rpmb_protocol.h

/*
 * Copyright (C) 2018 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#pragma once

#include <stdint.h>

#include "rpmb.h" /* For struct rpmb_key */

#define MMC_READ_MULTIPLE_BLOCK 18
#define MMC_WRITE_MULTIPLE_BLOCK 25
#define MMC_RELIABLE_WRITE_FLAG (1 << 31)

#define MMC_RSP_PRESENT (1 << 0)
#define MMC_RSP_CRC (1 << 2)
#define MMC_RSP_OPCODE (1 << 4)
#define MMC_CMD_ADTC (1 << 5)
#define MMC_RSP_SPI_S1 (1 << 7)
#define MMC_RSP_R1 (MMC_RSP_PRESENT | MMC_RSP_CRC | MMC_RSP_OPCODE)
#define MMC_RSP_SPI_R1 (MMC_RSP_SPI_S1)

struct rpmb_nonce {
    uint8_t byte[16];
};

struct rpmb_u16 {
    uint8_t byte[2];
};

struct rpmb_u32 {
    uint8_t byte[4];
};

#define RPMB_PACKET_DATA_SIZE (256)
#define RPMB_WRITE_COUNTER_EXPIRED_VALUE (~0U)

struct rpmb_packet {
    uint8_t pad[196];
    struct rpmb_key key_mac;
    uint8_t data[RPMB_PACKET_DATA_SIZE];
    struct rpmb_nonce nonce;
    struct rpmb_u32 write_counter;
    struct rpmb_u16 address;
    struct rpmb_u16 block_count;
    struct rpmb_u16 result;
    struct rpmb_u16 req_resp;
};

enum rpmb_request {
    RPMB_REQ_PROGRAM_KEY = 0x0001,
    RPMB_REQ_GET_COUNTER = 0x0002,
    RPMB_REQ_DATA_WRITE = 0x0003,
    RPMB_REQ_DATA_READ = 0x0004,
    RPMB_REQ_RESULT_READ = 0x0005,
};

enum rpmb_response {
    RPMB_RESP_PROGRAM_KEY = 0x0100,
    RPMB_RESP_GET_COUNTER = 0x0200,
    RPMB_RESP_DATA_WRITE = 0x0300,
    RPMB_RESP_DATA_READ = 0x0400,
};

enum rpmb_result {
    RPMB_RES_OK = 0x0000,
    RPMB_RES_GENERAL_FAILURE = 0x0001,
    RPMB_RES_AUTH_FAILURE = 0x0002,
    RPMB_RES_COUNT_FAILURE = 0x0003,
    RPMB_RES_ADDR_FAILURE = 0x0004,
    RPMB_RES_WRITE_FAILURE = 0x0005,
    RPMB_RES_READ_FAILURE = 0x0006,
    RPMB_RES_NO_AUTH_KEY = 0x0007,

    RPMB_RES_WRITE_COUNTER_EXPIRED = 0x0080,
};

static inline struct rpmb_u16 rpmb_u16(uint16_t val) {
    struct rpmb_u16 ret = {{
            (uint8_t)(val >> 8),
            (uint8_t)(val >> 0),
    }};
    return ret;
}

static inline struct rpmb_u32 rpmb_u32(uint32_t val) {
    struct rpmb_u32 ret = {{
            (uint8_t)(val >> 24),
            (uint8_t)(val >> 16),
            (uint8_t)(val >> 8),
            (uint8_t)(val >> 0),
    }};
    return ret;
}

static inline uint16_t rpmb_get_u16(struct rpmb_u16 u16) {
    size_t i;
    uint16_t val;

    val = 0;
    for (i = 0; i < sizeof(u16.byte); i++)
        val = val << 8 | u16.byte[i];

    return val;
}

static inline uint32_t rpmb_get_u32(struct rpmb_u32 u32) {
    size_t i;
    uint32_t val;

    val = 0;
    for (i = 0; i < sizeof(u32.byte); i++)
        val = val << 8 | u32.byte[i];

    return val;
}