Generic cipher wrapper for mbed TLS. More...

Functions
const int *	mbedtls_cipher_list (void)
	This function retrieves the list of ciphers supported by the generic cipher module.
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.
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.
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.
void	mbedtls_cipher_init (mbedtls_cipher_context_t *ctx)
	This function initializes a `cipher_context` as NONE.
void	mbedtls_cipher_free (mbedtls_cipher_context_t *ctx)
	This function frees and clears the cipher-specific context of `ctx`.
int	mbedtls_cipher_setup (mbedtls_cipher_context_t ctx, const mbedtls_cipher_info_t cipher_info)
	This function initializes a cipher context for use with the given cipher primitive.
int	mbedtls_cipher_setup_psa (mbedtls_cipher_context_t ctx, const mbedtls_cipher_info_t cipher_info, size_t taglen)
	This function initializes a cipher context for PSA-based use with the given cipher primitive.
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.
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.
int	mbedtls_cipher_reset (mbedtls_cipher_context_t *ctx)
	This function resets the cipher state.
int	mbedtls_cipher_update_ad (mbedtls_cipher_context_t ctx, const unsigned char ad, size_t ad_len)
	This function adds 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)
	The generic cipher update function.
int	mbedtls_cipher_finish (mbedtls_cipher_context_t ctx, unsigned char output, size_t *olen)
	The generic cipher finalization function.
int	mbedtls_cipher_set_padding_mode (mbedtls_cipher_context_t *ctx, mbedtls_cipher_padding_t mode)
	This function sets the padding mode, for cipher modes that use padding.
int	mbedtls_cipher_write_tag (mbedtls_cipher_context_t ctx, unsigned char tag, size_t tag_len)
	This function writes a tag for AEAD ciphers.
int	mbedtls_cipher_check_tag (mbedtls_cipher_context_t ctx, const unsigned char tag, size_t tag_len)
	This function checks the 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)
	The generic all-in-one encryption/decryption function, 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)
	The generic autenticated encryption (AEAD) function.
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.

Detailed Description

Generic cipher wrapper for mbed TLS.

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.c.

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
	)

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.

Definition at line 1407 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
	)

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.

Definition at line 1304 of file cipher.c.

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

This function checks the tag for AEAD ciphers.

Currently supported with GCM and ChaCha20+Poly1305. This must be called after mbedtls_cipher_finish().

Parameters:

ctx	The generic cipher context. This must be initialized.
tag	The buffer holding the tag. This must be a readable buffer of at least `tag_len` Bytes.
tag_len	The length of the tag to check.

Returns:: 0 on success.; A specific error code on failure.

Definition at line 1133 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
	)

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.

Definition at line 1209 of file cipher.c.

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.

Definition at line 927 of file cipher.c.

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.

Definition at line 175 of file cipher.c.

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.

Definition at line 138 of file cipher.c.

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.

Definition at line 126 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
	)

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.

Definition at line 153 of file cipher.c.

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`.

Definition at line 169 of file cipher.c.

const int* mbedtls_cipher_list ( void )

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

For any cipher identifier in the returned list, you can obtain the corresponding generic cipher information structure via mbedtls_cipher_info_from_type(), which can then be used to prepare a cipher context via mbedtls_cipher_setup().

Returns:: A statically-allocated array of cipher identifiers of type cipher_type_t. The last entry is zero.

Definition at line 105 of file cipher.c.

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.

Definition at line 432 of file cipher.c.

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.

Definition at line 376 of file cipher.c.

int mbedtls_cipher_set_padding_mode	(	mbedtls_cipher_context_t *	ctx,
		mbedtls_cipher_padding_t	mode
	)

This function sets the padding mode, for cipher modes that use padding.

The default passing mode is PKCS7 padding.

Parameters:

ctx	The generic cipher context. This must be initialized and bound to a cipher information structure.
mode	The padding mode.

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

Definition at line 1028 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
	)

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.

Definition at line 278 of file cipher.c.

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

This function initializes a cipher context for use with the given cipher primitive.

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.

Definition at line 218 of file cipher.c.

int mbedtls_cipher_setup_psa	(	mbedtls_cipher_context_t *	ctx,
		const mbedtls_cipher_info_t *	cipher_info,
		size_t	taglen
	)

This function initializes a cipher context for PSA-based use with the given cipher primitive.

Note:: See MBEDTLS_USE_PSA_CRYPTO for information on PSA.

Parameters:

ctx	The context to initialize. May not be `NULL`.
cipher_info	The cipher to use.
taglen	For AEAD ciphers, the length in bytes of the authentication tag to use. Subsequent uses of mbedtls_cipher_auth_encrypt() or mbedtls_cipher_auth_decrypt() must provide the same tag length. For non-AEAD ciphers, the value must be `0`.

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.

Definition at line 247 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
	)

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.

Definition at line 504 of file cipher.c.

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

This function adds additional data for AEAD ciphers.

Currently supported with GCM and ChaCha20+Poly1305. This must be called exactly once, after mbedtls_cipher_reset().

Parameters:

ctx	The generic cipher context. This must be initialized.
ad	The additional data to use. This must be a readable buffer of at least `ad_len` Bytes.
ad_len	The length of `ad` in Bytes.

Returns:: 0 on success.; A specific error code on failure.

Definition at line 453 of file cipher.c.

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

This function writes a tag for AEAD ciphers.

Currently supported with GCM and ChaCha20+Poly1305. This must be called after mbedtls_cipher_finish().

Parameters:

ctx	The generic cipher context. This must be initialized, bound to a key, and have just completed a cipher operation through mbedtls_cipher_finish() the tag for which should be written.
tag	The buffer to write the tag to. This must be a writable buffer of at least `tag_len` Bytes.
tag_len	The length of the tag to write.

Returns:: 0 on success.; A specific error code on failure.

Definition at line 1091 of file cipher.c.

Type:	Library
Created:	17 Dec 2019
Imports:	79
Forks:	0
Commits:	2
Dependents:	2
Dependencies:	0
Followers:	1

Important changes to repositories hosted on mbed.com

cipher.c File Reference

Functions

Detailed Description

Function Documentation

Repository toolbox

Repository details

Important Information for this Arm website

Important changes to repositories hosted on mbed.com

cipher.c File Reference

Functions

Detailed Description

Function Documentation

Repository toolbox

Repository details

Important Information for this Arm website

Access Warning