Provides RFC 8439 style chacha20poly1305. More...

Detailed Description

Provides RFC 8439 style chacha20poly1305.

This module provides the chacha20poly1305 AEAD symmetric cipher following rfc 8439.

Nonces must be unique per message for a single key. They are allowed to be predictable, e.g. a message counter and are allowed to be visible during transmission.

Files
file	chacha20poly1305.h
	Chacha20poly1305 functions.

Data Structures
union	chacha20_ctx_t
	Context of a ChaCha20 multipart operation. More...

union	chacha20poly1305_ctx_t
	Chacha20poly1305 state struct. More...

Macros
#define	CHACHA20POLY1305_CONSTANT_BYTES (16U)
	Constants length in bytes.

#define	CHACHA20POLY1305_KEY_BYTES (32U)
	Key length in bytes.

#define	CHACHA20POLY1305_COUNTER_BYTES (4U)
	Counter length in bytes.

#define	CHACHA20POLY1305_NONCE_BYTES (12U)
	Nonce length in bytes.

#define	CHACHA20POLY1305_TAG_BYTES (16U)
	Tag length in bytes.

#define	CHACHA20POLY1305_BLOCK_BYTES (64U)
	Block length in bytes.

Functions
void	chacha20poly1305_encrypt (uint8_t cipher, const uint8_t msg, size_t msglen, const uint8_t aad, size_t aadlen, const uint8_t key, const uint8_t *nonce)
	Encrypt a plaintext to ciphertext and append a tag to protect the ciphertext and additional data. More...

int	chacha20poly1305_decrypt (const uint8_t cipher, size_t cipherlen, uint8_t msg, size_t msglen, const uint8_t aad, size_t aadlen, const uint8_t key, const uint8_t nonce)
	Verify the tag and decrypt a ciphertext to plaintext. More...

void	chacha20_encrypt_decrypt (const uint8_t key, const uint8_t nonce, uint32_t counter, const uint8_t input, size_t input_length, uint8_t output)
	Encrypt a plaintext to ciphertext with the ChaCha20 algorithm. More...

void	chacha20_setup (chacha20_ctx_t ctx, const uint8_t key, const uint8_t *nonce, const uint32_t counter)
	Setup a ChaCha20 encrypt or decrypt multipart operation. More...

void	chacha20_update (chacha20_ctx_t ctx, const uint8_t input, uint8_t *output)
	Update a ChaCha20 encrypt or decrypt multipart operation. More...

void	chacha20_finish (chacha20_ctx_t ctx, const uint8_t input, size_t input_length, uint8_t *output)
	Finish a ChaCha20 encrypt or decrypt multipart operation. More...

Function Documentation

◆ chacha20_encrypt_decrypt()

void chacha20_encrypt_decrypt	(	const uint8_t *	key,
		const uint8_t *	nonce,
		uint32_t	counter,
		const uint8_t *	input,
		size_t	input_length,
		uint8_t *	output
	)

Encrypt a plaintext to ciphertext with the ChaCha20 algorithm.

Parameters

[in]	key	Key to encrypt/decrypt with, must be CHACHA20POLY1305_KEY_BYTES long.
[in]	nonce	Nonce to use. Must be CHACHA20POLY1305_NONCE_BYTES long.
[in]	counter	Initial counter for the ChaCha20 operation.
[in]	input	Input for the encryption/decryption.
[in]	input_length	Length of the input byte array.
[out]	output	The resulting encrypted cipher/decrypted message.

◆ chacha20_finish()

void chacha20_finish	(	chacha20_ctx_t *	ctx,
		const uint8_t *	input,
		size_t	input_length,
		uint8_t *	output
	)

Finish a ChaCha20 encrypt or decrypt multipart operation.

Parameters

[in]	ctx	Context of the multipart ChaCha20 operation.
[in]	input	Input buffer.
[in]	input_length	Length of input buffer. Must be a less than 64B.
[out]	output	Output buffer. Must be at least length of input buffer.

◆ chacha20_setup()

void chacha20_setup	(	chacha20_ctx_t *	ctx,
		const uint8_t *	key,
		const uint8_t *	nonce,
		const uint32_t	counter
	)

Setup a ChaCha20 encrypt or decrypt multipart operation.

Parameters

[out]	ctx	Context of the multipart ChaCha20 operation.
[in]	key	Key to encrypt/decrypt with, must be CHACHA20POLY1305_KEY_BYTES long.
[in]	nonce	Nonce to use. Must be CHACHA20POLY1305_NONCE_BYTES long.
[in]	counter	Initial counter for the multipart ChaCha20 operation.

◆ chacha20_update()

void chacha20_update	(	chacha20_ctx_t *	ctx,
		const uint8_t *	input,
		uint8_t *	output
	)

Update a ChaCha20 encrypt or decrypt multipart operation.

Parameters

[in]	ctx	Context of the multipart ChaCha20 operation.
[in]	input	Input buffer containing one block of input data (64B).
[out]	output	Output buffer. Must be at least length of input buffer.

◆ chacha20poly1305_decrypt()

int chacha20poly1305_decrypt	(	const uint8_t *	cipher,
		size_t	cipherlen,
		uint8_t *	msg,
		size_t *	msglen,
		const uint8_t *	aad,
		size_t	aadlen,
		const uint8_t *	key,
		const uint8_t *	nonce
	)

Verify the tag and decrypt a ciphertext to plaintext.

It is allowed to have cipher == msg

Parameters

[in]	cipher	resulting ciphertext, is CHACHA20POLY1305_TAG_BYTES longer than the message length
[in]	cipherlen	length of the ciphertext
[out]	msg	message to encrypt
[in]	msglen	resulting length in bytes of the message
[in]	aad	additional authenticated data to verify
[in]	aadlen	length of the additional authenticated data
[in]	key	key to decrypt with, must be CHACHA20POLY1305_KEY_BYTES long
[in]	nonce	Nonce to use. Must be CHACHA20POLY1305_NONCE_BYTES long

◆ chacha20poly1305_encrypt()

void chacha20poly1305_encrypt	(	uint8_t *	cipher,
		const uint8_t *	msg,
		size_t	msglen,
		const uint8_t *	aad,
		size_t	aadlen,
		const uint8_t *	key,
		const uint8_t *	nonce
	)

Encrypt a plaintext to ciphertext and append a tag to protect the ciphertext and additional data.

It is allowed to have cipher == msg as long as there is CHACHA20POLY1305_TAG_BYTES space left to hold the authentication tag

Parameters

[out]	cipher	resulting ciphertext, is CHACHA20POLY1305_TAG_BYTES longer than the message length
[in]	msg	message to encrypt
[in]	msglen	length in bytes of the message
[in]	aad	additional authenticated data to protect
[in]	aadlen	length of the additional authenticated data
[in]	key	key to encrypt with, must be CHACHA20POLY1305_KEY_BYTES long
[in]	nonce	Nonce to use. Must be CHACHA20POLY1305_NONCE_BYTES long

Detailed Description

Files

Data Structures

Macros

Functions

Function Documentation

◆ chacha20_encrypt_decrypt()

◆ chacha20_finish()

◆ chacha20_setup()

◆ chacha20_update()

◆ chacha20poly1305_decrypt()

◆ chacha20poly1305_encrypt()