passing encryption key from builder to Lmdb lib, with proper memory management

Cargo.toml

@@ -2,7 +2,7 @@
 name = "lmdb-lofire"
 # NB: When modifying, also modify html_root_url in lib.rs
 version = "0.14.0"
-authors = ["NikoPLP <info@parlepeuple.fr>"]
+authors = ["Dan Burkert <dan@danburkert.com>", "Victor Porof <vporof@mozilla.com>","NikoPLP <info@parlepeuple.fr>"]
 license = "Apache-2.0"
 description = "Idiomatic and safe LMDB wrapper."
 documentation = "https://docs.rs/lmdb-lofire"

lmdb-sys/build.rs

@@ -65,6 +65,7 @@ fn main() {
         builder
             .define("MDB_IDL_LOGN", Some(MDB_IDL_LOGN.to_string().as_str()))
             .file(lmdb.join("mdb.c"))
+            .file(lmdb.join("chacha8.c"))
             .file(lmdb.join("midl.c"))
             // https://github.com/mozilla/lmdb/blob/b7df2cac50fb41e8bd16aab4cc5fd167be9e032a/libraries/liblmdb/Makefile#L23
             .flag_if_supported("-Wno-unused-parameter")

lmdb-sys/lmdb

@@ -1 +1 @@
-Subproject commit a9e0d9dfcaa30a885b250fc71bbc31a2a597842b
+Subproject commit 6156b10356e3b2840abed2afd59f7a2ea2581f42

lmdb-sys/src/bindings.rs

@@ -591,6 +591,9 @@ extern "C" {
     #[doc = " </ul>"]
     pub fn mdb_env_set_mapsize(env: *mut MDB_env, size: usize) -> ::libc::c_int;
 }
+extern "C" {
+    pub fn mdb_env_init_crypto(env: *mut MDB_env, key: *mut ::libc::c_void) -> ::libc::c_int;
+}
 extern "C" {
     #[doc = " @brief Set the maximum number of threads/reader slots for the environment."]
     #[doc = ""]

lmdb-sys/tests/simple.rs

@@ -59,8 +59,8 @@ fn test_simple(env_path: &str) {
         mv_data: ptr::null_mut(),
     };
     let mut txn: *mut MDB_txn = ptr::null_mut();
-    let sval = str!("fdedeoo") as *mut c_void;
-    let dval = str!("bdedear") as *mut c_void;
+    //let sval = str!("fdedeoo") as *mut c_void;
+    //let dval = str!("bdedear") as *mut c_void;
 
     let mut buffer: [u8; 7] = [0; 7];
     buffer[0] = 65;
@@ -77,7 +77,7 @@ fn test_simple(env_path: &str) {
         E!(mdb_env_open(env, str!(env_path), 0, 0664));
 
         E!(mdb_txn_begin(env, ptr::null_mut(), 0, &mut txn));
-        E!(mdb_dbi_open(txn, str!("test"), MDB_CREATE, &mut dbi));
+        E!(mdb_dbi_open(txn, str!("testdb"), MDB_CREATE, &mut dbi));
         E!(mdb_txn_commit(txn));
 
         key.mv_size = 7;

src/environment.rs

@@ -1,9 +1,11 @@
 use libc::{c_uint, size_t};
+use std::alloc::{alloc, dealloc, Layout};
 use std::ffi::CStr;
 use std::ffi::CString;
 #[cfg(windows)]
 use std::ffi::OsStr;
 use std::os::raw::c_char;
+
 #[cfg(unix)]
 use std::os::unix::ffi::OsStrExt;
 use std::path::Path;
@@ -20,6 +22,8 @@ use error::{lmdb_result, Error, Result};
 use flags::{DatabaseFlags, EnvironmentFlags};
 use transaction::{RoTransaction, RwTransaction, Transaction};
 
+use libc::c_void;
+
 #[cfg(windows)]
 /// Adding a 'missing' trait from windows OsStrExt
 trait OsStrExtLmdb {
@@ -32,12 +36,15 @@ impl OsStrExtLmdb for OsStr {
     }
 }
 
+static ZEROS: [u8; 32] = [0; 32];
+
 /// An LMDB environment.
 ///
 /// An environment supports multiple databases, all residing in the same shared-memory map.
 pub struct Environment {
     env: *mut ffi::MDB_env,
     dbi_open_mutex: Mutex<()>,
+    enc_key_ptr: *mut u8,
 }
 
 impl Environment {
@@ -49,6 +56,7 @@ impl Environment {
             max_readers: None,
             max_dbs: None,
             map_size: None,
+            encryption_key: None,
         }
     }
 
@@ -363,7 +371,16 @@ impl fmt::Debug for Environment {
 
 impl Drop for Environment {
     fn drop(&mut self) {
-        unsafe { ffi::mdb_env_close(self.env) }
+        unsafe {
+            ffi::mdb_env_close(self.env);
+            if !self.enc_key_ptr.is_null() {
+                // zeros the heap memory that was used for the key
+                std::ptr::copy(ZEROS.as_ptr(), self.enc_key_ptr, 16);
+                // and dealloc it
+                let layout = Layout::new::<[u8; 32]>();
+                dealloc(self.enc_key_ptr, layout);
+            }
+        }
     }
 }
 
@@ -378,6 +395,7 @@ pub struct EnvironmentBuilder {
     max_readers: Option<c_uint>,
     max_dbs: Option<c_uint>,
     map_size: Option<size_t>,
+    encryption_key: Option<[u8; 32]>,
 }
 
 impl EnvironmentBuilder {
@@ -399,8 +417,18 @@ impl EnvironmentBuilder {
     /// paths are not supported either.
     pub fn open_with_permissions(&self, path: &Path, mode: ffi::mdb_mode_t) -> Result<Environment> {
         let mut env: *mut ffi::MDB_env = ptr::null_mut();
+        let mut enc_key_ptr: *mut u8 = ptr::null_mut();
         unsafe {
             lmdb_try!(ffi::mdb_env_create(&mut env));
+            if let Some(encryption_key) = self.encryption_key {
+                let layout = Layout::new::<[u8; 32]>();
+                enc_key_ptr = alloc(layout);
+                std::ptr::copy(encryption_key.as_ptr(), enc_key_ptr, 32);
+                lmdb_try_with_cleanup!(ffi::mdb_env_init_crypto(env, enc_key_ptr as *mut c_void), || {
+                    ffi::mdb_env_close(env);
+                    dealloc(enc_key_ptr, layout);
+                })
+            }
             if let Some(max_readers) = self.max_readers {
                 lmdb_try_with_cleanup!(ffi::mdb_env_set_maxreaders(env, max_readers), ffi::mdb_env_close(env))
             }
@@ -421,6 +449,7 @@ impl EnvironmentBuilder {
         }
         Ok(Environment {
             env,
+            enc_key_ptr,
             dbi_open_mutex: Mutex::new(()),
         })
     }
@@ -471,6 +500,12 @@ impl EnvironmentBuilder {
         self.map_size = Some(map_size);
         self
     }
+
+    /// Sets the encryption key to use for the environment.
+    pub fn set_enc_key(&mut self, key: [u8; 32]) -> &mut EnvironmentBuilder {
+        self.encryption_key = Some(key);
+        self
+    }
 }
 
 #[cfg(test)]