SHA-256 hash library

This module calculates SHA-256 (SHA-2, FIPS-180) hashes. More...

Data Structures
struct	sha256_context_t
	Current state of a hash operation. More...

Functions
ret_code_t	sha256_init (sha256_context_t *ctx)
	Function for initializing a sha256_context_t instance. More...
ret_code_t	sha256_update (sha256_context_t *ctx, const uint8_t *data, const size_t len)
	Function for calculating the hash of an array of uint8_t data. More...
ret_code_t	sha256_final (sha256_context_t *ctx, uint8_t *hash)
	Function for extracting the hash value from a hash instance. More...

Detailed Description

This module calculates SHA-256 (SHA-2, FIPS-180) hashes.

To use this module, first call sha256_init on a sha256_context_t instance. Then call sha256_update with the data to be hashed. This step can optionally be done with multiple calls to sha256_update, each with a section of the data (in the correct order). After all data has been passed to sha256_update, call sha256_final to finalize and extract the hash value.

This code is adapted from code by Brad Conte, retrieved from https://github.com/B-Con/crypto-algorithms.

Function Documentation

ret_code_t sha256_final	(	sha256_context_t *	ctx,
		uint8_t *	hash
	)

Function for extracting the hash value from a hash instance.

This function should be called after all data to be hashed has been passed to the hash instance (by one or more calls to sha256_update).

Do not call sha256_update again after sha256_final has been called.

Parameters

[in,out]	ctx	Hash instance.
[out]	hash	Array to hold the extracted hash value (assumed to be 32 bytes long).

Return values

NRF_SUCCESS	If the has value was successfully extracted.
NRF_ERROR_NULL	If a parameter was NULL.

ret_code_t sha256_init

(

sha256_context_t *

ctx

)

Function for initializing a sha256_context_t instance.

Parameters

[out]

ctx

Context instance to be initialized.

Return values

NRF_SUCCESS	If the instance was successfully initialized.
NRF_ERROR_NULL	If the parameter was NULL.

ret_code_t sha256_update	(	sha256_context_t *	ctx,
		const uint8_t *	data,
		const size_t	len
	)

Function for calculating the hash of an array of uint8_t data.

This function can be called multiple times in sequence. This is equivalent to calling the function once on a concatenation of the data from the different calls.

Parameters

[in,out]	ctx	Hash instance.
[in]	data	Data to be hashed.
[in]	len	Length of the data to be hashed.

Return values

NRF_SUCCESS	If the data was successfully hashed.
NRF_ERROR_NULL	If the ctx parameter was NULL or the data parameter was NULL, while the len parameter was not zero.