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
|
/*
* Copyright © 2021 Michael Smith <mikesmiffy128@gmail.com>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
* OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
#include <stdbool.h>
#include "intdefs.h"
#include "os.h"
#ifdef _WIN32
// SystemFunction036 is the *real* name of "RtlGenRandom," and is also
// incorrectly defined in system headers. Yay, Windows.
int __stdcall SystemFunction036(void *buf, ulong sz);
#endif
bool os_mprot(void *addr, int len, int fl) {
#ifdef _WIN32
ulong old;
return !!VirtualProtect(addr, len, fl, &old);
#else
// round down address and round up size
addr = (void *)((ulong)addr & ~(4095));
len = len + 4095 & ~(4095);
return mprotect(addr, len, fl) != -1;
#endif
}
#ifdef _WIN32
void *os_dlsym(void *m, const char *s) {
return (void *)GetProcAddress(m, s);
}
#endif
void os_randombytes(void *buf, int sz) {
// if these calls ever fail, the system is fundamentally broken with no
// recourse, so just loop until success. hopefully nothing will go wrong.
#ifdef _WIN32
while (!SystemFunction036(buf, sz));
#else
while (getentropy(buf, sz) == -1);
#endif
}
// vi: sw=4 ts=4 noet tw=80 cc=80
|
