Re: [Qemu-block] [PATCH v2 09/13] qcrypto-block: extract check and parse header
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
> ---
> 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
> + *
> + *-[:]
> + *
> + * 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
[Qemu-block] [PATCH v2 09/13] qcrypto-block: extract check and parse header
This is just to make qcrypto_block_luks_open more
reasonable in size.
Signed-off-by: Maxim Levitsky
---
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;
+}
+
+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
+ *
+ *-[:]
+ *
+ * eg cbc-essiv:sha256, cbc-plain64
+ */
+ivgen_name = strchr(cipher_mode, '-');
+if (!ivgen_name) {
+ret = -EINVAL;
+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;
-Err
