advapi32: Implement GetSecurityInfo. [take 3]

[Dan Hipschman]

The patch is the same as the last one except I set the out args to NULL
before calling the GetSecurityDescriptorFoo functions, since these only
touch the pointers if the fields exist, whereas GetSecurityInfo should
set them to NULL if they don't.  I also took out the assert, due to
getting no support for it on the list.

---
 dlls/advapi32/security.c       |   62 ++++++++++++++++++++++++++++++++++++++-
 dlls/advapi32/tests/security.c |   32 ++++++++++++++++++++
 2 files changed, 92 insertions(+), 2 deletions(-)

diff --git a/dlls/advapi32/security.c b/dlls/advapi32/security.c
index 95b7a7b..6a19ef0 100644
--- a/dlls/advapi32/security.c
+++ b/dlls/advapi32/security.c
@@ -2710,6 +2710,22 @@ BOOL WINAPI PrivilegedServiceAuditAlarmW( LPCWSTR SubsystemName, LPCWSTR Service
 
 /******************************************************************************
  * GetSecurityInfo [ADVAPI32.@]
+ *
+ * Retrieves a copy of the security descriptor associated with an object.
+ *
+ * PARAMS
+ *  hObject              [I] A handle for the object.
+ *  ObjectType           [I] The type of object.
+ *  SecurityInfo         [I] A bitmask indicating what info to retrieve.
+ *  ppsidOwner           [O] If non-null, receives a pointer to the owner SID.
+ *  ppsidGroup           [O] If non-null, receives a pointer to the group SID.
+ *  ppDacl               [O] If non-null, receives a pointer to the DACL.
+ *  ppSacl               [O] If non-null, receives a pointer to the SACL.
+ *  ppSecurityDescriptor [O] Receives a pointer to the security descriptor,
+ *                           which must be freed with LocalFree.
+ *
+ * RETURNS
+ *  ERROR_SUCCESS if all's well, and a WIN32 error code otherwise.
  */
 DWORD WINAPI GetSecurityInfo(
     HANDLE hObject, SE_OBJECT_TYPE ObjectType,
@@ -2718,8 +2734,50 @@ DWORD WINAPI GetSecurityInfo(
     PSECURITY_DESCRIPTOR *ppSecurityDescriptor
 )
 {
-  FIXME("stub!\n");
-  return ERROR_BAD_PROVIDER;
+    PSECURITY_DESCRIPTOR sd;
+    NTSTATUS status;
+    ULONG n1, n2;
+    BOOL present, defaulted;
+
+    status = NtQuerySecurityObject(hObject, SecurityInfo, NULL, 0, &n1);
+    if (status != STATUS_BUFFER_TOO_SMALL && status != STATUS_SUCCESS)
+        return RtlNtStatusToDosError(status);
+
+    sd = LocalAlloc(0, n1);
+    if (!sd)
+        return ERROR_NOT_ENOUGH_MEMORY;
+
+    status = NtQuerySecurityObject(hObject, SecurityInfo, sd, n1, &n2);
+    if (status != STATUS_SUCCESS)
+    {
+        LocalFree(sd);
+        return RtlNtStatusToDosError(status);
+    }
+
+    if (ppsidOwner)
+    {
+        *ppsidOwner = NULL;
+        GetSecurityDescriptorOwner(sd, ppsidOwner, &defaulted);
+    }
+    if (ppsidGroup)
+    {
+        *ppsidGroup = NULL;
+        GetSecurityDescriptorGroup(sd, ppsidGroup, &defaulted);
+    }
+    if (ppDacl)
+    {
+        *ppDacl = NULL;
+        GetSecurityDescriptorDacl(sd, &present, ppDacl, &defaulted);
+    }
+    if (ppSacl)
+    {
+        *ppSacl = NULL;
+        GetSecurityDescriptorSacl(sd, &present, ppSacl, &defaulted);
+    }
+    if (ppSecurityDescriptor)
+        *ppSecurityDescriptor = sd;
+
+    return ERROR_SUCCESS;
 }
 
 /******************************************************************************
diff --git a/dlls/advapi32/tests/security.c b/dlls/advapi32/tests/security.c
index ea4d912..9eab933 100644
--- a/dlls/advapi32/tests/security.c
+++ b/dlls/advapi32/tests/security.c
@@ -2483,6 +2483,37 @@ static void test_acls(void)
     ok(!ret && GetLastError() == ERROR_INVALID_PARAMETER, "InitializeAcl(-1) failed with error %d\n", GetLastError());
 }
 
+static void test_GetSecurityInfo(void)
+{
+    HANDLE obj;
+    PSECURITY_DESCRIPTOR sd;
+    PSID owner, group;
+    PACL dacl;
+    DWORD ret;
+
+    /* Create something.  Files have lots of associated security info.  */
+    obj = CreateFile(myARGV[0], GENERIC_READ, FILE_SHARE_READ, NULL,
+                     OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
+    if (!obj)
+    {
+        skip("Couldn't create an object for GetSecurityInfo test\n");
+        return;
+    }
+
+    ret = GetSecurityInfo(obj, SE_FILE_OBJECT,
+                          OWNER_SECURITY_INFORMATION | GROUP_SECURITY_INFORMATION | DACL_SECURITY_INFORMATION,
+                          &owner, &group, &dacl, NULL, &sd);
+    ok(ret == ERROR_SUCCESS, "GetSecurityInfo returned %d\n", ret);
+    ok(sd != NULL, "GetSecurityInfo\n");
+    ok(owner != NULL, "GetSecurityInfo\n");
+    ok(group != NULL, "GetSecurityInfo\n");
+    ok(dacl != NULL, "GetSecurityInfo\n");
+    ok(IsValidAcl(dacl), "GetSecurityInfo\n");
+
+    LocalFree(sd);
+    CloseHandle(obj);
+}
+
 START_TEST(security)
 {
     init();
@@ -2511,4 +2542,5 @@ START_TEST(security)
     test_ConvertSecurityDescriptorToString();
     test_PrivateObjectSecurity();
     test_acls();
+    test_GetSecurityInfo();
 }