NAME¶

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

SYNOPSIS¶

#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);

DESCRIPTION¶

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 oflibfido2is an auxiliary API with routines to convert between the differentECDSA public key types used inlibfido2andOpenSSL.

Inlibfido2,ES256 public keys are abstracted by thees256_pk_ttype.

Thees256_pk_new()function returns a pointer to a newly allocated, emptyes256_pk_ttype.If memory cannot be allocated, NULL is returned.

Thees256_pk_free()function releases the memory backing*pkp,where*pkpmust have been previously allocated byes256_pk_new().On return,*pkpis set to NULL.Eitherpkpor*pkpmay be NULL, in which casees256_pk_free()is a NOP.

Thees256_pk_from_EC_KEY()function fillspkwith the contents ofec.No references toecare kept.

Thees256_pk_from_EVP_PKEY()function fillspkwith the contents ofpkey.No references topkeyare kept.

Thees256_pk_from_ptr()function fillspkwith the contents ofptr,whereptrpoints tolenbytes.Theptrpointer may point to an uncompressed point, or to theconcatenation of the x and y coordinates.No references toptrare kept.

Thees256_pk_to_EVP_PKEY()function convertspkto a newly allocatedEVP_PKEYtype 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.

RETURN VALUES¶

Thees256_pk_from_EC_KEY(),es256_pk_from_EVP_PKEY(),andes256_pk_from_ptr()functions returnFIDO_OKon success.On error, a different error code defined in<fido/err.h>is returned.

SEE ALSO¶

eddsa_pk_new(3),es384_pk_new(3),fido_assert_verify(3),fido_cred_pubkey_ptr(3),rs256_pk_new(3)