gascon128.h File Reference

GASCON-128 encryption algorithm and related family members. More...

#include "aead-common.h"

Go to the source code of this file.

Data Structures
union	gascon_hash_state_t
	State information for GASCON-HASH and GASCON-XOF incremental modes. More...

Macros
#define	GASCON128_KEY_SIZE   16
	Size of the key for GASCON-128 and GASCON-128a.
#define	GASCON128_NONCE_SIZE   16
	Size of the nonce for GASCON-128 and GASCON-128a.
#define	GASCON128_TAG_SIZE   16
	Size of the authentication tag for GASCON-128 and GASCON-128a.
#define	GASCON80PQ_KEY_SIZE   20
	Size of the key for GASCON-80pq.
#define	GASCON80PQ_NONCE_SIZE   16
	Size of the nonce for GASCON-80pq.
#define	GASCON80PQ_TAG_SIZE   16
	Size of the authentication tag for GASCON-80pq.
#define	GASCON_HASH_SIZE   32
	Size of the hash output for GASCON-HASH.

Functions
int	gascon128_aead_encrypt (unsigned char *c, unsigned long long *clen, const unsigned char *m, unsigned long long mlen, const unsigned char *ad, unsigned long long adlen, const unsigned char *nsec, const unsigned char *npub, const unsigned char *k)
	Encrypts and authenticates a packet with GASCON-128. More...
int	gascon128_aead_decrypt (unsigned char *m, unsigned long long *mlen, unsigned char *nsec, const unsigned char *c, unsigned long long clen, const unsigned char *ad, unsigned long long adlen, const unsigned char *npub, const unsigned char *k)
	Decrypts and authenticates a packet with GASCON-128. More...
int	gascon128a_aead_encrypt (unsigned char *c, unsigned long long *clen, const unsigned char *m, unsigned long long mlen, const unsigned char *ad, unsigned long long adlen, const unsigned char *nsec, const unsigned char *npub, const unsigned char *k)
	Encrypts and authenticates a packet with GASCON-128a. More...
int	gascon128a_aead_decrypt (unsigned char *m, unsigned long long *mlen, unsigned char *nsec, const unsigned char *c, unsigned long long clen, const unsigned char *ad, unsigned long long adlen, const unsigned char *npub, const unsigned char *k)
	Decrypts and authenticates a packet with GASCON-128a. More...
int	gascon80pq_aead_encrypt (unsigned char *c, unsigned long long *clen, const unsigned char *m, unsigned long long mlen, const unsigned char *ad, unsigned long long adlen, const unsigned char *nsec, const unsigned char *npub, const unsigned char *k)
	Encrypts and authenticates a packet with GASCON-80pq. More...
int	gascon80pq_aead_decrypt (unsigned char *m, unsigned long long *mlen, unsigned char *nsec, const unsigned char *c, unsigned long long clen, const unsigned char *ad, unsigned long long adlen, const unsigned char *npub, const unsigned char *k)
	Decrypts and authenticates a packet with GASCON-80pq. More...
int	gascon_hash (unsigned char *out, const unsigned char *in, unsigned long long inlen)
	Hashes a block of input data with GASCON-HASH. More...
void	gascon_hash_init (gascon_hash_state_t *state)
	Initializes the state for an GASCON-HASH hashing operation. More...
void	gascon_hash_update (gascon_hash_state_t *state, const unsigned char *in, unsigned long long inlen)
	Updates an GASCON-HASH state with more input data. More...
void	gascon_hash_finalize (gascon_hash_state_t *state, unsigned char *out)
	Returns the final hash value from an GASCON-HASH hashing operation. More...
int	gascon_xof (unsigned char *out, const unsigned char *in, unsigned long long inlen)
	Hashes a block of input data with GASCON-XOF and generates a fixed-length 32 byte output. More...
void	gascon_xof_init (gascon_hash_state_t *state)
	Initializes the state for an GASCON-XOF hashing operation. More...
void	gascon_xof_absorb (gascon_hash_state_t *state, const unsigned char *in, unsigned long long inlen)
	Aborbs more input data into an GASCON-XOF state. More...
void	gascon_xof_squeeze (gascon_hash_state_t *state, unsigned char *out, unsigned long long outlen)
	Squeezes output data from an GASCON-XOF state. More...

Variables
aead_cipher_t const	gascon128_cipher
	Meta-information block for the GASCON-128 cipher.
aead_cipher_t const	gascon128a_cipher
	Meta-information block for the GASCON-128a cipher.
aead_cipher_t const	gascon80pq_cipher
	Meta-information block for the GASCON-80pq cipher.
aead_hash_algorithm_t const	gascon_hash_algorithm
	Meta-information block for the GASCON-HASH algorithm.
aead_hash_algorithm_t const	gascon_xof_algorithm
	Meta-information block for the GASCON-XOF algorithm.

Detailed Description

GASCON-128 encryption algorithm and related family members.

The GASCON family consists of several related algorithms:

• GASCON-128 with a 128-bit key, a 128-bit nonce, a 128-bit authentication tag, and a block rate of 64 bits.
• GASCON-128a with a 128-bit key, a 128-bit nonce, a 128-bit authentication tag, and a block rate of 128 bits. This is faster than GASCON-128 but may not be as secure.
• GASCON-80pq with a 160-bit key, a 128-bit nonce, a 128-bit authentication tag, and a block rate of 64 bits. This is similar to GASCON-128 but has a 160-bit key instead which may be more resistant against quantum computers.
• GASCON-HASH with a 256-bit hash output.

References: https://gascon.iaik.tugraz.at/

Function Documentation

int gascon128_aead_decrypt	(	unsigned char *	m,
		unsigned long long *	mlen,
		unsigned char *	nsec,
		const unsigned char *	c,
		unsigned long long	clen,
		const unsigned char *	ad,
		unsigned long long	adlen,
		const unsigned char *	npub,
		const unsigned char *	k
	)

Decrypts and authenticates a packet with GASCON-128.

Parameters

m	Buffer to receive the plaintext message on output.
mlen	Receives the length of the plaintext message on output.
nsec	Secret nonce - not used by this algorithm.
c	Buffer that contains the ciphertext and authentication tag to decrypt.
clen	Length of the input data in bytes, which includes the ciphertext and the 16 byte authentication tag.
ad	Buffer that contains associated data to authenticate along with the packet but which does not need to be encrypted.
adlen	Length of the associated data in bytes.
npub	Points to the public nonce for the packet which must be 16 bytes in length.
k	Points to the 16 bytes of the key to use to decrypt the packet.

Returns

0 on success, -1 if the authentication tag was incorrect, or some other negative number if there was an error in the parameters.

See Also

gascon128_aead_encrypt()

int gascon128_aead_encrypt	(	unsigned char *	c,
		unsigned long long *	clen,
		const unsigned char *	m,
		unsigned long long	mlen,
		const unsigned char *	ad,
		unsigned long long	adlen,
		const unsigned char *	nsec,
		const unsigned char *	npub,
		const unsigned char *	k
	)

Encrypts and authenticates a packet with GASCON-128.

Parameters

c	Buffer to receive the output.
clen	On exit, set to the length of the output which includes the ciphertext and the 16 byte authentication tag.
m	Buffer that contains the plaintext message to encrypt.
mlen	Length of the plaintext message in bytes.
ad	Buffer that contains associated data to authenticate along with the packet but which does not need to be encrypted.
adlen	Length of the associated data in bytes.
nsec	Secret nonce - not used by this algorithm.
npub	Points to the public nonce for the packet which must be 16 bytes in length.
k	Points to the 16 bytes of the key to use to encrypt the packet.

Returns

0 on success, or a negative value if there was an error in the parameters.

See Also

gascon128_aead_decrypt()

int gascon128a_aead_decrypt	(	unsigned char *	m,
		unsigned long long *	mlen,
		unsigned char *	nsec,
		const unsigned char *	c,
		unsigned long long	clen,
		const unsigned char *	ad,
		unsigned long long	adlen,
		const unsigned char *	npub,
		const unsigned char *	k
	)

Decrypts and authenticates a packet with GASCON-128a.

Parameters

m	Buffer to receive the plaintext message on output.
mlen	Receives the length of the plaintext message on output.
nsec	Secret nonce - not used by this algorithm.
c	Buffer that contains the ciphertext and authentication tag to decrypt.
clen	Length of the input data in bytes, which includes the ciphertext and the 16 byte authentication tag.
ad	Buffer that contains associated data to authenticate along with the packet but which does not need to be encrypted.
adlen	Length of the associated data in bytes.
npub	Points to the public nonce for the packet which must be 16 bytes in length.
k	Points to the 16 bytes of the key to use to decrypt the packet.

Returns

0 on success, -1 if the authentication tag was incorrect, or some other negative number if there was an error in the parameters.

See Also

gascon128a_aead_encrypt()

int gascon128a_aead_encrypt	(	unsigned char *	c,
		unsigned long long *	clen,
		const unsigned char *	m,
		unsigned long long	mlen,
		const unsigned char *	ad,
		unsigned long long	adlen,
		const unsigned char *	nsec,
		const unsigned char *	npub,
		const unsigned char *	k
	)

Encrypts and authenticates a packet with GASCON-128a.

Parameters

c	Buffer to receive the output.
clen	On exit, set to the length of the output which includes the ciphertext and the 16 byte authentication tag.
m	Buffer that contains the plaintext message to encrypt.
mlen	Length of the plaintext message in bytes.
ad	Buffer that contains associated data to authenticate along with the packet but which does not need to be encrypted.
adlen	Length of the associated data in bytes.
nsec	Secret nonce - not used by this algorithm.
npub	Points to the public nonce for the packet which must be 16 bytes in length.
k	Points to the 16 bytes of the key to use to encrypt the packet.

Returns

0 on success, or a negative value if there was an error in the parameters.

See Also

gascon128a_aead_decrypt()

int gascon80pq_aead_decrypt	(	unsigned char *	m,
		unsigned long long *	mlen,
		unsigned char *	nsec,
		const unsigned char *	c,
		unsigned long long	clen,
		const unsigned char *	ad,
		unsigned long long	adlen,
		const unsigned char *	npub,
		const unsigned char *	k
	)

Decrypts and authenticates a packet with GASCON-80pq.

Parameters

m	Buffer to receive the plaintext message on output.
mlen	Receives the length of the plaintext message on output.
nsec	Secret nonce - not used by this algorithm.
c	Buffer that contains the ciphertext and authentication tag to decrypt.
clen	Length of the input data in bytes, which includes the ciphertext and the 16 byte authentication tag.
ad	Buffer that contains associated data to authenticate along with the packet but which does not need to be encrypted.
adlen	Length of the associated data in bytes.
npub	Points to the public nonce for the packet which must be 16 bytes in length.
k	Points to the 20 bytes of the key to use to decrypt the packet.

Returns

0 on success, -1 if the authentication tag was incorrect, or some other negative number if there was an error in the parameters.

See Also

gascon80pq_aead_encrypt()

int gascon80pq_aead_encrypt	(	unsigned char *	c,
		unsigned long long *	clen,
		const unsigned char *	m,
		unsigned long long	mlen,
		const unsigned char *	ad,
		unsigned long long	adlen,
		const unsigned char *	nsec,
		const unsigned char *	npub,
		const unsigned char *	k
	)

Encrypts and authenticates a packet with GASCON-80pq.

Parameters

c	Buffer to receive the output.
clen	On exit, set to the length of the output which includes the ciphertext and the 16 byte authentication tag.
m	Buffer that contains the plaintext message to encrypt.
mlen	Length of the plaintext message in bytes.
ad	Buffer that contains associated data to authenticate along with the packet but which does not need to be encrypted.
adlen	Length of the associated data in bytes.
nsec	Secret nonce - not used by this algorithm.
npub	Points to the public nonce for the packet which must be 16 bytes in length.
k	Points to the 20 bytes of the key to use to encrypt the packet.

Returns

0 on success, or a negative value if there was an error in the parameters.

See Also

gascon80pq_aead_decrypt()

int gascon_hash	(	unsigned char *	out,
		const unsigned char *	in,
		unsigned long long	inlen
	)

Hashes a block of input data with GASCON-HASH.

Parameters

out	Buffer to receive the hash output which must be at least GASCON_HASH_SIZE bytes in length.
in	Points to the input data to be hashed.
inlen	Length of the input data in bytes.

Returns

Returns zero on success or -1 if there was an error in the parameters.

See Also

gascon_hash_init(), gascon_hash_absorb(), gascon_hash_squeeze()

void gascon_hash_finalize	(	gascon_hash_state_t *	state,
		unsigned char *	out
	)

Returns the final hash value from an GASCON-HASH hashing operation.

Parameters

state	Hash state to be finalized.
out	Points to the output buffer to receive the 32-byte hash value.

See Also

gascon_hash_init(), gascon_hash_update()

void gascon_hash_init

(

gascon_hash_state_t *

state

)

Initializes the state for an GASCON-HASH hashing operation.

Parameters

state

Hash state to be initialized.

See Also

gascon_hash_update(), gascon_hash_finalize(), gascon_hash()

void gascon_hash_update	(	gascon_hash_state_t *	state,
		const unsigned char *	in,
		unsigned long long	inlen
	)

Updates an GASCON-HASH state with more input data.

Parameters

state	Hash state to be updated.
in	Points to the input data to be incorporated into the state.
inlen	Length of the input data to be incorporated into the state.

See Also

gascon_hash_init(), gascon_hash_finalize()

int gascon_xof	(	unsigned char *	out,
		const unsigned char *	in,
		unsigned long long	inlen
	)

Hashes a block of input data with GASCON-XOF and generates a fixed-length 32 byte output.

Parameters

out	Buffer to receive the hash output which must be at least GASCON_HASH_SIZE bytes in length.
in	Points to the input data to be hashed.
inlen	Length of the input data in bytes.

Returns

Returns zero on success or -1 if there was an error in the parameters.

Use gascon_xof_squeeze() instead if you need variable-length XOF ouutput.

See Also

gascon_xof_init(), gascon_xof_absorb(), gascon_xof_squeeze()

void gascon_xof_absorb	(	gascon_hash_state_t *	state,
		const unsigned char *	in,
		unsigned long long	inlen
	)

Aborbs more input data into an GASCON-XOF state.

Parameters

state	Hash state to be updated.
in	Points to the input data to be absorbed into the state.
inlen	Length of the input data to be absorbed into the state.

See Also

gascon_xof_init(), gascon_xof_squeeze()

void gascon_xof_init

(

gascon_hash_state_t *

state

)

Initializes the state for an GASCON-XOF hashing operation.

Parameters

state

Hash state to be initialized.

See Also

gascon_xof_absorb(), gascon_xof_squeeze(), gascon_xof()

void gascon_xof_squeeze	(	gascon_hash_state_t *	state,
		unsigned char *	out,
		unsigned long long	outlen
	)

Squeezes output data from an GASCON-XOF state.

Parameters

state	Hash state to squeeze the output data from.
out	Points to the output buffer to receive the squeezed data.
outlen	Number of bytes of data to squeeze out of the state.

See Also

gascon_xof_init(), gascon_xof_update()