ffdhe.h File Reference

Finite Field Diffie-Hellman Ephemeral key exchange. More...

#include <stddef.h>
#include <byteswap.h>
#include <ipxe/bigint.h>
#include <ipxe/crypto.h>

Go to the source code of this file.

Data Structures
struct	ffdhe_group
	A finite field DHE group. More...

Macros
#define	FFDHE_GROUP(_name, _exchange, _constant, _bits, _expbits, _lsb)
	Define a finite field DHE group.

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
	FILE_SECBOOT (PERMITTED)
int	ffdhe_share (struct exchange_algorithm *exchange, const void *private, void *public)
	Share public key.
int	ffdhe_agree (struct exchange_algorithm *exchange, const void *private, const void *partner, void *shared)
	Agree shared secret.
int	ffdhe_has_params (struct exchange_algorithm *exchange, const void *modulus, size_t len, const void *generator, size_t generator_len)
	Check group parameters.
static int	is_ffdhe (struct exchange_algorithm *exchange)
	Check if key exchange algorithm is a finite field DHE group.

Variables
struct exchange_algorithm	ffdhe2048_algorithm
struct exchange_algorithm	ffdhe3072_algorithm
struct exchange_algorithm	ffdhe4096_algorithm
struct exchange_algorithm	modp2048_algorithm
struct exchange_algorithm	modp3072_algorithm
struct exchange_algorithm	modp4096_algorithm

Detailed Description

Finite Field Diffie-Hellman Ephemeral key exchange.

Definition in file ffdhe.h.

Macro Definition Documentation

FFDHE_GROUP

#define FFDHE_GROUP	(		_name,
			_exchange,
			_constant,
			_bits,
			_expbits,
			_lsb )

Value:

static struct ffdhe_group _name ## _group = {                     \
        .name = #_name,                                           \
        .constant = (_constant),                                  \
        .len = ( _bits / 8 ),                                     \
        .size = bigint_required_size ( _bits / 8 ),               \
        .explen = ( ( _expbits + 7 ) / 8 ),                       \
        .expsize = bigint_required_size ( ( _expbits + 7 ) / 8 ), \
        .lsb32 = cpu_to_be32 ( _lsb ),                            \
};                                                                \
struct exchange_algorithm _exchange = {                           \
        .name = #_name,                                           \
        .privsize = ( ( _expbits + 7 ) / 8 ),                     \
        .pubsize = ( _bits / 8 ),                                 \
        .sharedsize = ( _bits / 8 ),                              \
        .share = ffdhe_share,                                     \
        .agree = ffdhe_agree,                                     \
        .priv = &_name ## _group,                                 \
}

Define a finite field DHE group.

Definition at line 58 of file ffdhe.h.

#define FFDHE_GROUP( _name, _exchange, _constant, _bits, _expbits, _lsb ) \
        static struct ffdhe_group _name ## _group = {                     \
                .name = #_name,                                           \
                .constant = (_constant),                                  \
                .len = ( _bits / 8 ),                                     \
                .size = bigint_required_size ( _bits / 8 ),               \
                .explen = ( ( _expbits + 7 ) / 8 ),                       \
                .expsize = bigint_required_size ( ( _expbits + 7 ) / 8 ), \
                .lsb32 = cpu_to_be32 ( _lsb ),                            \
        };                                                                \
        struct exchange_algorithm _exchange = {                           \
                .name = #_name,                                           \
                .privsize = ( ( _expbits + 7 ) / 8 ),                     \
                .pubsize = ( _bits / 8 ),                                 \
                .sharedsize = ( _bits / 8 ),                              \
                .share = ffdhe_share,                                     \
                .agree = ffdhe_agree,                                     \
                .priv = &_name ## _group,                                 \
        }

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

FILE_SECBOOT()

FILE_SECBOOT

(

PERMITTED

)

ffdhe_share()

int ffdhe_share ( struct exchange_algorithm * exchange, const void * private, void * public )

extern

Share public key.

Parameters

exchange	Key exchange algorithm
private	Private key
public	Public key to fill in

Return values

rc	Return status code

Definition at line 275 of file ffdhe.c.

                                 {
        struct ffdhe_group *group = exchange->priv;
 
        return ffdhe ( group, NULL, private, public );
}

References ffdhe(), group, NULL, and exchange_algorithm::priv.

Referenced by is_ffdhe().

ffdhe_agree()

int ffdhe_agree ( struct exchange_algorithm * exchange, const void * private, const void * partner, void * shared )

extern

Agree shared secret.

Parameters

exchange	Key exchange algorithm
private	Private key
partner	Partner public key
shared	Shared secret to fill in

Return values

rc	Return status code

Definition at line 291 of file ffdhe.c.

                                                      {
        struct ffdhe_group *group = exchange->priv;
 
        return ffdhe ( group, partner, private, shared );
}

References ffdhe(), group, partner, and exchange_algorithm::priv.

ffdhe_has_params()

int ffdhe_has_params ( struct exchange_algorithm * exchange, const void * dh_p, size_t dh_p_len, const void * dh_g, size_t dh_g_len )

extern

Check group parameters.

Parameters

exchange	Key exchange algorithm
dh_p	Prime modulus
dh_p_len	Length of prime modulus
dh_g	Generator
dh_g_len	Length of generator

Return values

match

Field parameters are correct for this group

Leading zeros in the modulus and generator will be tolerated.

Definition at line 310 of file ffdhe.c.

                                                           {
        struct ffdhe_group *group = exchange->priv;
        const ffdhe_modulus_t ( group->len ) *modulus;
        const uint8_t *generator;
 
        /* Sanity check */
        assert ( is_ffdhe ( exchange ) );
 
        /* Strip leading zeros from modulus and check length */
        while ( dh_p_len && ( ! *( ( uint8_t * ) dh_p ) ) ) {
                dh_p++;
                dh_p_len--;
        }
        if ( dh_p_len != sizeof ( *modulus ) )
                return 0;
        modulus = dh_p;
 
        /* Strip leading zeros from generator and check length */
        while ( dh_g_len && ( ! *( ( uint8_t * ) dh_g ) ) ) {
                dh_g++;
                dh_g_len--;
        }
        if ( dh_g_len != sizeof ( *generator ) )
                return 0;
        generator = dh_g;
 
        /* Check values */
        return ( ( modulus->high == ~( ( uint64_t ) 0 ) ) &&
                 ( memcmp ( modulus->constant, group->constant,
                            sizeof ( modulus->constant ) ) == 0 ) &&
                 ( modulus->lsb32 == group->lsb32 ) &&
                 ( modulus->low == ~( ( uint64_t ) 0 ) ) &&
                 ( *generator == 2 ) );
}

References assert, ffdhe_modulus_t, group, is_ffdhe(), memcmp(), and exchange_algorithm::priv.

Referenced by tls_find_param_group().

is_ffdhe()

int is_ffdhe ( struct exchange_algorithm * exchange )

inlinestatic

Check if key exchange algorithm is a finite field DHE group.

Parameters

exchange

Key exchange algorithm

Return values

is_ffdhe

Key exchange algorithm is a finite field DHE group

Definition at line 52 of file ffdhe.h.

                                                 {
 
        return ( exchange->share == ffdhe_share );
}

References ffdhe_share(), and exchange_algorithm::share.

Referenced by ffdhe_has_params(), and tls_find_param_group().

Variable Documentation

ffdhe2048_algorithm

struct exchange_algorithm ffdhe2048_algorithm

extern

Referenced by __tls_named_group(), EXCHANGE_TEST(), EXCHANGE_TEST(), EXCHANGE_TEST(), EXCHANGE_TEST(), and FFDHE_GROUP().

ffdhe3072_algorithm

struct exchange_algorithm ffdhe3072_algorithm

extern

Referenced by __tls_named_group(), EXCHANGE_TEST(), and FFDHE_GROUP().

ffdhe4096_algorithm

struct exchange_algorithm ffdhe4096_algorithm

extern

Referenced by __tls_named_group(), EXCHANGE_TEST(), and FFDHE_GROUP().

modp2048_algorithm

struct exchange_algorithm modp2048_algorithm

extern

Referenced by EXCHANGE_TEST(), and FFDHE_GROUP().

modp3072_algorithm

struct exchange_algorithm modp3072_algorithm

extern

Referenced by EXCHANGE_TEST(), and FFDHE_GROUP().

modp4096_algorithm

struct exchange_algorithm modp4096_algorithm

extern

Referenced by EXCHANGE_TEST(), and FFDHE_GROUP().