Generic cipher wrapper. More...

Data Structures
struct	mbedtls_cipher_info_t
	Cipher information. More...
struct	mbedtls_cipher_context_t
	Generic cipher context. More...
Typedefs
typedef struct mbedtls_cipher_base_t	mbedtls_cipher_base_t
	Base cipher information (opaque struct).
typedef struct mbedtls_cmac_context_t	mbedtls_cmac_context_t
	CMAC context (opaque struct).
Enumerations
enum	mbedtls_cipher_padding_t { MBEDTLS_PADDING_PKCS7 = 0, MBEDTLS_PADDING_ONE_AND_ZEROS, MBEDTLS_PADDING_ZEROS_AND_LEN, MBEDTLS_PADDING_ZEROS, MBEDTLS_PADDING_NONE }
enum	{ MBEDTLS_KEY_LENGTH_NONE = 0, MBEDTLS_KEY_LENGTH_DES = 64, MBEDTLS_KEY_LENGTH_DES_EDE = 128, MBEDTLS_KEY_LENGTH_DES_EDE3 = 192 }
Functions
const int *	mbedtls_cipher_list (void)
	Returns the list of ciphers supported by the generic cipher module.
const mbedtls_cipher_info_t *	mbedtls_cipher_info_from_string (const char *cipher_name)
	Returns the cipher information structure associated with the given cipher name.
const mbedtls_cipher_info_t *	mbedtls_cipher_info_from_type (const mbedtls_cipher_type_t cipher_type)
	Returns the cipher information structure associated with the given cipher type.
const mbedtls_cipher_info_t *	mbedtls_cipher_info_from_values (const mbedtls_cipher_id_t cipher_id, int key_bitlen, const mbedtls_cipher_mode_t mode)
	Returns the cipher information structure associated with the given cipher id, key size and mode.
void	mbedtls_cipher_init (mbedtls_cipher_context_t *ctx)
	Initialize a cipher_context (as NONE)
void	mbedtls_cipher_free (mbedtls_cipher_context_t *ctx)
	Free and clear the cipher-specific context of ctx.
int	mbedtls_cipher_setup (mbedtls_cipher_context_t ctx, const mbedtls_cipher_info_t cipher_info)
	Initialises and fills the cipher context structure with the appropriate values.
static unsigned int	mbedtls_cipher_get_block_size (const mbedtls_cipher_context_t *ctx)
	Returns the block size of the given cipher.
static mbedtls_cipher_mode_t	mbedtls_cipher_get_cipher_mode (const mbedtls_cipher_context_t *ctx)
	Returns the mode of operation for the cipher.
static int	mbedtls_cipher_get_iv_size (const mbedtls_cipher_context_t *ctx)
	Returns the size of the cipher's IV/NONCE in bytes.
static mbedtls_cipher_type_t	mbedtls_cipher_get_type (const mbedtls_cipher_context_t *ctx)
	Returns the type of the given cipher.
static const char *	mbedtls_cipher_get_name (const mbedtls_cipher_context_t *ctx)
	Returns the name of the given cipher, as a string.
static int	mbedtls_cipher_get_key_bitlen (const mbedtls_cipher_context_t *ctx)
	Returns the key length of the cipher.
static mbedtls_operation_t	mbedtls_cipher_get_operation (const mbedtls_cipher_context_t *ctx)
	Returns the operation of the given cipher.
int	mbedtls_cipher_setkey (mbedtls_cipher_context_t ctx, const unsigned char key, int key_bitlen, const mbedtls_operation_t operation)
	Set the key to use with the given context.
int	mbedtls_cipher_set_padding_mode (mbedtls_cipher_context_t *ctx, mbedtls_cipher_padding_t mode)
	Set padding mode, for cipher modes that use padding.
int	mbedtls_cipher_set_iv (mbedtls_cipher_context_t ctx, const unsigned char iv, size_t iv_len)
	Set the initialization vector (IV) or nonce.
int	mbedtls_cipher_reset (mbedtls_cipher_context_t *ctx)
	Finish preparation of the given context.
int	mbedtls_cipher_update_ad (mbedtls_cipher_context_t ctx, const unsigned char ad, size_t ad_len)
	Add additional data (for AEAD ciphers).
int	mbedtls_cipher_update (mbedtls_cipher_context_t ctx, const unsigned char input, size_t ilen, unsigned char output, size_t olen)
	Generic cipher update function.
int	mbedtls_cipher_finish (mbedtls_cipher_context_t ctx, unsigned char output, size_t *olen)
	Generic cipher finalisation function.
int	mbedtls_cipher_write_tag (mbedtls_cipher_context_t ctx, unsigned char tag, size_t tag_len)
	Write tag for AEAD ciphers.
int	mbedtls_cipher_check_tag (mbedtls_cipher_context_t ctx, const unsigned char tag, size_t tag_len)
	Check tag for AEAD ciphers.
int	mbedtls_cipher_crypt (mbedtls_cipher_context_t ctx, const unsigned char iv, size_t iv_len, const unsigned char input, size_t ilen, unsigned char output, size_t *olen)
	Generic all-in-one encryption/decryption (for all ciphers except AEAD constructs).
int	mbedtls_cipher_auth_encrypt (mbedtls_cipher_context_t ctx, const unsigned char iv, size_t iv_len, const unsigned char ad, size_t ad_len, const unsigned char input, size_t ilen, unsigned char output, size_t olen, unsigned char *tag, size_t tag_len)
	Generic autenticated encryption (AEAD ciphers).
int	mbedtls_cipher_auth_decrypt (mbedtls_cipher_context_t ctx, const unsigned char iv, size_t iv_len, const unsigned char ad, size_t ad_len, const unsigned char input, size_t ilen, unsigned char output, size_t olen, const unsigned char *tag, size_t tag_len)
	Generic autenticated decryption (AEAD ciphers).

Detailed Description

Generic cipher wrapper.

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

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

This file is part of mbed TLS (https://tls.mbed.org)

Definition in file cipher.h.

Typedef Documentation

typedef struct mbedtls_cipher_base_t mbedtls_cipher_base_t

Base cipher information (opaque struct).

Definition at line 177 of file cipher.h.

typedef struct mbedtls_cmac_context_t mbedtls_cmac_context_t

CMAC context (opaque struct).

Definition at line 182 of file cipher.h.

Enumeration Type Documentation

anonymous enum

Enumerator:

MBEDTLS_KEY_LENGTH_NONE	Undefined key length.
MBEDTLS_KEY_LENGTH_DES	Key length, in bits (including parity), for DES keys.
MBEDTLS_KEY_LENGTH_DES_EDE	Key length, in bits (including parity), for DES in two key EDE.
MBEDTLS_KEY_LENGTH_DES_EDE3	Key length, in bits (including parity), for DES in three-key EDE.

Definition at line 158 of file cipher.h.

enum mbedtls_cipher_padding_t

Enumerator:

MBEDTLS_PADDING_PKCS7	PKCS7 padding (default)
MBEDTLS_PADDING_ONE_AND_ZEROS	ISO/IEC 7816-4 padding.
MBEDTLS_PADDING_ZEROS_AND_LEN	ANSI X.923 padding.
MBEDTLS_PADDING_ZEROS	zero padding (not reversible!)
MBEDTLS_PADDING_NONE	never pad (full blocks only)

Definition at line 144 of file cipher.h.

Function Documentation

int mbedtls_cipher_auth_decrypt	(	mbedtls_cipher_context_t *	ctx,
		const unsigned char *	iv,
		size_t	iv_len,
		const unsigned char *	ad,
		size_t	ad_len,
		const unsigned char *	input,
		size_t	ilen,
		unsigned char *	output,
		size_t *	olen,
		const unsigned char *	tag,
		size_t	tag_len
	)

Generic autenticated decryption (AEAD ciphers).

Parameters:

ctx	generic cipher context
iv	IV to use (or NONCE_COUNTER for CTR-mode ciphers)
iv_len	IV length for ciphers with variable-size IV; discarded by ciphers with fixed-size IV.
ad	Additional data to be authenticated.
ad_len	Length of ad.
input	buffer holding the input data
ilen	length of the input data
output	buffer for the output data. Should be able to hold at least ilen.
olen	length of the output data, will be filled with the actual number of bytes written.
tag	buffer holding the authentication tag
tag_len	length of the authentication tag

Returns:: 0 on success, or MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA, or MBEDTLS_ERR_CIPHER_AUTH_FAILED if data isn't authentic, or a cipher specific error code.

Note:: If the data is not authentic, then the output buffer is zeroed out to prevent the unauthentic plaintext to be used by mistake, making this interface safer.

Definition at line 873 of file cipher.c.

int mbedtls_cipher_auth_encrypt	(	mbedtls_cipher_context_t *	ctx,
		const unsigned char *	iv,
		size_t	iv_len,
		const unsigned char *	ad,
		size_t	ad_len,
		const unsigned char *	input,
		size_t	ilen,
		unsigned char *	output,
		size_t *	olen,
		unsigned char *	tag,
		size_t	tag_len
	)

Generic autenticated encryption (AEAD ciphers).

Parameters:

ctx	generic cipher context
iv	IV to use (or NONCE_COUNTER for CTR-mode ciphers)
iv_len	IV length for ciphers with variable-size IV; discarded by ciphers with fixed-size IV.
ad	Additional data to authenticate.
ad_len	Length of ad.
input	buffer holding the input data
ilen	length of the input data
output	buffer for the output data. Should be able to hold at least ilen.
olen	length of the output data, will be filled with the actual number of bytes written.
tag	buffer for the authentication tag
tag_len	desired tag length

Returns:: 0 on success, or MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA, or a cipher specific error code.

Definition at line 841 of file cipher.c.

int mbedtls_cipher_check_tag	(	mbedtls_cipher_context_t *	ctx,
		const unsigned char *	tag,
		size_t	tag_len
	)

Check tag for AEAD ciphers.

Currently only supported with GCM. Must be called after mbedtls_cipher_finish().

Parameters:

ctx	Generic cipher context
tag	Buffer holding the tag
tag_len	Length of the tag to check

Returns:: 0 on success, or a specific error code.

Definition at line 769 of file cipher.c.

int mbedtls_cipher_crypt	(	mbedtls_cipher_context_t *	ctx,
		const unsigned char *	iv,
		size_t	iv_len,
		const unsigned char *	input,
		size_t	ilen,
		unsigned char *	output,
		size_t *	olen
	)

Generic all-in-one encryption/decryption (for all ciphers except AEAD constructs).

Parameters:

ctx	generic cipher context
iv	IV to use (or NONCE_COUNTER for CTR-mode ciphers)
iv_len	IV length for ciphers with variable-size IV; discarded by ciphers with fixed-size IV.
input	buffer holding the input data
ilen	length of the input data
output	buffer for the output data. Should be able to hold at least ilen + block_size. Cannot be the same buffer as input!
olen	length of the output data, will be filled with the actual number of bytes written.

Note:: Some ciphers don't use IVs nor NONCE. For these ciphers, use iv = NULL and iv_len = 0.

Returns:: 0 on success, or MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA, or MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED if decryption expected a full block but was not provided one, or MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding while decrypting, or a cipher specific error code.

Definition at line 812 of file cipher.c.

int mbedtls_cipher_finish	(	mbedtls_cipher_context_t *	ctx,
		unsigned char *	output,
		size_t *	olen
	)

Generic cipher finalisation function.

If data still needs to be flushed from an incomplete block, data contained within it will be padded with the size of the last block, and written to the output buffer.

Parameters:

ctx	Generic cipher context
output	buffer to write data to. Needs block_size available.
olen	length of the data written to the output buffer.

Returns:: 0 on success, MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if parameter verification fails, MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED if decryption expected a full block but was not provided one, MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding while decrypting or a cipher specific error code.

Definition at line 626 of file cipher.c.

void mbedtls_cipher_free ( mbedtls_cipher_context_t * ctx )

Free and clear the cipher-specific context of ctx.

Freeing ctx itself remains the responsibility of the caller.

Definition at line 136 of file cipher.c.

static unsigned int mbedtls_cipher_get_block_size ( const mbedtls_cipher_context_t * ctx ) [static]

Returns the block size of the given cipher.

Parameters:

ctx	cipher's context. Must have been initialised.

Returns:: size of the cipher's blocks, or 0 if ctx has not been initialised.

Definition at line 340 of file cipher.h.

static mbedtls_cipher_mode_t mbedtls_cipher_get_cipher_mode ( const mbedtls_cipher_context_t * ctx ) [static]

Returns the mode of operation for the cipher.

(e.g. MBEDTLS_MODE_CBC)

Parameters:

ctx	cipher's context. Must have been initialised.

Returns:: mode of operation, or MBEDTLS_MODE_NONE if ctx has not been initialised.

Definition at line 357 of file cipher.h.

static int mbedtls_cipher_get_iv_size ( const mbedtls_cipher_context_t * ctx ) [static]

Returns the size of the cipher's IV/NONCE in bytes.

Parameters:

ctx	cipher's context. Must have been initialised.

Returns:: If IV has not been set yet: (recommended) IV size (0 for ciphers not using IV/NONCE). If IV has already been set: actual size.

Definition at line 374 of file cipher.h.

static int mbedtls_cipher_get_key_bitlen ( const mbedtls_cipher_context_t * ctx ) [static]

Returns the key length of the cipher.

Parameters:

ctx	cipher's context. Must have been initialised.

Returns:: cipher's key length, in bits, or MBEDTLS_KEY_LENGTH_NONE if ctx has not been initialised.

Definition at line 425 of file cipher.h.

static const char* mbedtls_cipher_get_name ( const mbedtls_cipher_context_t * ctx ) [static]

Returns the name of the given cipher, as a string.

Parameters:

ctx	cipher's context. Must have been initialised.

Returns:: name of the cipher, or NULL if ctx was not initialised.

Definition at line 408 of file cipher.h.

static mbedtls_operation_t mbedtls_cipher_get_operation ( const mbedtls_cipher_context_t * ctx ) [static]

Returns the operation of the given cipher.

Parameters:

ctx	cipher's context. Must have been initialised.

Returns:: operation (MBEDTLS_ENCRYPT or MBEDTLS_DECRYPT), or MBEDTLS_OPERATION_NONE if ctx has not been initialised.

Definition at line 442 of file cipher.h.

static mbedtls_cipher_type_t mbedtls_cipher_get_type ( const mbedtls_cipher_context_t * ctx ) [static]

Returns the type of the given cipher.

Parameters:

ctx	cipher's context. Must have been initialised.

Returns:: type of the cipher, or MBEDTLS_CIPHER_NONE if ctx has not been initialised.

Definition at line 393 of file cipher.h.

const mbedtls_cipher_info_t* mbedtls_cipher_info_from_string ( const char * cipher_name )

Returns the cipher information structure associated with the given cipher name.

Parameters:

cipher_name Name of the cipher to search for.

Returns:: the cipher information structure associated with the given cipher_name, or NULL if not found.

Definition at line 102 of file cipher.c.

const mbedtls_cipher_info_t* mbedtls_cipher_info_from_type ( const mbedtls_cipher_type_t cipher_type )

Returns the cipher information structure associated with the given cipher type.

Parameters:

cipher_type Type of the cipher to search for.

Returns:: the cipher information structure associated with the given cipher_type, or NULL if not found.

Definition at line 91 of file cipher.c.

const mbedtls_cipher_info_t* mbedtls_cipher_info_from_values	(	const mbedtls_cipher_id_t	cipher_id,
		int	key_bitlen,
		const mbedtls_cipher_mode_t	mode
	)

Returns the cipher information structure associated with the given cipher id, key size and mode.

Parameters:

cipher_id	Id of the cipher to search for (e.g. MBEDTLS_CIPHER_ID_AES)
key_bitlen	Length of the key in bits
mode	Cipher mode (e.g. MBEDTLS_MODE_CBC)

Returns:: the cipher information structure associated with the given cipher_type, or NULL if not found.

Definition at line 116 of file cipher.c.

void mbedtls_cipher_init ( mbedtls_cipher_context_t * ctx )

Initialize a cipher_context (as NONE)

Definition at line 131 of file cipher.c.

const int* mbedtls_cipher_list ( void )

Returns the list of ciphers supported by the generic cipher module.

Returns:: a statically allocated array of ciphers, the last entry is 0.

Definition at line 70 of file cipher.c.

int mbedtls_cipher_reset ( mbedtls_cipher_context_t * ctx )

Finish preparation of the given context.

Parameters:

ctx	generic cipher context

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

Definition at line 243 of file cipher.c.

int mbedtls_cipher_set_iv	(	mbedtls_cipher_context_t *	ctx,
		const unsigned char *	iv,
		size_t	iv_len
	)

Set the initialization vector (IV) or nonce.

Parameters:

ctx	generic cipher context
iv	IV to use (or NONCE_COUNTER for CTR-mode ciphers)
iv_len	IV length for ciphers with variable-size IV; discarded by ciphers with fixed-size IV.

Returns:: 0 on success, or MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA

Note:: Some ciphers don't use IVs nor NONCE. For these ciphers, this function has no effect.

Definition at line 214 of file cipher.c.

int mbedtls_cipher_set_padding_mode	(	mbedtls_cipher_context_t *	ctx,
		mbedtls_cipher_padding_t	mode
	)

Set padding mode, for cipher modes that use padding.

(Default: PKCS7 padding.)

Parameters:

ctx	generic cipher context
mode	padding mode

Returns:: 0 on success, MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE if selected padding mode is not supported, or MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if the cipher mode does not support padding.

Definition at line 706 of file cipher.c.

int mbedtls_cipher_setkey	(	mbedtls_cipher_context_t *	ctx,
		const unsigned char *	key,
		int	key_bitlen,
		const mbedtls_operation_t	operation
	)

Set the key to use with the given context.

Parameters:

ctx	generic cipher context. May not be NULL. Must have been initialised using cipher_context_from_type or cipher_context_from_string.
key	The key to use.
key_bitlen	key length to use, in bits.
operation	Operation that the key will be used for, either MBEDTLS_ENCRYPT or MBEDTLS_DECRYPT.

Returns:: 0 on success, MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if parameter verification fails or a cipher specific error code.

Definition at line 181 of file cipher.c.

int mbedtls_cipher_setup	(	mbedtls_cipher_context_t *	ctx,
		const mbedtls_cipher_info_t *	cipher_info
	)

Initialises and fills the cipher context structure with the appropriate values.

Note:: Currently also clears structure. In future versions you will be required to call mbedtls_cipher_init() on the structure first.

Parameters:

ctx	context to initialise. May not be NULL.
cipher_info	cipher to use.

Returns:: 0 on success, MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on parameter failure, MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the cipher-specific context failed.

Definition at line 155 of file cipher.c.

int mbedtls_cipher_update	(	mbedtls_cipher_context_t *	ctx,
		const unsigned char *	input,
		size_t	ilen,
		unsigned char *	output,
		size_t *	olen
	)

Generic cipher update function.

Encrypts/decrypts using the given cipher context. Writes as many block size'd blocks of data as possible to output. Any data that cannot be written immediately will either be added to the next block, or flushed when cipher_final is called. Exception: for MBEDTLS_MODE_ECB, expects single block in size (e.g. 16 bytes for AES)

Parameters:

ctx	generic cipher context
input	buffer holding the input data
ilen	length of the input data
output	buffer for the output data. Should be able to hold at least ilen + block_size. Cannot be the same buffer as input!
olen	length of the output data, will be filled with the actual number of bytes written.

Returns:: 0 on success, MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if parameter verification fails, MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE on an unsupported mode for a cipher or a cipher specific error code.

Note:: If the underlying cipher is GCM, all calls to this function, except the last one before mbedtls_cipher_finish(), must have ilen a multiple of the block size.

Definition at line 270 of file cipher.c.

int mbedtls_cipher_update_ad	(	mbedtls_cipher_context_t *	ctx,
		const unsigned char *	ad,
		size_t	ad_len
	)

Add additional data (for AEAD ciphers).

Currently only supported with GCM. Must be called exactly once, after mbedtls_cipher_reset().

Parameters:

ctx	generic cipher context
ad	Additional data to use.
ad_len	Length of ad.

Returns:: 0 on success, or a specific error code.

Definition at line 254 of file cipher.c.

int mbedtls_cipher_write_tag	(	mbedtls_cipher_context_t *	ctx,
		unsigned char *	tag,
		size_t	tag_len
	)

Write tag for AEAD ciphers.

Currently only supported with GCM. Must be called after mbedtls_cipher_finish().

Parameters:

ctx	Generic cipher context
tag	buffer to write the tag
tag_len	Length of the tag to write

Returns:: 0 on success, or a specific error code.

Definition at line 754 of file cipher.c.

Type:	Program
Mbed OS support:	Mbed OS
Created:	23 Feb 2019
Imports:	43
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	0
Followers:	1

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cipher.h File Reference

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Detailed Description

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Enumeration Type Documentation

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