From patchwork Wed Jan 4 10:03:04 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gonglei (Arei)" X-Patchwork-Id: 9496385 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id D2D4C606A9 for ; Wed, 4 Jan 2017 10:05:07 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B733320223 for ; Wed, 4 Jan 2017 10:05:07 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A815227D9B; Wed, 4 Jan 2017 10:05:07 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 137D020223 for ; Wed, 4 Jan 2017 10:05:05 +0000 (UTC) Received: from localhost ([::1]:38240 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cOiRM-0000Sj-8O for patchwork-qemu-devel@patchwork.kernel.org; Wed, 04 Jan 2017 05:05:04 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35819) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cOiQo-0000P6-Qz for qemu-devel@nongnu.org; Wed, 04 Jan 2017 05:04:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cOiQk-0006do-93 for qemu-devel@nongnu.org; Wed, 04 Jan 2017 05:04:30 -0500 Received: from szxga03-in.huawei.com ([119.145.14.66]:13937) by eggs.gnu.org with esmtps (TLS1.0:RSA_ARCFOUR_SHA1:16) (Exim 4.71) (envelope-from ) id 1cOiQi-0006VC-A8 for qemu-devel@nongnu.org; Wed, 04 Jan 2017 05:04:26 -0500 Received: from 172.24.1.36 (EHLO szxeml426-hub.china.huawei.com) ([172.24.1.36]) by szxrg03-dlp.huawei.com (MOS 4.4.3-GA FastPath queued) with ESMTP id CNO34866; Wed, 04 Jan 2017 18:03:24 +0800 (CST) Received: from localhost (10.177.18.62) by szxeml426-hub.china.huawei.com (10.82.67.181) with Microsoft SMTP Server id 14.3.235.1; Wed, 4 Jan 2017 18:03:13 +0800 From: Gonglei To: , Date: Wed, 4 Jan 2017 18:03:04 +0800 Message-ID: <1483524185-9036-2-git-send-email-arei.gonglei@huawei.com> X-Mailer: git-send-email 2.8.2.windows.1 In-Reply-To: <1483524185-9036-1-git-send-email-arei.gonglei@huawei.com> References: <1483524185-9036-1-git-send-email-arei.gonglei@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.177.18.62] X-CFilter-Loop: Reflected X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4.x-2.6.x [generic] [fuzzy] X-Received-From: 119.145.14.66 Subject: [Qemu-devel] [PATCH v15 1/2] virtio-crypto: Add virtio crypto device specification X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: weidong.huang@huawei.com, mst@redhat.com, john.griffin@intel.com, cornelia.huck@de.ibm.com, jianjay.zhou@huawei.com, Varun.Sethi@freescale.com, denglingli@chinamobile.com, arei.gonglei@hotmail.com, Hanweidong , agraf@suse.de, Gonglei , nmorey@kalray.eu, vincent.jardin@6wind.com, Ola.Liljedahl@arm.com, luonengjun@huawei.com, xin.zeng@intel.com, liang.j.ma@intel.com, stefanha@redhat.com, Shiqing.Fan@huawei.com, Jani.Kokkonen@huawei.com, pasic@linux.vnet.ibm.com, brian.a.keating@intel.com, claudio.fontana@huawei.com, mike.caraman@nxp.com, wu.wubin@huawei.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP 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 CC: Michael S. Tsirkin CC: Cornelia Huck CC: Stefan Hajnoczi CC: Lingli Deng CC: Jani Kokkonen CC: Ola Liljedahl CC: Varun Sethi CC: Zeng Xin CC: Keating Brian CC: Ma Liang J CC: Griffin John CC: Hanweidong CC: Mihai Claudiu Caraman --- content.tex | 2 + virtio-crypto.tex | 1029 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 1031 insertions(+) create mode 100644 virtio-crypto.tex diff --git a/content.tex b/content.tex index 4b45678..ab75f78 100644 --- a/content.tex +++ b/content.tex @@ -5750,6 +5750,8 @@ 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 there are three device-independent feature bits defined: diff --git a/virtio-crypto.tex b/virtio-crypto.tex new file mode 100644 index 0000000..44819f9 --- /dev/null +++ b/virtio-crypto.tex @@ -0,0 +1,1029 @@ +\section{Crypto Device}\label{sec:Device Types / Crypto Device} + +The virtio crypto device is a virtual cryptography device as well as a kind of +virtual hardware accelerator for virtual machines. The encryption and +decryption requests are placed in any of teh data active queues and are ultimately handled by the +backend crypto accelerators. The second kind of queue is the control queue used to create +or destroy sessions for symmetric algorithms and will control some advanced +features in the future. The virtio crypto device provides the following crypto +services: CIPHER, MAC, HASH, and AEAD. + + +\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} + +VIRTIO_CRYPTO_F_CIPHER_SESSION_MODE (1) Session mode is available for CIPHER service. +VIRTIO_CRYPTO_F_HASH_SESSION_MODE (2) Session mode is available for HASH service. +VIRTIO_CRYPTO_F_MAC_SESSION_MODE (3) Session mode is available for MAC service. +VIRTIO_CRYPTO_F_AEAD_SESSION_MODE (4) Session mode is available for AEAD service. + +\subsection{Device configuration layout}\label{sec:Device Types / Crypto Device / Device configuration layout} + +The following driver-read-only configuration fields are defined: + +\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 */ + le32 max_cipher_key_len; + /* Maximum length of authenticated key */ + le32 max_auth_key_len; + le32 reserve; + /* Maximum size of each crypto request's content */ + le64 max_size; +}; +\end{lstlisting} + +The value of the \field{status} field is VIRTIO_CRYPTO_S_HW_READY or ~VIRTIO_CRYPTO_S_HW_READY. + +\begin{lstlisting} +#define VIRTIO_CRYPTO_S_HW_READY (1 << 0) +\end{lstlisting} + +The VIRTIO_CRYPTO_S_HW_READY flag is used to show whether the hardware is ready to work or not. + +The following driver-read-only fields include \field{max_dataqueues}, which specifies the +maximum number of data virtqueues (dataq1\ldots dataqN), and \field{crypto_services}, +which indicates the crypto services the virtio crypto supports. + +The following 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 last driver-read-only fields specify detailed algorithms masks +the device offers for corresponding 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 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 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 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} + +\begin{note} +Any other value is reserved for future use. +\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 \field{status} based on the status of the hardware-backed implementation. +\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 based on the \field{crypto_services} field. +\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 ready \field{status} from the bottom bit of status to check whether the hardware-backed + implementation is ready or not, and the driver MUST reread it after the device reset. +\item The driver MUST NOT transmit any packets to the device if the ready \field{status} 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 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*} + +\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 identify and initialize the control virtqueue. +\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*} + +\devicenormative{\subsubsection}{Device Initialization}{Device Types / Crypto Device / Device Initialization} + +\begin{itemize*} +\item The device MUST be configured with at least one accelerator which executes backend crypto operations. +\item The device MUST write the \field{crypto_services} field based on the capacities of the backend accelerator. +\end{itemize*} + +\subsection{Device Operation}\label{sec:Device Types / Crypto Device / Device Operation} + +Packets can be transmitted by placing them in both the controlq and dataq. +Packets consist of a general header and a service-specific request. +Where 'general header' is for all crypto requests, and 'service specific requests' +are composed of operation parameter + output data + input data in general. +Operation parameters are algorithm-specific parameters, output data is the +data that should be utilized in operations, and input data is equal to +"operation result + result data". + +The device can support both session mode (See \ref{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue / Session operation}) and non-session mode, for example, +As VIRTIO_CRYPTO_F_CIPHER_SESSION feature bit is negotiated, the driver can use session mode for CIPHER service, otherwise it can only use non-session mode. + +\begin{note} +The basic unit of all data length the byte. +\end{note} + +The general header for controlq is as follows: + +\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; + le32 algo; + le32 flag; + /* data virtqueue id */ + le32 queue_id; +}; +\end{lstlisting} + +The general header of dataq: + +\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; + /* session_id should be service-specific algorithms */ + le64 session_id; +#define VIRTIO_CRYPTO_FLAG_SESSION_MODE 1 +#define VIRTIO_CRYPTO_FLAG_NONE_SESSION_MODE 2 + /* control flag to control the request */ + le32 flag; + le32 padding; +}; +\end{lstlisting} + +The device can set the operation status as follows: VIRTIO_CRYPTO_OK: success; +VIRTIO_CRYPTO_ERR: failure or device error; VIRTIO_CRYPTO_NOTSUPP: not supported; +VIRTIO_CRYPTO_INVSESS: invalid session ID when executing crypto operations. + +\begin{lstlisting} +enum VIRITO_CRYPTO_STATUS { + VIRTIO_CRYPTO_OK = 0, + VIRTIO_CRYPTO_ERR = 1, + VIRTIO_CRYPTO_BADMSG = 2, + VIRTIO_CRYPTO_NOTSUPP = 3, + VIRTIO_CRYPTO_INVSESS = 4, + VIRTIO_CRYPTO_MAX +}; +\end{lstlisting} + +\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 which handles the non-data plane operations, such as session +operations (See \ref{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue / Session operation}). + +The packet of controlq: + +\begin{lstlisting} +struct virtio_crypto_op_ctrl_req { + struct virtio_crypto_ctrl_header header; + + union { + struct virtio_crypto_sym_create_session_req sym_create_session; + struct virtio_crypto_hash_create_session_req hash_create_session; + struct virtio_crypto_mac_create_session_req mac_create_session; + struct virtio_crypto_aead_create_session_req aead_create_session; + struct virtio_crypto_destroy_session_req destroy_session; + } u; +}; +\end{lstlisting} + +The header is the general header, and the union is of the algorithm-specific type, +which is set by the driver. All the properties in the union are shown as follows. + +\paragraph{Session operation}\label{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue / Session operation} + +The symmetric algorithms involve the concept of sessions. A session is a +handle which describes the cryptographic parameters to be applied to +a number of buffers. The data within a session handle includes the following: + +\begin{enumerate} +\item The operation (CIPHER, HASH/MAC or both, and if both, the order in + which the algorithms should be applied). +\item The CIPHER set data, including the CIPHER algorithm and mode, + the key and its length, and the direction (encryption or decryption). +\item The HASH/MAC set data, including the HASH algorithm or MAC algorithm, + and hash result length (to allow for truncation). +\begin{itemize*} +\item Authenticated mode can refer to MAC, which requires that the key and + its length are also specified. +\item For nested mode, the inner and outer prefix data and length are specified, + as well as the outer HASH algorithm. +\end{itemize*} +\end{enumerate} + +The following structure stores the result of session creation set by the device: + +\begin{lstlisting} +struct virtio_crypto_session_input { + /* Device-writable part */ + 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_req { + /* Device-readable part */ + le64 session_id; + /* Device-writable part */ + 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 packet of HASH session is as follows: + +\begin{lstlisting} +struct virtio_crypto_hash_session_para { + /* See VIRTIO_CRYPTO_HASH_* above */ + le32 algo; + /* hash result length */ + le32 hash_result_len; +}; +struct virtio_crypto_hash_create_session_req { + /* Device-readable part */ + struct virtio_crypto_hash_session_para para; + /* Device-writable part */ + struct virtio_crypto_session_input input; +}; +\end{lstlisting} + +\subparagraph{Session operation: MAC session}\label{sec:Device Types / Crypto Device / Device +Operation / Control Virtqueue / Session operation / Session operation: MAC session} + +The packet of MAC session is as follows: + +\begin{lstlisting} +struct virtio_crypto_mac_session_para { + /* 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_req { + /* Device-readable part */ + struct virtio_crypto_mac_session_para para; + /* The authenticated key */ + u8 auth_key[auth_key_len]; + + /* Device-writable part */ + struct virtio_crypto_session_input input; +}; +\end{lstlisting} + +\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 includes two parts, CIPHER algorithms and chain +algorithms (chaining CIPHER and HASH/MAC). The packet for CIPHER session is as follows: + +\begin{lstlisting} +struct virtio_crypto_cipher_session_para { + /* 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_req { + /* Device-readable part */ + struct virtio_crypto_cipher_session_para para; + /* The cipher key */ + u8 cipher_key[keylen]; + + /* Device-writable part */ + struct virtio_crypto_session_input input; +}; +\end{lstlisting} + +The packet for algorithm chaining is as follows: + +\begin{lstlisting} +struct virtio_crypto_alg_chain_session_para { +#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_para cipher_param; + union { + struct virtio_crypto_hash_session_para hash_param; + struct virtio_crypto_mac_session_para mac_param; + } u; + /* length of the additional authenticated data (AAD) in bytes */ + le32 aad_len; + le32 padding; +}; + +struct virtio_crypto_alg_chain_session_req { + /* Device-readable part */ + struct virtio_crypto_alg_chain_session_para para; + /* The cipher key */ + u8 cipher_key[keylen]; + /* The authenticated key */ + u8 auth_key[auth_key_len]; + + /* Device-writable part */ + struct virtio_crypto_session_input input; +}; +\end{lstlisting} + +The packet for symmetric algorithm is as follows: + +\begin{lstlisting} +struct virtio_crypto_sym_create_session_req { + union { + struct virtio_crypto_cipher_session_req cipher; + struct virtio_crypto_alg_chain_session_req chain; + } u; + + /* Device-readable part */ + +/* 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} + +\subparagraph{Session operation: AEAD session}\label{sec:Device Types / Crypto Device / Device +Operation / Control Virtqueue / Session operation / Session operation: AEAD session} + +The packet for AEAD session is as follows: + +\begin{lstlisting} +struct virtio_crypto_aead_session_para { + /* 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_req { + /* Device-readable part */ + struct virtio_crypto_aead_session_para para; + u8 key[key_len]; + + /* Device-writeable part */ + struct virtio_crypto_session_input input; +}; +\end{lstlisting} + +\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 control general header and corresponding properties of the union in structure virtio_crypto_op_ctrl_req. See \ref{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue}. +\item The driver MUST set \field{opcode} field based on service type: CIPHER, HASH, MAC, or AEAD. +\item The driver MUST set \field{queue_id} field to show used dataq. +\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 set \field{session_id} field as a session identifier return to the driver when the device finishes processing session creation. +\item The device MUST set \field{status} field to one of the values of enum VIRITO_CRYPTO_STATUS. +\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 \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 which assigned by the device when a session is 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 \field{status} field to one of the values of enum VIRITO_CRYPTO_STATUS. +\end{itemize*} + +\subsubsection{Data Virtqueue}\label{sec:Device Types / Crypto Device / Device Operation / Data Virtqueue} + +The driver uses the data virtqueue to transmit the requests of crypto operation to the device, +and completes the data plane operations (such as crypto operation). + +The packet of dataq is as follows: + +\begin{lstlisting} +struct virtio_crypto_op_data_req { + struct virtio_crypto_op_header header; + + union { + struct virtio_crypto_sym_data_req sym_req; + struct virtio_crypto_hash_data_req hash_req; + struct virtio_crypto_mac_data_req mac_req; + struct virtio_crypto_aead_data_req aead_req; + } u; +}; +\end{lstlisting} + +The header is the general header and the union is of the algorithm-specific type, +which is set by the driver. All properties in the union are shown as follows. + +There is a unified input header structure for all crypto services. + +The structure 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} + +\begin{lstlisting} +struct virtio_crypto_hash_para { + 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_req { + /* Device-readable part */ + struct virtio_crypto_hash_para para; + /* Source data */ + u8 src_data[src_data_len]; + + /* Device-writable part */ + /* Hash result data */ + u8 hash_result[hash_result_len]; + struct virtio_crypto_inhdr inhdr; +}; +\end{lstlisting} + +Each data request uses virtio_crypto_hash_data_req structure to store information +used to run the HASH operations. + +The information includes the hash parameters stored by \field{para}, output data and input data. +The output data here includes the source data and the input data includes the hash result data used to save the results of the HASH operations. +\field{inhdr} stores status of executing the HASH operations. + +\drivernormative{\paragraph}{HASH Service Operation}{Device Types / Crypto Device / Device Operation / HASH Service Operation} + +\begin{itemize*} +\item If the VIRTIO_CRYPTO_F_HASH_SESSION_MODE feature bit is negotiated and the driver uses the session mode, then the driver MUST set the \field{session_id} in struct virtio_crypto_op_header + to a valid value which assigned by the device when a session is created and MUST set \field{flag} field to VIRTIO_CRYPTO_FLAG_SESSION_MODE. +\item If the VIRTIO_CRYPTO_F_HASH_SESSION_MODE feature bit is not negotiated or the driver doesn't use the session mode, then the driver MUST set \field{flag} field in struct virtio_crypto_op_header + to VIRTIO_CRYPTO_FLAG_SESSION_NONE_MODE and MUST set fields in struct virtio_crypto_hash_para.sess_para. +\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 copy the results of HASH operations to the hash_result[] if HASH operations success. +\item The device MUST set \field{status} in struct virtio_crypto_inhdr to one of the values of enum VIRITO_CRYPTO_STATUS. +\end{itemize*} + +\subsubsection{MAC Service Operation}\label{sec:Device Types / Crypto Device / Device Operation / MAC Service Operation} + +\begin{lstlisting} +struct virtio_crypto_mac_para { + 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_req { + /* Device-readable part */ + struct virtio_crypto_mac_para para; + /* The authenticated key */ + u8 auth_key[auth_key_len]; + /* Source data */ + u8 src_data[src_data_len]; + + /* Device-writable part */ + /* Hash result data */ + u8 hash_result[hash_result_len]; + struct virtio_crypto_inhdr inhdr; +}; +\end{lstlisting} + +Each data request uses virtio_crypto_mac_data_req structure to store information +used to run the MAC operations. + +The information includes the hash parameters stored by \field{para}, output data and input data. +The output data here includes the source data and the input data includes the hash result data used to save the results of the MAC operations. +\field{inhdr} stores status of executing the MAC operations. + +\drivernormative{\paragraph}{MAC Service Operation}{Device Types / Crypto Device / Device Operation / MAC Service Operation} + +\begin{itemize*} +\item If the VIRTIO_CRYPTO_F_MAC_SESSION_MODE feature bit is negotiated and the driver uses the session mode, then the driver MUST set the \field{session_id} in struct virtio_crypto_op_header + to a valid value which assigned by the device when a session is created and MUST set \field{flag} field to VIRTIO_CRYPTO_FLAG_SESSION_MODE. +\item If the VIRTIO_CRYPTO_F_MAC_SESSION_MODE feature bit is not negotiated or the driver doesn't use the session mode, then the driver MUST set \field{flag} field in struct virtio_crypto_op_header + to VIRTIO_CRYPTO_FLAG_SESSION_NONE_MODE and MUST set fields in struct virtio_crypto_mac_para.sess_para. +\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 The device MUST copy the results of MAC operations to the hash_result[] if HASH operations success. +\item The device MUST set \field{status} in struct virtio_crypto_inhdr to one of the values of enum VIRITO_CRYPTO_STATUS. +\end{itemize*} + +\subsubsection{Symmetric algorithms Operation}\label{sec:Device Types / Crypto Device / Device Operation / Symmetric algorithms Operation} + +The packet of plain CIPHER service is as follows: + +\begin{lstlisting} +struct virtio_crypto_cipher_para { + struct { + /* See VIRTIO_CRYPTO_CIPHER* above */ + le32 algo; + /* length of key */ + le32 keylen; + + /* See VIRTIO_CRYPTO_OP_* above */ + le32 op; + } sess_para; + + /* + * 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; +}; + +struct virtio_crypto_cipher_data_req { + /* Device-readable part */ + struct virtio_crypto_cipher_para para; + /* The cipher key */ + u8 cipher_key[keylen]; + /* + * 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-writable part */ + /* Destination data */ + u8 dst_data[dst_data_len]; + struct virtio_crypto_inhdr inhdr; +}; +\end{lstlisting} + +The packet of algorithm chaining is as follows: + +\begin{lstlisting} +struct virtio_crypto_alg_chain_data_para { + struct { + /* See VIRTIO_CRYPTO_SYM_ALG_CHAIN_ORDER_* above */ + le32 alg_chain_order; + /* length of the additional authenticated data in bytes */ + le32 aad_len; + + struct { + /* See VIRTIO_CRYPTO_CIPHER* above */ + le32 algo; + /* length of key */ + le32 keylen; + /* See VIRTIO_CRYPTO_OP_* above */ + le32 op; + } cipher; + + struct { + /* See VIRTIO_CRYPTO_HASH_* or VIRTIO_CRYPTO_MAC_* above */ + le32 algo; + /* length of authenticated key */ + le32 auth_key_len; + /* See VIRTIO_CRYPTO_SYM_HASH_MODE_* above */ + le32 hash_mode; + } hash; + } sess_para; + + le32 iv_len; + /* Length of source data */ + le32 src_data_len; + /* Length of destination data */ + le32 dst_data_len; + /* Starting point for cipher processing in source data */ + le32 cipher_start_src_offset; + /* Length of the source data that the cipher will be computed on */ + le32 len_to_cipher; + /* Starting point for hash processing in source data */ + le32 hash_start_src_offset; + /* Length of the source data that the hash will be computed on */ + le32 len_to_hash; + /* Length of the additional auth data */ + le32 aad_len; + /* Length of the hash result */ + le32 hash_result_len; + le32 reserved; +}; + +struct virtio_crypto_alg_chain_data_req { + /* Device-readable part */ + struct virtio_crypto_alg_chain_data_para para; + /* The cipher key */ + u8 cipher_key[keylen]; + /* The auth key */ + u8 auth_key[auth_key_len]; + /* Initialization Vector or Counter data */ + u8 iv[iv_len]; + /* Source data */ + u8 src_data[src_data_len]; + /* Additional authenticated data if exists */ + u8 aad[aad_len]; + + /* Device-writable part */ + /* Destination data */ + u8 dst_data[dst_data_len]; + /* Hash result data */ + u8 hash_result[hash_result_len]; + struct virtio_crypto_inhdr inhdr; +}; +\end{lstlisting} + +The packet of symmetric algorithm is as follows: + +\begin{lstlisting} +struct virtio_crypto_sym_data_req { + union { + struct virtio_crypto_cipher_data_req cipher; + struct virtio_crypto_alg_chain_data_req chain; + } u; + + /* Device-readable part */ + + /* See above VIRTIO_CRYPTO_SYM_OP_* */ + le32 op_type; + le32 padding; +}; +\end{lstlisting} + +Each data request uses virtio_crypto_sym_data_req structure to store information +used to run the CIPHER operations. + +The information includes the cipher parameters stored by \field{para}, output data and input data. +In the first virtio_crypto_cipher_para structure, \field{iv_len} specifies the length of the initialization vector or counter, +\field{src_data_len} specifies the length of the source data, and \field{dst_data_len} specifies the +length of the destination data. +For plain CIPHER operations, the output data here includes the IV/Counter data and source data, and the input data includes the destination data used to save the results of the CIPHER operations. + +For algorithms chain, the output data here includes the IV/Counter data, source data and additional authenticated data if exists. +The input data includes both destination data and hash result data used to store the results of the HASH/MAC operations. +\field{inhdr} stores status of executing the crypto operations. + +\drivernormative{\paragraph}{Symmetric algorithms Operation}{Device Types / Crypto Device / Device Operation / Symmetric algorithms Operation} + +\begin{itemize*} +\item If the VIRTIO_CRYPTO_F_CIPHER_SESSION_MODE feature bit is negotiated and the driver uses the session mode, then the driver MUST set the \field{session_id} in struct virtio_crypto_op_header + to a valid value which assigned by the device when a session is created and MUST set \field{flag} field to VIRTIO_CRYPTO_FLAG_SESSION_MODE. +\item If the VIRTIO_CRYPTO_F_CIPHER_SESSION_MODE feature bit is not negotiated or the driver doesn't use the session mode, then the driver MUST set \field{flag} field in struct virtio_crypto_op_header + to VIRTIO_CRYPTO_FLAG_SESSION_NONE_MODE and MUST set fields in struct virtio_crypto_cipher_para.sess_para or struct virtio_crypto_alg_chain_data_para.sess_para. +\item The driver MUST set \field{opcode} in struct virtio_crypto_op_header to VIRTIO_CRYPTO_CIPHER_ENCRYPT or VIRTIO_CRYPTO_CIPHER_DECRYPT. +\item The driver MUST specify the fields of struct virtio_crypto_cipher_data_req in struct virtio_crypto_sym_data_req if the packet is based on VIRTIO_CRYPTO_SYM_OP_CIPHER. +\item The driver MUST specify the fields of both struct virtio_crypto_cipher_data_req and struct virtio_crypto_mac_data_req in struct virtio_crypto_sym_data_req if the packet + is of the VIRTIO_CRYPTO_SYM_OP_ALGORITHM_CHAINING type and in the VIRTIO_CRYPTO_SYM_HASH_MODE_AUTH mode. +\end{itemize*} + +\devicenormative{\paragraph}{Symmetric algorithms Operation}{Device Types / Crypto Device / Device Operation / Symmetric algorithms Operation} + +\begin{itemize*} +\item 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 parse the virtio_crypto_sym_data_req based on the \field{opcode} in general header. +\item The device SHOULD only parse fields of struct virtio_crypto_cipher_data_req in struct virtio_crypto_sym_data_req if the packet is VIRTIO_CRYPTO_SYM_OP_CIPHER type. +\item The device MUST parse fields of both struct virtio_crypto_cipher_data_req and struct virtio_crypto_mac_data_req in struct virtio_crypto_sym_data_req if the packet + is of the VIRTIO_CRYPTO_SYM_OP_ALGORITHM_CHAINING operation type and in the VIRTIO_CRYPTO_SYM_HASH_MODE_AUTH mode. +\item The device MUST copy the result of cryptographic operation to the dst_data[] in both plain CIPHER mode and algorithms chain mode. +\item The device MUST check the \field{para}.\field{add_len} is bigger than 0 before parse the additional authenticated data in plain algorithms chain mode. +\item The device MUST copy the result of HASH/MAC operation to the hash_result[] is of the VIRTIO_CRYPTO_SYM_OP_ALGORITHM_CHAINING type. +\item The device MUST set the \field{status} field in struct virtio_crypto_inhdr to one of the values of enum VIRITO_CRYPTO_STATUS. +\end{itemize*} + +\paragraph{Steps of Operation}\label{sec:Device Types / Crypto Device / Device Operation / Symmetric algorithms Operation / Steps of Operation} + +\subparagraph{Step1: Create session}\label{sec:Device Types / Crypto Device / Device Operation / Symmetric algorithms Operation / Steps of Operation / Step1: Create session if using session mode} + +\begin{enumerate} +\item The driver specifies information in struct virtio_crypto_op_ctrl_req, including the algorithm name, key, keylen etc; +\item The driver adds the request of session creation into the controlq's Vring Descriptor Table; +\item The driver kicks the device; +\item The device receives the request from controlq; +\item The device parses information about the request, and determines the information concerning the backend crypto accelerator; +\item The device packs information based on the APIs of the backend crypto accelerator; +\item The device invokes the session creation APIs of the backend crypto accelerator to create a session; +\item The device returns the session id to the driver. +\end{enumerate} + +\subparagraph{Step2: Execute cryptographic operation}\label{sec:Device Types / Crypto Device / Device Operation / Symmetric algorithms Operation / Steps of Operation / Step2: Execute cryptographic operation} + +\begin{enumerate} +\item The driver specifies information in struct virtio_crypto_op_data_req, including struct virtio_crypto_op_header and struct virtio_crypto_sym_data_req, see \ref{sec:Device Types / Crypto Device / Device + Operation / Symmetric algorithms Operation}; +\item The driver adds the request for cryptographic operation into the dataq's Vring Descriptor Table; +\item The driver kicks the device (Or the device actively polls the dataq's Vring Descriptor Table); +\item The device receives the request from dataq; +\item The device parses information about the request, and determines the identification information for the backend crypto accelerator. For example, converting guest physical addresses to host physical addresses; +\item The device packs identification information based on the API of the backend crypto accelerator; +\item The device invokes the cryptographic APIs of the backend crypto accelerator; +\item The backend crypto accelerator executes the cryptographic operation implicitly; +\item The device receives the cryptographic results from the backend crypto accelerator (synchronous or asynchronous); +\item The device sets the \field{status} in struct virtio_crypto_inhdr; +\item The device updates and flushes the Used Ring to return the cryptographic results to the driver; +\item The device notifies the driver (Or the driver actively polls the dataq's Used Ring); +\item The driver saves the cryptographic results. +\end{enumerate} + +\begin{note} +\begin{itemize*} +\item For better performance, the device should by preference use vhost scheme (user space or kernel space) + as the backend crypto accelerator in the real production environment. +\end{itemize*} +\end{note} + +\subsubsection{AEAD Service Operation}\label{sec:Device Types / Crypto Device / Device Operation / AEAD Service Operation} + +\begin{lstlisting} +struct virtio_crypto_aead_para { + struct { + /* See VIRTIO_CRYPTO_AEAD_* above */ + le32 algo; + /* length of key */ + le32 key_len; + /* encrypt or decrypt, See above VIRTIO_CRYPTO_OP_* */ + le32 op; + } sess_para; + + /* + * Byte Length of valid IV data. + * + * For GCM mode, this is either 12 (for 96-bit IVs) or 16, in which + * case iv points to J0. + * For CCM mode, this is the length of the nonce, which can be in the + * range 7 to 13 inclusive. + */ + le32 iv_len; + /* Authentication tag length */ + le32 tag_len; + /* length of additional auth data */ + le32 aad_len; + /* length of source data */ + le32 src_data_len; + /* length of dst data, this should be at least src_data_len + tag_len */ + le32 dst_data_len; +}; + +struct virtio_crypto_aead_data_req { + /* Device-readable part */ + struct virtio_crypto_aead_para para; + /* The cipher key */ + u8 key[key_len]; + /* + * Initialization Vector data. + * + * For GCM mode, this is either the IV (if the length is 96 bits) or J0 + * (for other sizes), where J0 is as defined by NIST SP800-38D. + * Regardless of the IV length, a full 16 bytes needs to be allocated. + * For CCM mode, the first byte is reserved, and the nonce should be + * written starting at &iv[1] (to allow space for the implementation + * to write in the flags in the first byte). Note that a full 16 bytes + * should be allocated, even though the iv_len field will have + * a value less than this. + * + * The IV will be updated after every partial cryptographic operation. + */ + u8 iv[iv_len]; + /* Source data */ + u8 src_data[src_data_len]; + /* Additional authenticated data if exists */ + u8 aad[aad_len]; + + /* Device-writable part */ + /* Pointer to output data */ + u8 dst_data[dst_data_len]; + + struct virtio_crypto_inhdr inhdr; +}; +\end{lstlisting} + +Each data request uses virtio_crypto_aead_data_req structure to store information +used to run the AEAD operations. + +The information includes the hash parameters stored by \field{para}, output data and input data. +In the first virtio_crypto_aead_para structure, \field{iv_len} specifies the length of the initialization vector. \field{tag_len} specifies the length of the authentication tag; +\field{aad_len} specifies the length of additional authentication data, \field{src_data_len} specifies the +length of the source data; \field{dst_data_len} specifies the length of the destination data, which is at least \field{src_data_len} + \field{tag_len}. + +The output data here includes the IV/Counter data, source data and additional authenticated data if exists. +The input data includes both destination data used to save the results of the AEAD operations. +\field{inhdr} stores status of executing the AEAD operations. + +\drivernormative{\paragraph}{AEAD Service Operation}{Device Types / Crypto Device / Device Operation / AEAD Service Operation} + +\begin{itemize*} +\item If the VIRTIO_CRYPTO_F_AEAD_SESSION_MODE feature bit is negotiated and the driver uses the session mode, then the driver MUST set the \field{session_id} in struct virtio_crypto_op_header + to a valid value which assigned by the device when a session is created and MUST set \field{flag} field to VIRTIO_CRYPTO_FLAG_SESSION_MODE. +\item If the VIRTIO_CRYPTO_F_AEAD_SESSION_MODE feature bit is not negotiated or the driver doesn't use the session mode, then the driver MUST set \field{flag} field in struct virtio_crypto_op_header + to VIRTIO_CRYPTO_FLAG_SESSION_NONE_MODE and MUST set fields in struct virtio_crypto_aead_para.sess_para. +\item The driver MUST set \field{opcode} in struct virtio_crypto_op_header to VIRTIO_CRYPTO_AEAD_ENCRYPT or VIRTIO_CRYPTO_AEAD_DECRYPT. +\end{itemize*} + +\devicenormative{\paragraph}{AEAD Service Operation}{Device Types / Crypto Device / Device Operation / AEAD Service Operation} + +\begin{itemize*} +\item The device MUST parse the virtio_crypto_aead_data_req based on the \field{opcode} in general header. +\item The device MUST copy the result of cryptographic operation to the dst_data[]. +\item The device MUST copy the authentication tag to the dst_data[] offset the cipher result. +\item The device MUST set the \field{status} field in struct virtio_crypto_inhdr to one of the values of enum VIRITO_CRYPTO_STATUS. +\item When the \field{opcode} is VIRTIO_CRYPTO_AEAD_DECRYPT, the device MUST verify and return the verification result to the driver, and if the verification result is incorrect, VIRTIO_CRYPTO_BADMSG (bad message) MUST be returned to the driver. +\end{itemize*} \ No newline at end of file