This file contains the generic message-digest wrapper. More...

#include "mbedtls/private_access.h"
#include <stddef.h>
#include "mbedtls/build_info.h"
#include "mbedtls/platform_util.h"

Include dependency graph for md.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Data Structures
struct	mbedtls_md_context_t

Macros
#define	MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE -0x5080

#define	MBEDTLS_ERR_MD_BAD_INPUT_DATA -0x5100

#define	MBEDTLS_ERR_MD_ALLOC_FAILED -0x5180

#define	MBEDTLS_ERR_MD_FILE_IO_ERROR -0x5200

#define	MBEDTLS_MD_MAX_SIZE 64 /* longest known is SHA512 */

#define	MBEDTLS_MD_MAX_BLOCK_SIZE 128

Typedefs
typedef struct mbedtls_md_info_t	mbedtls_md_info_t

typedef struct mbedtls_md_context_t	mbedtls_md_context_t

Enumerations
enum	mbedtls_md_type_t { MBEDTLS_MD_NONE =0, MBEDTLS_MD_MD5, MBEDTLS_MD_SHA1, MBEDTLS_MD_SHA224, MBEDTLS_MD_SHA256, MBEDTLS_MD_SHA384, MBEDTLS_MD_SHA512, MBEDTLS_MD_RIPEMD160 }
	Supported message digests. More...

Functions
const int *	mbedtls_md_list (void)
	This function returns the list of digests supported by the generic digest module. More...

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. More...

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. More...

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. More...

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. More...

MBEDTLS_CHECK_RETURN_TYPICAL 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. More...

MBEDTLS_CHECK_RETURN_TYPICAL 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. More...

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. More...

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. More...

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. More...

MBEDTLS_CHECK_RETURN_TYPICAL int	mbedtls_md_starts (mbedtls_md_context_t *ctx)
	This function starts a message-digest computation. More...

MBEDTLS_CHECK_RETURN_TYPICAL 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. More...

MBEDTLS_CHECK_RETURN_TYPICAL 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. More...

MBEDTLS_CHECK_RETURN_TYPICAL 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. More...

MBEDTLS_CHECK_RETURN_TYPICAL 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. More...

MBEDTLS_CHECK_RETURN_TYPICAL 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. More...

MBEDTLS_CHECK_RETURN_TYPICAL 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. More...

MBEDTLS_CHECK_RETURN_TYPICAL 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. More...

MBEDTLS_CHECK_RETURN_TYPICAL 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. More...

MBEDTLS_CHECK_RETURN_TYPICAL 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. More...

MBEDTLS_CHECK_RETURN_TYPICAL int	mbedtls_md_process (mbedtls_md_context_t ctx, const unsigned char data)

Detailed Description

This file contains the generic message-digest wrapper.

Author: Adriaan de Jong dejon.nosp@m.g@fo.nosp@m.x-it..nosp@m.com

Definition in file md.h.

Macro Definition Documentation

#define MBEDTLS_ERR_MD_ALLOC_FAILED -0x5180

Failed to allocate memory.

Definition at line 39 of file md.h.

#define MBEDTLS_ERR_MD_BAD_INPUT_DATA -0x5100

Bad input parameters to function.

Definition at line 37 of file md.h.

#define MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE -0x5080

The selected feature is not available.

Definition at line 35 of file md.h.

#define MBEDTLS_ERR_MD_FILE_IO_ERROR -0x5200

Opening or reading of file failed.

Definition at line 41 of file md.h.

#define MBEDTLS_MD_MAX_BLOCK_SIZE 128

Definition at line 73 of file md.h.

#define MBEDTLS_MD_MAX_SIZE 64 /* longest known is SHA512 */

Definition at line 67 of file md.h.

Typedef Documentation

typedef struct mbedtls_md_context_t mbedtls_md_context_t

The generic message-digest context.

typedef struct mbedtls_md_info_t mbedtls_md_info_t

Opaque struct.

Constructed using either mbedtls_md_info_from_string or mbedtls_md_info_from_type.

Fields can be accessed with mbedtls_md_get_size, mbedtls_md_get_type and mbedtls_md_get_name.

Definition at line 88 of file md.h.

Enumeration Type Documentation

enum mbedtls_md_type_t

Supported message digests.

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

Enumerator
MBEDTLS_MD_NONE	None.
MBEDTLS_MD_MD5	The MD5 message digest.
MBEDTLS_MD_SHA1	The SHA-1 message digest.
MBEDTLS_MD_SHA224	The SHA-224 message digest.
MBEDTLS_MD_SHA256	The SHA-256 message digest.
MBEDTLS_MD_SHA384	The SHA-384 message digest.
MBEDTLS_MD_SHA512	The SHA-512 message digest.
MBEDTLS_MD_RIPEMD160	The RIPEMD-160 message digest.

Definition at line 55 of file md.h.

Function Documentation

MBEDTLS_CHECK_RETURN_TYPICAL 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.; MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification failure.

MBEDTLS_CHECK_RETURN_TYPICAL 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-verification failure.

MBEDTLS_CHECK_RETURN_TYPICAL 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 on an I/O error accessing the file pointed by path.; MBEDTLS_ERR_MD_BAD_INPUT_DATA if md_info was NULL.

MBEDTLS_CHECK_RETURN_TYPICAL 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.; MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification failure.

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().

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.

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.

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.

MBEDTLS_CHECK_RETURN_TYPICAL 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.; MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification failure.

MBEDTLS_CHECK_RETURN_TYPICAL 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.; MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification failure.

MBEDTLS_CHECK_RETURN_TYPICAL 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.; MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification failure.

MBEDTLS_CHECK_RETURN_TYPICAL 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.; MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification failure.

MBEDTLS_CHECK_RETURN_TYPICAL 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.; MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification failure.

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.; NULL if the associated message-digest information is not found.

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.; NULL if the associated message-digest information is not found.

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.

const int* mbedtls_md_list ( void )

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

Note: The list starts with the strongest available hashes.

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.

MBEDTLS_CHECK_RETURN_TYPICAL int mbedtls_md_process	(	mbedtls_md_context_t *	ctx,
		const unsigned char *	data
	)

MBEDTLS_CHECK_RETURN_TYPICAL 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	Defines if HMAC is used. 0: HMAC is not used (saves some memory), or non-zero: HMAC is used with this context.

Returns: 0 on success.; MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification failure.; MBEDTLS_ERR_MD_ALLOC_FAILED on memory-allocation failure.

MBEDTLS_CHECK_RETURN_TYPICAL 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 on parameter-verification failure.

MBEDTLS_CHECK_RETURN_TYPICAL 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 on parameter-verification failure.

Data Structures

Macros

Typedefs

Enumerations

Functions

Detailed Description

Macro Definition Documentation

Typedef Documentation

Enumeration Type Documentation

Function Documentation