rust/src/rt/rust_rng.cpp
Huon Wilson 0951313c1e Remove the C(++) ISAAC Rng from the old rt.
This has to leave rust_gen_seed and rng_gen_seed around since they're
used to initialise the std::rand RNGs.
2013-09-23 00:11:43 +10:00

84 lines
2.5 KiB
C++

// Copyright 2012 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.
#include "rust_globals.h"
#include "rust_rng.h"
#include "rust_util.h"
#ifdef __WIN32__
void
win32_require(LPCTSTR fn, BOOL ok) {
if (!ok) {
LPTSTR buf;
DWORD err = GetLastError();
FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS,
NULL, err,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
(LPTSTR) &buf, 0, NULL );
fprintf(stderr, "%s failed with error %ld: %s", fn, err, buf);
LocalFree((HLOCAL)buf);
abort();
}
}
#endif
void
rng_gen_seed(uint8_t* dest, size_t size) {
#ifdef __WIN32__
HCRYPTPROV hProv;
win32_require
(_T("CryptAcquireContext"),
CryptAcquireContext(&hProv, NULL, NULL, PROV_RSA_FULL,
CRYPT_VERIFYCONTEXT|CRYPT_SILENT));
win32_require
(_T("CryptGenRandom"), CryptGenRandom(hProv, size, (BYTE*) dest));
win32_require
(_T("CryptReleaseContext"), CryptReleaseContext(hProv, 0));
#else
int fd = open("/dev/urandom", O_RDONLY);
if (fd == -1) {
fprintf(stderr, "error opening /dev/urandom: %s", strerror(errno));
abort();
}
size_t amount = 0;
do {
ssize_t ret = read(fd, dest+amount, size-amount);
if (ret < 0) {
fprintf(stderr, "error reading /dev/urandom: %s", strerror(errno));
abort();
}
else if (ret == 0) {
fprintf(stderr, "somehow hit eof reading from /dev/urandom");
abort();
}
amount += (size_t)ret;
} while (amount < size);
int ret = close(fd);
if (ret != 0) {
fprintf(stderr, "error closing /dev/urandom: %s", strerror(errno));
// FIXME #3697: Why does this fail sometimes?
// abort();
}
#endif
}
//
// Local Variables:
// mode: C++
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// End:
//