Generic cipher wrapper for mbed TLS. More...

#include "config.h"
#include "cipher.h"
#include "cipher_internal.h"
#include "platform_util.h"
#include <stdlib.h>
#include <string.h>
#include "ccm.h"
#include "platform.h"

Include dependency graph for cipher.c:

Macros
#define	CIPHER_VALIDATE_RET(cond) MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA )

#define	CIPHER_VALIDATE(cond) MBEDTLS_INTERNAL_VALIDATE( cond )

Functions
const int *	mbedtls_cipher_list (void)
	This function retrieves the list of ciphers supported by the generic cipher module. More...

const mbedtls_cipher_info_t *	mbedtls_cipher_info_from_type (const mbedtls_cipher_type_t cipher_type)
	This function retrieves the cipher-information structure associated with the given cipher type. More...

const mbedtls_cipher_info_t *	mbedtls_cipher_info_from_string (const char *cipher_name)
	This function retrieves the cipher-information structure associated with the given cipher name. More...

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)
	This function retrieves the cipher-information structure associated with the given cipher ID, key size and mode. More...

void	mbedtls_cipher_init (mbedtls_cipher_context_t *ctx)
	This function initializes a `cipher_context` as NONE. More...

void	mbedtls_cipher_free (mbedtls_cipher_context_t *ctx)
	This function frees and clears the cipher-specific context of `ctx`. Freeing `ctx` itself remains the responsibility of the caller. More...

int	mbedtls_cipher_setup (mbedtls_cipher_context_t ctx, const mbedtls_cipher_info_t cipher_info)
	This function initializes and fills the cipher-context structure with the appropriate values. It also clears the structure. More...

int	mbedtls_cipher_setkey (mbedtls_cipher_context_t ctx, const unsigned char key, int key_bitlen, const mbedtls_operation_t operation)
	This function sets the key to use with the given context. More...

int	mbedtls_cipher_set_iv (mbedtls_cipher_context_t ctx, const unsigned char iv, size_t iv_len)
	This function sets the initialization vector (IV) or nonce. More...

int	mbedtls_cipher_reset (mbedtls_cipher_context_t *ctx)
	This function resets the cipher state. More...

int	mbedtls_cipher_update (mbedtls_cipher_context_t ctx, const unsigned char input, size_t ilen, unsigned char output, size_t olen)
	The generic cipher update function. It encrypts or decrypts using the given cipher context. Writes as many block-sized blocks of data as possible to output. Any data that cannot be written immediately is either added to the next block, or flushed when mbedtls_cipher_finish() is called. Exception: For MBEDTLS_MODE_ECB, expects a single block in size. For example, 16 Bytes for AES. More...

int	mbedtls_cipher_finish (mbedtls_cipher_context_t ctx, unsigned char output, size_t *olen)
	The generic cipher finalization function. If data still needs to be flushed from an incomplete block, the data contained in it is padded to the size of the last block, and written to the `output` buffer. More...

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)
	The generic all-in-one encryption/decryption function, for all ciphers except AEAD constructs. More...

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)
	The generic autenticated encryption (AEAD) function. More...

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)
	The generic autenticated decryption (AEAD) function. More...

Detailed Description

Generic cipher wrapper for mbed TLS.

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

Macro Definition Documentation

◆ CIPHER_VALIDATE

#define CIPHER_VALIDATE ( cond ) MBEDTLS_INTERNAL_VALIDATE( cond )

◆ CIPHER_VALIDATE_RET

#define CIPHER_VALIDATE_RET ( cond ) MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA )

Function Documentation

◆ mbedtls_cipher_auth_decrypt()

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
	)

The generic autenticated decryption (AEAD) function.

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

Parameters

ctx	The generic cipher context. This must be initialized and and bound to a key.
iv	The IV to use, or NONCE_COUNTER for CTR-mode ciphers. This must be a readable buffer of at least `iv_len` Bytes.
iv_len	The IV length for ciphers with variable-size IV. This parameter is discarded by ciphers with fixed-size IV.
ad	The additional data to be authenticated. This must be a readable buffer of at least `ad_len` Bytes.
ad_len	The length of `ad`.
input	The buffer holding the input data. This must be a readable buffer of at least `ilen` Bytes.
ilen	The length of the input data.
output	The buffer for the output data. This must be able to hold at least `ilen` Bytes.
olen	The length of the output data, to be updated with the actual number of Bytes written. This must not be `NULL`.
tag	The buffer holding the authentication tag. This must be a readable buffer of at least `tag_len` Bytes.
tag_len	The length of the authentication tag.

Returns: 0 on success.; MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on parameter-verification failure.; MBEDTLS_ERR_CIPHER_AUTH_FAILED if data is not authentic.; A cipher-specific error code on failure.

◆ mbedtls_cipher_auth_encrypt()

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
	)

The generic autenticated encryption (AEAD) function.

Parameters

ctx	The generic cipher context. This must be initialized and bound to a key.
iv	The IV to use, or NONCE_COUNTER for CTR-mode ciphers. This must be a readable buffer of at least `iv_len` Bytes.
iv_len	The IV length for ciphers with variable-size IV. This parameter is discarded by ciphers with fixed-size IV.
ad	The additional data to authenticate. This must be a readable buffer of at least `ad_len` Bytes.
ad_len	The length of `ad`.
input	The buffer holding the input data. This must be a readable buffer of at least `ilen` Bytes.
ilen	The length of the input data.
output	The buffer for the output data. This must be able to hold at least `ilen` Bytes.
olen	The length of the output data, to be updated with the actual number of Bytes written. This must not be `NULL`.
tag	The buffer for the authentication tag. This must be a writable buffer of at least `tag_len` Bytes.
tag_len	The desired length of the authentication tag.

Returns: 0 on success.; MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on parameter-verification failure.; A cipher-specific error code on failure.

◆ mbedtls_cipher_crypt()

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
	)

The generic all-in-one encryption/decryption function, for all ciphers except AEAD constructs.

Parameters

ctx	The generic cipher context. This must be initialized.
iv	The IV to use, or NONCE_COUNTER for CTR-mode ciphers. This must be a readable buffer of at least `iv_len` Bytes.
iv_len	The IV length for ciphers with variable-size IV. This parameter is discarded by ciphers with fixed-size IV.
input	The buffer holding the input data. This must be a readable buffer of at least `ilen` Bytes.
ilen	The length of the input data in Bytes.
output	The buffer for the output data. This must be able to hold at least `ilen + block_size`. This must not be the same buffer as `input`.
olen	The length of the output data, to be updated with the actual number of Bytes written. This must not be `NULL`.

Note: Some ciphers do not use IVs nor nonce. For these ciphers, use iv = NULL and iv_len = 0.

Returns: 0 on success.; MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on parameter-verification failure.; MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption expecting a full block but not receiving one.; MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding while decrypting.; A cipher-specific error code on failure.

◆ mbedtls_cipher_finish()

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

The generic cipher finalization function. If data still needs to be flushed from an incomplete block, the data contained in it is padded to the size of the last block, and written to the output buffer.

Parameters

ctx	The generic cipher context. This must be initialized and bound to a key.
output	The buffer to write data to. This needs to be a writable buffer of at least `block_size` Bytes.
olen	The length of the data written to the `output` buffer. This may not be `NULL`.

Returns: 0 on success.; MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on parameter-verification failure.; MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption expecting a full block but not receiving one.; MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding while decrypting.; A cipher-specific error code on failure.

◆ mbedtls_cipher_free()

void mbedtls_cipher_free ( mbedtls_cipher_context_t * ctx )

This function frees and clears the cipher-specific context of ctx. Freeing ctx itself remains the responsibility of the caller.

Parameters

ctx	The context to be freed. If this is `NULL`, the function has no effect, otherwise this must point to an initialized context.

Here is the call graph for this function:

◆ mbedtls_cipher_info_from_string()

const mbedtls_cipher_info_t* mbedtls_cipher_info_from_string ( const char * cipher_name )

This function retrieves the cipher-information structure associated with the given cipher name.

Parameters

cipher_name Name of the cipher to search for. This must not be NULL.

Returns: The cipher information structure associated with the given cipher_name.; NULL if the associated cipher information is not found.

◆ mbedtls_cipher_info_from_type()

const mbedtls_cipher_info_t* mbedtls_cipher_info_from_type ( const mbedtls_cipher_type_t cipher_type )

This function retrieves 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.; NULL if the associated cipher information is not found.

◆ mbedtls_cipher_info_from_values()

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
	)

This function retrieves the cipher-information structure associated with the given cipher ID, key size and mode.

Parameters

cipher_id	The ID of the cipher to search for. For example, MBEDTLS_CIPHER_ID_AES.
key_bitlen	The length of the key in bits.
mode	The cipher mode. For example, MBEDTLS_MODE_CBC.

Returns: The cipher information structure associated with the given cipher_id.; NULL if the associated cipher information is not found.

◆ mbedtls_cipher_init()

void mbedtls_cipher_init ( mbedtls_cipher_context_t * ctx )

This function initializes a cipher_context as NONE.

Parameters

ctx	The context to be initialized. This must not be `NULL`.

◆ mbedtls_cipher_list()

const int* mbedtls_cipher_list ( void )

This function retrieves the list of ciphers supported by the generic cipher module.

Returns: A statically-allocated array of ciphers. The last entry is zero.

◆ mbedtls_cipher_reset()

int mbedtls_cipher_reset ( mbedtls_cipher_context_t * ctx )

This function resets the cipher state.

Parameters

ctx	The generic cipher context. This must be initialized.

Returns: 0 on success.; MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on parameter-verification failure.

◆ mbedtls_cipher_set_iv()

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

This function sets the initialization vector (IV) or nonce.

Note: Some ciphers do not use IVs nor nonce. For these ciphers, this function has no effect.

Parameters

ctx	The generic cipher context. This must be initialized and bound to a cipher information structure.
iv	The IV to use, or NONCE_COUNTER for CTR-mode ciphers. This must be a readable buffer of at least `iv_len` Bytes.
iv_len	The IV length for ciphers with variable-size IV. This parameter is discarded by ciphers with fixed-size IV.

Returns: 0 on success.; MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on parameter-verification failure.

◆ mbedtls_cipher_setkey()

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

This function sets the key to use with the given context.

Parameters

ctx	The generic cipher context. This must be initialized and bound to a cipher information structure.
key	The key to use. This must be a readable buffer of at least `key_bitlen` Bits.
key_bitlen	The key length to use, in Bits.
operation	The operation that the key will be used for: MBEDTLS_ENCRYPT or MBEDTLS_DECRYPT.

Returns: 0 on success.; MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on parameter-verification failure.; A cipher-specific error code on failure.

◆ mbedtls_cipher_setup()

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

This function initializes and fills the cipher-context structure with the appropriate values. It also clears the structure.

Parameters

ctx	The context to initialize. This must be initialized.
cipher_info	The cipher to use.

Returns: 0 on success.; MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on parameter-verification failure.; MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the cipher-specific context fails.

◆ mbedtls_cipher_update()

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

The generic cipher update function. It encrypts or decrypts using the given cipher context. Writes as many block-sized blocks of data as possible to output. Any data that cannot be written immediately is either added to the next block, or flushed when mbedtls_cipher_finish() is called. Exception: For MBEDTLS_MODE_ECB, expects a single block in size. For example, 16 Bytes for AES.

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

Parameters

ctx	The generic cipher context. This must be initialized and bound to a key.
input	The buffer holding the input data. This must be a readable buffer of at least `ilen` Bytes.
ilen	The length of the input data.
output	The buffer for the output data. This must be able to hold at least `ilen + block_size`. This must not be the same buffer as `input`.
olen	The length of the output data, to be updated with the actual number of Bytes written. This must not be `NULL`.

Returns: 0 on success.; MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on parameter-verification failure.; MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE on an unsupported mode for a cipher.; A cipher-specific error code on failure.

Macros

Functions

Detailed Description

Macro Definition Documentation

◆ CIPHER_VALIDATE

◆ CIPHER_VALIDATE_RET

Function Documentation

◆ mbedtls_cipher_auth_decrypt()

◆ mbedtls_cipher_auth_encrypt()

◆ mbedtls_cipher_crypt()

◆ mbedtls_cipher_finish()

◆ mbedtls_cipher_free()

◆ mbedtls_cipher_info_from_string()

◆ mbedtls_cipher_info_from_type()

◆ mbedtls_cipher_info_from_values()

◆ mbedtls_cipher_init()

◆ mbedtls_cipher_list()

◆ mbedtls_cipher_reset()

◆ mbedtls_cipher_set_iv()

◆ mbedtls_cipher_setkey()

◆ mbedtls_cipher_setup()

◆ mbedtls_cipher_update()