Hardware-accelerated CRC32, SHA1 and SHA256 (cryptographic) hashing for Teensy 4. More...

#include <Arduino.h>
#include "utils/dcp.h"

Include dependency graph for dcp.cpp:

Classes
struct	utils::_dcp_hash_ctx_t

union	utils::_dcp_hash_block

struct	utils::_dcp_handle

struct	utils::_dcp_hash_ctx_internal

struct	utils::_dcp_work_packet

struct	utils::DCP_Type
	DCP - Register Layout Typedef. More...

Namespaces
namespace	utils

Macros
#define	__IO volatile

#define	__I volatile

#define	DCP_CH0SEMA_VALUE_MASK (0xFF0000U)

#define	DCP_CH0STAT_ERROR_CODE_MASK (0xFF0000U)

#define	DCP_HASH_BLOCK_SIZE 128

#define	DCP_STAT_OTP_KEY_READY_MASK (0x10000000U)

#define	DCP_KEY_INDEX_MASK (0x30U)

#define	DCP_KEY_INDEX_SHIFT (4U)

#define	DCP_KEY_INDEX(x)

#define	DCP ((DCP_Type *)0x402FC000)

Typedefs
typedef enum utils::_dcp_ch_enable	utils::_dcp_ch_enable_t

typedef enum utils::_dcp_channel	utils::dcp_channel_t

typedef enum utils::_dcp_key_slot	utils::dcp_key_slot_t

typedef enum utils::_dcp_swap	utils::dcp_swap_t

typedef enum utils::_dcp_hash_algo_t	utils::dcp_hash_algo_t

typedef struct utils::_dcp_hash_ctx_t	utils::dcp_hash_ctx_t

typedef union utils::_dcp_hash_block	utils::dcp_hash_block_t

typedef enum utils::_dcp_hash_algo_state	utils::dcp_hash_algo_state_t

typedef struct utils::_dcp_handle	utils::dcp_handle_t

typedef struct utils::_dcp_hash_ctx_internal	utils::dcp_hash_ctx_internal_t

typedef struct utils::_dcp_work_packet	utils::dcp_work_packet_t

Enumerations
enum	utils::_generic_status { utils::kStatus_Success = 0 , utils::kStatus_Fail = 1 , utils::kStatus_ReadOnly = 2 , utils::kStatus_OutOfRange = 3 , utils::kStatus_InvalidArgument = 4 , utils::kStatus_Timeout = 5 , utils::kStatus_DCP_Again = 6 }

enum	utils::_dcp_ch_enable { utils::kDCP_chDisable = 0U , utils::kDCP_ch0Enable = 1U , utils::kDCP_ch1Enable = 2U , utils::kDCP_ch2Enable = 4U , utils::kDCP_ch3Enable = 8U , utils::kDCP_chEnableAll = 15U }

enum	utils::_dcp_channel { utils::kDCP_Channel0 = (1u << 16) , utils::kDCP_Channel1 = (1u << 17) , utils::kDCP_Channel2 = (1u << 18) , utils::kDCP_Channel3 = (1u << 19) }

enum	utils::_dcp_key_slot { utils::kDCP_KeySlot0 = 0U , utils::kDCP_KeySlot1 = 1U , utils::kDCP_KeySlot2 = 2U , utils::kDCP_KeySlot3 = 3U , utils::kDCP_OtpKey = 4U , utils::kDCP_OtpUniqueKey = 5U , utils::kDCP_PayloadKey = 6U }

enum	utils::_dcp_swap { utils::kDCP_NoSwap = 0x0U , utils::kDCP_KeyByteSwap = 0x40000U , utils::kDCP_KeyWordSwap = 0x80000U , utils::kDCP_InputByteSwap = 0x100000U , utils::kDCP_InputWordSwap = 0x200000U , utils::kDCP_OutputByteSwap = 0x400000U , utils::kDCP_OutputWordSwap = 0x800000U }

enum	utils::_dcp_hash_algo_t { utils::kDCP_Sha1 , utils::kDCP_Sha256 , utils::kDCP_Crc32 }

enum	utils::_dcp_hash_digest_len { utils::kDCP_OutLenSha1 = 20u , utils::kDCP_OutLenSha256 = 32u , utils::kDCP_OutLenCrc32 = 4u }

enum	utils::_dcp_work_packet_bit_definitions { utils::kDCP_CONTROL0_DECR_SEMAPHOR = 1u << 1 , utils::kDCP_CONTROL0_ENABLE_HASH = 1u << 6 , utils::kDCP_CONTROL0_HASH_INIT = 1u << 12 , utils::kDCP_CONTROL0_HASH_TERM = 1u << 13 , utils::kDCP_CONTROL1_HASH_SELECT_SHA256 = 2u << 16 , utils::kDCP_CONTROL1_HASH_SELECT_SHA1 = 0u << 16 , utils::kDCP_CONTROL1_HASH_SELECT_CRC32 = 1u << 16 }

enum	utils::_dcp_hash_algo_state { utils::kDCP_StateHashInit = 1u , utils::kDCP_StateHashUpdate }

Functions
static FLASHMEM void	utils::dcp_reverse_and_copy (uint8_t src, uint8_t dest, size_t src_len)

static FLASHMEM uint32_t	utils::dcp_get_channel_status (dcp_channel_t channel)

static FLASHMEM void	utils::dcp_clear_status ()

static FLASHMEM void	utils::dcp_clear_channel_status (uint32_t mask)

uint32_t	utils::DCP_WaitForChannelComplete (dcp_handle_t *handle)

static FLASHMEM uint32_t	utils::dcp_schedule_work (dcp_handle_t handle, dcp_work_packet_t dcpPacket)

static FLASHMEM uint32_t	utils::dcp_hash_update_non_blocking (dcp_hash_ctx_internal_t ctxInternal, dcp_work_packet_t dcpPacket, const uint8_t *msg, size_t size)

void	utils::dcp_hash_update (dcp_hash_ctx_internal_t ctxInternal, const uint8_t msg, size_t size)

FLASHMEM void	utils::dcp_hash_process_message_data (dcp_hash_ctx_internal_t ctxInternal, const uint8_t message, size_t messageSize)

FLASHMEM void	utils::DCP_HASH_Init (dcp_handle_t handle, dcp_hash_ctx_t ctx, dcp_hash_algo_t algo)

FLASHMEM void	utils::DCP_HASH_Update (dcp_hash_ctx_t ctx, const uint8_t input, size_t inputSize)

FLASHMEM void	utils::DCP_HASH_Finish (dcp_hash_ctx_t ctx, uint8_t output)

FLASHMEM void	utils::dcp_init ()

FLASHMEM void	utils::prhash (unsigned char *h, int n)

FLASHMEM void	utils::demo_sha256 ()

FLASHMEM void	utils::demo_crc32 ()

FLASHMEM void	utils::hash (const uint8_t msg, size_t msg_len, uint8_t out_hash, dcp_hash_algo_t algo)

FLASHMEM void	utils::hash_sha256 (const uint8_t msg, size_t msg_len, uint8_t out_hash)
	Computes the SHA256 sum of an arbitrary message (large memory segment).

FLASHMEM void	utils::hash_sha1 (const uint8_t msg, size_t msg_len, uint8_t out_hash)

Detailed Description

Hardware-accelerated CRC32, SHA1 and SHA256 (cryptographic) hashing for Teensy 4.

DCP stands for Data Co-Processor and provides hardware acceleration for cryptographic algorithms. Used for creating checksums of data. Performance is like 70MByte/sec with input data coming from flash, so it is pretty neat.

Finding the correct library to do the job costed me some trial-and-error:

First I tried out the CryptoAccel.h which is part of framework-arduinoteensy and available at https://github.com/PaulStoffregen/CryptoAccel. There is hardly any documentation. It can create CRC-32 variants in POSIX and ADCCP/PKZIP/Ethernet/802.3, however I could not reproduce a single of these checksums. CRC-32 is to ill-defined. Also considered https://www.etlcpp.com/hash.html but doesn't change CRC-32s nature.
Then I tried FastCRC which is also part of framework-arduinoteensy. It is written in assembly and silently creates wrong MD5sums for Teensy4 and also the md5sums. cf. https://forum.pjrc.com/index.php?threads/cryptoaccel-library-use-with-t4-1-for-encryption-decryption.71091/post-312784
Then I tried https://github.com/okdshin/PicoSHA2 which however just crashes on the Teensy. I guess this is because of the intensive heap usage of the std::vector buffers.
Then I tried this dcp header which I found at https://github.com/manitou48/teensy4/blob/master/dcptst.ino According to https://forum.pjrc.com/threads/54711-Teensy-4-0-First-Beta-Test?p=197722&viewfull=1#post197722 The code basically stems straight from the NXP SDK. This is the first code which produced a correct checksum/hash for me.