. It should return `true` if the certificate
     /// chain is valid and `false` otherwise.
     pub fn set_verify_callback<F>(&mut self, mode: SslVerifyMode, verify: F)
-        where F: Fn(bool, &X509StoreContextRef) -> bool + Any + 'static + Sync + Send
+        where F: Fn(bool, &Ref<X509StoreContext>) -> bool + Any + 'static + Sync + Send
     {
         unsafe {
             let verify = Box::new(verify);
@@ -944,14 +885,14 @@ impl SslRef {
         }
     }
 
-    pub fn current_cipher(&self) -> Option<&SslCipherRef> {
+    pub fn current_cipher(&self) -> Option<&Ref<SslCipher>> {
         unsafe {
             let ptr = ffi::SSL_get_current_cipher(self.as_ptr());
 
             if ptr.is_null() {
                 None
             } else {
-                Some(SslCipherRef::from_ptr(ptr))
+                Some(Ref::from_ptr(ptr as *mut _))
             }
         }
     }
@@ -1092,15 +1033,15 @@ impl SslRef {
     }
 
     /// Changes the context corresponding to the current connection.
-    pub fn set_ssl_context(&mut self, ctx: &SslContextRef) -> Result<(), ErrorStack> {
+    pub fn set_ssl_context(&mut self, ctx: &Ref<SslContext>) -> Result<(), ErrorStack> {
         unsafe { cvt_p(ffi::SSL_set_SSL_CTX(self.as_ptr(), ctx.as_ptr())).map(|_| ()) }
     }
 
     /// Returns the context corresponding to the current connection
-    pub fn ssl_context(&self) -> &SslContextRef {
+    pub fn ssl_context(&self) -> &Ref<SslContext> {
         unsafe {
             let ssl_ctx = ffi::SSL_get_SSL_CTX(self.as_ptr());
-            SslContextRef::from_ptr(ssl_ctx)
+            Ref::from_ptr(ssl_ctx)
         }
     }
 
@@ -1108,13 +1049,13 @@ impl SslRef {
     ///
     /// Requires the `v102` or `v110` features and OpenSSL 1.0.2 or 1.1.0.
     #[cfg(any(all(feature = "v102", ossl102), all(feature = "v110", ossl110)))]
-    pub fn param_mut(&mut self) -> &mut X509VerifyParamRef {
+    pub fn param_mut(&mut self) -> &mut Ref<X509VerifyParam> {
         self._param_mut()
     }
 
     #[cfg(any(ossl102, ossl110))]
-    fn _param_mut(&mut self) -> &mut X509VerifyParamRef {
-        unsafe { X509VerifyParamRef::from_ptr_mut(ffi::SSL_get0_param(self.as_ptr())) }
+    fn _param_mut(&mut self) -> &mut Ref<X509VerifyParam> {
+        unsafe { Ref::from_ptr_mut(ffi::SSL_get0_param(self.as_ptr())) }
     }
 
     /// Returns the result of X509 certificate verification.
@@ -1123,39 +1064,12 @@ impl SslRef {
     }
 }
 
-pub struct Ssl(*mut ffi::SSL);
-
 unsafe impl Sync for Ssl {}
 unsafe impl Send for Ssl {}
 
 impl fmt::Debug for Ssl {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-        let mut builder = fmt.debug_struct("Ssl");
-        builder.field("state", &self.state_string_long());
-        if let Some(err) = self.verify_result() {
-            builder.field("verify_result", &err);
-        }
-        builder.finish()
-    }
-}
-
-impl Drop for Ssl {
-    fn drop(&mut self) {
-        unsafe { ffi::SSL_free(self.as_ptr()) }
-    }
-}
-
-impl Deref for Ssl {
-    type Target = SslRef;
-
-    fn deref(&self) -> &SslRef {
-        unsafe { SslRef::from_ptr(self.0) }
-    }
-}
-
-impl DerefMut for Ssl {
-    fn deref_mut(&mut self) -> &mut SslRef {
-        unsafe { SslRef::from_ptr_mut(self.0) }
+        fmt::Debug::fmt(&**self, fmt)
     }
 }
 
@@ -1167,10 +1081,6 @@ impl Ssl {
         }
     }
 
-    pub unsafe fn from_ptr(ssl: *mut ffi::SSL) -> Ssl {
-        Ssl(ssl)
-    }
-
     /// Creates an SSL/TLS client operating over the provided stream.
     ///
     /// # Warning
@@ -1255,7 +1165,7 @@ impl<S> MidHandshakeSslStream<S> {
     }
 
     /// Returns a shared reference to the `Ssl` of the stream.
-    pub fn ssl(&self) -> &SslRef {
+    pub fn ssl(&self) -> &Ref<Ssl> {
         self.stream.ssl()
     }
 
@@ -1437,7 +1347,7 @@ impl<S> SslStream<S> {
     }
 
     /// Returns the OpenSSL `Ssl` object associated with this stream.
-    pub fn ssl(&self) -> &SslRef {
+    pub fn ssl(&self) -> &Ref<Ssl> {
         &self.ssl
     }
 }
diff --git a/openssl/src/ssl/tests/mod.rs b/openssl/src/ssl/tests/mod.rs
index a874fe3b..13b3a8a7 100644
--- a/openssl/src/ssl/tests/mod.rs
+++ b/openssl/src/ssl/tests/mod.rs
@@ -20,7 +20,7 @@ use ssl::SSL_VERIFY_PEER;
 use ssl::{SslMethod, HandshakeError};
 use ssl::{SslContext, SslStream, Ssl, ShutdownResult, SslConnectorBuilder, SslAcceptorBuilder,
           Error};
-use x509::X509StoreContextRef;
+use x509::X509StoreContext;
 use x509::X509FileType;
 use x509::X509;
 #[cfg(any(all(feature = "v102", ossl102), all(feature = "v110", ossl110)))]
@@ -171,8 +171,9 @@ macro_rules! run_test(
             use ssl::{SslContext, Ssl, SslStream};
             use ssl::SSL_VERIFY_PEER;
             use hash::MessageDigest;
-            use x509::X509StoreContextRef;
+            use x509::X509StoreContext;
             use serialize::hex::FromHex;
+            use types::Ref;
             use super::Server;
 
             #[test]
@@ -771,24 +772,6 @@ fn test_alpn_server_select_none() {
     assert!(Ssl::new(&ctx.build()).unwrap().connect(stream).is_err());
 }
 
-#[cfg(test)]
-mod dtlsv1 {
-    use serialize::hex::FromHex;
-    use std::net::TcpStream;
-    use std::thread;
-
-    use hash::MessageDigest;
-    use ssl::SslMethod;
-    use ssl::{SslContext, SslStream};
-    use ssl::SSL_VERIFY_PEER;
-    use x509::X509StoreContextRef;
-
-    #[test]
-    fn test_new_ctx() {
-        SslContext::builder(SslMethod::dtls()).unwrap();
-    }
-}
-
 #[test]
 #[cfg_attr(any(windows, target_arch = "arm"), ignore)] // FIXME(#467)
 fn test_read_dtlsv1() {
diff --git a/openssl/src/types.rs b/openssl/src/types.rs
new file mode 100644
index 00000000..40831ee8
--- /dev/null
+++ b/openssl/src/types.rs
@@ -0,0 +1,39 @@
+//! Items used by other types.
+
+use std::cell::UnsafeCell;
+use std::marker::PhantomData;
+
+/// A type implemented by wrappers over OpenSSL types.
+///
+/// This should not be implemented by anything outside of this crate; new methods may be added at
+/// any time.
+pub unsafe trait OpenSslType {
+    /// The raw C type.
+    type CType;
+
+    /// Constructs an instance of this type from its raw type.
+    unsafe fn from_ptr(ptr: *mut Self::CType) -> Self;
+
+    /// Returns a pointer to its raw type.
+    fn as_ptr(&self) -> *mut Self::CType;
+}
+
+/// A reference to an OpenSSL type.
+pub struct Ref<T>(UnsafeCell<()>, PhantomData<T>);
+
+impl<T: OpenSslType> Ref<T> {
+    /// Constructs a shared reference to this type from its raw type.
+    pub unsafe fn from_ptr<'a>(ptr: *mut T::CType) -> &'a Ref<T> {
+        &*(ptr as *mut _)
+    }
+
+    /// Constructs a mutable reference to this type from its raw type.
+    pub unsafe fn from_ptr_mut<'a>(ptr: *mut T::CType) -> &'a mut Ref<T> {
+        &mut *(ptr as *mut _)
+    }
+
+    /// Returns a pointer to its raw type.
+    pub fn as_ptr(&self) -> *mut T::CType {
+        self as *const _ as *mut _
+    }
+}
diff --git a/openssl/src/verify.rs b/openssl/src/verify.rs
index ceb3a6c8..c067e08e 100644
--- a/openssl/src/verify.rs
+++ b/openssl/src/verify.rs
@@ -3,7 +3,7 @@ use ffi;
 
 use cvt;
 use error::ErrorStack;
-use opaque::Opaque;
+use types::Ref;
 
 bitflags! {
     pub flags X509CheckFlags: c_uint {
@@ -19,17 +19,9 @@ bitflags! {
     }
 }
 
-pub struct X509VerifyParamRef(Opaque);
-
-impl X509VerifyParamRef {
-    pub unsafe fn from_ptr_mut<'a>(ptr: *mut ffi::X509_VERIFY_PARAM) -> &'a mut X509VerifyParamRef {
-        &mut *(ptr as *mut _)
-    }
-
-    pub fn as_ptr(&self) -> *mut ffi::X509_VERIFY_PARAM {
-        self as *const _ as *mut _
-    }
+type_!(X509VerifyParam, ffi::X509_VERIFY_PARAM, ffi::X509_VERIFY_PARAM_free);
 
+impl Ref<X509VerifyParam> {
     pub fn set_hostflags(&mut self, hostflags: X509CheckFlags) {
         unsafe {
             ffi::X509_VERIFY_PARAM_set_hostflags(self.as_ptr(), hostflags.bits);
diff --git a/openssl/src/x509/mod.rs b/openssl/src/x509/mod.rs
index b49a9848..bb2c7544 100644
--- a/openssl/src/x509/mod.rs
+++ b/openssl/src/x509/mod.rs
@@ -7,23 +7,21 @@ use std::ffi::{CStr, CString};
 use std::fmt;
 use std::marker::PhantomData;
 use std::mem;
-use std::ops::Deref;
 use std::ptr;
 use std::slice;
 use std::str;
 
 use {cvt, cvt_p};
 use asn1::Asn1Time;
-use asn1::Asn1TimeRef;
 use bio::{MemBio, MemBioSlice};
 use crypto::CryptoString;
 use hash::MessageDigest;
-use pkey::{PKey, PKeyRef};
+use pkey::PKey;
 use rand::rand_bytes;
 use error::ErrorStack;
 use ffi;
 use nid::Nid;
-use opaque::Opaque;
+use types::{OpenSslType, Ref};
 
 #[cfg(ossl10x)]
 use ffi::{X509_set_notBefore, X509_set_notAfter, ASN1_STRING_data};
@@ -49,28 +47,20 @@ pub enum X509FileType {
     Default = ffi::X509_FILETYPE_DEFAULT,
 }
 
-pub struct X509StoreContextRef(Opaque);
-
-impl X509StoreContextRef {
-    pub unsafe fn from_ptr<'a>(ctx: *mut ffi::X509_STORE_CTX) -> &'a X509StoreContextRef {
-        &*(ctx as *mut _)
-    }
-
-    pub fn as_ptr(&self) -> *mut ffi::X509_STORE_CTX {
-        self as *const _ as *mut _
-    }
+type_!(X509StoreContext, ffi::X509_STORE_CTX, ffi::X509_STORE_CTX_free);
 
+impl Ref<X509StoreContext> {
     pub fn error(&self) -> Option<X509VerifyError> {
         unsafe { X509VerifyError::from_raw(ffi::X509_STORE_CTX_get_error(self.as_ptr()) as c_long) }
     }
 
-    pub fn current_cert(&self) -> Option<&X509Ref> {
+    pub fn current_cert(&self) -> Option<&Ref<X509>> {
         unsafe {
             let ptr = ffi::X509_STORE_CTX_get_current_cert(self.as_ptr());
             if ptr.is_null() {
                 None
             } else {
-                Some(X509Ref::from_ptr(ptr))
+                Some(Ref::from_ptr(ptr))
             }
         }
     }
@@ -269,7 +259,7 @@ impl X509Generator {
     }
 
     /// Sets the certificate public-key, then self-sign and return it
-    pub fn sign(&self, p_key: &PKeyRef) -> Result<X509, ErrorStack> {
+    pub fn sign(&self, p_key: &Ref<PKey>) -> Result<X509, ErrorStack> {
         ffi::init();
 
         unsafe {
@@ -321,7 +311,7 @@ impl X509Generator {
     }
 
     /// Obtain a certificate signing request (CSR)
-    pub fn request(&self, p_key: &PKeyRef) -> Result<X509Req, ErrorStack> {
+    pub fn request(&self, p_key: &Ref<PKey>) -> Result<X509Req, ErrorStack> {
         let cert = match self.sign(p_key) {
             Ok(c) => c,
             Err(x) => return Err(x),
@@ -346,23 +336,13 @@ impl X509Generator {
     }
 }
 
-/// A borrowed public key certificate.
-pub struct X509Ref(Opaque);
-
-impl X509Ref {
-    /// Creates a new `X509Ref` wrapping the provided handle.
-    pub unsafe fn from_ptr<'a>(x509: *mut ffi::X509) -> &'a X509Ref {
-        &*(x509 as *mut _)
-    }
-
-    pub fn as_ptr(&self) -> *mut ffi::X509 {
-        self as *const _ as *mut _
-    }
+type_!(X509, ffi::X509, ffi::X509_free);
 
-    pub fn subject_name(&self) -> &X509NameRef {
+impl Ref<X509> {
+    pub fn subject_name(&self) -> &Ref<X509Name> {
         unsafe {
             let name = ffi::X509_get_subject_name(self.as_ptr());
-            X509NameRef::from_ptr(name)
+            Ref::from_ptr(name)
         }
     }
 
@@ -401,20 +381,20 @@ impl X509Ref {
     }
 
     /// Returns certificate Not After validity period.
-    pub fn not_after<'a>(&'a self) -> &'a Asn1TimeRef {
+    pub fn not_after<'a>(&'a self) -> &'a Ref<Asn1Time> {
         unsafe {
             let date = compat::X509_get_notAfter(self.as_ptr());
             assert!(!date.is_null());
-            Asn1TimeRef::from_ptr(date)
+            Ref::from_ptr(date)
         }
     }
 
     /// Returns certificate Not Before validity period.
-    pub fn not_before<'a>(&'a self) -> &'a Asn1TimeRef {
+    pub fn not_before<'a>(&'a self) -> &'a Ref<Asn1Time> {
         unsafe {
             let date = compat::X509_get_notBefore(self.as_ptr());
             assert!(!date.is_null());
-            Asn1TimeRef::from_ptr(date)
+            Ref::from_ptr(date)
         }
     }
 
@@ -437,7 +417,7 @@ impl X509Ref {
     }
 }
 
-impl ToOwned for X509Ref {
+impl ToOwned for Ref<X509> {
     type Owned = X509;
 
     fn to_owned(&self) -> X509 {
@@ -448,15 +428,7 @@ impl ToOwned for X509Ref {
     }
 }
 
-/// An owned public key certificate.
-pub struct X509(*mut ffi::X509);
-
 impl X509 {
-    /// Returns a new `X509`, taking ownership of the handle.
-    pub unsafe fn from_ptr(x509: *mut ffi::X509) -> X509 {
-        X509(x509)
-    }
-
     /// Reads a certificate from DER.
     pub fn from_der(buf: &[u8]) -> Result<X509, ErrorStack> {
         unsafe {
@@ -480,49 +452,27 @@ impl X509 {
     }
 }
 
-impl Deref for X509 {
-    type Target = X509Ref;
-
-    fn deref(&self) -> &X509Ref {
-        unsafe { X509Ref::from_ptr(self.0) }
-    }
-}
-
 impl Clone for X509 {
     fn clone(&self) -> X509 {
         self.to_owned()
     }
 }
 
-impl Drop for X509 {
-    fn drop(&mut self) {
-        unsafe { ffi::X509_free(self.as_ptr()) };
-    }
-}
-
-impl AsRef<X509Ref> for X509 {
-    fn as_ref(&self) -> &X509Ref {
+impl AsRef<Ref<X509>> for X509 {
+    fn as_ref(&self) -> &Ref<X509> {
         &*self
     }
 }
 
-impl Borrow<X509Ref> for X509 {
-    fn borrow(&self) -> &X509Ref {
+impl Borrow<Ref<X509>> for X509 {
+    fn borrow(&self) -> &Ref<X509> {
         &*self
     }
 }
 
-pub struct X509NameRef(Opaque);
-
-impl X509NameRef {
-    pub unsafe fn from_ptr<'a>(ptr: *mut ffi::X509_NAME) -> &'a X509NameRef {
-        &*(ptr as *mut _)
-    }
-
-    pub fn as_ptr(&self) -> *mut ffi::X509_NAME {
-        self as *const _ as *mut _
-    }
+type_!(X509Name, ffi::X509_NAME, ffi::X509_NAME_free);
 
+impl Ref<X509Name> {
     pub fn text_by_nid(&self, nid: Nid) -> Option<CryptoString> {
         unsafe {
             let loc = ffi::X509_NAME_get_index_by_NID(self.as_ptr(), nid.as_raw(), -1);
@@ -554,34 +504,13 @@ impl X509NameRef {
     }
 }
 
-/// A certificate signing request
-pub struct X509Req(*mut ffi::X509_REQ);
-
-impl X509Req {
-    pub unsafe fn from_ptr(handle: *mut ffi::X509_REQ) -> X509Req {
-        X509Req(handle)
-    }
-
-    pub fn as_ptr(&self) -> *mut ffi::X509_REQ {
-        self.0
-    }
-
-    /// Reads CSR from PEM
-    pub fn from_pem(buf: &[u8]) -> Result<X509Req, ErrorStack> {
-        let mem_bio = try!(MemBioSlice::new(buf));
-        unsafe {
-            let handle = try!(cvt_p(ffi::PEM_read_bio_X509_REQ(mem_bio.as_ptr(),
-                                                               ptr::null_mut(),
-                                                               None,
-                                                               ptr::null_mut())));
-            Ok(X509Req::from_ptr(handle))
-        }
-    }
+type_!(X509Req, ffi::X509_REQ, ffi::X509_REQ_free);
 
+impl Ref<X509Req> {
     /// Writes CSR as PEM
     pub fn to_pem(&self) -> Result<Vec<u8>, ErrorStack> {
         let mem_bio = try!(MemBio::new());
-        if unsafe { ffi::PEM_write_bio_X509_REQ(mem_bio.as_ptr(), self.0) } != 1 {
+        if unsafe { ffi::PEM_write_bio_X509_REQ(mem_bio.as_ptr(), self.as_ptr()) } != 1 {
             return Err(ErrorStack::get());
         }
         Ok(mem_bio.get_buf().to_owned())
@@ -591,15 +520,23 @@ impl X509Req {
     pub fn to_der(&self) -> Result<Vec<u8>, ErrorStack> {
         let mem_bio = try!(MemBio::new());
         unsafe {
-            ffi::i2d_X509_REQ_bio(mem_bio.as_ptr(), self.0);
+            ffi::i2d_X509_REQ_bio(mem_bio.as_ptr(), self.as_ptr());
         }
         Ok(mem_bio.get_buf().to_owned())
     }
 }
 
-impl Drop for X509Req {
-    fn drop(&mut self) {
-        unsafe { ffi::X509_REQ_free(self.0) };
+impl X509Req {
+    /// Reads CSR from PEM
+    pub fn from_pem(buf: &[u8]) -> Result<X509Req, ErrorStack> {
+        let mem_bio = try!(MemBioSlice::new(buf));
+        unsafe {
+            let handle = try!(cvt_p(ffi::PEM_read_bio_X509_REQ(mem_bio.as_ptr(),
+                                                               ptr::null_mut(),
+                                                               None,
+                                                               ptr::null_mut())));
+            Ok(X509Req::from_ptr(handle))
+        }
     }
 }