On 12/30/2017 10:35 AM, Longpeng(Mike) wrote:
> From: Gonglei <arei.gong...@huawei.com>
>
> The virtio crypto device is a virtual crypto device (ie. hardware
> crypto accelerator card). Currently, the virtio crypto device provides
> the following crypto services: CIPHER, MAC, HASH, and AEAD.
>
> In this patch, CIPHER, MAC, HASH, AEAD services are introduced.
>
> VIRTIO-153
>
> Signed-off-by: Gonglei <arei.gong...@huawei.com>
> Signed-off-by: Zhoujian <jianjay.z...@huawei.com>
> Signed-off-by: Longpeng(Mike) <longpe...@huawei.com>
> ---
> acknowledgements.tex | 4 +
> content.tex | 2 +
> virtio-crypto.tex | 1525
> ++++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 1531 insertions(+)
> create mode 100644 virtio-crypto.tex
>
> diff --git a/acknowledgements.tex b/acknowledgements.tex
> index 2d893d9..cdde247 100644
> --- a/acknowledgements.tex
> +++ b/acknowledgements.tex
> @@ -16,10 +16,13 @@ Daniel Kiper, Oracle \newline
> Geoff Brown, Machine-to-Machine Intelligence (M2MI) Corporation \newline
> Gershon Janssen, Individual Member \newline
> James Bottomley, Parallels IP Holdings GmbH \newline
> +Jian Zhou, Huawei \newline
> +Lei Gong, Huawei \newline
> Luiz Capitulino, Red Hat \newline
> Michael S. Tsirkin, Red Hat \newline
> Paolo Bonzini, Red Hat \newline
> Pawel Moll, ARM \newline
> +Peng Long, Huawei \newline
> Richard Sohn, Alcatel-Lucent \newline
> Rusty Russell, IBM \newline
> Sasha Levin, Oracle \newline
> @@ -38,6 +41,7 @@ Brian Foley, ARM \newline
> David Alan Gilbert, Red Hat \newline
> Fam Zheng, Red Hat \newline
> Gerd Hoffmann, Red Hat \newline
> +Halil Pasic, IBM \newline
> Jason Wang, Red Hat \newline
> Laura Novich, Red Hat \newline
> Patrick Durusau, Technical Advisory Board, OASIS \newline
> diff --git a/content.tex b/content.tex
> index c840588..d1d3b09 100644
> --- a/content.tex
> +++ b/content.tex
> @@ -5819,6 +5819,8 @@ descriptor for the \field{sense_len}, \field{residual},
> \field{status_qualifier}, \field{status}, \field{response} and
> \field{sense} fields.
>
> +\input{virtio-crypto.tex}
> +
> \chapter{Reserved Feature Bits}\label{sec:Reserved Feature Bits}
>
> Currently these device-independent feature bits defined:
> diff --git a/virtio-crypto.tex b/virtio-crypto.tex
> new file mode 100644
> index 0000000..4bd5b51
> --- /dev/null
> +++ b/virtio-crypto.tex
> @@ -0,0 +1,1525 @@
> +\section{Crypto Device}\label{sec:Device Types / Crypto Device}
> +
> +The virtio crypto device is a virtual cryptography device as well as a
> +virtual cryptographic accelerator. The virtio crypto device provides the
> +following crypto services: CIPHER, MAC, HASH, and AEAD. Virtio crypto
> +devices have a single control queue and at least one data queue. Crypto
> +operation requests are placed into a data queue, and serviced by the
> +device. Some crypto operation requests are only valid in the context of a
> +session. The role of the control queue is facilitating control operation
> +requests. Sessions management is realized with control operation
> +requests.
> +
> +\subsection{Device ID}\label{sec:Device Types / Crypto Device / Device ID}
> +
> +20
> +
> +\subsection{Virtqueues}\label{sec:Device Types / Crypto Device / Virtqueues}
> +
> +\begin{description}
> +\item[0] dataq1
> +\item[\ldots]
> +\item[N-1] dataqN
> +\item[N] controlq
> +\end{description}
> +
> +N is set by \field{max_dataqueues}.
> +
> +\subsection{Feature bits}\label{sec:Device Types / Crypto Device / Feature
> bits}
> +
> +\begin{description}
> +\item VIRTIO_CRYPTO_F_REVISION_1 (0) revision 1. Revision 1 has a specific
> + request format and other enhancements (which result in some additional
> + requirements).
> +\item VIRTIO_CRYPTO_F_CIPHER_STATELESS_MODE (1) stateless mode requests are
> + supported by the CIPHER service.
> +\item VIRTIO_CRYPTO_F_HASH_STATELESS_MODE (2) stateless mode requests are
> + supported by the HASH service.
> +\item VIRTIO_CRYPTO_F_MAC_STATELESS_MODE (3) stateless mode requests are
> + supported by the MAC service.
> +\item VIRTIO_CRYPTO_F_AEAD_STATELESS_MODE (4) stateless mode requests are
> + supported by the AEAD service.
> +\end{description}
> +
> +
> +\subsubsection{Feature bit requirements}\label{sec:Device Types / Crypto
> Device / Feature bits}
> +
> +Some crypto feature bits require other crypto feature bits
> +(see \ref{drivernormative:Basic Facilities of a Virtio Device / Feature
> Bits}):
> +
> +\begin{description}
> +\item[VIRTIO_CRYPTO_F_CIPHER_STATELESS_MODE] Requires
> VIRTIO_CRYPTO_F_REVISION_1.
> +\item[VIRTIO_CRYPTO_F_HASH_STATELESS_MODE] Requires
> VIRTIO_CRYPTO_F_REVISION_1.
> +\item[VIRTIO_CRYPTO_F_MAC_STATELESS_MODE] Requires
> VIRTIO_CRYPTO_F_REVISION_1.
> +\item[VIRTIO_CRYPTO_F_AEAD_STATELESS_MODE] Requires
> VIRTIO_CRYPTO_F_REVISION_1.
> +\end{description}
> +
> +\subsection{Supported crypto services}\label{sec:Device Types / Crypto
> Device / Supported crypto services}
> +
> +The following crypto services are defined:
> +
> +\begin{lstlisting}
> +/* CIPHER service */
> +#define VIRTIO_CRYPTO_SERVICE_CIPHER 0
> +/* HASH service */
> +#define VIRTIO_CRYPTO_SERVICE_HASH 1
> +/* MAC (Message Authentication Codes) service */
> +#define VIRTIO_CRYPTO_SERVICE_MAC 2
> +/* AEAD (Authenticated Encryption with Associated Data) service */
> +#define VIRTIO_CRYPTO_SERVICE_AEAD 3
> +\end{lstlisting}
> +
> +The above constants designate bits used to indicate the which of crypto
> services are
> +offered by the device as described in, see \ref{sec:Device Types / Crypto
> Device / Device configuration layout}.
> +
> +\subsubsection{CIPHER services}\label{sec:Device Types / Crypto Device /
> Supported crypto services / CIPHER services}
> +
> +The following CIPHER algorithms are defined:
> +
> +\begin{lstlisting}
> +#define VIRTIO_CRYPTO_NO_CIPHER 0
> +#define VIRTIO_CRYPTO_CIPHER_ARC4 1
> +#define VIRTIO_CRYPTO_CIPHER_AES_ECB 2
> +#define VIRTIO_CRYPTO_CIPHER_AES_CBC 3
> +#define VIRTIO_CRYPTO_CIPHER_AES_CTR 4
> +#define VIRTIO_CRYPTO_CIPHER_DES_ECB 5
> +#define VIRTIO_CRYPTO_CIPHER_DES_CBC 6
> +#define VIRTIO_CRYPTO_CIPHER_3DES_ECB 7
> +#define VIRTIO_CRYPTO_CIPHER_3DES_CBC 8
> +#define VIRTIO_CRYPTO_CIPHER_3DES_CTR 9
> +#define VIRTIO_CRYPTO_CIPHER_KASUMI_F8 10
> +#define VIRTIO_CRYPTO_CIPHER_SNOW3G_UEA2 11
> +#define VIRTIO_CRYPTO_CIPHER_AES_F8 12
> +#define VIRTIO_CRYPTO_CIPHER_AES_XTS 13
> +#define VIRTIO_CRYPTO_CIPHER_ZUC_EEA3 14
> +\end{lstlisting}
> +
> +The above constants have two usages:
> +\begin{enumerate}
> +\item As bit numbers, used to tell the driver which CIPHER algorithms
> +are supported by the device, see \ref{sec:Device Types / Crypto Device /
> Device configuration layout}.
> +\item As values, used to designate the algorithm in (CIPHER type) crypto
> +operation requests, see \ref{sec:Device Types / Crypto Device / Device
> Operation / Control Virtqueue / Session operation}.
> +\end{enumerate}
> +
> +\subsubsection{HASH services}\label{sec:Device Types / Crypto Device /
> Supported crypto services / HASH services}
> +
> +The following HASH algorithms are defined:
> +
> +\begin{lstlisting}
> +#define VIRTIO_CRYPTO_NO_HASH 0
> +#define VIRTIO_CRYPTO_HASH_MD5 1
> +#define VIRTIO_CRYPTO_HASH_SHA1 2
> +#define VIRTIO_CRYPTO_HASH_SHA_224 3
> +#define VIRTIO_CRYPTO_HASH_SHA_256 4
> +#define VIRTIO_CRYPTO_HASH_SHA_384 5
> +#define VIRTIO_CRYPTO_HASH_SHA_512 6
> +#define VIRTIO_CRYPTO_HASH_SHA3_224 7
> +#define VIRTIO_CRYPTO_HASH_SHA3_256 8
> +#define VIRTIO_CRYPTO_HASH_SHA3_384 9
> +#define VIRTIO_CRYPTO_HASH_SHA3_512 10
> +#define VIRTIO_CRYPTO_HASH_SHA3_SHAKE128 11
> +#define VIRTIO_CRYPTO_HASH_SHA3_SHAKE256 12
> +\end{lstlisting}
> +
> +The above constants have two usages:
> +\begin{enumerate}
> +\item As bit numbers, used to tell the driver which HASH algorithms
> +are supported by the device, see \ref{sec:Device Types / Crypto Device /
> Device configuration layout}.
> +\item As values, used to designate the algorithm in (HASH type) crypto
> +operation requires, see \ref{sec:Device Types / Crypto Device / Device
> Operation / Control Virtqueue / Session operation}.
> +\end{enumerate}
> +
> +\subsubsection{MAC services}\label{sec:Device Types / Crypto Device /
> Supported crypto services / MAC services}
> +
> +The following MAC algorithms are defined:
> +
> +\begin{lstlisting}
> +#define VIRTIO_CRYPTO_NO_MAC 0
> +#define VIRTIO_CRYPTO_MAC_HMAC_MD5 1
> +#define VIRTIO_CRYPTO_MAC_HMAC_SHA1 2
> +#define VIRTIO_CRYPTO_MAC_HMAC_SHA_224 3
> +#define VIRTIO_CRYPTO_MAC_HMAC_SHA_256 4
> +#define VIRTIO_CRYPTO_MAC_HMAC_SHA_384 5
> +#define VIRTIO_CRYPTO_MAC_HMAC_SHA_512 6
> +#define VIRTIO_CRYPTO_MAC_CMAC_3DES 25
> +#define VIRTIO_CRYPTO_MAC_CMAC_AES 26
> +#define VIRTIO_CRYPTO_MAC_KASUMI_F9 27
> +#define VIRTIO_CRYPTO_MAC_SNOW3G_UIA2 28
> +#define VIRTIO_CRYPTO_MAC_GMAC_AES 41
> +#define VIRTIO_CRYPTO_MAC_GMAC_TWOFISH 42
> +#define VIRTIO_CRYPTO_MAC_CBCMAC_AES 49
> +#define VIRTIO_CRYPTO_MAC_CBCMAC_KASUMI_F9 50
> +#define VIRTIO_CRYPTO_MAC_XCBC_AES 53
> +#define VIRTIO_CRYPTO_MAC_ZUC_EIA3 54
> +\end{lstlisting}
> +
> +The above constants have two usages:
> +\begin{enumerate}
> +\item As bit numbers, used to tell the driver which MAC algorithms
> +are supported by the device, see \ref{sec:Device Types / Crypto Device /
> Device configuration layout}.
> +\item As values, used to designate the algorithm in (MAC type) crypto
> +operation requests, see \ref{sec:Device Types / Crypto Device / Device
> Operation / Control Virtqueue / Session operation}.
> +\end{enumerate}
> +
> +\subsubsection{AEAD services}\label{sec:Device Types / Crypto Device /
> Supported crypto services / AEAD services}
> +
> +The following AEAD algorithms are defined:
> +
> +\begin{lstlisting}
> +#define VIRTIO_CRYPTO_NO_AEAD 0
> +#define VIRTIO_CRYPTO_AEAD_GCM 1
> +#define VIRTIO_CRYPTO_AEAD_CCM 2
> +#define VIRTIO_CRYPTO_AEAD_CHACHA20_POLY1305 3
> +\end{lstlisting}
> +
> +The above constants have two usages:
> +\begin{enumerate}
> +\item As bit numbers, used to tell the driver which AEAD algorithms
> +are supported by the device, see \ref{sec:Device Types / Crypto Device /
> Device configuration layout}.
> +\item As values, used to designate the algorithm in (DEAD type) crypto
> +operation requests, see \ref{sec:Device Types / Crypto Device / Device
> Operation / Control Virtqueue / Session operation}.
> +\end{enumerate}
> +
> +\subsection{Device configuration layout}\label{sec:Device Types / Crypto
> Device / Device configuration layout}
> +
> +\begin{lstlisting}
> +struct virtio_crypto_config {
> + le32 status;
> + le32 max_dataqueues;
> + le32 crypto_services;
> + /* Detailed algorithms mask */
> + le32 cipher_algo_l;
> + le32 cipher_algo_h;
> + le32 hash_algo;
> + le32 mac_algo_l;
> + le32 mac_algo_h;
> + le32 aead_algo;
> + /* Maximum length of cipher key in bytes */
> + le32 max_cipher_key_len;
> + /* Maximum length of authenticated key in bytes */
> + le32 max_auth_key_len;
> + le32 reserved;
> + /* Maximum size of each crypto request's content in bytes */
> + le64 max_size;
> +};
> +\end{lstlisting}
> +
> +\begin{description}
> +\item Currently, only one \field(status) bit is defined:
> VIRTIO_CRYPTO_S_HW_READY
> + set indicates that the device is ready to process requests, this bit is
> read-only
> + for the driver
> +\begin{lstlisting}
> +#define VIRTIO_CRYPTO_S_HW_READY (1 << 0)
> +\end{lstlisting}
> +
> +\item[\field{max_dataqueues}] is the maximum number of data virtqueues that
> can
> + be configured by the device. The driver MAY use only one data queue, or
> it
> + can use more to achieve better performance.
> +
> +\item[\field{crypto_services}] crypto service offered, see \ref{sec:Device
> Types / Crypto Device / Supported crypto services}.
> +
> +\item[\field{cipher_algo_l}] CIPHER algorithms bits 0-31, see
> \ref{sec:Device Types / Crypto Device / Supported crypto services / CIPHER
> services}.
> +
> +\item[\field{cipher_algo_h}] CIPHER algorithms bits 32-63, see
> \ref{sec:Device Types / Crypto Device / Supported crypto services / CIPHER
> services}.
> +
> +\item[\field{hash_algo}] HASH algorithms bits, see \ref{sec:Device Types /
> Crypto Device / Supported crypto services / HASH services}.
> +
> +\item[\field{mac_algo_l}] MAC algorithms bits 0-31, see \ref{sec:Device
> Types / Crypto Device / Supported crypto services / MAC services}.
> +
> +\item[\field{mac_algo_h}] MAC algorithms bits 32-63, see \ref{sec:Device
> Types / Crypto Device / Supported crypto services / MAC services}.
> +
> +\item[\field{aead_algo}] AEAD algorithms bits, see \ref{sec:Device Types /
> Crypto Device / Supported crypto services / AEAD services}.
> +
> +\item[\field{max_cipher_key_len}] is the maximum length of cipher key
> supported by the device.
I can't find what happens if this limit isn't honored by the driver. Moreover
reading it is only SHOULD. Is it undefined behavior or should the device
reject/fail
such requests? I think in qemu implementation we fail the request.
This question is only about niceness. We are already good enough, IMHO:
since the implementer of the driver can't be sure what is going to happen
if the driver disregards max_cipher_key_len it is already an implicit
SHOULD.
> +
> +\item[\field{max_auth_key_len}] is the maximum length of authenticated key
> supported by the device.
Same here.
> +
> +\item[\field{reserved}] is reserved for future use.
> +
> +\item[\field{max_size}] is the maximum size of each crypto request's content
> supported by the device
s/device/device.
What a content of a request and how is its size calculated? Where is this
defined.
The question what happens if not honored applies similarly.
> +\end{description}
> +
> +\begin{note}
> +Unless explicitly stated otherwise all lengths and sizes are in bytes.
> +\end{note}
> +
> +\devicenormative{\subsubsection}{Device configuration layout}{Device Types /
> Crypto Device / Device configuration layout}
> +
> +\begin{itemize*}
> +\item The device MUST set \field{max_dataqueues} to between 1 and 65535
> inclusive.
> +\item The device MUST set the \field{status} with valid flags, undefined
> flags MUST NOT be set.
> +\item The device MUST accept and handle requests after \field{status} is set
> to VIRTIO_CRYPTO_S_HW_READY.
> +\item The device MUST set \field{crypto_services} based on the crypto
> services the device offers.
> +\item The device MUST set detailed algorithms masks for each service
> advertised by \field{crypto_services}.
> + The device MUST NOT set the not defined algorithms bits.
> +\item The device MUST set \field{max_size} to show the maximum size of
> crypto request the device supports.
> +\item The device MUST set \field{max_cipher_key_len} to show the maximum
> length of cipher key if the
> + device supports CIPHER service.
> +\item The device MUST set \field{max_auth_key_len} to show the maximum
> length of authenticated key if
> + the device supports MAC service.
> +\end{itemize*}
> +
> +\drivernormative{\subsubsection}{Device configuration layout}{Device Types /
> Crypto Device / Device configuration layout}
> +
> +\begin{itemize*}
> +\item The driver MUST read the \field{status} from the bottom bit of status
> to check whether the
> + VIRTIO_CRYPTO_S_HW_READY is set, and the driver MUST reread it after
> device reset.
> +\item The driver MUST NOT transmit any requests to the device if the
> VIRTIO_CRYPTO_S_HW_READY is not set.
> +\item The driver MUST read \field{max_dataqueues} field to discover the
> number of data queues the device supports.
> +\item The driver MUST read \field{crypto_services} field to discover which
> services the device is able to offer.
> +\item The driver SHOULD ignore the not defined algorithms bits.
> +\item The driver MUST read the detailed algorithms fields based on
> \field{crypto_services} field.
> +\item The driver SHOULD read \field{max_size} to discover the maximum size
> of crypto request the device supports.
> +\item The driver SHOULD read \field{max_cipher_key_len} to discover the
> maximum length of cipher key
> + the device supports.
> +\item The driver SHOULD read \field{max_auth_key_len} to discover the
> maximum length of authenticated
> + key the device supports.
> +\end{itemize*}
Seems to like a common practice in the virtio spec to say SHOULD read some
config space parameter in a driver normative but then having no driver normative
about the operational implications of the parameter.
While I do think that the reader is usually fully capable of inferring
the operational requirement, I find it a bit strange: having the operational
stuff explicit (and possibly needs to be read from the config space implicit)
seems more straight forward to me.
Anyway, you are consistent with the rest of the spec, so prefer keeping it
like this.
> +
> +\subsection{Device Initialization}\label{sec:Device Types / Crypto Device /
> Device Initialization}
> +
> +\drivernormative{\subsubsection}{Device Initialization}{Device Types /
> Crypto Device / Device Initialization}
> +
> +\begin{itemize*}
> +\item The driver MUST configure and initialize all virtqueues.
> +\item The driver MUST read the supported crypto services from bits of
> \field{crypto_services}.
> +\item The driver MUST read the supported algorithms based on
> \field{crypto_services} field.
> +\end{itemize*}
> +
> +\subsection{Device Operation}\label{sec:Device Types / Crypto Device /
> Device Operation}
> +
> +The operation of a virtio crypto device is driven by requests placed on the
> virtqueues.
> +Requests consist of a queue-type specific header (specifying among others
> the operation)
> +and an operation specific payload.
> +
> +If VIRTIO_CRYPTO_F_REVISION_1 is negotiated the device may support both
> session mode
> +(See \ref{sec:Device Types / Crypto Device / Device Operation / Control
> Virtqueue / Session operation})
> +and stateless mode operation requests.
> +In stateless mode all operation parameters are supplied as a part of each
> request,
> +while in session mode, some or all operation parameters are managed within
> the
> +session. Stateless mode is guarded by feature bits 0-4 on a service level. If
> +stateless mode is negotiated for a service, the service is available both in
> +session and stateless mode; otherwise it's only available in session mode.
How about the following?
"""
If stateless mode is negotiated for a service, the service accepts both session
mode and stateless
requests; otherwise stateless mode requests are rejected (via operation status).
"""
I prefer it because i think it makes clearer than session mode and stateless
mode are concepts that apply on request and not on service (or let's say queue)
level.
> +
> +\subsubsection{Operation Status}\label{sec:Device Types / Crypto Device /
> Device Operation / Operation status}
> +The device MUST return a status code as part of the operation (both session
> +operation and service operation) result. The valid operation status as
> follows:
> +
> +\begin{lstlisting}
> +enum VIRTIO_CRYPTO_STATUS {
> + VIRTIO_CRYPTO_OK = 0,
> + VIRTIO_CRYPTO_ERR = 1,
> + VIRTIO_CRYPTO_BADMSG = 2,
> + VIRTIO_CRYPTO_NOTSUPP = 3,
> + VIRTIO_CRYPTO_INVSESS = 4,
> + VIRTIO_CRYPTO_NOSPC = 5,
> + VIRTIO_CRYPTO_MAX
> +};
> +\end{lstlisting}
> +
> +\begin{itemize*}
> +\item VIRTIO_CRYPTO_OK: success.
> +\item VIRTIO_CRYPTO_BADMSG: authentication failed (only when AEAD
> decryption).
> +\item VIRTIO_CRYPTO_NOTSUPP: operation or algorithm is unsupported.
> +\item VIRTIO_CRYPTO_INVSESS: invalid session ID when executing crypto
> operations.
> +\item VIRTIO_CRYPTO_NOSPC: no free session ID (only when the
> VIRTIO_CRYPTO_F_REVISION_1
> + feature bit is negotiated).
> +\item VIRTIO_CRYPTO_ERR: any failure not mentioned above occurs.
> +\end{itemize*}
> +
Just thinking loud: We don't seem to be able to differentiate between device
detected a driver (guest) bug, and something went wrong with the backend.
I'm not sure differentiating between the two is useful in the first place.
> +\subsubsection{Control Virtqueue}\label{sec:Device Types / Crypto Device /
> Device Operation / Control Virtqueue}
> +
> +The driver uses the control virtqueue to send control commands to the
> +device, such as session operations (See \ref{sec:Device Types / Crypto
> Device / Device
> +Operation / Control Virtqueue / Session operation}).
> +
> +The header for controlq is of the following form:
> +\begin{lstlisting}
> +#define VIRTIO_CRYPTO_OPCODE(service, op) (((service) << 8) | (op))
> +
> +struct virtio_crypto_ctrl_header {
> +#define VIRTIO_CRYPTO_CIPHER_CREATE_SESSION \
> + VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_CIPHER, 0x02)
> +#define VIRTIO_CRYPTO_CIPHER_DESTROY_SESSION \
> + VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_CIPHER, 0x03)
> +#define VIRTIO_CRYPTO_HASH_CREATE_SESSION \
> + VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_HASH, 0x02)
> +#define VIRTIO_CRYPTO_HASH_DESTROY_SESSION \
> + VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_HASH, 0x03)
> +#define VIRTIO_CRYPTO_MAC_CREATE_SESSION \
> + VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_MAC, 0x02)
> +#define VIRTIO_CRYPTO_MAC_DESTROY_SESSION \
> + VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_MAC, 0x03)
> +#define VIRTIO_CRYPTO_AEAD_CREATE_SESSION \
> + VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_AEAD, 0x02)
> +#define VIRTIO_CRYPTO_AEAD_DESTROY_SESSION \
> + VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_AEAD, 0x03)
> + le32 opcode;
> + /* algo should be service-specific algorithms */
> + le32 algo;
> + le32 flag;
> + le32 reserved;
> +};
> +\end{lstlisting}
> +
> +The controlq request is composed of four parts:
> +\begin{lstlisting}
> +struct virtio_crypto_op_ctrl_req {
> + /* Device read only portion */
> +
> + struct virtio_crypto_ctrl_header header;
> +
> +#define VIRTIO_CRYPTO_CTRLQ_OP_SPEC_HDR_LEGACY 56
> + /* fixed length fields, opcode specific */
> + u8 op_flf[flf_len];
> +
> + /* variable length fields, opcode specific */
> + u8 op_vlf[vlf_len];
> +
> + /* Device write only portion */
> +
> + /* op result or completion status */
> + u8 op_outcome[outcome_len];
> +};
> +\end{lstlisting}
> +
> +\field{header} is a general header (see above).
> +
> +\field{op_flf} is the opcode (in \field{header}) specific fixed-length
> paramenters.
> +
> +\field{flf_len} depends on the VIRTIO_CRYPTO_F_REVISION_1 feature bit (see
> below).
> +
> +\field{op_vlf} is the opcode (in \field{header}) specific variable-length
> paramenters.
> +
> +\field{vlf_len} is the size of the specific structure used.
> +\begin{note}
> +The \field{vlf_len} of session-destroy operation and the hash-session-create
> +operation is ZERO.
> +\end{note}
> +
> +\begin{itemize*}
> +\item If the opcode (in \field{header}) is
> VIRTIO_CRYPTO_CIPHER_CREATE_SESSION
> + then \field{op_flf} is struct virtio_crypto_sym_create_session_flf if
> + VIRTIO_CRYPTO_F_REVISION_1 is negotiated and struct
> virtio_crypto_sym_create_session_flf if
> + padded to 56 bytes if NOT negotiated, and \field{op_vlf} is struct
> + virtio_crypto_sym_create_session_vlf.
> +\item If the opcode (in \field{header}) is VIRTIO_CRYPTO_HASH_CREATE_SESSION
> + then \field{op_flf} is struct virtio_crypto_hash_create_session_flf if
> + VIRTIO_CRYPTO_F_REVISION_1 is negotiated and struct
> virtio_crypto_hash_create_session_flf if
> + padded to 56 bytes if NOT negotiated.
> +\item If the opcode (in \field{header}) is VIRTIO_CRYPTO_MAC_CREATE_SESSION
> + then \field{op_flf} is struct virtio_crypto_mac_create_session_flf if
> + VIRTIO_CRYPTO_F_REVISION_1 is negotiated and struct
> virtio_crypto_mac_create_session_flf if
> + padded to 56 bytes if NOT negotiated, and \field{op_vlf} is struct
> + virtio_crypto_mac_create_session_vlf.
> +\end{itemize*}
> +\item If the opcode (in \field{header}) is VIRTIO_CRYPTO_AEAD_CREATE_SESSION
> + then \field{op_flf} is struct virtio_crypto_aead_create_session_flf if
> + VIRTIO_CRYPTO_F_REVISION_1 is negotiated and struct
> virtio_crypto_aead_create_session_flf if
> + padded to 56 bytes if NOT negotiated, and \field{op_vlf} is struct
> + virtio_crypto_aead_create_session_vlf.
> +\item If the opcode (in \field{header}) is
> VIRTIO_CRYPTO_CIPHER_DESTROY_SESSION
> + or VIRTIO_CRYPTO_HASH_DESTROY_SESSION or
> VIRTIO_CRYPTO_MAC_DESTROY_SESSION or
> + VIRTIO_CRYPTO_AEAD_DESTROY_SESSION then \field{op_flf} is struct
> + virtio_crypto_destroy_session_flf if VIRTIO_CRYPTO_F_REVISION_1 is
> negotiated and
> + struct virtio_crypto_destroy_session_flf if padded to 56 bytes if NOT
> negotiated.
> +\end{itemize*}
> +
> +\field{op_outcome} stores the result of operation and must be struct
> +virtio_crypto_destroy_session_input for session-destroy operation or
> +struct virtio_crypto_session_input.
> +
> +\field{outcome_len} is the size of the structure used.
> +
> +
> +\paragraph{Session operation}\label{sec:Device Types / Crypto Device / Device
> +Operation / Control Virtqueue / Session operation}
> +
> +The session is a handle which describes the cryptographic parameters to be
> +applied to a number of buffers.
> +
> +The following structure stores the result of session creation set by the
> device:
> +
> +\begin{lstlisting}
> +struct virtio_crypto_session_input {
> + /* Device write only portion */
I think you cann drop this comment along with the following similar
comments. We have already told whats device read only and what is
device write only in virtio_crypto_op_ctrl_req.
Restating it at each struct is redundant and IMHO just confusing. The
R/W is determined by where does the struct sit in the request.
> + le64 session_id;
> + le32 status;
> + le32 padding;
> +};
> +\end{lstlisting}
> +
> +A request to destroy a session includes the following information:
> +
> +\begin{lstlisting}
> +struct virtio_crypto_destroy_session_flf {
> + /* Device read only portion */
> + le64 session_id;
> +};
> +
> +struct virtio_crypto_destroy_session_input {
> + /* Device write only portion */
> + le32 status;
> + le32 padding;
> +};
> +\end{lstlisting}
> +
> +
> +\subparagraph{Session operation: HASH session}\label{sec:Device Types /
> Crypto Device / Device
> +Operation / Control Virtqueue / Session operation / Session operation: HASH
> session}
> +
> +The fixed-length paramenters of HASH session requests is as follows:
> +
> +\begin{lstlisting}
> +struct virtio_crypto_hash_create_session_flf {
> + /* Device read only portion */
> +
> + /* See VIRTIO_CRYPTO_HASH_* above */
> + le32 algo;
> + /* hash result length */
> + le32 hash_result_len;
> +};
> +\end{lstlisting}
> +
> +
> +\subparagraph{Session operation: MAC session}\label{sec:Device Types /
> Crypto Device / Device
> +Operation / Control Virtqueue / Session operation / Session operation: MAC
> session}
> +
> +The fixed-length and the variable-length parameters of MAC session requests
> are as follows:
> +
> +\begin{lstlisting}
> +struct virtio_crypto_mac_create_session_flf {
> + /* Device read only portion */
> +
> + /* See VIRTIO_CRYPTO_MAC_* above */
> + le32 algo;
> + /* hash result length */
> + le32 hash_result_len;
> + /* length of authenticated key */
> + le32 auth_key_len;
> + le32 padding;
> +};
> +
> +struct virtio_crypto_mac_create_session_vlf {
> + /* Device read only portion */
> +
> + /* The authenticated key */
> + u8 auth_key[auth_key_len];
> +};
> +\end{lstlisting}
> +
> +The length of \field{auth_key} is specified in \field{auth_key_len} in the
> struct
> +virtio_crypto_mac_create_session_flf.
> +
> +
> +\subparagraph{Session operation: Symmetric algorithms
> session}\label{sec:Device Types / Crypto Device / Device
> +Operation / Control Virtqueue / Session operation / Session operation:
> Symmetric algorithms session}
> +
> +The request of symmetric session could be the CIPHER algorithms request
> +or the chain algorithms (chaining CIPHER and HASH/MAC) request.
> +
> +The fixed-length and the variable-length parameters of CIPHER session
> requests are as follows:
> +
> +\begin{lstlisting}
> +struct virtio_crypto_cipher_session_flf {
> + /* Device read only portion */
> +
> + /* See VIRTIO_CRYPTO_CIPHER* above */
> + le32 algo;
> + /* length of key */
> + le32 keylen;
> +#define VIRTIO_CRYPTO_OP_ENCRYPT 1
> +#define VIRTIO_CRYPTO_OP_DECRYPT 2
> + /* encryption or decryption */
> + le32 op;
> + le32 padding;
> +};
> +
> +struct virtio_crypto_cipher_session_vlf {
> + /* Device read only portion */
> +
> + /* The cipher key */
> + u8 cipher_key[keylen];
> +};
> +\end{lstlisting}
> +
> +The length of \field{cipher_key} is specified in \field{keylen} in the struct
> +virtio_crypto_cipher_session_flf.
> +
> +The fixed-length and the variable-length parameters of Chain session
> requests are as follows:
> +
> +\begin{lstlisting}
> +struct virtio_crypto_alg_chain_session_flf {
> + /* Device read only portion */
> +
> +#define VIRTIO_CRYPTO_SYM_ALG_CHAIN_ORDER_HASH_THEN_CIPHER 1
> +#define VIRTIO_CRYPTO_SYM_ALG_CHAIN_ORDER_CIPHER_THEN_HASH 2
> + le32 alg_chain_order;
> +/* Plain hash */
> +#define VIRTIO_CRYPTO_SYM_HASH_MODE_PLAIN 1
> +/* Authenticated hash (mac) */
> +#define VIRTIO_CRYPTO_SYM_HASH_MODE_AUTH 2
> +/* Nested hash */
> +#define VIRTIO_CRYPTO_SYM_HASH_MODE_NESTED 3
> + le32 hash_mode;
> + struct virtio_crypto_cipher_session_flf cipher_hdr;
> +
> +#define VIRTIO_CRYPTO_ALG_CHAIN_SESS_OP_SPEC_HDR_SIZE 16
> + /* fixed length fields, algo specific */
> + u8 algo_flf[VIRTIO_CRYPTO_ALG_CHAIN_SESS_OP_SPEC_HDR_SIZE];
> +
> + /* length of the additional authenticated data (AAD) in bytes */
> + le32 aad_len;
> + le32 padding;
> +};
> +
> +struct virtio_crypto_alg_chain_session_vlf {
> + /* Device read only portion */
> +
> + /* The cipher key */
> + u8 cipher_key[keylen];
> + /* The authenticated key */
> + u8 auth_key[auth_key_len];
> +};
> +\end{lstlisting}
> +
> +\field{hash_mode} decides the type used by \field{algo_flf}.
> +
> +\field{algo_flf} is fixed to 16 bytes and MUST contains or be one of
> +the following types:
> +\begin{itemize*}
> +\item struct virtio_crypto_hash_create_session_flf
> +\item struct virtio_crypto_mac_create_session_flf
> +\end{itemize*}
> +The data of unused part (if has) in \field{algo_flf} will be ignored.
> +
> +The length of \field{cipher_key} is specified in \field{keylen} in
> \field{cipher_hdr}.
> +
> +The length of \field{auth_key} is specified in \field{auth_key_len} in struct
> +virtio_crypto_mac_create_session_flf.
> +
> +The fixed-length parameters of Symmetric session requests are as follows:
> +
> +\begin{lstlisting}
> +struct virtio_crypto_sym_create_session_flf {
> + /* Device read only portion */
> +
> +#define VIRTIO_CRYPTO_SYM_SESS_OP_SPEC_HDR_SIZE 48
> + /* fixed length fields, opcode specific */
> + u8 op_flf[VIRTIO_CRYPTO_SYM_SESS_OP_SPEC_HDR_SIZE];
> +
> +/* No operation */
> +#define VIRTIO_CRYPTO_SYM_OP_NONE 0
> +/* Cipher only operation on the data */
> +#define VIRTIO_CRYPTO_SYM_OP_CIPHER 1
> +/* Chain any cipher with any hash or mac operation. The order
> + depends on the value of alg_chain_order param */
> +#define VIRTIO_CRYPTO_SYM_OP_ALGORITHM_CHAINING 2
> + le32 op_type;
> + le32 padding;
> +};
> +\end{lstlisting}
> +
> +\field{op_flf} is fixed to 48 bytes, MUST contains or be one of
> +the following types:
> +\begin{itemize*}
> +\item struct virtio_crypto_cipher_session_flf
> +\item struct virtio_crypto_alg_chain_session_flf
> +\end{itemize*}
> +The data of unused part (if has) in \field{op_flf} will be ignored.
> +
> +\field{op_type} decides the type used by \field{op_flf}.
> +
> +The variable-length parameters of Symmetric session requests are as follows:
> +
> +\begin{lstlisting}
> +struct virtio_crypto_sym_create_session_vlf {
> + /* Device read only portion */
> + /* variable length fields, opcode specific */
> + u8 op_vlf[vlf_len];
> +};
> +\end{lstlisting}
> +
> +\field{op_vlf} MUST contains or be one of the following types:
> +\begin{itemize*}
> +\item struct virtio_crypto_cipher_session_vlf
> +\item struct virtio_crypto_alg_chain_session_vlf
> +\end{itemize*}
> +
> +\field{op_type} in struct virtio_crypto_sym_create_session_flf decides the
> +type used by \field{op_vlf}.
> +
> +\field{vlf_len} is the size of the specific structure used.
> +
> +
> +\subparagraph{Session operation: AEAD session}\label{sec:Device Types /
> Crypto Device / Device
> +Operation / Control Virtqueue / Session operation / Session operation: AEAD
> session}
> +
> +The fixed-length and the variable-length parameters of AEAD session requests
> are as follows:
> +
> +\begin{lstlisting}
> +struct virtio_crypto_aead_create_session_flf {
> + /* Device read only portion */
> +
> + /* See VIRTIO_CRYPTO_AEAD_* above */
> + le32 algo;
> + /* length of key */
> + le32 key_len;
> + /* Authentication tag length */
> + le32 tag_len;
> + /* The length of the additional authenticated data (AAD) in bytes */
> + le32 aad_len;
> + /* encryption or decryption, See above VIRTIO_CRYPTO_OP_* */
> + le32 op;
> + le32 padding;
> +};
> +
> +struct virtio_crypto_aead_create_session_vlf {
> + /* Device read only portion */
> + u8 key[key_len];
> +};
> +\end{lstlisting}
> +
> +The length of \field{key} is specified in \field{key_len} in struct
> +virtio_crypto_aead_create_session_flf.
> +
> +
> +\drivernormative{\subparagraph}{Session operation: create session}{Device
> Types / Crypto Device / Device
> +Operation / Control Virtqueue / Session operation / Session operation:
> create session}
> +
> +\begin{itemize*}
> +\item The driver MUST set the \field{opcode} field based on service type:
> CIPHER, HASH, MAC, or AEAD.
> +\item The driver MUST set the control general header, the opcode specific
> header,
> + the opcode specific extra parameters and the opcode specific outcome
> buffer in turn.
> + See \ref{sec:Device Types / Crypto Device / Device Operation / Control
> Virtqueue}.
> +\item The driver MUST set the \field{reversed} field to zero.
> +\end{itemize*}
> +
> +\devicenormative{\subparagraph}{Session operation: create session}{Device
> Types / Crypto Device / Device
> +Operation / Control Virtqueue / Session operation / Session operation:
> create session}
> +
> +\begin{itemize*}
> +\item The device MUST use the corresponding opcode specific structure
> according to the
> + \field{opcode} in the control general header.
> +\item The device MUST extract extra parameters according to the structures
> used.
> +\item The device MUST set the \field{status} field to one of the following
> values of enum
> + VIRTIO_CRYPTO_STATUS after finish a session creation:
> +\begin{itemize*}
> +\item VIRTIO_CRYPTO_OK if a session is created successfully.
> +\item VIRTIO_CRYPTO_NOTSUPP if the requested algorithm or operation is
> unsupported.
> +\item VIRTIO_CRYPTO_NOSPC if no free session ID (only when the
> VIRTIO_CRYPTO_F_REVISION_1
> + feature bit is negotiated).
> +\item VIRTIO_CRYPTO_ERR if failure not mentioned above occurs.
> +\end{itemize*}
> +\item The device MUST set the \field{session_id} field to a unique session
> identifier only
> + if the status is set to VIRTIO_CRYPTO_OK.
> +\end{itemize*}
> +
> +\drivernormative{\subparagraph}{Session operation: destroy session}{Device
> Types / Crypto Device / Device
> +Operation / Control Virtqueue / Session operation / Session operation:
> destroy session}
> +
> +\begin{itemize*}
> +\item The driver MUST set the \field{opcode} field based on service type:
> CIPHER, HASH, MAC, or AEAD.
> +\item The driver MUST set the \field{session_id} to a valid value assigned
> by the device
> + when the session was created.
> +\end{itemize*}
> +
> +\devicenormative{\subparagraph}{Session operation: destroy session}{Device
> Types / Crypto Device / Device
> +Operation / Control Virtqueue / Session operation / Session operation:
> destroy session}
> +
> +\begin{itemize*}
> +\item The device MUST set the \field{status} field to one of the following
> values of enum VIRTIO_CRYPTO_STATUS.
> +\begin{itemize*}
> +\item VIRTIO_CRYPTO_OK if a session is created successfully.
> +\item VIRTIO_CRYPTO_ERR if any failure occurs.
> +\end{itemize*}
> +\end{itemize*}
> +
> +
> +\subsubsection{Data Virtqueue}\label{sec:Device Types / Crypto Device /
> Device Operation / Data Virtqueue}
> +
> +The driver uses the data virtqueues to transmit crypto operation requests to
> the device,
> +and completes the crypto operations.
> +
> +The header for dataq is as follows:
> +
> +\begin{lstlisting}
> +struct virtio_crypto_op_header {
> +#define VIRTIO_CRYPTO_CIPHER_ENCRYPT \
> + VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_CIPHER, 0x00)
> +#define VIRTIO_CRYPTO_CIPHER_DECRYPT \
> + VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_CIPHER, 0x01)
> +#define VIRTIO_CRYPTO_HASH \
> + VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_HASH, 0x00)
> +#define VIRTIO_CRYPTO_MAC \
> + VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_MAC, 0x00)
> +#define VIRTIO_CRYPTO_AEAD_ENCRYPT \
> + VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_AEAD, 0x00)
> +#define VIRTIO_CRYPTO_AEAD_DECRYPT \
> + VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_AEAD, 0x01)
> + le32 opcode;
> + /* algo should be service-specific algorithms */
> + le32 algo;
> + le64 session_id;
> +#define VIRTIO_CRYPTO_FLAG_SESSION_MODE 1
> + /* control flag to control the request */
> + le32 flag;
> + le32 padding;
> +};
> +\end{lstlisting}
> +
> +\begin{note}
> +If VIRTIO_CRYPTO_F_REVISION_1 is negotiated but
> VIRTIO_CRYPTO_F_<SERVICE>_STATELESS_MODE
> +is not negotiated then <SERVICE> retuqests with the \field{flag} (in struct
s/retuqests/requests
> +virtio_crypto_op_header) is ZERO need to be rejected. If
> VIRTIO_CRYPTO_F_REVISION_1 is
> +not negotiated the \field{flag} is ignored.
> +\end{note}
> +
I think your formulation is a bit hard to understand.
I would prefer:
+\begin{note}
+If VIRTIO_CRYPTO_F_REVISION_1 is not negotiated the \field{flag} is ignored.
+
+If VIRTIO_CRYPTO_F_REVISION_1 is negotiated but
VIRTIO_CRYPTO_F_<SERVICE>_STATELESS_MODE
+is not negotiated, then the device should reject <SERVICE> requests if
+VIRTIO_CRYPTO_FLAG_SESSION_MODE is not set (in \field{flag}).
+\end{note}
+
> +The dataq request is composed of four parts:
> +\begin{lstlisting}
> +struct virtio_crypto_op_data_req {
> + /* Device read only portion */
> +
> + struct virtio_crypto_op_header header;
> +
> +#define VIRTIO_CRYPTO_DATAQ_OP_SPEC_HDR_LEGACY 48
> + /* fixed length fields, opcode specific */
> + u8 op_flf[flf_len];
> +
> + /* Device read && write portion */
> + /* variable length fields, opcode specific */
> + u8 op_vlf[vlf_len];
Descriptors are either read or write. You need read && write (whatever the
sematic is) because you throw things together that don't belong together.
I would try to do the same as for the ctrl requests:
+ * Device write only portion */
+ u8 op_outcome;
and describe the outcome on a per service basis. Also see my
comments about the dst_data_len below.
> +
> + /* Device write only portion */
> + struct virtio_crypto_inhdr inhdr;
> +};
> +\end{lstlisting}
> +
> +\field{header} is a general header (see above).
> +
> +\field{op_flf} is the opcode (in \field{header}) specific header.
> +
> +\field{flf_len} depends on the VIRTIO_CRYPTO_F_REVISION_1 feature bit
> +(see below).
> +
> +\field{op_vlf} is the opcode (in \field{header}) specific parameters.
> +
> +\field{vlf_len} is the size of the specific structure used.
> +
> +\begin{itemize*}
> +\item If the the opcode (in \field{header}) is VIRTIO_CRYPTO_CIPHER_ENCRYPT
> + or VIRTIO_CRYPTO_CIPHER_DECRYPT then:
> + \begin{itemize*}
> + \item If VIRTIO_CRYPTO_F_CIPHER_STATELESS_MODE is negotiated,
> \field{op_flf} is
> + struct virtio_crypto_sym_data_flf_stateless, and \field{op_vlf} is
> struct
> + virtio_crypto_sym_data_vlf_stateless.
What does this _data_ (in the name) symbolise?
> + \item If VIRTIO_CRYPTO_F_CIPHER_STATELESS_MODE is NOT negotiated,
> \field{op_flf}
> + is struct virtio_crypto_sym_data_flf if VIRTIO_CRYPTO_F_REVISION_1
> is negotiated
> + and struct virtio_crypto_sym_data_flf if padded to 48 bytes if NOT
> negotiated,
> + and \field{op_vlf} is struct virtio_crypto_sym_data_vlf.
> + \end{itemize*}
> +\item If the the opcode (in \field{header}) is VIRTIO_CRYPTO_HASH:
> + \begin{itemize*}
> + \item If VIRTIO_CRYPTO_F_HASH_STATELESS_MODE is negotiated,
> \field{op_flf} is
> + struct virtio_crypto_hash_data_flf_stateless, and \field{op_vlf} is
> struct
> + virtio_crypto_hash_data_vlf_stateless.
> + \item If VIRTIO_CRYPTO_F_HASH_STATELESS_MODE is NOT negotiated,
> \field{op_flf}
> + is struct virtio_crypto_hash_data_flf if VIRTIO_CRYPTO_F_REVISION_1
> is negotiated
> + and struct virtio_crypto_hash_data_flf if padded to 48 bytes if NOT
> negotiated,
> + and \field{op_vlf} is struct virtio_crypto_hash_data_vlf.
> +\item If the the opcode (in \field{header}) is VIRTIO_CRYPTO_MAC:
> + \begin{itemize*}
> + \item If VIRTIO_CRYPTO_F_MAC_STATELESS_MODE is negotiated,
> \field{op_flf} is
> + struct virtio_crypto_mac_data_flf_stateless, and \field{op_vlf} is
> struct
> + virtio_crypto_mac_data_vlf_stateless.
> + \item If VIRTIO_CRYPTO_F_MAC_STATELESS_MODE is NOT negotiated,
> \field{op_flf}
> + is struct virtio_crypto_mac_data_flf if VIRTIO_CRYPTO_F_REVISION_1
> is negotiated
> + and struct virtio_crypto_mac_data_flf if padded to 48 bytes if NOT
> negotiated,
> + and \field{op_vlf} is struct virtio_crypto_mac_data_vlf.
> +\item If the the opcode (in \field{header}) is VIRTIO_CRYPTO_AEAD_ENCRYPT
> + or VIRTIO_CRYPTO_AEAD_DECRYPT then:
> + \begin{itemize*}
> + \item If VIRTIO_CRYPTO_F_AEAD_STATELESS_MODE is negotiated,
> \field{op_flf} is
> + struct virtio_crypto_aead_data_flf_stateless, and \field{op_vlf} is
> struct
> + virtio_crypto_aead_data_vlf_stateless.
> + \item If VIRTIO_CRYPTO_F_AEAD_STATELESS_MODE is NOT negotiated,
> \field{op_flf}
> + is struct virtio_crypto_aead_data_flf if VIRTIO_CRYPTO_F_REVISION_1
> is negotiated
> + and struct virtio_crypto_aead_data_flf if padded to 48 bytes if NOT
> negotiated,
> + and \field{op_vlf} is struct virtio_crypto_aead_data_vlf.
> +\end{itemize*}
> +
> +\field{inhdr} is a unified input header that used to return the status of
> +the operations, is defined as follows:
> +
> +\begin{lstlisting}
> +struct virtio_crypto_inhdr {
> + u8 status;
> +};
> +\end{lstlisting}
> +
> +\subsubsection{HASH Service Operation}\label{sec:Device Types / Crypto
> Device / Device Operation / HASH Service Operation}
> +
> +Session mode HASH service requests are as follows:
> +
> +\begin{lstlisting}
> +struct virtio_crypto_hash_data_flf {
> + /* length of source data */
> + le32 src_data_len;
> + /* hash result length */
> + le32 hash_result_len;
> +};
> +
> +struct virtio_crypto_hash_data_vlf {
> + /* Device read only portion */
> + /* Source data */
> + u8 src_data[src_data_len];
> +
> + /* Device write only portion */
> + /* Hash result data */
> + u8 hash_result[hash_result_len];
> +};
> +\end{lstlisting}
> +
> +Each data request uses the virtio_crypto_hash_data_flf structure and the
> +virtio_crypto_hash_data_vlfto structure to store information used to run the
> +HASH operations.
> +
> +\field{src_data} is the source data that will be processed.
> +\field{src_data_len} is the length of source data.
> +\field{hash_result} is the result data and \field{hash_result_len} is the
> length
> +of it.
> +
> +Stateless mode HASH service requests are as follows:
> +
> +\begin{lstlisting}
> +struct virtio_crypto_hash_data_flf_stateless {
> + struct {
> + /* See VIRTIO_CRYPTO_HASH_* above */
> + le32 algo;
> + } sess_para;
> +
> + /* length of source data */
> + le32 src_data_len;
> + /* hash result length */
> + le32 hash_result_len;
> + le32 reserved;
> +};
> +struct virtio_crypto_hash_data_vlf_stateless {
> + /* Device read only portion */
> + /* Source data */
> + u8 src_data[src_data_len];
> +
> + /* Device write only portion */
> + /* Hash result data */
> + u8 hash_result[hash_result_len];
> +};
> +\end{lstlisting}
> +
> +\drivernormative{\paragraph}{HASH Service Operation}{Device Types / Crypto
> Device / Device Operation / HASH Service Operation}
> +
> +\begin{itemize*}
> +\item If the driver uses the session mode, then the driver MUST set
> \field{session_id}
> + in struct virtio_crypto_op_header to a valid value assigned by the
> device when the
> + session was created.
> +\item If the VIRTIO_CRYPTO_F_HASH_STATELESS_MODE feature bit is negotiated,
> 1) if the
> + driver uses the stateless mode, then the driver MUST set the
> \field{flag} field in
> + struct virtio_crypto_op_header to ZERO and MUST set the fields in struct
> + virtio_crypto_hash_data_flf_stateless.sess_para, 2) if the driver uses
> the session
> + mode, then the driver MUST set the \field{flag} field in struct
> virtio_crypto_op_header
> + to VIRTIO_CRYPTO_FLAG_SESSION_MODE.
> +\item The driver MUST set \field{opcode} in struct virtio_crypto_op_header
> to VIRTIO_CRYPTO_HASH.
> +\end{itemize*}
> +
> +\devicenormative{\paragraph}{HASH Service Operation}{Device Types / Crypto
> Device / Device Operation / HASH Service Operation}
> +
> +\begin{itemize*}
> +\item The device MUST use the corresponding structure according to the
> \field{opcode}
> + in the data general header.
> +\item If the VIRTIO_CRYPTO_F_HASH_STATELESS_MODE feature bit is negotiated,
> the device
> + MUST parse \field{flag} field in struct virtio_crypto_op_header in order
> to decide
> + which mode the driver uses.
> +\item The device MUST copy the results of HASH operations in the
> hash_result[] if HASH
> + operations success.
> +\item The device MUST set \field{status} in struct virtio_crypto_inhdr to
> one of the
> + following values of enum VIRTIO_CRYPTO_STATUS:
> +\begin{itemize*}
> +\item VIRTIO_CRYPTO_OK if the operation success.
> +\item VIRTIO_CRYPTO_NOTSUPP if the requested algorithm or operation is
> unsupported.
> +\item VIRTIO_CRYPTO_INVSESS if the session ID invalid when in session mode.
> +\item VIRTIO_CRYPTO_ERR if any failure not mentioned above occurs.
> +\end{itemize*}
> +\end{itemize*}
> +
> +
> +\subsubsection{MAC Service Operation}\label{sec:Device Types / Crypto Device
> / Device Operation / MAC Service Operation}
> +
> +Session mode MAC service requests are as follows:
> +
> +\begin{lstlisting}
> +struct virtio_crypto_mac_data_flf {
> + struct virtio_crypto_hash_data_flf hdr;
> +};
> +
> +struct virtio_crypto_mac_data_vlf {
> + /* Device read only portion */
> + /* Source data */
> + u8 src_data[src_data_len];
> +
> + /* Device write only portion */
> + /* Hash result data */
> + u8 hash_result[hash_result_len];
> +};
> +\end{lstlisting}
> +
> +Each request uses the virtio_crypto_mac_data_flf structure and the
> +virtio_crypto_mac_data_vlf structure to store information used to run the
> +MAC operations.
> +
> +\field{src_data} is the source data that will be processed.
> +\field{src_data_len} is the length of source data.
> +\field{hash_result} is the result data and \field{hash_result_len} is the
> length
> +of it.
> +
> +Stateless mode MAC service requests are as follows:
> +
> +\begin{lstlisting}
> +struct virtio_crypto_mac_data_flf_stateless {
> + struct {
> + /* See VIRTIO_CRYPTO_MAC_* above */
> + le32 algo;
> + /* length of authenticated key */
> + le32 auth_key_len;
> + } sess_para;
> +
> + /* length of source data */
> + le32 src_data_len;
> + /* hash result length */
> + le32 hash_result_len;
> +};
> +
> +struct virtio_crypto_mac_data_vlf_stateless {
> + /* Device read only portion */
> + /* The authenticated key */
> + u8 auth_key[auth_key_len];
> + /* Source data */
> + u8 src_data[src_data_len];
> +
> + /* Device write only portion */
> + /* Hash result data */
> + u8 hash_result[hash_result_len];
> +};
> +\end{lstlisting}
> +
> +\field{auth_key} is the authenticated key that will be used during the
> process.
> +\field{auth_key_len} is the length of the key.
> +
> +\drivernormative{\paragraph}{MAC Service Operation}{Device Types / Crypto
> Device / Device Operation / MAC Service Operation}
> +
> +\begin{itemize*}
> +\item If the driver uses the session mode, then the driver MUST set
> \field{session_id}
> + in struct virtio_crypto_op_header to a valid value assigned by the
> device when the
> + session was created.
> +\item If the VIRTIO_CRYPTO_F_MAC_STATELESS_MODE feature bit is negotiated,
> 1) if the
> + driver uses the stateless mode, then the driver MUST set the
> \field{flag} field
> + in struct virtio_crypto_op_header to ZERO and MUST set the fields in
> struct
> + virtio_crypto_mac_data_flf_stateless.sess_para, 2) if the driver uses
> the session
> + mode, then the driver MUST set the \field{flag} field in struct
> virtio_crypto_op_header
> + to VIRTIO_CRYPTO_FLAG_SESSION_MODE.
> +\item The driver MUST set \field{opcode} in struct virtio_crypto_op_header
> to VIRTIO_CRYPTO_MAC.
> +\end{itemize*}
> +
> +\devicenormative{\paragraph}{MAC Service Operation}{Device Types / Crypto
> Device / Device Operation / MAC Service Operation}
> +
> +\begin{itemize*}
> +\item If the VIRTIO_CRYPTO_F_MAC_STATELESS_MODE feature bit is negotiated,
> the device
> + MUST parse \field{flag} field in struct virtio_crypto_op_header in order
> to decide
> + which mode the driver uses.
> +\item The device MUST copy the results of MAC operations in the
> hash_result[] if HASH
> + operations success.
> +\item The device MUST set \field{status} in struct virtio_crypto_inhdr to
> one of the
> + following values of enum VIRTIO_CRYPTO_STATUS:
> +\begin{itemize*}
> +\item VIRTIO_CRYPTO_OK if the operation success.
> +\item VIRTIO_CRYPTO_NOTSUPP if the requested algorithm or operation is
> unsupported.
> +\item VIRTIO_CRYPTO_INVSESS if the session ID invalid when in session mode.
> +\item VIRTIO_CRYPTO_ERR if any failure not mentioned above occurs.
> +\end{itemize*}
> +\end{itemize*}
> +
> +\subsubsection{Symmetric algorithms Operation}\label{sec:Device Types /
> Crypto Device / Device Operation / Symmetric algorithms Operation}
> +
> +Session mode CIPHER service requests are as follows:
> +
> +\begin{lstlisting}
> +struct virtio_crypto_cipher_data_flf {
> + /*
> + * Byte Length of valid IV/Counter data pointed to by the below iv data.
> + *
> + * For block ciphers in CBC or F8 mode, or for Kasumi in F8 mode, or for
> + * SNOW3G in UEA2 mode, this is the length of the IV (which
> + * must be the same as the block length of the cipher).
> + * For block ciphers in CTR mode, this is the length of the counter
> + * (which must be the same as the block length of the cipher).
> + */
> + le32 iv_len;
> + /* length of source data */
> + le32 src_data_len;
> + /* length of destination data */
> + le32 dst_data_len;
> + le32 padding;
> +};
> +
> +struct virtio_crypto_cipher_data_vlf {
> + /* Device read only portion */
> +
> + /*
> + * Initialization Vector or Counter data.
> + *
> + * For block ciphers in CBC or F8 mode, or for Kasumi in F8 mode, or for
> + * SNOW3G in UEA2 mode, this is the Initialization Vector (IV)
> + * value.
> + * For block ciphers in CTR mode, this is the counter.
> + * For AES-XTS, this is the 128bit tweak, i, from IEEE Std 1619-2007.
> + *
> + * The IV/Counter will be updated after every partial cryptographic
> + * operation.
> + */
> + u8 iv[iv_len];
> + /* Source data */
> + u8 src_data[src_data_len];
> +
> + /* Device write only portion */
> + /* Destination data */
> + u8 dst_data[dst_data_len];
I'm a bit puzzled about dst_data_len. I'm by no means a crypto expert,
and that is probably the very reason of my discomfort.
I've tried to figure out how dst_data_len is used and expected to find
a place that checks, that at least a sufficiently large buffer was provided.
I've also assumed that the src_data_len is likely to imply the dst_data_len
for any given algorithm. Furthermore, I even hypothesised that the both
lengths are the same. All based on what I remember about block ciphers.
If that hypothesis is right, then I don't understand why do we need
both src_data_len and dst_data_len.
Since dst_data_len is device read only, the driver I figure the driver
needs to know the exact length (since I cant figure out, based on this
spec, how is it supposed to be told by the device which part of the
buffer is the result and which part garbage). So the only sane usage
I was able to come up with is to avoid the device overwritting other
parts of the requests device writtable part because of a driver
bug (wrong dst_data_len). But as I've said I could not find the corresponding
code in qemu.
Anyway providing some more background for the guys only superficially
involved with crypto (like me) would be appreciated.
I will stop here for now. I read the rest real quick and I did not
see anything major. I think we are slowly getting there.
Regards,
Halil
