DES

This section introduces the DES driver APIs including terms and acronyms, supported features, software architecture, details on how to use this driver, DES function groups, enums, structures and functions. More...

Overview

This section introduces the DES driver APIs including terms and acronyms, supported features, software architecture, details on how to use this driver, DES function groups, enums, structures and functions.

Terms and acronyms

Terms	Details
DES	The Data Encryption Standard. For more information, please refer to introduction to the DES in Wikipedia .
CBC	The Cipher Block Chaining. For more information, please refer to introduction to the CBC in Wikipedia .
ECB	The Electronic Codebook. For more information, please refer to introduction to the ECB in Wikipedia .

Supported features

MediaTek MT7687 has two encryption modes in DES, CBC mode and ECB mode. In the CBC mode, each block of encryption mode is XOR'ed with the previous cipher block before being encrypted, Each cipher text block depends on all plain text blocks processed up to that point. In ECB mode, the message is divided into blocks, and each block is encrypted separately.

• Support CBC and ECB modes.
  Each mode has different hardware and software configuration.

How to use this driver

• Use DES in the CBC mode to encrypt and decrypt.
  
  • Step 1. Call hal_des_cbc_encrypt() to encrypt.
  • Step 2. Call hal_des_cbc_decrypt() to decrypt.
  • sample code:

    uint8_t des_cbc_iv[HAL_DES_CBC_IV_LENGTH] = {
        0x61, 0x33, 0x46, 0x68, 0x55, 0x38, 0x31, 0x43
    };
    uint8_t encrypted[32] = {0};
    uint8_t plain[30] = {
        0, 11, 22, 33, 44, 55, 66, 77, 88, 99, 0, 11, 22, 33, 44, 55, 66,
        77, 88, 99, 0, 11, 22, 33, 44, 55, 66, 77, 88, 99
    };
    hal_des_buffer_t plain_text = {
        .buffer = plain,
        .length = sizeof(plain)
    };
    hal_des_buffer_t key = {
        .buffer = hardware_id,
        .length = sizeof(hardware_id)
    };
    hal_des_buffer_t encrypted_text = {
        .buffer = encrypted,
        .length = sizeof(encrypted)
    };
    hal_des_cbc_encrypt(&encrypted_text, &plain_text, &key, des_cbc_iv);
    
    uint8_t decrypted_buffer[32] = {0};
    hal_aes_buffer_t decrypted_text = {
        .buffer = decrypted_buffer,
        .length = sizeof(decrypted_buffer)
    };
    hal_des_cbc_decrypt(&decrypted_text, &encrypted_text, &key, des_cbc_iv);

• Use DES in the ECB mode to encrypt and decrypt.
  
  • Step 1. call hal_des_ecb_encrypt() to encrypt.
  • Step 2. call hal_des_ecb_decrypt() to decrypt.
  • sample code:

    uint8_t hardware_id[8] = {
        0x4d, 0x54, 0x4b, 0x30, 0x30, 0x30, 0x30, 0x30
    };
    uint8_t plain[] = {
        0, 11, 22, 33, 44, 55, 66, 77, 88, 99, 0, 11, 22, 33, 44, 55,
        66, 77, 88, 99, 0, 11, 22, 33, 44, 55, 66, 77, 88, 99
    };
    hal_des_buffer_t plain_text = {
        .buffer = plain,
        .length = sizeof(plain)
    };
    hal_des_buffer_t key = {
        .buffer = hardware_id,
        .length = sizeof(hardware_id)
    };
    uint8_t encrypted_buffer[32] = {0};
    hal_des_buffer_t encrypted_text = {
        .buffer = encrypted_buffer,
        .length = sizeof(encrypted_buffer)
    };
    hal_des_ecb_encrypt(&encrypted_text, &plain_text, &key);
    
    uint8_t decrypted_buffer[32] = {0};
    hal_des_buffer_t decrypted_text = {
        .buffer = decrypted_buffer,
        .length = sizeof(decrypted_buffer)
    };
    hal_des_ecb_decrypt(&decrypted_text, &encrypted_text, &key);

Functions
hal_des_status_t	hal_des_cbc_encrypt (hal_des_buffer_t *encrypted_text, hal_des_buffer_t *plain_text, hal_des_buffer_t *key, uint8_t init_vector[(8)])
	DES encryption in the CBC mode. More...
hal_des_status_t	hal_des_cbc_decrypt (hal_des_buffer_t *plain_text, hal_des_buffer_t *encrypted_text, hal_des_buffer_t *key, uint8_t init_vector[(8)])
	DES decryption in the CBC mode. More...
hal_des_status_t	hal_des_ecb_encrypt (hal_des_buffer_t *encrypted_text, hal_des_buffer_t *plain_text, hal_des_buffer_t *key)
	DES encryption in the ECB mode. More...
hal_des_status_t	hal_des_ecb_decrypt (hal_des_buffer_t *plain_text, hal_des_buffer_t *encrypted_text, hal_des_buffer_t *key)
	DES decryption in the ECB mode. More...

Modules
	Define
	Enum
	Struct

Function Documentation

hal_des_status_t hal_des_cbc_decrypt	(	hal_des_buffer_t *	plain_text,
		hal_des_buffer_t *	encrypted_text,
		hal_des_buffer_t *	key,
		uint8_t	init_vector[(8)]
	)

DES decryption in the CBC mode.

Parameters

[out]	plain_text	is the target plain text.
[in]	encrypted_text	is the source encrypted text.
[in]	key	is the DES key for encryption.
[in]	init_vector	is the DES initialization vector for encryption.

Returns

HAL_DES_STATUS_OK, if the operation completed successfully.

Example

Sample code, please refer to How to use this driver

hal_des_status_t hal_des_cbc_encrypt	(	hal_des_buffer_t *	encrypted_text,
		hal_des_buffer_t *	plain_text,
		hal_des_buffer_t *	key,
		uint8_t	init_vector[(8)]
	)

DES encryption in the CBC mode.

Parameters

[out]	encrypted_text	is the target encrypted text.
[in]	plain_text	is the source plain text.
[in]	key	is the DES key for encryption.
[in]	init_vector	is the DES initialization vector for encryption.

Returns

HAL_DES_STATUS_OK, if the operation completed successfully.

Example

Sample code, please refer to How to use this driver

hal_des_status_t hal_des_ecb_decrypt	(	hal_des_buffer_t *	plain_text,
		hal_des_buffer_t *	encrypted_text,
		hal_des_buffer_t *	key
	)

DES decryption in the ECB mode.

Parameters

[out]	plain_text	is the target plain text.
[in]	encrypted_text	is the source encrypted text.
[in]	key	is the DES key for encryption.

Returns

HAL_DES_STATUS_OK, if the operation completed successfully.

Example

Sample code, please refer to How to use this driver

hal_des_status_t hal_des_ecb_encrypt	(	hal_des_buffer_t *	encrypted_text,
		hal_des_buffer_t *	plain_text,
		hal_des_buffer_t *	key
	)

DES encryption in the ECB mode.

Parameters

[out]	encrypted_text	is the target encrypted text.
[in]	plain_text	is the source plain text.
[in]	key	is the DES key for encryption.

Returns

HAL_DES_STATUS_OK, if the operation completed successfully.

Example

Sample code, please refer to How to use this driver