Support serialization of encrypted private keys

Switch to PEM_write_bio_PKCS8PrivateKey since the other function outputs
nonstandard PEM when encrypting.

openssl-sys/src/lib.rs

@@ -1496,6 +1496,10 @@ extern {
                                     kstr: *mut c_uchar, klen: c_int,
                                     callback: Option<PasswordCallback>,
                                     user_data: *mut c_void) -> c_int;
+    pub fn PEM_write_bio_PKCS8PrivateKey(bio: *mut BIO, pkey: *mut EVP_PKEY, cipher: *const EVP_CIPHER,
+                                        kstr: *mut c_char, klen: c_int,
+                                        callback: Option<PasswordCallback>,
+                                        user_data: *mut c_void) -> c_int;
     pub fn PEM_write_bio_PUBKEY(bp: *mut BIO, x: *mut EVP_PKEY) -> c_int;
     pub fn PEM_write_bio_RSAPrivateKey(bp: *mut BIO, rsa: *mut RSA, cipher: *const EVP_CIPHER,
                                         kstr: *mut c_uchar, klen: c_int,

openssl/src/dsa.rs

@@ -207,6 +207,8 @@ mod compat {
 
 #[cfg(test)]
 mod test {
+    use symm::Cipher;
+
     use super::*;
 
     #[test]
@@ -220,6 +222,14 @@ mod test {
         Dsa::private_key_from_pem_passphrase(key, b"mypass").unwrap();
     }
 
+    #[test]
+    fn test_to_password() {
+        let key = Dsa::generate(2048).unwrap();
+        let pem = key.private_key_to_pem_passphrase(Cipher::aes_128_cbc(), b"foobar").unwrap();
+        Dsa::private_key_from_pem_passphrase(&pem, b"foobar").unwrap();
+        assert!(Dsa::private_key_from_pem_passphrase(&pem, b"fizzbuzz").is_err());
+    }
+
     #[test]
     pub fn test_password_callback() {
         let mut password_queried = false;

openssl/src/macros.rs

@@ -113,5 +113,25 @@ macro_rules! private_key_to_pem {
                 Ok(bio.get_buf().to_owned())
             }
         }
+
+        /// Serializes the private key to PEM, encrypting it with the specified symmetric cipher and
+        /// passphrase.
+        pub fn private_key_to_pem_passphrase(&self,
+                                             cipher: ::symm::Cipher,
+                                             passphrase: &[u8])
+                                             -> Result<Vec<u8>, ::error::ErrorStack> {
+            unsafe {
+                let bio = try!(::bio::MemBio::new());
+                assert!(passphrase.len() <= ::libc::c_int::max_value() as usize);
+                try!(cvt($f(bio.as_ptr(),
+                            self.as_ptr(),
+                            cipher.as_ptr(),
+                            passphrase.as_ptr() as *const _ as *mut _,
+                            passphrase.len() as ::libc::c_int,
+                            None,
+                            ptr::null_mut())));
+                Ok(bio.get_buf().to_owned())
+            }
+        }
     }
 }

openssl/src/pkey.rs

@@ -48,7 +48,7 @@ impl PKeyRef {
         }
     }
 
-    private_key_to_pem!(ffi::PEM_write_bio_PrivateKey);
+    private_key_to_pem!(ffi::PEM_write_bio_PKCS8PrivateKey);
 
     /// Encodes the public key in the PEM format.
     pub fn public_key_to_pem(&self) -> Result<Vec<u8>, ErrorStack> {
@@ -185,6 +185,7 @@ impl PKey {
 
 #[cfg(test)]
 mod tests {
+    use symm::Cipher;
     use dh::Dh;
     use dsa::Dsa;
     use ec_key::EcKey;
@@ -193,6 +194,15 @@ mod tests {
 
     use super::*;
 
+    #[test]
+    fn test_to_password() {
+        let rsa = Rsa::generate(2048).unwrap();
+        let pkey = PKey::from_rsa(rsa).unwrap();
+        let pem = pkey.private_key_to_pem_passphrase(Cipher::aes_128_cbc(), b"foobar").unwrap();
+        PKey::private_key_from_pem_passphrase(&pem, b"foobar").unwrap();
+        assert!(PKey::private_key_from_pem_passphrase(&pem, b"fizzbuzz").is_err());
+    }
+
     #[test]
     fn test_private_key_from_pem() {
         let key = include_bytes!("../test/key.pem");

openssl/src/rsa.rs

@@ -404,16 +404,18 @@ mod compat {
 
 #[cfg(test)]
 mod test {
+    use symm::Cipher;
+
     use super::*;
 
     #[test]
-    pub fn test_password() {
+    fn test_from_password() {
         let key = include_bytes!("../test/rsa-encrypted.pem");
         Rsa::private_key_from_pem_passphrase(key, b"mypass").unwrap();
     }
 
     #[test]
-    pub fn test_password_callback() {
+    fn test_from_password_callback() {
         let mut password_queried = false;
         let key = include_bytes!("../test/rsa-encrypted.pem");
         Rsa::private_key_from_pem_callback(key, |password| {
@@ -427,7 +429,15 @@ mod test {
     }
 
     #[test]
-    pub fn test_public_encrypt_private_decrypt_with_padding() {
+    fn test_to_password() {
+        let key = Rsa::generate(2048).unwrap();
+        let pem = key.private_key_to_pem_passphrase(Cipher::aes_128_cbc(), b"foobar").unwrap();
+        Rsa::private_key_from_pem_passphrase(&pem, b"foobar").unwrap();
+        assert!(Rsa::private_key_from_pem_passphrase(&pem, b"fizzbuzz").is_err());
+    }
+
+    #[test]
+    fn test_public_encrypt_private_decrypt_with_padding() {
         let key = include_bytes!("../test/rsa.pem.pub");
         let public_key = Rsa::public_key_from_pem(key).unwrap();