Updated: 2020/Jul/29


FIDO_CRED_SET_AUTHDATA(3)  Library Functions Manual  FIDO_CRED_SET_AUTHDATA(3)

NAME
     fido_cred_set_authdata, fido_cred_set_authdata_raw, fido_cred_set_x509,
     fido_cred_set_sig, fido_cred_set_clientdata_hash, fido_cred_set_rp,
     fido_cred_set_user, fido_cred_set_extensions, fido_cred_set_prot,
     fido_cred_set_rk, fido_cred_set_uv, fido_cred_set_fmt, fido_cred_set_type
     - set parameters of a FIDO 2 credential

SYNOPSIS
     #include <fido.h>

     typedef enum {
             FIDO_OPT_OMIT = 0, /* use authenticator's default */
             FIDO_OPT_FALSE,    /* explicitly set option to false */
             FIDO_OPT_TRUE,     /* explicitly set option to true */
     } fido_opt_t;
     int
     fido_cred_set_authdata(fido_cred_t *cred, const unsigned char *ptr,
         size_t len);

     int
     fido_cred_set_authdata_raw(fido_cred_t *cred, const unsigned char *ptr,
         size_t len);

     int
     fido_cred_set_x509(fido_cred_t *cred, const unsigned char *ptr,
         size_t len);

     int
     fido_cred_set_sig(fido_cred_t *cred, const unsigned char *ptr,
         size_t len);

     int
     fido_cred_set_clientdata_hash(fido_cred_t *cred,
         const unsigned char *ptr, size_t len);

     int
     fido_cred_set_rp(fido_cred_t *cred, const char *id, const char *name);

     int
     fido_cred_set_user(fido_cred_t *cred, const unsigned char *user_id,
         size_t user_id_len, const char *name, const char *display_name,
         const char *icon);

     int
     fido_cred_set_extensions(fido_cred_t *cred, int flags);

     int
     fido_cred_set_prot(fido_cred_t *cred, int prot);

     int
     fido_cred_set_rk(fido_cred_t *cred, fido_opt_t rk);

     int
     fido_cred_set_uv(fido_cred_t *cred, fido_opt_t uv);

     int
     fido_cred_set_fmt(fido_cred_t *cred, const char *ptr);

     int
     fido_cred_set_type(fido_cred_t *cred, int cose_alg);

DESCRIPTION
     The fido_cred_set_authdata set of functions define the various parameters
     of a FIDO 2 credential, allowing a fido_cred_t type to be prepared for a
     subsequent call to fido_dev_make_cred(3) or fido_cred_verify(3).  For the
     complete specification of a FIDO 2 credential and the format of its
     constituent parts, please refer to the Web Authentication (webauthn)
     standard.

     The fido_cred_set_authdata(), fido_cred_set_x509(), fido_cred_set_sig(),
     and fido_cred_set_clientdata_hash() functions set the authenticator data,
     attestation certificate, signature and client data hash parts of cred to
     ptr, where ptr points to len bytes.  A copy of ptr is made, and no
     references to the passed pointer are kept.  The authenticator data passed
     to fido_cred_set_authdata() must be a CBOR-encoded byte string, as
     obtained from fido_cred_authdata_ptr().  Alternatively, a raw binary blob
     may be passed to fido_cred_set_authdata_raw().

     The fido_cred_set_rp() function sets the relying party id and name
     parameters of cred, where id and name are NUL-terminated UTF-8 strings.
     The contents of id and name are copied, and no references to the passed
     pointers are kept.

     The fido_cred_set_user() function sets the user attributes of cred, where
     user_id points to user_id_len bytes and name, display_name, and icon are
     NUL-terminated UTF-8 strings.  The contents of user_id, name,
     display_name, and icon are copied, and no references to the passed
     pointers are kept.  Previously set user attributes are flushed.  The
     user_id, name, display_name, and icon parameters may be NULL.

     The fido_cred_set_extensions() function sets the extensions of cred to
     the bitmask flags.  At the moment, only the FIDO_EXT_HMAC_SECRET and
     FIDO_EXT_CRED_PROTECT extensions are supported.  If flags is zero, the
     extensions of cred are cleared.

     The fido_cred_set_prot() function sets the protection of cred to the
     scalar prot.  At the moment, only the FIDO_CRED_PROT_UV_OPTIONAL,
     FIDO_CRED_PROT_UV_OPTIONAL_WITH_ID, and FIDO_CRED_PROT_UV_REQUIRED
     protections are supported.  If prot is zero, the protection of cred is
     cleared.

     The fido_cred_set_rk() and fido_cred_set_uv() functions set the rk
     (resident key) and uv (user verification) attributes of cred.  Both are
     FIDO_OPT_OMIT by default, allowing the authenticator to use its default
     settings.

     The fido_cred_set_fmt() function sets the format of cred to fmt, where
     fmt must be either packed (the format used in FIDO 2) or fido-u2f (the
     format used by U2F).  A copy of fmt is made, and no references to the
     passed pointer are kept.  Note that not all authenticators support FIDO2
     and therefore may not be able to generate packed.

     The fido_cred_set_type() function sets the type of cred to cose_alg,
     where cose_alg is COSE_ES256, COSE_RS256, or COSE_EDDSA.  The type of a
     credential may only be set once.  Note that not all authenticators
     support COSE_RS256 or COSE_EDDSA.

     Use of the fido_cred_set_authdata set of functions may happen in two
     distinct situations: when generating a new credential on a FIDO device,
     prior to fido_dev_make_cred(3) (i.e, in the context of a FIDO client), or
     when validating a generated credential using fido_cred_verify(3) (i.e, in
     the context of a FIDO server).

     For a complete description of the generation of a FIDO 2 credential and
     its verification, please refer to the FIDO 2 specification.  A concrete
     utilisation example of the fido_cred_set_authdata set of functions can be
     found in the cred.c example shipped with libfido2.

RETURN VALUES
     The error codes returned by the fido_cred_set_authdata set of functions
     are defined in <fido/err.h>.  On success, FIDO_OK is returned.

SEE ALSO
     fido_cred_exclude(3), fido_cred_verify(3), fido_dev_make_cred(3)

NetBSD 9.99                $Mdocdate: May 23 2018 $                NetBSD 9.99