diff --git a/libs/binder/ndk/ibinder.cpp b/libs/binder/ndk/ibinder.cpp
index d287290..6995e77 100644
--- a/libs/binder/ndk/ibinder.cpp
+++ b/libs/binder/ndk/ibinder.cpp
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include <android/binder_context.h>
 #include <android/binder_ibinder.h>
 #include <android/binder_ibinder_platform.h>
 #include "ibinder_internal.h"
diff --git a/libs/binder/ndk/include_platform/android/binder_context.h b/libs/binder/ndk/include_platform/android/binder_context.h
new file mode 100644
index 0000000..a99d555
--- /dev/null
+++ b/libs/binder/ndk/include_platform/android/binder_context.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <android/binder_ibinder.h>
+
+__BEGIN_DECLS
+
+/**
+ * Makes calls to AIBinder_getCallingSid work if the kernel supports it. This
+ * must be called on a local binder server before it is sent out to any othe
+ * process. If this is a remote binder, it will abort. If the kernel doesn't
+ * support this feature, you'll always get null from AIBinder_getCallingSid.
+ *
+ * \param binder local server binder to request security contexts on
+ */
+__attribute__((weak)) void AIBinder_setRequestingSid(AIBinder* binder, bool requestingSid)
+        __INTRODUCED_IN(31);
+
+/**
+ * Returns the selinux context of the callee.
+ *
+ * In order for this to work, the following conditions must be met:
+ * - The kernel must be new enough to support this feature.
+ * - The server must have called AIBinder_setRequestingSid.
+ * - The callee must be a remote process.
+ *
+ * \return security context or null if unavailable. The lifetime of this context
+ * is the lifetime of the transaction.
+ */
+__attribute__((weak, warn_unused_result)) const char* AIBinder_getCallingSid() __INTRODUCED_IN(31);
+
+__END_DECLS
diff --git a/libs/binder/ndk/include_platform/android/binder_ibinder_platform.h b/libs/binder/ndk/include_platform/android/binder_ibinder_platform.h
index 5811760..2af65cf 100644
--- a/libs/binder/ndk/include_platform/android/binder_ibinder_platform.h
+++ b/libs/binder/ndk/include_platform/android/binder_ibinder_platform.h
@@ -16,41 +16,14 @@
 
 #pragma once
 
+// binder_context.h used to be part of this header and is included for backwards
+// compatibility.
+#include <android/binder_context.h>
+
+#if !defined(__ANDROID_APEX__) && !defined(__ANDROID_VNDK__)
+
 #include <android/binder_ibinder.h>
-
-#if !defined(__ANDROID_APEX__) && !defined(__ANDROID_VNDK__)
 #include <binder/IBinder.h>
-#endif
-
-__BEGIN_DECLS
-
-/**
- * Makes calls to AIBinder_getCallingSid work if the kernel supports it. This
- * must be called on a local binder server before it is sent out to any othe
- * process. If this is a remote binder, it will abort. If the kernel doesn't
- * support this feature, you'll always get null from AIBinder_getCallingSid.
- *
- * \param binder local server binder to request security contexts on
- */
-__attribute__((weak)) void AIBinder_setRequestingSid(AIBinder* binder, bool requestingSid)
-        __INTRODUCED_IN(31);
-
-/**
- * Returns the selinux context of the callee.
- *
- * In order for this to work, the following conditions must be met:
- * - The kernel must be new enough to support this feature.
- * - The server must have called AIBinder_setRequestingSid.
- * - The callee must be a remote process.
- *
- * \return security context or null if unavailable. The lifetime of this context
- * is the lifetime of the transaction.
- */
-__attribute__((weak, warn_unused_result)) const char* AIBinder_getCallingSid() __INTRODUCED_IN(31);
-
-__END_DECLS
-
-#if !defined(__ANDROID_APEX__) && !defined(__ANDROID_VNDK__)
 
 /**
  * Get libbinder version of binder from AIBinder.
diff --git a/libs/binder/ndk/tests/libbinder_ndk_unit_test.cpp b/libs/binder/ndk/tests/libbinder_ndk_unit_test.cpp
index 6281014..44d8ebf 100644
--- a/libs/binder/ndk/tests/libbinder_ndk_unit_test.cpp
+++ b/libs/binder/ndk/tests/libbinder_ndk_unit_test.cpp
@@ -18,6 +18,7 @@
 #include <aidl/BnBinderNdkUnitTest.h>
 #include <aidl/BnEmpty.h>
 #include <android-base/logging.h>
+#include <android/binder_context.h>
 #include <android/binder_ibinder_jni.h>
 #include <android/binder_ibinder_platform.h>
 #include <android/binder_manager.h>
diff --git a/libs/binder/rust/src/binder.rs b/libs/binder/rust/src/binder.rs
index 6bf9cd5..ceb6ade 100644
--- a/libs/binder/rust/src/binder.rs
+++ b/libs/binder/rust/src/binder.rs
@@ -98,6 +98,9 @@
     /// Send a ping transaction to this object
     fn ping_binder(&mut self) -> Result<()>;
 
+    /// Indicate that the service intends to receive caller security contexts.
+    fn set_requesting_sid(&mut self, enable: bool);
+
     /// Dump this object to the given file handle
     fn dump<F: AsRawFd>(&mut self, fp: &F, args: &[&str]) -> Result<()>;
 
diff --git a/libs/binder/rust/src/proxy.rs b/libs/binder/rust/src/proxy.rs
index 5602c96..82212d8 100644
--- a/libs/binder/rust/src/proxy.rs
+++ b/libs/binder/rust/src/proxy.rs
@@ -249,6 +249,12 @@
         status_result(status)
     }
 
+    fn set_requesting_sid(&mut self, enable: bool) {
+        unsafe {
+            sys::AIBinder_setRequestingSid(self.as_native_mut(), enable)
+        };
+    }
+
     fn dump<F: AsRawFd>(&mut self, fp: &F, args: &[&str]) -> Result<()> {
         let args: Vec<_> = args.iter().map(|a| CString::new(*a).unwrap()).collect();
         let mut arg_ptrs: Vec<_> = args.iter().map(|a| a.as_ptr()).collect();
diff --git a/libs/binder/rust/src/state.rs b/libs/binder/rust/src/state.rs
index 992f074..0e05f10 100644
--- a/libs/binder/rust/src/state.rs
+++ b/libs/binder/rust/src/state.rs
@@ -98,4 +98,36 @@
             sys::AIBinder_getCallingPid()
         }
     }
+
+    /// This function makes the client's security context available to the
+    /// service calling this function. This can be used for access control.
+    /// It does not suffer from the TOCTOU issues of get_calling_pid.
+    ///
+    /// Implementations of `check_permission` should use the given CStr
+    /// argument as context for selinux permission checks. If `None` is
+    /// given, the implementation should fall back to using the PID
+    /// instead.
+    ///
+    /// Note: `None` may be passed to the callback if the caller did not
+    /// `set_requesting_sid` on the serviced binder, or if the underlying
+    /// kernel is too old to support this feature.
+    pub fn with_calling_sid<T, F>(check_permission: F) -> T
+    where
+        for<'a> F: FnOnce(Option<&'a std::ffi::CStr>) -> T {
+        // Safety: AIBinder_getCallingSid returns a c-string pointer
+        // that is valid for a transaction. Also, the string returned
+        // is thread local. By restricting the lifetime of the CStr
+        // reference to the scope of the callback, we prevent it being
+        // used beyond the guaranteed lifetime.
+        check_permission(unsafe {
+            let sid = sys::AIBinder_getCallingSid();
+            // AIBinder_getCallingSid() returns a '\0' terminated string
+            // or NULL.
+            if sid.is_null() {
+                None
+            } else {
+                Some(std::ffi::CStr::from_ptr(sid))
+            }
+        })
+    }
 }
diff --git a/libs/binder/rust/sys/BinderBindings.h b/libs/binder/rust/sys/BinderBindings.h
index c7a06d9..303f4a5 100644
--- a/libs/binder/rust/sys/BinderBindings.h
+++ b/libs/binder/rust/sys/BinderBindings.h
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include <android/binder_context.h>
 #include <android/binder_ibinder.h>
 #include <android/binder_manager.h>
 #include <android/binder_parcel.h>
diff --git a/libs/binder/rust/tests/Android.bp b/libs/binder/rust/tests/Android.bp
index 622604f..3db40ba 100644
--- a/libs/binder/rust/tests/Android.bp
+++ b/libs/binder/rust/tests/Android.bp
@@ -3,6 +3,10 @@
     srcs: ["integration.rs"],
     rustlibs: [
         "libbinder_rs",
+        "libselinux_bindgen",
+    ],
+    shared_libs: [
+        "libselinux",
     ],
     // For the binaries to be pushed properly as specified in AndroidTest.xml,
     // this cannot be the same as the module name.
diff --git a/libs/binder/rust/tests/integration.rs b/libs/binder/rust/tests/integration.rs
index fe59416..953d328 100644
--- a/libs/binder/rust/tests/integration.rs
+++ b/libs/binder/rust/tests/integration.rs
@@ -18,7 +18,8 @@
 
 use binder::declare_binder_interface;
 use binder::parcel::Parcel;
-use binder::{Binder, IBinder, Interface, SpIBinder, TransactionCode};
+use binder::{Binder, IBinder, Interface, SpIBinder, StatusCode, ThreadState, TransactionCode};
+use std::convert::{TryFrom, TryInto};
 
 /// Name of service runner.
 ///
@@ -49,6 +50,7 @@
         let mut service = Binder::new(BnTest(Box::new(TestService {
             s: service_name.clone(),
         })));
+        service.set_requesting_sid(true);
         if let Some(extension_name) = extension_name {
             let extension = BnTest::new_binder(TestService { s: extension_name });
             service
@@ -79,18 +81,47 @@
     s: String,
 }
 
+#[repr(u32)]
+enum TestTransactionCode {
+    Test = SpIBinder::FIRST_CALL_TRANSACTION,
+    GetSelinuxContext,
+}
+
+impl TryFrom<u32> for TestTransactionCode {
+    type Error = StatusCode;
+
+    fn try_from(c: u32) -> Result<Self, Self::Error> {
+        match c {
+            _ if c == TestTransactionCode::Test as u32 => Ok(TestTransactionCode::Test),
+            _ if c == TestTransactionCode::GetSelinuxContext as u32 => {
+                Ok(TestTransactionCode::GetSelinuxContext)
+            }
+            _ => Err(StatusCode::UNKNOWN_TRANSACTION),
+        }
+    }
+}
+
 impl Interface for TestService {}
 
 impl ITest for TestService {
     fn test(&self) -> binder::Result<String> {
         Ok(self.s.clone())
     }
+
+    fn get_selinux_context(&self) -> binder::Result<String> {
+        let sid =
+            ThreadState::with_calling_sid(|sid| sid.map(|s| s.to_string_lossy().into_owned()));
+        sid.ok_or(StatusCode::UNEXPECTED_NULL)
+    }
 }
 
 /// Trivial testing binder interface
 pub trait ITest: Interface {
     /// Returns a test string
     fn test(&self) -> binder::Result<String>;
+
+    /// Returns the caller's SELinux context
+    fn get_selinux_context(&self) -> binder::Result<String>;
 }
 
 declare_binder_interface! {
@@ -104,19 +135,30 @@
 
 fn on_transact(
     service: &dyn ITest,
-    _code: TransactionCode,
+    code: TransactionCode,
     _data: &Parcel,
     reply: &mut Parcel,
 ) -> binder::Result<()> {
-    reply.write(&service.test()?)?;
-    Ok(())
+    match code.try_into()? {
+        TestTransactionCode::Test => reply.write(&service.test()?),
+        TestTransactionCode::GetSelinuxContext => reply.write(&service.get_selinux_context()?),
+    }
 }
 
 impl ITest for BpTest {
     fn test(&self) -> binder::Result<String> {
-        let reply = self
-            .binder
-            .transact(SpIBinder::FIRST_CALL_TRANSACTION, 0, |_| Ok(()))?;
+        let reply =
+            self.binder
+                .transact(TestTransactionCode::Test as TransactionCode, 0, |_| Ok(()))?;
+        reply.read()
+    }
+
+    fn get_selinux_context(&self) -> binder::Result<String> {
+        let reply = self.binder.transact(
+            TestTransactionCode::GetSelinuxContext as TransactionCode,
+            0,
+            |_| Ok(()),
+        )?;
         reply.read()
     }
 }
@@ -125,12 +167,19 @@
     fn test(&self) -> binder::Result<String> {
         self.0.test()
     }
+
+    fn get_selinux_context(&self) -> binder::Result<String> {
+        self.0.get_selinux_context()
+    }
 }
 
 #[cfg(test)]
 mod tests {
+    use selinux_bindgen as selinux_sys;
+    use std::ffi::CStr;
     use std::fs::File;
     use std::process::{Child, Command};
+    use std::ptr;
     use std::sync::atomic::{AtomicBool, Ordering};
     use std::sync::Arc;
     use std::thread;
@@ -203,6 +252,24 @@
         assert_eq!(test_client.test().unwrap(), "trivial_client_test");
     }
 
+    #[test]
+    fn get_selinux_context() {
+        let service_name = "get_selinux_context";
+        let _process = ScopedServiceProcess::new(service_name);
+        let test_client: Box<dyn ITest> =
+            binder::get_interface(service_name).expect("Did not get manager binder service");
+        let expected_context = unsafe {
+            let mut out_ptr = ptr::null_mut();
+            assert_eq!(selinux_sys::getcon(&mut out_ptr), 0);
+            assert!(!out_ptr.is_null());
+            CStr::from_ptr(out_ptr)
+        };
+        assert_eq!(
+            test_client.get_selinux_context().unwrap(),
+            expected_context.to_str().expect("context was invalid UTF-8"),
+        );
+    }
+
     fn register_death_notification(binder: &mut SpIBinder) -> (Arc<AtomicBool>, DeathRecipient) {
         let binder_died = Arc::new(AtomicBool::new(false));