.\" $OpenBSD: EC_KEY_METHOD_new.3,v 1.4 2024/07/21 08:36:43 tb Exp $ .\" Copyright (c) 2019 Ingo Schwarze .\" .\" Permission to use, copy, modify, and distribute this software for any .\" purpose with or without fee is hereby granted, provided that the above .\" copyright notice and this permission notice appear in all copies. .\" .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. .\" .Dd $Mdocdate: July 21 2024 $ .Dt EC_KEY_METHOD_NEW 3 .Os .Sh NAME .Nm EC_KEY_METHOD_new , .Nm EC_KEY_METHOD_free , .Nm EC_KEY_METHOD_set_init , .Nm EC_KEY_METHOD_get_init , .Nm EC_KEY_METHOD_set_sign , .Nm EC_KEY_METHOD_get_sign , .Nm EC_KEY_METHOD_set_verify , .Nm EC_KEY_METHOD_get_verify , .Nm EC_KEY_METHOD_set_keygen , .Nm EC_KEY_METHOD_get_keygen , .Nm EC_KEY_METHOD_set_compute_key , .Nm EC_KEY_METHOD_get_compute_key , .Nm EC_KEY_OpenSSL , .Nm EC_KEY_set_default_method , .Nm EC_KEY_get_default_method , .Nm EC_KEY_new_method , .Nm EC_KEY_set_method , .Nm EC_KEY_get_method .Nd custom EC_KEY implementations .Sh SYNOPSIS .In openssl/ec.h .Ft EC_KEY_METHOD * .Fo EC_KEY_METHOD_new .Fa "const EC_KEY_METHOD *meth" .Fc .Ft void .Fo EC_KEY_METHOD_free .Fa "EC_KEY_METHOD *meth" .Fc .Ft void .Fo EC_KEY_METHOD_set_init .Fa "EC_KEY_METHOD *meth" .Fa "int (*init)(EC_KEY *key)" .Fa "void (*finish)(EC_KEY *key)" .Fa "int (*copy)(EC_KEY *dest, const EC_KEY *src)" .Fa "int (*set_group)(EC_KEY *key, const EC_GROUP *grp)" .Fa "int (*set_private)(EC_KEY *key, const BIGNUM *priv_key)" .Fa "int (*set_public)(EC_KEY *key, const EC_POINT *pub_key)" .Fc .Ft void .Fo EC_KEY_METHOD_get_init .Fa "const EC_KEY_METHOD *meth" .Fa "int (**pinit)(EC_KEY *key)" .Fa "void (**pfinish)(EC_KEY *key)" .Fa "int (**pcopy)(EC_KEY *dest, const EC_KEY *src)" .Fa "int (**pset_group)(EC_KEY *key, const EC_GROUP *grp)" .Fa "int (**pset_private)(EC_KEY *key, const BIGNUM *priv_key)" .Fa "int (**pset_public)(EC_KEY *key, const EC_POINT *pub_key)" .Fc .Ft void .Fo EC_KEY_METHOD_set_sign .Fa "EC_KEY_METHOD *meth" .Fa "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)" .Fa "int (*sign_setup)(EC_KEY *eckey, BN_CTX *ctx,\ BIGNUM **kinv, BIGNUM **rp)" .Fa "ECDSA_SIG *(*sign_sig)(const unsigned char *dgst, int dgstlen,\ const BIGNUM *kinv, const BIGNUM *rp, EC_KEY *eckey)" .Fc .Ft void .Fo EC_KEY_METHOD_get_sign .Fa "const EC_KEY_METHOD *meth" .Fa "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)" .Fa "int (**psign_setup)(EC_KEY *eckey, BN_CTX *ctx,\ BIGNUM **kinv, BIGNUM **rp)" .Fa "ECDSA_SIG *(**psign_sig)(const unsigned char *dgst, int dgstlen,\ const BIGNUM *kinv, const BIGNUM *rp, EC_KEY *eckey)" .Fc .Ft void .Fo EC_KEY_METHOD_set_verify .Fa "EC_KEY_METHOD *meth" .Fa "int (*verify)(int type, const unsigned char *dgst, int dgst_len,\ const unsigned char *sigbuf, int sig_len, EC_KEY *eckey)" .Fa "int (*verify_sig)(const unsigned char *dgst, int dgst_len,\ const ECDSA_SIG *sig, EC_KEY *eckey)" .Fc .Ft void .Fo EC_KEY_METHOD_get_verify .Fa "const EC_KEY_METHOD *meth" .Fa "int (**pverify)(int type, const unsigned char *dgst, int dgst_len,\ const unsigned char *sigbuf, int sig_len, EC_KEY *eckey)" .Fa "int (**pverify_sig)(const unsigned char *dgst, int dgst_len,\ const ECDSA_SIG *sig, EC_KEY *eckey)" .Fc .Ft void .Fo EC_KEY_METHOD_set_keygen .Fa "EC_KEY_METHOD *meth" .Fa "int (*keygen)(EC_KEY *key)" .Fc .Ft void .Fo EC_KEY_METHOD_get_keygen .Fa "const EC_KEY_METHOD *meth" .Fa "int (**pkeygen)(EC_KEY *key)" .Fc .Ft void .Fo EC_KEY_METHOD_set_compute_key .Fa "EC_KEY_METHOD *meth" .Fa "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))" .Fc .Ft void .Fo EC_KEY_METHOD_get_compute_key .Fa "const EC_KEY_METHOD *meth" .Fa "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))" .Fc .Ft const EC_KEY_METHOD * .Fn EC_KEY_OpenSSL void .Ft void .Fo EC_KEY_set_default_method .Fa "const EC_KEY_METHOD *meth" .Fc .Ft const EC_KEY_METHOD * .Fn EC_KEY_get_default_method void .Ft EC_KEY * .Fo EC_KEY_new_method .Fa "ENGINE *engine" .Fc .Ft int .Fo EC_KEY_set_method .Fa "EC_KEY *key" .Fa "const EC_KEY_METHOD *meth" .Fc .Ft const EC_KEY_METHOD * .Fo EC_KEY_get_method .Fa "const EC_KEY *key" .Fc .Sh DESCRIPTION An .Vt EC_KEY_METHOD object holds function pointers used for .Vt EC_KEY operations. .Pp .Fn EC_KEY_METHOD_new creates a shallow copy of .Fa meth , or an empty .Vt EC_KEY_METHOD object if .Fa meth is .Dv NULL . .Pp .Fn EC_KEY_METHOD_free frees .Fa meth . If .Fa meth is .Dv NULL or the return value of .Fn EC_KEY_OpenSSL , no action occurs. .Pp .Fn EC_KEY_METHOD_set_init and .Fn EC_KEY_METHOD_get_init set and retrieve optional callback functions called at the following places: .Pp .Bl -tag -width set_private -compact .It Fa init at the end of .Fn EC_KEY_new_method and .Fn EC_KEY_set_method .It Fa finish at the beginning of .Xr EC_KEY_free 3 , .Xr EC_KEY_copy 3 , and .Fn EC_KEY_set_method .It Fa copy at the end of .Xr EC_KEY_copy 3 .It Fa set_group at the end of .Xr EC_KEY_set_group 3 and .Xr EC_KEY_new_by_curve_name 3 .It Fa set_private at the beginning of .Xr EC_KEY_set_private_key 3 .It Fa set_public at the beginning of .Xr EC_KEY_set_public_key 3 .El .Pp If any of these callbacks returns 0, the calling function fails. By default, all these callbacks are .Dv NULL . Arguments of .Fn EC_KEY_METHOD_get_init can be set to .Dv NULL to selectively retrieve callback function pointers. .Pp .Fn EC_KEY_METHOD_set_sign and .Fn EC_KEY_METHOD_get_sign set and retrieve the functions implementing .Xr ECDSA_sign 3 and .Xr ECDSA_do_sign 3 . .Pp .Fn EC_KEY_METHOD_set_verify and .Fn EC_KEY_METHOD_get_verify set and retrieve the functions implementing .Xr ECDSA_verify 3 and .Xr ECDSA_do_verify 3 . .Pp .Fn EC_KEY_METHOD_set_keygen and .Fn EC_KEY_METHOD_get_keygen set and retrieve the function implementing .Xr EC_KEY_generate_key 3 . .Pp .Fn EC_KEY_METHOD_set_compute_key and .Fn EC_KEY_METHOD_get_compute_key set and retrieve the function implementing .Xr ECDH_compute_key 3 . .Pp .Fn EC_KEY_set_default_method chooses the .Fa meth to be used for the creation of new .Vt EC_KEY objects by future invocations of .Fn EC_KEY_new_method , or reverts to the default implementation if .Fa meth is .Dv NULL . .Pp .Fn EC_KEY_new_method creates and initializes a new .Vt EC_KEY object using the .Vt EC_KEY_METHOD set with .Fn EC_KEY_set_default_method . The .Fa ENGINE *engine argument is always ignored and passing .Dv NULL is recommended. .Pp .Fn EC_KEY_set_method dissociates the .Fa key from the .Vt ENGINE it is using, if any, and causes it to use .Fa meth in the future. .Sh RETURN VALUES .Fn EC_KEY_METHOD_new returns the newly allocated .Vt EC_KEY_METHOD object or .Dv NULL if an error occurs. .Pp .Fn EC_KEY_OpenSSL returns a static object representing the default EC_KEY implementation. .Pp .Fn EC_KEY_get_default_method returns the .Vt EC_KEY_METHOD that .Fn EC_KEY_new_method will use for the creation of new .Vt EC_KEY objects in the future. .Pp .Fn EC_KEY_new_method returns the newly allocated .Vt EC_KEY object or NULL if an error occurs. .Pp .Fn EC_KEY_set_method returns 1 for success or 0 for failure. .Pp .Fn EC_KEY_get_method returns the EC_KEY implementation used by the given .Fa key . .Sh SEE ALSO .Xr EC_KEY_new 3 , .Xr ECDSA_sign 3 .Sh HISTORY These functions first appeared in OpenSSL 1.1.0 and have been available since .Ox 6.5 .