From 9ea27c12b9b5d2d723d8686f5bde4de0223cb160 Mon Sep 17 00:00:00 2001
From: Lionel Flandrin <lionel@svkt.org>
Date: Tue, 1 Nov 2016 11:55:02 +0100
Subject: [PATCH] Add method to encode a public key as a DER blob

---
 openssl-sys/src/lib.rs |  2 ++
 openssl/src/pkey.rs    | 11 ++++++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/openssl-sys/src/lib.rs b/openssl-sys/src/lib.rs
index f556b19f..1a9a2ac1 100644
--- a/openssl-sys/src/lib.rs
+++ b/openssl-sys/src/lib.rs
@@ -1693,6 +1693,8 @@ extern {
     pub fn i2d_X509_bio(b: *mut BIO, x: *mut X509) -> c_int;
     pub fn i2d_X509_REQ_bio(b: *mut BIO, x: *mut X509_REQ) -> c_int;
 
+    pub fn i2d_PUBKEY_bio(b: *mut BIO, x: *mut EVP_PKEY) -> c_int;
+
     pub fn i2d_RSA_PUBKEY(k: *mut RSA, buf: *mut *mut u8) -> c_int;
     pub fn d2i_RSA_PUBKEY(k: *mut *mut RSA, buf: *mut *const u8, len: c_long) -> *mut RSA;
     pub fn i2d_RSAPrivateKey(k: *const RSA, buf: *mut *mut u8) -> c_int;
diff --git a/openssl/src/pkey.rs b/openssl/src/pkey.rs
index 6236b642..4885ad3c 100644
--- a/openssl/src/pkey.rs
+++ b/openssl/src/pkey.rs
@@ -40,7 +40,7 @@ impl Ref<PKey> {
         Ok(mem_bio.get_buf().to_owned())
     }
 
-    /// Stores public key as a PEM
+    /// Encode public key in PEM format
     pub fn public_key_to_pem(&self) -> Result<Vec<u8>, ErrorStack> {
         let mem_bio = try!(MemBio::new());
         unsafe {
@@ -49,6 +49,15 @@ impl Ref<PKey> {
         Ok(mem_bio.get_buf().to_owned())
     }
 
+    /// Encode public key in DER format
+    pub fn public_key_to_der(&self) -> Result<Vec<u8>, ErrorStack> {
+        let mem_bio = try!(MemBio::new());
+        unsafe {
+            try!(cvt(ffi::i2d_PUBKEY_bio(mem_bio.as_ptr(), self.as_ptr())));
+        }
+        Ok(mem_bio.get_buf().to_owned())
+    }
+
     pub fn public_eq(&self, other: &Ref<PKey>) -> bool {
         unsafe { ffi::EVP_PKEY_cmp(self.as_ptr(), other.as_ptr()) == 1 }
     }