<commit_before>// Copyright 2013-2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

//! Interfaces to the operating system provided random number
//! generators.

pub use self::imp::OsRng;

#[cfg(all(unix, not(target_os = "ios")))]
mod imp {
    use prelude::v1::*;
    use self::OsRngInner::*;

    use libc;
    use mem;
    use old_io::{IoResult, File};
    use old_path::Path;
    use rand::Rng;
    use rand::reader::ReaderRng;
    use sys::os::errno;

    #[cfg(all(target_os = "linux",
              any(target_arch = "x86_64",
                  target_arch = "x86",
                  target_arch = "arm",
                  target_arch = "aarch64",
                  target_arch = "powerpc")))]
    fn getrandom(buf: &mut [u8]) -> libc::c_long {
        extern "C" {
            fn syscall(number: libc::c_long, ...) -> libc::c_long;
        }

        #[cfg(target_arch = "x86_64")]
        const NR_GETRANDOM: libc::c_long = 318;
        #[cfg(target_arch = "x86")]
        const NR_GETRANDOM: libc::c_long = 355;
        #[cfg(any(target_arch = "arm", target_arch = "aarch64"))]
        const NR_GETRANDOM: libc::c_long = 384;
        #[cfg(target_arch = "powerpc")]
        const NR_GETRANDOM: libc::c_long = 384;

        unsafe {
            syscall(NR_GETRANDOM, buf.as_mut_ptr(), buf.len(), 0)
        }
    }

    #[cfg(not(all(target_os = "linux",
                  any(target_arch = "x86_64",
                      target_arch = "x86",
                      target_arch = "arm",
                      target_arch = "aarch64",
                      target_arch = "powerpc"))))]
    fn getrandom(_buf: &mut [u8]) -> libc::c_long { -1 }

    fn getrandom_fill_bytes(v: &mut [u8]) {
        let mut read = 0;
        let len = v.len();
        while read < len {
            let result = getrandom(&mut v[read..]);
            if result == -1 {
                let err = errno() as libc::c_int;
                if err == libc::EINTR {
                    continue;
                } else {
                    panic!("unexpected getrandom error: {}", err);
                }
            } else {
                read += result as usize;
            }
        }
    }

    fn getrandom_next_u32() -> u32 {
        let mut buf: [u8; 4] = [0; 4];
        getrandom_fill_bytes(&mut buf);
        unsafe { mem::transmute::<[u8; 4], u32>(buf) }
    }

    fn getrandom_next_u64() -> u64 {
        let mut buf: [u8; 8] = [0; 8];
        getrandom_fill_bytes(&mut buf);
        unsafe { mem::transmute::<[u8; 8], u64>(buf) }
    }

    #[cfg(all(target_os = "linux",
              any(target_arch = "x86_64",
                  target_arch = "x86",
                  target_arch = "arm",
                  target_arch = "aarch64",
                  target_arch = "powerpc")))]
    fn is_getrandom_available() -> bool {
        use sync::atomic::{AtomicBool, ATOMIC_BOOL_INIT, Ordering};

        static GETRANDOM_CHECKED: AtomicBool = ATOMIC_BOOL_INIT;
        static GETRANDOM_AVAILABLE: AtomicBool = ATOMIC_BOOL_INIT;

        if !GETRANDOM_CHECKED.load(Ordering::Relaxed) {
            let mut buf: [u8; 0] = [];
            let result = getrandom(&mut buf);
            let available = if result == -1 {
                let err = errno() as libc::c_int;
                err != libc::ENOSYS
            } else {
                true
            };
            GETRANDOM_AVAILABLE.store(available, Ordering::Relaxed);
            GETRANDOM_CHECKED.store(true, Ordering::Relaxed);
            available
        } else {
            GETRANDOM_AVAILABLE.load(Ordering::Relaxed)
        }
    }

    #[cfg(not(all(target_os = "linux",
                  any(target_arch = "x86_64",
                      target_arch = "x86",
                      target_arch = "arm",
                      target_arch = "aarch64",
                      target_arch = "powerpc"))))]
    fn is_getrandom_available() -> bool { false }

    /// A random number generator that retrieves randomness straight from
    /// the operating system. Platform sources:
    ///
    /// - Unix-like systems (Linux, Android, Mac OSX): read directly from
    ///   `/dev/urandom`, or from `getrandom(2)` system call if available.
    /// - Windows: calls `CryptGenRandom`, using the default cryptographic
    ///   service provider with the `PROV_RSA_FULL` type.
    /// - iOS: calls SecRandomCopyBytes as /dev/(u)random is sandboxed.
    ///
    /// This does not block.
    pub struct OsRng {
        inner: OsRngInner,
    }

    enum OsRngInner {
        OsGetrandomRng,
        OsReaderRng(ReaderRng<File>),
    }

    impl OsRng {
        /// Create a new `OsRng`.
        pub fn new() -> IoResult<OsRng> {
            if is_getrandom_available() {
                return Ok(OsRng { inner: OsGetrandomRng });
            }

            let reader = try!(File::open(&Path::new("/dev/urandom")));
            let reader_rng = ReaderRng::new(reader);

            Ok(OsRng { inner: OsReaderRng(reader_rng) })
        }
    }

    impl Rng for OsRng {
        fn next_u32(&mut self) -> u32 {
            match self.inner {
                OsGetrandomRng => getrandom_next_u32(),
                OsReaderRng(ref mut rng) => rng.next_u32(),
            }
        }
        fn next_u64(&mut self) -> u64 {
            match self.inner {
                OsGetrandomRng => getrandom_next_u64(),
                OsReaderRng(ref mut rng) => rng.next_u64(),
            }
        }
        fn fill_bytes(&mut self, v: &mut [u8]) {
            match self.inner {
                OsGetrandomRng => getrandom_fill_bytes(v),
                OsReaderRng(ref mut rng) => rng.fill_bytes(v)
            }
        }
    }
}

#[cfg(target_os = "ios")]
mod imp {
    use prelude::v1::*;

    use old_io::IoResult;
    use mem;
    use os;
    use rand::Rng;
    use libc::{c_int, size_t};

    /// A random number generator that retrieves randomness straight from
    /// the operating system. Platform sources:
    ///
    /// - Unix-like systems (Linux, Android, Mac OSX): read directly from
    ///   `/dev/urandom`, or from `getrandom(2)` system call if available.
    /// - Windows: calls `CryptGenRandom`, using the default cryptographic
    ///   service provider with the `PROV_RSA_FULL` type.
    /// - iOS: calls SecRandomCopyBytes as /dev/(u)random is sandboxed.
    ///
    /// This does not block.
    pub struct OsRng {
        // dummy field to ensure that this struct cannot be constructed outside of this module
        _dummy: (),
    }

    #[repr(C)]
    struct SecRandom;

    #[allow(non_upper_case_globals)]
    const kSecRandomDefault: *const SecRandom = 0 as *const SecRandom;

    #[link(name = "Security", kind = "framework")]
    extern "C" {
        fn SecRandomCopyBytes(rnd: *const SecRandom,
                              count: size_t, bytes: *mut u8) -> c_int;
    }

    impl OsRng {
        /// Create a new `OsRng`.
        pub fn new() -> IoResult<OsRng> {
            Ok(OsRng { _dummy: () })
        }
    }

    impl Rng for OsRng {
        fn next_u32(&mut self) -> u32 {
            let mut v = [0; 4];
            self.fill_bytes(&mut v);
            unsafe { mem::transmute(v) }
        }
        fn next_u64(&mut self) -> u64 {
            let mut v = [0; 8];
            self.fill_bytes(&mut v);
            unsafe { mem::transmute(v) }
        }
        fn fill_bytes(&mut self, v: &mut [u8]) {
            let ret = unsafe {
                SecRandomCopyBytes(kSecRandomDefault, v.len() as size_t, v.as_mut_ptr())
            };
            if ret == -1 {
                panic!("couldn't generate random bytes: {}", os::last_os_error());
            }
        }
    }
}

#[cfg(windows)]
mod imp {
    use prelude::v1::*;

    use io;
    use mem;
    use old_io::{IoResult, IoError};
    use rand::Rng;
    use libc::types::os::arch::extra::{LONG_PTR};
    use libc::{DWORD, BYTE, LPCSTR, BOOL};

    type HCRYPTPROV = LONG_PTR;

    /// A random number generator that retrieves randomness straight from
    /// the operating system. Platform sources:
    ///
    /// - Unix-like systems (Linux, Android, Mac OSX): read directly from
    ///   `/dev/urandom`, or from `getrandom(2)` system call if available.
    /// - Windows: calls `CryptGenRandom`, using the default cryptographic
    ///   service provider with the `PROV_RSA_FULL` type.
    /// - iOS: calls SecRandomCopyBytes as /dev/(u)random is sandboxed.
    ///
    /// This does not block.
    pub struct OsRng {
        hcryptprov: HCRYPTPROV
    }

    const PROV_RSA_FULL: DWORD = 1;
    const CRYPT_SILENT: DWORD = 64;
    const CRYPT_VERIFYCONTEXT: DWORD = 0xF0000000;

    #[allow(non_snake_case)]
    extern "system" {
        fn CryptAcquireContextA(phProv: *mut HCRYPTPROV,
                                pszContainer: LPCSTR,
                                pszProvider: LPCSTR,
                                dwProvType: DWORD,
                                dwFlags: DWORD) -> BOOL;
        fn CryptGenRandom(hProv: HCRYPTPROV,
                          dwLen: DWORD,
                          pbBuffer: *mut BYTE) -> BOOL;
        fn CryptReleaseContext(hProv: HCRYPTPROV, dwFlags: DWORD) -> BOOL;
    }

    impl OsRng {
        /// Create a new `OsRng`.
        pub fn new() -> IoResult<OsRng> {
            let mut hcp = 0;
            let ret = unsafe {
                CryptAcquireContextA(&mut hcp, 0 as LPCSTR, 0 as LPCSTR,
                                     PROV_RSA_FULL,
                                     CRYPT_VERIFYCONTEXT | CRYPT_SILENT)
            };

            if ret == 0 {
                Err(IoError::last_error())
            } else {
                Ok(OsRng { hcryptprov: hcp })
            }
        }
    }

    impl Rng for OsRng {
        fn next_u32(&mut self) -> u32 {
            let mut v = [0; 4];
            self.fill_bytes(&mut v);
            unsafe { mem::transmute(v) }
        }
        fn next_u64(&mut self) -> u64 {
            let mut v = [0; 8];
            self.fill_bytes(&mut v);
            unsafe { mem::transmute(v) }
        }
        fn fill_bytes(&mut self, v: &mut [u8]) {
            let ret = unsafe {
                CryptGenRandom(self.hcryptprov, v.len() as DWORD,
                               v.as_mut_ptr())
            };
            if ret == 0 {
                panic!("couldn't generate random bytes: {}",
                       io::Error::last_os_error());
            }
        }
    }

    impl Drop for OsRng {
        fn drop(&mut self) {
            let ret = unsafe {
                CryptReleaseContext(self.hcryptprov, 0)
            };
            if ret == 0 {
                panic!("couldn't release context: {}",
                       io::Error::last_os_error());
            }
        }
    }
}

#[cfg(test)]
mod test {
    use prelude::v1::*;

    use sync::mpsc::channel;
    use rand::Rng;
    use super::OsRng;
    use thread;

    #[test]
    fn test_os_rng() {
        let mut r = OsRng::new().unwrap();

        r.next_u32();
        r.next_u64();

        let mut v = [0; 1000];
        r.fill_bytes(&mut v);
    }

    #[test]
    fn test_os_rng_tasks() {

        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();

                // deschedule to attempt to interleave things as much
                // as possible (XXX: is this a good test?)
                let mut r = OsRng::new().unwrap();
                thread::yield_now();
                let mut v = [0; 1000];

                for _ in 0..100 {
                    r.next_u32();
                    thread::yield_now();
                    r.next_u64();
                    thread::yield_now();
                    r.fill_bytes(&mut v);
                    thread::yield_now();
                }
            });
        }

        // start all the tasks
        for tx in &txs {
            tx.send(()).unwrap();
        }
    }
}
<commit_msg>iOS: os::last_os_error fallout<commit_after>// Copyright 2013-2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

//! Interfaces to the operating system provided random number
//! generators.

pub use self::imp::OsRng;

#[cfg(all(unix, not(target_os = "ios")))]
mod imp {
    use prelude::v1::*;
    use self::OsRngInner::*;

    use libc;
    use mem;
    use old_io::{IoResult, File};
    use old_path::Path;
    use rand::Rng;
    use rand::reader::ReaderRng;
    use sys::os::errno;

    #[cfg(all(target_os = "linux",
              any(target_arch = "x86_64",
                  target_arch = "x86",
                  target_arch = "arm",
                  target_arch = "aarch64",
                  target_arch = "powerpc")))]
    fn getrandom(buf: &mut [u8]) -> libc::c_long {
        extern "C" {
            fn syscall(number: libc::c_long, ...) -> libc::c_long;
        }

        #[cfg(target_arch = "x86_64")]
        const NR_GETRANDOM: libc::c_long = 318;
        #[cfg(target_arch = "x86")]
        const NR_GETRANDOM: libc::c_long = 355;
        #[cfg(any(target_arch = "arm", target_arch = "aarch64"))]
        const NR_GETRANDOM: libc::c_long = 384;
        #[cfg(target_arch = "powerpc")]
        const NR_GETRANDOM: libc::c_long = 384;

        unsafe {
            syscall(NR_GETRANDOM, buf.as_mut_ptr(), buf.len(), 0)
        }
    }

    #[cfg(not(all(target_os = "linux",
                  any(target_arch = "x86_64",
                      target_arch = "x86",
                      target_arch = "arm",
                      target_arch = "aarch64",
                      target_arch = "powerpc"))))]
    fn getrandom(_buf: &mut [u8]) -> libc::c_long { -1 }

    fn getrandom_fill_bytes(v: &mut [u8]) {
        let mut read = 0;
        let len = v.len();
        while read < len {
            let result = getrandom(&mut v[read..]);
            if result == -1 {
                let err = errno() as libc::c_int;
                if err == libc::EINTR {
                    continue;
                } else {
                    panic!("unexpected getrandom error: {}", err);
                }
            } else {
                read += result as usize;
            }
        }
    }

    fn getrandom_next_u32() -> u32 {
        let mut buf: [u8; 4] = [0; 4];
        getrandom_fill_bytes(&mut buf);
        unsafe { mem::transmute::<[u8; 4], u32>(buf) }
    }

    fn getrandom_next_u64() -> u64 {
        let mut buf: [u8; 8] = [0; 8];
        getrandom_fill_bytes(&mut buf);
        unsafe { mem::transmute::<[u8; 8], u64>(buf) }
    }

    #[cfg(all(target_os = "linux",
              any(target_arch = "x86_64",
                  target_arch = "x86",
                  target_arch = "arm",
                  target_arch = "aarch64",
                  target_arch = "powerpc")))]
    fn is_getrandom_available() -> bool {
        use sync::atomic::{AtomicBool, ATOMIC_BOOL_INIT, Ordering};

        static GETRANDOM_CHECKED: AtomicBool = ATOMIC_BOOL_INIT;
        static GETRANDOM_AVAILABLE: AtomicBool = ATOMIC_BOOL_INIT;

        if !GETRANDOM_CHECKED.load(Ordering::Relaxed) {
            let mut buf: [u8; 0] = [];
            let result = getrandom(&mut buf);
            let available = if result == -1 {
                let err = errno() as libc::c_int;
                err != libc::ENOSYS
            } else {
                true
            };
            GETRANDOM_AVAILABLE.store(available, Ordering::Relaxed);
            GETRANDOM_CHECKED.store(true, Ordering::Relaxed);
            available
        } else {
            GETRANDOM_AVAILABLE.load(Ordering::Relaxed)
        }
    }

    #[cfg(not(all(target_os = "linux",
                  any(target_arch = "x86_64",
                      target_arch = "x86",
                      target_arch = "arm",
                      target_arch = "aarch64",
                      target_arch = "powerpc"))))]
    fn is_getrandom_available() -> bool { false }

    /// A random number generator that retrieves randomness straight from
    /// the operating system. Platform sources:
    ///
    /// - Unix-like systems (Linux, Android, Mac OSX): read directly from
    ///   `/dev/urandom`, or from `getrandom(2)` system call if available.
    /// - Windows: calls `CryptGenRandom`, using the default cryptographic
    ///   service provider with the `PROV_RSA_FULL` type.
    /// - iOS: calls SecRandomCopyBytes as /dev/(u)random is sandboxed.
    ///
    /// This does not block.
    pub struct OsRng {
        inner: OsRngInner,
    }

    enum OsRngInner {
        OsGetrandomRng,
        OsReaderRng(ReaderRng<File>),
    }

    impl OsRng {
        /// Create a new `OsRng`.
        pub fn new() -> IoResult<OsRng> {
            if is_getrandom_available() {
                return Ok(OsRng { inner: OsGetrandomRng });
            }

            let reader = try!(File::open(&Path::new("/dev/urandom")));
            let reader_rng = ReaderRng::new(reader);

            Ok(OsRng { inner: OsReaderRng(reader_rng) })
        }
    }

    impl Rng for OsRng {
        fn next_u32(&mut self) -> u32 {
            match self.inner {
                OsGetrandomRng => getrandom_next_u32(),
                OsReaderRng(ref mut rng) => rng.next_u32(),
            }
        }
        fn next_u64(&mut self) -> u64 {
            match self.inner {
                OsGetrandomRng => getrandom_next_u64(),
                OsReaderRng(ref mut rng) => rng.next_u64(),
            }
        }
        fn fill_bytes(&mut self, v: &mut [u8]) {
            match self.inner {
                OsGetrandomRng => getrandom_fill_bytes(v),
                OsReaderRng(ref mut rng) => rng.fill_bytes(v)
            }
        }
    }
}

#[cfg(target_os = "ios")]
mod imp {
    use prelude::v1::*;

    use io;
    use old_io::IoResult;
    use mem;
    use rand::Rng;
    use libc::{c_int, size_t};

    /// A random number generator that retrieves randomness straight from
    /// the operating system. Platform sources:
    ///
    /// - Unix-like systems (Linux, Android, Mac OSX): read directly from
    ///   `/dev/urandom`, or from `getrandom(2)` system call if available.
    /// - Windows: calls `CryptGenRandom`, using the default cryptographic
    ///   service provider with the `PROV_RSA_FULL` type.
    /// - iOS: calls SecRandomCopyBytes as /dev/(u)random is sandboxed.
    ///
    /// This does not block.
    pub struct OsRng {
        // dummy field to ensure that this struct cannot be constructed outside of this module
        _dummy: (),
    }

    #[repr(C)]
    struct SecRandom;

    #[allow(non_upper_case_globals)]
    const kSecRandomDefault: *const SecRandom = 0 as *const SecRandom;

    #[link(name = "Security", kind = "framework")]
    extern "C" {
        fn SecRandomCopyBytes(rnd: *const SecRandom,
                              count: size_t, bytes: *mut u8) -> c_int;
    }

    impl OsRng {
        /// Create a new `OsRng`.
        pub fn new() -> IoResult<OsRng> {
            Ok(OsRng { _dummy: () })
        }
    }

    impl Rng for OsRng {
        fn next_u32(&mut self) -> u32 {
            let mut v = [0; 4];
            self.fill_bytes(&mut v);
            unsafe { mem::transmute(v) }
        }
        fn next_u64(&mut self) -> u64 {
            let mut v = [0; 8];
            self.fill_bytes(&mut v);
            unsafe { mem::transmute(v) }
        }
        fn fill_bytes(&mut self, v: &mut [u8]) {
            let ret = unsafe {
                SecRandomCopyBytes(kSecRandomDefault, v.len() as size_t, v.as_mut_ptr())
            };
            if ret == -1 {
                panic!("couldn't generate random bytes: {}", io::Error::last_os_error());
            }
        }
    }
}

#[cfg(windows)]
mod imp {
    use prelude::v1::*;

    use io;
    use mem;
    use old_io::{IoResult, IoError};
    use rand::Rng;
    use libc::types::os::arch::extra::{LONG_PTR};
    use libc::{DWORD, BYTE, LPCSTR, BOOL};

    type HCRYPTPROV = LONG_PTR;

    /// A random number generator that retrieves randomness straight from
    /// the operating system. Platform sources:
    ///
    /// - Unix-like systems (Linux, Android, Mac OSX): read directly from
    ///   `/dev/urandom`, or from `getrandom(2)` system call if available.
    /// - Windows: calls `CryptGenRandom`, using the default cryptographic
    ///   service provider with the `PROV_RSA_FULL` type.
    /// - iOS: calls SecRandomCopyBytes as /dev/(u)random is sandboxed.
    ///
    /// This does not block.
    pub struct OsRng {
        hcryptprov: HCRYPTPROV
    }

    const PROV_RSA_FULL: DWORD = 1;
    const CRYPT_SILENT: DWORD = 64;
    const CRYPT_VERIFYCONTEXT: DWORD = 0xF0000000;

    #[allow(non_snake_case)]
    extern "system" {
        fn CryptAcquireContextA(phProv: *mut HCRYPTPROV,
                                pszContainer: LPCSTR,
                                pszProvider: LPCSTR,
                                dwProvType: DWORD,
                                dwFlags: DWORD) -> BOOL;
        fn CryptGenRandom(hProv: HCRYPTPROV,
                          dwLen: DWORD,
                          pbBuffer: *mut BYTE) -> BOOL;
        fn CryptReleaseContext(hProv: HCRYPTPROV, dwFlags: DWORD) -> BOOL;
    }

    impl OsRng {
        /// Create a new `OsRng`.
        pub fn new() -> IoResult<OsRng> {
            let mut hcp = 0;
            let ret = unsafe {
                CryptAcquireContextA(&mut hcp, 0 as LPCSTR, 0 as LPCSTR,
                                     PROV_RSA_FULL,
                                     CRYPT_VERIFYCONTEXT | CRYPT_SILENT)
            };

            if ret == 0 {
                Err(IoError::last_error())
            } else {
                Ok(OsRng { hcryptprov: hcp })
            }
        }
    }

    impl Rng for OsRng {
        fn next_u32(&mut self) -> u32 {
            let mut v = [0; 4];
            self.fill_bytes(&mut v);
            unsafe { mem::transmute(v) }
        }
        fn next_u64(&mut self) -> u64 {
            let mut v = [0; 8];
            self.fill_bytes(&mut v);
            unsafe { mem::transmute(v) }
        }
        fn fill_bytes(&mut self, v: &mut [u8]) {
            let ret = unsafe {
                CryptGenRandom(self.hcryptprov, v.len() as DWORD,
                               v.as_mut_ptr())
            };
            if ret == 0 {
                panic!("couldn't generate random bytes: {}",
                       io::Error::last_os_error());
            }
        }
    }

    impl Drop for OsRng {
        fn drop(&mut self) {
            let ret = unsafe {
                CryptReleaseContext(self.hcryptprov, 0)
            };
            if ret == 0 {
                panic!("couldn't release context: {}",
                       io::Error::last_os_error());
            }
        }
    }
}

#[cfg(test)]
mod test {
    use prelude::v1::*;

    use sync::mpsc::channel;
    use rand::Rng;
    use super::OsRng;
    use thread;

    #[test]
    fn test_os_rng() {
        let mut r = OsRng::new().unwrap();

        r.next_u32();
        r.next_u64();

        let mut v = [0; 1000];
        r.fill_bytes(&mut v);
    }

    #[test]
    fn test_os_rng_tasks() {

        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();

                // deschedule to attempt to interleave things as much
                // as possible (XXX: is this a good test?)
                let mut r = OsRng::new().unwrap();
                thread::yield_now();
                let mut v = [0; 1000];

                for _ in 0..100 {
                    r.next_u32();
                    thread::yield_now();
                    r.next_u64();
                    thread::yield_now();
                    r.fill_bytes(&mut v);
                    thread::yield_now();
                }
            });
        }

        // start all the tasks
        for tx in &txs {
            tx.send(()).unwrap();
        }
    }
}
<|endoftext|>


<commit_before>// Copyright 2013-2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

//! Interfaces to the operating system provided random number
//! generators.

pub use self::imp::OsRng;

#[cfg(all(unix, not(target_os = "ios"), not(target_os = "openbsd")))]
mod imp {
    use self::OsRngInner::*;

    use fs::File;
    use io;
    use libc;
    use mem;
    use rand::Rng;
    use rand::reader::ReaderRng;
    use sys::os::errno;

    #[cfg(all(target_os = "linux",
              any(target_arch = "x86_64",
                  target_arch = "x86",
                  target_arch = "arm",
                  target_arch = "aarch64",
                  target_arch = "powerpc")))]
    fn getrandom(buf: &mut [u8]) -> libc::c_long {
        #[cfg(target_arch = "x86_64")]
        const NR_GETRANDOM: libc::c_long = 318;
        #[cfg(target_arch = "x86")]
        const NR_GETRANDOM: libc::c_long = 355;
        #[cfg(any(target_arch = "arm", target_arch = "powerpc"))]
        const NR_GETRANDOM: libc::c_long = 384;
        #[cfg(target_arch = "aarch64")]
        const NR_GETRANDOM: libc::c_long = 278;

        unsafe {
            libc::syscall(NR_GETRANDOM, buf.as_mut_ptr(), buf.len(), 0)
        }
    }

    #[cfg(not(all(target_os = "linux",
                  any(target_arch = "x86_64",
                      target_arch = "x86",
                      target_arch = "arm",
                      target_arch = "aarch64",
                      target_arch = "powerpc"))))]
    fn getrandom(_buf: &mut [u8]) -> libc::c_long { -1 }

    fn getrandom_fill_bytes(v: &mut [u8]) {
        let mut read = 0;
        while read < v.len() {
            let result = getrandom(&mut v[read..]);
            if result == -1 {
                let err = errno() as libc::c_int;
                if err == libc::EINTR {
                    continue;
                } else {
                    panic!("unexpected getrandom error: {}", err);
                }
            } else {
                read += result as usize;
            }
        }
    }

    fn getrandom_next_u32() -> u32 {
        let mut buf: [u8; 4] = [0; 4];
        getrandom_fill_bytes(&mut buf);
        unsafe { mem::transmute::<[u8; 4], u32>(buf) }
    }

    fn getrandom_next_u64() -> u64 {
        let mut buf: [u8; 8] = [0; 8];
        getrandom_fill_bytes(&mut buf);
        unsafe { mem::transmute::<[u8; 8], u64>(buf) }
    }

    #[cfg(all(target_os = "linux",
              any(target_arch = "x86_64",
                  target_arch = "x86",
                  target_arch = "arm",
                  target_arch = "aarch64",
                  target_arch = "powerpc")))]
    fn is_getrandom_available() -> bool {
        use sync::atomic::{AtomicBool, Ordering};
        use sync::Once;

        static CHECKER: Once = Once::new();
        static AVAILABLE: AtomicBool = AtomicBool::new(false);

        CHECKER.call_once(|| {
            let mut buf: [u8; 0] = [];
            let result = getrandom(&mut buf);
            let available = if result == -1 {
                let err = io::Error::last_os_error().raw_os_error();
                err != Some(libc::ENOSYS)
            } else {
                true
            };
            AVAILABLE.store(available, Ordering::Relaxed);
        });

        AVAILABLE.load(Ordering::Relaxed)
    }

    #[cfg(not(all(target_os = "linux",
                  any(target_arch = "x86_64",
                      target_arch = "x86",
                      target_arch = "arm",
                      target_arch = "aarch64",
                      target_arch = "powerpc"))))]
    fn is_getrandom_available() -> bool { false }

    /// A random number generator that retrieves randomness straight from
    /// the operating system. Platform sources:
    ///
    /// - Unix-like systems (Linux, Android, Mac OSX): read directly from
    ///   `/dev/urandom`, or from `getrandom(2)` system call if available.
    /// - Windows: calls `CryptGenRandom`, using the default cryptographic
    ///   service provider with the `PROV_RSA_FULL` type.
    /// - iOS: calls SecRandomCopyBytes as /dev/(u)random is sandboxed.
    /// - OpenBSD: uses the `getentropy(2)` system call.
    ///
    /// This does not block.
    pub struct OsRng {
        inner: OsRngInner,
    }

    enum OsRngInner {
        OsGetrandomRng,
        OsReaderRng(ReaderRng<File>),
    }

    impl OsRng {
        /// Create a new `OsRng`.
        pub fn new() -> io::Result<OsRng> {
            if is_getrandom_available() {
                return Ok(OsRng { inner: OsGetrandomRng });
            }

            let reader = try!(File::open("/dev/urandom"));
            let reader_rng = ReaderRng::new(reader);

            Ok(OsRng { inner: OsReaderRng(reader_rng) })
        }
    }

    impl Rng for OsRng {
        fn next_u32(&mut self) -> u32 {
            match self.inner {
                OsGetrandomRng => getrandom_next_u32(),
                OsReaderRng(ref mut rng) => rng.next_u32(),
            }
        }
        fn next_u64(&mut self) -> u64 {
            match self.inner {
                OsGetrandomRng => getrandom_next_u64(),
                OsReaderRng(ref mut rng) => rng.next_u64(),
            }
        }
        fn fill_bytes(&mut self, v: &mut [u8]) {
            match self.inner {
                OsGetrandomRng => getrandom_fill_bytes(v),
                OsReaderRng(ref mut rng) => rng.fill_bytes(v)
            }
        }
    }
}

#[cfg(target_os = "openbsd")]
mod imp {
    use io;
    use libc;
    use mem;
    use sys::os::errno;
    use rand::Rng;

    /// A random number generator that retrieves randomness straight from
    /// the operating system. Platform sources:
    ///
    /// - Unix-like systems (Linux, Android, Mac OSX): read directly from
    ///   `/dev/urandom`, or from `getrandom(2)` system call if available.
    /// - Windows: calls `CryptGenRandom`, using the default cryptographic
    ///   service provider with the `PROV_RSA_FULL` type.
    /// - iOS: calls SecRandomCopyBytes as /dev/(u)random is sandboxed.
    /// - OpenBSD: uses the `getentropy(2)` system call.
    ///
    /// This does not block.
    pub struct OsRng {
        // dummy field to ensure that this struct cannot be constructed outside
        // of this module
        _dummy: (),
    }

    impl OsRng {
        /// Create a new `OsRng`.
        pub fn new() -> io::Result<OsRng> {
            Ok(OsRng { _dummy: () })
        }
    }

    impl Rng for OsRng {
        fn next_u32(&mut self) -> u32 {
            let mut v = [0; 4];
            self.fill_bytes(&mut v);
            unsafe { mem::transmute(v) }
        }
        fn next_u64(&mut self) -> u64 {
            let mut v = [0; 8];
            self.fill_bytes(&mut v);
            unsafe { mem::transmute(v) }
        }
        fn fill_bytes(&mut self, v: &mut [u8]) {
            // getentropy(2) permits a maximum buffer size of 256 bytes
            for s in v.chunks_mut(256) {
                let ret = unsafe {
                    libc::syscall(libc::NR_GETENTROPY, s.as_mut_ptr(), s.len())
                };
                if ret == -1 {
                    panic!("unexpected getentropy error: {}", errno());
                }
            }
        }
    }
}

#[cfg(target_os = "ios")]
mod imp {
    use io;
    use mem;
    use ptr;
    use rand::Rng;
    use libc::{c_int, size_t};

    /// A random number generator that retrieves randomness straight from
    /// the operating system. Platform sources:
    ///
    /// - Unix-like systems (Linux, Android, Mac OSX): read directly from
    ///   `/dev/urandom`, or from `getrandom(2)` system call if available.
    /// - Windows: calls `CryptGenRandom`, using the default cryptographic
    ///   service provider with the `PROV_RSA_FULL` type.
    /// - iOS: calls SecRandomCopyBytes as /dev/(u)random is sandboxed.
    /// - OpenBSD: uses the `getentropy(2)` system call.
    ///
    /// This does not block.
    pub struct OsRng {
        // dummy field to ensure that this struct cannot be constructed outside
        // of this module
        _dummy: (),
    }

    enum SecRandom {}

    #[allow(non_upper_case_globals)]
    const kSecRandomDefault: *const SecRandom = ptr::null();

    #[link(name = "Security", kind = "framework")]
    extern "C" {
        fn SecRandomCopyBytes(rnd: *const SecRandom,
                              count: size_t, bytes: *mut u8) -> c_int;
    }

    impl OsRng {
        /// Create a new `OsRng`.
        pub fn new() -> io::Result<OsRng> {
            Ok(OsRng { _dummy: () })
        }
    }

    impl Rng for OsRng {
        fn next_u32(&mut self) -> u32 {
            let mut v = [0; 4];
            self.fill_bytes(&mut v);
            unsafe { mem::transmute(v) }
        }
        fn next_u64(&mut self) -> u64 {
            let mut v = [0; 8];
            self.fill_bytes(&mut v);
            unsafe { mem::transmute(v) }
        }
        fn fill_bytes(&mut self, v: &mut [u8]) {
            let ret = unsafe {
                SecRandomCopyBytes(kSecRandomDefault, v.len() as size_t,
                                   v.as_mut_ptr())
            };
            if ret == -1 {
                panic!("couldn't generate random bytes: {}",
                       io::Error::last_os_error());
            }
        }
    }
}

#[cfg(windows)]
mod imp {
    use io;
    use mem;
    use rand::Rng;
    use sys::c;

    /// A random number generator that retrieves randomness straight from
    /// the operating system. Platform sources:
    ///
    /// - Unix-like systems (Linux, Android, Mac OSX): read directly from
    ///   `/dev/urandom`, or from `getrandom(2)` system call if available.
    /// - Windows: calls `CryptGenRandom`, using the default cryptographic
    ///   service provider with the `PROV_RSA_FULL` type.
    /// - iOS: calls SecRandomCopyBytes as /dev/(u)random is sandboxed.
    /// - OpenBSD: uses the `getentropy(2)` system call.
    ///
    /// This does not block.
    pub struct OsRng {
        hcryptprov: c::HCRYPTPROV
    }

    impl OsRng {
        /// Create a new `OsRng`.
        pub fn new() -> io::Result<OsRng> {
            let mut hcp = 0;
            let ret = unsafe {
                c::CryptAcquireContextA(&mut hcp, 0 as c::LPCSTR, 0 as c::LPCSTR,
                                        c::PROV_RSA_FULL,
                                        c::CRYPT_VERIFYCONTEXT | c::CRYPT_SILENT)
            };

            if ret == 0 {
                Err(io::Error::last_os_error())
            } else {
                Ok(OsRng { hcryptprov: hcp })
            }
        }
    }

    impl Rng for OsRng {
        fn next_u32(&mut self) -> u32 {
            let mut v = [0; 4];
            self.fill_bytes(&mut v);
            unsafe { mem::transmute(v) }
        }
        fn next_u64(&mut self) -> u64 {
            let mut v = [0; 8];
            self.fill_bytes(&mut v);
            unsafe { mem::transmute(v) }
        }
        fn fill_bytes(&mut self, v: &mut [u8]) {
            let ret = unsafe {
                c::CryptGenRandom(self.hcryptprov, v.len() as c::DWORD,
                                  v.as_mut_ptr())
            };
            if ret == 0 {
                panic!("couldn't generate random bytes: {}",
                       io::Error::last_os_error());
            }
        }
    }

    impl Drop for OsRng {
        fn drop(&mut self) {
            let ret = unsafe {
                c::CryptReleaseContext(self.hcryptprov, 0)
            };
            if ret == 0 {
                panic!("couldn't release context: {}",
                       io::Error::last_os_error());
            }
        }
    }
}

#[cfg(test)]
mod tests {
    use sync::mpsc::channel;
    use rand::Rng;
    use super::OsRng;
    use thread;

    #[test]
    fn test_os_rng() {
        let mut r = OsRng::new().unwrap();

        r.next_u32();
        r.next_u64();

        let mut v = [0; 1000];
        r.fill_bytes(&mut v);
    }

    #[test]
    fn test_os_rng_tasks() {

        let mut txs = vec!();
        for _ in 0..20 {
            let (tx, rx) = channel();
            txs.push(tx);

            thread::spawn(move|| {
                // wait until all the threads are ready to go.
                rx.recv().unwrap();

                // deschedule to attempt to interleave things as much
                // as possible (XXX: is this a good test?)
                let mut r = OsRng::new().unwrap();
                thread::yield_now();
                let mut v = [0; 1000];

                for _ in 0..100 {
                    r.next_u32();
                    thread::yield_now();
                    r.next_u64();
                    thread::yield_now();
                    r.fill_bytes(&mut v);
                    thread::yield_now();
                }
            });
        }

        // start all the threads
        for tx in &txs {
            tx.send(()).unwrap();
        }
    }
}
<commit_msg>switch from syscall(2) to getentropy(2)<commit_after>// Copyright 2013-2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

//! Interfaces to the operating system provided random number
//! generators.

pub use self::imp::OsRng;

#[cfg(all(unix, not(target_os = "ios"), not(target_os = "openbsd")))]
mod imp {
    use self::OsRngInner::*;

    use fs::File;
    use io;
    use libc;
    use mem;
    use rand::Rng;
    use rand::reader::ReaderRng;
    use sys::os::errno;

    #[cfg(all(target_os = "linux",
              any(target_arch = "x86_64",
                  target_arch = "x86",
                  target_arch = "arm",
                  target_arch = "aarch64",
                  target_arch = "powerpc")))]
    fn getrandom(buf: &mut [u8]) -> libc::c_long {
        #[cfg(target_arch = "x86_64")]
        const NR_GETRANDOM: libc::c_long = 318;
        #[cfg(target_arch = "x86")]
        const NR_GETRANDOM: libc::c_long = 355;
        #[cfg(any(target_arch = "arm", target_arch = "powerpc"))]
        const NR_GETRANDOM: libc::c_long = 384;
        #[cfg(target_arch = "aarch64")]
        const NR_GETRANDOM: libc::c_long = 278;

        unsafe {
            libc::syscall(NR_GETRANDOM, buf.as_mut_ptr(), buf.len(), 0)
        }
    }

    #[cfg(not(all(target_os = "linux",
                  any(target_arch = "x86_64",
                      target_arch = "x86",
                      target_arch = "arm",
                      target_arch = "aarch64",
                      target_arch = "powerpc"))))]
    fn getrandom(_buf: &mut [u8]) -> libc::c_long { -1 }

    fn getrandom_fill_bytes(v: &mut [u8]) {
        let mut read = 0;
        while read < v.len() {
            let result = getrandom(&mut v[read..]);
            if result == -1 {
                let err = errno() as libc::c_int;
                if err == libc::EINTR {
                    continue;
                } else {
                    panic!("unexpected getrandom error: {}", err);
                }
            } else {
                read += result as usize;
            }
        }
    }

    fn getrandom_next_u32() -> u32 {
        let mut buf: [u8; 4] = [0; 4];
        getrandom_fill_bytes(&mut buf);
        unsafe { mem::transmute::<[u8; 4], u32>(buf) }
    }

    fn getrandom_next_u64() -> u64 {
        let mut buf: [u8; 8] = [0; 8];
        getrandom_fill_bytes(&mut buf);
        unsafe { mem::transmute::<[u8; 8], u64>(buf) }
    }

    #[cfg(all(target_os = "linux",
              any(target_arch = "x86_64",
                  target_arch = "x86",
                  target_arch = "arm",
                  target_arch = "aarch64",
                  target_arch = "powerpc")))]
    fn is_getrandom_available() -> bool {
        use sync::atomic::{AtomicBool, Ordering};
        use sync::Once;

        static CHECKER: Once = Once::new();
        static AVAILABLE: AtomicBool = AtomicBool::new(false);

        CHECKER.call_once(|| {
            let mut buf: [u8; 0] = [];
            let result = getrandom(&mut buf);
            let available = if result == -1 {
                let err = io::Error::last_os_error().raw_os_error();
                err != Some(libc::ENOSYS)
            } else {
                true
            };
            AVAILABLE.store(available, Ordering::Relaxed);
        });

        AVAILABLE.load(Ordering::Relaxed)
    }

    #[cfg(not(all(target_os = "linux",
                  any(target_arch = "x86_64",
                      target_arch = "x86",
                      target_arch = "arm",
                      target_arch = "aarch64",
                      target_arch = "powerpc"))))]
    fn is_getrandom_available() -> bool { false }

    /// A random number generator that retrieves randomness straight from
    /// the operating system. Platform sources:
    ///
    /// - Unix-like systems (Linux, Android, Mac OSX): read directly from
    ///   `/dev/urandom`, or from `getrandom(2)` system call if available.
    /// - Windows: calls `CryptGenRandom`, using the default cryptographic
    ///   service provider with the `PROV_RSA_FULL` type.
    /// - iOS: calls SecRandomCopyBytes as /dev/(u)random is sandboxed.
    /// - OpenBSD: uses the `getentropy(2)` system call.
    ///
    /// This does not block.
    pub struct OsRng {
        inner: OsRngInner,
    }

    enum OsRngInner {
        OsGetrandomRng,
        OsReaderRng(ReaderRng<File>),
    }

    impl OsRng {
        /// Create a new `OsRng`.
        pub fn new() -> io::Result<OsRng> {
            if is_getrandom_available() {
                return Ok(OsRng { inner: OsGetrandomRng });
            }

            let reader = try!(File::open("/dev/urandom"));
            let reader_rng = ReaderRng::new(reader);

            Ok(OsRng { inner: OsReaderRng(reader_rng) })
        }
    }

    impl Rng for OsRng {
        fn next_u32(&mut self) -> u32 {
            match self.inner {
                OsGetrandomRng => getrandom_next_u32(),
                OsReaderRng(ref mut rng) => rng.next_u32(),
            }
        }
        fn next_u64(&mut self) -> u64 {
            match self.inner {
                OsGetrandomRng => getrandom_next_u64(),
                OsReaderRng(ref mut rng) => rng.next_u64(),
            }
        }
        fn fill_bytes(&mut self, v: &mut [u8]) {
            match self.inner {
                OsGetrandomRng => getrandom_fill_bytes(v),
                OsReaderRng(ref mut rng) => rng.fill_bytes(v)
            }
        }
    }
}

#[cfg(target_os = "openbsd")]
mod imp {
    use io;
    use libc;
    use mem;
    use sys::os::errno;
    use rand::Rng;

    /// A random number generator that retrieves randomness straight from
    /// the operating system. Platform sources:
    ///
    /// - Unix-like systems (Linux, Android, Mac OSX): read directly from
    ///   `/dev/urandom`, or from `getrandom(2)` system call if available.
    /// - Windows: calls `CryptGenRandom`, using the default cryptographic
    ///   service provider with the `PROV_RSA_FULL` type.
    /// - iOS: calls SecRandomCopyBytes as /dev/(u)random is sandboxed.
    /// - OpenBSD: uses the `getentropy(2)` system call.
    ///
    /// This does not block.
    pub struct OsRng {
        // dummy field to ensure that this struct cannot be constructed outside
        // of this module
        _dummy: (),
    }

    impl OsRng {
        /// Create a new `OsRng`.
        pub fn new() -> io::Result<OsRng> {
            Ok(OsRng { _dummy: () })
        }
    }

    impl Rng for OsRng {
        fn next_u32(&mut self) -> u32 {
            let mut v = [0; 4];
            self.fill_bytes(&mut v);
            unsafe { mem::transmute(v) }
        }
        fn next_u64(&mut self) -> u64 {
            let mut v = [0; 8];
            self.fill_bytes(&mut v);
            unsafe { mem::transmute(v) }
        }
        fn fill_bytes(&mut self, v: &mut [u8]) {
            // getentropy(2) permits a maximum buffer size of 256 bytes
            for s in v.chunks_mut(256) {
                let ret = unsafe {
                    libc::getentropy(s.as_mut_ptr() as *mut libc::c_void, s.len())
                };
                if ret == -1 {
                    panic!("unexpected getentropy error: {}", errno());
                }
            }
        }
    }
}

#[cfg(target_os = "ios")]
mod imp {
    use io;
    use mem;
    use ptr;
    use rand::Rng;
    use libc::{c_int, size_t};

    /// A random number generator that retrieves randomness straight from
    /// the operating system. Platform sources:
    ///
    /// - Unix-like systems (Linux, Android, Mac OSX): read directly from
    ///   `/dev/urandom`, or from `getrandom(2)` system call if available.
    /// - Windows: calls `CryptGenRandom`, using the default cryptographic
    ///   service provider with the `PROV_RSA_FULL` type.
    /// - iOS: calls SecRandomCopyBytes as /dev/(u)random is sandboxed.
    /// - OpenBSD: uses the `getentropy(2)` system call.
    ///
    /// This does not block.
    pub struct OsRng {
        // dummy field to ensure that this struct cannot be constructed outside
        // of this module
        _dummy: (),
    }

    enum SecRandom {}

    #[allow(non_upper_case_globals)]
    const kSecRandomDefault: *const SecRandom = ptr::null();

    #[link(name = "Security", kind = "framework")]
    extern "C" {
        fn SecRandomCopyBytes(rnd: *const SecRandom,
                              count: size_t, bytes: *mut u8) -> c_int;
    }

    impl OsRng {
        /// Create a new `OsRng`.
        pub fn new() -> io::Result<OsRng> {
            Ok(OsRng { _dummy: () })
        }
    }

    impl Rng for OsRng {
        fn next_u32(&mut self) -> u32 {
            let mut v = [0; 4];
            self.fill_bytes(&mut v);
            unsafe { mem::transmute(v) }
        }
        fn next_u64(&mut self) -> u64 {
            let mut v = [0; 8];
            self.fill_bytes(&mut v);
            unsafe { mem::transmute(v) }
        }
        fn fill_bytes(&mut self, v: &mut [u8]) {
            let ret = unsafe {
                SecRandomCopyBytes(kSecRandomDefault, v.len() as size_t,
                                   v.as_mut_ptr())
            };
            if ret == -1 {
                panic!("couldn't generate random bytes: {}",
                       io::Error::last_os_error());
            }
        }
    }
}

#[cfg(windows)]
mod imp {
    use io;
    use mem;
    use rand::Rng;
    use sys::c;

    /// A random number generator that retrieves randomness straight from
    /// the operating system. Platform sources:
    ///
    /// - Unix-like systems (Linux, Android, Mac OSX): read directly from
    ///   `/dev/urandom`, or from `getrandom(2)` system call if available.
    /// - Windows: calls `CryptGenRandom`, using the default cryptographic
    ///   service provider with the `PROV_RSA_FULL` type.
    /// - iOS: calls SecRandomCopyBytes as /dev/(u)random is sandboxed.
    /// - OpenBSD: uses the `getentropy(2)` system call.
    ///
    /// This does not block.
    pub struct OsRng {
        hcryptprov: c::HCRYPTPROV
    }

    impl OsRng {
        /// Create a new `OsRng`.
        pub fn new() -> io::Result<OsRng> {
            let mut hcp = 0;
            let ret = unsafe {
                c::CryptAcquireContextA(&mut hcp, 0 as c::LPCSTR, 0 as c::LPCSTR,
                                        c::PROV_RSA_FULL,
                                        c::CRYPT_VERIFYCONTEXT | c::CRYPT_SILENT)
            };

            if ret == 0 {
                Err(io::Error::last_os_error())
            } else {
                Ok(OsRng { hcryptprov: hcp })
            }
        }
    }

    impl Rng for OsRng {
        fn next_u32(&mut self) -> u32 {
            let mut v = [0; 4];
            self.fill_bytes(&mut v);
            unsafe { mem::transmute(v) }
        }
        fn next_u64(&mut self) -> u64 {
            let mut v = [0; 8];
            self.fill_bytes(&mut v);
            unsafe { mem::transmute(v) }
        }
        fn fill_bytes(&mut self, v: &mut [u8]) {
            let ret = unsafe {
                c::CryptGenRandom(self.hcryptprov, v.len() as c::DWORD,
                                  v.as_mut_ptr())
            };
            if ret == 0 {
                panic!("couldn't generate random bytes: {}",
                       io::Error::last_os_error());
            }
        }
    }

    impl Drop for OsRng {
        fn drop(&mut self) {
            let ret = unsafe {
                c::CryptReleaseContext(self.hcryptprov, 0)
            };
            if ret == 0 {
                panic!("couldn't release context: {}",
                       io::Error::last_os_error());
            }
        }
    }
}

#[cfg(test)]
mod tests {
    use sync::mpsc::channel;
    use rand::Rng;
    use super::OsRng;
    use thread;

    #[test]
    fn test_os_rng() {
        let mut r = OsRng::new().unwrap();

        r.next_u32();
        r.next_u64();

        let mut v = [0; 1000];
        r.fill_bytes(&mut v);
    }

    #[test]
    fn test_os_rng_tasks() {

        let mut txs = vec!();
        for _ in 0..20 {
            let (tx, rx) = channel();
            txs.push(tx);

            thread::spawn(move|| {
                // wait until all the threads are ready to go.
                rx.recv().unwrap();

                // deschedule to attempt to interleave things as much
                // as possible (XXX: is this a good test?)
                let mut r = OsRng::new().unwrap();
                thread::yield_now();
                let mut v = [0; 1000];

                for _ in 0..100 {
                    r.next_u32();
                    thread::yield_now();
                    r.next_u64();
                    thread::yield_now();
                    r.fill_bytes(&mut v);
                    thread::yield_now();
                }
            });
        }

        // start all the threads
        for tx in &txs {
            tx.send(()).unwrap();
        }
    }
}
<|endoftext|>


<commit_before>// Copyright 2013-2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

//! Interfaces to the operating system provided random number
//! generators.

pub use self::imp::OsRng;

#[cfg(unix)]
mod imp {
    use io::{IoResult, File};
    use path::Path;
    use rand::Rng;
    use rand::reader::ReaderRng;
    use result::{Ok, Err};

    /// A random number generator that retrieves randomness straight from
    /// the operating system. Platform sources:
    ///
    /// - Unix-like systems (Linux, Android, Mac OSX): read directly from
    ///   `/dev/urandom`.
    /// - Windows: calls `CryptGenRandom`, using the default cryptographic
    ///   service provider with the `PROV_RSA_FULL` type.
    ///
    /// This does not block.
    #[cfg(unix)]
    pub struct OsRng {
        inner: ReaderRng<File>
    }

    impl OsRng {
        /// Create a new `OsRng`.
        pub fn new() -> IoResult<OsRng> {
            let reader = try!(File::open(&Path::new("/dev/urandom")));
            let reader_rng = ReaderRng::new(reader);

            Ok(OsRng { inner: reader_rng })
        }
    }

    impl Rng for OsRng {
        fn next_u32(&mut self) -> u32 {
            self.inner.next_u32()
        }
        fn next_u64(&mut self) -> u64 {
            self.inner.next_u64()
        }
        fn fill_bytes(&mut self, v: &mut [u8]) {
            self.inner.fill_bytes(v)
        }
    }
}

#[cfg(windows)]
mod imp {
    extern crate libc;

    use core_collections::Collection;
    use io::{IoResult, IoError};
    use mem;
    use ops::Drop;
    use os;
    use rand::Rng;
    use result::{Ok, Err};
    use rt::stack;
    use self::libc::{c_ulong, DWORD, BYTE, LPCSTR, BOOL};
    use slice::MutableVector;

    type HCRYPTPROV = c_ulong;

    /// A random number generator that retrieves randomness straight from
    /// the operating system. Platform sources:
    ///
    /// - Unix-like systems (Linux, Android, Mac OSX): read directly from
    ///   `/dev/urandom`.
    /// - Windows: calls `CryptGenRandom`, using the default cryptographic
    ///   service provider with the `PROV_RSA_FULL` type.
    ///
    /// This does not block.
    pub struct OsRng {
        hcryptprov: HCRYPTPROV
    }

    static PROV_RSA_FULL: DWORD = 1;
    static CRYPT_SILENT: DWORD = 64;
    static CRYPT_VERIFYCONTEXT: DWORD = 0xF0000000;
    static NTE_BAD_SIGNATURE: DWORD = 0x80090006;

    #[allow(non_snake_case_functions)]
    extern "system" {
        fn CryptAcquireContextA(phProv: *mut HCRYPTPROV,
                                pszContainer: LPCSTR,
                                pszProvider: LPCSTR,
                                dwProvType: DWORD,
                                dwFlags: DWORD) -> BOOL;
        fn CryptGenRandom(hProv: HCRYPTPROV,
                          dwLen: DWORD,
                          pbBuffer: *mut BYTE) -> BOOL;
        fn CryptReleaseContext(hProv: HCRYPTPROV, dwFlags: DWORD) -> BOOL;
    }

    impl OsRng {
        /// Create a new `OsRng`.
        pub fn new() -> IoResult<OsRng> {
            let mut hcp = 0;
            let mut ret = unsafe {
                CryptAcquireContextA(&mut hcp, 0 as LPCSTR, 0 as LPCSTR,
                                     PROV_RSA_FULL,
                                     CRYPT_VERIFYCONTEXT | CRYPT_SILENT)
            };

            // FIXME #13259:
            // It turns out that if we can't acquire a context with the
            // NTE_BAD_SIGNATURE error code, the documentation states:
            //
            //     The provider DLL signature could not be verified. Either the
            //     DLL or the digital signature has been tampered with.
            //
            // Sounds fishy, no? As it turns out, our signature can be bad
            // because our Thread Information Block (TIB) isn't exactly what it
            // expects. As to why, I have no idea. The only data we store in the
            // TIB is the stack limit for each thread, but apparently that's
            // enough to make the signature valid.
            //
            // Furthermore, this error only happens the *first* time we call
            // CryptAcquireContext, so we don't have to worry about future
            // calls.
            //
            // Anyway, the fix employed here is that if we see this error, we
            // pray that we're not close to the end of the stack, temporarily
            // set the stack limit to 0 (what the TIB originally was), acquire a
            // context, and then reset the stack limit.
            //
            // Again, I'm not sure why this is the fix, nor why we're getting
            // this error. All I can say is that this seems to allow libnative
            // to progress where it otherwise would be hindered. Who knew?
            if ret == 0 && os::errno() as DWORD == NTE_BAD_SIGNATURE {
                unsafe {
                    let limit = stack::get_sp_limit();
                    stack::record_sp_limit(0);
                    ret = CryptAcquireContextA(&mut hcp, 0 as LPCSTR, 0 as LPCSTR,
                                               PROV_RSA_FULL,
                                               CRYPT_VERIFYCONTEXT | CRYPT_SILENT);
                    stack::record_sp_limit(limit);
                }
            }

            if ret == 0 {
                Err(IoError::last_error())
            } else {
                Ok(OsRng { hcryptprov: hcp })
            }
        }
    }

    impl Rng for OsRng {
        fn next_u32(&mut self) -> u32 {
            let mut v = [0u8, .. 4];
            self.fill_bytes(v);
            unsafe { mem::transmute(v) }
        }
        fn next_u64(&mut self) -> u64 {
            let mut v = [0u8, .. 8];
            self.fill_bytes(v);
            unsafe { mem::transmute(v) }
        }
        fn fill_bytes(&mut self, v: &mut [u8]) {
            let ret = unsafe {
                CryptGenRandom(self.hcryptprov, v.len() as DWORD,
                               v.as_mut_ptr())
            };
            if ret == 0 {
                fail!("couldn't generate random bytes: {}", os::last_os_error());
            }
        }
    }

    impl Drop for OsRng {
        fn drop(&mut self) {
            let ret = unsafe {
                CryptReleaseContext(self.hcryptprov, 0)
            };
            if ret == 0 {
                fail!("couldn't release context: {}", os::last_os_error());
            }
        }
    }
}

#[cfg(test)]
mod test {
    use prelude::*;

    use super::OsRng;
    use rand::Rng;
    use task;

    #[test]
    fn test_os_rng() {
        let mut r = OsRng::new().unwrap();

        r.next_u32();
        r.next_u64();

        let mut v = [0u8, .. 1000];
        r.fill_bytes(v);
    }

    #[test]
    fn test_os_rng_tasks() {

        let mut txs = vec!();
        for _ in range(0, 20) {
            let (tx, rx) = channel();
            txs.push(tx);
            task::spawn(proc() {
                // wait until all the tasks are ready to go.
                rx.recv();

                // deschedule to attempt to interleave things as much
                // as possible (XXX: is this a good test?)
                let mut r = OsRng::new().unwrap();
                task::deschedule();
                let mut v = [0u8, .. 1000];

                for _ in range(0, 100) {
                    r.next_u32();
                    task::deschedule();
                    r.next_u64();
                    task::deschedule();
                    r.fill_bytes(v);
                    task::deschedule();
                }
            })
        }

        // start all the tasks
        for tx in txs.iter() {
            tx.send(())
        }
    }
}
<commit_msg>auto merge of #14715 : vhbit/rust/ios-pr2, r=alexcrichton<commit_after>// Copyright 2013-2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

//! Interfaces to the operating system provided random number
//! generators.

pub use self::imp::OsRng;

#[cfg(unix, not(target_os = "ios"))]
mod imp {
    use io::{IoResult, File};
    use path::Path;
    use rand::Rng;
    use rand::reader::ReaderRng;
    use result::{Ok, Err};

    /// A random number generator that retrieves randomness straight from
    /// the operating system. Platform sources:
    ///
    /// - Unix-like systems (Linux, Android, Mac OSX): read directly from
    ///   `/dev/urandom`.
    /// - Windows: calls `CryptGenRandom`, using the default cryptographic
    ///   service provider with the `PROV_RSA_FULL` type.
    /// - iOS: calls SecRandomCopyBytes as /dev/(u)random is sandboxed
    /// This does not block.
    #[cfg(unix)]
    pub struct OsRng {
        inner: ReaderRng<File>
    }

    impl OsRng {
        /// Create a new `OsRng`.
        pub fn new() -> IoResult<OsRng> {
            let reader = try!(File::open(&Path::new("/dev/urandom")));
            let reader_rng = ReaderRng::new(reader);

            Ok(OsRng { inner: reader_rng })
        }
    }

    impl Rng for OsRng {
        fn next_u32(&mut self) -> u32 {
            self.inner.next_u32()
        }
        fn next_u64(&mut self) -> u64 {
            self.inner.next_u64()
        }
        fn fill_bytes(&mut self, v: &mut [u8]) {
            self.inner.fill_bytes(v)
        }
    }
}

#[cfg(target_os = "ios")]
mod imp {
    extern crate libc;

    use collections::Collection;
    use io::{IoResult};
    use kinds::marker;
    use mem;
    use os;
    use rand::Rng;
    use result::{Ok};
    use self::libc::{c_int, size_t};
    use slice::MutableVector;

    /// A random number generator that retrieves randomness straight from
    /// the operating system. Platform sources:
    ///
    /// - Unix-like systems (Linux, Android, Mac OSX): read directly from
    ///   `/dev/urandom`.
    /// - Windows: calls `CryptGenRandom`, using the default cryptographic
    ///   service provider with the `PROV_RSA_FULL` type.
    /// - iOS: calls SecRandomCopyBytes as /dev/(u)random is sandboxed
    /// This does not block.
    pub struct OsRng {
        marker: marker::NoCopy
    }

    struct SecRandom;

    static kSecRandomDefault: *SecRandom = 0 as *SecRandom;

    #[link(name = "Security", kind = "framework")]
    extern "C" {
        fn SecRandomCopyBytes(rnd: *SecRandom, count: size_t, bytes: *mut u8) -> c_int;
    }

    impl OsRng {
        /// Create a new `OsRng`.
        pub fn new() -> IoResult<OsRng> {
            Ok(OsRng {marker: marker::NoCopy} )
        }
    }

    impl Rng for OsRng {
        fn next_u32(&mut self) -> u32 {
            let mut v = [0u8, .. 4];
            self.fill_bytes(v);
            unsafe { mem::transmute(v) }
        }
        fn next_u64(&mut self) -> u64 {
            let mut v = [0u8, .. 8];
            self.fill_bytes(v);
            unsafe { mem::transmute(v) }
        }
        fn fill_bytes(&mut self, v: &mut [u8]) {
            let ret = unsafe {
                SecRandomCopyBytes(kSecRandomDefault, v.len() as size_t, v.as_mut_ptr())
            };
            if ret == -1 {
                fail!("couldn't generate random bytes: {}", os::last_os_error());
            }
        }
    }
}

#[cfg(windows)]
mod imp {
    extern crate libc;

    use core_collections::Collection;
    use io::{IoResult, IoError};
    use mem;
    use ops::Drop;
    use os;
    use rand::Rng;
    use result::{Ok, Err};
    use rt::stack;
    use self::libc::{c_ulong, DWORD, BYTE, LPCSTR, BOOL};
    use slice::MutableVector;

    type HCRYPTPROV = c_ulong;

    /// A random number generator that retrieves randomness straight from
    /// the operating system. Platform sources:
    ///
    /// - Unix-like systems (Linux, Android, Mac OSX): read directly from
    ///   `/dev/urandom`.
    /// - Windows: calls `CryptGenRandom`, using the default cryptographic
    ///   service provider with the `PROV_RSA_FULL` type.
    ///
    /// This does not block.
    pub struct OsRng {
        hcryptprov: HCRYPTPROV
    }

    static PROV_RSA_FULL: DWORD = 1;
    static CRYPT_SILENT: DWORD = 64;
    static CRYPT_VERIFYCONTEXT: DWORD = 0xF0000000;
    static NTE_BAD_SIGNATURE: DWORD = 0x80090006;

    #[allow(non_snake_case_functions)]
    extern "system" {
        fn CryptAcquireContextA(phProv: *mut HCRYPTPROV,
                                pszContainer: LPCSTR,
                                pszProvider: LPCSTR,
                                dwProvType: DWORD,
                                dwFlags: DWORD) -> BOOL;
        fn CryptGenRandom(hProv: HCRYPTPROV,
                          dwLen: DWORD,
                          pbBuffer: *mut BYTE) -> BOOL;
        fn CryptReleaseContext(hProv: HCRYPTPROV, dwFlags: DWORD) -> BOOL;
    }

    impl OsRng {
        /// Create a new `OsRng`.
        pub fn new() -> IoResult<OsRng> {
            let mut hcp = 0;
            let mut ret = unsafe {
                CryptAcquireContextA(&mut hcp, 0 as LPCSTR, 0 as LPCSTR,
                                     PROV_RSA_FULL,
                                     CRYPT_VERIFYCONTEXT | CRYPT_SILENT)
            };

            // FIXME #13259:
            // It turns out that if we can't acquire a context with the
            // NTE_BAD_SIGNATURE error code, the documentation states:
            //
            //     The provider DLL signature could not be verified. Either the
            //     DLL or the digital signature has been tampered with.
            //
            // Sounds fishy, no? As it turns out, our signature can be bad
            // because our Thread Information Block (TIB) isn't exactly what it
            // expects. As to why, I have no idea. The only data we store in the
            // TIB is the stack limit for each thread, but apparently that's
            // enough to make the signature valid.
            //
            // Furthermore, this error only happens the *first* time we call
            // CryptAcquireContext, so we don't have to worry about future
            // calls.
            //
            // Anyway, the fix employed here is that if we see this error, we
            // pray that we're not close to the end of the stack, temporarily
            // set the stack limit to 0 (what the TIB originally was), acquire a
            // context, and then reset the stack limit.
            //
            // Again, I'm not sure why this is the fix, nor why we're getting
            // this error. All I can say is that this seems to allow libnative
            // to progress where it otherwise would be hindered. Who knew?
            if ret == 0 && os::errno() as DWORD == NTE_BAD_SIGNATURE {
                unsafe {
                    let limit = stack::get_sp_limit();
                    stack::record_sp_limit(0);
                    ret = CryptAcquireContextA(&mut hcp, 0 as LPCSTR, 0 as LPCSTR,
                                               PROV_RSA_FULL,
                                               CRYPT_VERIFYCONTEXT | CRYPT_SILENT);
                    stack::record_sp_limit(limit);
                }
            }

            if ret == 0 {
                Err(IoError::last_error())
            } else {
                Ok(OsRng { hcryptprov: hcp })
            }
        }
    }

    impl Rng for OsRng {
        fn next_u32(&mut self) -> u32 {
            let mut v = [0u8, .. 4];
            self.fill_bytes(v);
            unsafe { mem::transmute(v) }
        }
        fn next_u64(&mut self) -> u64 {
            let mut v = [0u8, .. 8];
            self.fill_bytes(v);
            unsafe { mem::transmute(v) }
        }
        fn fill_bytes(&mut self, v: &mut [u8]) {
            let ret = unsafe {
                CryptGenRandom(self.hcryptprov, v.len() as DWORD,
                               v.as_mut_ptr())
            };
            if ret == 0 {
                fail!("couldn't generate random bytes: {}", os::last_os_error());
            }
        }
    }

    impl Drop for OsRng {
        fn drop(&mut self) {
            let ret = unsafe {
                CryptReleaseContext(self.hcryptprov, 0)
            };
            if ret == 0 {
                fail!("couldn't release context: {}", os::last_os_error());
            }
        }
    }
}

#[cfg(test)]
mod test {
    use prelude::*;

    use super::OsRng;
    use rand::Rng;
    use task;

    #[test]
    fn test_os_rng() {
        let mut r = OsRng::new().unwrap();

        r.next_u32();
        r.next_u64();

        let mut v = [0u8, .. 1000];
        r.fill_bytes(v);
    }

    #[test]
    fn test_os_rng_tasks() {

        let mut txs = vec!();
        for _ in range(0, 20) {
            let (tx, rx) = channel();
            txs.push(tx);
            task::spawn(proc() {
                // wait until all the tasks are ready to go.
                rx.recv();

                // deschedule to attempt to interleave things as much
                // as possible (XXX: is this a good test?)
                let mut r = OsRng::new().unwrap();
                task::deschedule();
                let mut v = [0u8, .. 1000];

                for _ in range(0, 100) {
                    r.next_u32();
                    task::deschedule();
                    r.next_u64();
                    task::deschedule();
                    r.fill_bytes(v);
                    task::deschedule();
                }
            })
        }

        // start all the tasks
        for tx in txs.iter() {
            tx.send(())
        }
    }
}
<|endoftext|>


<commit_before>#[cfg(target_family="unix")]
extern crate cursive;

#[cfg(target_family="unix")]
use cursive::Cursive;
#[cfg(target_family="unix")]
use cursive::traits::*;
#[cfg(target_family="unix")]
use cursive::views::{Dialog, DummyView, LinearLayout, SelectView, TextView};

#[cfg(target_family="unix")]
use std::fs::{self, DirEntry, File};
#[cfg(target_family="unix")]
use std::io::Read;
#[cfg(target_family="unix")]
use std::path::Path;

#[cfg(target_family="windows")]
fn main() {
    println!("TODO");
}

#[cfg(target_family="unix")]
fn file_picker<D>(directory: D) -> SelectView<DirEntry>
    where D: AsRef<Path>
{
    let mut view = SelectView::new();
    for entry in fs::read_dir(directory).expect("can't read directory") {
        if let Ok(e) = entry {
            let file_name = e.file_name().into_string().unwrap();
            view.add_item(file_name, e);
        }
    }
    view.on_select(update_status).on_submit(load_contents)
}

#[cfg(target_family="unix")]
fn update_status(app: &mut Cursive, entry: &DirEntry) {
    let status_bar = app.find_id::<TextView>("status").unwrap();
    let file_name = entry.file_name().into_string().unwrap();
    let file_size = entry.metadata().unwrap().len();
    let content = format!("{}: {} bytes", file_name, file_size);
    status_bar.set_content(content);
}

#[cfg(target_family="unix")]
fn load_contents(app: &mut Cursive, entry: &DirEntry) {
    let text_view = app.find_id::<TextView>("contents").unwrap();
    let content = if entry.metadata().unwrap().is_dir() {
        "<DIR>".to_string()
    } else {
        let mut buf = String::new();
        let _ = File::open(entry.file_name())
            .and_then(|mut f| f.read_to_string(&mut buf))
            .map_err(|e| buf = format!("Error: {}", e));
        buf
    };
    text_view.set_content(content);
}

#[cfg(target_family="unix")]
fn main() {
    println!("24 Days of Rust vol. 2 - cursive");
    let mut app = Cursive::new();
    let mut panes = LinearLayout::horizontal();
    let picker = file_picker(".");
    panes.add_child(picker.fixed_size((30, 25)));
    panes.add_child(DummyView);
    panes.add_child(TextView::new("file contents")
        .with_id("contents")
        .fixed_size((50, 25)));
    let mut layout = LinearLayout::vertical();
    layout.add_child(panes);
    layout.add_child(TextView::new("status")
        .scrollable(false)
        .with_id("status")
        .fixed_size((80, 1)));
    app.add_layer(Dialog::around(layout).button("Quit", |a| a.quit()));
    app.run();
}
<commit_msg>Fix cursive example.<commit_after>#[cfg(target_family="unix")]
extern crate cursive;

#[cfg(target_family="unix")]
use cursive::Cursive;
#[cfg(target_family="unix")]
use cursive::traits::*;
#[cfg(target_family="unix")]
use cursive::views::{Dialog, DummyView, LinearLayout, SelectView, TextView};

#[cfg(target_family="unix")]
use std::fs::{self, DirEntry, File};
#[cfg(target_family="unix")]
use std::io::Read;
#[cfg(target_family="unix")]
use std::path::Path;

#[cfg(target_family="windows")]
fn main() {
    println!("TODO");
}

#[cfg(target_family="unix")]
fn file_picker<D>(directory: D) -> SelectView<DirEntry>
    where D: AsRef<Path>
{
    let mut view = SelectView::new();
    for entry in fs::read_dir(directory).expect("can't read directory") {
        if let Ok(e) = entry {
            let file_name = e.file_name().into_string().unwrap();
            view.add_item(file_name, e);
        }
    }
    view.on_select(update_status).on_submit(load_contents)
}

#[cfg(target_family="unix")]
fn update_status(app: &mut Cursive, entry: &DirEntry) {
    let mut status_bar = app.find_id::<TextView>("status").unwrap();
    let file_name = entry.file_name().into_string().unwrap();
    let file_size = entry.metadata().unwrap().len();
    let content = format!("{}: {} bytes", file_name, file_size);
    status_bar.set_content(content);
}

#[cfg(target_family="unix")]
fn load_contents(app: &mut Cursive, entry: &DirEntry) {
    let mut text_view = app.find_id::<TextView>("contents").unwrap();
    let content = if entry.metadata().unwrap().is_dir() {
        "<DIR>".to_string()
    } else {
        let mut buf = String::new();
        let _ = File::open(entry.file_name())
            .and_then(|mut f| f.read_to_string(&mut buf))
            .map_err(|e| buf = format!("Error: {}", e));
        buf
    };
    text_view.set_content(content);
}

#[cfg(target_family="unix")]
fn main() {
    println!("24 Days of Rust vol. 2 - cursive");
    let mut app = Cursive::new();
    let mut panes = LinearLayout::horizontal();
    let picker = file_picker(".");
    panes.add_child(picker.fixed_size((30, 25)));
    panes.add_child(DummyView);
    panes.add_child(TextView::new("file contents")
        .with_id("contents")
        .fixed_size((50, 25)));
    let mut layout = LinearLayout::vertical();
    layout.add_child(panes);
    layout.add_child(TextView::new("status")
        .scrollable(false)
        .with_id("status")
        .fixed_size((80, 1)));
    app.add_layer(Dialog::around(layout).button("Quit", |a| a.quit()));
    app.run();
}
<|endoftext|>