fido_cbor_info_new,
  
fido_cbor_info_free,
  
fido_dev_get_cbor_info,
  
fido_cbor_info_aaguid_ptr,
  
fido_cbor_info_extensions_ptr,
  
fido_cbor_info_protocols_ptr,
  
fido_cbor_info_transports_ptr,
  
fido_cbor_info_versions_ptr,
  
fido_cbor_info_options_name_ptr,
  
fido_cbor_info_options_value_ptr,
  
fido_cbor_info_algorithm_type,
  
fido_cbor_info_algorithm_cose,
  
fido_cbor_info_algorithm_count,
  
fido_cbor_info_certs_name_ptr,
  
fido_cbor_info_certs_value_ptr,
  
fido_cbor_info_certs_len,
  
fido_cbor_info_aaguid_len,
  
fido_cbor_info_extensions_len,
  
fido_cbor_info_protocols_len,
  
fido_cbor_info_transports_len,
  
fido_cbor_info_versions_len,
  
fido_cbor_info_options_len,
  
fido_cbor_info_maxmsgsiz,
  
fido_cbor_info_maxcredbloblen,
  
fido_cbor_info_maxcredcntlst,
  
fido_cbor_info_maxcredidlen,
  
fido_cbor_info_maxlargeblob,
  
fido_cbor_info_maxrpid_minpinlen,
  
fido_cbor_info_minpinlen,
  
fido_cbor_info_fwversion,
  
fido_cbor_info_uv_attempts,
  
fido_cbor_info_uv_modality,
  
fido_cbor_info_rk_remaining,
  
fido_cbor_info_new_pin_required —
FIDO2 CBOR Info API
#include
  <fido.h>
fido_cbor_info_t *
fido_cbor_info_new(
void);
void
fido_cbor_info_free(
fido_cbor_info_t
  **ci_p);
int
fido_dev_get_cbor_info(
fido_dev_t
  *dev,
  
fido_cbor_info_t
  *ci);
const unsigned char *
fido_cbor_info_aaguid_ptr(
const
  fido_cbor_info_t *ci);
char **
fido_cbor_info_extensions_ptr(
const
  fido_cbor_info_t *ci);
const uint8_t *
fido_cbor_info_protocols_ptr(
const
  fido_cbor_info_t *ci);
char **
fido_cbor_info_transports_ptr(
const
  fido_cbor_info_t *ci);
char **
fido_cbor_info_versions_ptr(
const
  fido_cbor_info_t *ci);
char **
fido_cbor_info_options_name_ptr(
const
  fido_cbor_info_t *ci);
const bool *
fido_cbor_info_options_value_ptr(
const
  fido_cbor_info_t *ci);
const char *
fido_cbor_info_algorithm_type(
const
  fido_cbor_info_t *ci,
  
size_t idx);
int
fido_cbor_info_algorithm_cose(
const
  fido_cbor_info_t *ci,
  
size_t idx);
size_t
fido_cbor_info_algorithm_count(
const
  fido_cbor_info_t *ci);
char **
fido_cbor_info_certs_name_ptr(
const
  fido_cbor_info_t *ci);
const uint64_t *
fido_cbor_info_certs_value_ptr(
const
  fido_cbor_info_t *ci);
size_t
fido_cbor_info_certs_len(
const
  fido_cbor_info_t *ci);
size_t
fido_cbor_info_aaguid_len(
const
  fido_cbor_info_t *ci);
size_t
fido_cbor_info_extensions_len(
const
  fido_cbor_info_t *ci);
size_t
fido_cbor_info_protocols_len(
const
  fido_cbor_info_t *ci);
size_t
fido_cbor_info_transports_len(
const
  fido_cbor_info_t *ci);
size_t
fido_cbor_info_versions_len(
const
  fido_cbor_info_t *ci);
size_t
fido_cbor_info_options_len(
const
  fido_cbor_info_t *ci);
uint64_t
fido_cbor_info_maxmsgsiz(
const
  fido_cbor_info_t *ci);
uint64_t
fido_cbor_info_maxcredbloblen(
const
  fido_cbor_info_t *ci);
uint64_t
fido_cbor_info_maxcredcntlst(
const
  fido_cbor_info_t *ci);
uint64_t
fido_cbor_info_maxcredidlen(
const
  fido_cbor_info_t *ci);
uint64_t
fido_cbor_info_maxlargeblob(
const
  fido_cbor_info_t *ci);
uint64_t
fido_cbor_info_maxrpid_minpinlen(
const
  fido_cbor_info_t *ci);
uint64_t
fido_cbor_info_minpinlen(
const
  fido_cbor_info_t *ci);
uint64_t
fido_cbor_info_fwversion(
const
  fido_cbor_info_t *ci);
uint64_t
fido_cbor_info_uv_attempts(
const
  fido_cbor_info_t *ci);
uint64_t
fido_cbor_info_uv_modality(
const
  fido_cbor_info_t *ci);
int64_t
fido_cbor_info_rk_remaining(
const
  fido_cbor_info_t *ci);
bool
fido_cbor_info_new_pin_required(
const
  fido_cbor_info_t *ci);
The 
fido_cbor_info_new() function returns a
  pointer to a newly allocated, empty
  
fido_cbor_info_t type. If memory cannot be
  allocated, NULL is returned.
The 
fido_cbor_info_free() function releases
  the memory backing 
*ci_p, where
  
*ci_p must have been previously allocated by
  
fido_cbor_info_new(). On return,
  
*ci_p is set to NULL. Either
  
ci_p or
  
*ci_p may be NULL, in which case
  
fido_cbor_info_free() is a NOP.
The 
fido_dev_get_cbor_info() function
  transmits a 
CTAP_CBOR_GETINFO command to
  
dev and fills
  
ci with attributes retrieved from the
  command's response. The
  
fido_dev_get_cbor_info() function may
  block.
The 
fido_cbor_info_aaguid_ptr(),
  
fido_cbor_info_extensions_ptr(),
  
fido_cbor_info_protocols_ptr(),
  
fido_cbor_info_transports_ptr(), and
  
fido_cbor_info_versions_ptr() functions
  return pointers to the authenticator attestation GUID, supported extensions,
  PIN protocol, transports, and CTAP version strings of
  
ci. The corresponding length of a given
  attribute can be obtained by
  
fido_cbor_info_aaguid_len(),
  
fido_cbor_info_extensions_len(),
  
fido_cbor_info_protocols_len(),
  
fido_cbor_info_transports_len(), or
  
fido_cbor_info_versions_len().
The 
fido_cbor_info_options_name_ptr() and
  
fido_cbor_info_options_value_ptr()
  functions return pointers to the array of option names and their respective
  values in 
ci. The length of the options array
  is returned by
  
fido_cbor_info_options_len().
The 
fido_cbor_info_algorithm_count() function
  returns the number of supported algorithms in
  
ci. The
  
fido_cbor_info_algorithm_cose() function
  returns the COSE identifier of algorithm 
idx
  in 
ci, or 0 if the COSE identifier is unknown
  or unset. The
  
fido_cbor_info_algorithm_type() function
  returns the type of algorithm 
idx in
  
ci, or NULL if the type is unset. Please note
  that the first algorithm in 
ci has an
  
idx (index) value of 0.
The 
fido_cbor_info_certs_name_ptr() and
  
fido_cbor_info_certs_value_ptr() functions
  return pointers to the array of certification names and their respective
  values in 
ci. The length of the
  certifications array is returned by
  
fido_cbor_info_certs_len().
The 
fido_cbor_info_maxmsgsiz() function
  returns the maximum message size attribute of
  
ci.
The 
fido_cbor_info_maxcredbloblen() function
  returns the maximum “credBlob” length in bytes supported by the
  authenticator as reported in 
ci.
The 
fido_cbor_info_maxcredcntlst() function
  returns the maximum supported number of credentials in a single credential ID
  list as reported in 
ci.
The 
fido_cbor_info_maxcredidlen() function
  returns the maximum supported length of a credential ID as reported in
  
ci.
The 
fido_cbor_info_maxrpid_minpinlen()
  function returns the maximum number of RP IDs that may be passed to
  
fido_dev_set_pin_minlen_rpid(3),
  as reported in 
ci. The minimum PIN length
  attribute is a CTAP 2.1 addition. If the attribute is not advertised by the
  authenticator, the
  
fido_cbor_info_maxrpid_minpinlen() function
  returns zero.
The 
fido_cbor_info_maxlargeblob() function
  returns the maximum length in bytes of an authenticator's serialized largeBlob
  array as reported in 
ci.
The 
fido_cbor_info_minpinlen() function
  returns the minimum PIN length enforced by the authenticator as reported in
  
ci. The minimum PIN length attribute is a
  CTAP 2.1 addition. If the attribute is not advertised by the authenticator,
  the 
fido_cbor_info_minpinlen() function
  returns zero.
The 
fido_cbor_info_fwversion() function
  returns the firmware version attribute of 
ci.
The 
fido_cbor_info_uv_attempts() function
  returns the number of UV attempts that the platform may attempt before falling
  back to PIN authentication. If 1, then all
  
fido_dev_get_uv_retry_count(3)
  retries are handled internally by the authenticator and the platform may only
  attempt non-PIN UV once. The UV attempts attribute is a CTAP 2.1 addition. If
  the attribute is not advertised by the authenticator, the
  
fido_cbor_info_uv_attempts() function
  returns zero.
The 
fido_cbor_info_uv_modality() function
  returns a bitmask representing different UV modes supported by the
  authenticator, as defined in the FIDO Registry of Predefined Values and
  reported in 
ci. See the
  
FIDO_UV_MODE_* definitions in
  
<fido/param.h>
  for the set of values defined by libfido2 and a brief description of each. The
  UV modality attribute is a CTAP 2.1 addition. If the attribute is not
  advertised by the authenticator, the
  
fido_cbor_info_uv_modality() function
  returns zero.
The 
fido_cbor_info_rk_remaining() function
  returns the estimated number of additional resident/discoverable credentials
  that can be stored on the authenticator as reported in
  
ci. The estimated number of remaining
  resident credentials is a CTAP 2.1 addition. If the attribute is not
  advertised by the authenticator, the
  
fido_cbor_info_rk_remaining() function
  returns -1.
The 
fido_cbor_info_new_pin_required()
  function returns whether a new PIN is required by the authenticator as
  reported in 
ci. If
  
fido_cbor_info_new_pin_required() returns
  true, operations requiring PIN authentication will fail until a new PIN is set
  on the authenticator. The
  
fido_dev_set_pin(3)
  function can be used to set a new PIN.
A complete example of how to use these functions can be found in the
  
example/info.c file shipped with
  
libfido2.
The 
fido_cbor_info_aaguid_ptr(),
  
fido_cbor_info_extensions_ptr(),
  
fido_cbor_info_protocols_ptr(),
  
fido_cbor_info_transports_ptr(),
  
fido_cbor_info_versions_ptr(),
  
fido_cbor_info_options_name_ptr(), and
  
fido_cbor_info_options_value_ptr()
  functions return NULL if the respective field in
  
ci is absent. If not NULL, returned pointers
  are guaranteed to exist until any API function that takes
  
ci without the
  
const qualifier is invoked.
fido_dev_get_uv_retry_count(3),
  
fido_dev_open(3),
  
fido_dev_set_pin(3),
  
fido_dev_set_pin_minlen_rpid(3)
FIDO Registry of Predefined
  Values,
  https://fidoalliance.org/specs/common-specs/fido-registry-v2.2-rd-20210525.html,
  FIDO Alliance, 2021-05-25,
  Review Draft, Version 2.2.