NAME

       eddsa_pk_new,  eddsa_pk_free,  eddsa_pk_from_EVP_PKEY,  eddsa_pk_from_ptr,  eddsa_pk_to_EVP_PKEY — FIDO 2
       COSE EDDSA API

SYNOPSIS

       #include <openssl/evp.h>
       #include <fido/eddsa.h>

       eddsa_pk_t *
       eddsa_pk_new(void);

       void
       eddsa_pk_free(eddsa_pk_t **pkp);

       int
       eddsa_pk_from_EVP_PKEY(eddsa_pk_t *pk, const EVP_PKEY *pkey);

       int
       eddsa_pk_from_ptr(eddsa_pk_t *pk, const void *ptr, size_t len);

       EVP_PKEY *
       eddsa_pk_to_EVP_PKEY(const eddsa_pk_t *pk);

DESCRIPTION

       EDDSA is the name given in the CBOR Object Signing and Encryption (COSE) RFC  to  EDDSA  over  Curve25519
       with  SHA-512.   The  COSE EDDSA API of libfido2 is an auxiliary API with routines to convert between the
       different EDDSA public key types used in libfido2 and OpenSSL.

       In libfido2, EDDSA public keys are abstracted by the eddsa_pk_t type.

       The eddsa_pk_new() function returns a pointer to a newly allocated, empty  eddsa_pk_t  type.   If  memory
       cannot be allocated, NULL is returned.

       The  eddsa_pk_free()  function  releases  the  memory  backing *pkp, where *pkp must have been previously
       allocated by eddsa_pk_new().  On return, *pkp is set to NULL.  Either pkp or *pkp may be NULL,  in  which
       case eddsa_pk_free() is a NOP.

       The  eddsa_pk_from_EVP_PKEY()  function  fills  pk  with the contents of pkey.  No references to pkey are
       kept.

       The eddsa_pk_from_ptr() function fills pk with the contents of ptr, where ptr points to  len  bytes.   No
       references to ptr are kept.

       The eddsa_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,
       eddsa_pk_to_EVP_PKEY() returns NULL.

RETURN VALUES

       The eddsa_pk_from_EC_KEY() and eddsa_pk_from_ptr() functions return FIDO_OK  on  success.   On  error,  a
       different error code defined in <fido/err.h> is returned.

SEE ALSO

       es256_pk_new(3), fido_assert_verify(3), fido_cred_pubkey_ptr(3), rs256_pk_new(3)

Debian                                            May 15, 2019                                   EDDSA_PK_NEW(3)