es256_pk_new,
es256_pk_free,
es256_pk_from_EC_KEY,
es256_pk_from_EVP_PKEY,
es256_pk_from_ptr,
es256_pk_to_EVP_PKEY —
FIDO2 COSE ES256 API
#include
<openssl/ec.h>
#include
<fido/es256.h>
es256_pk_t *
es256_pk_new(
void);
void
es256_pk_free(
es256_pk_t
**pkp);
int
es256_pk_from_EC_KEY(
es256_pk_t
*pk,
const
EC_KEY *ec);
int
es256_pk_from_EVP_PKEY(
es256_pk_t
*pk,
const
EVP_PKEY *pkey);
int
es256_pk_from_ptr(
es256_pk_t
*pk,
const void
*ptr,
size_t
len);
EVP_PKEY *
es256_pk_to_EVP_PKEY(
const
es256_pk_t *pk);
ES256 is the name given in the CBOR Object Signing and Encryption (COSE) RFC to
ECDSA over P-256 with SHA-256. The COSE ES256 API of
libfido2 is an auxiliary API with routines to
convert between the different ECDSA public key types used in
libfido2 and
OpenSSL.
In
libfido2, ES256 public keys are abstracted by
the
es256_pk_t type.
The
es256_pk_new() function returns a pointer
to a newly allocated, empty
es256_pk_t type.
If memory cannot be allocated, NULL is returned.
The
es256_pk_free() function releases the
memory backing
*pkp, where
*pkp must have been previously allocated by
es256_pk_new(). On return,
*pkp is set to NULL. Either
pkp or
*pkp
may be NULL, in which case
es256_pk_free()
is a NOP.
The
es256_pk_from_EC_KEY() function fills
pk with the contents of
ec. No references to
ec are kept.
The
es256_pk_from_EVP_PKEY() function fills
pk with the contents of
pkey. No references to
pkey are kept.
The
es256_pk_from_ptr() function fills
pk with the contents of
ptr, where
ptr points to
len bytes. The
ptr pointer may point to an uncompressed
point, or to the concatenation of the x and y coordinates. No references to
ptr are kept.
The
es256_pk_to_EVP_PKEY() function converts
pk to a newly allocated
EVP_PKEY type with a reference count of 1. No
internal references to the returned pointer are kept. If an error occurs,
es256_pk_to_EVP_PKEY() returns NULL.
The
es256_pk_from_EC_KEY(),
es256_pk_from_EVP_PKEY(), and
es256_pk_from_ptr() functions return
FIDO_OK on success. On error, a different
error code defined in
<fido/err.h>
is returned.
eddsa_pk_new(3),
es384_pk_new(3),
fido_assert_verify(3),
fido_cred_pubkey_ptr(3),
rs256_pk_new(3)