Generic cipher wrapper for mbed TLS. More...

#include "mbedtls/config.h"
#include "mbedtls/cipher.h"
#include "mbedtls/cipher_internal.h"
#include <stdlib.h>
#include <string.h>
#include "mbedtls/gcm.h"
#include "mbedtls/ccm.h"
#include "mbedtls/platform.h"
#include "arc4_alt.h"

Include dependency graph for cipher.c:

Macros
#define	MBEDTLS_CIPHER_MODE_STREAM

Functions
const int *	mbedtls_cipher_list (void)
	Returns 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)
	Returns 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)
	Returns 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)
	Returns the cipher information structure associated with the given cipher id, key size and mode. More...

void	mbedtls_cipher_init (mbedtls_cipher_context_t *ctx)
	Initialize a cipher_context (as NONE) More...

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. More...

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. More...

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. More...

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. More...

int	mbedtls_cipher_reset (mbedtls_cipher_context_t *ctx)
	Finish preparation of the given context. More...

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(). More...

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) More...

static void	add_pkcs_padding (unsigned char *output, size_t output_len, size_t data_len)

static int	get_pkcs_padding (unsigned char input, size_t input_len, size_t data_len)

static void	add_one_and_zeros_padding (unsigned char *output, size_t output_len, size_t data_len)

static int	get_one_and_zeros_padding (unsigned char input, size_t input_len, size_t data_len)

static void	add_zeros_and_len_padding (unsigned char *output, size_t output_len, size_t data_len)

static int	get_zeros_and_len_padding (unsigned char input, size_t input_len, size_t data_len)

static void	add_zeros_padding (unsigned char *output, size_t output_len, size_t data_len)

static int	get_zeros_padding (unsigned char input, size_t input_len, size_t data_len)

static int	get_no_padding (unsigned char input, size_t input_len, size_t data_len)

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. More...

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.) More...

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(). More...

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(). 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)
	Generic all-in-one encryption/decryption (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)
	Generic autenticated encryption (AEAD ciphers). 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)
	Generic autenticated decryption (AEAD ciphers). More...

Variables
static int	supported_init = 0

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

◆ MBEDTLS_CIPHER_MODE_STREAM

#define MBEDTLS_CIPHER_MODE_STREAM

Function Documentation

◆ add_one_and_zeros_padding()

static void add_one_and_zeros_padding	(	unsigned char *	output,
		size_t	output_len,
		size_t	data_len
	)

static

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◆ add_pkcs_padding()

static void add_pkcs_padding	(	unsigned char *	output,
		size_t	output_len,
		size_t	data_len
	)

static

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◆ add_zeros_and_len_padding()

static void add_zeros_and_len_padding	(	unsigned char *	output,
		size_t	output_len,
		size_t	data_len
	)

static

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◆ add_zeros_padding()

static void add_zeros_padding	(	unsigned char *	output,
		size_t	output_len,
		size_t	data_len
	)

static

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◆ get_no_padding()

static int get_no_padding	(	unsigned char *	input,
		size_t	input_len,
		size_t *	data_len
	)

static

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◆ get_one_and_zeros_padding()

static int get_one_and_zeros_padding	(	unsigned char *	input,
		size_t	input_len,
		size_t *	data_len
	)

static

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◆ get_pkcs_padding()

static int get_pkcs_padding	(	unsigned char *	input,
		size_t	input_len,
		size_t *	data_len
	)

static

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◆ get_zeros_and_len_padding()

static int get_zeros_and_len_padding	(	unsigned char *	input,
		size_t	input_len,
		size_t *	data_len
	)

static

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◆ get_zeros_padding()

static int get_zeros_padding	(	unsigned char *	input,
		size_t	input_len,
		size_t *	data_len
	)

static

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◆ 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
	)

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.

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◆ 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
	)

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.

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◆ mbedtls_cipher_check_tag()

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.

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◆ 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
	)

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.

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◆ mbedtls_cipher_finish()

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.

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◆ mbedtls_cipher_free()

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.

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◆ mbedtls_cipher_info_from_string()

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.

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◆ mbedtls_cipher_info_from_type()

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.

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◆ 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
	)

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.

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◆ mbedtls_cipher_init()

void mbedtls_cipher_init ( mbedtls_cipher_context_t * ctx )

Initialize a cipher_context (as NONE)

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◆ mbedtls_cipher_list()

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.

◆ mbedtls_cipher_reset()

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.

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◆ mbedtls_cipher_set_iv()

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.

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◆ mbedtls_cipher_set_padding_mode()

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.

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◆ mbedtls_cipher_setkey()

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.

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◆ mbedtls_cipher_setup()

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.

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◆ 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
	)

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.

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◆ mbedtls_cipher_update_ad()

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.

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◆ mbedtls_cipher_write_tag()

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.

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Variable Documentation

◆ supported_init

int supported_init = 0

static

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ MBEDTLS_CIPHER_MODE_STREAM

Function Documentation

◆ add_one_and_zeros_padding()

◆ add_pkcs_padding()

◆ add_zeros_and_len_padding()

◆ add_zeros_padding()

◆ get_no_padding()

◆ get_one_and_zeros_padding()

◆ get_pkcs_padding()

◆ get_zeros_and_len_padding()

◆ get_zeros_padding()

◆ mbedtls_cipher_auth_decrypt()

◆ mbedtls_cipher_auth_encrypt()

◆ mbedtls_cipher_check_tag()

◆ 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_set_padding_mode()

◆ mbedtls_cipher_setkey()

◆ mbedtls_cipher_setup()

◆ mbedtls_cipher_update()

◆ mbedtls_cipher_update_ad()

◆ mbedtls_cipher_write_tag()

Variable Documentation

◆ supported_init