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[Qemu-block] [PATCH v2 09/13] qcrypto-block: extract check and parse hea
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From: |
Maxim Levitsky |
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Subject: |
[Qemu-block] [PATCH v2 09/13] qcrypto-block: extract check and parse header |
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Date: |
Mon, 26 Aug 2019 16:50:59 +0300 |
This is just to make qcrypto_block_luks_open more
reasonable in size.
Signed-off-by: Maxim Levitsky <address@hidden>
---
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
+ *
+ * <cipher-mode>-<iv-generator>[:<iv-hash>]
+ *
+ * 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;
- 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;
- 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;
- }
-
- cipher_mode = g_strdup(luks->header.cipher_mode);
-
- /*
- * 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;
- error_setg(errp, "Unexpected cipher mode string format %s",
- cipher_mode);
- goto fail;
- }
- *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 fail;
- }
- }
-
- luks->cipher_mode = qcrypto_block_luks_cipher_mode_lookup(cipher_mode,
- &local_err);
- if (local_err) {
- ret = -ENOTSUP;
- error_propagate(errp, local_err);
- goto fail;
- }
-
- 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 fail;
- }
-
- 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);
+ ret = qcrypto_block_luks_check_header(luks, errp);
+ if (ret) {
goto fail;
}
- luks->ivgen_alg = qcrypto_block_luks_ivgen_name_lookup(ivgen_name,
- &local_err);
- if (local_err) {
- ret = -ENOTSUP;
- error_propagate(errp, local_err);
+ ret = qcrypto_block_luks_parse_header(luks, errp);
+ if (ret) {
goto fail;
}
- if (luks->ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) {
- if (!ivhash_name) {
- ret = -EINVAL;
- error_setg(errp, "Missing IV generator hash specification");
- goto fail;
- }
- 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 fail;
- }
- } 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;
- }
if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) {
/* Try to find which key slot our password is valid for
--
2.17.2
- Re: [Qemu-block] [Qemu-devel] [PATCH v2 01/13] introduce g_autowipe, (continued)
- [Qemu-block] [PATCH v2 02/13] block-crypto: misc refactoring, Maxim Levitsky, 2019/08/26
- [Qemu-block] [PATCH v2 03/13] qcrypto-luks: rename some fields in QCryptoBlockLUKSHeader, Maxim Levitsky, 2019/08/26
- [Qemu-block] [PATCH v2 04/13] qcrypto-luks: don't overwrite cipher_mode in header, Maxim Levitsky, 2019/08/26
- [Qemu-block] [PATCH v2 05/13] qcrypto-luks: simplify masterkey and masterkey length, Maxim Levitsky, 2019/08/26
- [Qemu-block] [PATCH v2 06/13] qcrypto-block: pass keyslot index rather that pointer to the keyslot, Maxim Levitsky, 2019/08/26
- [Qemu-block] [PATCH v2 07/13] qcrypto-luks: use the parsed encryption settings in QCryptoBlockLUKS, Maxim Levitsky, 2019/08/26
- [Qemu-block] [PATCH v2 08/13] qcrypto-luks: extract store and load header, Maxim Levitsky, 2019/08/26
- [Qemu-block] [PATCH v2 09/13] qcrypto-block: extract check and parse header,
Maxim Levitsky <=
- [Qemu-block] [PATCH v2 10/13] qcrypto-luks: refactoring: extract store key function, Maxim Levitsky, 2019/08/26
- [Qemu-block] [PATCH v2 11/13] qcrypto-luks: refactoring: simplify the math used for keyslot locations, Maxim Levitsky, 2019/08/26
- [Qemu-block] [PATCH v2 12/13] qcrypto-luks: use g_autowipe, Maxim Levitsky, 2019/08/26
- [Qemu-block] [PATCH v2 13/13] qcrypto-luks: implement more rigorous header checking, Maxim Levitsky, 2019/08/26