On Fri 10 Feb 2017 06:09:05 PM CET, Daniel P. Berrange wrote:
> @@ -990,12 +1123,6 @@ static int qcow2_open(BlockDriverState *bs, QDict
> *options, int flags,
> s->refcount_max = UINT64_C(1) << (s->refcount_bits - 1);
> s->refcount_max += s->refcount_max - 1;
>
> - if (header.crypt_method > QCOW_CRYPT_AES) {
> - error_setg(errp, "Unsupported encryption method: %" PRIu32,
> - header.crypt_method);
> - ret = -EINVAL;
> - goto fail;
> - }
Here you remove the check for a valid encryption method...
> s->crypt_method_header = header.crypt_method;
> if (s->crypt_method_header) {
> if (bdrv_uses_whitelist() &&
> @@ -1012,6 +1139,12 @@ static int qcow2_open(BlockDriverState *bs, QDict
> *options, int flags,
> goto fail;
> }
>
> + if (s->crypt_method_header == QCOW_CRYPT_AES) {
> + s->crypt_physical_offset = false;
> + } else {
> + s->crypt_physical_offset = true;
> + }
> +
...and here you assume that if it's not AES then it must be LUKS.
However at this point crypt_method_header hasn't been verified yet and
can have any value.
The image will fail to open anyway because of the qcow2_update_options()
call later in this function, but I think it wouldn't hurt to have an
explicit check here, or at least an explanatory comment.
> +static int qcow2_crypt_method_from_format(const char *format)
> +{
> + if (g_str_equal(format, "luks")) {
> + return QCOW_CRYPT_LUKS;
> + } else if (g_str_equal(format, "aes")) {
> + return QCOW_CRYPT_AES;
> + } else {
> + return -EINVAL;
> + }
> +}
>
> static int qcow2_set_up_encryption(BlockDriverState *bs, QemuOpts *opts,
> - Error **errp)
> + const char *format, Error **errp)
> {
> BDRVQcow2State *s = bs->opaque;
> QCryptoBlockCreateOptions *cryptoopts = NULL;
> QCryptoBlock *crypto = NULL;
> int ret = -EINVAL;
>
> - cryptoopts = block_crypto_create_opts_init(
> - Q_CRYPTO_BLOCK_FORMAT_QCOW, opts, "aes-", errp);
> + if (g_str_equal(format, "luks")) {
> + cryptoopts = block_crypto_create_opts_init(
> + Q_CRYPTO_BLOCK_FORMAT_LUKS, opts, "luks-", errp);
> + s->crypt_method_header = QCOW_CRYPT_LUKS;
> + } else if (g_str_equal(format, "aes")) {
> + cryptoopts = block_crypto_create_opts_init(
> + Q_CRYPTO_BLOCK_FORMAT_QCOW, opts, "aes-", errp);
> + s->crypt_method_header = QCOW_CRYPT_AES;
> + } else {
You just added a nice qcow2_crypt_method_from_format() function
immediately before this one, I think this one would be more readable if
you use it here.
Berto
