ssh_chacha20.cpp File Reference

ChaCha20 (RFC 8439) - implementation. See ssh_chacha20.h. More...

#include "network_drivers/presentation/ssh/crypto/ssh_chacha20.h"
#include "shared_primitives/crypto_opt.h"

Go to the source code of this file.

Namespaces
namespace	DETWS_CRYPTO_HOT

Macros
#define	QR(a, b, c, d)

Functions
uint32_t	DETWS_CRYPTO_HOT::rd_le32 (const uint8_t *p)
uint32_t	DETWS_CRYPTO_HOT::rotl32 (uint32_t v, int c)
void	DETWS_CRYPTO_HOT::chacha_core (const uint32_t in[16], uint8_t out[64])
void	ssh_chacha20_xor (const uint8_t key[SSH_CHACHA20_KEY_LEN], const uint8_t iv[8], uint64_t counter, const uint8_t *in, uint8_t *out, size_t len)
	XOR len bytes of in with the ChaCha20 keystream into out (OpenSSH layout).
void	ssh_chacha20_block_ietf (const uint8_t key[SSH_CHACHA20_KEY_LEN], uint32_t counter, const uint8_t nonce[12], uint8_t out[SSH_CHACHA20_BLOCK_LEN])
	One 64-byte ChaCha20 keystream block in the RFC 8439 layout (for the KAT).

Variables
const uint32_t	DETWS_CRYPTO_HOT::SIGMA0 = 0x61707865
const uint32_t	DETWS_CRYPTO_HOT::SIGMA1 = 0x3320646e
const uint32_t	DETWS_CRYPTO_HOT::SIGMA2 = 0x79622d32
const uint32_t	DETWS_CRYPTO_HOT::SIGMA3 = 0x6b206574

Detailed Description

ChaCha20 (RFC 8439) - implementation. See ssh_chacha20.h.

Definition in file ssh_chacha20.cpp.

Macro Definition Documentation

QR

#define QR	(		a,
			b,
			c,
			d
	)

Value:

    a += b;                                                                                                            \
    d ^= a;                                                                                                            \
    d = rotl32(d, 16);                                                                                                 \
    c += d;                                                                                                            \
    b ^= c;                                                                                                            \
    b = rotl32(b, 12);                                                                                                 \
    a += b;                                                                                                            \
    d ^= a;                                                                                                            \
    d = rotl32(d, 8);                                                                                                  \
    c += d;                                                                                                            \
    b ^= c;                                                                                                            \
    b = rotl32(b, 7)

Definition at line 31 of file ssh_chacha20.cpp.

Function Documentation

ssh_chacha20_xor()

void ssh_chacha20_xor	(	const uint8_t	key[SSH_CHACHA20_KEY_LEN],
		const uint8_t	iv[8],
		uint64_t	counter,
		const uint8_t *	in,
		uint8_t *	out,
		size_t	len
	)

XOR len bytes of in with the ChaCha20 keystream into out (OpenSSH layout).

Parameters

key	32-byte key.
iv	8-byte nonce (OpenSSH uses the packet sequence number, big-endian).
counter	initial 64-bit block counter (0 for the Poly1305-key / length blocks, 1 for the packet payload); it increments per 64-byte block.
in	plaintext (or ciphertext when decrypting); may be nullptr to emit raw keystream.
out	output buffer (len bytes); may alias in.

Definition at line 79 of file ssh_chacha20.cpp.

Referenced by ssh_chachapoly_decrypt(), ssh_chachapoly_encrypt(), and ssh_chachapoly_get_length().

ssh_chacha20_block_ietf()

void ssh_chacha20_block_ietf	(	const uint8_t	key[SSH_CHACHA20_KEY_LEN],
		uint32_t	counter,
		const uint8_t	nonce[12],
		uint8_t	out[SSH_CHACHA20_BLOCK_LEN]
	)

One 64-byte ChaCha20 keystream block in the RFC 8439 layout (for the KAT).

Parameters

key	32-byte key.
counter	32-bit block counter (word 12).
nonce	12-byte nonce (words 13-15).
out	64-byte keystream block.

Definition at line 106 of file ssh_chacha20.cpp.