cipher.h File Reference

This file contains an abstraction interface for use with the cipher primitives provided by the library. It provides a common interface to all of the available cipher operations. More...

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

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Data Structures
struct	mbedtls_cipher_info_t
struct	mbedtls_cipher_context_t

Macros
#define	MBEDTLS_CIPHER_MODE_AEAD
#define	MBEDTLS_CIPHER_MODE_WITH_PADDING
#define	MBEDTLS_CIPHER_MODE_STREAM
#define	MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE   -0x6080
#define	MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA   -0x6100
#define	MBEDTLS_ERR_CIPHER_ALLOC_FAILED   -0x6180
#define	MBEDTLS_ERR_CIPHER_INVALID_PADDING   -0x6200
#define	MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED   -0x6280
#define	MBEDTLS_ERR_CIPHER_AUTH_FAILED   -0x6300
#define	MBEDTLS_ERR_CIPHER_INVALID_CONTEXT   -0x6380
#define	MBEDTLS_CIPHER_VARIABLE_IV_LEN   0x01
#define	MBEDTLS_CIPHER_VARIABLE_KEY_LEN   0x02
#define	MBEDTLS_MAX_IV_LENGTH   16
#define	MBEDTLS_MAX_BLOCK_LENGTH   16
#define	MBEDTLS_MAX_KEY_LENGTH   64

Typedefs
typedef struct mbedtls_cipher_base_t	mbedtls_cipher_base_t
typedef struct mbedtls_cmac_context_t	mbedtls_cmac_context_t
typedef struct mbedtls_cipher_info_t	mbedtls_cipher_info_t
typedef struct mbedtls_cipher_context_t	mbedtls_cipher_context_t

Enumerations
enum	mbedtls_cipher_id_t {   MBEDTLS_CIPHER_ID_NONE = 0, MBEDTLS_CIPHER_ID_NULL, MBEDTLS_CIPHER_ID_AES, MBEDTLS_CIPHER_ID_DES,   MBEDTLS_CIPHER_ID_3DES, MBEDTLS_CIPHER_ID_CAMELLIA, MBEDTLS_CIPHER_ID_ARIA, MBEDTLS_CIPHER_ID_CHACHA20 }
	Supported cipher types. More...
enum	mbedtls_cipher_type_t {   MBEDTLS_CIPHER_NONE = 0, MBEDTLS_CIPHER_NULL, MBEDTLS_CIPHER_AES_128_ECB, MBEDTLS_CIPHER_AES_192_ECB,   MBEDTLS_CIPHER_AES_256_ECB, MBEDTLS_CIPHER_AES_128_CBC, MBEDTLS_CIPHER_AES_192_CBC, MBEDTLS_CIPHER_AES_256_CBC,   MBEDTLS_CIPHER_AES_128_CFB128, MBEDTLS_CIPHER_AES_192_CFB128, MBEDTLS_CIPHER_AES_256_CFB128, MBEDTLS_CIPHER_AES_128_CTR,   MBEDTLS_CIPHER_AES_192_CTR, MBEDTLS_CIPHER_AES_256_CTR, MBEDTLS_CIPHER_AES_128_GCM, MBEDTLS_CIPHER_AES_192_GCM,   MBEDTLS_CIPHER_AES_256_GCM, MBEDTLS_CIPHER_CAMELLIA_128_ECB, MBEDTLS_CIPHER_CAMELLIA_192_ECB, MBEDTLS_CIPHER_CAMELLIA_256_ECB,   MBEDTLS_CIPHER_CAMELLIA_128_CBC, MBEDTLS_CIPHER_CAMELLIA_192_CBC, MBEDTLS_CIPHER_CAMELLIA_256_CBC, MBEDTLS_CIPHER_CAMELLIA_128_CFB128,   MBEDTLS_CIPHER_CAMELLIA_192_CFB128, MBEDTLS_CIPHER_CAMELLIA_256_CFB128, MBEDTLS_CIPHER_CAMELLIA_128_CTR, MBEDTLS_CIPHER_CAMELLIA_192_CTR,   MBEDTLS_CIPHER_CAMELLIA_256_CTR, MBEDTLS_CIPHER_CAMELLIA_128_GCM, MBEDTLS_CIPHER_CAMELLIA_192_GCM, MBEDTLS_CIPHER_CAMELLIA_256_GCM,   MBEDTLS_CIPHER_DES_ECB, MBEDTLS_CIPHER_DES_CBC, MBEDTLS_CIPHER_DES_EDE_ECB, MBEDTLS_CIPHER_DES_EDE_CBC,   MBEDTLS_CIPHER_DES_EDE3_ECB, MBEDTLS_CIPHER_DES_EDE3_CBC, MBEDTLS_CIPHER_AES_128_CCM, MBEDTLS_CIPHER_AES_192_CCM,   MBEDTLS_CIPHER_AES_256_CCM, MBEDTLS_CIPHER_AES_128_CCM_STAR_NO_TAG, MBEDTLS_CIPHER_AES_192_CCM_STAR_NO_TAG, MBEDTLS_CIPHER_AES_256_CCM_STAR_NO_TAG,   MBEDTLS_CIPHER_CAMELLIA_128_CCM, MBEDTLS_CIPHER_CAMELLIA_192_CCM, MBEDTLS_CIPHER_CAMELLIA_256_CCM, MBEDTLS_CIPHER_CAMELLIA_128_CCM_STAR_NO_TAG,   MBEDTLS_CIPHER_CAMELLIA_192_CCM_STAR_NO_TAG, MBEDTLS_CIPHER_CAMELLIA_256_CCM_STAR_NO_TAG, MBEDTLS_CIPHER_ARIA_128_ECB, MBEDTLS_CIPHER_ARIA_192_ECB,   MBEDTLS_CIPHER_ARIA_256_ECB, MBEDTLS_CIPHER_ARIA_128_CBC, MBEDTLS_CIPHER_ARIA_192_CBC, MBEDTLS_CIPHER_ARIA_256_CBC,   MBEDTLS_CIPHER_ARIA_128_CFB128, MBEDTLS_CIPHER_ARIA_192_CFB128, MBEDTLS_CIPHER_ARIA_256_CFB128, MBEDTLS_CIPHER_ARIA_128_CTR,   MBEDTLS_CIPHER_ARIA_192_CTR, MBEDTLS_CIPHER_ARIA_256_CTR, MBEDTLS_CIPHER_ARIA_128_GCM, MBEDTLS_CIPHER_ARIA_192_GCM,   MBEDTLS_CIPHER_ARIA_256_GCM, MBEDTLS_CIPHER_ARIA_128_CCM, MBEDTLS_CIPHER_ARIA_192_CCM, MBEDTLS_CIPHER_ARIA_256_CCM,   MBEDTLS_CIPHER_ARIA_128_CCM_STAR_NO_TAG, MBEDTLS_CIPHER_ARIA_192_CCM_STAR_NO_TAG, MBEDTLS_CIPHER_ARIA_256_CCM_STAR_NO_TAG, MBEDTLS_CIPHER_AES_128_OFB,   MBEDTLS_CIPHER_AES_192_OFB, MBEDTLS_CIPHER_AES_256_OFB, MBEDTLS_CIPHER_AES_128_XTS, MBEDTLS_CIPHER_AES_256_XTS,   MBEDTLS_CIPHER_CHACHA20, MBEDTLS_CIPHER_CHACHA20_POLY1305, MBEDTLS_CIPHER_AES_128_KW, MBEDTLS_CIPHER_AES_192_KW,   MBEDTLS_CIPHER_AES_256_KW, MBEDTLS_CIPHER_AES_128_KWP, MBEDTLS_CIPHER_AES_192_KWP, MBEDTLS_CIPHER_AES_256_KWP }
	Supported {cipher type, cipher mode} pairs. More...
enum	mbedtls_cipher_mode_t {   MBEDTLS_MODE_NONE = 0, MBEDTLS_MODE_ECB, MBEDTLS_MODE_CBC, MBEDTLS_MODE_CFB,   MBEDTLS_MODE_OFB, MBEDTLS_MODE_CTR, MBEDTLS_MODE_GCM, MBEDTLS_MODE_STREAM,   MBEDTLS_MODE_CCM, MBEDTLS_MODE_CCM_STAR_NO_TAG, MBEDTLS_MODE_XTS, MBEDTLS_MODE_CHACHAPOLY,   MBEDTLS_MODE_KW, MBEDTLS_MODE_KWP }
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_operation_t { MBEDTLS_OPERATION_NONE = -1, MBEDTLS_DECRYPT = 0, MBEDTLS_ENCRYPT }
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)
	This function retrieves the list of ciphers supported by the generic cipher module. 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_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_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...
static mbedtls_cipher_type_t	mbedtls_cipher_info_get_type (const mbedtls_cipher_info_t *info)
	Retrieve the identifier for a cipher info structure. More...
static mbedtls_cipher_mode_t	mbedtls_cipher_info_get_mode (const mbedtls_cipher_info_t *info)
	Retrieve the operation mode for a cipher info structure. More...
static size_t	mbedtls_cipher_info_get_key_bitlen (const mbedtls_cipher_info_t *info)
	Retrieve the key size for a cipher info structure. More...
static const char *	mbedtls_cipher_info_get_name (const mbedtls_cipher_info_t *info)
	Retrieve the human-readable name for a cipher info structure. More...
static size_t	mbedtls_cipher_info_get_iv_size (const mbedtls_cipher_info_t *info)
	This function returns the size of the IV or nonce for the cipher info structure, in bytes. More...
static size_t	mbedtls_cipher_info_get_block_size (const mbedtls_cipher_info_t *info)
	This function returns the block size of the given cipher info structure in bytes. More...
static int	mbedtls_cipher_info_has_variable_key_bitlen (const mbedtls_cipher_info_t *info)
	This function returns a non-zero value if the key length for the given cipher is variable. More...
static int	mbedtls_cipher_info_has_variable_iv_size (const mbedtls_cipher_info_t *info)
	This function returns a non-zero value if the IV size for the given cipher is variable. 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 prepares a cipher context for use with the given cipher primitive. More...
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. More...
static unsigned int	mbedtls_cipher_get_block_size (const mbedtls_cipher_context_t *ctx)
	This function returns the block size of the given cipher in bytes. More...
static mbedtls_cipher_mode_t	mbedtls_cipher_get_cipher_mode (const mbedtls_cipher_context_t *ctx)
	This function returns the mode of operation for the cipher. For example, MBEDTLS_MODE_CBC. More...
static int	mbedtls_cipher_get_iv_size (const mbedtls_cipher_context_t *ctx)
	This function returns the size of the IV or nonce of the cipher, in Bytes. More...
static mbedtls_cipher_type_t	mbedtls_cipher_get_type (const mbedtls_cipher_context_t *ctx)
	This function returns the type of the given cipher. More...
static const char *	mbedtls_cipher_get_name (const mbedtls_cipher_context_t *ctx)
	This function returns the name of the given cipher as a string. More...
static int	mbedtls_cipher_get_key_bitlen (const mbedtls_cipher_context_t *ctx)
	This function returns the key length of the cipher. More...
static mbedtls_operation_t	mbedtls_cipher_get_operation (const mbedtls_cipher_context_t *ctx)
	This function returns the operation of the given cipher. 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_padding_mode (mbedtls_cipher_context_t *ctx, mbedtls_cipher_padding_t mode)
	This function sets the padding mode, for cipher modes that use padding. 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_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. 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_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(). More...
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(). 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_ext (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 output_len, size_t *olen, size_t tag_len)
	The authenticated encryption (AEAD/NIST_KW) function. More...
int	mbedtls_cipher_auth_decrypt_ext (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 output_len, size_t *olen, size_t tag_len)
	The authenticated encryption (AEAD/NIST_KW) function. More...

Detailed Description

This file contains an abstraction interface for use with the cipher primitives provided by the library. It provides a common interface to all of the available cipher operations.

Author

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

Definition in file cipher.h.

Macro Definition Documentation

#define MBEDTLS_CIPHER_MODE_AEAD

Definition at line 37 of file cipher.h.

#define MBEDTLS_CIPHER_MODE_STREAM

Definition at line 46 of file cipher.h.

#define MBEDTLS_CIPHER_MODE_WITH_PADDING

Definition at line 41 of file cipher.h.

#define MBEDTLS_CIPHER_VARIABLE_IV_LEN   0x01

Cipher accepts IVs of variable length.

Definition at line 69 of file cipher.h.

Referenced by mbedtls_cipher_info_has_variable_iv_size().

#define MBEDTLS_CIPHER_VARIABLE_KEY_LEN   0x02

Cipher accepts keys of variable length.

Definition at line 70 of file cipher.h.

Referenced by mbedtls_cipher_info_has_variable_key_bitlen().

#define MBEDTLS_ERR_CIPHER_ALLOC_FAILED   -0x6180

Failed to allocate memory.

Definition at line 59 of file cipher.h.

#define MBEDTLS_ERR_CIPHER_AUTH_FAILED   -0x6300

Authentication failed (for AEAD modes).

Definition at line 65 of file cipher.h.

#define MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA   -0x6100

Bad input parameters.

Definition at line 57 of file cipher.h.

#define MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE   -0x6080

The selected feature is not available.

Definition at line 55 of file cipher.h.

#define MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED   -0x6280

Decryption of block requires a full block.

Definition at line 63 of file cipher.h.

#define MBEDTLS_ERR_CIPHER_INVALID_CONTEXT   -0x6380

The context is invalid. For example, because it was freed.

Definition at line 67 of file cipher.h.

#define MBEDTLS_ERR_CIPHER_INVALID_PADDING   -0x6200

Input data contains invalid padding and is rejected.

Definition at line 61 of file cipher.h.

#define MBEDTLS_MAX_BLOCK_LENGTH   16

Maximum block size of any cipher, in Bytes.

Definition at line 243 of file cipher.h.

#define MBEDTLS_MAX_IV_LENGTH   16

Maximum length of any IV, in Bytes.

Definition at line 237 of file cipher.h.

#define MBEDTLS_MAX_KEY_LENGTH   64

Maximum key length, in Bytes.

Definition at line 253 of file cipher.h.

Typedef Documentation

typedef struct mbedtls_cipher_base_t mbedtls_cipher_base_t

Base cipher information (opaque struct).

Definition at line 261 of file cipher.h.

typedef struct mbedtls_cipher_context_t mbedtls_cipher_context_t

Generic cipher context.

typedef struct mbedtls_cipher_info_t mbedtls_cipher_info_t

Cipher information. Allows calling cipher functions in a generic way.

Note

The library does not support custom cipher info structures, only built-in structures returned by the functions mbedtls_cipher_info_from_string(), mbedtls_cipher_info_from_type(), mbedtls_cipher_info_from_values(), mbedtls_cipher_info_from_psa().

typedef struct mbedtls_cmac_context_t mbedtls_cmac_context_t

CMAC context (opaque struct).

Definition at line 266 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 222 of file cipher.h.

enum mbedtls_cipher_id_t

Supported cipher types.

Warning

DES is considered weak cipher and its use constitutes a security risk. Arm recommends considering stronger ciphers instead.

Enumerator
MBEDTLS_CIPHER_ID_NONE	Placeholder to mark the end of cipher ID lists.
MBEDTLS_CIPHER_ID_NULL	The identity cipher, treated as a stream cipher.
MBEDTLS_CIPHER_ID_AES	The AES cipher.
MBEDTLS_CIPHER_ID_DES	The DES cipher.
MBEDTLS_CIPHER_ID_3DES	The Triple DES cipher.
MBEDTLS_CIPHER_ID_CAMELLIA	The Camellia cipher.
MBEDTLS_CIPHER_ID_ARIA	The Aria cipher.
MBEDTLS_CIPHER_ID_CHACHA20	The ChaCha20 cipher.

Definition at line 83 of file cipher.h.

enum mbedtls_cipher_mode_t

Supported cipher modes.

Enumerator
MBEDTLS_MODE_NONE	None.
MBEDTLS_MODE_ECB	The ECB cipher mode.
MBEDTLS_MODE_CBC	The CBC cipher mode.
MBEDTLS_MODE_CFB	The CFB cipher mode.
MBEDTLS_MODE_OFB	The OFB cipher mode.
MBEDTLS_MODE_CTR	The CTR cipher mode.
MBEDTLS_MODE_GCM	The GCM cipher mode.
MBEDTLS_MODE_STREAM	The stream cipher mode.
MBEDTLS_MODE_CCM	The CCM cipher mode.
MBEDTLS_MODE_CCM_STAR_NO_TAG	The CCM*-no-tag cipher mode.
MBEDTLS_MODE_XTS	The XTS cipher mode.
MBEDTLS_MODE_CHACHAPOLY	The ChaCha-Poly cipher mode.
MBEDTLS_MODE_KW	The SP800-38F KW mode
MBEDTLS_MODE_KWP	The SP800-38F KWP mode

Definition at line 189 of file cipher.h.

enum mbedtls_cipher_padding_t

Supported cipher padding types.

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 207 of file cipher.h.

enum mbedtls_cipher_type_t

Supported {cipher type, cipher mode} pairs.

Warning

DES is considered weak cipher and its use constitutes a security risk. Arm recommends considering stronger ciphers instead.

Enumerator
MBEDTLS_CIPHER_NONE	Placeholder to mark the end of cipher-pair lists.
MBEDTLS_CIPHER_NULL	The identity stream cipher.
MBEDTLS_CIPHER_AES_128_ECB	AES cipher with 128-bit ECB mode.
MBEDTLS_CIPHER_AES_192_ECB	AES cipher with 192-bit ECB mode.
MBEDTLS_CIPHER_AES_256_ECB	AES cipher with 256-bit ECB mode.
MBEDTLS_CIPHER_AES_128_CBC	AES cipher with 128-bit CBC mode.
MBEDTLS_CIPHER_AES_192_CBC	AES cipher with 192-bit CBC mode.
MBEDTLS_CIPHER_AES_256_CBC	AES cipher with 256-bit CBC mode.
MBEDTLS_CIPHER_AES_128_CFB128	AES cipher with 128-bit CFB128 mode.
MBEDTLS_CIPHER_AES_192_CFB128	AES cipher with 192-bit CFB128 mode.
MBEDTLS_CIPHER_AES_256_CFB128	AES cipher with 256-bit CFB128 mode.
MBEDTLS_CIPHER_AES_128_CTR	AES cipher with 128-bit CTR mode.
MBEDTLS_CIPHER_AES_192_CTR	AES cipher with 192-bit CTR mode.
MBEDTLS_CIPHER_AES_256_CTR	AES cipher with 256-bit CTR mode.
MBEDTLS_CIPHER_AES_128_GCM	AES cipher with 128-bit GCM mode.
MBEDTLS_CIPHER_AES_192_GCM	AES cipher with 192-bit GCM mode.
MBEDTLS_CIPHER_AES_256_GCM	AES cipher with 256-bit GCM mode.
MBEDTLS_CIPHER_CAMELLIA_128_ECB	Camellia cipher with 128-bit ECB mode.
MBEDTLS_CIPHER_CAMELLIA_192_ECB	Camellia cipher with 192-bit ECB mode.
MBEDTLS_CIPHER_CAMELLIA_256_ECB	Camellia cipher with 256-bit ECB mode.
MBEDTLS_CIPHER_CAMELLIA_128_CBC	Camellia cipher with 128-bit CBC mode.
MBEDTLS_CIPHER_CAMELLIA_192_CBC	Camellia cipher with 192-bit CBC mode.
MBEDTLS_CIPHER_CAMELLIA_256_CBC	Camellia cipher with 256-bit CBC mode.
MBEDTLS_CIPHER_CAMELLIA_128_CFB128	Camellia cipher with 128-bit CFB128 mode.
MBEDTLS_CIPHER_CAMELLIA_192_CFB128	Camellia cipher with 192-bit CFB128 mode.
MBEDTLS_CIPHER_CAMELLIA_256_CFB128	Camellia cipher with 256-bit CFB128 mode.
MBEDTLS_CIPHER_CAMELLIA_128_CTR	Camellia cipher with 128-bit CTR mode.
MBEDTLS_CIPHER_CAMELLIA_192_CTR	Camellia cipher with 192-bit CTR mode.
MBEDTLS_CIPHER_CAMELLIA_256_CTR	Camellia cipher with 256-bit CTR mode.
MBEDTLS_CIPHER_CAMELLIA_128_GCM	Camellia cipher with 128-bit GCM mode.
MBEDTLS_CIPHER_CAMELLIA_192_GCM	Camellia cipher with 192-bit GCM mode.
MBEDTLS_CIPHER_CAMELLIA_256_GCM	Camellia cipher with 256-bit GCM mode.
MBEDTLS_CIPHER_DES_ECB	DES cipher with ECB mode.
MBEDTLS_CIPHER_DES_CBC	DES cipher with CBC mode.
MBEDTLS_CIPHER_DES_EDE_ECB	DES cipher with EDE ECB mode.
MBEDTLS_CIPHER_DES_EDE_CBC	DES cipher with EDE CBC mode.
MBEDTLS_CIPHER_DES_EDE3_ECB	DES cipher with EDE3 ECB mode.
MBEDTLS_CIPHER_DES_EDE3_CBC	DES cipher with EDE3 CBC mode.
MBEDTLS_CIPHER_AES_128_CCM	AES cipher with 128-bit CCM mode.
MBEDTLS_CIPHER_AES_192_CCM	AES cipher with 192-bit CCM mode.
MBEDTLS_CIPHER_AES_256_CCM	AES cipher with 256-bit CCM mode.
MBEDTLS_CIPHER_AES_128_CCM_STAR_NO_TAG	AES cipher with 128-bit CCM_STAR_NO_TAG mode.
MBEDTLS_CIPHER_AES_192_CCM_STAR_NO_TAG	AES cipher with 192-bit CCM_STAR_NO_TAG mode.
MBEDTLS_CIPHER_AES_256_CCM_STAR_NO_TAG	AES cipher with 256-bit CCM_STAR_NO_TAG mode.
MBEDTLS_CIPHER_CAMELLIA_128_CCM	Camellia cipher with 128-bit CCM mode.
MBEDTLS_CIPHER_CAMELLIA_192_CCM	Camellia cipher with 192-bit CCM mode.
MBEDTLS_CIPHER_CAMELLIA_256_CCM	Camellia cipher with 256-bit CCM mode.
MBEDTLS_CIPHER_CAMELLIA_128_CCM_STAR_NO_TAG	Camellia cipher with 128-bit CCM_STAR_NO_TAG mode.
MBEDTLS_CIPHER_CAMELLIA_192_CCM_STAR_NO_TAG	Camellia cipher with 192-bit CCM_STAR_NO_TAG mode.
MBEDTLS_CIPHER_CAMELLIA_256_CCM_STAR_NO_TAG	Camellia cipher with 256-bit CCM_STAR_NO_TAG mode.
MBEDTLS_CIPHER_ARIA_128_ECB	Aria cipher with 128-bit key and ECB mode.
MBEDTLS_CIPHER_ARIA_192_ECB	Aria cipher with 192-bit key and ECB mode.
MBEDTLS_CIPHER_ARIA_256_ECB	Aria cipher with 256-bit key and ECB mode.
MBEDTLS_CIPHER_ARIA_128_CBC	Aria cipher with 128-bit key and CBC mode.
MBEDTLS_CIPHER_ARIA_192_CBC	Aria cipher with 192-bit key and CBC mode.
MBEDTLS_CIPHER_ARIA_256_CBC	Aria cipher with 256-bit key and CBC mode.
MBEDTLS_CIPHER_ARIA_128_CFB128	Aria cipher with 128-bit key and CFB-128 mode.
MBEDTLS_CIPHER_ARIA_192_CFB128	Aria cipher with 192-bit key and CFB-128 mode.
MBEDTLS_CIPHER_ARIA_256_CFB128	Aria cipher with 256-bit key and CFB-128 mode.
MBEDTLS_CIPHER_ARIA_128_CTR	Aria cipher with 128-bit key and CTR mode.
MBEDTLS_CIPHER_ARIA_192_CTR	Aria cipher with 192-bit key and CTR mode.
MBEDTLS_CIPHER_ARIA_256_CTR	Aria cipher with 256-bit key and CTR mode.
MBEDTLS_CIPHER_ARIA_128_GCM	Aria cipher with 128-bit key and GCM mode.
MBEDTLS_CIPHER_ARIA_192_GCM	Aria cipher with 192-bit key and GCM mode.
MBEDTLS_CIPHER_ARIA_256_GCM	Aria cipher with 256-bit key and GCM mode.
MBEDTLS_CIPHER_ARIA_128_CCM	Aria cipher with 128-bit key and CCM mode.
MBEDTLS_CIPHER_ARIA_192_CCM	Aria cipher with 192-bit key and CCM mode.
MBEDTLS_CIPHER_ARIA_256_CCM	Aria cipher with 256-bit key and CCM mode.
MBEDTLS_CIPHER_ARIA_128_CCM_STAR_NO_TAG	Aria cipher with 128-bit key and CCM_STAR_NO_TAG mode.
MBEDTLS_CIPHER_ARIA_192_CCM_STAR_NO_TAG	Aria cipher with 192-bit key and CCM_STAR_NO_TAG mode.
MBEDTLS_CIPHER_ARIA_256_CCM_STAR_NO_TAG	Aria cipher with 256-bit key and CCM_STAR_NO_TAG mode.
MBEDTLS_CIPHER_AES_128_OFB	AES 128-bit cipher in OFB mode.
MBEDTLS_CIPHER_AES_192_OFB	AES 192-bit cipher in OFB mode.
MBEDTLS_CIPHER_AES_256_OFB	AES 256-bit cipher in OFB mode.
MBEDTLS_CIPHER_AES_128_XTS	AES 128-bit cipher in XTS block mode.
MBEDTLS_CIPHER_AES_256_XTS	AES 256-bit cipher in XTS block mode.
MBEDTLS_CIPHER_CHACHA20	ChaCha20 stream cipher.
MBEDTLS_CIPHER_CHACHA20_POLY1305	ChaCha20-Poly1305 AEAD cipher.
MBEDTLS_CIPHER_AES_128_KW	AES cipher with 128-bit NIST KW mode.
MBEDTLS_CIPHER_AES_192_KW	AES cipher with 192-bit NIST KW mode.
MBEDTLS_CIPHER_AES_256_KW	AES cipher with 256-bit NIST KW mode.
MBEDTLS_CIPHER_AES_128_KWP	AES cipher with 128-bit NIST KWP mode.
MBEDTLS_CIPHER_AES_192_KWP	AES cipher with 192-bit NIST KWP mode.
MBEDTLS_CIPHER_AES_256_KWP	AES cipher with 256-bit NIST KWP mode.

Definition at line 101 of file cipher.h.

enum mbedtls_operation_t

Type of operation.

Enumerator
MBEDTLS_OPERATION_NONE
MBEDTLS_DECRYPT
MBEDTLS_ENCRYPT

Definition at line 216 of file cipher.h.

Function Documentation

int mbedtls_cipher_auth_decrypt_ext	(	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	output_len,
		size_t *	olen,
		size_t	tag_len
	)

The authenticated encryption (AEAD/NIST_KW) 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.

For AEAD modes, the tag must be appended to the ciphertext, as recommended by RFC 5116. (NIST_KW doesn't have a separate tag.)

Parameters

ctx	The generic cipher context. This must be initialized and bound to a key, with an AEAD algorithm or NIST_KW.
iv	The nonce to use. This must be a readable buffer of at least iv_len Bytes and may be NULL if iv_len is 0.
iv_len	The length of the nonce. For AEAD ciphers, this must satisfy the constraints imposed by the cipher used. For NIST_KW, this must be 0.
ad	The additional data to authenticate. This must be a readable buffer of at least ad_len Bytes, and may be NULL is ad_len is 0.
ad_len	The length of ad. For NIST_KW, this must be 0.
input	The buffer holding the input data. This must be a readable buffer of at least ilen Bytes, and may be NULL if ilen is 0.
ilen	The length of the input data. For AEAD ciphers this must be at least tag_len. For NIST_KW this must be at least 8.
output	The buffer for the output data. This must be a writable buffer of at least output_len Bytes, and may be NULL if output_len is 0.
output_len	The length of the output buffer in Bytes. For AEAD ciphers, this must be at least ilen - tag_len. For NIST_KW, this must be at least ilen - 8.
olen	This will be filled with the actual number of Bytes written to the output buffer. This must point to a writable object of type size_t.
tag_len	The actual length of the authentication tag. For AEAD ciphers, this must match the constraints imposed by the cipher used, and in particular must not be 0. For NIST_KW, this must be 0.

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.

int mbedtls_cipher_auth_encrypt_ext	(	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	output_len,
		size_t *	olen,
		size_t	tag_len
	)

The authenticated encryption (AEAD/NIST_KW) function.

Note

For AEAD modes, the tag will be appended to the ciphertext, as recommended by RFC 5116. (NIST_KW doesn't have a separate tag.)

Parameters

ctx	The generic cipher context. This must be initialized and bound to a key, with an AEAD algorithm or NIST_KW.
iv	The nonce to use. This must be a readable buffer of at least iv_len Bytes and may be NULL if iv_len is 0.
iv_len	The length of the nonce. For AEAD ciphers, this must satisfy the constraints imposed by the cipher used. For NIST_KW, this must be 0.
ad	The additional data to authenticate. This must be a readable buffer of at least ad_len Bytes, and may be NULL is ad_len is 0.
ad_len	The length of ad. For NIST_KW, this must be 0.
input	The buffer holding the input data. This must be a readable buffer of at least ilen Bytes, and may be NULL if ilen is 0.
ilen	The length of the input data.
output	The buffer for the output data. This must be a writable buffer of at least output_len Bytes, and must not be NULL.
output_len	The length of the output buffer in Bytes. For AEAD ciphers, this must be at least ilen + tag_len. For NIST_KW, this must be at least ilen + 8 (rounded up to a multiple of 8 if KWP is used); ilen + 15 is always a safe value.
olen	This will be filled with the actual number of Bytes written to the output buffer. This must point to a writable object of type size_t.
tag_len	The desired length of the authentication tag. For AEAD ciphers, this must match the constraints imposed by the cipher used, and in particular must not be 0. For NIST_KW, this must be 0.

Returns

0 on success.

MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on parameter-verification failure.

A cipher-specific error code on failure.

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.

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.

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.

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.

static unsigned int mbedtls_cipher_get_block_size ( const mbedtls_cipher_context_t *  ctx )

inlinestatic

This function returns the block size of the given cipher in bytes.

Parameters

ctx	The context of the cipher.

Returns

The block size of the underlying cipher.

1 if the cipher is a stream cipher.

0 if ctx has not been initialized.

Definition at line 669 of file cipher.h.

References MBEDTLS_INTERNAL_VALIDATE_RET.

static mbedtls_cipher_mode_t mbedtls_cipher_get_cipher_mode ( const mbedtls_cipher_context_t *  ctx )

inlinestatic

This function returns the mode of operation for the cipher. For example, MBEDTLS_MODE_CBC.

Parameters

ctx	The context of the cipher. This must be initialized.

Returns

The mode of operation.

MBEDTLS_MODE_NONE if ctx has not been initialized.

Definition at line 688 of file cipher.h.

References MBEDTLS_INTERNAL_VALIDATE_RET, and MBEDTLS_MODE_NONE.

static int mbedtls_cipher_get_iv_size ( const mbedtls_cipher_context_t *  ctx )

inlinestatic

This function returns the size of the IV or nonce of the cipher, in Bytes.

Parameters

ctx	The context of the cipher. This must be initialized.

Returns

The recommended IV size if no IV has been set.

0 for ciphers not using an IV or a nonce.

The actual size if an IV has been set.

Definition at line 708 of file cipher.h.

References MBEDTLS_INTERNAL_VALIDATE_RET.

static int mbedtls_cipher_get_key_bitlen ( const mbedtls_cipher_context_t *  ctx )

inlinestatic

This function returns the key length of the cipher.

Parameters

ctx	The context of the cipher. This must be initialized.

Returns

The key length of the cipher in bits.

MBEDTLS_KEY_LENGTH_NONE if ctx has not been initialized.

Definition at line 768 of file cipher.h.

References MBEDTLS_INTERNAL_VALIDATE_RET, and MBEDTLS_KEY_LENGTH_NONE.

static const char* mbedtls_cipher_get_name ( const mbedtls_cipher_context_t *  ctx )

inlinestatic

This function returns the name of the given cipher as a string.

Parameters

ctx	The context of the cipher. This must be initialized.

Returns

The name of the cipher.

NULL if ctx has not been not initialized.

Definition at line 749 of file cipher.h.

References MBEDTLS_INTERNAL_VALIDATE_RET.

static mbedtls_operation_t mbedtls_cipher_get_operation ( const mbedtls_cipher_context_t *  ctx )

inlinestatic

This function returns the operation of the given cipher.

Parameters

ctx	The context of the cipher. This must be initialized.

Returns

The type of operation: MBEDTLS_ENCRYPT or MBEDTLS_DECRYPT.

MBEDTLS_OPERATION_NONE if ctx has not been initialized.

Definition at line 787 of file cipher.h.

References MBEDTLS_INTERNAL_VALIDATE_RET, and MBEDTLS_OPERATION_NONE.

static mbedtls_cipher_type_t mbedtls_cipher_get_type ( const mbedtls_cipher_context_t *  ctx )

inlinestatic

This function returns the type of the given cipher.

Parameters

ctx	The context of the cipher. This must be initialized.

Returns

The type of the cipher.

MBEDTLS_CIPHER_NONE if ctx has not been initialized.

Definition at line 729 of file cipher.h.

References MBEDTLS_CIPHER_NONE, and MBEDTLS_INTERNAL_VALIDATE_RET.

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.

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.

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.

static size_t mbedtls_cipher_info_get_block_size ( const mbedtls_cipher_info_t *  info )

inlinestatic

This function returns the block size of the given cipher info structure in bytes.

Parameters

info	The cipher info structure. This may be NULL.

Returns

The block size of the cipher.

1 if the cipher is a stream cipher.

0 if info is NULL.

Definition at line 539 of file cipher.h.

static size_t mbedtls_cipher_info_get_iv_size ( const mbedtls_cipher_info_t *  info )

inlinestatic

This function returns the size of the IV or nonce for the cipher info structure, in bytes.

Parameters

info	The cipher info structure. This may be NULL.

Returns

The recommended IV size.

0 for ciphers not using an IV or a nonce.

0 if info is NULL.

Definition at line 520 of file cipher.h.

static size_t mbedtls_cipher_info_get_key_bitlen ( const mbedtls_cipher_info_t *  info )

inlinestatic

Retrieve the key size for a cipher info structure.

Parameters

[in]

info

The cipher info structure to query. This may be NULL.

Returns

The key length in bits. For variable-sized ciphers, this is the default length. For DES, this includes the parity bits.

0 if info is NULL.

Definition at line 481 of file cipher.h.

static mbedtls_cipher_mode_t mbedtls_cipher_info_get_mode ( const mbedtls_cipher_info_t *  info )

inlinestatic

Retrieve the operation mode for a cipher info structure.

Parameters

[in]

info

The cipher info structure to query. This may be NULL.

Returns

The cipher mode (MBEDTLS_MODE_xxx).

MBEDTLS_MODE_NONE if info is NULL.

Definition at line 461 of file cipher.h.

References MBEDTLS_MODE_NONE.

static const char* mbedtls_cipher_info_get_name ( const mbedtls_cipher_info_t *  info )

inlinestatic

Retrieve the human-readable name for a cipher info structure.

Parameters

[in]

info

The cipher info structure to query. This may be NULL.

Returns

The cipher name, which is a human readable string, with static storage duration.

NULL if info is NULL.

Definition at line 501 of file cipher.h.

static mbedtls_cipher_type_t mbedtls_cipher_info_get_type ( const mbedtls_cipher_info_t *  info )

inlinestatic

Retrieve the identifier for a cipher info structure.

Parameters

[in]

info

The cipher info structure to query. This may be NULL.

Returns

The full cipher identifier (MBEDTLS_CIPHER_xxx).

MBEDTLS_CIPHER_NONE if info is NULL.

Definition at line 443 of file cipher.h.

References MBEDTLS_CIPHER_NONE.

static int mbedtls_cipher_info_has_variable_iv_size ( const mbedtls_cipher_info_t *  info )

inlinestatic

This function returns a non-zero value if the IV size for the given cipher is variable.

Parameters

info	The cipher info structure. This may be NULL.

Returns

Non-zero if the IV size is variable, 0 otherwise.

0 if the given pointer is NULL.

Definition at line 575 of file cipher.h.

References MBEDTLS_CIPHER_VARIABLE_IV_LEN.

static int mbedtls_cipher_info_has_variable_key_bitlen ( const mbedtls_cipher_info_t *  info )

inlinestatic

This function returns a non-zero value if the key length for the given cipher is variable.

Parameters

info	The cipher info structure. This may be NULL.

Returns

Non-zero if the key length is variable, 0 otherwise.

0 if the given pointer is NULL.

Definition at line 557 of file cipher.h.

References MBEDTLS_CIPHER_VARIABLE_KEY_LEN.

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.

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.

int mbedtls_cipher_reset

(

mbedtls_cipher_context_t *

ctx

)

This function resets the cipher state.

Note

With non-AEAD ciphers, the order of calls for each message is as follows:

1. mbedtls_cipher_set_iv() if the mode uses an IV/nonce.
2. mbedtls_cipher_reset()
3. mbedtls_cipher_update() one or more times
4. mbedtls_cipher_finish()

This sequence can be repeated to encrypt or decrypt multiple messages with the same key.

With AEAD ciphers, the order of calls for each message is as follows:

1. mbedtls_cipher_set_iv() if the mode uses an IV/nonce.
2. mbedtls_cipher_reset()
3. mbedtls_cipher_update_ad()
4. mbedtls_cipher_update() one or more times
5. mbedtls_cipher_finish()
6. mbedtls_cipher_check_tag() (for decryption) or mbedtls_cipher_write_tag() (for encryption).

This sequence can be repeated to encrypt or decrypt multiple messages with the same key.

Parameters

ctx	The generic cipher context. This must be bound to a key.

Returns

0 on success.

MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on parameter-verification failure.

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.

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.

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.

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

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

Note

After calling this function, you should call mbedtls_cipher_setkey() and, if the mode uses padding, mbedtls_cipher_set_padding_mode(), then for each message to encrypt or decrypt with this key, either:

• mbedtls_cipher_crypt() for one-shot processing with non-AEAD modes;
• mbedtls_cipher_auth_encrypt_ext() or mbedtls_cipher_auth_decrypt_ext() for one-shot processing with AEAD modes or NIST_KW;
• for multi-part processing, see the documentation of mbedtls_cipher_reset().

Parameters

ctx	The context to prepare. This must be initialized by a call to mbedtls_cipher_init() first.
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.

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_ext() or mbedtls_cipher_auth_decrypt_ext() 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.

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.

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.

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.

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.

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.