diff --git a/openssl-sys/src/lib.rs b/openssl-sys/src/lib.rs
index d18fa5ad..37921021 100644
--- a/openssl-sys/src/lib.rs
+++ b/openssl-sys/src/lib.rs
@@ -26,6 +26,7 @@ pub use libressl::*;
 pub enum ASN1_INTEGER {}
 pub enum ASN1_GENERALIZEDTIME {}
 pub enum ASN1_STRING {}
+pub enum ASN1_BIT_STRING {}
 pub enum ASN1_TIME {}
 pub enum ASN1_TYPE {}
 pub enum BN_CTX {}
@@ -1408,6 +1409,7 @@ extern {
     pub fn ASN1_STRING_type_new(ty: c_int) -> *mut ASN1_STRING;
     pub fn ASN1_TIME_free(tm: *mut ASN1_TIME);
     pub fn ASN1_TIME_print(b: *mut BIO, tm: *const ASN1_TIME) -> c_int;
+    pub fn ASN1_BIT_STRING_free(x: *mut ASN1_BIT_STRING);
 
     pub fn BIO_ctrl(b: *mut BIO, cmd: c_int, larg: c_long, parg: *mut c_void) -> c_long;
     pub fn BIO_free_all(b: *mut BIO);
diff --git a/openssl/src/asn1.rs b/openssl/src/asn1.rs
index fd932723..0ba54440 100644
--- a/openssl/src/asn1.rs
+++ b/openssl/src/asn1.rs
@@ -93,6 +93,24 @@ impl Asn1StringRef {
     }
 }
 
+foreign_type! {
+    type CType = ffi::ASN1_BIT_STRING;
+    fn drop = ffi::ASN1_BIT_STRING_free;
+
+    pub struct Asn1BitString;
+    pub struct Asn1BitStringRef;
+}
+
+impl Asn1BitStringRef {
+    pub fn as_slice(&self) -> &[u8] {
+        unsafe { slice::from_raw_parts(ASN1_STRING_data(self.as_ptr() as *mut _), self.len()) }
+    }
+
+    pub fn len(&self) -> usize {
+        unsafe { ffi::ASN1_STRING_length(self.as_ptr() as *mut _) as usize }
+    }
+}
+
 #[cfg(any(ossl101, ossl102))]
 use ffi::ASN1_STRING_data;