xref: /aosp_15_r20/external/cronet/third_party/boringssl/src/crypto/rand_extra/windows.c (revision 6777b5387eb2ff775bb5750e3f5d96f37fb7352b)
1 /* Copyright (c) 2014, Google Inc.
2  *
3  * Permission to use, copy, modify, and/or distribute this software for any
4  * purpose with or without fee is hereby granted, provided that the above
5  * copyright notice and this permission notice appear in all copies.
6  *
7  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
8  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
10  * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
12  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
13  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
14 
15 #include <openssl/rand.h>
16 
17 #include "../fipsmodule/rand/internal.h"
18 
19 #if defined(OPENSSL_RAND_WINDOWS)
20 
21 #include <limits.h>
22 #include <stdlib.h>
23 
24 OPENSSL_MSVC_PRAGMA(warning(push, 3))
25 
26 #include <windows.h>
27 
28 #if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP) && \
29     !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
30 #include <bcrypt.h>
31 OPENSSL_MSVC_PRAGMA(comment(lib, "bcrypt.lib"))
32 #endif  // WINAPI_PARTITION_APP && !WINAPI_PARTITION_DESKTOP
33 
OPENSSL_MSVC_PRAGMA(warning (pop))34 OPENSSL_MSVC_PRAGMA(warning(pop))
35 
36 #if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP) && \
37     !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
38 
39 void CRYPTO_init_sysrand(void) {}
40 
CRYPTO_sysrand(uint8_t * out,size_t requested)41 void CRYPTO_sysrand(uint8_t *out, size_t requested) {
42   while (requested > 0) {
43     ULONG output_bytes_this_pass = ULONG_MAX;
44     if (requested < output_bytes_this_pass) {
45       output_bytes_this_pass = (ULONG)requested;
46     }
47     if (!BCRYPT_SUCCESS(BCryptGenRandom(
48             /*hAlgorithm=*/NULL, out, output_bytes_this_pass,
49             BCRYPT_USE_SYSTEM_PREFERRED_RNG))) {
50       abort();
51     }
52     requested -= output_bytes_this_pass;
53     out += output_bytes_this_pass;
54   }
55 }
56 
57 #else
58 
59 // See: https://learn.microsoft.com/en-us/windows/win32/seccng/processprng
60 typedef BOOL (WINAPI *ProcessPrngFunction)(PBYTE pbData, SIZE_T cbData);
61 static ProcessPrngFunction g_processprng_fn = NULL;
62 
63 static void init_processprng(void) {
64   HMODULE hmod = LoadLibraryW(L"bcryptprimitives");
65   if (hmod == NULL) {
66     abort();
67   }
68   g_processprng_fn = (ProcessPrngFunction)GetProcAddress(hmod, "ProcessPrng");
69   if (g_processprng_fn == NULL) {
70     abort();
71   }
72 }
73 
74 void CRYPTO_init_sysrand(void) {
75   static CRYPTO_once_t once = CRYPTO_ONCE_INIT;
76   CRYPTO_once(&once, init_processprng);
77 }
78 
79 void CRYPTO_sysrand(uint8_t *out, size_t requested) {
80   CRYPTO_init_sysrand();
81   // On non-UWP configurations, use ProcessPrng instead of BCryptGenRandom
82   // to avoid accessing resources that may be unavailable inside the
83   // Chromium sandbox. See https://crbug.com/74242
84   if (!g_processprng_fn(out, requested)) {
85     abort();
86   }
87 }
88 
89 #endif  // WINAPI_PARTITION_APP && !WINAPI_PARTITION_DESKTOP
90 
CRYPTO_sysrand_for_seed(uint8_t * out,size_t requested)91 void CRYPTO_sysrand_for_seed(uint8_t *out, size_t requested) {
92   CRYPTO_sysrand(out, requested);
93 }
94 
95 #endif  // OPENSSL_RAND_WINDOWS
96