On Mon, Aug 26, 2019 at 04:50:59PM +0300, Maxim Levitsky wrote:
> This is just to make qcrypto_block_luks_open more
> reasonable in size.
>
> Signed-off-by: Maxim Levitsky <mlevi...@redhat.com>
> ---
> crypto/block-luks.c | 254 +++++++++++++++++++++++++-------------------
> 1 file changed, 146 insertions(+), 108 deletions(-)
>
> diff --git a/crypto/block-luks.c b/crypto/block-luks.c
> index b4dc6fc899..cc9a52c9af 100644
> --- a/crypto/block-luks.c
> +++ b/crypto/block-luks.c
> @@ -508,6 +508,148 @@ fail:
> return ret;
> }
>
> +/*
> + * Does basic sanity checks on the LUKS header
> + */
> +static int
> +qcrypto_block_luks_check_header(const QCryptoBlockLUKS *luks, Error **errp)
> +{
> + int ret;
> +
> + if (memcmp(luks->header.magic, qcrypto_block_luks_magic,
> + QCRYPTO_BLOCK_LUKS_MAGIC_LEN) != 0) {
> + error_setg(errp, "Volume is not in LUKS format");
> + ret = -EINVAL;
> + goto fail;
> + }
Just 'return -1' here immediately - don't return an errno, as we're
using Error objects for reporting.
> +
> + if (luks->header.version != QCRYPTO_BLOCK_LUKS_VERSION) {
> + error_setg(errp, "LUKS version %" PRIu32 " is not supported",
> + luks->header.version);
> + ret = -ENOTSUP;
> + goto fail;
> + }
> +
> + return 0;
> +fail:
> + return ret;
> +}
> +
> +/*
> + * Parses the crypto parameters that are stored in the LUKS header
> + */
> +
> +static int
> +qcrypto_block_luks_parse_header(QCryptoBlockLUKS *luks, Error **errp)
> +{
> + g_autofree char *cipher_mode = g_strdup(luks->header.cipher_mode);
> + char *ivgen_name, *ivhash_name;
> + int ret = -1;
> + Error *local_err = NULL;
> +
> + /*
> + * The cipher_mode header contains a string that we have
> + * to further parse, of the format
> + *
> + * <cipher-mode>-<iv-generator>[:<iv-hash>]
> + *
> + * eg cbc-essiv:sha256, cbc-plain64
> + */
> + ivgen_name = strchr(cipher_mode, '-');
> + if (!ivgen_name) {
> + ret = -EINVAL;
Again, don't use errnos - just return -1 in this method.
> + error_setg(errp, "Unexpected cipher mode string format %s",
> + luks->header.cipher_mode);
> + goto out;
> + }
> + *ivgen_name = '\0';
> + ivgen_name++;
> +
> + ivhash_name = strchr(ivgen_name, ':');
> + if (!ivhash_name) {
> + luks->ivgen_hash_alg = 0;
> + } else {
> + *ivhash_name = '\0';
> + ivhash_name++;
> +
> + luks->ivgen_hash_alg =
> qcrypto_block_luks_hash_name_lookup(ivhash_name,
> +
> &local_err);
> + if (local_err) {
> + ret = -ENOTSUP;
> + error_propagate(errp, local_err);
> + goto out;
> + }
> + }
> +
> + luks->cipher_mode = qcrypto_block_luks_cipher_mode_lookup(cipher_mode,
> + &local_err);
> + if (local_err) {
> + ret = -ENOTSUP;
> + error_propagate(errp, local_err);
> + goto out;
> + }
> +
> + luks->cipher_alg =
> + qcrypto_block_luks_cipher_name_lookup(luks->header.cipher_name,
> + luks->cipher_mode,
> +
> luks->header.master_key_len,
> + &local_err);
> + if (local_err) {
> + ret = -ENOTSUP;
> + error_propagate(errp, local_err);
> + goto out;
> + }
> +
> + luks->hash_alg =
> + qcrypto_block_luks_hash_name_lookup(luks->header.hash_spec,
> + &local_err);
> + if (local_err) {
> + ret = -ENOTSUP;
> + error_propagate(errp, local_err);
> + goto out;
> + }
> +
> + luks->ivgen_alg = qcrypto_block_luks_ivgen_name_lookup(ivgen_name,
> + &local_err);
> + if (local_err) {
> + ret = -ENOTSUP;
> + error_propagate(errp, local_err);
> + goto out;
> + }
> +
> + if (luks->ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) {
> + if (!ivhash_name) {
> + ret = -EINVAL;
> + error_setg(errp, "Missing IV generator hash specification");
> + goto out;
> + }
> + luks->ivgen_cipher_alg =
> + qcrypto_block_luks_essiv_cipher(luks->cipher_alg,
> + luks->ivgen_hash_alg,
> + &local_err);
> + if (local_err) {
> + ret = -ENOTSUP;
> + error_propagate(errp, local_err);
> + goto out;
> + }
> + } else {
> +
> + /*
> + * Note we parsed the ivhash_name earlier in the cipher_mode
> + * spec string even with plain/plain64 ivgens, but we
> + * will ignore it, since it is irrelevant for these ivgens.
> + * This is for compat with dm-crypt which will silently
> + * ignore hash names with these ivgens rather than report
> + * an error about the invalid usage
> + */
> + luks->ivgen_cipher_alg = luks->cipher_alg;
> + }
> + ret = 0;
> +out:
> + return ret;
> +
> +}
> +
> /*
> * Given a key slot, and user password, this will attempt to unlock
> * the master encryption key from the key slot.
> @@ -720,12 +862,9 @@ qcrypto_block_luks_open(QCryptoBlock *block,
> Error **errp)
> {
> QCryptoBlockLUKS *luks = NULL;
> - Error *local_err = NULL;
> int ret = 0;
> g_autofree uint8_t *masterkey = NULL;
> - char *ivgen_name, *ivhash_name;
> g_autofree char *password = NULL;
> - g_autofree char *cipher_mode = NULL;
>
> if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) {
> if (!options->u.luks.key_secret) {
> @@ -748,117 +887,16 @@ qcrypto_block_luks_open(QCryptoBlock *block,
> goto fail;
> }
>
> -
> - if (memcmp(luks->header.magic, qcrypto_block_luks_magic,
> - QCRYPTO_BLOCK_LUKS_MAGIC_LEN) != 0) {
> - error_setg(errp, "Volume is not in LUKS format");
> - ret = -EINVAL;
I can't remember why I set ret to an errno in my original code.
it is entirely pointless, as the caller of this method merely
checks "ret < 0" and doesn't do anything else with the return
value. IOW, we should just purge the errnors from this existing
code entirely.
Regards,
Daniel
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