4 files changed, 185 insertions, 0 deletions
diff --git a/third_party/rust/getrandom/tests/common/mod.rs b/third_party/rust/getrandom/tests/common/mod.rs
new file mode 100644
index 0000000000..666f7f5702
--- /dev/null
+++ b/third_party/rust/getrandom/tests/common/mod.rs
@@ -0,0 +1,100 @@
+use super::getrandom_impl;
+
+#[cfg(all(target_arch = "wasm32", target_os = "unknown"))]
+use wasm_bindgen_test::wasm_bindgen_test as test;
+
+#[cfg(feature = "test-in-browser")]
+wasm_bindgen_test::wasm_bindgen_test_configure!(run_in_browser);
+
+#[test]
+fn test_zero() {
+    // Test that APIs are happy with zero-length requests
+    getrandom_impl(&mut [0u8; 0]).unwrap();
+}
+
+// Return the number of bits in which s1 and s2 differ
+#[cfg(not(feature = "custom"))]
+fn num_diff_bits(s1: &[u8], s2: &[u8]) -> usize {
+    assert_eq!(s1.len(), s2.len());
+    s1.iter()
+        .zip(s2.iter())
+        .map(|(a, b)| (a ^ b).count_ones() as usize)
+        .sum()
+}
+
+// Tests the quality of calling getrandom on two large buffers
+#[test]
+#[cfg(not(feature = "custom"))]
+fn test_diff() {
+    let mut v1 = [0u8; 1000];
+    getrandom_impl(&mut v1).unwrap();
+
+    let mut v2 = [0u8; 1000];
+    getrandom_impl(&mut v2).unwrap();
+
+    // Between 3.5 and 4.5 bits per byte should differ. Probability of failure:
+    // ~ 2^(-94) = 2 * CDF[BinomialDistribution[8000, 0.5], 3500]
+    let d = num_diff_bits(&v1, &v2);
+    assert!(d > 3500);
+    assert!(d < 4500);
+}
+
+// Tests the quality of calling getrandom repeatedly on small buffers
+#[test]
+#[cfg(not(feature = "custom"))]
+fn test_small() {
+    // For each buffer size, get at least 256 bytes and check that between
+    // 3 and 5 bits per byte differ. Probability of failure:
+    // ~ 2^(-91) = 64 * 2 * CDF[BinomialDistribution[8*256, 0.5], 3*256]
+    for size in 1..=64 {
+        let mut num_bytes = 0;
+        let mut diff_bits = 0;
+        while num_bytes < 256 {
+            let mut s1 = vec![0u8; size];
+            getrandom_impl(&mut s1).unwrap();
+            let mut s2 = vec![0u8; size];
+            getrandom_impl(&mut s2).unwrap();
+
+            num_bytes += size;
+            diff_bits += num_diff_bits(&s1, &s2);
+        }
+        assert!(diff_bits > 3 * num_bytes);
+        assert!(diff_bits < 5 * num_bytes);
+    }
+}
+
+#[test]
+fn test_huge() {
+    let mut huge = [0u8; 100_000];
+    getrandom_impl(&mut huge).unwrap();
+}
+
+// On WASM, the thread API always fails/panics
+#[cfg(not(target_arch = "wasm32"))]
+#[test]
+fn test_multithreading() {
+    extern crate std;
+    use std::{sync::mpsc::channel, thread, vec};
+
+    let mut txs = vec![];
+    for _ in 0..20 {
+        let (tx, rx) = channel();
+        txs.push(tx);
+
+        thread::spawn(move || {
+            // wait until all the tasks are ready to go.
+            rx.recv().unwrap();
+            let mut v = [0u8; 1000];
+
+            for _ in 0..100 {
+                getrandom_impl(&mut v).unwrap();
+                thread::yield_now();
+            }
+        });
+    }
+
+    // start all the tasks
+    for tx in txs.iter() {
+        tx.send(()).unwrap();
+    }
+}
diff --git a/third_party/rust/getrandom/tests/custom.rs b/third_party/rust/getrandom/tests/custom.rs
new file mode 100644
index 0000000000..b085094be8
--- /dev/null
+++ b/third_party/rust/getrandom/tests/custom.rs
@@ -0,0 +1,54 @@
+// Test that a custom handler works on wasm32-unknown-unknown
+#![cfg(all(
+    target_arch = "wasm32",
+    target_os = "unknown",
+    feature = "custom",
+    not(feature = "js")
+))]
+
+use wasm_bindgen_test::wasm_bindgen_test as test;
+
+use core::num::NonZeroU32;
+use getrandom::{getrandom, register_custom_getrandom, Error};
+
+fn len7_err() -> Error {
+    NonZeroU32::new(Error::INTERNAL_START + 7).unwrap().into()
+}
+
+fn super_insecure_rng(buf: &mut [u8]) -> Result<(), Error> {
+    // `getrandom` guarantees it will not call any implementation if the output
+    // buffer is empty.
+    assert!(!buf.is_empty());
+    // Length 7 buffers return a custom error
+    if buf.len() == 7 {
+        return Err(len7_err());
+    }
+    // Otherwise, fill bytes based on input length
+    let mut start = buf.len() as u8;
+    for b in buf {
+        *b = start;
+        start = start.wrapping_mul(3);
+    }
+    Ok(())
+}
+
+register_custom_getrandom!(super_insecure_rng);
+
+use getrandom::getrandom as getrandom_impl;
+mod common;
+
+#[test]
+fn custom_rng_output() {
+    let mut buf = [0u8; 4];
+    assert_eq!(getrandom(&mut buf), Ok(()));
+    assert_eq!(buf, [4, 12, 36, 108]);
+
+    let mut buf = [0u8; 3];
+    assert_eq!(getrandom(&mut buf), Ok(()));
+    assert_eq!(buf, [3, 9, 27]);
+}
+
+#[test]
+fn rng_err_output() {
+    assert_eq!(getrandom(&mut [0; 7]), Err(len7_err()));
+}
diff --git a/third_party/rust/getrandom/tests/normal.rs b/third_party/rust/getrandom/tests/normal.rs
new file mode 100644
index 0000000000..5fff13b38e
--- /dev/null
+++ b/third_party/rust/getrandom/tests/normal.rs
@@ -0,0 +1,11 @@
+// Don't test on custom wasm32-unknown-unknown
+#![cfg(not(all(
+    target_arch = "wasm32",
+    target_os = "unknown",
+    feature = "custom",
+    not(feature = "js")
+)))]
+
+// Use the normal getrandom implementation on this architecture.
+use getrandom::getrandom as getrandom_impl;
+mod common;
diff --git a/third_party/rust/getrandom/tests/rdrand.rs b/third_party/rust/getrandom/tests/rdrand.rs
new file mode 100644
index 0000000000..25678683f3
--- /dev/null
+++ b/third_party/rust/getrandom/tests/rdrand.rs
@@ -0,0 +1,20 @@
+// We only test the RDRAND-based RNG source on supported architectures.
+#![cfg(any(target_arch = "x86_64", target_arch = "x86"))]
+
+// rdrand.rs expects to be part of the getrandom main crate, so we need these
+// additional imports to get rdrand.rs to compile.
+use getrandom::Error;
+#[macro_use]
+extern crate cfg_if;
+#[path = "../src/rdrand.rs"]
+mod rdrand;
+#[path = "../src/util.rs"]
+mod util;
+
+// The rdrand implementation has the signature of getrandom_uninit(), but our
+// tests expect getrandom_impl() to have the signature of getrandom().
+fn getrandom_impl(dest: &mut [u8]) -> Result<(), Error> {
+    rdrand::getrandom_inner(unsafe { util::slice_as_uninit_mut(dest) })?;
+    Ok(())
+}
+mod common;