/* * Copyright (c) 2016 Intel Corporation. * * SPDX-License-Identifier: Apache-2.0 */ /** * @file * @brief Crypto Cipher structure definitions * * This file contains the Crypto Abstraction layer structures. * * [Experimental] Users should note that the Structures can change * as a part of ongoing development. */ #ifndef ZEPHYR_INCLUDE_CRYPTO_CIPHER_STRUCTS_H_ #define ZEPHYR_INCLUDE_CRYPTO_CIPHER_STRUCTS_H_ #include #include /** * @addtogroup crypto_cipher * @{ */ /** Cipher Algorithm */ enum cipher_algo { CRYPTO_CIPHER_ALGO_AES = 1, }; /** Cipher Operation */ enum cipher_op { CRYPTO_CIPHER_OP_DECRYPT = 0, CRYPTO_CIPHER_OP_ENCRYPT = 1, }; /** * Possible cipher mode options. * * More to be added as required. */ enum cipher_mode { CRYPTO_CIPHER_MODE_ECB = 1, CRYPTO_CIPHER_MODE_CBC = 2, CRYPTO_CIPHER_MODE_CTR = 3, CRYPTO_CIPHER_MODE_CCM = 4, CRYPTO_CIPHER_MODE_GCM = 5, }; /* Forward declarations */ struct cipher_aead_pkt; struct cipher_ctx; struct cipher_pkt; typedef int (*block_op_t)(struct cipher_ctx *ctx, struct cipher_pkt *pkt); /* Function signatures for encryption/ decryption using standard cipher modes * like CBC, CTR, CCM. */ typedef int (*cbc_op_t)(struct cipher_ctx *ctx, struct cipher_pkt *pkt, u8_t *iv); typedef int (*ctr_op_t)(struct cipher_ctx *ctx, struct cipher_pkt *pkt, u8_t *ctr); typedef int (*ccm_op_t)(struct cipher_ctx *ctx, struct cipher_aead_pkt *pkt, u8_t *nonce); typedef int (*gcm_op_t)(struct cipher_ctx *ctx, struct cipher_aead_pkt *pkt, u8_t *nonce); struct cipher_ops { enum cipher_mode cipher_mode; union { block_op_t block_crypt_hndlr; cbc_op_t cbc_crypt_hndlr; ctr_op_t ctr_crypt_hndlr; ccm_op_t ccm_crypt_hndlr; gcm_op_t gcm_crypt_hndlr; }; }; struct ccm_params { u16_t tag_len; u16_t nonce_len; }; struct ctr_params { /* CTR mode counter is a split counter composed of iv and counter * such that ivlen + ctr_len = keylen */ u32_t ctr_len; }; struct gcm_params { u16_t tag_len; u16_t nonce_len; }; /** * Structure encoding session parameters. * * Refer to comments for individual fields to know the contract * in terms of who fills what and when w.r.t begin_session() call. */ struct cipher_ctx { /** Place for driver to return function pointers to be invoked per * cipher operation. To be populated by crypto driver on return from * begin_session() based on the algo/mode chosen by the app. */ struct cipher_ops ops; /** To be populated by the app before calling begin_session() */ union { /* Cryptographic key to be used in this session */ u8_t *bit_stream; /* For cases where key is protected and is not * available to caller */ void *handle; } key; /** The device driver instance this crypto context relates to. Will be * populated by the begin_session() API. */ struct device *device; /** If the driver supports multiple simultaneously crypto sessions, this * will identify the specific driver state this crypto session relates * to. Since dynamic memory allocation is not possible, it is * suggested that at build time drivers allocate space for the * max simultaneous sessions they intend to support. To be populated * by the driver on return from begin_session(). */ void *drv_sessn_state; /** Place for the user app to put info relevant stuff for resuming when * completion callback happens for async ops. Totally managed by the * app. */ void *app_sessn_state; /** Cypher mode parameters, which remain constant for all ops * in a session. To be populated by the app before calling * begin_session(). */ union { struct ccm_params ccm_info; struct ctr_params ctr_info; struct gcm_params gcm_info; } mode_params; /** Cryptographic keylength in bytes. To be populated by the app * before calling begin_session() */ u16_t keylen; /** How certain fields are to be interpreted for this session. * (A bitmask of CAP_* below.) * To be populated by the app before calling begin_session(). * An app can obtain the capability flags supported by a hw/driver * by calling cipher_query_hwcaps(). */ u16_t flags; }; /* cipher_ctx.flags values. Not all drivers support all flags. * A user app can query the supported hw / driver * capabilities via provided API (cipher_query_hwcaps()), and choose a * supported config during the session setup. */ #define CAP_OPAQUE_KEY_HNDL BIT(0) #define CAP_RAW_KEY BIT(1) /* TBD to define */ #define CAP_KEY_LOADING_API BIT(2) /** Whether the output is placed in separate buffer or not */ #define CAP_INPLACE_OPS BIT(3) #define CAP_SEPARATE_IO_BUFS BIT(4) /** * These denotes if the output (completion of a cipher_xxx_op) is conveyed * by the op function returning, or it is conveyed by an async notification */ #define CAP_SYNC_OPS BIT(5) #define CAP_ASYNC_OPS BIT(6) /** Whether the hardware/driver supports autononce feature */ #define CAP_AUTONONCE BIT(7) /** Don't prefix IV to cipher blocks */ #define CAP_NO_IV_PREFIX BIT(8) /* More flags to be added as necessary */ /** * Structure encoding IO parameters of one cryptographic * operation like encrypt/decrypt. * * The fields which has not been explicitly called out has to * be filled up by the app before making the cipher_xxx_op() * call. */ struct cipher_pkt { /** Start address of input buffer */ u8_t *in_buf; /** Bytes to be operated upon */ int in_len; /** Start of the output buffer, to be allocated by * the application. Can be NULL for in-place ops. To be populated * with contents by the driver on return from op / async callback. */ u8_t *out_buf; /** Size of the out_buf area allocated by the application. Drivers * should not write past the size of output buffer. */ int out_buf_max; /** To be populated by driver on return from cipher_xxx_op() and * holds the size of the actual result. */ int out_len; /** Context this packet relates to. This can be useful to get the * session details, especially for async ops. Will be populated by the * cipher_xxx_op() API based on the ctx parameter. */ struct cipher_ctx *ctx; }; /** * Structure encoding IO parameters in AEAD (Authenticated Encryption * with Associated Data) scenario like in CCM. * * App has to furnish valid contents prior to making cipher_ccm_op() call. */ struct cipher_aead_pkt { /* IO buffers for encryption. This has to be supplied by the app. */ struct cipher_pkt *pkt; /** * Start address for Associated Data. This has to be supplied by app. */ u8_t *ad; /** Size of Associated Data. This has to be supplied by the app. */ u32_t ad_len; /** Start address for the auth hash. For an encryption op this will * be populated by the driver when it returns from cipher_ccm_op call. * For a decryption op this has to be supplied by the app. */ u8_t *tag; }; /* Prototype for the application function to be invoked by the crypto driver * on completion of an async request. The app may get the session context * via the pkt->ctx field. For CCM ops the encompassing AEAD packet may be * accessed via container_of(). The type of a packet can be determined via * pkt->ctx.ops.mode . */ typedef void (*crypto_completion_cb)(struct cipher_pkt *completed, int status); /** * @} */ #endif /* ZEPHYR_INCLUDE_CRYPTO_CIPHER_STRUCTS_H_ */