The generic message-digest wrapper. More...

Data Structures
struct	mbedtls_md_context_t
	The generic message-digest context. More...
Typedefs
typedef struct mbedtls_md_info_t	mbedtls_md_info_t
	Opaque struct defined in md_internal.h.
Enumerations
enum	mbedtls_md_type_t
	Enumeration of supported message digests. More...
Functions
const int *	mbedtls_md_list (void)
	This function returns the list of digests supported by the generic digest module.
const mbedtls_md_info_t *	mbedtls_md_info_from_string (const char *md_name)
	This function returns the message-digest information associated with the given digest name.
const mbedtls_md_info_t *	mbedtls_md_info_from_type (mbedtls_md_type_t md_type)
	This function returns the message-digest information associated with the given digest type.
void	mbedtls_md_init (mbedtls_md_context_t *ctx)
	This function initializes a message-digest context without binding it to a particular message-digest algorithm.
void	mbedtls_md_free (mbedtls_md_context_t *ctx)
	This function clears the internal structure of `ctx` and frees any embedded internal structure, but does not free `ctx` itself.
int	mbedtls_md_init_ctx (mbedtls_md_context_t ctx, const mbedtls_md_info_t md_info) MBEDTLS_DEPRECATED
	This function selects the message digest algorithm to use, and allocates internal structures.
int	mbedtls_md_setup (mbedtls_md_context_t ctx, const mbedtls_md_info_t md_info, int hmac)
	This function selects the message digest algorithm to use, and allocates internal structures.
int	mbedtls_md_clone (mbedtls_md_context_t dst, const mbedtls_md_context_t src)
	This function clones the state of an message-digest context.
unsigned char	mbedtls_md_get_size (const mbedtls_md_info_t *md_info)
	This function extracts the message-digest size from the message-digest information structure.
mbedtls_md_type_t	mbedtls_md_get_type (const mbedtls_md_info_t *md_info)
	This function extracts the message-digest type from the message-digest information structure.
const char *	mbedtls_md_get_name (const mbedtls_md_info_t *md_info)
	This function extracts the message-digest name from the message-digest information structure.
int	mbedtls_md_starts (mbedtls_md_context_t *ctx)
	This function starts a message-digest computation.
int	mbedtls_md_update (mbedtls_md_context_t ctx, const unsigned char input, size_t ilen)
	This function feeds an input buffer into an ongoing message-digest computation.
int	mbedtls_md_finish (mbedtls_md_context_t ctx, unsigned char output)
	This function finishes the digest operation, and writes the result to the output buffer.
int	mbedtls_md (const mbedtls_md_info_t md_info, const unsigned char input, size_t ilen, unsigned char *output)
	This function calculates the message-digest of a buffer, with respect to a configurable message-digest algorithm in a single call.
int	mbedtls_md_file (const mbedtls_md_info_t md_info, const char path, unsigned char *output)
	This function calculates the message-digest checksum result of the contents of the provided file.
int	mbedtls_md_hmac_starts (mbedtls_md_context_t ctx, const unsigned char key, size_t keylen)
	This function sets the HMAC key and prepares to authenticate a new message.
int	mbedtls_md_hmac_update (mbedtls_md_context_t ctx, const unsigned char input, size_t ilen)
	This function feeds an input buffer into an ongoing HMAC computation.
int	mbedtls_md_hmac_finish (mbedtls_md_context_t ctx, unsigned char output)
	This function finishes the HMAC operation, and writes the result to the output buffer.
int	mbedtls_md_hmac_reset (mbedtls_md_context_t *ctx)
	This function prepares to authenticate a new message with the same key as the previous HMAC operation.
int	mbedtls_md_hmac (const mbedtls_md_info_t md_info, const unsigned char key, size_t keylen, const unsigned char input, size_t ilen, unsigned char output)
	This function calculates the full generic HMAC on the input buffer with the provided key.

Detailed Description

The generic message-digest wrapper.

Author:: Adriaan de Jong <dejong@fox-it.com>

Definition in file md.h.

Typedef Documentation

typedef struct mbedtls_md_info_t mbedtls_md_info_t

Opaque struct defined in md_internal.h.

Definition at line 78 of file md.h.

Enumeration Type Documentation

enum mbedtls_md_type_t

Enumeration of supported message digests.

Warning:: MD2, MD4, MD5 and SHA-1 are considered weak message digests and their use constitutes a security risk. We recommend considering stronger message digests instead.

Definition at line 56 of file md.h.

Function Documentation

int mbedtls_md	(	const mbedtls_md_info_t *	md_info,
		const unsigned char *	input,
		size_t	ilen,
		unsigned char *	output
	)

This function calculates the message-digest of a buffer, with respect to a configurable message-digest algorithm in a single call.

The result is calculated as Output = message_digest(input buffer).

Parameters:

md_info	The information structure of the message-digest algorithm to use.
input	The buffer holding the data.
ilen	The length of the input data.
output	The generic message-digest checksum result.

Returns:: 0 on success, or MBEDTLS_ERR_MD_BAD_INPUT_DATA if parameter verification fails.

Definition at line 272 of file md.c.

int mbedtls_md_clone	(	mbedtls_md_context_t *	dst,
		const mbedtls_md_context_t *	src
	)

This function clones the state of an message-digest context.

Note:: You must call mbedtls_md_setup() on dst before calling this function.; The two contexts must have the same type, for example, both are SHA-256.

Warning:: This function clones the message-digest state, not the HMAC state.

Parameters:

dst	The destination context.
src	The context to be cloned.

Returns:: 0 on success, MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter failure.

Definition at line 203 of file md.c.

int mbedtls_md_file	(	const mbedtls_md_info_t *	md_info,
		const char *	path,
		unsigned char *	output
	)

This function calculates the message-digest checksum result of the contents of the provided file.

The result is calculated as Output = message_digest(file contents).

Parameters:

md_info	The information structure of the message-digest algorithm to use.
path	The input file name.
output	The generic message-digest checksum result.

Returns:: 0 on success, MBEDTLS_ERR_MD_FILE_IO_ERROR if file input failed, or MBEDTLS_ERR_MD_BAD_INPUT_DATA if md_info was NULL.

Definition at line 282 of file md.c.

int mbedtls_md_finish	(	mbedtls_md_context_t *	ctx,
		unsigned char *	output
	)

This function finishes the digest operation, and writes the result to the output buffer.

Call this function after a call to mbedtls_md_starts(), followed by any number of calls to mbedtls_md_update(). Afterwards, you may either clear the context with mbedtls_md_free(), or call mbedtls_md_starts() to reuse the context for another digest operation with the same algorithm.

Parameters:

ctx	The generic message-digest context.
output	The buffer for the generic message-digest checksum result.

Returns:: 0 on success, or MBEDTLS_ERR_MD_BAD_INPUT_DATA if parameter verification fails.

Definition at line 264 of file md.c.

void mbedtls_md_free ( mbedtls_md_context_t * ctx )

This function clears the internal structure of ctx and frees any embedded internal structure, but does not free ctx itself.

If you have called mbedtls_md_setup() on ctx, you must call mbedtls_md_free() when you are no longer using the context. Calling this function if you have previously called mbedtls_md_init() and nothing else is optional. You must not call this function if you have not called mbedtls_md_init().

Definition at line 186 of file md.c.

const char* mbedtls_md_get_name ( const mbedtls_md_info_t * md_info )

This function extracts the message-digest name from the message-digest information structure.

Parameters:

md_info The information structure of the message-digest algorithm to use.

Returns:: The name of the message digest.

Definition at line 470 of file md.c.

unsigned char mbedtls_md_get_size ( const mbedtls_md_info_t * md_info )

This function extracts the message-digest size from the message-digest information structure.

Parameters:

md_info The information structure of the message-digest algorithm to use.

Returns:: The size of the message-digest output in Bytes.

Definition at line 454 of file md.c.

mbedtls_md_type_t mbedtls_md_get_type ( const mbedtls_md_info_t * md_info )

This function extracts the message-digest type from the message-digest information structure.

Parameters:

md_info The information structure of the message-digest algorithm to use.

Returns:: The type of the message digest.

Definition at line 462 of file md.c.

int mbedtls_md_hmac	(	const mbedtls_md_info_t *	md_info,
		const unsigned char *	key,
		size_t	keylen,
		const unsigned char *	input,
		size_t	ilen,
		unsigned char *	output
	)

This function calculates the full generic HMAC on the input buffer with the provided key.

The function allocates the context, performs the calculation, and frees the context.

The HMAC result is calculated as output = generic HMAC(hmac key, input buffer).

Parameters:

md_info	The information structure of the message-digest algorithm to use.
key	The HMAC secret key.
keylen	The length of the HMAC secret key in Bytes.
input	The buffer holding the input data.
ilen	The length of the input data.
output	The generic HMAC result.

Returns:: 0 on success, or MBEDTLS_ERR_MD_BAD_INPUT_DATA if parameter verification fails.

Definition at line 417 of file md.c.

int mbedtls_md_hmac_finish	(	mbedtls_md_context_t *	ctx,
		unsigned char *	output
	)

This function finishes the HMAC operation, and writes the result to the output buffer.

Call this function after mbedtls_md_hmac_starts() and mbedtls_md_hmac_update() to get the HMAC value. Afterwards you may either call mbedtls_md_free() to clear the context, or call mbedtls_md_hmac_reset() to reuse the context with the same HMAC key.

Parameters:

ctx	The message digest context containing an embedded HMAC context.
output	The generic HMAC checksum result.

Returns:: 0 on success, or MBEDTLS_ERR_MD_BAD_INPUT_DATA if parameter verification fails.

Definition at line 377 of file md.c.

int mbedtls_md_hmac_reset ( mbedtls_md_context_t * ctx )

This function prepares to authenticate a new message with the same key as the previous HMAC operation.

You may call this function after mbedtls_md_hmac_finish(). Afterwards call mbedtls_md_hmac_update() to pass the new input.

Parameters:

ctx	The message digest context containing an embedded HMAC context.

Returns:: 0 on success, or MBEDTLS_ERR_MD_BAD_INPUT_DATA if parameter verification fails.

Definition at line 401 of file md.c.

int mbedtls_md_hmac_starts	(	mbedtls_md_context_t *	ctx,
		const unsigned char *	key,
		size_t	keylen
	)

This function sets the HMAC key and prepares to authenticate a new message.

Call this function after mbedtls_md_setup(), to use the MD context for an HMAC calculation, then call mbedtls_md_hmac_update() to provide the input data, and mbedtls_md_hmac_finish() to get the HMAC value.

Parameters:

ctx	The message digest context containing an embedded HMAC context.
key	The HMAC secret key.
keylen	The length of the HMAC key in Bytes.

Returns:: 0 on success, or MBEDTLS_ERR_MD_BAD_INPUT_DATA if parameter verification fails.

Definition at line 322 of file md.c.

int mbedtls_md_hmac_update	(	mbedtls_md_context_t *	ctx,
		const unsigned char *	input,
		size_t	ilen
	)

This function feeds an input buffer into an ongoing HMAC computation.

Call mbedtls_md_hmac_starts() or mbedtls_md_hmac_reset() before calling this function. You may call this function multiple times to pass the input piecewise. Afterwards, call mbedtls_md_hmac_finish().

Parameters:

ctx	The message digest context containing an embedded HMAC context.
input	The buffer holding the input data.
ilen	The length of the input data.

Returns:: 0 on success, or MBEDTLS_ERR_MD_BAD_INPUT_DATA if parameter verification fails.

Definition at line 369 of file md.c.

const mbedtls_md_info_t* mbedtls_md_info_from_string ( const char * md_name )

This function returns the message-digest information associated with the given digest name.

Parameters:

md_name The name of the digest to search for.

Returns:: The message-digest information associated with md_name, or NULL if not found.

Definition at line 99 of file md.c.

const mbedtls_md_info_t* mbedtls_md_info_from_type ( mbedtls_md_type_t md_type )

This function returns the message-digest information associated with the given digest type.

Parameters:

md_type The type of digest to search for.

Returns:: The message-digest information associated with md_type, or NULL if not found.

Definition at line 140 of file md.c.

void mbedtls_md_init ( mbedtls_md_context_t * ctx )

This function initializes a message-digest context without binding it to a particular message-digest algorithm.

This function should always be called first. It prepares the context for mbedtls_md_setup() for binding it to a message-digest algorithm.

Definition at line 181 of file md.c.

int mbedtls_md_init_ctx	(	mbedtls_md_context_t *	ctx,
		const mbedtls_md_info_t *	md_info
	)

This function selects the message digest algorithm to use, and allocates internal structures.

It should be called after mbedtls_md_init() or mbedtls_md_free(). Makes it necessary to call mbedtls_md_free() later.

Parameters:

ctx	The context to set up.
md_info	The information structure of the message-digest algorithm to use.

Returns:: 0 on success, MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter failure, MBEDTLS_ERR_MD_ALLOC_FAILED memory allocation failure.

Definition at line 219 of file md.c.

const int* mbedtls_md_list ( void )

This function returns the list of digests supported by the generic digest module.

Returns:: A statically allocated array of digests. Each element in the returned list is an integer belonging to the message-digest enumeration mbedtls_md_type_t. The last entry is 0.

Definition at line 94 of file md.c.

int mbedtls_md_setup	(	mbedtls_md_context_t *	ctx,
		const mbedtls_md_info_t *	md_info,
		int	hmac
	)

This function selects the message digest algorithm to use, and allocates internal structures.

It should be called after mbedtls_md_init() or mbedtls_md_free(). Makes it necessary to call mbedtls_md_free() later.

Parameters:

ctx	The context to set up.
md_info	The information structure of the message-digest algorithm to use.
hmac	0: HMAC is not used. Saves some memory. non-zero: HMAC is used with this context.

Returns:: 0 on success, MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter failure, or MBEDTLS_ERR_MD_ALLOC_FAILED on memory allocation failure.

Definition at line 225 of file md.c.

int mbedtls_md_starts ( mbedtls_md_context_t * ctx )

This function starts a message-digest computation.

You must call this function after setting up the context with mbedtls_md_setup(), and before passing data with mbedtls_md_update().

Parameters:

ctx	The generic message-digest context.

Returns:: 0 on success, MBEDTLS_ERR_MD_BAD_INPUT_DATA if parameter verification fails.

Definition at line 248 of file md.c.

int mbedtls_md_update	(	mbedtls_md_context_t *	ctx,
		const unsigned char *	input,
		size_t	ilen
	)

This function feeds an input buffer into an ongoing message-digest computation.

You must call mbedtls_md_starts() before calling this function. You may call this function multiple times. Afterwards, call mbedtls_md_finish().

Parameters:

ctx	The generic message-digest context.
input	The buffer holding the input data.
ilen	The length of the input data.

Returns:: 0 on success, MBEDTLS_ERR_MD_BAD_INPUT_DATA if parameter verification fails.

Definition at line 256 of file md.c.

Type:	Program
Mbed OS support:	Mbed OS
Created:	29 Mar 2018
Imports:	22
Forks:	0
Commits:	5
Dependents:	0
Dependencies:	0
Followers:	6

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