Sha_algorithm_level_api

Overview

SHA Functional Operation
status_t	SHA_Init (SHA_Type *base, sha_ctx_t *ctx, sha_algo_t algo)
	Initialize HASH context. More...
status_t	SHA_Update (SHA_Type *base, sha_ctx_t *ctx, const uint8_t *message, size_t messageSize)
	Add data to current HASH. More...
status_t	SHA_Finish (SHA_Type *base, sha_ctx_t *ctx, uint8_t *output, size_t *outputSize)
	Finalize hashing. More...
void	SHA_SetCallback (SHA_Type *base, sha_ctx_t *ctx, sha_callback_t callback, void *userData)
	Initializes the SHA handle for background hashing. More...
status_t	SHA_UpdateNonBlocking (SHA_Type *base, sha_ctx_t *ctx, const uint8_t *input, size_t inputSize)
	Create running hash on given data. More...
void	SHA_ClkInit (SHA_Type *base)
	Start SHA clock. More...
void	SHA_ClkDeinit (SHA_Type *base)
	Stop SHA clock. More...

Function Documentation

status_t SHA_Init	(	SHA_Type *	base,
		sha_ctx_t *	ctx,
		sha_algo_t	algo
	)

This function initializes new hash context.

Parameters

	base	SHA peripheral base address
[out]	ctx	Output hash context
	algo	Underlaying algorithm to use for hash computation. Either SHA-1 or SHA-256.

Returns

Status of initialization

status_t SHA_Update	(	SHA_Type *	base,
		sha_ctx_t *	ctx,
		const uint8_t *	message,
		size_t	messageSize
	)

Add data to current HASH. This can be called repeatedly with an arbitrary amount of data to be hashed.

Parameters

	base	SHA peripheral base address
[in,out]	ctx	HASH context
	message	Input message
	messageSize	Size of input message in bytes

Returns

Status of the hash update operation

status_t SHA_Finish	(	SHA_Type *	base,
		sha_ctx_t *	ctx,
		uint8_t *	output,
		size_t *	outputSize
	)

Outputs the final hash and erases the context. SHA-1 or SHA-256 padding bits are automatically added by this function.

Parameters

	base	SHA peripheral base address
[in,out]	ctx	HASH context
[out]	output	Output hash data
[in,out]	outputSize	On input, determines the size of bytes of the output array. On output, tells how many bytes have been written to output.

Returns

Status of the hash finish operation

void SHA_SetCallback	(	SHA_Type *	base,
		sha_ctx_t *	ctx,
		sha_callback_t	callback,
		void *	userData
	)

This function initializes the hash context for background hashing (Non-blocking) APIs. This is less typical interface to hash function, but can be used for parallel processing, when main CPU has something else to do. Example is digital signature RSASSA-PKCS1-V1_5-VERIFY((n,e),M,S) algorithm, where background hashing of M can be started, then CPU can compute S^e mod n (in parallel with background hashing) and once the digest becomes available, CPU can proceed to comparison of EM with EM'.

Parameters

	base	SHA peripheral base address.
[out]	ctx	Hash context.
	callback	Callback function.
	userData	User data (to be passed as an argument to callback function, once callback is invoked from isr).

status_t SHA_UpdateNonBlocking	(	SHA_Type *	base,
		sha_ctx_t *	ctx,
		const uint8_t *	input,
		size_t	inputSize
	)

Configures the SHA to compute new running hash as AHB master and returns immediately. SHA AHB Master mode supports only aligned input address and can be called only once per continuous block of data. Every call to this function must be preceded with SHA_Init() and finished with _SHA_Finish(). Once callback function is invoked by SHA isr, it should set a flag for the main application to finalize the hashing (padding) and to read out the final digest by calling SHA_Finish().

Parameters

base	SHA peripheral base address
ctx	Specifies callback. Last incomplete 512-bit block of the input is copied into clear buffer for padding.
input	32-bit word aligned pointer to Input data.
inputSize	Size of input data in bytes (must be word aligned)

Returns

Status of the hash update operation.

void SHA_ClkInit

(

SHA_Type *

base

)

Start SHA clock

Parameters

base	SHA peripheral base address

void SHA_ClkDeinit

(

SHA_Type *

base

)

Stop SHA clock

Parameters

base	SHA peripheral base address