-
Notifications
You must be signed in to change notification settings - Fork 12.5k
/
os.rs
315 lines (279 loc) · 9.86 KB
/
os.rs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
// 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: *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 {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(0u, 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(0u, 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(())
}
}
}