From aedbf1640ced8fc09dc980ead2a387a59d8f7f68 Mon Sep 17 00:00:00 2001
From: Steve Lhomme <robux4@ycbcr.xyz>
Date: Tue, 3 Apr 2018 11:44:25 +0200
Subject: [PATCH] avutil/random_seed: use bcrypt instead of the old wincrypt
 API

Remove the wincrypt API calls since we don't support XP anymore and bcrypt is
available since Vista, even on Windows Store builds.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: James Almer <jamrial@gmail.com>
---
 configure               |  6 +++---
 libavutil/random_seed.c | 19 ++++++++++---------
 2 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/configure b/configure
index 73857f4511..36e425be62 100755
--- a/configure
+++ b/configure
@@ -2142,10 +2142,10 @@ SYSTEM_FUNCS="
 "
 
 SYSTEM_LIBRARIES="
+    bcrypt
     vaapi_drm
     vaapi_x11
     vdpau_x11
-    wincrypt
 "
 
 TOOLCHAIN_FEATURES="
@@ -3445,7 +3445,7 @@ avformat_deps="avcodec avutil"
 avformat_suggest="libm network zlib"
 avresample_deps="avutil"
 avresample_suggest="libm"
-avutil_suggest="clock_gettime ffnvcodec libm libdrm libmfx opencl user32 vaapi videotoolbox corefoundation corevideo coremedia wincrypt"
+avutil_suggest="clock_gettime ffnvcodec libm libdrm libmfx opencl user32 vaapi videotoolbox corefoundation corevideo coremedia bcrypt"
 postproc_deps="avutil gpl"
 postproc_suggest="libm"
 swresample_deps="avutil"
@@ -5828,9 +5828,9 @@ check_header asm/types.h
 check_builtin stdatomic stdatomic.h "atomic_int foo, bar = ATOMIC_VAR_INIT(-1); atomic_store(&foo, 0); foo += bar"
 
 check_lib advapi32 "windows.h"            RegCloseKey          -ladvapi32
+check_lib bcrypt   "windows.h bcrypt.h"   BCryptGenRandom      -lbcrypt
 check_lib ole32    "windows.h"            CoTaskMemFree        -lole32
 check_lib shell32  "windows.h shellapi.h" CommandLineToArgvW   -lshell32
-check_lib wincrypt "windows.h wincrypt.h" CryptGenRandom       -ladvapi32
 check_lib psapi    "windows.h psapi.h"    GetProcessMemoryInfo -lpsapi
 
 check_lib android android/native_window.h ANativeWindow_acquire -landroid
diff --git a/libavutil/random_seed.c b/libavutil/random_seed.c
index 881c23c8c8..70dc509d2f 100644
--- a/libavutil/random_seed.c
+++ b/libavutil/random_seed.c
@@ -26,9 +26,9 @@
 #if HAVE_IO_H
 #include <io.h>
 #endif
-#if HAVE_WINCRYPT
+#if HAVE_BCRYPT
 #include <windows.h>
-#include <wincrypt.h>
+#include <bcrypt.h>
 #endif
 #include <fcntl.h>
 #include <math.h>
@@ -121,13 +121,14 @@ uint32_t av_get_random_seed(void)
 {
     uint32_t seed;
 
-#if HAVE_WINCRYPT
-    HCRYPTPROV provider;
-    if (CryptAcquireContext(&provider, NULL, NULL, PROV_RSA_FULL,
-                            CRYPT_VERIFYCONTEXT | CRYPT_SILENT)) {
-        BOOL ret = CryptGenRandom(provider, sizeof(seed), (PBYTE) &seed);
-        CryptReleaseContext(provider, 0);
-        if (ret)
+#if HAVE_BCRYPT
+    BCRYPT_ALG_HANDLE algo_handle;
+    NTSTATUS ret = BCryptOpenAlgorithmProvider(&algo_handle, BCRYPT_RNG_ALGORITHM,
+                                               MS_PRIMITIVE_PROVIDER, 0);
+    if (BCRYPT_SUCCESS(ret)) {
+        NTSTATUS ret = BCryptGenRandom(algo_handle, (UCHAR*)&seed, sizeof(seed), 0);
+        BCryptCloseAlgorithmProvider(algo_handle, 0);
+        if (BCRYPT_SUCCESS(ret))
             return seed;
     }
 #endif