NAME

       rs256_pk_new,     rs256_pk_free,     rs256_pk_from_RSA,     rs256_pk_from_EVP_PKEY,    rs256_pk_from_ptr,
       rs256_pk_to_EVP_PKEY — FIDO2 COSE RS256 API

SYNOPSIS

       #include <openssl/rsa.h>
       #include <fido/rs256.h>

       rs256_pk_t *
       rs256_pk_new(void);

       void
       rs256_pk_free(rs256_pk_t **pkp);

       int
       rs256_pk_from_EVP_PKEY(rs256_pk_t *pk, const EVP_PKEY *pkey);

       int
       rs256_pk_from_RSA(rs256_pk_t *pk, const RSA *rsa);

       int
       rs256_pk_from_ptr(rs256_pk_t *pk, const void *ptr, size_t len);

       EVP_PKEY *
       rs256_pk_to_EVP_PKEY(const rs256_pk_t *pk);

DESCRIPTION

       RS256 is the name given in the CBOR Object Signing and Encryption (COSE) RFC  to  PKCS#1.5  2048-bit  RSA
       with  SHA-256.   The  COSE RS256 API of libfido2 is an auxiliary API with routines to convert between the
       different RSA public key types used in libfido2 and OpenSSL.

       In libfido2, RS256 public keys are abstracted by the rs256_pk_t type.

       The rs256_pk_new() function returns a pointer to a newly allocated, empty  rs256_pk_t  type.   If  memory
       cannot be allocated, NULL is returned.

       The  rs256_pk_free()  function  releases  the  memory  backing *pkp, where *pkp must have been previously
       allocated by rs256_pk_new().  On return, *pkp is set to NULL.  Either pkp or *pkp may be NULL,  in  which
       case rs256_pk_free() is a NOP.

       The  rs256_pk_from_EVP_PKEY()  function  fills  pk  with the contents of pkey.  No references to pkey are
       kept.

       The rs256_pk_from_RSA() function fills pk with the contents of rsa.  No references to rsa are kept.

       The rs256_pk_from_ptr() function fills pk with the contents of ptr, where ptr points to  len  bytes.   No
       references to ptr are kept.

       The rs256_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,
       rs256_pk_to_EVP_PKEY() returns NULL.

RETURN VALUES

       The rs256_pk_from_EVP_PKEY(), rs256_pk_from_RSA(), and rs256_pk_from_ptr() functions  return  FIDO_OK  on
       success.  On error, a different error code defined in <fido/err.h> is returned.

SEE ALSO

       eddsa_pk_new(3), es256_pk_new(3), es384_pk_new(3), fido_assert_verify(3), fido_cred_pubkey_ptr(3)

Debian                                            July 15, 2022                                  RS256_PK_NEW(3)