es256_pk_new
, es256_pk_free
,
es256_pk_from_EC_KEY
,
es256_pk_from_ptr
,
es256_pk_to_EVP_PKEY
—
FIDO 2 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_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_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
() and
es256_pk_from_ptr
() functions return
FIDO_OK
on success. On error, a different error code
defined in <fido/err.h>
is
returned.