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Overview
Comment: | Allow the secure-delete setting to be changed at run-time using a pragma. The SQLITE_SECURE_DELETE compile-time option determines the default setting. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
f72f8a870a0fc98a9f2b564ffafe7946 |
User & Date: | drh 2010-02-12 18:18:39.000 |
Original Comment: | All the secure-delete setting to be changed at run-time using a pragma. The SQLITE_SECURE_DELETE compile-time option determines the default setting. |
Context
2010-02-12
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19:46 | Enhancements to the secure_delete pragma to make it easier to use. (check-in: 2bb38bb96f user: drh tags: trunk) | |
18:18 | Allow the secure-delete setting to be changed at run-time using a pragma. The SQLITE_SECURE_DELETE compile-time option determines the default setting. (check-in: f72f8a870a user: drh tags: trunk) | |
2010-02-10
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05:33 | Fix a segfault in fts3 that may occur if the snippet, offsets or matchinfo functions are used in a query that does not contain a MATCH clause. (check-in: 14ab536a96 user: dan tags: trunk) | |
Changes
Changes to src/btree.c.
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1243 1244 1245 1246 1247 1248 1249 | assert( pPage->pBt!=0 ); assert( sqlite3PagerIswriteable(pPage->pDbPage) ); assert( start>=pPage->hdrOffset+6+pPage->childPtrSize ); assert( (start + size)<=pPage->pBt->usableSize ); assert( sqlite3_mutex_held(pPage->pBt->mutex) ); assert( size>=0 ); /* Minimum cell size is 4 */ | | | | | < > | 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 | assert( pPage->pBt!=0 ); assert( sqlite3PagerIswriteable(pPage->pDbPage) ); assert( start>=pPage->hdrOffset+6+pPage->childPtrSize ); assert( (start + size)<=pPage->pBt->usableSize ); assert( sqlite3_mutex_held(pPage->pBt->mutex) ); assert( size>=0 ); /* Minimum cell size is 4 */ if( pPage->pBt->secureDelete ){ /* Overwrite deleted information with zeros when the secure_delete ** option is enabled */ memset(&data[start], 0, size); } /* Add the space back into the linked list of freeblocks. Note that ** even though the freeblock list was checked by btreeInitPage(), ** btreeInitPage() did not detect overlapping cells or ** freeblocks that overlapped cells. Nor does it detect when the ** cell content area exceeds the value in the page header. If these ** situations arise, then subsequent insert operations might corrupt |
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1479 1480 1481 1482 1483 1484 1485 | u16 first; assert( sqlite3PagerPagenumber(pPage->pDbPage)==pPage->pgno ); assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage ); assert( sqlite3PagerGetData(pPage->pDbPage) == data ); assert( sqlite3PagerIswriteable(pPage->pDbPage) ); assert( sqlite3_mutex_held(pBt->mutex) ); | | | < > | 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 | u16 first; assert( sqlite3PagerPagenumber(pPage->pDbPage)==pPage->pgno ); assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage ); assert( sqlite3PagerGetData(pPage->pDbPage) == data ); assert( sqlite3PagerIswriteable(pPage->pDbPage) ); assert( sqlite3_mutex_held(pBt->mutex) ); if( pBt->secureDelete ){ memset(&data[hdr], 0, pBt->usableSize - hdr); } data[hdr] = (char)flags; first = hdr + 8 + 4*((flags&PTF_LEAF)==0 ?1:0); memset(&data[hdr+1], 0, 4); data[hdr+7] = 0; put2byte(&data[hdr+5], pBt->usableSize); pPage->nFree = pBt->usableSize - first; decodeFlags(pPage, flags); |
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1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 | pBt->db = db; sqlite3PagerSetBusyhandler(pBt->pPager, btreeInvokeBusyHandler, pBt); p->pBt = pBt; pBt->pCursor = 0; pBt->pPage1 = 0; pBt->readOnly = sqlite3PagerIsreadonly(pBt->pPager); pBt->pageSize = get2byte(&zDbHeader[16]); if( pBt->pageSize<512 || pBt->pageSize>SQLITE_MAX_PAGE_SIZE || ((pBt->pageSize-1)&pBt->pageSize)!=0 ){ pBt->pageSize = 0; #ifndef SQLITE_OMIT_AUTOVACUUM /* If the magic name ":memory:" will create an in-memory database, then ** leave the autoVacuum mode at 0 (do not auto-vacuum), even if | > > > | 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 | pBt->db = db; sqlite3PagerSetBusyhandler(pBt->pPager, btreeInvokeBusyHandler, pBt); p->pBt = pBt; pBt->pCursor = 0; pBt->pPage1 = 0; pBt->readOnly = sqlite3PagerIsreadonly(pBt->pPager); #ifdef SQLITE_SECURE_DELETE pBt->secureDelete = 1; #endif pBt->pageSize = get2byte(&zDbHeader[16]); if( pBt->pageSize<512 || pBt->pageSize>SQLITE_MAX_PAGE_SIZE || ((pBt->pageSize-1)&pBt->pageSize)!=0 ){ pBt->pageSize = 0; #ifndef SQLITE_OMIT_AUTOVACUUM /* If the magic name ":memory:" will create an in-memory database, then ** leave the autoVacuum mode at 0 (do not auto-vacuum), even if |
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2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 | int sqlite3BtreeMaxPageCount(Btree *p, int mxPage){ int n; sqlite3BtreeEnter(p); n = sqlite3PagerMaxPageCount(p->pBt->pPager, mxPage); sqlite3BtreeLeave(p); return n; } #endif /* !defined(SQLITE_OMIT_PAGER_PRAGMAS) || !defined(SQLITE_OMIT_VACUUM) */ /* ** Change the 'auto-vacuum' property of the database. If the 'autoVacuum' ** parameter is non-zero, then auto-vacuum mode is enabled. If zero, it ** is disabled. The default value for the auto-vacuum property is ** determined by the SQLITE_DEFAULT_AUTOVACUUM macro. | > > > > > > > > > > > > > > > > | 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 | int sqlite3BtreeMaxPageCount(Btree *p, int mxPage){ int n; sqlite3BtreeEnter(p); n = sqlite3PagerMaxPageCount(p->pBt->pPager, mxPage); sqlite3BtreeLeave(p); return n; } /* ** Set the secureDelete flag if newFlag is 0 or 1. If newFlag is -1, ** then make no changes. Always return the value of the secureDelete ** setting after the change. */ int sqlite3BtreeSecureDelete(Btree *p, int newFlag){ int b; sqlite3BtreeEnter(p); if( newFlag>=0 ){ p->pBt->secureDelete = (newFlag!=0) ? 1 : 0; } b = p->pBt->secureDelete; sqlite3BtreeLeave(p); return b; } #endif /* !defined(SQLITE_OMIT_PAGER_PRAGMAS) || !defined(SQLITE_OMIT_VACUUM) */ /* ** Change the 'auto-vacuum' property of the database. If the 'autoVacuum' ** parameter is non-zero, then auto-vacuum mode is enabled. If zero, it ** is disabled. The default value for the auto-vacuum property is ** determined by the SQLITE_DEFAULT_AUTOVACUUM macro. |
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4900 4901 4902 4903 4904 4905 4906 | /* Increment the free page count on pPage1 */ rc = sqlite3PagerWrite(pPage1->pDbPage); if( rc ) goto freepage_out; nFree = get4byte(&pPage1->aData[36]); put4byte(&pPage1->aData[36], nFree+1); | | | | | | | | | | | < > | 4919 4920 4921 4922 4923 4924 4925 4926 4927 4928 4929 4930 4931 4932 4933 4934 4935 4936 4937 4938 4939 4940 4941 4942 4943 | /* Increment the free page count on pPage1 */ rc = sqlite3PagerWrite(pPage1->pDbPage); if( rc ) goto freepage_out; nFree = get4byte(&pPage1->aData[36]); put4byte(&pPage1->aData[36], nFree+1); if( pBt->secureDelete ){ /* If the secure_delete option is enabled, then ** always fully overwrite deleted information with zeros. */ if( (!pPage && (rc = btreeGetPage(pBt, iPage, &pPage, 0))) || (rc = sqlite3PagerWrite(pPage->pDbPage)) ){ goto freepage_out; } memset(pPage->aData, 0, pPage->pBt->pageSize); } /* If the database supports auto-vacuum, write an entry in the pointer-map ** to indicate that the page is free. */ if( ISAUTOVACUUM ){ ptrmapPut(pBt, iPage, PTRMAP_FREEPAGE, 0, &rc); if( rc ) goto freepage_out; |
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4961 4962 4963 4964 4965 4966 4967 | ** to 3.6.0 or later) we should consider fixing the conditional above ** to read "usableSize/4-2" instead of "usableSize/4-8". */ rc = sqlite3PagerWrite(pTrunk->pDbPage); if( rc==SQLITE_OK ){ put4byte(&pTrunk->aData[4], nLeaf+1); put4byte(&pTrunk->aData[8+nLeaf*4], iPage); | < | < | 4980 4981 4982 4983 4984 4985 4986 4987 4988 4989 4990 4991 4992 4993 4994 4995 4996 | ** to 3.6.0 or later) we should consider fixing the conditional above ** to read "usableSize/4-2" instead of "usableSize/4-8". */ rc = sqlite3PagerWrite(pTrunk->pDbPage); if( rc==SQLITE_OK ){ put4byte(&pTrunk->aData[4], nLeaf+1); put4byte(&pTrunk->aData[8+nLeaf*4], iPage); if( pPage && !pBt->secureDelete ){ sqlite3PagerDontWrite(pPage->pDbPage); } rc = btreeSetHasContent(pBt, iPage); } TRACE(("FREE-PAGE: %d leaf on trunk page %d\n",pPage->pgno,pTrunk->pgno)); goto freepage_out; } } |
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5774 5775 5776 5777 5778 5779 5780 | ** later on. ** ** Unless SQLite is compiled in secure-delete mode. In this case, ** the dropCell() routine will overwrite the entire cell with zeroes. ** In this case, temporarily copy the cell into the aOvflSpace[] ** buffer. It will be copied out again as soon as the aSpace[] buffer ** is allocated. */ | | | | < > | 5791 5792 5793 5794 5795 5796 5797 5798 5799 5800 5801 5802 5803 5804 5805 5806 5807 5808 | ** later on. ** ** Unless SQLite is compiled in secure-delete mode. In this case, ** the dropCell() routine will overwrite the entire cell with zeroes. ** In this case, temporarily copy the cell into the aOvflSpace[] ** buffer. It will be copied out again as soon as the aSpace[] buffer ** is allocated. */ if( pBt->secureDelete ){ memcpy(&aOvflSpace[apDiv[i]-pParent->aData], apDiv[i], szNew[i]); apDiv[i] = &aOvflSpace[apDiv[i]-pParent->aData]; } dropCell(pParent, i+nxDiv-pParent->nOverflow, szNew[i], &rc); } } /* Make nMaxCells a multiple of 4 in order to preserve 8-byte ** alignment */ nMaxCells = (nMaxCells + 3)&~3; |
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Changes to src/btree.h.
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77 78 79 80 81 82 83 84 85 86 87 88 89 90 | int sqlite3BtreeClose(Btree*); int sqlite3BtreeSetCacheSize(Btree*,int); int sqlite3BtreeSetSafetyLevel(Btree*,int,int); int sqlite3BtreeSyncDisabled(Btree*); int sqlite3BtreeSetPageSize(Btree *p, int nPagesize, int nReserve, int eFix); int sqlite3BtreeGetPageSize(Btree*); int sqlite3BtreeMaxPageCount(Btree*,int); int sqlite3BtreeGetReserve(Btree*); int sqlite3BtreeSetAutoVacuum(Btree *, int); int sqlite3BtreeGetAutoVacuum(Btree *); int sqlite3BtreeBeginTrans(Btree*,int); int sqlite3BtreeCommitPhaseOne(Btree*, const char *zMaster); int sqlite3BtreeCommitPhaseTwo(Btree*); int sqlite3BtreeCommit(Btree*); | > | 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 | int sqlite3BtreeClose(Btree*); int sqlite3BtreeSetCacheSize(Btree*,int); int sqlite3BtreeSetSafetyLevel(Btree*,int,int); int sqlite3BtreeSyncDisabled(Btree*); int sqlite3BtreeSetPageSize(Btree *p, int nPagesize, int nReserve, int eFix); int sqlite3BtreeGetPageSize(Btree*); int sqlite3BtreeMaxPageCount(Btree*,int); int sqlite3BtreeSecureDelete(Btree*,int); int sqlite3BtreeGetReserve(Btree*); int sqlite3BtreeSetAutoVacuum(Btree *, int); int sqlite3BtreeGetAutoVacuum(Btree *); int sqlite3BtreeBeginTrans(Btree*,int); int sqlite3BtreeCommitPhaseOne(Btree*, const char *zMaster); int sqlite3BtreeCommitPhaseTwo(Btree*); int sqlite3BtreeCommit(Btree*); |
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Changes to src/btreeInt.h.
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403 404 405 406 407 408 409 410 411 412 413 414 415 416 | struct BtShared { Pager *pPager; /* The page cache */ sqlite3 *db; /* Database connection currently using this Btree */ BtCursor *pCursor; /* A list of all open cursors */ MemPage *pPage1; /* First page of the database */ u8 readOnly; /* True if the underlying file is readonly */ u8 pageSizeFixed; /* True if the page size can no longer be changed */ #ifndef SQLITE_OMIT_AUTOVACUUM u8 autoVacuum; /* True if auto-vacuum is enabled */ u8 incrVacuum; /* True if incr-vacuum is enabled */ #endif u16 pageSize; /* Total number of bytes on a page */ u16 usableSize; /* Number of usable bytes on each page */ u16 maxLocal; /* Maximum local payload in non-LEAFDATA tables */ | > | 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 | struct BtShared { Pager *pPager; /* The page cache */ sqlite3 *db; /* Database connection currently using this Btree */ BtCursor *pCursor; /* A list of all open cursors */ MemPage *pPage1; /* First page of the database */ u8 readOnly; /* True if the underlying file is readonly */ u8 pageSizeFixed; /* True if the page size can no longer be changed */ u8 secureDelete; /* True if secure_delete is enabled */ #ifndef SQLITE_OMIT_AUTOVACUUM u8 autoVacuum; /* True if auto-vacuum is enabled */ u8 incrVacuum; /* True if incr-vacuum is enabled */ #endif u16 pageSize; /* Total number of bytes on a page */ u16 usableSize; /* Number of usable bytes on each page */ u16 maxLocal; /* Maximum local payload in non-LEAFDATA tables */ |
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Changes to src/pager.c.
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2871 2872 2873 2874 2875 2876 2877 | /* If there are dirty pages in the page cache with page numbers greater ** than Pager.dbSize, this means sqlite3PagerTruncateImage() was called to ** make the file smaller (presumably by auto-vacuum code). Do not write ** any such pages to the file. ** ** Also, do not write out any page that has the PGHDR_DONT_WRITE flag | | < < | 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 | /* If there are dirty pages in the page cache with page numbers greater ** than Pager.dbSize, this means sqlite3PagerTruncateImage() was called to ** make the file smaller (presumably by auto-vacuum code). Do not write ** any such pages to the file. ** ** Also, do not write out any page that has the PGHDR_DONT_WRITE flag ** set (set by sqlite3PagerDontWrite()). */ if( pgno<=pPager->dbSize && 0==(pList->flags&PGHDR_DONT_WRITE) ){ i64 offset = (pgno-1)*(i64)pPager->pageSize; /* Offset to write */ char *pData; /* Data to write */ /* Encode the database */ CODEC2(pPager, pList->pData, pgno, 6, return SQLITE_NOMEM, pData); |
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4381 4382 4383 4384 4385 4386 4387 | */ #ifndef NDEBUG int sqlite3PagerIswriteable(DbPage *pPg){ return pPg->flags&PGHDR_DIRTY; } #endif | < | 4379 4380 4381 4382 4383 4384 4385 4386 4387 4388 4389 4390 4391 4392 | */ #ifndef NDEBUG int sqlite3PagerIswriteable(DbPage *pPg){ return pPg->flags&PGHDR_DIRTY; } #endif /* ** A call to this routine tells the pager that it is not necessary to ** write the information on page pPg back to the disk, even though ** that page might be marked as dirty. This happens, for example, when ** the page has been added as a leaf of the freelist and so its ** content no longer matters. ** |
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4407 4408 4409 4410 4411 4412 4413 | IOTRACE(("CLEAN %p %d\n", pPager, pPg->pgno)) pPg->flags |= PGHDR_DONT_WRITE; #ifdef SQLITE_CHECK_PAGES pPg->pageHash = pager_pagehash(pPg); #endif } } | < | 4404 4405 4406 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416 4417 | IOTRACE(("CLEAN %p %d\n", pPager, pPg->pgno)) pPg->flags |= PGHDR_DONT_WRITE; #ifdef SQLITE_CHECK_PAGES pPg->pageHash = pager_pagehash(pPg); #endif } } /* ** This routine is called to increment the value of the database file ** change-counter, stored as a 4-byte big-endian integer starting at ** byte offset 24 of the pager file. ** ** If the isDirectMode flag is zero, then this is done by calling |
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Changes to src/pragma.c.
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412 413 414 415 416 417 418 419 420 421 422 423 424 425 | } if( ALWAYS(pBt) ){ newMax = sqlite3BtreeMaxPageCount(pBt, newMax); } returnSingleInt(pParse, "max_page_count", newMax); }else /* ** PRAGMA [database.]page_count ** ** Return the number of pages in the specified database. */ if( sqlite3StrICmp(zLeft,"page_count")==0 ){ int iReg; | > > > > > > > > > > > > > > > > > > > | 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 | } if( ALWAYS(pBt) ){ newMax = sqlite3BtreeMaxPageCount(pBt, newMax); } returnSingleInt(pParse, "max_page_count", newMax); }else /* ** PRAGMA [database.]secure_delete ** PRAGMA [database.]secure_delete=ON/OFF ** ** The first form reports the current setting for the ** secure_delete flag. The second form changes the secure_delete ** flag setting and reports thenew value. */ if( sqlite3StrICmp(zLeft,"secure_delete")==0 ){ Btree *pBt = pDb->pBt; int b = -1; assert( pBt!=0 ); if( zRight ){ b = getBoolean(zRight); } b = sqlite3BtreeSecureDelete(pBt, b); returnSingleInt(pParse, "secure_delete", b); }else /* ** PRAGMA [database.]page_count ** ** Return the number of pages in the specified database. */ if( sqlite3StrICmp(zLeft,"page_count")==0 ){ int iReg; |
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