Test windows random shims

Author: ChrisDenton

src/tools/miri/tests/pass/shims/windows-rand.rs

@@ -0,0 +1,41 @@
+//@only-target-windows: this directly tests windows only random functions
+use core::ffi::c_void;
+use core::mem::size_of_val;
+use core::ptr::null_mut;
+
+// Windows API definitions.
+typeNTSTATUS = i32;
+typeBOOLEAN = u8;
+constBCRYPT_USE_SYSTEM_PREFERRED_RNG:u32 = 0x00000002;
+constBCRYPT_RNG_ALG_HANDLE:*mutc_void = 0x81as*mutc_void;
+#[link(name = "bcrypt")]
+extern"system"{
+fnBCryptGenRandom(
+halgorithm:*mutc_void,
+pbbuffer:*mutu8,
+cbbuffer:u32,
+dwflags:u32,
+) -> NTSTATUS;
+}
+#[link(name = "advapi32")]
+extern"system"{
+#[link_name = "SystemFunction036"]
+fnRtlGenRandom(RandomBuffer:*mutu8,RandomBufferLength:u32) -> BOOLEAN;
+}
+
+fnmain(){
+letmut key = [0u8;24];
+let len:u32 = size_of_val(&key).try_into().unwrap();
+let ret = unsafe{
+BCryptGenRandom(null_mut(), key.as_mut_ptr(), len,BCRYPT_USE_SYSTEM_PREFERRED_RNG)
+};
+// NTSTATUS codes use the high bit to indicate an error
+assert!(ret >= 0);
+
+let ret = unsafe{BCryptGenRandom(BCRYPT_RNG_ALG_HANDLE, key.as_mut_ptr(), len,0)};
+assert!(ret >= 0);
+
+let ret = unsafe{RtlGenRandom(key.as_mut_ptr(), len)};
+// RtlGenRandom returns a BOOLEAN where 0 indicates an error
+assert_ne!(ret,0);
+}