Support public key decode from DER

Closes #629

openssl-sys/src/lib.rs

@@ -2014,6 +2014,7 @@ extern {
     pub fn i2d_X509_REQ_bio(b: *mut BIO, x: *mut X509_REQ) -> c_int;
     pub fn i2d_X509_REQ(x: *mut X509_REQ, buf: *mut *mut u8) -> c_int;
 
+    pub fn d2i_PUBKEY(k: *mut *mut EVP_PKEY, buf: *mut *const u8, len: c_long) -> *mut EVP_PKEY;
     pub fn i2d_PUBKEY_bio(b: *mut BIO, x: *mut EVP_PKEY) -> c_int;
     pub fn i2d_PrivateKey_bio(b: *mut BIO, x: *mut EVP_PKEY) -> c_int;
     pub fn i2d_PUBKEY(k: *mut EVP_PKEY, buf: *mut *mut u8) -> c_int;

openssl/src/pkey.rs

@@ -140,6 +140,7 @@ impl PKey {
 
     private_key_from_pem!(PKey, ffi::PEM_read_bio_PrivateKey);
     public_key_from_pem!(PKey, ffi::PEM_read_bio_PUBKEY);
+    public_key_from_der!(PKey, ffi::d2i_PUBKEY);
 
     /// Deserializes a DER-formatted PKCS#8 private key, using a callback to retrieve the password
     /// if the key is encrpyted.
@@ -310,6 +311,12 @@ mod tests {
         PKey::public_key_from_pem(key).unwrap();
     }
 
+    #[test]
+    fn test_public_key_from_der() {
+        let key = include_bytes!("../test/key.der.pub");
+        PKey::public_key_from_der(key).unwrap();
+    }
+
     #[test]
     fn test_pem() {
         let key = include_bytes!("../test/key.pem");