зеркало из https://github.com/mozilla/gecko-dev.git
Bug 1639552 - Integrate IPCStreamCipherStrategy into ObfuscatingVFS. r=dom-workers-and-storage-reviewers,janv
Differential Revision: https://phabricator.services.mozilla.com/D76141
This commit is contained in:
Simon Giesecke
Родитель
80cee3b558
Коммит
2cd9c3bd8e
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@ -11,7 +11,7 @@
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******************************************************************************
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**
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** This file implements a VFS shim that obfuscates database content
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** written to disk by XOR-ing a hex pattern passed in as a query parameter.
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** written to disk by applying a CipherStrategy.
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**
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** COMPILING
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**
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@ -108,6 +108,9 @@ SQLITE_EXTENSION_INIT1
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#include <ctype.h>
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#include <stdio.h> /* For debugging only */
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#include "mozilla/dom/quota/IPCStreamCipherStrategy.h"
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#include "mozilla/ScopeExit.h"
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/*
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** Forward declaration of objects used by this utility
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*/
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@ -127,24 +130,25 @@ typedef unsigned char u8;
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#define ORIGVFS(p) ((sqlite3_vfs*)((p)->pAppData))
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#define ORIGFILE(p) ((sqlite3_file*)(((ObfsFile*)(p)) + 1))
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/*
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** Size of the obfuscation key
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*/
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#define OBFS_KEYSZ 32
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/*
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** Database page size for obfuscated databases
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*/
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#define OBFS_PGSZ 8192
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using namespace mozilla;
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using namespace mozilla::dom::quota;
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/* An open file */
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struct ObfsFile {
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sqlite3_file base; /* IO methods */
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const char* zFName; /* Original name of the file */
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char inCkpt; /* Currently doing a checkpoint */
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ObfsFile* pPartner; /* Ptr from WAL to main-db, or from main-db to WAL */
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void* pTemp; /* Temporary storage for encoded pages */
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u8 aKey[OBFS_KEYSZ]; /* Obfuscation key */
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sqlite3_file base; /* IO methods */
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const char* zFName; /* Original name of the file */
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char inCkpt; /* Currently doing a checkpoint */
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ObfsFile* pPartner; /* Ptr from WAL to main-db, or from main-db to WAL */
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void* pTemp; /* Temporary storage for encoded pages */
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IPCStreamCipherStrategy*
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encryptCipherStrategy; /* CipherStrategy for encryption */
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IPCStreamCipherStrategy*
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decryptCipherStrategy; /* CipherStrategy for decryption */
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};
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/*
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@ -236,28 +240,36 @@ static const sqlite3_io_methods obfs_io_methods = {
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obfsUnfetch /* xUnfetch */
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};
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/* Obfuscate a page using the key in p->aKey[].
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static constexpr int kKeyBytes = 32;
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static constexpr int kIvBytes = IPCStreamCipherStrategy::BlockPrefixLength;
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static constexpr int kClearTextPrefixBytesOnFirstPage = 32;
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static constexpr int kReservedBytes = 32;
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static constexpr int kBasicBlockSize = IPCStreamCipherStrategy::BasicBlockSize;
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static_assert(kClearTextPrefixBytesOnFirstPage % kBasicBlockSize == 0);
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static_assert(kReservedBytes % kBasicBlockSize == 0);
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/* Obfuscate a page using p->encryptCipherStrategy.
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**
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** A new random nonce is created and stored in the last 32 bytes
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** of the page. All other bytes of the page are XOR-ed against both
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** the key and the nonce. Except, for page-1 (including the SQLite
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** of the page. All other bytes of the page are obfuscasted using the
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** CipherStrategy. Except, for page-1 (including the SQLite
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** database header) the first 32 bytes are not obfuscated
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**
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** Return a pointer to the obfuscated content, which is held in the
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** p->aTemp buffer. Or return a NULL pointer if something goes wrong.
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** p->pTemp buffer. Or return a NULL pointer if something goes wrong.
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** Errors are reported using sqlite3_log().
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*/
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static void* obfsEncode(
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ObfsFile* p, /* File containing page to be obfuscated */
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u8* a, /* database page to be obfuscated */
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int nByte /* Bytes of content in a[]. Must be a multiple of OBFS_KEYSZ. */
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static void* obfsEncode(ObfsFile* p, /* File containing page to be obfuscated */
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u8* a, /* database page to be obfuscated */
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int nByte /* Bytes of content in a[]. Must be a multiple
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of kBasicBlockSize. */
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) {
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u8 aKey[OBFS_KEYSZ];
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u8 aIv[kIvBytes];
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u8* pOut;
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int i;
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assert((OBFS_KEYSZ & (OBFS_KEYSZ - 1)) == 0);
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sqlite3_randomness(OBFS_KEYSZ, aKey);
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static_assert((kIvBytes & (kIvBytes - 1)) == 0);
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sqlite3_randomness(kIvBytes, aIv);
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pOut = (u8*)p->pTemp;
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if (pOut == 0) {
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pOut = static_cast<u8*>(sqlite3_malloc64(nByte));
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@ -268,60 +280,58 @@ static void* obfsEncode(
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p->zFName);
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return 0;
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}
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}
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memcpy(pOut + nByte - OBFS_KEYSZ, aKey, OBFS_KEYSZ);
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for (i = 0; i < OBFS_KEYSZ; i++) {
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aKey[i] ^= p->aKey[i];
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p->pTemp = pOut;
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}
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if (memcmp(a, "SQLite format 3", 16) == 0) {
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i = OBFS_KEYSZ;
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if (a[20] != OBFS_KEYSZ) {
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i = kClearTextPrefixBytesOnFirstPage;
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if (a[20] != kReservedBytes) {
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sqlite3_log(SQLITE_IOERR,
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"obfuscated database must have reserve-bytes"
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"obfuscated database must have reserved-bytes"
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" set to %d",
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OBFS_KEYSZ);
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return 0;
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kReservedBytes);
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return nullptr;
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}
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memcpy(pOut, a, OBFS_KEYSZ);
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memcpy(pOut, a, kClearTextPrefixBytesOnFirstPage);
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} else {
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i = 0;
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}
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while (i < nByte - OBFS_KEYSZ) {
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pOut[i] = aKey[i & (OBFS_KEYSZ - 1)] ^ a[i];
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i++;
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}
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const int payloadLength = nByte - kReservedBytes - i;
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MOZ_ASSERT(payloadLength > 0);
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// XXX I guess this can be done in-place as well, then we don't need the
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// temporary page at all, I guess?
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p->encryptCipherStrategy->Cipher(
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Span{aIv}, Span{a + i, static_cast<unsigned>(payloadLength)},
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Span{pOut + i, static_cast<unsigned>(payloadLength)});
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memcpy(pOut + nByte - kReservedBytes, aIv, kIvBytes);
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return pOut;
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}
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/* De-obfuscate a page using the key in p->aKey[].
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/* De-obfuscate a page using p->decryptCipherStrategy.
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**
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** Deobfuscation consists of XORing all bytes against both the key
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** and the nonce stored in the last 32-bytes of the page. The
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** deobfuscation is done in-place.
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** The deobfuscation is done in-place.
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**
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** For pages that begin with the SQLite header text, the first
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** 32 bytes are not deobfuscated.
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*/
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static void obfsDecode(
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ObfsFile* p, /* File containing page to be obfuscated */
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u8* a, /* database page to be obfuscated */
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int nByte /* Bytes of content in a[]. Must be a multiple of OBFS_KEYSZ. */
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static void obfsDecode(ObfsFile* p, /* File containing page to be obfuscated */
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u8* a, /* database page to be obfuscated */
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int nByte /* Bytes of content in a[]. Must be a multiple
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of kBasicBlockSize. */
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) {
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u8 aKey[OBFS_KEYSZ];
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int i;
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for (i = 0; i < OBFS_KEYSZ; i++) {
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aKey[i] = p->aKey[i] ^ a[i + nByte - OBFS_KEYSZ];
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}
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if (memcmp(a, "SQLite format 3", 16) == 0) {
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i = OBFS_KEYSZ;
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i = kClearTextPrefixBytesOnFirstPage;
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} else {
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i = 0;
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}
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while (i < nByte - OBFS_KEYSZ) {
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a[i] ^= aKey[i & (OBFS_KEYSZ - 1)];
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i++;
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}
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const int payloadLength = nByte - kReservedBytes - i;
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MOZ_ASSERT(payloadLength > 0);
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p->decryptCipherStrategy->Cipher(
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Span{a + nByte - kReservedBytes, kIvBytes},
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Span{a + i, static_cast<unsigned>(payloadLength)},
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Span{a + i, static_cast<unsigned>(payloadLength)});
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}
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/*
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@ -335,6 +345,10 @@ static int obfsClose(sqlite3_file* pFile) {
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p->pPartner = 0;
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}
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sqlite3_free(p->pTemp);
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delete p->decryptCipherStrategy;
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delete p->encryptCipherStrategy;
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pFile = ORIGFILE(pFile);
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return pFile->pMethods->xClose(pFile);
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}
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@ -345,7 +359,7 @@ static int obfsClose(sqlite3_file* pFile) {
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** If the file is less than one full page in length, then return
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** a substitute "prototype" page-1. This prototype page one
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** specifies a database in WAL mode with an 8192-byte page size
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** and a 32-byte reserve-byte value. Those settings are necessary
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** and a 32-byte reserved-bytes value. Those settings are necessary
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** for obfuscation to function correctly.
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*/
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static int obfsRead(sqlite3_file* pFile, void* zBuf, int iAmt,
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@ -360,9 +374,10 @@ static int obfsRead(sqlite3_file* pFile, void* zBuf, int iAmt,
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}
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} else if (SQLITE_IOERR_SHORT_READ && iOfst == 0 && iAmt >= 100) {
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static const unsigned char aEmptyDb[] = {
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0x53, 0x51, 0x4c, 0x69, 0x74, 0x65, 0x20, 0x66, 0x6f, 0x72, 0x6d,
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0x61, 0x74, 0x20, 0x33, 0x00, 0x20, 0x00, 0x02, 0x02, 0x20, 0x40,
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0x20, 0x20, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01};
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0x53, 0x51, 0x4c, 0x69, 0x74, 0x65, 0x20, 0x66,
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0x6f, 0x72, 0x6d, 0x61, 0x74, 0x20, 0x33, 0x00,
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0x20, 0x00, 0x02, 0x02, kReservedBytes, 0x40, 0x20, 0x20,
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0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01};
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memcpy(zBuf, aEmptyDb, sizeof(aEmptyDb));
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memset(((u8*)zBuf) + sizeof(aEmptyDb), 0, iAmt - sizeof(aEmptyDb));
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rc = SQLITE_OK;
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@ -546,7 +561,7 @@ static int obfsOpen(sqlite3_vfs* pVfs, const char* zName, sqlite3_file* pFile,
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sqlite3_vfs* pSubVfs;
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int rc, i;
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const char* zKey;
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u8 aKey[OBFS_KEYSZ];
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u8 aKey[kKeyBytes];
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pSubVfs = ORIGVFS(pVfs);
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if (flags &
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(SQLITE_OPEN_MAIN_DB | SQLITE_OPEN_WAL | SQLITE_OPEN_MAIN_JOURNAL)) {
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@ -558,22 +573,43 @@ static int obfsOpen(sqlite3_vfs* pVfs, const char* zName, sqlite3_file* pFile,
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return pSubVfs->xOpen(pSubVfs, zName, pFile, flags, pOutFlags);
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}
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for (i = 0;
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i < OBFS_KEYSZ && isxdigit(zKey[i * 2]) && isxdigit(zKey[i * 2 + 1]);
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i < kKeyBytes && isxdigit(zKey[i * 2]) && isxdigit(zKey[i * 2 + 1]);
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i++) {
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aKey[i] = (obfsHexToInt(zKey[i * 2]) << 8) | obfsHexToInt(zKey[i * 2 + 1]);
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aKey[i] = (obfsHexToInt(zKey[i * 2]) << 4) | obfsHexToInt(zKey[i * 2 + 1]);
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}
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if (i != OBFS_KEYSZ) {
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if (i != kKeyBytes) {
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sqlite3_log(SQLITE_CANTOPEN, "invalid query parameter on %s: key=%s", zName,
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zKey);
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return SQLITE_CANTOPEN;
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}
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p = (ObfsFile*)pFile;
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memset(p, 0, sizeof(*p));
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memcpy(p->aKey, aKey, sizeof(aKey));
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auto encryptCipherStrategy = MakeUnique<IPCStreamCipherStrategy>();
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auto decryptCipherStrategy = MakeUnique<IPCStreamCipherStrategy>();
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auto resetMethods = MakeScopeExit([pFile] { pFile->pMethods = nullptr; });
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if (NS_WARN_IF(NS_FAILED(encryptCipherStrategy->Init(
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CipherMode::Encrypt, Span{aKey, sizeof(aKey)},
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IPCStreamCipherStrategy::MakeBlockPrefix())))) {
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return SQLITE_ERROR;
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}
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if (NS_WARN_IF(NS_FAILED(decryptCipherStrategy->Init(
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CipherMode::Decrypt, Span{aKey, sizeof(aKey)})))) {
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return SQLITE_ERROR;
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}
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pSubFile = ORIGFILE(pFile);
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p->base.pMethods = &obfs_io_methods;
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rc = pSubVfs->xOpen(pSubVfs, zName, pSubFile, flags, pOutFlags);
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if (rc) goto obfs_open_done;
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if (rc) {
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return rc;
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}
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resetMethods.release();
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if (flags & (SQLITE_OPEN_WAL | SQLITE_OPEN_MAIN_JOURNAL)) {
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sqlite3_file* pDb = sqlite3_database_file_object(zName);
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p->pPartner = (ObfsFile*)pDb;
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@ -581,9 +617,11 @@ static int obfsOpen(sqlite3_vfs* pVfs, const char* zName, sqlite3_file* pFile,
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p->pPartner->pPartner = p;
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}
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p->zFName = zName;
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obfs_open_done:
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if (rc) pFile->pMethods = 0;
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return rc;
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p->encryptCipherStrategy = encryptCipherStrategy.release();
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p->decryptCipherStrategy = decryptCipherStrategy.release();
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return SQLITE_OK;
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}
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/*
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