[Qemu-block] [PATCH WIP 13/30] block: remove all encryption handling APIs

[Daniel P. Berrange]

Now that all encryption keys must be provided upfront via
the QCryptoSecret API and associated block driver properties
there is no need for any explicit encryption handling APIs
in the block layer. Encryption can be handled transparently
within the block driver. We only retain an API for querying
whether an image is encrypted or not, since that is a
potentially useful piece of metadata to report to the user.

Signed-off-by: Daniel P. Berrange <address@hidden>
---
 block.c                    | 81 ++--------------------------------------------
 block/qapi.c               |  2 +-
 block/qcow.c               | 19 -----------
 block/qcow2.c              | 19 -----------
 blockdev.c                 | 40 ++---------------------
 include/block/block.h      |  4 ---
 tests/qemu-iotests/087.out |  4 +--
 7 files changed, 7 insertions(+), 162 deletions(-)

diff --git a/block.c b/block.c
index 3a7324b..f6d6067 100644
--- a/block.c
+++ b/block.c
@@ -1550,17 +1550,8 @@ static int bdrv_open_inherit(BlockDriverState **pbs, 
const char *filename,
         goto close_and_fail;
     }
 
-    if (!bdrv_key_required(bs)) {
-        if (bs->blk) {
-            blk_dev_change_media_cb(bs->blk, true);
-        }
-    } else if (!runstate_check(RUN_STATE_PRELAUNCH)
-               && !runstate_check(RUN_STATE_INMIGRATE)
-               && !runstate_check(RUN_STATE_PAUSED)) { /* HACK */
-        error_setg(errp,
-                   "Guest must be stopped for opening of encrypted image");
-        ret = -EBUSY;
-        goto close_and_fail;
+    if (bs->blk) {
+        blk_dev_change_media_cb(bs->blk, true);
     }
 
     QDECREF(options);
@@ -2530,74 +2521,6 @@ int bdrv_is_encrypted(BlockDriverState *bs)
     return bs->encrypted;
 }
 
-int bdrv_key_required(BlockDriverState *bs)
-{
-    BdrvChild *backing = bs->backing;
-
-    if (backing && backing->bs->encrypted && !backing->bs->valid_key) {
-        return 1;
-    }
-    return (bs->encrypted && !bs->valid_key);
-}
-
-int bdrv_set_key(BlockDriverState *bs, const char *key)
-{
-    int ret;
-    if (bs->backing && bs->backing->bs->encrypted) {
-        ret = bdrv_set_key(bs->backing->bs, key);
-        if (ret < 0)
-            return ret;
-        if (!bs->encrypted)
-            return 0;
-    }
-    if (!bs->encrypted) {
-        return -EINVAL;
-    } else if (!bs->drv || !bs->drv->bdrv_set_key) {
-        return -ENOMEDIUM;
-    }
-    ret = bs->drv->bdrv_set_key(bs, key);
-    if (ret < 0) {
-        bs->valid_key = 0;
-    } else if (!bs->valid_key) {
-        bs->valid_key = 1;
-        if (bs->blk) {
-            /* call the change callback now, we skipped it on open */
-            blk_dev_change_media_cb(bs->blk, true);
-        }
-    }
-    return ret;
-}
-
-/*
- * Provide an encryption key for @bs.
- * If @key is non-null:
- *     If @bs is not encrypted, fail.
- *     Else if the key is invalid, fail.
- *     Else set @bs's key to @key, replacing the existing key, if any.
- * If @key is null:
- *     If @bs is encrypted and still lacks a key, fail.
- *     Else do nothing.
- * On failure, store an error object through @errp if non-null.
- */
-void bdrv_add_key(BlockDriverState *bs, const char *key, Error **errp)
-{
-    if (key) {
-        if (!bdrv_is_encrypted(bs)) {
-            error_setg(errp, "Node '%s' is not encrypted",
-                      bdrv_get_device_or_node_name(bs));
-        } else if (bdrv_set_key(bs, key) < 0) {
-            error_setg(errp, QERR_INVALID_PASSWORD);
-        }
-    } else {
-        if (bdrv_key_required(bs)) {
-            error_set(errp, ERROR_CLASS_DEVICE_ENCRYPTED,
-                      "'%s' (%s) is encrypted",
-                      bdrv_get_device_or_node_name(bs),
-                      bdrv_get_encrypted_filename(bs));
-        }
-    }
-}
-
 const char *bdrv_get_format_name(BlockDriverState *bs)
 {
     return bs->drv ? bs->drv->format_name : NULL;
diff --git a/block/qapi.c b/block/qapi.c
index d20262d..e5e2e80 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -42,7 +42,7 @@ BlockDeviceInfo *bdrv_block_device_info(BlockDriverState *bs, 
Error **errp)
     info->ro                     = bs->read_only;
     info->drv                    = g_strdup(bs->drv->format_name);
     info->encrypted              = bs->encrypted;
-    info->encryption_key_missing = bdrv_key_required(bs);
+    info->encryption_key_missing = false;
 
     info->cache = g_new(BlockdevCacheInfo, 1);
     *info->cache = (BlockdevCacheInfo) {
diff --git a/block/qcow.c b/block/qcow.c
index ff80ef5..ccf6de1 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -222,11 +222,6 @@ 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;
@@ -335,19 +330,6 @@ static int qcow_reopen_prepare(BDRVReopenState *state,
     return 0;
 }
 
-static int qcow_set_key(BlockDriverState *bs, const char *key)
-{
-    BDRVQcowState *s = bs->opaque;
-
-    assert(bs->encrypted);
-    qcrypto_cipher_free(s->cipher);
-    s->cipher = qcow_get_cipher_from_key(key, NULL);
-    if (!s->cipher) {
-        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 */
@@ -1078,7 +1060,6 @@ static BlockDriver bdrv_qcow = {
     .bdrv_co_writev         = qcow_co_writev,
     .bdrv_co_get_block_status   = qcow_co_get_block_status,
 
-    .bdrv_set_key           = qcow_set_key,
     .bdrv_make_empty        = qcow_make_empty,
     .bdrv_write_compressed  = qcow_write_compressed,
     .bdrv_get_info          = qcow_get_info,
diff --git a/block/qcow2.c b/block/qcow2.c
index d326148..900eed1 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1026,11 +1026,6 @@ 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;
@@ -1262,19 +1257,6 @@ static void qcow2_refresh_limits(BlockDriverState *bs, 
Error **errp)
     bs->bl.write_zeroes_alignment = s->cluster_sectors;
 }
 
-static int qcow2_set_key(BlockDriverState *bs, const char *key)
-{
-    BDRVQcow2State *s = bs->opaque;
-
-    assert(bs->encrypted);
-    qcrypto_cipher_free(s->cipher);
-    s->cipher = qcow2_get_cipher_from_key(key, NULL);
-    if (!s->cipher) {
-        return -1;
-    }
-    return 0;
-}
-
 static int qcow2_reopen_prepare(BDRVReopenState *state,
                                 BlockReopenQueue *queue, Error **errp)
 {
@@ -3191,7 +3173,6 @@ BlockDriver bdrv_qcow2 = {
     .bdrv_create        = qcow2_create,
     .bdrv_has_zero_init = bdrv_has_zero_init_1,
     .bdrv_co_get_block_status = qcow2_co_get_block_status,
-    .bdrv_set_key       = qcow2_set_key,
 
     .bdrv_co_readv          = qcow2_co_readv,
     .bdrv_co_writev         = qcow2_co_writev,
diff --git a/blockdev.c b/blockdev.c
index 917ae06..2c90b5e 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -624,10 +624,6 @@ static BlockBackend *blockdev_init(const char *file, QDict 
*bs_opts,
             bdrv_set_io_limits(bs, &cfg);
         }
 
-        if (bdrv_key_required(bs)) {
-            autostart = 0;
-        }
-
         block_acct_init(blk_get_stats(blk), account_invalid, account_failed);
 
         if (!parse_stats_intervals(blk_get_stats(blk), interval_list, errp)) {
@@ -2263,24 +2259,8 @@ void qmp_block_passwd(bool has_device, const char 
*device,
                       bool has_node_name, const char *node_name,
                       const char *password, Error **errp)
 {
-    Error *local_err = NULL;
-    BlockDriverState *bs;
-    AioContext *aio_context;
-
-    bs = bdrv_lookup_bs(has_device ? device : NULL,
-                        has_node_name ? node_name : NULL,
-                        &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
-        return;
-    }
-
-    aio_context = bdrv_get_aio_context(bs);
-    aio_context_acquire(aio_context);
-
-    bdrv_add_key(bs, password, errp);
-
-    aio_context_release(aio_context);
+    error_setg_errno(errp, -ENOSYS,
+                     "Setting block passwords directly is no longer 
supported");
 }
 
 void qmp_blockdev_open_tray(const char *device, bool has_force, bool force,
@@ -2507,12 +2487,6 @@ void qmp_blockdev_change_medium(const char *device, 
const char *filename,
 
     blk_apply_root_state(blk, medium_bs);
 
-    bdrv_add_key(medium_bs, NULL, &err);
-    if (err) {
-        error_propagate(errp, err);
-        goto fail;
-    }
-
     qmp_blockdev_open_tray(device, false, false, &err);
     if (err) {
         error_propagate(errp, err);
@@ -3755,16 +3729,6 @@ void qmp_blockdev_add(BlockdevOptions *options, Error 
**errp)
         }
     }
 
-    if (bs && bdrv_key_required(bs)) {
-        if (blk) {
-            blk_unref(blk);
-        } else {
-            bdrv_unref(bs);
-        }
-        error_setg(errp, "blockdev-add doesn't support encrypted devices");
-        goto fail;
-    }
-
 fail:
     qmp_output_visitor_cleanup(ov);
 }
diff --git a/include/block/block.h b/include/block/block.h
index ccd2f72..ba42688 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -412,10 +412,6 @@ bool bdrv_chain_contains(BlockDriverState *top, 
BlockDriverState *base);
 BlockDriverState *bdrv_next_node(BlockDriverState *bs);
 BlockDriverState *bdrv_next(BlockDriverState *bs);
 int bdrv_is_encrypted(BlockDriverState *bs);
-int bdrv_key_required(BlockDriverState *bs);
-int bdrv_set_key(BlockDriverState *bs, const char *key);
-void bdrv_add_key(BlockDriverState *bs, const char *key, Error **errp);
-int bdrv_query_missing_keys(void);
 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
                          void *opaque);
 const char *bdrv_get_node_name(const BlockDriverState *bs);
diff --git a/tests/qemu-iotests/087.out b/tests/qemu-iotests/087.out
index 85752bb..2b55b1b 100644
--- a/tests/qemu-iotests/087.out
+++ b/tests/qemu-iotests/087.out
@@ -52,7 +52,7 @@ QMP_VERSION
 Encrypted images are deprecated
 Support for them will be removed in a future release.
 You can use 'qemu-img convert' to convert your image to an unencrypted one.
-{"error": {"class": "GenericError", "desc": "blockdev-add doesn't support 
encrypted devices"}}
+{"return": {}}
 {"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": 
"SHUTDOWN"}
 
@@ -63,7 +63,7 @@ QMP_VERSION
 Encrypted images are deprecated
 Support for them will be removed in a future release.
 You can use 'qemu-img convert' to convert your image to an unencrypted one.
-{"error": {"class": "GenericError", "desc": "Guest must be stopped for opening 
of encrypted image"}}
+{"return": {}}
 {"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": 
"SHUTDOWN"}
 
-- 
2.5.0