From ef95223d2679d68b36df77393bd334d4da02077f Mon Sep 17 00:00:00 2001
From: Benjamin Fry <benjaminfry@me.com>
Date: Wed, 17 Feb 2016 23:18:42 -0800
Subject: [PATCH] adding functionality to directly get and set RSA key material

---
 openssl-sys/src/lib.rs     |  1 +
 openssl/src/bn/mod.rs      |  5 +++++
 openssl/src/crypto/pkey.rs | 24 ++++++++++++++++++++++++
 openssl/src/crypto/rsa.rs  | 37 ++++++++++++++++++++++++++++++++++++-
 4 files changed, 66 insertions(+), 1 deletion(-)

diff --git a/openssl-sys/src/lib.rs b/openssl-sys/src/lib.rs
index ff221935..d03fed31 100644
--- a/openssl-sys/src/lib.rs
+++ b/openssl-sys/src/lib.rs
@@ -588,6 +588,7 @@ extern "C" {
 
     pub fn RAND_bytes(buf: *mut u8, num: c_int) -> c_int;
 
+    pub fn RSA_new() -> *mut RSA;
     pub fn RSA_free(rsa: *mut RSA);
     pub fn RSA_generate_key(modsz: c_int, e: c_ulong, cb: *const c_void, cbarg: *const c_void) -> *mut RSA;
     pub fn RSA_generate_key_ex(rsa: *mut RSA, bits: c_int, e: *mut BIGNUM, cb: *const c_void) -> c_int;
diff --git a/openssl/src/bn/mod.rs b/openssl/src/bn/mod.rs
index 00a0a0ca..70a10154 100644
--- a/openssl/src/bn/mod.rs
+++ b/openssl/src/bn/mod.rs
@@ -473,6 +473,11 @@ impl BigNum {
         n
     }
 
+    pub unsafe fn into_raw(self) -> *mut ffi::BIGNUM {
+        let mut me = self;
+        ptr::replace(&mut me.0, ptr::null_mut())
+    }
+
     pub fn to_vec(&self) -> Vec<u8> {
         let size = self.num_bytes() as usize;
         let mut v = Vec::with_capacity(size);
diff --git a/openssl/src/crypto/pkey.rs b/openssl/src/crypto/pkey.rs
index e556730d..dc613bc7 100644
--- a/openssl/src/crypto/pkey.rs
+++ b/openssl/src/crypto/pkey.rs
@@ -205,6 +205,30 @@ impl PKey {
         }
     }
 
+    /// pass ownership of the RSA key to this
+    pub fn set_rsa(&mut self, rsa: RSA) {
+        unsafe {
+            // TODO: should we do something like panic if null? this will fail silently right now
+            let rsa_ptr = rsa.as_ptr();
+            if !rsa_ptr.is_null() {
+                if ffi::EVP_PKEY_set1_RSA(self.evp, rsa_ptr) == 1 {
+                    if rsa.has_e() && rsa.has_n() {
+                        self.parts = Parts::Public;
+                    }
+                }
+            }
+        }
+    }
+
+    /// get a reference to the interal RSA key for direct access to the key components
+    pub fn get_rsa(&self) -> RSA {
+        unsafe {
+            let evp_pkey: *mut ffi::EVP_PKEY = self.evp;
+            // this is safe as the ffi increments a reference counter to the internal key
+            RSA(ffi::EVP_PKEY_get1_RSA(evp_pkey))
+        }
+    }
+
     /**
      * Returns a DER serialized form of the public key, suitable for load_pub().
      */
diff --git a/openssl/src/crypto/rsa.rs b/openssl/src/crypto/rsa.rs
index ee0d9ec4..034f8828 100644
--- a/openssl/src/crypto/rsa.rs
+++ b/openssl/src/crypto/rsa.rs
@@ -7,7 +7,7 @@ use std::io::{self, Read};
 use bn::BigNum;
 use bio::MemBio;
 
-pub struct RSA(*mut ffi::RSA);
+pub struct RSA(pub *mut ffi::RSA);
 
 impl Drop for RSA {
     fn drop(&mut self) {
@@ -18,6 +18,15 @@ impl Drop for RSA {
 }
 
 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.
+    pub fn new() -> Result<RSA, SslError> {
+        unsafe {
+            let rsa = try_ssl_null!(ffi::RSA_new());
+            Ok(RSA(rsa))
+        }
+    }
+
     /// Reads an RSA private key from PEM formatted data.
     pub fn private_key_from_pem<R>(reader: &mut R) -> Result<RSA, SslError>
     where R: Read
@@ -61,6 +70,19 @@ impl RSA {
         }
     }
 
+    /// set the key modulus
+    pub fn set_n(&mut self, n: BigNum) {
+        unsafe {
+            (*self.0).n = n.into_raw();
+        }
+    }
+
+    pub fn has_n(&self) -> bool {
+        unsafe {
+            !(*self.0).n.is_null()
+        }
+    }
+
     pub fn d(&self) -> Result<BigNum, SslError> {
         unsafe {
             BigNum::new_from_ffi((*self.0).d)
@@ -73,6 +95,19 @@ impl RSA {
         }
     }
 
+    /// set the exponent
+    pub fn set_e(&mut self, e: BigNum) {
+        unsafe {
+            (*self.0).e = e.into_raw();
+        }
+    }
+
+    pub fn has_e(&self) -> bool {
+        unsafe {
+            !(*self.0).e.is_null()
+        }
+    }
+
     pub fn p(&self) -> Result<BigNum, SslError> {
         unsafe {
             BigNum::new_from_ffi((*self.0).p)