void sqliterkCryptoFreeCodec(sqliterk_pager *pager)
{
if (!pager->codec)
return;
sqlcipher_codec_ctx_free(&pager->codec);
sqlcipher_deactivate();
}
void sqlite3FreeCodecArg(void *pCodecArg) {
codec_ctx *ctx = (codec_ctx *) pCodecArg;
if(pCodecArg == NULL) return;
sqlcipher_codec_ctx_free(&ctx); // wipe and free allocated memory for the context
sqlcipher_deactivate(); /* cleanup related structures, OpenSSL etc, when codec is detatched */
}
int sqliterkCryptoSetCipher(sqliterk_pager *pager,
sqliterk_file *fd,
const sqliterk_cipher_conf *conf)
{
codec_ctx *codec = NULL;
int rc;
if (conf) {
// Check arguments.
if (!conf->key || conf->key_len <= 0)
return SQLITERK_MISUSE;
// SQLite library must be initialized before calling sqlcipher_activate(),
// or it will cause a deadlock.
sqlite3_initialize();
sqlcipher_activate();
// XXX: fake BTree structure passed to sqlcipher_codec_ctx_init.
// Member of such structure is assigned but never used by repair kit.
int fake_db[8];
sqlite3_file_rkredir file;
struct sqlite3_io_methods methods = {0};
methods.xRead = sqliterkRead;
file.pMethods = &methods;
file.fd = fd;
file.kdf_salt = conf->kdf_salt;
// Initialize codec context.
rc = sqlcipher_codec_ctx_init(&codec, fake_db, NULL, &file, conf->key,
conf->key_len);
if (rc != SQLITE_OK)
goto bail_sqlite_errstr;
// Set cipher.
if (conf->cipher_name) {
rc = sqlcipher_codec_ctx_set_cipher(codec, conf->cipher_name,
CIPHER_READWRITE_CTX);
if (rc != SQLITE_OK)
goto bail_sqlite_errstr;
}
// Set page size.
if (conf->page_size > 0) {
rc = sqlcipher_codec_ctx_set_pagesize(codec, conf->page_size);
if (rc != SQLITE_OK)
goto bail_sqlite_errstr;
}
// Set HMAC usage.
if (conf->use_hmac >= 0) {
rc = sqlcipher_codec_ctx_set_use_hmac(codec, conf->use_hmac);
if (rc != SQLITE_OK)
goto bail_sqlite_errstr;
}
// Set KDF Iteration.
if (conf->kdf_iter > 0) {
rc = sqlcipher_codec_ctx_set_kdf_iter(codec, conf->kdf_iter,
CIPHER_READWRITE_CTX);
if (rc != SQLITE_OK)
goto bail;
}
// Update pager page size.
int page_sz = sqlcipher_codec_ctx_get_pagesize(codec);
int reserve_sz = sqlcipher_codec_ctx_get_reservesize(codec);
pager->pagesize = page_sz;
pager->reservedBytes = reserve_sz;
}
if (pager->codec) {
sqlcipher_codec_ctx_free(&pager->codec);
sqlcipher_deactivate();
}
pager->codec = codec;
return SQLITERK_OK;
bail_sqlite_errstr:
sqliterkOSError(SQLITERK_CANTOPEN,
"Failed to initialize cipher context: %s",
sqlite3_errstr(rc));
rc = SQLITERK_CANTOPEN;
bail:
if (codec)
sqlcipher_codec_ctx_free(&codec);
sqlcipher_deactivate();
return rc;
}
