Adding upstream version 6.0.4-dfsg.upstream/6.0.4-dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 652 insertions, 0 deletions

diff --git a/src/VBox/Runtime/common/crypto/pemfile.cpp b/src/VBox/Runtime/common/crypto/pemfile.cpp
new file mode 100644
index 00000000..b23c3b44
--- /dev/null
+++ b/src/VBox/Runtime/common/crypto/pemfile.cpp
@@ -0,0 +1,652 @@
+/* $Id: pemfile.cpp $ */
+/** @file
+ * IPRT - Crypto - PEM file reader / writer.
+ *
+ * See RFC-1341 for the original ideas for the format, but keep in mind
+ * that the format was hijacked and put to different uses.  We're aiming at
+ * dealing with the different uses rather than anything email related here.
+ */
+
+/*
+ * Copyright (C) 2006-2019 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/crypto/pem.h>
+
+#include <iprt/asm.h>
+#include <iprt/base64.h>
+#include <iprt/ctype.h>
+#include <iprt/err.h>
+#include <iprt/mem.h>
+#include <iprt/memsafer.h>
+#include <iprt/file.h>
+#include <iprt/string.h>
+
+
+
+/**
+ * Looks for a PEM-like marker.
+ *
+ * @returns true if found, false if not.
+ * @param   pbContent           Start of the content to search thru.
+ * @param   cbContent           The size of the content to search.
+ * @param   offStart            The offset into pbContent to start searching.
+ * @param   pszLeadWord         The lead word (BEGIN/END).
+ * @param   cchLeadWord         The length of the lead word.
+ * @param   paMarkers           Pointer to an array of markers.
+ * @param   cMarkers            Number of markers in the array.
+ * @param   ppMatch             Where to return the pointer to the matching
+ *                              marker. Optional.
+ * @param   poffBegin           Where to return the start offset of the marker.
+ *                              Optional.
+ * @param   poffEnd             Where to return the end offset of the marker
+ *                              (trailing whitespace and newlines will be
+ *                              skipped).  Optional.
+ */
+static bool rtCrPemFindMarker(uint8_t const *pbContent, size_t cbContent, size_t offStart,
+                              const char *pszLeadWord, size_t cchLeadWord, PCRTCRPEMMARKER paMarkers, size_t cMarkers,
+                              PCRTCRPEMMARKER *ppMatch, size_t *poffBegin, size_t *poffEnd)
+{
+    /* Remember the start of the content for the purpose of calculating offsets. */
+    uint8_t const * const pbStart = pbContent;
+
+    /* Skip adhead by offStart */
+    if (offStart >= cbContent)
+        return false;
+    pbContent += offStart;
+    cbContent -= offStart;
+
+    /*
+     * Search the content.
+     */
+    while (cbContent > 6)
+    {
+        /*
+         * Look for dashes.
+         */
+        uint8_t const *pbStartSearch = pbContent;
+        pbContent = (uint8_t const *)memchr(pbContent, '-', cbContent);
+        if (!pbContent)
+            break;
+
+        cbContent -= pbContent - pbStartSearch;
+        if (cbContent < 6)
+            break;
+
+        /*
+         * There must be at least three to interest us.
+         */
+        if (   pbContent[1] == '-'
+            && pbContent[2] == '-')
+        {
+            unsigned cDashes = 3;
+            while (cDashes < cbContent && pbContent[cDashes] == '-')
+                cDashes++;
+
+            if (poffBegin)
+                *poffBegin = pbContent - pbStart;
+            cbContent -= cDashes;
+            pbContent += cDashes;
+
+            /*
+             * Match lead word.
+             */
+            if (   cbContent > cchLeadWord
+                && memcmp(pbContent, pszLeadWord, cchLeadWord) == 0
+                && RT_C_IS_BLANK(pbContent[cchLeadWord]) )
+            {
+                pbContent += cchLeadWord;
+                cbContent -= cchLeadWord;
+                while (cbContent > 0 && RT_C_IS_BLANK(*pbContent))
+                {
+                    pbContent++;
+                    cbContent--;
+                }
+
+                /*
+                 * Match one of the specified markers.
+                 */
+                uint8_t const  *pbSavedContent = pbContent;
+                size_t  const   cbSavedContent = cbContent;
+                for (uint32_t iMarker = 0; iMarker < cMarkers; iMarker++)
+                {
+                    pbContent = pbSavedContent;
+                    cbContent = cbSavedContent;
+
+                    uint32_t            cWords = paMarkers[iMarker].cWords;
+                    PCRTCRPEMMARKERWORD pWord  = paMarkers[iMarker].paWords;
+                    while (cWords > 0)
+                    {
+                        uint32_t const cchWord = pWord->cchWord;
+                        if (cbContent <= cchWord)
+                            break;
+                        if (memcmp(pbContent, pWord->pszWord, cchWord))
+                            break;
+                        pbContent += cchWord;
+                        cbContent -= cchWord;
+
+                        if (!cbContent)
+                            break;
+                        if (RT_C_IS_BLANK(*pbContent))
+                            do
+                            {
+                                pbContent++;
+                                cbContent--;
+                            } while (cbContent > 0 && RT_C_IS_BLANK(*pbContent));
+                        else if (cWords > 1 || pbContent[0] != '-')
+                            break;
+
+                        cWords--;
+                        if (cWords == 0)
+                        {
+                            /*
+                             * If there are three or more dashes following now, we've got a hit.
+                             */
+                            if (   cbContent > 3
+                                && pbContent[0] == '-'
+                                && pbContent[1] == '-'
+                                && pbContent[2] == '-')
+                            {
+                                cDashes = 3;
+                                while (cDashes < cbContent && pbContent[cDashes] == '-')
+                                    cDashes++;
+                                cbContent -= cDashes;
+                                pbContent += cDashes;
+
+                                /*
+                                 * Skip spaces and newline.
+                                 */
+                                while (cbContent > 0 && RT_C_IS_SPACE(*pbContent))
+                                    pbContent++, cbContent--;
+                                if (poffEnd)
+                                    *poffEnd = pbContent - pbStart;
+                                if (ppMatch)
+                                    *ppMatch = &paMarkers[iMarker];
+                                return true;
+                            }
+                            break;
+                        }
+                        pWord++;
+                    } /* for each word in marker. */
+                } /* for each marker. */
+            }
+        }
+        else
+        {
+            pbContent++;
+            cbContent--;
+        }
+    }
+
+    return false;
+}
+
+
+static bool rtCrPemFindMarkerSection(uint8_t const *pbContent, size_t cbContent, size_t offStart,
+                                     PCRTCRPEMMARKER paMarkers, size_t cMarkers,
+                                     PCRTCRPEMMARKER *ppMatch, size_t *poffBegin, size_t *poffEnd, size_t *poffResume)
+{
+    /** @todo Detect BEGIN / END mismatch. */
+    PCRTCRPEMMARKER pMatch;
+    if (rtCrPemFindMarker(pbContent, cbContent, offStart, "BEGIN", 5, paMarkers, cMarkers,
+                          &pMatch, NULL /*poffStart*/, poffBegin))
+    {
+        if (rtCrPemFindMarker(pbContent, cbContent, *poffBegin, "END", 3, pMatch, 1,
+                              NULL /*ppMatch*/, poffEnd, poffResume))
+        {
+            *ppMatch = pMatch;
+            return true;
+        }
+    }
+    *ppMatch = NULL;
+    return false;
+}
+
+
+/**
+ * Parses any fields the message may contain.
+ *
+ * @retval  VINF_SUCCESS
+ * @retval  VERR_NO_MEMORY
+ * @retval  VERR_CR_MALFORMED_PEM_HEADER
+ *
+ * @param   pSection        The current section, where we will attach a list of
+ *                          fields to the pFieldHead member.
+ * @param   pbContent       The content of the PEM message being parsed.
+ * @param   cbContent       The length of the PEM message.
+ * @param   pcbFields       Where to return the length of the header fields we found.
+ */
+static int rtCrPemProcessFields(PRTCRPEMSECTION pSection, uint8_t const *pbContent, size_t cbContent, size_t *pcbFields)
+{
+    uint8_t const * const pbContentStart = pbContent;
+
+    /*
+     * Work the encapulated header protion field by field.
+     *
+     * This is optional, so currently we don't throw errors here but leave that
+     * to when we work the text portion with the base64 decoder.  Also, as a reader
+     * we don't go all pedanic on confirming to specification (RFC-1421), especially
+     * given that it's used for crypto certificates, keys and the like not email. :-)
+     */
+    PCRTCRPEMFIELD *ppNext = &pSection->pFieldHead;
+    while (cbContent > 0)
+    {
+        /* Just look for a colon first. */
+        const uint8_t *pbColon = (const uint8_t *)memchr(pbContent, ':', cbContent);
+        if (!pbColon)
+            break;
+        size_t offColon = pbColon - pbContent;
+
+        /* Check that the colon is within the first line. */
+        if (!memchr(pbContent, '\n', cbContent - offColon))
+            return VERR_CR_MALFORMED_PEM_HEADER;
+
+        /* Skip leading spaces (there shouldn't be any, but just in case). */
+        while (RT_C_IS_BLANK(*pbContent) && /*paranoia:*/ offColon > 0)
+        {
+            offColon--;
+            cbContent--;
+            pbContent++;
+        }
+
+        /* There shouldn't be any spaces before the colon, but just in case */
+        size_t cchName = offColon;
+        while (cchName > 0 && RT_C_IS_BLANK(pbContent[cchName - 1]))
+            cchName--;
+
+        /* Skip leading value spaces (there typically is at least one). */
+        size_t offValue = offColon + 1;
+        while (offValue < cbContent && RT_C_IS_BLANK(pbContent[offValue]))
+            offValue++;
+
+        /* Find the newline the field value ends with and where the next iteration should start later on. */
+        size_t         cbLeft;
+        uint8_t const *pbNext = (uint8_t const *)memchr(&pbContent[offValue], '\n', cbContent - offValue);
+        while (   pbNext
+               && (cbLeft = pbNext - pbContent) < cbContent
+               && RT_C_IS_BLANK(pbNext[1]) /* next line must start with a space or tab */)
+            pbNext = (uint8_t const *)memchr(&pbNext[1], '\n', cbLeft - 1);
+
+        size_t cchValue;
+        if (pbNext)
+        {
+            cchValue = pbNext - &pbContent[offValue];
+            if (cchValue > 0 && pbNext[-1] == '\r')
+                cchValue--;
+            pbNext++;
+        }
+        else
+        {
+            cchValue = cbContent - offValue;
+            pbNext = &pbContent[cbContent];
+        }
+
+        /* Strip trailing spaces. */
+        while (cchValue > 0 && RT_C_IS_BLANK(pbContent[offValue + cchValue - 1]))
+            cchValue--;
+
+        /*
+         * Allocate a field instance.
+         *
+         * Note! We don't consider field data sensitive at the moment.  This
+         *       mainly because the fields are chiefly used to indicate the
+         *       encryption parameters to the body.
+         */
+        PRTCRPEMFIELD pNewField = (PRTCRPEMFIELD)RTMemAllocZVar(sizeof(*pNewField) + cchName + 1 + cchValue + 1);
+        if (!pNewField)
+            return VERR_NO_MEMORY;
+        pNewField->cchName         = cchName;
+        pNewField->cchValue        = cchValue;
+        memcpy(pNewField->szName, pbContent, cchName);
+        pNewField->szName[cchName] = '\0';
+        char *pszDst = (char *)memcpy(&pNewField->szName[cchName + 1], &pbContent[offValue], cchValue);
+        pNewField->pszValue        = pszDst;
+        pszDst[cchValue]           = '\0';
+        pNewField->pNext           = NULL;
+
+        *ppNext = pNewField;
+        ppNext = &pNewField->pNext;
+
+        /*
+         * Advance past the field.
+         */
+        cbContent -= pbNext - pbContent;
+        pbContent  = pbNext;
+    }
+
+    /*
+     * Skip blank line(s) before the body.
+     */
+    while (cbContent >= 1)
+    {
+        size_t cbSkip;
+        if (pbContent[0] == '\n')
+            cbSkip = 1;
+        else if (   pbContent[0] == '\r'
+                 && cbContent >= 2
+                 && pbContent[1] == '\n')
+            cbSkip = 2;
+        else
+            break;
+        pbContent += cbSkip;
+        cbContent -= cbSkip;
+    }
+
+    *pcbFields = pbContent - pbContentStart;
+    return VINF_SUCCESS;
+}
+
+
+/**
+ * Does the decoding of a PEM-like data blob after it has been located.
+ *
+ * @returns IPRT status ocde
+ * @param   pbContent           The start of the PEM-like content (text).
+ * @param   cbContent           The max size of the PEM-like content.
+ * @param   fSensitive          Set if the safer allocator should be used.
+ * @param   ppvDecoded          Where to return a heap block containing the
+ *                              decoded content.
+ * @param   pcbDecoded          Where to return the size of the decoded content.
+ */
+static int rtCrPemDecodeBase64(uint8_t const *pbContent, size_t cbContent, bool fSensitive,
+                               void **ppvDecoded, size_t *pcbDecoded)
+{
+    ssize_t cbDecoded = RTBase64DecodedSizeEx((const char *)pbContent, cbContent, NULL);
+    if (cbDecoded < 0)
+        return VERR_INVALID_BASE64_ENCODING;
+
+    *pcbDecoded = cbDecoded;
+    void *pvDecoded = !fSensitive ? RTMemAlloc(cbDecoded) : RTMemSaferAllocZ(cbDecoded);
+    if (!pvDecoded)
+        return VERR_NO_MEMORY;
+
+    size_t cbActual;
+    int rc = RTBase64DecodeEx((const char *)pbContent, cbContent, pvDecoded, cbDecoded, &cbActual, NULL);
+    if (RT_SUCCESS(rc))
+    {
+        if (cbActual == (size_t)cbDecoded)
+        {
+            *ppvDecoded = pvDecoded;
+            return VINF_SUCCESS;
+        }
+
+        rc = VERR_INTERNAL_ERROR_3;
+    }
+    if (!fSensitive)
+        RTMemFree(pvDecoded);
+    else
+        RTMemSaferFree(pvDecoded, cbDecoded);
+    return rc;
+}
+
+
+/**
+ * Checks if the content of a file looks to be binary or not.
+ *
+ * @returns true if likely to be binary, false if not binary.
+ * @param   pbFile              The file bytes to scan.
+ * @param   cbFile              The number of bytes.
+ * @param   fFlags              RTCRPEMREADFILE_F_XXX
+ */
+static bool rtCrPemIsBinaryBlob(uint8_t const *pbFile, size_t cbFile, uint32_t fFlags)
+{
+    if (fFlags & RTCRPEMREADFILE_F_ONLY_PEM)
+        return false;
+
+    /*
+     * Well formed PEM files should probably only contain 7-bit ASCII and
+     * restrict thenselfs to the following control characters:
+     *      tab, newline, return, form feed
+     *
+     * However, if we want to read PEM files which contains human readable
+     * certificate details before or after each base-64 section, we can't stick
+     * to 7-bit ASCII.  We could say it must be UTF-8, but that's probably to
+     * limited as well.  So, we'll settle for detecting binary files by control
+     * characters alone (safe enough for DER encoded stuff, I think).
+     */
+    while (cbFile-- > 0)
+    {
+        uint8_t const b = *pbFile++;
+        if (b < 32 && b != '\t' && b != '\n' && b != '\r' && b != '\f')
+        {
+            /* Ignore EOT (4), SUB (26) and NUL (0) at the end of the file. */
+            if (   (b == 4 || b == 26)
+                && (   cbFile == 0
+                    || (   cbFile == 1
+                        && *pbFile == '\0')))
+                return false;
+
+            if (b == 0 && cbFile == 0)
+                return false;
+
+            return true;
+        }
+    }
+    return false;
+}
+
+
+RTDECL(int) RTCrPemFreeSections(PCRTCRPEMSECTION pSectionHead)
+{
+    while (pSectionHead != NULL)
+    {
+        PRTCRPEMSECTION pFree = (PRTCRPEMSECTION)pSectionHead;
+        pSectionHead = pSectionHead->pNext;
+        ASMCompilerBarrier(); /* paranoia */
+
+        if (pFree->pbData)
+        {
+            if (!pFree->fSensitive)
+                RTMemFree(pFree->pbData);
+            else
+                RTMemSaferFree(pFree->pbData, pFree->cbData);
+            pFree->pbData = NULL;
+            pFree->cbData = 0;
+        }
+
+        PRTCRPEMFIELD pField = (PRTCRPEMFIELD)pFree->pFieldHead;
+        if (pField)
+        {
+            pFree->pFieldHead = NULL;
+            do
+            {
+                PRTCRPEMFIELD pFreeField = pField;
+                pField = (PRTCRPEMFIELD)pField->pNext;
+                ASMCompilerBarrier(); /* paranoia */
+
+                pFreeField->pszValue = NULL;
+                RTMemFree(pFreeField);
+            } while (pField);
+        }
+
+        RTMemFree(pFree);
+    }
+    return VINF_SUCCESS;
+}
+
+
+RTDECL(int) RTCrPemParseContent(void const *pvContent, size_t cbContent, uint32_t fFlags,
+                                PCRTCRPEMMARKER paMarkers, size_t cMarkers,
+                                PCRTCRPEMSECTION *ppSectionHead, PRTERRINFO pErrInfo)
+{
+    RT_NOREF_PV(pErrInfo);
+
+    /*
+     * Input validation.
+     */
+    AssertPtr(ppSectionHead);
+    *ppSectionHead = NULL;
+    AssertReturn(cbContent, VINF_EOF);
+    AssertPtr(pvContent);
+    AssertPtr(paMarkers);
+    AssertReturn(!(fFlags & ~RTCRPEMREADFILE_F_VALID_MASK), VERR_INVALID_FLAGS);
+
+    /*
+     * Pre-allocate a section.
+     */
+    int rc = VINF_SUCCESS;
+    PRTCRPEMSECTION pSection = (PRTCRPEMSECTION)RTMemAllocZ(sizeof(*pSection));
+    if (pSection)
+    {
+        bool const fSensitive = RT_BOOL(fFlags & RTCRPEMREADFILE_F_SENSITIVE);
+
+        /*
+         * Try locate the first section.
+         */
+        uint8_t const  *pbContent = (uint8_t const *)pvContent;
+        size_t          offBegin, offEnd, offResume;
+        PCRTCRPEMMARKER pMatch;
+        if (   !rtCrPemIsBinaryBlob(pbContent, cbContent, fFlags)
+            && rtCrPemFindMarkerSection(pbContent, cbContent, 0 /*offStart*/, paMarkers, cMarkers,
+                                        &pMatch, &offBegin, &offEnd, &offResume) )
+        {
+            PCRTCRPEMSECTION *ppNext = ppSectionHead;
+            for (;;)
+            {
+                //pSection->pNext       = NULL;
+                pSection->pMarker       = pMatch;
+                //pSection->pbData      = NULL;
+                //pSection->cbData      = 0;
+                //pSection->pFieldHead  = NULL;
+                pSection->fSensitive    = fSensitive;
+
+                *ppNext = pSection;
+                ppNext = &pSection->pNext;
+
+                /*
+                 * Decode the section.
+                 */
+                size_t cbFields = 0;
+                int rc2 = rtCrPemProcessFields(pSection, pbContent + offBegin, offEnd - offBegin, &cbFields);
+                offBegin += cbFields;
+                if (RT_SUCCESS(rc2))
+                    rc2 = rtCrPemDecodeBase64(pbContent + offBegin, offEnd - offBegin, fSensitive,
+                                              (void **)&pSection->pbData, &pSection->cbData);
+                if (RT_FAILURE(rc2))
+                {
+                    pSection->pbData = NULL;
+                    pSection->cbData = 0;
+                    if (   rc2 == VERR_INVALID_BASE64_ENCODING
+                        && (fFlags & RTCRPEMREADFILE_F_CONTINUE_ON_ENCODING_ERROR))
+                        rc = -rc2;
+                    else
+                    {
+                        rc = rc2;
+                        break;
+                    }
+                }
+
+                /*
+                 * More sections?
+                 */
+                if (   offResume + 12 >= cbContent
+                    || offResume      >= cbContent
+                    || !rtCrPemFindMarkerSection(pbContent, cbContent, offResume, paMarkers, cMarkers,
+                                                 &pMatch, &offBegin, &offEnd, &offResume) )
+                    break; /* No. */
+
+                /* Ok, allocate a new record for it. */
+                pSection = (PRTCRPEMSECTION)RTMemAllocZ(sizeof(*pSection));
+                if (RT_UNLIKELY(!pSection))
+                {
+                    rc = VERR_NO_MEMORY;
+                    break;
+                }
+            }
+            if (RT_SUCCESS(rc))
+                return rc;
+
+            RTCrPemFreeSections(*ppSectionHead);
+        }
+        else
+        {
+            if (!(fFlags & RTCRPEMREADFILE_F_ONLY_PEM))
+            {
+                /*
+                 * No PEM section found.  Return the whole file as one binary section.
+                 */
+                //pSection->pNext       = NULL;
+                //pSection->pMarker     = NULL;
+                //pSection->pFieldHead  = NULL;
+                pSection->cbData        = cbContent;
+                pSection->fSensitive    = fSensitive;
+                if (!fSensitive)
+                    pSection->pbData    = (uint8_t *)RTMemDup(pbContent, cbContent);
+                else
+                {
+                    pSection->pbData    = (uint8_t *)RTMemSaferAllocZ(cbContent);
+                    if (pSection->pbData)
+                        memcpy(pSection->pbData, pbContent, cbContent);
+                }
+                if (pSection->pbData)
+                {
+                    *ppSectionHead = pSection;
+                    return VINF_SUCCESS;
+                }
+
+                rc = VERR_NO_MEMORY;
+            }
+            else
+                rc = VWRN_NOT_FOUND;
+            RTMemFree(pSection);
+        }
+    }
+    else
+        rc = VERR_NO_MEMORY;
+    *ppSectionHead = NULL;
+    return rc;
+}
+
+
+RTDECL(int) RTCrPemReadFile(const char *pszFilename, uint32_t fFlags, PCRTCRPEMMARKER paMarkers, size_t cMarkers,
+                            PCRTCRPEMSECTION *ppSectionHead, PRTERRINFO pErrInfo)
+{
+    *ppSectionHead = NULL;
+    AssertReturn(!(fFlags & ~RTCRPEMREADFILE_F_VALID_MASK), VERR_INVALID_FLAGS);
+
+    size_t      cbContent;
+    void        *pvContent;
+    int rc = RTFileReadAllEx(pszFilename, 0, 64U*_1M, RTFILE_RDALL_O_DENY_WRITE, &pvContent, &cbContent);
+    if (RT_SUCCESS(rc))
+    {
+        rc = RTCrPemParseContent(pvContent, cbContent, fFlags, paMarkers, cMarkers, ppSectionHead, pErrInfo);
+        if (fFlags & RTCRPEMREADFILE_F_SENSITIVE)
+            RTMemWipeThoroughly(pvContent, cbContent, 3);
+        RTFileReadAllFree(pvContent, cbContent);
+    }
+    else
+        rc = RTErrInfoSetF(pErrInfo, rc, "RTFileReadAllEx failed with %Rrc on '%s'", rc, pszFilename);
+    return rc;
+}
+
+
+RTDECL(const char *) RTCrPemFindFirstSectionInContent(void const *pvContent, size_t cbContent,
+                                                      PCRTCRPEMMARKER paMarkers, size_t cMarkers)
+{
+    size_t offBegin;
+    if (rtCrPemFindMarker((uint8_t *)pvContent, cbContent, 0, "BEGIN", 5, paMarkers, cMarkers, NULL, &offBegin, NULL))
+        return (const char *)pvContent + offBegin;
+    return NULL;
+}