Switch the qcow/qcow2 block driver over to use the generic cipher
API, this allows it to use the pluggable AES implementations,
instead of being hardcoded to use QEMU's built-in impl.
Signed-off-by: Daniel P. Berrange <berra...@redhat.com>
---
block/qcow.c | 102 +++++++++++++++++++++++++++++++++++++-------------
block/qcow2-cluster.c | 46 ++++++++++++++++++-----
block/qcow2.c | 95 +++++++++++++++++++++++-----------------------
block/qcow2.h | 13 +++----
4 files changed, 165 insertions(+), 91 deletions(-)
diff --git a/block/qcow.c b/block/qcow.c
index 5a7c6cb..1e5179a 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -25,7 +25,7 @@
#include "block/block_int.h"
#include "qemu/module.h"
#include <zlib.h>
-#include "crypto/aes.h"
+#include "crypto/cipher.h"
#include "migration/migration.h"
/**************************************************************/
@@ -71,10 +71,8 @@ typedef struct BDRVQcowState {
uint8_t *cluster_cache;
uint8_t *cluster_data;
uint64_t cluster_cache_offset;
- uint32_t crypt_method; /* current crypt method, 0 if no key yet */
+ QCryptoCipher *cipher; /* NULL if no key yet */
uint32_t crypt_method_header;
- AES_KEY aes_encrypt_key;
- AES_KEY aes_decrypt_key;
CoMutex lock;
Error *migration_blocker;
} BDRVQcowState;
@@ -153,6 +151,11 @@ static int qcow_open(BlockDriverState *bs, QDict *options,
int flags,
ret = -EINVAL;
goto fail;
}
+ if (!qcrypto_cipher_supports(QCRYPTO_CIPHER_ALG_AES_128)) {
+ error_setg(errp, "AES cipher not available");
+ ret = -EINVAL;
+ goto fail;
+ }
s->crypt_method_header = header.crypt_method;
if (s->crypt_method_header) {
bs->encrypted = 1;
@@ -259,6 +262,7 @@ static int qcow_set_key(BlockDriverState *bs, const char
*key)
BDRVQcowState *s = bs->opaque;
uint8_t keybuf[16];
int len, i;
+ Error *err;
memset(keybuf, 0, 16);
len = strlen(key);
@@ -270,38 +274,67 @@ static int qcow_set_key(BlockDriverState *bs, const char
*key)
keybuf[i] = key[i];
}
assert(bs->encrypted);
- s->crypt_method = s->crypt_method_header;
- if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0)
- return -1;
- if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0)
+ qcrypto_cipher_free(s->cipher);
+ s->cipher = qcrypto_cipher_new(
+ QCRYPTO_CIPHER_ALG_AES_128,
+ QCRYPTO_CIPHER_MODE_CBC,
+ keybuf, G_N_ELEMENTS(keybuf),
+ &err);
+
+ if (!s->cipher) {
+ /* XXX would be nice if errors in this method could
+ * be properly propagate to the caller. Would need
+ * the bdrv_set_key() API signature to be fixed. */
+ error_free(err);
return -1;
+ }
return 0;
}
/* The crypt function is compatible with the linux cryptoloop
algorithm for < 4 GB images. NOTE: out_buf == in_buf is
supported */
-static void encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
- uint8_t *out_buf, const uint8_t *in_buf,
- int nb_sectors, int enc,
- const AES_KEY *key)
+static int encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
+ uint8_t *out_buf, const uint8_t *in_buf,
+ int nb_sectors, bool enc, Error **errp)
{
union {
uint64_t ll[2];
uint8_t b[16];
} ivec;
int i;
+ int ret;
for(i = 0; i < nb_sectors; i++) {
ivec.ll[0] = cpu_to_le64(sector_num);
ivec.ll[1] = 0;
- AES_cbc_encrypt(in_buf, out_buf, 512, key,
- ivec.b, enc);
+ if (qcrypto_cipher_setiv(s->cipher,
+ ivec.b, G_N_ELEMENTS(ivec.b),
+ errp) < 0) {
+ return -1;
+ }
+ if (enc) {
+ ret = qcrypto_cipher_encrypt(s->cipher,
+ in_buf,
+ out_buf,
+ 512,
+ errp);
+ } else {
+ ret = qcrypto_cipher_decrypt(s->cipher,
+ in_buf,
+ out_buf,
+ 512,
+ errp);
+ }
+ if (ret < 0) {
+ return -1;
+ }
sector_num++;
in_buf += 512;
out_buf += 512;
}
+ return 0;
}
/* 'allocate' is:
@@ -415,15 +448,20 @@ static uint64_t get_cluster_offset(BlockDriverState *bs,
if (bs->encrypted &&
(n_end - n_start) < s->cluster_sectors) {
uint64_t start_sect;
- assert(s->crypt_method);
+ assert(s->cipher);
start_sect = (offset & ~(s->cluster_size - 1)) >> 9;
memset(s->cluster_data + 512, 0x00, 512);
for(i = 0; i < s->cluster_sectors; i++) {
if (i < n_start || i >= n_end) {
- encrypt_sectors(s, start_sect + i,
- s->cluster_data,
- s->cluster_data + 512, 1, 1,
- &s->aes_encrypt_key);
+ Error *err = NULL;
+ if (encrypt_sectors(s, start_sect + i,
+ s->cluster_data,
+ s->cluster_data + 512, 1,
+ true, &err) < 0) {
+ error_free(err);
+ errno = EIO;
+ return -1;
+ }
if (bdrv_pwrite(bs->file, cluster_offset + i * 512,
s->cluster_data, 512) != 512)
return -1;
@@ -463,7 +501,7 @@ static int64_t coroutine_fn
qcow_co_get_block_status(BlockDriverState *bs,
if (!cluster_offset) {
return 0;
}
- if ((cluster_offset & QCOW_OFLAG_COMPRESSED) || s->crypt_method) {
+ if ((cluster_offset & QCOW_OFLAG_COMPRESSED) || s->cipher) {
return BDRV_BLOCK_DATA;
}
cluster_offset |= (index_in_cluster << BDRV_SECTOR_BITS);
@@ -530,6 +568,7 @@ static coroutine_fn int qcow_co_readv(BlockDriverState *bs,
int64_t sector_num,
QEMUIOVector hd_qiov;
uint8_t *buf;
void *orig_buf;
+ Error *err = NULL;
if (qiov->niov > 1) {
buf = orig_buf = qemu_try_blockalign(bs, qiov->size);
@@ -593,10 +632,11 @@ static coroutine_fn int qcow_co_readv(BlockDriverState
*bs, int64_t sector_num,
break;
}
if (bs->encrypted) {
- assert(s->crypt_method);
- encrypt_sectors(s, sector_num, buf, buf,
- n, 0,
- &s->aes_decrypt_key);
+ assert(s->cipher);
+ if (encrypt_sectors(s, sector_num, buf, buf,
+ n, false, &err) < 0) {
+ goto fail;
+ }
}
}
ret = 0;
@@ -617,6 +657,7 @@ done:
return ret;
fail:
+ error_free(err);
ret = -EIO;
goto done;
}
@@ -665,12 +706,17 @@ static coroutine_fn int qcow_co_writev(BlockDriverState
*bs, int64_t sector_num,
break;
}
if (bs->encrypted) {
- assert(s->crypt_method);
+ Error *err = NULL;
+ assert(s->cipher);
if (!cluster_data) {
cluster_data = g_malloc0(s->cluster_size);
}
- encrypt_sectors(s, sector_num, cluster_data, buf,
- n, 1, &s->aes_encrypt_key);
+ if (encrypt_sectors(s, sector_num, cluster_data, buf,
+ n, true, &err) < 0) {
+ error_free(err);
+ ret = -EIO;
+ break;
+ }
src_buf = cluster_data;
} else {
src_buf = buf;
@@ -707,6 +753,8 @@ static void qcow_close(BlockDriverState *bs)
{
BDRVQcowState *s = bs->opaque;
+ qcrypto_cipher_free(s->cipher);
+ s->cipher = NULL;
g_free(s->l1_table);
qemu_vfree(s->l2_cache);
g_free(s->cluster_cache);
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 1a5c97a..b43f186 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -339,26 +339,47 @@ static int count_contiguous_free_clusters(uint64_t
nb_clusters, uint64_t *l2_tab
/* The crypt function is compatible with the linux cryptoloop
algorithm for < 4 GB images. NOTE: out_buf == in_buf is
supported */
-void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
- uint8_t *out_buf, const uint8_t *in_buf,
- int nb_sectors, int enc,
- const AES_KEY *key)
+int qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
+ uint8_t *out_buf, const uint8_t *in_buf,
+ int nb_sectors, bool enc,
+ Error **errp)
{
union {
uint64_t ll[2];
uint8_t b[16];
} ivec;
int i;
+ int ret;
for(i = 0; i < nb_sectors; i++) {
ivec.ll[0] = cpu_to_le64(sector_num);
ivec.ll[1] = 0;
- AES_cbc_encrypt(in_buf, out_buf, 512, key,
- ivec.b, enc);
+ if (qcrypto_cipher_setiv(s->cipher,
+ ivec.b, G_N_ELEMENTS(ivec.b),
+ errp) < 0) {
+ return -1;
+ }
+ if (enc) {
+ ret = qcrypto_cipher_encrypt(s->cipher,
+ in_buf,
+ out_buf,
+ 512,
+ errp);
+ } else {
+ ret = qcrypto_cipher_decrypt(s->cipher,
+ in_buf,
+ out_buf,
+ 512,
+ errp);
+ }
+ if (ret < 0) {
+ return -1;
+ }
sector_num++;
in_buf += 512;
out_buf += 512;
}
+ return 0;
}
static int coroutine_fn copy_sectors(BlockDriverState *bs,
@@ -401,10 +422,15 @@ static int coroutine_fn copy_sectors(BlockDriverState *bs,
}
if (bs->encrypted) {
- assert(s->crypt_method);
- qcow2_encrypt_sectors(s, start_sect + n_start,
- iov.iov_base, iov.iov_base, n, 1,
- &s->aes_encrypt_key);
+ Error *err = NULL;
+ assert(s->cipher);
+ if (qcow2_encrypt_sectors(s, start_sect + n_start,
+ iov.iov_base, iov.iov_base, n,
+ true, &err) < 0) {
+ ret = -EIO;
+ error_free(err);
+ goto out;
+ }
}
ret = qcow2_pre_write_overlap_check(bs, 0,
diff --git a/block/qcow2.c b/block/qcow2.c
index e9e3fa5..7e14bcd 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -698,6 +698,11 @@ static int qcow2_open(BlockDriverState *bs, QDict
*options, int flags,
ret = -EINVAL;
goto fail;
}
+ if (!qcrypto_cipher_supports(QCRYPTO_CIPHER_ALG_AES_128)) {
+ error_setg(errp, "AES cipher not available");
+ ret = -EINVAL;
+ goto fail;
+ }
s->crypt_method_header = header.crypt_method;
if (s->crypt_method_header) {
bs->encrypted = 1;
@@ -1031,6 +1036,7 @@ static int qcow2_set_key(BlockDriverState *bs, const char
*key)
BDRVQcowState *s = bs->opaque;
uint8_t keybuf[16];
int len, i;
+ Error *err = NULL;
memset(keybuf, 0, 16);
len = strlen(key);
@@ -1042,30 +1048,21 @@ static int qcow2_set_key(BlockDriverState *bs, const
char *key)
keybuf[i] = key[i];
}
assert(bs->encrypted);
- s->crypt_method = s->crypt_method_header;
- if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0)
- return -1;
- if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0)
+ qcrypto_cipher_free(s->cipher);
+ s->cipher = qcrypto_cipher_new(
+ QCRYPTO_CIPHER_ALG_AES_128,
+ QCRYPTO_CIPHER_MODE_CBC,
+ keybuf, G_N_ELEMENTS(keybuf),
+ &err);
+
+ if (!s->cipher) {
+ /* XXX would be nice if errors in this method could
+ * be properly propagate to the caller. Would need
+ * the bdrv_set_key() API signature to be fixed. */
+ error_free(err);
return -1;
-#if 0
- /* test */
- {
- uint8_t in[16];
- uint8_t out[16];
- uint8_t tmp[16];
- for(i=0;i<16;i++)
- in[i] = i;
- AES_encrypt(in, tmp, &s->aes_encrypt_key);
- AES_decrypt(tmp, out, &s->aes_decrypt_key);
- for(i = 0; i < 16; i++)
- printf(" %02x", tmp[i]);
- printf("\n");
- for(i = 0; i < 16; i++)
- printf(" %02x", out[i]);
- printf("\n");
}
-#endif
return 0;
}
@@ -1108,7 +1105,7 @@ static int64_t coroutine_fn
qcow2_co_get_block_status(BlockDriverState *bs,
}
if (cluster_offset != 0 && ret != QCOW2_CLUSTER_COMPRESSED &&
- !s->crypt_method) {
+ !s->cipher) {
index_in_cluster = sector_num & (s->cluster_sectors - 1);
cluster_offset |= (index_in_cluster << BDRV_SECTOR_BITS);
status |= BDRV_BLOCK_OFFSET_VALID | cluster_offset;
@@ -1158,7 +1155,7 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState
*bs, int64_t sector_num,
/* prepare next request */
cur_nr_sectors = remaining_sectors;
- if (s->crypt_method) {
+ if (s->cipher) {
cur_nr_sectors = MIN(cur_nr_sectors,
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors);
}
@@ -1230,7 +1227,7 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState
*bs, int64_t sector_num,
}
if (bs->encrypted) {
- assert(s->crypt_method);
+ assert(s->cipher);
/*
* For encrypted images, read everything into a temporary
@@ -1263,9 +1260,15 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState
*bs, int64_t sector_num,
goto fail;
}
if (bs->encrypted) {
- assert(s->crypt_method);
- qcow2_encrypt_sectors(s, sector_num, cluster_data,
- cluster_data, cur_nr_sectors, 0, &s->aes_decrypt_key);
+ assert(s->cipher);
+ Error *err = NULL;
+ if (qcow2_encrypt_sectors(s, sector_num, cluster_data,
+ cluster_data, cur_nr_sectors, false,
+ &err) < 0) {
+ error_free(err);
+ ret = -EIO;
+ goto fail;
+ }
qemu_iovec_from_buf(qiov, bytes_done,
cluster_data, 512 * cur_nr_sectors);
}
@@ -1343,7 +1346,8 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState
*bs,
cur_nr_sectors * 512);
if (bs->encrypted) {
- assert(s->crypt_method);
+ Error *err = NULL;
+ assert(s->cipher);
if (!cluster_data) {
cluster_data = qemu_try_blockalign(bs->file,
QCOW_MAX_CRYPT_CLUSTERS
@@ -1358,8 +1362,13 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState
*bs,
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
qemu_iovec_to_buf(&hd_qiov, 0, cluster_data, hd_qiov.size);
- qcow2_encrypt_sectors(s, sector_num, cluster_data,
- cluster_data, cur_nr_sectors, 1, &s->aes_encrypt_key);
+ if (qcow2_encrypt_sectors(s, sector_num, cluster_data,
+ cluster_data, cur_nr_sectors,
+ true, &err) < 0) {
+ error_free(err);
+ ret = -EIO;
+ goto fail;
+ }
qemu_iovec_reset(&hd_qiov);
qemu_iovec_add(&hd_qiov, cluster_data,
@@ -1465,6 +1474,9 @@ static void qcow2_close(BlockDriverState *bs)
qcow2_cache_destroy(bs, s->l2_table_cache);
qcow2_cache_destroy(bs, s->refcount_block_cache);
+ qcrypto_cipher_free(s->cipher);
+ s->cipher = NULL;
+
g_free(s->unknown_header_fields);
cleanup_unknown_header_ext(bs);
@@ -1481,9 +1493,7 @@ static void qcow2_invalidate_cache(BlockDriverState *bs,
Error **errp)
{
BDRVQcowState *s = bs->opaque;
int flags = s->flags;
- AES_KEY aes_encrypt_key;
- AES_KEY aes_decrypt_key;
- uint32_t crypt_method = 0;
+ QCryptoCipher *cipher = NULL;
QDict *options;
Error *local_err = NULL;
int ret;
@@ -1493,12 +1503,8 @@ static void qcow2_invalidate_cache(BlockDriverState *bs,
Error **errp)
* that means we don't have to worry about reopening them here.
*/
- if (bs->encrypted) {
- assert(s->crypt_method);
- crypt_method = s->crypt_method;
- memcpy(&aes_encrypt_key, &s->aes_encrypt_key, sizeof(aes_encrypt_key));
- memcpy(&aes_decrypt_key, &s->aes_decrypt_key, sizeof(aes_decrypt_key));
- }
+ cipher = s->cipher;
+ s->cipher = NULL;
qcow2_close(bs);
@@ -1523,11 +1529,7 @@ static void qcow2_invalidate_cache(BlockDriverState *bs,
Error **errp)
return;
}
- if (bs->encrypted) {
- s->crypt_method = crypt_method;
- memcpy(&s->aes_encrypt_key, &aes_encrypt_key, sizeof(aes_encrypt_key));
- memcpy(&s->aes_decrypt_key, &aes_decrypt_key, sizeof(aes_decrypt_key));
- }
+ s->cipher = cipher;
}
static size_t header_ext_add(char *buf, uint32_t magic, const void *s,
@@ -2728,8 +2730,9 @@ static int qcow2_amend_options(BlockDriverState *bs,
QemuOpts *opts,
backing_format = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT);
} else if (!strcmp(desc->name, BLOCK_OPT_ENCRYPT)) {
encrypt = qemu_opt_get_bool(opts, BLOCK_OPT_ENCRYPT,
- s->crypt_method);
- if (encrypt != !!s->crypt_method) {
+ !!s->cipher);
+
+ if (encrypt != !!s->cipher) {
fprintf(stderr, "Changing the encryption flag is not "
"supported.\n");
return -ENOTSUP;
diff --git a/block/qcow2.h b/block/qcow2.h
index 462147c..72e1328 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -25,7 +25,7 @@
#ifndef BLOCK_QCOW2_H
#define BLOCK_QCOW2_H
-#include "crypto/aes.h"
+#include "crypto/cipher.h"
#include "block/coroutine.h"
//#define DEBUG_ALLOC
@@ -253,10 +253,8 @@ typedef struct BDRVQcowState {
CoMutex lock;
- uint32_t crypt_method; /* current crypt method, 0 if no key yet */
+ QCryptoCipher *cipher; /* current cipher, NULL if no key yet */
uint32_t crypt_method_header;
- AES_KEY aes_encrypt_key;
- AES_KEY aes_decrypt_key;
uint64_t snapshots_offset;
int snapshots_size;
unsigned int nb_snapshots;
@@ -536,10 +534,9 @@ int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t
min_size,
int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
void qcow2_l2_cache_reset(BlockDriverState *bs);
int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
-void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
- uint8_t *out_buf, const uint8_t *in_buf,
- int nb_sectors, int enc,
- const AES_KEY *key);
+int qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
+ uint8_t *out_buf, const uint8_t *in_buf,
+ int nb_sectors, bool enc, Error **errp);
int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
int *num, uint64_t *cluster_offset);
--
2.4.2
