From 74f2e090cfd9f9f1fab8d5ef820525b8f7aa6033 Mon Sep 17 00:00:00 2001
From: Juan Lang <juan.lang@gmail.com>
Date: Mon, 14 Jan 2008 11:15:35 -0800
Subject: [PATCH] Fix race condition in loading default provider
---
 dlls/crypt32/main.c |   12 ++++++++++--
 1 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/dlls/crypt32/main.c b/dlls/crypt32/main.c
index fa90ee0..922dd19 100644
--- a/dlls/crypt32/main.c
+++ b/dlls/crypt32/main.c
@@ -59,8 +59,16 @@ BOOL WINAPI DllMain(HINSTANCE hInstance,
 HCRYPTPROV CRYPT_GetDefaultProvider(void)
 {
     if (!hDefProv)
-        CryptAcquireContextW(&hDefProv, NULL, MS_ENHANCED_PROV_W,
-         PROV_RSA_FULL, CRYPT_VERIFYCONTEXT);
+    {
+        HCRYPTPROV prov;
+
+        CryptAcquireContextW(&prov, NULL, MS_ENHANCED_PROV_W, PROV_RSA_FULL,
+         CRYPT_VERIFYCONTEXT);
+        InterlockedCompareExchangePointer((PVOID *)&hDefProv, (PVOID)prov,
+         NULL);
+        if (hDefProv != prov)
+            CryptReleaseContext(prov, 0);
+    }
     return hDefProv;
 }
 
-- 
1.4.1