/**
* Derive an encryption key for a cipher contex key based on the raw password.
*
* If the raw key data is formated as x'hex' and there are exactly enough hex chars to fill
* the key space (i.e 64 hex chars for a 256 bit key) then the key data will be used directly.
*
* Otherwise, a key data will be derived using PBKDF2
*
* returns SQLITE_OK if initialization was successful
* returns SQLITE_NOMEM if the key could't be derived (for instance if pass is null or pass_sz is 0)
*/
static int codec_key_derive(codec_ctx ctx, cipher_ctx c_ctx)
{
CODEC_TRACE("codec_key_derive: entered c_ctx.pass=%s, c_ctx.pass_sz=%d ctx.iv=%d ctx.iv_sz=%d c_ctx.kdf_iter=%d c_ctx.key_sz=%d\n",
c_ctx.pass, c_ctx.pass_sz, c_ctx.iv, c_ctx.iv_sz, c_ctx.key_sz);
if (c_ctx.pass != null && c_ctx.pass_sz > 0)
{ // if pass is not null
if ((c_ctx.pass_sz == (c_ctx.key_sz * 2) + 3) && c_ctx.pass.StartsWith("x'", StringComparison.InvariantCultureIgnoreCase))
{
int n = c_ctx.pass_sz - 3; /* adjust for leading x' and tailing ' */
string z = c_ctx.pass.Substring(2); // + 2; /* adjust lead offset of x' */
CODEC_TRACE("codec_key_derive: deriving key from hex\n");
c_ctx.key = sqlite3HexToBlob(null, z, n);
}
else
{
CODEC_TRACE("codec_key_derive: deriving key using AES256\n");
Rfc2898DeriveBytes k1 = new Rfc2898DeriveBytes(c_ctx.pass, c_ctx.iv, 2010);
c_ctx.key_sz = 32;
c_ctx.key = k1.GetBytes(c_ctx.key_sz);
}
#if NET_2_0
Aes.BlockSize = 0x80;
Aes.FeedbackSize = 8;
Aes.KeySize = 0x100;
Aes.Mode = CipherMode.CBC;
#endif
c_ctx.encryptor = Aes.CreateEncryptor(c_ctx.key, c_ctx.iv);
c_ctx.decryptor = Aes.CreateDecryptor(c_ctx.key, c_ctx.iv);
return(SQLITE_OK);
}
;
return(SQLITE_ERROR);
}
/**
* Derive an encryption key for a cipher contex key based on the raw password.
*
* If the raw key data is formated as x'hex' and there are exactly enough hex chars to fill
* the key space (i.e 64 hex chars for a 256 bit key) then the key data will be used directly.
*
* Otherwise, a key data will be derived using PBKDF2
*
* returns SQLITE_OK if initialization was successful
* returns SQLITE_NOMEM if the key could't be derived (for instance if pass is null or pass_sz is 0)
*/
static int codec_key_derive(codec_ctx ctx, cipher_ctx c_ctx)
{
CODEC_TRACE("codec_key_derive: entered c_ctx.pass=%s, c_ctx.pass_sz=%d ctx.iv=%d ctx.iv_sz=%d c_ctx.kdf_iter=%d c_ctx.key_sz=%d\n",
c_ctx.pass, c_ctx.pass_sz, c_ctx.iv, c_ctx.iv_sz, c_ctx.key_sz);
if (c_ctx.pass != null && c_ctx.pass_sz > 0)
{ // if pass is not null
if ((c_ctx.pass_sz == (c_ctx.key_sz * 2) + 3) && sqlite3StrNICmp(c_ctx.pass, "x'", 2) == 0)
{
int n = c_ctx.pass_sz - 3; /* adjust for leading x' and tailing ' */
string z = c_ctx.pass.Substring(2); // + 2; /* adjust lead offset of x' */
CODEC_TRACE("codec_key_derive: deriving key from hex\n");
c_ctx.key = sqlite3HexToBlob(null, z, n);
}
else
{
CODEC_TRACE("codec_key_derive: deriving key using AES256\n");
Rfc2898DeriveBytes k1 = new Rfc2898DeriveBytes(c_ctx.pass, c_ctx.iv, 2010);
c_ctx.key_sz = 32;
c_ctx.key = k1.GetBytes(c_ctx.key_sz);
}
c_ctx.encryptor = Aes.CreateEncryptor(c_ctx.key, c_ctx.iv);
c_ctx.decryptor = Aes.CreateDecryptor(c_ctx.key, c_ctx.iv);
return(SQLITE_OK);
}
;
return(SQLITE_ERROR);
}
static void sqlite3FreeCodecArg(ref codec_ctx pCodecArg)
{
if (pCodecArg == null)
{
return;
}
codec_ctx_free(ref pCodecArg); // wipe and free allocated memory for the context
}
/**
* Free and wipe memory associated with a cipher_ctx, including the allocated
* read_ctx and write_ctx.
*/
static void codec_ctx_free(ref codec_ctx iCtx)
{
codec_ctx ctx = iCtx;
CODEC_TRACE("codec_ctx_free: entered iCtx=%d\n", iCtx);
cipher_ctx_free(ref ctx.read_ctx);
cipher_ctx_free(ref ctx.write_ctx);
iCtx = new codec_ctx();//codec_free(ctx, sizeof(codec_ctx);
}
static void sqlite3pager_sqlite3PagerSetCodec(
Pager pPager,
dxCodec xCodec,
dxCodecSizeChng xCodecSizeChng,
dxCodecFree xCodecFree,
codec_ctx pCodec
)
{
sqlite3PagerSetCodec(pPager, xCodec, xCodecSizeChng, xCodecFree, pCodec);
}
static int sqlite3CodecAttach(sqlite3 db, int nDb, string zKey, int nKey)
{
Db pDb = db.aDb[nDb];
CODEC_TRACE("sqlite3CodecAttach: entered nDb=%d zKey=%s, nKey=%d\n", nDb, zKey, nKey);
//activate_openssl();
if (zKey != null && pDb.pBt != null)
{
Aes.KeySize = 256;
#if !SQLITE_SILVERLIGHT
Aes.Padding = PaddingMode.None;
#endif
codec_ctx ctx;
int rc;
//Pager pPager = pDb.pBt.pBt.pPager;
//sqlite3_file fd;
ctx = new codec_ctx();//sqlite3Malloc(sizeof(codec_ctx);
//if(ctx == null) return SQLITE_NOMEM;
//memset(ctx, 0, sizeof(codec_ctx); /* initialize all pointers and values to 0 */
ctx.pBt = pDb.pBt; /* assign pointer to database btree structure */
if ((rc = cipher_ctx_init(ref ctx.read_ctx)) != SQLITE_OK)
{
return(rc);
}
if ((rc = cipher_ctx_init(ref ctx.write_ctx)) != SQLITE_OK)
{
return(rc);
}
/* pre-allocate a page buffer of PageSize bytes. This will
* be used as a persistent buffer for encryption and decryption
* operations to avoid overhead of multiple memory allocations*/
ctx.buffer = sqlite3MemMalloc(sqlite3BtreeGetPageSize(ctx.pBt));//sqlite3Malloc(sqlite3BtreeGetPageSize(ctx.pBt);
//if(ctx.buffer == null) return SQLITE_NOMEM;
/* allocate space for salt data. Then read the first 16 bytes header as the salt for the key derivation */
ctx.read_ctx.iv_sz = FILE_HEADER_SZ;
ctx.read_ctx.iv = new byte[ctx.read_ctx.iv_sz];//sqlite3Malloc( ctx.iv_sz );
Buffer.BlockCopy(Encoding.UTF8.GetBytes(SQLITE_FILE_HEADER), 0, ctx.read_ctx.iv, 0, FILE_HEADER_SZ);
sqlite3pager_sqlite3PagerSetCodec(sqlite3BtreePager(pDb.pBt), sqlite3Codec, null, sqlite3FreeCodecArg, ctx);
codec_set_cipher_name(db, nDb, CIPHER, 0);
codec_set_pass_key(db, nDb, zKey, nKey, 0);
cipher_ctx_copy(ctx.write_ctx, ctx.read_ctx);
//sqlite3BtreeSetPageSize( ctx.pBt, sqlite3BtreeGetPageSize( ctx.pBt ), MAX_IV_LENGTH, 0 );
}
return(SQLITE_OK);
}
public codec_ctx Copy()
{
codec_ctx c = new codec_ctx();
c.mode_rekey = mode_rekey;
c.buffer = sqlite3MemMalloc(buffer.Length);
c.pBt = pBt;
if (read_ctx != null)
{
c.read_ctx = read_ctx.Copy();
}
if (write_ctx != null)
{
c.write_ctx = write_ctx.Copy();
}
return(c);
}
static void sqlite3CodecGetKey(sqlite3 db, int nDb, out string zKey, out int nKey)
{
Db pDb = db.aDb[nDb];
CODEC_TRACE("sqlite3CodecGetKey: entered db=%d, nDb=%d\n", db, nDb);
if (pDb.pBt != null)
{
codec_ctx ctx = null;
sqlite3pager_get_codec(pDb.pBt.pBt.pPager, ref ctx);
if (ctx != null)
{ /* if the codec has an attached codec_context user the raw key data */
zKey = ctx.read_ctx.pass;
nKey = ctx.read_ctx.pass_sz;
return;
}
}
zKey = null;
nKey = 0;
}
static int codec_set_pass_key(sqlite3 db, int nDb, string zKey, int nKey, int for_ctx)
{
Db pDb = db.aDb[nDb];
CODEC_TRACE("codec_set_pass_key: entered db=%d nDb=%d cipher_name=%s nKey=%d for_ctx=%d\n", db, nDb, zKey, nKey, for_ctx);
if (pDb.pBt != null)
{
codec_ctx ctx = null;
cipher_ctx c_ctx;
sqlite3pager_get_codec(pDb.pBt.pBt.pPager, ref ctx);
c_ctx = for_ctx != 0 ? ctx.write_ctx : ctx.read_ctx;
cipher_ctx_set_pass(c_ctx, zKey, nKey);
c_ctx.derive_key = true;
if (for_ctx == 2)
{
cipher_ctx_copy(for_ctx != 0 ? ctx.read_ctx : ctx.write_ctx, c_ctx);
}
return(SQLITE_OK);
}
return(SQLITE_ERROR);
}
/**
*
* when for_ctx == 0 then it will change for read
* when for_ctx == 1 then it will change for write
* when for_ctx == 2 then it will change for both
*/
private static int codec_set_cipher_name(sqlite3 db, int nDb, string cipher_name, int for_ctx)
{
var pDb = db.aDb[nDb];
CODEC_TRACE("codec_set_cipher_name: entered db=%d nDb=%d cipher_name=%s for_ctx=%d\n", db, nDb, cipher_name, for_ctx);
if (pDb.pBt != null)
{
codec_ctx ctx = null;
cipher_ctx c_ctx;
sqlite3pager_get_codec(pDb.pBt.pBt.pPager, ref ctx);
c_ctx = for_ctx != 0 ? ctx.write_ctx : ctx.read_ctx;
c_ctx.derive_key = true;
if (for_ctx == 2)
{
cipher_ctx_copy(for_ctx != 0 ? ctx.read_ctx : ctx.write_ctx, c_ctx);
}
return(SQLITE_OK);
}
return(SQLITE_ERROR);
}
/* sqlite3_rekey
** Given a database, this will reencrypt the database using a new key.
** There are two possible modes of operation. The first is rekeying
** an existing database that was not previously encrypted. The second
** is to change the key on an existing database.
**
** The proposed logic for this function follows:
** 1. Determine if there is already a key present
** 2. If there is NOT already a key present, create one and attach a codec (key would be null)
** 3. Initialize a ctx.rekey parameter of the codec
**
** Note: this will require modifications to the sqlite3Codec to support rekey
**
*/
public static int sqlite3_rekey(sqlite3 db, string pKey, int nKey)
{
CODEC_TRACE("sqlite3_rekey: entered db=%d pKey=%s, nKey=%d\n", db, pKey, nKey);
//activate_openssl();
if (db != null && pKey != null)
{
Db pDb = db.aDb[0];
CODEC_TRACE("sqlite3_rekey: database pDb=%d\n", pDb);
if (pDb.pBt != null)
{
codec_ctx ctx = null;
int rc;
Pgno page_count = 0;
Pgno pgno;
PgHdr page = null;
Pager pPager = pDb.pBt.pBt.pPager;
sqlite3pager_get_codec(pDb.pBt.pBt.pPager, ref ctx);
if (ctx == null)
{
CODEC_TRACE("sqlite3_rekey: no codec attached to db, attaching now\n");
/* there was no codec attached to this database,so attach one now with a null password */
sqlite3CodecAttach(db, 0, pKey, nKey);
sqlite3pager_get_codec(pDb.pBt.pBt.pPager, ref ctx);
/* prepare this setup as if it had already been initialized */
Buffer.BlockCopy(Encoding.UTF8.GetBytes(SQLITE_FILE_HEADER), 0, ctx.read_ctx.iv, 0, FILE_HEADER_SZ);
ctx.read_ctx.key_sz = ctx.read_ctx.iv_sz = ctx.read_ctx.pass_sz = 0;
}
//if ( ctx.read_ctx.iv_sz != ctx.write_ctx.iv_sz )
//{
// string error = "";
// CODEC_TRACE( "sqlite3_rekey: updating page size for iv_sz change from %d to %d\n", ctx.read_ctx.iv_sz, ctx.write_ctx.iv_sz );
// db.nextPagesize = sqlite3BtreeGetPageSize( pDb.pBt );
// pDb.pBt.pBt.pageSizeFixed = false; /* required for sqlite3BtreeSetPageSize to modify pagesize setting */
// sqlite3BtreeSetPageSize( pDb.pBt, db.nextPagesize, MAX_IV_LENGTH, 0 );
// sqlite3RunVacuum( ref error, db );
//}
codec_set_pass_key(db, 0, pKey, nKey, 1);
ctx.mode_rekey = 1;
/* do stuff here to rewrite the database
** 1. Create a transaction on the database
** 2. Iterate through each page, reading it and then writing it.
** 3. If that goes ok then commit and put ctx.rekey into ctx.key
** note: don't deallocate rekey since it may be used in a subsequent iteration
*/
rc = sqlite3BtreeBeginTrans(pDb.pBt, 1); /* begin write transaction */
sqlite3PagerPagecount(pPager, out page_count);
for (pgno = 1; rc == SQLITE_OK && pgno <= page_count; pgno++)
{ /* pgno's start at 1 see pager.c:pagerAcquire */
if (0 == sqlite3pager_is_mj_pgno(pPager, pgno))
{ /* skip this page (see pager.c:pagerAcquire for reasoning) */
rc = sqlite3PagerGet(pPager, pgno, ref page);
if (rc == SQLITE_OK)
{ /* write page see pager_incr_changecounter for example */
rc = sqlite3PagerWrite(page);
//printf("sqlite3PagerWrite(%d)\n", pgno);
if (rc == SQLITE_OK)
{
sqlite3PagerUnref(page);
}
}
}
}
/* if commit was successful commit and copy the rekey data to current key, else rollback to release locks */
if (rc == SQLITE_OK)
{
CODEC_TRACE("sqlite3_rekey: committing\n");
db.nextPagesize = sqlite3BtreeGetPageSize(pDb.pBt);
rc = sqlite3BtreeCommit(pDb.pBt);
if (ctx != null)
{
cipher_ctx_copy(ctx.read_ctx, ctx.write_ctx);
}
}
else
{
CODEC_TRACE("sqlite3_rekey: rollback\n");
sqlite3BtreeRollback(pDb.pBt);
}
ctx.mode_rekey = 0;
}
return(SQLITE_OK);
}
return(SQLITE_ERROR);
}
/*
** Set or retrieve the codec for this pager
*/
static void sqlite3PagerSetCodec(
Pager pPager,
dxCodec xCodec, //void *(*xCodec)(void*,void*,Pgno,int),
dxCodecSizeChng xCodecSizeChng, //void (*xCodecSizeChng)(void*,int,int),
dxCodecFree xCodecFree, //void (*xCodecFree)(void*),
codec_ctx pCodec
)
{
if ( pPager.xCodecFree != null ) pPager.xCodecFree( ref pPager.pCodec );
pPager.xCodec = (pPager.memDb!=0) ? null : xCodec;
pPager.xCodecSizeChng = xCodecSizeChng;
pPager.xCodecFree = xCodecFree;
pPager.pCodec = pCodec;
pagerReportSize( pPager );
}
public codec_ctx Copy( )
{
codec_ctx c = new codec_ctx();
c.mode_rekey = mode_rekey;
c.buffer = sqlite3MemMalloc( buffer.Length );
c.pBt = pBt;
if ( read_ctx != null ) c.read_ctx = read_ctx.Copy();
if ( write_ctx != null ) c.write_ctx = write_ctx.Copy();
return c;
}
/*
* sqlite3Codec can be called in multiple modes.
* encrypt mode - expected to return a pointer to the
* encrypted data without altering pData.
* decrypt mode - expected to return a pointer to pData, with
* the data decrypted in the input buffer
*/
static byte[] sqlite3Codec(codec_ctx iCtx, byte[] data, Pgno pgno, int mode)
{
codec_ctx ctx = (codec_ctx)iCtx;
int pg_sz = sqlite3BtreeGetPageSize(ctx.pBt);
int offset = 0;
byte[] pData = data;
CODEC_TRACE("sqlite3Codec: entered pgno=%d, mode=%d, ctx.mode_rekey=%d, pg_sz=%d\n", pgno, mode, ctx.mode_rekey, pg_sz);
/* derive key on first use if necessary */
if (ctx.read_ctx.derive_key)
{
codec_key_derive(ctx, ctx.read_ctx);
ctx.read_ctx.derive_key = false;
}
if (ctx.write_ctx.derive_key)
{
if (cipher_ctx_cmp(ctx.write_ctx, ctx.read_ctx) == 0)
{
cipher_ctx_copy(ctx.write_ctx, ctx.read_ctx); // the relevant parameters are the same, just copy read key
}
else
{
codec_key_derive(ctx, ctx.write_ctx);
ctx.write_ctx.derive_key = false;
}
}
CODEC_TRACE("sqlite3Codec: switch mode=%d offset=%d\n", mode, offset);
if (ctx.buffer.Length != pg_sz)
{
ctx.buffer = sqlite3MemMalloc(pg_sz);
}
switch (mode)
{
case SQLITE_DECRYPT:
codec_cipher(ctx.read_ctx, pgno, CIPHER_DECRYPT, pg_sz, pData, ctx.buffer);
if (pgno == 1)
{
Buffer.BlockCopy(Encoding.UTF8.GetBytes(SQLITE_FILE_HEADER), 0, ctx.buffer, 0, FILE_HEADER_SZ); // memcpy( ctx.buffer, SQLITE_FILE_HEADER, FILE_HEADER_SZ ); /* copy file header to the first 16 bytes of the page */
}
Buffer.BlockCopy(ctx.buffer, 0, pData, 0, pg_sz); //memcpy( pData, ctx.buffer, pg_sz ); /* copy buffer data back to pData and return */
return(pData);
case SQLITE_ENCRYPT_WRITE_CTX: /* encrypt */
if (pgno == 1)
{
Buffer.BlockCopy(ctx.write_ctx.iv, 0, ctx.buffer, 0, FILE_HEADER_SZ);//memcpy( ctx.buffer, ctx.iv, FILE_HEADER_SZ ); /* copy salt to output buffer */
}
codec_cipher(ctx.write_ctx, pgno, CIPHER_ENCRYPT, pg_sz, pData, ctx.buffer);
return(ctx.buffer); /* return persistent buffer data, pData remains intact */
case SQLITE_ENCRYPT_READ_CTX:
if (pgno == 1)
{
Buffer.BlockCopy(ctx.read_ctx.iv, 0, ctx.buffer, 0, FILE_HEADER_SZ);//memcpy( ctx.buffer, ctx.iv, FILE_HEADER_SZ ); /* copy salt to output buffer */
}
codec_cipher(ctx.read_ctx, pgno, CIPHER_ENCRYPT, pg_sz, pData, ctx.buffer);
return(ctx.buffer); /* return persistent buffer data, pData remains intact */
default:
return(pData);
}
}
static void sqlite3pager_sqlite3PagerSetCodec(
Pager pPager,
dxCodec xCodec,
dxCodecSizeChng xCodecSizeChng,
dxCodecFree xCodecFree,
codec_ctx pCodec
)
{
sqlite3PagerSetCodec( pPager, xCodec, xCodecSizeChng, xCodecFree, pCodec );
}
/* BEGIN CRYPTO */
static void sqlite3pager_get_codec( Pager pPager, ref codec_ctx ctx )
{
ctx = pPager.pCodec;
}
/* BEGIN CRYPTO */
static void sqlite3pager_get_codec(Pager pPager, ref codec_ctx ctx)
{
ctx = pPager.pCodec;
}
/**
* Free and wipe memory associated with a cipher_ctx, including the allocated
* read_ctx and write_ctx.
*/
static void codec_ctx_free( ref codec_ctx iCtx )
{
codec_ctx ctx = iCtx;
CODEC_TRACE( "codec_ctx_free: entered iCtx=%d\n", iCtx );
cipher_ctx_free( ref ctx.read_ctx );
cipher_ctx_free( ref ctx.write_ctx );
iCtx = new codec_ctx();//codec_free(ctx, sizeof(codec_ctx);
}
/**
* Derive an encryption key for a cipher contex key based on the raw password.
*
* If the raw key data is formated as x'hex' and there are exactly enough hex chars to fill
* the key space (i.e 64 hex chars for a 256 bit key) then the key data will be used directly.
*
* Otherwise, a key data will be derived using PBKDF2
*
* returns SQLITE_OK if initialization was successful
* returns SQLITE_NOMEM if the key could't be derived (for instance if pass is null or pass_sz is 0)
*/
static int codec_key_derive( codec_ctx ctx, cipher_ctx c_ctx )
{
CODEC_TRACE( "codec_key_derive: entered c_ctx.pass=%s, c_ctx.pass_sz=%d ctx.iv=%d ctx.iv_sz=%d c_ctx.kdf_iter=%d c_ctx.key_sz=%d\n",
c_ctx.pass, c_ctx.pass_sz, c_ctx.iv, c_ctx.iv_sz, c_ctx.key_sz );
if ( c_ctx.pass != null && c_ctx.pass_sz > 0 )
{ // if pass is not null
if ( ( c_ctx.pass_sz == ( c_ctx.key_sz * 2 ) + 3 ) && sqlite3StrNICmp( c_ctx.pass, "x'", 2 ) == 0 )
{
int n = c_ctx.pass_sz - 3; /* adjust for leading x' and tailing ' */
string z = c_ctx.pass.Substring( 2 );// + 2; /* adjust lead offset of x' */
CODEC_TRACE( "codec_key_derive: deriving key from hex\n" );
c_ctx.key = sqlite3HexToBlob( null, z, n);
}
else
{
CODEC_TRACE( "codec_key_derive: deriving key using AES256\n" );
Rfc2898DeriveBytes k1 = new Rfc2898DeriveBytes( c_ctx.pass, c_ctx.iv, 2010 );
c_ctx.key_sz = 32;
c_ctx.key = k1.GetBytes( c_ctx.key_sz );
}
c_ctx.encryptor = Aes.CreateEncryptor( c_ctx.key, c_ctx.iv );
c_ctx.decryptor = Aes.CreateDecryptor( c_ctx.key, c_ctx.iv );
return SQLITE_OK;
};
return SQLITE_ERROR;
}
/*
* sqlite3Codec can be called in multiple modes.
* encrypt mode - expected to return a pointer to the
* encrypted data without altering pData.
* decrypt mode - expected to return a pointer to pData, with
* the data decrypted in the input buffer
*/
static byte[] sqlite3Codec(codec_ctx iCtx, byte[] data, Pgno pgno, int mode)
{
codec_ctx ctx = (codec_ctx)iCtx;
int pg_sz = sqlite3BtreeGetPageSize(ctx.pBt);
int offset = 0;
byte[] pData = data;
CODEC_TRACE("sqlite3Codec: entered pgno=%d, mode=%d, ctx.mode_rekey=%d, pg_sz=%d\n", pgno, mode, ctx.mode_rekey, pg_sz);
/* derive key on first use if necessary */
if (ctx.read_ctx.derive_key)
{
codec_key_derive(ctx, ctx.read_ctx);
ctx.read_ctx.derive_key = false;
}
if (ctx.write_ctx.derive_key)
{
if (cipher_ctx_cmp(ctx.write_ctx, ctx.read_ctx) == 0)
{
cipher_ctx_copy(ctx.write_ctx, ctx.read_ctx); // the relevant parameters are the same, just copy read key
}
else
{
codec_key_derive(ctx, ctx.write_ctx);
ctx.write_ctx.derive_key = false;
}
}
// bug from csharp project port
// fix from original: https://github.com/sqlcipher/sqlcipher/blob/master/src/crypto.c
// original
// if(pgno == 1) offset = FILE_HEADER_SZ; /* adjust starting pointers in data page for header offset on first page*/
CODEC_TRACE("sqlite3Codec: switch mode=%d offset=%d\n", mode, offset);
if (ctx.buffer.Length != pg_sz)
{
ctx.buffer = sqlite3MemMalloc(pg_sz);
}
switch (mode)
{
case SQLITE_DECRYPT:
// original
// if(pgno == 1) memcpy(buffer, SQLITE_FILE_HEADER, FILE_HEADER_SZ); /* copy file header to the first 16 bytes of the page */
// rc = sqlcipher_page_cipher(ctx, CIPHER_READ_CTX, pgno, CIPHER_DECRYPT, page_sz - offset, pData + offset, (unsigned char*)buffer + offset);
// if(rc != SQLITE_OK) sqlcipher_codec_ctx_set_error(ctx, rc);
// memcpy(pData, buffer, page_sz); /* copy buffer data back to pData and return */
// return pData;
// c-sharp project
// codec_cipher( ctx.read_ctx, pgno, CIPHER_DECRYPT, pg_sz, pData, ctx.buffer );
// if ( pgno == 1 )
// Buffer.BlockCopy( Encoding.UTF8.GetBytes( SQLITE_FILE_HEADER ), 0, ctx.buffer, 0, FILE_HEADER_SZ );// memcpy( ctx.buffer, SQLITE_FILE_HEADER, FILE_HEADER_SZ ); /* copy file header to the first 16 bytes of the page */
// Buffer.BlockCopy( ctx.buffer, 0, pData, 0, pg_sz ); //memcpy( pData, ctx.buffer, pg_sz ); /* copy buffer data back to pData and return */
// return pData;
// my fix:
if (pgno == 1)
{
byte[] hdr = Encoding.UTF8.GetBytes(SQLITE_FILE_HEADER);
Buffer.BlockCopy(hdr, 0, ctx.buffer, 0, FILE_HEADER_SZ);// memcpy( ctx.buffer, SQLITE_FILE_HEADER, FILE_HEADER_SZ ); /* copy file header to the first 16 bytes of the page */
byte[] tmpOut = new byte[pg_sz - FILE_HEADER_SZ];
byte[] tmpData = new byte[pg_sz - FILE_HEADER_SZ];
Buffer.BlockCopy(pData, FILE_HEADER_SZ, tmpData, 0, pg_sz - FILE_HEADER_SZ);
codec_cipher(ctx.read_ctx, pgno, CIPHER_DECRYPT, pg_sz - FILE_HEADER_SZ, tmpData, tmpOut);
Buffer.BlockCopy(tmpOut, 0, ctx.buffer, FILE_HEADER_SZ, pg_sz - FILE_HEADER_SZ);
Buffer.BlockCopy(ctx.buffer, 0, pData, 0, pg_sz);
}
else
{
codec_cipher(ctx.read_ctx, pgno, CIPHER_DECRYPT, pg_sz, pData, ctx.buffer);
Buffer.BlockCopy(ctx.buffer, 0, pData, 0, pg_sz);
}
return(pData);
case SQLITE_ENCRYPT_WRITE_CTX: /* encrypt */
// original
// if(pgno == 1) memcpy(buffer, kdf_salt, FILE_HEADER_SZ); /* copy salt to output buffer */
// rc = sqlcipher_page_cipher(ctx, CIPHER_WRITE_CTX, pgno, CIPHER_ENCRYPT, page_sz - offset, pData + offset, (unsigned char*)buffer + offset);
// if(rc != SQLITE_OK) sqlcipher_codec_ctx_set_error(ctx, rc);
// return buffer; /* return persistent buffer data, pData remains intact */
// c-sharp project
// if ( pgno == 1 )
// Buffer.BlockCopy( ctx.write_ctx.iv, 0, ctx.buffer, 0, FILE_HEADER_SZ );//memcpy( ctx.buffer, ctx.iv, FILE_HEADER_SZ ); /* copy salt to output buffer */
// codec_cipher( ctx.write_ctx, pgno, CIPHER_ENCRYPT, pg_sz, pData, ctx.buffer );
// return ctx.buffer; /* return persistent buffer data, pData remains intact */
// my fix
if (pgno == 1)
{
Buffer.BlockCopy(ctx.write_ctx.iv, 0, ctx.buffer, 0, FILE_HEADER_SZ);//memcpy( ctx.buffer, ctx.iv, FILE_HEADER_SZ ); /* copy salt to output buffer */
byte[] tmpOut = new byte[pg_sz - FILE_HEADER_SZ];
byte[] tmpData = new byte[pg_sz - FILE_HEADER_SZ];
Buffer.BlockCopy(pData, FILE_HEADER_SZ, tmpData, 0, pg_sz - FILE_HEADER_SZ);
codec_cipher(ctx.write_ctx, pgno, CIPHER_ENCRYPT, pg_sz - FILE_HEADER_SZ, tmpData, tmpOut);
Buffer.BlockCopy(tmpOut, 0, ctx.buffer, FILE_HEADER_SZ, pg_sz - FILE_HEADER_SZ);
}
else
{
codec_cipher(ctx.write_ctx, pgno, CIPHER_ENCRYPT, pg_sz, pData, ctx.buffer);
}
return(ctx.buffer); /* return persistent buffer data, pData remains intact */
case SQLITE_ENCRYPT_READ_CTX:
// original
// if(pgno == 1) memcpy(buffer, kdf_salt, FILE_HEADER_SZ); /* copy salt to output buffer */
// rc = sqlcipher_page_cipher(ctx, CIPHER_READ_CTX, pgno, CIPHER_ENCRYPT, page_sz - offset, pData + offset, (unsigned char*)buffer + offset);
// if(rc != SQLITE_OK) sqlcipher_codec_ctx_set_error(ctx, rc);
// return buffer; /* return persistent buffer data, pData remains intact */
// c-sharp project
// if ( pgno == 1 )
// Buffer.BlockCopy( ctx.read_ctx.iv, 0, ctx.buffer, 0, FILE_HEADER_SZ );//memcpy( ctx.buffer, ctx.iv, FILE_HEADER_SZ ); /* copy salt to output buffer */
// codec_cipher( ctx.read_ctx, pgno, CIPHER_ENCRYPT, pg_sz, pData, ctx.buffer );
// return ctx.buffer; /* return persistent buffer data, pData remains intact */
// my fix
if (pgno == 1)
{
Buffer.BlockCopy(ctx.read_ctx.iv, 0, ctx.buffer, 0, FILE_HEADER_SZ);//memcpy( ctx.buffer, ctx.iv, FILE_HEADER_SZ ); /* copy salt to output buffer */
byte[] tmpOut = new byte[pg_sz - FILE_HEADER_SZ];
byte[] tmpData = new byte[pg_sz - FILE_HEADER_SZ];
Buffer.BlockCopy(pData, FILE_HEADER_SZ, tmpData, 0, pg_sz - FILE_HEADER_SZ);
codec_cipher(ctx.read_ctx, pgno, CIPHER_ENCRYPT, pg_sz - FILE_HEADER_SZ, tmpData, tmpOut);
Buffer.BlockCopy(tmpOut, 0, ctx.buffer, FILE_HEADER_SZ, pg_sz - FILE_HEADER_SZ);
}
else
{
codec_cipher(ctx.read_ctx, pgno, CIPHER_ENCRYPT, pg_sz, pData, ctx.buffer);
}
return(ctx.buffer); /* return persistent buffer data, pData remains intact */
default:
return(pData);
}
}
static void sqlite3FreeCodecArg( ref codec_ctx pCodecArg )
{
if ( pCodecArg == null ) return;
codec_ctx_free( ref pCodecArg ); // wipe and free allocated memory for the context
}
static int sqlite3CodecAttach( sqlite3 db, int nDb, string zKey, int nKey )
{
Db pDb = db.aDb[nDb];
CODEC_TRACE( "sqlite3CodecAttach: entered nDb=%d zKey=%s, nKey=%d\n", nDb, zKey, nKey );
//activate_openssl();
if ( zKey != null && pDb.pBt != null )
{
Aes.KeySize = 256;
#if !SQLITE_SILVERLIGHT
Aes.Padding = PaddingMode.None;
#endif
codec_ctx ctx;
int rc;
Pager pPager = pDb.pBt.pBt.pPager;
sqlite3_file fd;
ctx = new codec_ctx();//sqlite3Malloc(sizeof(codec_ctx);
//if(ctx == null) return SQLITE_NOMEM;
//memset(ctx, 0, sizeof(codec_ctx); /* initialize all pointers and values to 0 */
ctx.pBt = pDb.pBt; /* assign pointer to database btree structure */
if ( ( rc = cipher_ctx_init( ref ctx.read_ctx ) ) != SQLITE_OK ) return rc;
if ( ( rc = cipher_ctx_init( ref ctx.write_ctx ) ) != SQLITE_OK ) return rc;
/* pre-allocate a page buffer of PageSize bytes. This will
be used as a persistent buffer for encryption and decryption
operations to avoid overhead of multiple memory allocations*/
ctx.buffer = sqlite3MemMalloc(sqlite3BtreeGetPageSize( ctx.pBt ));//sqlite3Malloc(sqlite3BtreeGetPageSize(ctx.pBt);
//if(ctx.buffer == null) return SQLITE_NOMEM;
/* allocate space for salt data. Then read the first 16 bytes header as the salt for the key derivation */
ctx.read_ctx.iv_sz = FILE_HEADER_SZ;
ctx.read_ctx.iv = new byte[ctx.read_ctx.iv_sz];//sqlite3Malloc( ctx.iv_sz );
Buffer.BlockCopy( Encoding.UTF8.GetBytes( SQLITE_FILE_HEADER ), 0, ctx.read_ctx.iv, 0, FILE_HEADER_SZ );
sqlite3pager_sqlite3PagerSetCodec( sqlite3BtreePager( pDb.pBt ), sqlite3Codec, null, sqlite3FreeCodecArg, ctx );
codec_set_cipher_name( db, nDb, CIPHER, 0 );
codec_set_pass_key( db, nDb, zKey, nKey, 0 );
cipher_ctx_copy( ctx.write_ctx, ctx.read_ctx );
//sqlite3BtreeSetPageSize( ctx.pBt, sqlite3BtreeGetPageSize( ctx.pBt ), MAX_IV_LENGTH, 0 );
}
return SQLITE_OK;
}
/*
* sqlite3Codec can be called in multiple modes.
* encrypt mode - expected to return a pointer to the
* encrypted data without altering pData.
* decrypt mode - expected to return a pointer to pData, with
* the data decrypted in the input buffer
*/
static byte[] sqlite3Codec( codec_ctx iCtx, byte[] data, Pgno pgno, int mode )
{
codec_ctx ctx = (codec_ctx)iCtx;
int pg_sz = sqlite3BtreeGetPageSize( ctx.pBt );
int offset = 0;
byte[] pData = data;
CODEC_TRACE( "sqlite3Codec: entered pgno=%d, mode=%d, ctx.mode_rekey=%d, pg_sz=%d\n", pgno, mode, ctx.mode_rekey, pg_sz );
/* derive key on first use if necessary */
if ( ctx.read_ctx.derive_key )
{
codec_key_derive( ctx, ctx.read_ctx );
ctx.read_ctx.derive_key = false;
}
if ( ctx.write_ctx.derive_key )
{
if ( cipher_ctx_cmp( ctx.write_ctx, ctx.read_ctx ) == 0 )
{
cipher_ctx_copy( ctx.write_ctx, ctx.read_ctx ); // the relevant parameters are the same, just copy read key
}
else
{
codec_key_derive( ctx, ctx.write_ctx );
ctx.write_ctx.derive_key = false;
}
}
CODEC_TRACE( "sqlite3Codec: switch mode=%d offset=%d\n", mode, offset );
if ( ctx.buffer.Length != pg_sz ) ctx.buffer = sqlite3MemMalloc(pg_sz);
switch ( mode )
{
case SQLITE_DECRYPT:
codec_cipher( ctx.read_ctx, pgno, CIPHER_DECRYPT, pg_sz, pData, ctx.buffer);
if ( pgno == 1 ) Buffer.BlockCopy( Encoding.UTF8.GetBytes( SQLITE_FILE_HEADER ), 0, ctx.buffer, 0, FILE_HEADER_SZ );// memcpy( ctx.buffer, SQLITE_FILE_HEADER, FILE_HEADER_SZ ); /* copy file header to the first 16 bytes of the page */
Buffer.BlockCopy( ctx.buffer, 0, pData, 0, pg_sz ); //memcpy( pData, ctx.buffer, pg_sz ); /* copy buffer data back to pData and return */
return pData;
case SQLITE_ENCRYPT_WRITE_CTX: /* encrypt */
if ( pgno == 1 ) Buffer.BlockCopy( ctx.write_ctx.iv, 0, ctx.buffer, 0, FILE_HEADER_SZ );//memcpy( ctx.buffer, ctx.iv, FILE_HEADER_SZ ); /* copy salt to output buffer */
codec_cipher( ctx.write_ctx, pgno, CIPHER_ENCRYPT, pg_sz, pData, ctx.buffer);
return ctx.buffer; /* return persistent buffer data, pData remains intact */
case SQLITE_ENCRYPT_READ_CTX:
if ( pgno == 1 ) Buffer.BlockCopy( ctx.read_ctx.iv, 0, ctx.buffer, 0, FILE_HEADER_SZ );//memcpy( ctx.buffer, ctx.iv, FILE_HEADER_SZ ); /* copy salt to output buffer */
codec_cipher( ctx.read_ctx, pgno, CIPHER_ENCRYPT, pg_sz, pData, ctx.buffer);
return ctx.buffer; /* return persistent buffer data, pData remains intact */
default:
return pData;
}
}
