caam-blob.h

  1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * Copyright (C) 2020 Pengutronix, Ahmad Fatoum <kernel@pengutronix.de>
  4 * Copyright 2024-2025 NXP
  5 */
  6
  7#ifndef __CAAM_BLOB_GEN
  8#define __CAAM_BLOB_GEN
  9
 10#include <linux/types.h>
 11#include <linux/errno.h>
 12
 13#define CAAM_BLOB_KEYMOD_LENGTH		16
 14#define CAAM_BLOB_OVERHEAD		(32 + 16)
 15#define CAAM_BLOB_MAX_LEN		4096
 16#define CAAM_ENC_ALGO_CCM		0x1
 17#define CAAM_ENC_ALGO_ECB		0x2
 18#define CAAM_NONCE_SIZE			6
 19#define CAAM_ICV_SIZE			6
 20#define CAAM_CCM_OVERHEAD		(CAAM_NONCE_SIZE + CAAM_ICV_SIZE)
 21
 22struct caam_blob_priv;
 23
 24/**
 25 * struct caam_pkey_info - information for CAAM protected key
 26 * @is_pkey:		flag to identify, if the key is protected.
 27 * @key_enc_algo:	identifies the algorithm, ccm or ecb
 28 * @plain_key_sz:	size of plain key.
 29 * @key_buf:		contains key data
 30 */
 31struct caam_pkey_info {
 32	u8  is_pkey;
 33	u8  key_enc_algo;
 34	u16 plain_key_sz;
 35	u8 key_buf[];
 36} __packed;
 37
 38/* sizeof struct caam_pkey_info */
 39#define CAAM_PKEY_HEADER		4
 40
 41/**
 42 * struct caam_blob_info - information for CAAM blobbing
 43 * @pkey_info:	 pointer to keep protected key information
 44 * @input:       pointer to input buffer (must be DMAable)
 45 * @input_len:   length of @input buffer in bytes.
 46 * @output:      pointer to output buffer (must be DMAable)
 47 * @output_len:  length of @output buffer in bytes.
 48 * @key_mod:     key modifier
 49 * @key_mod_len: length of @key_mod in bytes.
 50 *	         May not exceed %CAAM_BLOB_KEYMOD_LENGTH
 51 */
 52struct caam_blob_info {
 53	struct caam_pkey_info pkey_info;
 54
 55	void *input;
 56	size_t input_len;
 57
 58	void *output;
 59	size_t output_len;
 60
 61	const void *key_mod;
 62	size_t key_mod_len;
 63};
 64
 65/**
 66 * caam_blob_gen_init - initialize blob generation
 67 * Return: pointer to new &struct caam_blob_priv instance on success
 68 * and ``ERR_PTR(-ENODEV)`` if CAAM has no hardware blobbing support
 69 * or no job ring could be allocated.
 70 */
 71struct caam_blob_priv *caam_blob_gen_init(void);
 72
 73/**
 74 * caam_blob_gen_exit - free blob generation resources
 75 * @priv: instance returned by caam_blob_gen_init()
 76 */
 77void caam_blob_gen_exit(struct caam_blob_priv *priv);
 78
 79/**
 80 * caam_process_blob - encapsulate or decapsulate blob
 81 * @priv:   instance returned by caam_blob_gen_init()
 82 * @info:   pointer to blobbing info describing key, blob and
 83 *          key modifier buffers.
 84 * @encap:  true for encapsulation, false for decapsulation
 85 *
 86 * Return: %0 and sets ``info->output_len`` on success and a negative
 87 * error code otherwise.
 88 */
 89int caam_process_blob(struct caam_blob_priv *priv,
 90		      struct caam_blob_info *info, bool encap);
 91
 92/**
 93 * caam_encap_blob - encapsulate blob
 94 * @priv:   instance returned by caam_blob_gen_init()
 95 * @info:   pointer to blobbing info describing input key,
 96 *          output blob and key modifier buffers.
 97 *
 98 * Return: %0 and sets ``info->output_len`` on success and
 99 * a negative error code otherwise.
100 */
101static inline int caam_encap_blob(struct caam_blob_priv *priv,
102				  struct caam_blob_info *info)
103{
104	if (info->output_len < info->input_len + CAAM_BLOB_OVERHEAD)
105		return -EINVAL;
106
107	return caam_process_blob(priv, info, true);
108}
109
110/**
111 * caam_decap_blob - decapsulate blob
112 * @priv:   instance returned by caam_blob_gen_init()
113 * @info:   pointer to blobbing info describing output key,
114 *          input blob and key modifier buffers.
115 *
116 * Return: %0 and sets ``info->output_len`` on success and
117 * a negative error code otherwise.
118 */
119static inline int caam_decap_blob(struct caam_blob_priv *priv,
120				  struct caam_blob_info *info)
121{
122	if (info->input_len < CAAM_BLOB_OVERHEAD ||
123	    info->output_len < info->input_len - CAAM_BLOB_OVERHEAD)
124		return -EINVAL;
125
126	return caam_process_blob(priv, info, false);
127}
128
129#endif