1 files changed, 228 insertions, 0 deletions
diff --git a/src/VBox/Runtime/generic/memsafer-generic.cpp b/src/VBox/Runtime/generic/memsafer-generic.cpp
new file mode 100644
index 00000000..03bf9357
--- /dev/null
+++ b/src/VBox/Runtime/generic/memsafer-generic.cpp
@@ -0,0 +1,228 @@
+/* $Id: memsafer-generic.cpp $ */
+/** @file
+ * IPRT - Memory Allocate for Sensitive Data, generic heap-based implementation.
+ */
+
+/*
+ * Copyright (C) 2006-2020 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
+ * VirtualBox OSE distribution, in which case the provisions of the
+ * CDDL are applicable instead of those of the GPL.
+ *
+ * You may elect to license modified versions of this file under the
+ * terms and conditions of either the GPL or the CDDL or both.
+ */
+
+
+/*********************************************************************************************************************************
+*   Header Files                                                                                                                 *
+*********************************************************************************************************************************/
+#include "internal/iprt.h"
+#include <iprt/memsafer.h>
+
+#include <iprt/assert.h>
+#include <iprt/err.h>
+#include <iprt/string.h>
+
+
+/*********************************************************************************************************************************
+*   Defined Constants And Macros                                                                                                 *
+*********************************************************************************************************************************/
+/** Allocation size alignment. */
+#define RTMEMSAFER_ALIGN        16
+/** Padding after the block to avoid small overruns. */
+#define RTMEMSAFER_PAD_BEFORE   96
+/** Padding after the block to avoid small underruns. */
+#define RTMEMSAFER_PAD_AFTER    32
+
+
+/*********************************************************************************************************************************
+*   Global Variables                                                                                                             *
+*********************************************************************************************************************************/
+/** XOR scrabler value.
+ * @todo determine this at runtime */
+#if ARCH_BITS == 32
+static uintptr_t g_uScramblerXor = UINT32_C(0x867af88d);
+#elif ARCH_BITS == 64
+static uintptr_t g_uScramblerXor = UINT64_C(0xed95ecc99416d312);
+#else
+# error "Bad ARCH_BITS value"
+#endif
+
+
+
+RTDECL(int) RTMemSaferScramble(void *pv, size_t cb)
+{
+
+    AssertMsg(*(size_t *)((char *)pv - RTMEMSAFER_PAD_BEFORE) == cb,
+              ("*pvStart=%#zx cb=%#zx\n", *(size_t *)((char *)pv- RTMEMSAFER_PAD_BEFORE), cb));
+
+    /* Note! This isn't supposed to be safe, just less obvious. */
+    uintptr_t *pu = (uintptr_t *)pv;
+    cb = RT_ALIGN_Z(cb, RTMEMSAFER_ALIGN);
+    while (cb > 0)
+    {
+        *pu ^= g_uScramblerXor;
+        pu++;
+        cb -= sizeof(*pu);
+    }
+
+    return VINF_SUCCESS;
+}
+RT_EXPORT_SYMBOL(RTMemSaferScramble);
+
+
+RTDECL(int) RTMemSaferUnscramble(void *pv, size_t cb)
+{
+    AssertMsg(*(size_t *)((char *)pv - RTMEMSAFER_PAD_BEFORE) == cb,
+              ("*pvStart=%#zx cb=%#zx\n", *(size_t *)((char *)pv - RTMEMSAFER_PAD_BEFORE), cb));
+
+    /* Note! This isn't supposed to be safe, just less obvious. */
+    uintptr_t *pu = (uintptr_t *)pv;
+    cb = RT_ALIGN_Z(cb, RTMEMSAFER_ALIGN);
+    while (cb > 0)
+    {
+        *pu ^= g_uScramblerXor;
+        pu++;
+        cb -= sizeof(*pu);
+    }
+
+    return VINF_SUCCESS;
+}
+RT_EXPORT_SYMBOL(RTMemSaferUnscramble);
+
+
+RTDECL(int) RTMemSaferAllocZExTag(void **ppvNew, size_t cb, uint32_t fFlags, const char *pszTag) RT_NO_THROW_DEF
+{
+    AssertPtrReturn(ppvNew, VERR_INVALID_PARAMETER);
+    *ppvNew = NULL;
+    AssertReturn(cb, VERR_INVALID_PARAMETER);
+    RT_NOREF_PV(pszTag);
+
+    /*
+     * We support none of the hard requirements passed thru flags.
+     */
+    if (fFlags == 0)
+    {
+        /*
+         * Don't request zeroed memory.  We want random heap garbage in the
+         * padding zones, nothing that makes our allocations easier to find.
+         */
+        size_t cbUser = RT_ALIGN_Z(cb, RTMEMSAFER_ALIGN);
+        void *pvNew = RTMemAlloc(cbUser + RTMEMSAFER_PAD_BEFORE + RTMEMSAFER_PAD_AFTER);
+        if (pvNew)
+        {
+#ifdef RT_STRICT /* For checking input in string builds. */
+            memset(pvNew, 0xad, RTMEMSAFER_PAD_BEFORE);
+            memset((char *)pvNew + RTMEMSAFER_PAD_BEFORE + cb, 0xda, RTMEMSAFER_PAD_AFTER + (cbUser - cb));
+            *(size_t *)pvNew = cb;
+#endif
+
+            void *pvUser = (char *)pvNew + RTMEMSAFER_PAD_BEFORE;
+            *ppvNew = pvUser;
+
+            /* You don't use this API for performance, so we always clean memory. */
+            RT_BZERO(pvUser, cb);
+
+            return VINF_SUCCESS;
+        }
+        return VERR_NO_MEMORY;
+    }
+    AssertReturn(!(fFlags & ~RTMEMSAFER_F_VALID_MASK), VERR_INVALID_FLAGS);
+    return VWRN_UNABLE_TO_SATISFY_REQUIREMENTS;
+}
+RT_EXPORT_SYMBOL(RTMemSaferAllocZExTag);
+
+
+RTDECL(void) RTMemSaferFree(void *pv, size_t cb) RT_NO_THROW_DEF
+{
+    if (pv)
+    {
+        Assert(cb); /* does not support openssl. */
+        void *pvStart = (char *)pv - RTMEMSAFER_PAD_BEFORE;
+        AssertMsg(*(size_t *)pvStart == cb, ("*pvStart=%#zx cb=%#zx\n", *(size_t *)pvStart, cb));
+        RTMemWipeThoroughly(pv, RT_ALIGN_Z(cb, RTMEMSAFER_ALIGN), 3);
+        RTMemFree(pvStart);
+    }
+    else
+        Assert(cb == 0);
+}
+RT_EXPORT_SYMBOL(RTMemSaferFree);
+
+
+RTDECL(int) RTMemSaferReallocZExTag(size_t cbOld, void *pvOld, size_t cbNew, void **ppvNew, uint32_t fFlags, const char *pszTag) RT_NO_THROW_DEF
+{
+    /*
+     * We cannot let the heap move us around because we will be failing in our
+     * duty to clean things up.  So, allocate a new block, copy over the old
+     * content, and free the old one.
+     */
+    int rc;
+    /* Real realloc. */
+    if (cbNew && cbOld)
+    {
+        AssertPtr(pvOld);
+        AssertMsg(*(size_t *)((char *)pvOld - RTMEMSAFER_PAD_BEFORE) == cbOld,
+                  ("*pvStart=%#zx cbOld=%#zx\n", *(size_t *)((char *)pvOld - RTMEMSAFER_PAD_BEFORE), cbOld));
+
+        /*
+         * We support none of the hard requirements passed thru flags.
+         */
+        void *pvNew;
+        rc = RTMemSaferAllocZExTag(&pvNew, cbNew, fFlags, pszTag);
+        if (RT_SUCCESS(rc))
+        {
+            memcpy(pvNew, pvOld, RT_MIN(cbNew, cbOld));
+            RTMemSaferFree(pvOld, cbOld);
+            *ppvNew = pvNew;
+        }
+    }
+    /* First allocation. */
+    else if (!cbOld)
+    {
+        Assert(pvOld == NULL);
+        rc = RTMemSaferAllocZExTag(ppvNew, cbNew, fFlags, pszTag);
+    }
+    /* Free operation*/
+    else
+    {
+        RTMemSaferFree(pvOld, cbOld);
+        rc = VINF_SUCCESS;
+    }
+    return rc;
+}
+RT_EXPORT_SYMBOL(RTMemSaferReallocZExTag);
+
+
+RTDECL(void *) RTMemSaferAllocZTag(size_t cb, const char *pszTag) RT_NO_THROW_DEF
+{
+    void *pvNew = NULL;
+    int rc = RTMemSaferAllocZExTag(&pvNew, cb, 0 /*fFlags*/, pszTag);
+    if (RT_SUCCESS(rc))
+        return pvNew;
+    return NULL;
+}
+RT_EXPORT_SYMBOL(RTMemSaferAllocZTag);
+
+
+RTDECL(void *) RTMemSaferReallocZTag(size_t cbOld, void *pvOld, size_t cbNew, const char *pszTag) RT_NO_THROW_DEF
+{
+    void *pvNew = NULL;
+    int rc = RTMemSaferReallocZExTag(cbOld, pvOld, cbNew, &pvNew, 0 /*fFlags*/, pszTag);
+    if (RT_SUCCESS(rc))
+        return pvNew;
+    return NULL;
+}
+RT_EXPORT_SYMBOL(RTMemSaferReallocZTag);
+