atecc608.hpp

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/*
 * SPDX-FileCopyrightText: 2025 M5Stack Technology CO LTD
 *
 * SPDX-License-Identifier: MIT
 */
#ifndef M5_UNIT_CRYPTO_ATECC608_HPP
#define M5_UNIT_CRYPTO_ATECC608_HPP
 
#include <cstdint>
 
namespace m5 {
namespace unit {
namespace atecc608 {
enum class Slot : uint8_t {
    PrimaryPrivateKey,            
    InternalSignPrivateKey,       
    SecondaryPrivateKey1,         
    SecondaryPrivateKey2,         
    SecondaryPrivateKey3,         
    MACAddress,                   
    IOProtectionKey,              
    GeneralData = 8,              
    AESKey,                       
    DeviceCompressedCertificate,  
    SignerPublicKey,              
    SignerCompressedCertificate,  
    // 7,13,14,15 are reserved
};
 
enum class Source : uint8_t {
    TempKey,             
    MsgDigestBuffer,     
    AlternateKeyBuffer,  
    ExternalBuffer,      
};
using Destination = Source;
 
constexpr uint8_t ZONE_CONFIG{0x00};
constexpr uint8_t ZONE_OTP{0x01};
constexpr uint8_t ZONE_DATA{0x02};
 
enum Error : uint8_t {
    CHECK_MAC_OR_VERIFY_ERROR  = 0x01,
    PARSE_ERROR                = 0x03,
    ECC_FAULT                  = 0x05,
    SELF_TEST_ERROR            = 0x07,
    HEALTH_TEST_ERROR          = 0x08,
    EXECUTION_ERROR            = 0x0F,
    AFTER_WAKE_PRIOR_ERROR     = 0X11,
    WATCH_DOG_ERROR            = 0xEE,
    CRC_OR_COMMUNICATION_ERROR = 0XFF,
};
 
constexpr uint32_t DELAY_READ{3};
constexpr uint32_t DELAY_WRITE{4};
constexpr uint32_t DELAY_INFO{2};
constexpr uint32_t DELAY_NONCE{16};
constexpr uint32_t DELAY_SELFTEST{200};
constexpr uint32_t DELAY_RANDOM{23};
constexpr uint32_t DELAY_COUNTER{20};
constexpr uint32_t DELAY_GENKEY{115};
constexpr uint32_t DELAY_SIGN{70};
constexpr uint32_t DELAY_SHA{9};
constexpr uint32_t DELAY_ECDH{58};
constexpr uint32_t DELAY_VERIFY{105};
 
constexpr uint8_t WORD_VALUE_RESET{0x00};
constexpr uint8_t WORD_ADRESS_VALUE_SLEEP{0x01};
constexpr uint8_t WORD_ADRESS_VALUE_IDLE{0x02};
constexpr uint8_t WORD_ADRESS_VALUE_COMMAND{0x03};
 
constexpr uint8_t OPCODE_READ{0x02};
// constexpr uint8_t OPCODE_WRITE{0x12};
constexpr uint8_t OPCODE_NONCE{0x16};
// constexpr uint8_t OPCODE_LOCK{0x17};
constexpr uint8_t OPCODE_RANDOM{0x1B};
constexpr uint8_t OPCODE_COUNTER{0x24};
constexpr uint8_t OPCODE_INFO{0x30};
constexpr uint8_t OPCODE_GENKEY{0x40};
constexpr uint8_t OPCODE_SIGN{0x41};
constexpr uint8_t OPCODE_ECDH{0x43};
constexpr uint8_t OPCODE_VERIFY{0x45};
constexpr uint8_t OPCODE_SHA{0x47};
constexpr uint8_t OPCODE_SELFTEST{0x77};
 
constexpr uint8_t INFO_MODE_REVISION{0x00};
constexpr uint8_t INFO_MODE_KEYVALID{0x01};
constexpr uint8_t INFO_MODE_DEVICE_STATE{0x02};
 
constexpr uint8_t NONCE_MODE_RANDOM_UPDATE_SEED{0x00};
constexpr uint8_t NONCE_MODE_RANDOM_NOT_UPDATE_SEED{0x01};
constexpr uint8_t NONCE_MODE_PASSTHROUGH{0x03};
constexpr uint8_t NONCE_MODE_INPUT_64{0x20};
 
constexpr uint8_t NONCE_MODE_TARGET_TEMPKEY{0x00};
constexpr uint8_t NONCE_MODE_TARGET_DIGEST{0x40};
constexpr uint8_t NONCE_MODE_TARGET_ALTKEY{0x80};
 
constexpr uint16_t NONCE_USE_TRNG{0x0000};
constexpr uint16_t NONCE_USE_TEMPKEY{0x8000};
 
constexpr uint8_t RANDOM_MODE_UPDATE_SEED{0x00};
constexpr uint8_t RANDOM_MODE_NOT_UPDATE_SEED{0x01};
 
constexpr uint8_t SHA_MODE_START{0x00};
constexpr uint8_t SHA_MODE_UPDATE{0x01};
constexpr uint8_t SHA_MODE_FINALIZE{0x02};
constexpr uint8_t SHA_MODE_OUTPUT_TEMPKEY{0x00};
constexpr uint8_t SHA_MODE_OUTPUT_DIGEST{0x40};
constexpr uint8_t SHA_MODE_OUTPUT_BUFFER{0xC0};
 
// constexpr uint8_t ECDH_MODE_SLOT{0x04};
constexpr uint8_t ECDH_MODE_SRC_SLOT{0x00};
constexpr uint8_t ECDH_MODE_SRC_TEMPKEY{0x01};
 
constexpr uint8_t ECDH_MODE_ENCRYPT{0x02};
 
constexpr uint8_t ECDH_MODE_OUTPUT_TEMPKEY{0x08};
constexpr uint8_t ECDH_MODE_OUTPUT_BUFFER{0x0C};
constexpr uint8_t ECDH_MODE_OUTPUT_SLOT{0x04};
 
constexpr uint8_t GENKEY_MODE_PUBLIC{0x00};
constexpr uint8_t GENKEY_MODE_PRIVATE{0x04};
constexpr uint8_t GENKEY_MODE_DIGEST{0x08};
constexpr uint8_t GENKEY_MODE_PUBLIC_DIGEST{0x10};
 
constexpr uint8_t SIGN_MODE_INTERNAL{0x00};
constexpr uint8_t SIGN_MODE_INCLUDE_SN{0x40};
constexpr uint8_t SIGN_MODE_EXTERNAL{0x80};
 
constexpr uint8_t SIGN_MODE_TEMPKEY{0x00};
constexpr uint8_t SIGN_MODE_DIGEST{0x20};
 
constexpr uint8_t VERIFY_MODE_STORED{0x00};
constexpr uint8_t VERIFY_MODE_EXTERNAL{0x02};
 
constexpr uint8_t VERIFY_MODE_TEMPKEY{0x00};
constexpr uint8_t VERIFY_MODE_DIGEST{0x20};
 
constexpr uint8_t VERIFY_MODE_MAC{0x80};
 
inline uint16_t offset_to_param2_for_config(const uint8_t offset)
{
    const uint8_t block = (offset >> 5) & 0x03;         // 0〜3
    const uint8_t index = ((offset & 31) >> 2) & 0x07;  // 0〜7
    return (block << 3) | index;
}
inline uint16_t slot_block_to_param2(const uint8_t slot, const uint8_t offset)
{
    const uint8_t block       = offset >> 5;         // 0〜2
    const uint8_t word_offset = (offset & 31) >> 2;  // 0〜7
    return (slot << 3) | (block << 8) | word_offset;
}
 
constexpr inline uint32_t encoded_base64_length(const uint32_t ilen)
{
    return ((ilen + 2) / 3) * 4;
}
 
bool convertToPEM(char* out, const uint32_t out_len, const uint8_t* der, uint32_t dlen,
                  const char* header = "CERTIFICATE", const char* footer = "CERTIFICATE");
 
extern const uint8_t template_for_device[];
extern const uint8_t template_for_signer[];
extern const uint32_t template_for_device_size;
extern const uint32_t template_for_signer_size;
 
/*1
  @class m5::unit::atecc608::CompCertAccessor
  @brief Compressed certificate accessor
 */
class CompCertAccessor {
public:
    struct DateTime {
        int tm_sec;   // 0 to 59
        int tm_min;   // 0 to 59
        int tm_hour;  // 0 to 23
        int tm_mday;  // 1 to 31
        int tm_mon;   // 0 to 11
        int tm_year;  // years since 1900
    };
 
    explicit CompCertAccessor(const uint8_t* data) : _data(data)
    {
        if (_data) {
            _issue_date  = get_issue_date();
            _expire_date = get_expire_date();
        }
    }
 
    inline uint8_t format_version() const
    {
        return _data[70] & 0x0F;
    }
    inline uint8_t template_id() const
    {
        return (_data[69] >> 4) & 0x0F;
    }
    inline uint8_t chain_id() const
    {
        return _data[69] & 0x0F;
    }
    inline uint8_t sn_source() const
    {
        return (_data[70] >> 4) & 0x0F;
    }
 
    inline const uint8_t* signer_id() const
    {
        return _data + 67;
    }
 
    inline const uint8_t* signature() const
    {
        return _data + 0;
    }
    inline const uint8_t* signature_r() const
    {
        return _data + 0;
    }
    inline const uint8_t* signature_s() const
    {
        return _data + 32;
    }
 
    inline DateTime issue_date() const
    {
        return _issue_date;
    }
    inline DateTime expire_date() const
    {
        return _expire_date;
    }
 
private:
    const uint8_t* _data{};
    DateTime _issue_date{}, _expire_date{};
 
    DateTime get_issue_date() const
    {
        DateTime dt{};
        uint8_t b64     = _data[64];
        uint8_t b65     = _data[65];
        uint8_t b66     = _data[66];
        uint8_t b71     = _data[71];
        uint8_t fmt_ver = format_version();
 
        if (fmt_ver == 1 || fmt_ver == 2) {
            dt.tm_year = ((((b71 & 0xC0) >> 1) | ((b64 >> 3) & 0x1F)) + 100);
        } else {
            dt.tm_year = ((b64 >> 3) + 100);
        }
        dt.tm_mon  = (((b64 & 0x07) << 1) | ((b65 & 0x80) >> 7)) - 1;
        dt.tm_mday = (b65 & 0x7C) >> 2;
        dt.tm_hour = ((b65 & 0x03) << 3) | ((b66 & 0xE0) >> 5);
        dt.tm_min  = 0;
        dt.tm_sec  = 0;
        return dt;
    }
 
    DateTime get_expire_date() const
    {
        DateTime dt     = issue_date();
        uint8_t b66     = _data[66];
        uint8_t b71     = _data[71];
        uint8_t fmt_ver = format_version();
        uint8_t expire_years{};
 
        if (fmt_ver == 1 || fmt_ver == 2) {
            expire_years = (b66 & 0x1F) | ((b71 & 0x30) << 1);
        } else {
            expire_years = b66 & 0x1F;
        }
 
        if (expire_years != 0) {
            dt.tm_year += expire_years;
        } else {
            // indefinite
            dt.tm_year = 9999 - 1900;
            dt.tm_mon  = 11;
            dt.tm_mday = 31;
            dt.tm_hour = 23;
            dt.tm_min  = 59;
            dt.tm_sec  = 59;
        }
        return dt;
    }
};
 
}  // namespace atecc608
}  // namespace unit
}  // namespace m5
#endif