SPP packet AES-128-GCM cipher context implementation. More...

#include "external/encryption/cipher.h"
#include "external/encryption/encryption.h"
#include <string.h>

Include dependency graph for cipher.c:

Functions
static void	s_buildNonce (const SPP_Packet_t *p_packet, spp_uint8_t p_nonce[K_SPP_CIPHER_NONCE_LEN])
	Derive the 12-byte GCM nonce from an SPP packet header.
SPP_RetVal_t	SPP_EXTERNAL_ENCRYPTION_CYPHER_encryptPacket (spp_uint8_t p_buffer, spp_uint16_t p_outSize)
	Encrypt an SPP packet buffer in-place with AES-128-GCM.

Variables
static const spp_uint8_t	s_key [K_SPP_CIPHER_KEY_LEN] = K_SPP_CIPHER_KEY

Detailed Description

SPP packet AES-128-GCM cipher context implementation.

Encrypts a raw SPP packet buffer in-place, producing the output frame: [ nonce (12 B) | ciphertext (sizeof SPP_Packet_t) | tag (16 B) ]

Definition in file cipher.c.

Function Documentation

void s_buildNonce	(	const SPP_Packet_t *	p_packet,
		spp_uint8_t	p_nonce[K_SPP_CIPHER_NONCE_LEN] )

static

Derive the 12-byte GCM nonce from an SPP packet header.

Parameters

[in]	p_packet	Packet to derive nonce from.
[out]	p_nonce	12-byte output buffer.

Definition at line 34 of file cipher.c.

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SPP_RetVal_t SPP_EXTERNAL_ENCRYPTION_CYPHER_encryptPacket	(	spp_uint8_t *	p_buffer,
		spp_uint16_t *	p_outSize )

Encrypt an SPP packet buffer in-place with AES-128-GCM.

Reads sizeof(SPP_Packet_t) bytes from p_buffer, encrypts them, and overwrites p_buffer with the output frame:

[ nonce (12 B) | ciphertext (sizeof SPP_Packet_t) | tag (16 B) ]

The nonce is derived from the packet header:

p_buffer must point to a buffer of at least K_SPP_CIPHER_FRAME_LEN bytes so the output frame fits.

Parameters

[in,out]	p_buffer	On entry: raw SPP packet bytes. On exit: encrypted frame (nonce \| ciphertext \| tag).
[out]	p_outSize	Set to K_SPP_CIPHER_FRAME_LEN on success.