Re: [Qemu-devel] [PATCH RFC 1/2] block: Limit opening of encrypted images to qemu-img

[Daniel P. Berrange]

On Tue, Mar 10, 2015 at 06:26:39PM +0100, Markus Armbruster wrote:
> Signed-off-by: Markus Armbruster <address@hidden>
> ---
>  block/qcow.c          | 5 +++++
>  block/qcow2.c         | 5 +++++
>  include/block/block.h | 3 +--
>  qemu-img.c            | 1 +
>  4 files changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/block/qcow.c b/block/qcow.c
> index 0558969..f54fc86 100644
> --- a/block/qcow.c
> +++ b/block/qcow.c
> @@ -155,6 +155,11 @@ static int qcow_open(BlockDriverState *bs, QDict 
> *options, int flags,
>      }
>      s->crypt_method_header = header.crypt_method;
>      if (s->crypt_method_header) {
> +        if (!(flags & BDRV_O_CRYPT_OK)) {
> +            error_setg(errp, "image is encrypted, use qemu-img to decrypt 
> it");
> +            ret = -EINVAL;
> +            goto fail;
> +        }
>          bs->encrypted = 1;
>      }
>      s->cluster_bits = header.cluster_bits;
> diff --git a/block/qcow2.c b/block/qcow2.c
> index 50e0a94..b12c67a 100644
> --- a/block/qcow2.c
> +++ b/block/qcow2.c
> @@ -693,6 +693,11 @@ static int qcow2_open(BlockDriverState *bs, QDict 
> *options, int flags,
>      }
>      s->crypt_method_header = header.crypt_method;
>      if (s->crypt_method_header) {
> +        if (!(flags & BDRV_O_CRYPT_OK)) {
> +            error_setg(errp, "image is encrypted, use qemu-img to decrypt 
> it");
> +            ret = -EINVAL;
> +            goto fail;
> +        }
>          bs->encrypted = 1;
>      }
>  
> diff --git a/include/block/block.h b/include/block/block.h
> index 649c269..76b6d3c 100644
> --- a/include/block/block.h
> +++ b/include/block/block.h
> @@ -76,6 +76,7 @@ typedef enum {
>  #define BDRV_O_PROTOCOL    0x8000  /* if no block driver is explicitly given:
>                                        select an appropriate protocol driver,
>                                        ignoring the format layer */
> +#define BDRV_O_CRYPT_OK    0x10000 /* open even when image is encrypted */
>  
>  #define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_CACHE_WB | 
> BDRV_O_NO_FLUSH)
>  
> @@ -382,8 +383,6 @@ 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);

Nitpick, this method isn't deleted until your next patch, so this belongs
there.

> -int bdrv_query_missing_keys(void);

Fun, a method which doesn't even exist :-)

>  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/qemu-img.c b/qemu-img.c
> index 7ac7f56..bcd7d3f 100644
> --- a/qemu-img.c
> +++ b/qemu-img.c
> @@ -302,6 +302,7 @@ static BlockBackend *img_open(const char *id, const char 
> *filename,
>          qdict_put(options, "driver", qstring_from_str(fmt));
>      }
>  
> +    flags |= BDRV_O_CRYPT_OK;
>      blk = blk_new_open(id, filename, NULL, options, flags, &local_err);
>      if (!blk) {
>          error_report("Could not open '%s': %s", filename,

Regards,
Daniel
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