NAME

EC_KEY_METHOD_new, EC_KEY_METHOD_free, EC_KEY_METHOD_set_init, EC_KEY_METHOD_get_init, EC_KEY_METHOD_set_sign, EC_KEY_METHOD_get_sign, EC_KEY_METHOD_set_verify, EC_KEY_METHOD_get_verify, EC_KEY_METHOD_set_keygen, EC_KEY_METHOD_get_keygen, EC_KEY_METHOD_set_compute_key, EC_KEY_METHOD_get_compute_key, EC_KEY_OpenSSL, EC_KEY_set_default_method, EC_KEY_get_default_method, EC_KEY_new_method, EC_KEY_set_method, EC_KEY_get_method — custom EC_KEY implementations

SYNOPSIS

#include <openssl/ec.h> EC_KEY_METHOD *
EC_KEY_METHOD_new(const EC_KEY_METHOD *meth); void
EC_KEY_METHOD_free(EC_KEY_METHOD *meth); void
EC_KEY_METHOD_set_init(EC_KEY_METHOD *meth, int (*init)(EC_KEY *key), void (*finish)(EC_KEY *key), int (*copy)(EC_KEY *dest, const EC_KEY *src), int (*set_group)(EC_KEY *key, const EC_GROUP *grp), int (*set_private)(EC_KEY *key, const BIGNUM *priv_key), int (*set_public)(EC_KEY *key, const EC_POINT *pub_key)); void
EC_KEY_METHOD_get_init(const EC_KEY_METHOD *meth, int (**pinit)(EC_KEY *key), void (**pfinish)(EC_KEY *key), int (**pcopy)(EC_KEY *dest, const EC_KEY *src), int (**pset_group)(EC_KEY *key, const EC_GROUP *grp), int (**pset_private)(EC_KEY *key, const BIGNUM *priv_key), int (**pset_public)(EC_KEY *key, const EC_POINT *pub_key)); void
EC_KEY_METHOD_set_sign(EC_KEY_METHOD *meth, int (*sign)(int type, const unsigned char *dgst, int dgstlen, unsigned char *sig, unsigned int *siglen, const BIGNUM *kinv, const BIGNUM *r, EC_KEY *eckey), int (*sign_setup)(EC_KEY *eckey, BN_CTX *ctx, BIGNUM **kinv, BIGNUM **rp), ECDSA_SIG *(*sign_sig)(const unsigned char *dgst, int dgstlen, const BIGNUM *kinv, const BIGNUM *rp, EC_KEY *eckey)); void
EC_KEY_METHOD_get_sign(const EC_KEY_METHOD *meth, int (**psign)(int type, const unsigned char *dgst, int dgstlen, unsigned char *sig, unsigned int *siglen, const BIGNUM *kinv, const BIGNUM *r, EC_KEY *eckey), int (**psign_setup)(EC_KEY *eckey, BN_CTX *ctx, BIGNUM **kinv, BIGNUM **rp), ECDSA_SIG *(**psign_sig)(const unsigned char *dgst, int dgstlen, const BIGNUM *kinv, const BIGNUM *rp, EC_KEY *eckey)); void
EC_KEY_METHOD_set_verify(EC_KEY_METHOD *meth, int (*verify)(int type, const unsigned char *dgst, int dgst_len, const unsigned char *sigbuf, int sig_len, EC_KEY *eckey), int (*verify_sig)(const unsigned char *dgst, int dgst_len, const ECDSA_SIG *sig, EC_KEY *eckey)); void
EC_KEY_METHOD_get_verify(const EC_KEY_METHOD *meth, int (**pverify)(int type, const unsigned char *dgst, int dgst_len, const unsigned char *sigbuf, int sig_len, EC_KEY *eckey), int (**pverify_sig)(const unsigned char *dgst, int dgst_len, const ECDSA_SIG *sig, EC_KEY *eckey)); void
EC_KEY_METHOD_set_keygen(EC_KEY_METHOD *meth, int (*keygen)(EC_KEY *key)); void
EC_KEY_METHOD_get_keygen(const EC_KEY_METHOD *meth, int (**pkeygen)(EC_KEY *key)); void
EC_KEY_METHOD_set_compute_key(EC_KEY_METHOD *meth, int (*ckey)(void *out, size_t outlen, const EC_POINT *pub_key, EC_KEY *ecdh, void *(*KDF) (const void *in, size_t inlen, void *out, size_t *outlen))); void
EC_KEY_METHOD_get_compute_key(const EC_KEY_METHOD *meth, int (**pck)(void *out, size_t outlen, const EC_POINT *pub_key, EC_KEY *ecdh, void *(*KDF) (const void *in, size_t inlen, void *out, size_t *outlen))); const EC_KEY_METHOD *
EC_KEY_OpenSSL(void); void
EC_KEY_set_default_method(const EC_KEY_METHOD *meth); const EC_KEY_METHOD *
EC_KEY_get_default_method(void); EC_KEY *
EC_KEY_new_method(ENGINE *engine); int
EC_KEY_set_method(EC_KEY *key, const EC_KEY_METHOD *meth); const EC_KEY_METHOD *
EC_KEY_get_method(const EC_KEY *key);

DESCRIPTION

An EC_KEY_METHOD object holds function pointers used for EC_KEY operations. EC_KEY_METHOD_new() creates a shallow copy of meth, or an empty EC_KEY_METHOD object if meth is NULL. EC_KEY_METHOD_free() frees meth. If meth is NULL or the return value of EC_KEY_OpenSSL(), no action occurs. EC_KEY_METHOD_set_init() and EC_KEY_METHOD_get_init() set and retrieve optional callback functions called at the following places:

init

at the end of EC_KEY_new_method() and EC_KEY_set_method()

finish

at the beginning of EC_KEY_free(3), EC_KEY_copy(3), and EC_KEY_set_method()

copy

at the end of EC_KEY_copy(3)

set_group

at the end of EC_KEY_set_group(3) and EC_KEY_new_by_curve_name(3)

set_private

at the beginning of EC_KEY_set_private_key(3)

set_public

at the beginning of EC_KEY_set_public_key(3)

If any of these callbacks returns 0, the calling function fails. By default, all these callbacks are NULL. Arguments of EC_KEY_METHOD_get_init() can be set to NULL to selectively retrieve callback function pointers. EC_KEY_METHOD_set_sign() and EC_KEY_METHOD_get_sign() set and retrieve the functions implementing ECDSA_sign(3) and ECDSA_do_sign(3). EC_KEY_METHOD_set_verify() and EC_KEY_METHOD_get_verify() set and retrieve the functions implementing ECDSA_verify(3) and ECDSA_do_verify(3). EC_KEY_METHOD_set_keygen() and EC_KEY_METHOD_get_keygen() set and retrieve the function implementing EC_KEY_generate_key(3). EC_KEY_METHOD_set_compute_key() and EC_KEY_METHOD_get_compute_key() set and retrieve the function implementing ECDH_compute_key(3). EC_KEY_set_default_method() chooses the meth to be used for the creation of new EC_KEY objects by future invocations of EC_KEY_new_method(), or reverts to the default implementation if meth is NULL. EC_KEY_new_method() creates and initializes a new EC_KEY object using the EC_KEY_METHOD set with EC_KEY_set_default_method(). The ENGINE *engine argument is always ignored and passing NULL is recommended. EC_KEY_set_method() dissociates the key from the ENGINE it is using, if any, and causes it to use meth in the future.

RETURN VALUES

EC_KEY_METHOD_new() returns the newly allocated EC_KEY_METHOD object or NULL if an error occurs. EC_KEY_OpenSSL() returns a static object representing the default EC_KEY implementation. EC_KEY_get_default_method() returns the EC_KEY_METHOD that EC_KEY_new_method() will use for the creation of new EC_KEY objects in the future. EC_KEY_new_method() returns the newly allocated EC_KEY object or NULL if an error occurs. EC_KEY_set_method() returns 1 for success or 0 for failure. EC_KEY_get_method() returns the EC_KEY implementation used by the given key.

SEE ALSO

EC_KEY_new(3), ECDSA_sign(3)

HISTORY

These functions first appeared in OpenSSL 1.1.0 and have been available since OpenBSD 6.5.