ssh_chachapoly.cpp File Reference

chach.nosp@m.a20-.nosp@m.poly1.nosp@m.305@.nosp@m.opens.nosp@m.sh.c.nosp@m.om - implementation. See ssh_chachapoly.h. More...

#include "network_drivers/presentation/ssh/crypto/ssh_chachapoly.h"
#include "network_drivers/presentation/ssh/crypto/ssh_chacha20.h"
#include "network_drivers/presentation/ssh/crypto/ssh_poly1305.h"
#include <string.h>

Go to the source code of this file.

Functions
uint32_t	ssh_chachapoly_get_length (const uint8_t key[SSH_CHACHAPOLY_KEY_LEN], uint32_t seqnr, const uint8_t enc_len[SSH_CHACHAPOLY_AAD_LEN])
	Decrypt just the 4-byte length field to learn the packet length before reading the body.
void	ssh_chachapoly_encrypt (const uint8_t key[SSH_CHACHAPOLY_KEY_LEN], uint32_t seqnr, uint8_t *dest, const uint8_t *src, uint32_t payload_len)
	Encrypt+authenticate one packet.
bool	ssh_chachapoly_decrypt (const uint8_t key[SSH_CHACHAPOLY_KEY_LEN], uint32_t seqnr, uint8_t *dest, const uint8_t *src, uint32_t payload_len)
	Verify+decrypt one packet.

Detailed Description

chach.nosp@m.a20-.nosp@m.poly1.nosp@m.305@.nosp@m.opens.nosp@m.sh.c.nosp@m.om - implementation. See ssh_chachapoly.h.

Definition in file ssh_chachapoly.cpp.

Function Documentation

ssh_chachapoly_get_length()

uint32_t ssh_chachapoly_get_length	(	const uint8_t	key[SSH_CHACHAPOLY_KEY_LEN],
		uint32_t	seqnr,
		const uint8_t	enc_len[SSH_CHACHAPOLY_AAD_LEN]
	)

Decrypt just the 4-byte length field to learn the packet length before reading the body.

Returns

the SSH packet_length (bytes of the packet after the length field, excluding the tag).

Definition at line 40 of file ssh_chachapoly.cpp.

References ssh_chacha20_xor().

Referenced by ssh_pkt_recv().

ssh_chachapoly_encrypt()

void ssh_chachapoly_encrypt	(	const uint8_t	key[SSH_CHACHAPOLY_KEY_LEN],
		uint32_t	seqnr,
		uint8_t *	dest,
		const uint8_t *	src,
		uint32_t	payload_len
	)

Encrypt+authenticate one packet.

Parameters

src	plaintext: 4-byte packet length (big-endian) || payload_len payload bytes.
dest	output: encrypted length (4) || encrypted payload (payload_len) || tag (16). May alias src. dest must hold 4 + payload_len + 16 bytes.

Definition at line 50 of file ssh_chachapoly.cpp.

References ssh_chacha20_xor(), and ssh_poly1305().

Referenced by ssh_pkt_send().

ssh_chachapoly_decrypt()

bool ssh_chachapoly_decrypt	(	const uint8_t	key[SSH_CHACHAPOLY_KEY_LEN],
		uint32_t	seqnr,
		uint8_t *	dest,
		const uint8_t *	src,
		uint32_t	payload_len
	)

Verify+decrypt one packet.

Parameters

src	ciphertext: encrypted length (4) || encrypted payload (payload_len) || tag (16).
dest	output: plaintext length (4) || plaintext payload (payload_len). May alias src.

Returns

true if the Poly1305 tag verified; false (and no usable plaintext) otherwise.

Definition at line 62 of file ssh_chachapoly.cpp.

References ssh_chacha20_xor(), and ssh_poly1305().

Referenced by ssh_pkt_recv().