Merge pull request #244 from andrew-d/andrew-save-pubkey

Add function to write RSA public key as PEM

openssl-sys/src/lib.rs

@@ -468,6 +468,7 @@ extern "C" {
                                     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_X509(bio: *mut BIO, x509: *mut X509) -> c_int;
     pub fn PEM_write_bio_X509_REQ(bio: *mut BIO, x509: *mut X509_REQ) -> c_int;
 

openssl/src/crypto/pkey.rs

@@ -182,6 +182,17 @@ impl PKey {
         writer.write_all(&buf).map_err(StreamError)
     }
 
+    /// Stores public key as a PEM
+    pub fn write_pub_pem<W: Write>(&self, writer: &mut W/*, password: Option<String>*/) -> Result<(), SslError> {
+        let mut mem_bio = try!(MemBio::new());
+        unsafe {
+            try_ssl!(ffi::PEM_write_bio_PUBKEY(mem_bio.get_handle(), self.evp))
+        }
+        let mut buf = vec![];
+        try!(mem_bio.read_to_end(&mut buf).map_err(StreamError));
+        writer.write_all(&buf).map_err(StreamError)
+    }
+
     /**
      * Returns the size of the public key modulus.
      */
@@ -500,4 +511,25 @@ mod tests {
         assert!(!k0.public_eq(&p1));
         assert!(!p0.public_eq(&k1));
     }
+
+    #[test]
+    fn test_pem() {
+        let key_path = Path::new("test/key.pem");
+        let mut file = File::open(&key_path)
+            .ok()
+            .expect("Failed to open `test/key.pem`");
+
+        let key = super::PKey::private_key_from_pem(&mut file).unwrap();
+
+        let mut priv_key = Vec::new();
+        let mut pub_key = Vec::new();
+
+        key.write_pem(&mut priv_key).unwrap();
+        key.write_pub_pem(&mut pub_key).unwrap();
+
+        // As a super-simple verification, just check that the buffers contain
+        // the `PRIVATE KEY` or `PUBLIC KEY` strings.
+        assert!(priv_key.windows(11).any(|s| s == b"PRIVATE KEY"));
+        assert!(pub_key.windows(10).any(|s| s == b"PUBLIC KEY"));
+    }
 }