Merge #910

910: Use getrandom instead of rand r=MarkMcCaskey a=newpavlov Closes #909 Note: I am reusing `__WASI_EIO` as an error code to denote a potential OS RNG failure. Co-authored-by: newpavlov <[email protected]> Co-authored-by: Artyom Pavlov <[email protected]>
wasmerio · Oct 28, 2019 · d46e5d4 · d46e5d4
2 parents 8653216 + 5647559
commit d46e5d4
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Showing 5 changed files with 16 additions and 16 deletions.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/lib/emscripten/Cargo.toml b/lib/emscripten/Cargo.toml
@@ -15,7 +15,7 @@ time = "0.1"
 wasmer-runtime-core = { path = "../runtime-core", version = "0.9.0" }
 
 [target.'cfg(windows)'.dependencies]
-rand = "0.7"
+getrandom = "0.1"
 
 [features]
 debug = ["wasmer-runtime-core/debug"]
diff --git a/lib/emscripten/src/syscalls/windows.rs b/lib/emscripten/src/syscalls/windows.rs
@@ -2,7 +2,6 @@ use crate::utils::{copy_cstr_into_wasm, get_cstr_path};
 use crate::varargs::VarArgs;
 use libc::mkdir;
 use libc::open;
-use rand::Rng;
 use std::env;
 use std::ffi::CString;
 use std::fs::File;
@@ -39,7 +38,8 @@ pub fn ___syscall5(ctx: &mut Ctx, which: c_int, mut varargs: VarArgs) -> c_int {
             let ptr = tmp_dir_c_str.as_ptr() as *const i8;
             let mut urandom_file = File::create(tmp_dir).unwrap();
             // create some random bytes and put them into the file
-            let random_bytes = rand::thread_rng().gen::<[u8; 32]>();
+            let mut random_bytes = [0u8; 32];
+            getrandom::getrandom(&mut random_bytes).unwrap();
             let _ = urandom_file.write_all(&random_bytes).unwrap();
             // put the file path string into wasm memory
             let urandom_file_offset = unsafe { copy_cstr_into_wasm(ctx, ptr) };

diff --git a/lib/wasi/Cargo.toml b/lib/wasi/Cargo.toml
@@ -13,7 +13,7 @@ byteorder = "1.3"
 generational-arena = { version = "0.2", features = ["serde"] }
 libc = "0.2.60"
 log = "0.4"
-rand = "0.7"
+getrandom = "0.1"
 time = "0.1"
 typetag = "0.1"
 serde = { version = "1", features = ["derive"] }

diff --git a/lib/wasi/src/syscalls/mod.rs b/lib/wasi/src/syscalls/mod.rs
@@ -15,7 +15,6 @@ use crate::{
     },
     ExitCode,
 };
-use rand::{thread_rng, Rng};
 use std::borrow::Borrow;
 use std::cell::Cell;
 use std::convert::{Infallible, TryInto};
@@ -2453,17 +2452,18 @@ pub fn proc_raise(ctx: &mut Ctx, sig: __wasi_signal_t) -> __wasi_errno_t {
 ///     The number of bytes that will be written
 pub fn random_get(ctx: &mut Ctx, buf: WasmPtr<u8, Array>, buf_len: u32) -> __wasi_errno_t {
     debug!("wasi::random_get buf_len: {}", buf_len);
-    let mut rng = thread_rng();
     let memory = ctx.memory(0);
 
     let buf = wasi_try!(buf.deref(memory, 0, buf_len));
 
-    unsafe {
+    let res = unsafe {
         let u8_buffer = &mut *(buf as *const [_] as *mut [_] as *mut [u8]);
-        thread_rng().fill(u8_buffer);
+        getrandom::getrandom(u8_buffer)
+    };
+    match res {
+        Ok(()) => __WASI_ESUCCESS,
+        Err(_) => __WASI_EIO,
     }
-
-    __WASI_ESUCCESS
 }
 
 /// ### `sched_yield()`