1 files changed, 67 insertions, 0 deletions
diff --git a/library/std/src/sys/random/sgx.rs b/library/std/src/sys/random/sgx.rs
new file mode 100644
index 00000000000..c3647a8df22
--- /dev/null
+++ b/library/std/src/sys/random/sgx.rs
@@ -0,0 +1,67 @@
+use crate::arch::x86_64::{_rdrand16_step, _rdrand32_step, _rdrand64_step};
+
+const RETRIES: u32 = 10;
+
+fn fail() -> ! {
+    panic!("failed to generate random data");
+}
+
+fn rdrand64() -> u64 {
+    unsafe {
+        let mut ret: u64 = 0;
+        for _ in 0..RETRIES {
+            if _rdrand64_step(&mut ret) == 1 {
+                return ret;
+            }
+        }
+
+        fail();
+    }
+}
+
+fn rdrand32() -> u32 {
+    unsafe {
+        let mut ret: u32 = 0;
+        for _ in 0..RETRIES {
+            if _rdrand32_step(&mut ret) == 1 {
+                return ret;
+            }
+        }
+
+        fail();
+    }
+}
+
+fn rdrand16() -> u16 {
+    unsafe {
+        let mut ret: u16 = 0;
+        for _ in 0..RETRIES {
+            if _rdrand16_step(&mut ret) == 1 {
+                return ret;
+            }
+        }
+
+        fail();
+    }
+}
+
+pub fn fill_bytes(bytes: &mut [u8]) {
+    let mut chunks = bytes.array_chunks_mut();
+    for chunk in &mut chunks {
+        *chunk = rdrand64().to_ne_bytes();
+    }
+
+    let mut chunks = chunks.into_remainder().array_chunks_mut();
+    for chunk in &mut chunks {
+        *chunk = rdrand32().to_ne_bytes();
+    }
+
+    let mut chunks = chunks.into_remainder().array_chunks_mut();
+    for chunk in &mut chunks {
+        *chunk = rdrand16().to_ne_bytes();
+    }
+
+    if let [byte] = chunks.into_remainder() {
+        *byte = rdrand16() as u8;
+    }
+}