Detailed Description

Accelerated AES-CCM AEAD cipher using the CRYPTOACC or SE peripheral.

Data Structures
struct	mbedtls_ccm_context
	The CCM context-type definition. The CCM context is passed to the APIs called.

Functions
void	mbedtls_ccm_init (mbedtls_ccm_context *ctx)
	This function initializes the specified CCM context, to make references valid, and prepare the context for mbedtls_ccm_setkey() or mbedtls_ccm_free().

int	mbedtls_ccm_setkey (mbedtls_ccm_context ctx, `mbedtls_cipher_id_t` cipher, const unsigned char key, unsigned int keybits)
	This function initializes the CCM context set in the `ctx` parameter and sets the encryption key.

void	mbedtls_ccm_free (mbedtls_ccm_context *ctx)
	This function releases and clears the specified CCM context and underlying cipher sub-context.

int	mbedtls_ccm_encrypt_and_tag (mbedtls_ccm_context ctx, size_t length, const unsigned char iv, size_t iv_len, const unsigned char add, size_t add_len, const unsigned char input, unsigned char output, unsigned char tag, size_t tag_len)
	This function encrypts a buffer using CCM.

int	mbedtls_ccm_auth_decrypt (mbedtls_ccm_context ctx, size_t length, const unsigned char iv, size_t iv_len, const unsigned char add, size_t add_len, const unsigned char input, unsigned char output, const unsigned char tag, size_t tag_len)
	This function performs a CCM authenticated decryption of a buffer.

Function Documentation

This function performs a CCM authenticated decryption of a buffer.

Parameters

`ctx`	The CCM context to use for decryption.
`length`	The length of the input data in Bytes.
`iv`	Initialization vector.
`iv_len`	The length of the IV in Bytes: 7, 8, 9, 10, 11, 12, or 13.
`add`	The additional data field.
`add_len`	The length of additional data in Bytes. Must be less than 2^16 - 2^8.
`input`	The buffer holding the input data.
`output`	The buffer holding the output data. Must be at least `length` Bytes wide.
`tag`	The buffer holding the tag.
`tag_len`	The length of the tag in Bytes. 4, 6, 8, 10, 12, 14 or 16.

Returns: 0 if successful and authenticated, or MBEDTLS_ERR_CCM_AUTH_FAILED if the tag does not match.

int mbedtls_ccm_encrypt_and_tag	(	mbedtls_ccm_context *	`ctx,`
		size_t	`length,`
		const unsigned char *	`iv,`
		size_t	`iv_len,`
		const unsigned char *	`add,`
		size_t	`add_len,`
		const unsigned char *	`input,`
		unsigned char *	`output,`
		unsigned char *	`tag,`
		size_t	`tag_len`
	)

This function encrypts a buffer using CCM.

Parameters

`ctx`	The CCM context to use for encryption.
`length`	The length of the input data in Bytes.
`iv`	Initialization vector (nonce).
`iv_len`	The length of the IV in Bytes: 7, 8, 9, 10, 11, 12, or 13.
`add`	The additional data field.
`add_len`	The length of additional data in Bytes. Must be less than 2^16 - 2^8.
`input`	The buffer holding the input data.
`output`	The buffer holding the output data. Must be at least `length` Bytes wide.
`tag`	The buffer holding the tag.
`tag_len`	The length of the tag to generate in Bytes: 4, 6, 8, 10, 12, 14 or 16.

Note: The tag is written to a separate buffer. To concatenate the tag with the output, as done in RFC-3610: Counter with CBC-MAC (CCM), use tag = output + length, and make sure that the output buffer is at least length + tag_len wide.

void mbedtls_ccm_free ( mbedtls_ccm_context * ctx )

This function releases and clears the specified CCM context and underlying cipher sub-context.

Parameters

ctx The CCM context to clear.

void mbedtls_ccm_init ( mbedtls_ccm_context * ctx )

This function initializes the specified CCM context, to make references valid, and prepare the context for mbedtls_ccm_setkey() or mbedtls_ccm_free().

Parameters

ctx The CCM context to initialize.

This function initializes the CCM context set in the ctx parameter and sets the encryption key.

Parameters

`ctx`	The CCM context to initialize.
`cipher`	The 128-bit block cipher to use.
`key`	The encryption key.
`keybits`	The key size in bits. This must be acceptable by the cipher.