FIDO2 storage layer using secure-element ECC slots, R-Memory, and NVS counters. More...

#include "mod_fido2/fido2_storage.h"
#include "mod_fido2/fido2_common.h"
#include "cdc_hal/ISecureElement.h"
#include "cdc_log.h"
#include "esp_attr.h"
#include <mbedtls/sha256.h>
#include <nvs_flash.h>
#include <nvs.h>
#include <string.h>

Classes
struct	cdc::mod_fido2::fido2_stored_cred_t

Namespaces
namespace	cdc
namespace	cdc::mod_fido2

Macros
#define	FIDO2_RMEM_MAGIC "FID2"
	Persistent storage layout definitions.
#define	FIDO2_RMEM_MAGIC_LEN 4
#define	NVS_NAMESPACE "fido2"
#define	NVS_KEY_COUNTER "auth_cnt"
#define	FIDO2_STORED_SIZE sizeof(fido2_stored_cred_t)
#define	FIDO2_FLAG_RESIDENT 0x01
	Stored-credential flag bits.

Functions
void	fido2_storage_set_slot_range (uint8_t ecc_start, uint8_t ecc_end, uint16_t rmem_start, uint16_t rmem_end)
	Configures FIDO2 storage slot ranges.
uint8_t	fido2_storage_ecc_start (void)
	Returns configured ECC start slot.
uint8_t	fido2_storage_ecc_end (void)
	Returns configured ECC end slot.
uint16_t	fido2_storage_rmem_start (void)
	Returns configured RMEM start slot.
uint16_t	fido2_storage_rmem_end (void)
	Returns configured RMEM end slot.
static bool	slot_range_valid (void)
	Validates slot-range configuration.
static uint16_t	ecc_count (void)
	Returns number of configured logical ECC slots.
static uint16_t	rmem_count (void)
	Returns number of configured logical RMEM slots.
static bool	slot_logical_valid (uint8_t slot)
	Checks whether logical slot index is within range.
static uint8_t	ecc_slot_for_logical (uint8_t slot)
	Maps logical slot to physical ECC slot.
static uint16_t	rmem_slot_for_logical (uint8_t slot)
	Maps logical slot to physical RMEM slot.
static bool	read_rmem_credential (uint8_t logical_slot, fido2_stored_cred_t *stored)
	Internal helper functions for slot and cache management.
static void	update_cache_from_stored (uint8_t slot, const fido2_stored_cred_t *stored, bool is_resident)
	Updates cache entry from stored credential payload.
static void	erase_slot_data (uint8_t logical_slot)
	Erases ECC key material and R-Memory data for a logical slot.
static uint8_t *	encode_der_integer (uint8_t p, const uint8_t mpi)
	Encodes a single ECDSA P-256 component (R or S) as a DER INTEGER.
static uint8_t	raw_sig_to_der (const uint8_t raw_sig[FIDO2_SIG_SIZE], uint8_t *der_sig)
	Converts raw 64-byte ECDSA signature (R\|\|S) to DER sequence format.
static bool	write_rmem_credential (uint8_t logical_slot, const fido2_stored_cred_t *stored)
	Writes credential metadata to R-Memory after erasing the destination slot.
void	fido2_storage_counter_load (void)
	NVS-backed global authentication counter operations.
uint32_t	fido2_storage_counter_get (void)
	Returns current global authentication counter.
bool	fido2_storage_counter_increment (void)
	Increments and persists global authentication counter.
bool	fido2_storage_counter_flush (void)
	No-op flush retained for API stability; per-increment path commits.
uint8_t	fido2_storage_init (void)
	Initialization and cache rebuild routines.
uint8_t	fido2_storage_count (void)
	Credential lookup operations using in-memory cache only.
bool	fido2_storage_slot_used (uint8_t slot)
	Checks whether logical slot is occupied.
int8_t	fido2_storage_find_free_slot (void)
	Finds first unused logical slot.
uint8_t	fido2_storage_find_by_rp (const uint8_t rp_id_hash, uint8_t out_slots, uint8_t max_slots)
	Finds credentials matching RP hash.
uint8_t	fido2_storage_find_by_rp_resident (const uint8_t rp_id_hash, uint8_t out_slots, uint8_t max_slots)
	Finds resident credentials matching RP hash.
bool	fido2_storage_is_resident (uint8_t slot)
	Returns resident-key flag for slot.
int8_t	fido2_storage_find_by_rp_user (const uint8_t rp_id_hash, const uint8_t user_id, uint8_t user_id_len)
	Finds credential by RP hash and user handle for replacement logic.
int8_t	fido2_storage_find_slot_by_cred_id (const uint8_t *cred_id, uint16_t cred_id_len)
	Resolves and verifies logical slot from credential-id blob.
bool	fido2_storage_get_user (uint8_t slot, uint8_t user_id, uint8_t user_id_len, char *user_name, size_t user_name_max)
	Loads user handle and optional user name for a credential slot.
bool	fido2_storage_verify_cred_id (uint8_t slot, const uint8_t *cred_id)
	Verifies credential-id for logical slot.
bool	fido2_storage_get_cred_id (uint8_t slot, uint8_t *out_cred_id)
	Builds credential-id blob for logical slot.
bool	fido2_storage_get_credential (uint8_t slot, fido2_credential_info_t *info)
	Credential create/read/delete operations.
uint8_t	fido2_storage_get_curve (uint8_t slot)
	Returns stored curve identifier for slot.
bool	fido2_storage_create_credential (const char rp_id, const uint8_t rp_id_hash, const uint8_t user_id, uint8_t user_id_len, const char user_name, bool resident_key, uint8_t cred_protect, uint8_t curve, uint8_t out_slot, uint8_t out_cred_id, uint8_t *out_pubkey)
	Creates or replaces credential in secure-element storage.
bool	fido2_storage_delete_credential (uint8_t slot)
	Deletes credential and associated slot data.
uint32_t	fido2_storage_increment_sign_count (uint8_t slot)
	Increments per-credential sign counter and persists metadata.
bool	fido2_storage_sign (uint8_t slot, const uint8_t msg, uint16_t msg_len, uint8_t signature, uint8_t *sig_len)
	Signing operations requiring secure-element access.
bool	fido2_storage_sign_raw (uint8_t slot, const uint8_t msg, uint16_t msg_len, uint8_t signature, uint8_t *sig_len)
	Signs message and returns raw signature (EdDSA/ECDSA).
bool	fido2_storage_sign_der (uint8_t slot, const uint8_t msg, uint16_t msg_len, uint8_t signature, uint8_t *sig_len)
	Signs data and returns DER-encoded signature for U2F compatibility.
bool	fido2_storage_get_pubkey (uint8_t slot, uint8_t *pubkey)
	Reads public key from secure-element slot.
void	sha256 (const uint8_t *data, size_t len, uint8_t out[32])

Variables
static const char *	TAG = "FIDO2"
struct {
bool initialized
uint32_t auth_counter
bool counter_loaded
struct {
bool valid
uint8_t rp_id_hash [32]
char rp_id [FIDO2_RP_ID_MAX_LEN]
char user_name [FIDO2_USER_NAME_MAX_LEN]
uint8_t user_id [FIDO2_USER_ID_MAX_LEN]
uint8_t user_id_len
uint32_t sign_count
bool resident
uint8_t cred_protect
uint8_t curve
} creds [FIDO2_MAX_CREDENTIALS]
uint8_t cred_count
}	g_storage = {}
	Runtime storage/cache state.
static uint8_t	s_ecc_start = 0
static uint8_t	s_ecc_end = 0
static uint16_t	s_rmem_start = 0
static uint16_t	s_rmem_end = 0
static constexpr uint8_t	DER_TAG_SEQUENCE = 0x30
	DER ASN.1 tags used for ECDSA signature encoding.
static constexpr uint8_t	DER_TAG_INTEGER = 0x02
static constexpr uint8_t	DER_INTEGER_MSB_MASK = 0x80
	MSB mask used to detect when DER INTEGER needs a 0x00 padding byte.

Detailed Description

FIDO2 storage layer using secure-element ECC slots, R-Memory, and NVS counters.

Definition in file fido2_storage.cpp.

Macro Definition Documentation

◆ FIDO2_FLAG_RESIDENT

#define FIDO2_FLAG_RESIDENT 0x01

Stored-credential flag bits.

Definition at line 55 of file fido2_storage.cpp.

Referenced by fido2_storage_create_credential(), and fido2_storage_init().

◆ FIDO2_RMEM_MAGIC

#define FIDO2_RMEM_MAGIC "FID2"

Persistent storage layout definitions.

Definition at line 22 of file fido2_storage.cpp.

Referenced by fido2_storage_create_credential(), and read_rmem_credential().

◆ FIDO2_RMEM_MAGIC_LEN

#define FIDO2_RMEM_MAGIC_LEN 4

Definition at line 23 of file fido2_storage.cpp.

Referenced by fido2_storage_create_credential(), and read_rmem_credential().

◆ FIDO2_STORED_SIZE

#define FIDO2_STORED_SIZE sizeof(fido2_stored_cred_t)

Definition at line 52 of file fido2_storage.cpp.

Referenced by read_rmem_credential(), and write_rmem_credential().

◆ NVS_KEY_COUNTER

#define NVS_KEY_COUNTER "auth_cnt"

Definition at line 25 of file fido2_storage.cpp.

Referenced by fido2_storage_counter_increment(), and fido2_storage_counter_load().

◆ NVS_NAMESPACE

#define NVS_NAMESPACE "fido2"

Definition at line 24 of file fido2_storage.cpp.

Referenced by fido2_storage_counter_increment(), fido2_storage_counter_load(), load_state_from_nvs(), and save_state_to_nvs().

Function Documentation

◆ ecc_count()

uint16_t ecc_count ( void )

static

Returns number of configured logical ECC slots.

Returns: ECC slot count.

Definition at line 137 of file fido2_storage.cpp.

References s_ecc_end, s_ecc_start, and slot_range_valid().

Referenced by fido2_storage_find_by_rp(), fido2_storage_find_by_rp_resident(), fido2_storage_find_by_rp_user(), fido2_storage_find_free_slot(), fido2_storage_init(), and slot_logical_valid().

◆ ecc_slot_for_logical()

uint8_t ecc_slot_for_logical ( uint8_t slot )

static

Maps logical slot to physical ECC slot.

Parameters

slot	Logical slot index.

Returns: Physical ECC slot.

Definition at line 166 of file fido2_storage.cpp.

References s_ecc_start.

Referenced by erase_slot_data(), fido2_storage_create_credential(), fido2_storage_get_pubkey(), fido2_storage_sign(), fido2_storage_sign_der(), and fido2_storage_sign_raw().

◆ encode_der_integer()

uint8_t * encode_der_integer	(	uint8_t *	p,
		const uint8_t *	mpi )

static

Encodes a single ECDSA P-256 component (R or S) as a DER INTEGER.

Parameters

p	Output cursor (advances past written bytes).
mpi	Big-endian magnitude buffer of length FIDO2_SIG_COMPONENT_SIZE.

Returns: Updated output cursor positioned after the encoded INTEGER.

Strips leading zero bytes (keeping at least one) and prepends a 0x00 padding byte when the MSB is set, ensuring the integer remains non-negative in DER.

Definition at line 267 of file fido2_storage.cpp.

References DER_INTEGER_MSB_MASK, DER_TAG_INTEGER, and FIDO2_SIG_COMPONENT_SIZE.

Referenced by raw_sig_to_der().

◆ erase_slot_data()

void erase_slot_data ( uint8_t logical_slot )

static

Erases ECC key material and R-Memory data for a logical slot.

Parameters

logical_slot Logical credential slot index.

Returns: void

Definition at line 241 of file fido2_storage.cpp.

References ecc_slot_for_logical(), cdc::hal::getSecureElementInstance(), and rmem_slot_for_logical().

Referenced by fido2_storage_create_credential(), and fido2_storage_delete_credential().

◆ fido2_storage_count()

uint8_t fido2_storage_count ( void )

Credential lookup operations using in-memory cache only.

Returns number of cached credentials.

Returns: Credential count.

Definition at line 469 of file fido2_storage.cpp.

References g_storage.

Referenced by fido2_get_available_slots(), and fido2_get_credential_count().

◆ fido2_storage_counter_flush()

bool fido2_storage_counter_flush ( void )

No-op flush retained for API stability; per-increment path commits.

Returns: Always true.

Definition at line 413 of file fido2_storage.cpp.

Referenced by cdc::mod_fido2::Fido2Module::stop().

◆ fido2_storage_counter_get()

uint32_t fido2_storage_counter_get ( void )

Returns current global authentication counter.

Returns: Counter value.

Definition at line 366 of file fido2_storage.cpp.

References fido2_storage_counter_load(), and g_storage.

Referenced by fido2_get_auth_counter().

◆ fido2_storage_counter_increment()

bool fido2_storage_counter_increment ( void )

Increments and persists global authentication counter.

Returns: true on successful persistence.

Definition at line 377 of file fido2_storage.cpp.

References fido2_storage_counter_load(), g_storage, LOG_E, NVS_KEY_COUNTER, NVS_NAMESPACE, and TAG.

Referenced by fido2_increment_auth_counter().

◆ fido2_storage_counter_load()

void fido2_storage_counter_load ( void )

NVS-backed global authentication counter operations.

Loads global authentication counter from NVS.

Definition at line 336 of file fido2_storage.cpp.

References g_storage, LOG_I, LOG_W, NVS_KEY_COUNTER, NVS_NAMESPACE, and TAG.

Referenced by fido2_storage_counter_get(), fido2_storage_counter_increment(), and fido2_storage_init().

◆ fido2_storage_create_credential()

bool fido2_storage_create_credential	(	const char *	rp_id,
		const uint8_t *	rp_id_hash,
		const uint8_t *	user_id,
		uint8_t	user_id_len,
		const char *	user_name,
		bool	resident_key,
		uint8_t	cred_protect,
		uint8_t	curve,
		uint8_t *	out_slot,
		uint8_t *	out_cred_id,
		uint8_t *	out_pubkey )

Creates or replaces credential in secure-element storage.

Parameters

rp_id	Relying-party id string.
rp_id_hash	RP ID hash (32 bytes).
user_id	User handle bytes.
user_id_len	User handle length.
user_name	User display name.
resident_key	Resident-key flag.
cred_protect	Credential protection policy.
curve	Requested key curve.
out_slot	Output logical slot.
out_cred_id	Output credential-id.
out_pubkey	Output public key bytes.

Returns: true on success.

Definition at line 759 of file fido2_storage.cpp.

References CDC_CURVE_ED25519, cred_protect, curve, ecc_slot_for_logical(), cdc::hal::ED25519, erase_slot_data(), FIDO2_CRED_ID_LEN, FIDO2_FLAG_RESIDENT, FIDO2_RMEM_MAGIC, FIDO2_RMEM_MAGIC_LEN, FIDO2_RP_ID_MAX_LEN, fido2_storage_find_by_rp_user(), fido2_storage_find_free_slot(), FIDO2_USER_ID_MAX_LEN, FIDO2_USER_NAME_MAX_LEN, g_storage, cdc::hal::getSecureElementInstance(), LOG_D, LOG_E, LOG_I, cdc::hal::OK, cdc::hal::P256, rp_id, rp_id_hash, TAG, update_cache_from_stored(), user_id, user_id_len, user_name, and write_rmem_credential().

Referenced by cdc::mod_fido2::create_credential_and_respond(), and u2f_register().

◆ fido2_storage_delete_credential()

bool fido2_storage_delete_credential ( uint8_t slot )

Deletes credential and associated slot data.

Parameters

slot	Logical slot index.

Returns: true on success.

Definition at line 892 of file fido2_storage.cpp.

References erase_slot_data(), g_storage, LOG_I, slot_logical_valid(), and TAG.

Referenced by ctap2_cred_management(), fido2_delete_credential(), fido2_factory_reset(), cdc::mod_fido2::mc_rollback_credential(), and u2f_register().

◆ fido2_storage_ecc_end()

uint8_t fido2_storage_ecc_end ( void )

Returns configured ECC end slot.

Returns: ECC end slot index.

Definition at line 111 of file fido2_storage.cpp.

References s_ecc_end.

Referenced by fido2_get_available_slots().

◆ fido2_storage_ecc_start()

uint8_t fido2_storage_ecc_start ( void )

Returns configured ECC start slot.

Returns: ECC start slot index.

Definition at line 105 of file fido2_storage.cpp.

References s_ecc_start.

Referenced by fido2_get_available_slots(), and cdc::mod_fido2::showDetail().

◆ fido2_storage_find_by_rp()

uint8_t fido2_storage_find_by_rp	(	const uint8_t *	rp_id_hash,
		uint8_t *	out_slots,
		uint8_t	max_slots )

Finds credentials matching RP hash.

Parameters

rp_id_hash	RP ID hash (32 bytes).
out_slots	Output slot array.
max_slots	Maximum writable slots.

Returns: Number of matches.

Definition at line 504 of file fido2_storage.cpp.

References ecc_count(), FIDO2_MAX_CREDENTIALS, g_storage, and rp_id_hash.

Referenced by cdc::mod_fido2::check_appid_exclude(), fido2_find_credentials_by_rp(), and ga_find_credentials().

◆ fido2_storage_find_by_rp_resident()

uint8_t fido2_storage_find_by_rp_resident	(	const uint8_t *	rp_id_hash,
		uint8_t *	out_slots,
		uint8_t	max_slots )

Finds resident credentials matching RP hash.

Parameters

rp_id_hash	RP ID hash (32 bytes).
out_slots	Output slot array.
max_slots	Maximum writable slots.

Returns: Number of matches.

Definition at line 526 of file fido2_storage.cpp.

References ecc_count(), FIDO2_MAX_CREDENTIALS, g_storage, LOG_D, rp_id_hash, and TAG.

◆ fido2_storage_find_by_rp_user()

int8_t fido2_storage_find_by_rp_user	(	const uint8_t *	rp_id_hash,
		const uint8_t *	user_id,
		uint8_t	user_id_len )

Finds credential by RP hash and user handle for replacement logic.

Parameters

rp_id_hash	RP ID hash (32 bytes).
user_id	User handle bytes.
user_id_len	User handle length.

Returns: Matching slot index or -1.

Definition at line 564 of file fido2_storage.cpp.

References ecc_count(), FIDO2_MAX_CREDENTIALS, g_storage, LOG_D, rp_id_hash, TAG, user_id, and user_id_len.

Referenced by cdc::mod_fido2::ctap2_make_credential(), and fido2_storage_create_credential().

◆ fido2_storage_find_free_slot()

int8_t fido2_storage_find_free_slot ( void )

Finds first unused logical slot.

Returns: Logical slot index or -1 if full.

Definition at line 487 of file fido2_storage.cpp.

References ecc_count(), FIDO2_MAX_CREDENTIALS, and g_storage.

Referenced by fido2_storage_create_credential().

◆ fido2_storage_find_slot_by_cred_id()

int8_t fido2_storage_find_slot_by_cred_id	(	const uint8_t *	cred_id,
		uint16_t	cred_id_len )

Resolves and verifies logical slot from credential-id blob.

Parameters

cred_id	Credential ID bytes.
cred_id_len	Credential ID length.

Returns: Slot index or -1 on mismatch.

Definition at line 598 of file fido2_storage.cpp.

References FIDO2_CRED_ID_LEN, fido2_storage_get_cred_id(), g_storage, and slot_logical_valid().

Referenced by ctap2_cred_management(), ga_parse_allow_list(), and u2f_authenticate().

◆ fido2_storage_get_cred_id()

bool fido2_storage_get_cred_id	(	uint8_t	slot,
		uint8_t *	out_cred_id )

Builds credential-id blob for logical slot.

Parameters

slot	Logical slot index.
out_cred_id	Output credential-id buffer.

Returns: true on success.

Definition at line 679 of file fido2_storage.cpp.

References FIDO2_CRED_ID_LEN, g_storage, LOG_E, read_rmem_credential(), slot_logical_valid(), and TAG.

Referenced by cred_mgmt_encode_credential(), ctap2_get_assertion(), ctap2_get_next_assertion(), fido2_storage_find_slot_by_cred_id(), and fido2_storage_verify_cred_id().

◆ fido2_storage_get_credential()

bool fido2_storage_get_credential	(	uint8_t	slot,
		fido2_credential_info_t *	info )

Credential create/read/delete operations.

Returns cached credential metadata for slot.

Parameters

slot	Logical slot index.
info	Output credential info.

Returns: true on success.

Definition at line 706 of file fido2_storage.cpp.

References FIDO2_RP_ID_MAX_LEN, fido2_storage_get_user(), FIDO2_USER_NAME_MAX_LEN, g_storage, slot_logical_valid(), and user_id_len.

Referenced by cred_mgmt_count_unique_rps(), cred_mgmt_encode_credential(), cred_mgmt_encode_rp(), cred_mgmt_find_creds_for_rp(), ctap2_get_assertion(), ctap2_get_next_assertion(), fido2_get_credential_info(), ga_find_credentials(), and u2f_authenticate().

◆ fido2_storage_get_curve()

uint8_t fido2_storage_get_curve ( uint8_t slot )

Returns stored curve identifier for slot.

Parameters

slot	Logical slot index.

Returns: Curve id or 0xFF if invalid.

Definition at line 737 of file fido2_storage.cpp.

References g_storage, and slot_logical_valid().

◆ fido2_storage_get_pubkey()

bool fido2_storage_get_pubkey	(	uint8_t	slot,
		uint8_t *	pubkey )

Reads public key from secure-element slot.

Parameters

slot	Logical slot index.
pubkey	Output public-key buffer.

Returns: true on success.

Definition at line 1062 of file fido2_storage.cpp.

References curve, ecc_slot_for_logical(), cdc::hal::getSecureElementInstance(), cdc::hal::OK, cdc::hal::P256, and slot_logical_valid().

Referenced by cred_mgmt_encode_credential(), cred_mgmt_slot_has_key(), and cdc::mod_fido2::showDetail().

◆ fido2_storage_get_user()

bool fido2_storage_get_user	(	uint8_t	slot,
		uint8_t *	user_id,
		uint8_t *	user_id_len,
		char *	user_name,
		size_t	user_name_max )

Loads user handle and optional user name for a credential slot.

Parameters

slot	Logical slot index.
user_id	Output user-handle buffer.
user_id_len	Output user-handle length.
user_name	Output user-name buffer.
user_name_max	User-name buffer size.

Returns: true on success.

Definition at line 627 of file fido2_storage.cpp.

References FIDO2_USER_ID_MAX_LEN, FIDO2_USER_NAME_MAX_LEN, g_storage, read_rmem_credential(), slot_logical_valid(), user_id, user_id_len, and user_name.

Referenced by fido2_storage_get_credential().

◆ fido2_storage_increment_sign_count()

uint32_t fido2_storage_increment_sign_count ( uint8_t slot )

Increments per-credential sign counter and persists metadata.

Parameters

slot	Logical slot index.

Returns: New sign count or 0 on failure.

Definition at line 915 of file fido2_storage.cpp.

References g_storage, LOG_E, read_rmem_credential(), slot_logical_valid(), TAG, and write_rmem_credential().

Referenced by ctap2_get_assertion(), ctap2_get_next_assertion(), and u2f_authenticate().

◆ fido2_storage_init()

uint8_t fido2_storage_init ( void )

Initialization and cache rebuild routines.

Initializes FIDO2 storage cache from secure element and NVS.

Returns: Number of discovered credentials.

Definition at line 423 of file fido2_storage.cpp.

References ecc_count(), FIDO2_FLAG_RESIDENT, FIDO2_MAX_CREDENTIALS, fido2_storage_counter_load(), g_storage, cdc::hal::getSecureElementInstance(), LOG_D, LOG_E, LOG_I, read_rmem_credential(), rmem_count(), slot_range_valid(), TAG, and update_cache_from_stored().

Referenced by fido2_init().

◆ fido2_storage_is_resident()

bool fido2_storage_is_resident ( uint8_t slot )

Returns resident-key flag for slot.

Parameters

slot	Logical slot index.

Returns: true if resident credential.

Definition at line 552 of file fido2_storage.cpp.

References g_storage, and slot_logical_valid().

Referenced by cred_mgmt_count_unique_rps(), cred_mgmt_find_creds_for_rp(), and ctap2_cred_management().

◆ fido2_storage_rmem_end()

uint16_t fido2_storage_rmem_end ( void )

Returns configured RMEM end slot.

Returns: RMEM end slot index.

Definition at line 123 of file fido2_storage.cpp.

References s_rmem_end.

◆ fido2_storage_rmem_start()

uint16_t fido2_storage_rmem_start ( void )

Returns configured RMEM start slot.

Returns: RMEM start slot index.

Definition at line 117 of file fido2_storage.cpp.

References s_rmem_start.

◆ fido2_storage_set_slot_range()

void fido2_storage_set_slot_range	(	uint8_t	ecc_start,
		uint8_t	ecc_end,
		uint16_t	rmem_start,
		uint16_t	rmem_end )

Configures FIDO2 storage slot ranges.

Parameters

ecc_start	First ECC slot.
ecc_end	Last ECC slot.
rmem_start	First RMEM slot.
rmem_end	Last RMEM slot.

Definition at line 93 of file fido2_storage.cpp.

References s_ecc_end, s_ecc_start, s_rmem_end, and s_rmem_start.

Referenced by cdc::mod_fido2::Fido2Module::init().

◆ fido2_storage_sign()

bool fido2_storage_sign	(	uint8_t	slot,
		const uint8_t *	msg,
		uint16_t	msg_len,
		uint8_t *	signature,
		uint8_t *	sig_len )

Signing operations requiring secure-element access.

Signs message hash with ECDSA and returns DER signature.

Parameters

slot	Logical slot index.
Message transfer (badge-to-badge)	Message bytes.
msg_len	Message length.
signature	Output signature buffer.
sig_len	Output signature length.

Returns: true on success.

Definition at line 947 of file fido2_storage.cpp.

References ecc_slot_for_logical(), FIDO2_SIG_SIZE, g_storage, cdc::hal::getSecureElementInstance(), LOG_D, LOG_E, cdc::hal::OK, raw_sig_to_der(), slot_logical_valid(), and TAG.

◆ fido2_storage_sign_der()

bool fido2_storage_sign_der	(	uint8_t	slot,
		const uint8_t *	msg,
		uint16_t	msg_len,
		uint8_t *	signature,
		uint8_t *	sig_len )

Signs data and returns DER-encoded signature for U2F compatibility.

Signs message hash and returns DER-encoded ECDSA signature.

Parameters

slot	Logical slot index.
Message transfer (badge-to-badge)	Message bytes.
msg_len	Message length.
signature	Output DER buffer.
sig_len	Output DER length.

Returns: true on success.

Definition at line 1030 of file fido2_storage.cpp.

References ecc_slot_for_logical(), FIDO2_SIG_SIZE, g_storage, cdc::hal::getSecureElementInstance(), LOG_D, LOG_E, cdc::hal::OK, raw_sig_to_der(), slot_logical_valid(), and TAG.

◆ fido2_storage_sign_raw()

bool fido2_storage_sign_raw	(	uint8_t	slot,
		const uint8_t *	msg,
		uint16_t	msg_len,
		uint8_t *	signature,
		uint8_t *	sig_len )

Signs message and returns raw signature (EdDSA/ECDSA).

Parameters

slot	Logical slot index.
Message transfer (badge-to-badge)	Message bytes.
msg_len	Message length.
signature	Output raw signature buffer.
sig_len	Output signature length.

Returns: true on success.

Definition at line 982 of file fido2_storage.cpp.

References CDC_CURVE_ED25519, curve, ecc_slot_for_logical(), FIDO2_SIG_SIZE, g_storage, cdc::hal::getSecureElementInstance(), LOG_D, LOG_E, cdc::hal::OK, slot_logical_valid(), and TAG.

Referenced by ctap2_get_next_assertion(), ga_sign_assertion(), and u2f_authenticate().

◆ fido2_storage_slot_used()

bool fido2_storage_slot_used ( uint8_t slot )

Checks whether logical slot is occupied.

Parameters

slot	Logical slot index.

Returns: true if used.

Definition at line 478 of file fido2_storage.cpp.

References g_storage, and slot_logical_valid().

Referenced by fido2_factory_reset(), and fido2_get_credential_info().

◆ fido2_storage_verify_cred_id()

bool fido2_storage_verify_cred_id	(	uint8_t	slot,
		const uint8_t *	cred_id )

Verifies credential-id for logical slot.

Parameters

slot	Logical slot index.
cred_id	Credential ID bytes.

Returns: true if credential-id matches slot data.

Definition at line 664 of file fido2_storage.cpp.

References FIDO2_CRED_ID_LEN, and fido2_storage_get_cred_id().

◆ raw_sig_to_der()

uint8_t raw_sig_to_der	(	const uint8_t	raw_sig[FIDO2_SIG_SIZE],
		uint8_t *	der_sig )

static

Converts raw 64-byte ECDSA signature (R||S) to DER sequence format.

Converts a raw 64-byte ECDSA signature into DER encoding.

Parameters

raw_sig	Input raw signature buffer (R \|\| S).
der_sig	Output buffer that receives DER-encoded signature data.

Returns: Number of bytes written to der_sig.

Definition at line 294 of file fido2_storage.cpp.

References DER_TAG_SEQUENCE, encode_der_integer(), FIDO2_SIG_COMPONENT_SIZE, and FIDO2_SIG_SIZE.

Referenced by fido2_storage_sign(), and fido2_storage_sign_der().

◆ read_rmem_credential()

bool read_rmem_credential	(	uint8_t	logical_slot,
		fido2_stored_cred_t *	stored )

static

Internal helper functions for slot and cache management.

Reads a stored credential from R-Memory and validates its magic header.

Parameters

logical_slot	Logical credential slot index.
stored	Output structure receiving the stored credential payload.

Returns: true on successful read and validation, otherwise false.

Definition at line 189 of file fido2_storage.cpp.

References FIDO2_RMEM_MAGIC, FIDO2_RMEM_MAGIC_LEN, FIDO2_STORED_SIZE, cdc::hal::getSecureElementInstance(), cdc::hal::OK, and rmem_slot_for_logical().

Referenced by fido2_storage_get_cred_id(), fido2_storage_get_user(), fido2_storage_increment_sign_count(), and fido2_storage_init().

◆ rmem_count()

uint16_t rmem_count ( void )

static

Returns number of configured logical RMEM slots.

Returns: RMEM slot count.

Definition at line 146 of file fido2_storage.cpp.

References s_rmem_end, s_rmem_start, and slot_range_valid().

Referenced by fido2_storage_init().

◆ rmem_slot_for_logical()

uint16_t rmem_slot_for_logical ( uint8_t slot )

static

Maps logical slot to physical RMEM slot.

Parameters

slot	Logical slot index.

Returns: Physical RMEM slot.

Definition at line 175 of file fido2_storage.cpp.

References s_rmem_start, and slot_range_valid().

Referenced by erase_slot_data(), read_rmem_credential(), and write_rmem_credential().

◆ sha256()

void cdc::mod_fido2::sha256	(	const uint8_t *	data,
		size_t	len,
		uint8_t	out[32] )

inline

Definition at line 29 of file fido2_common.h.

◆ slot_logical_valid()

bool slot_logical_valid ( uint8_t slot )

static

Checks whether logical slot index is within range.

Parameters

slot	Logical slot index.

Returns: true if valid.

Definition at line 156 of file fido2_storage.cpp.

References ecc_count().

Referenced by fido2_storage_delete_credential(), fido2_storage_find_slot_by_cred_id(), fido2_storage_get_cred_id(), fido2_storage_get_credential(), fido2_storage_get_curve(), fido2_storage_get_pubkey(), fido2_storage_get_user(), fido2_storage_increment_sign_count(), fido2_storage_is_resident(), fido2_storage_sign(), fido2_storage_sign_der(), fido2_storage_sign_raw(), and fido2_storage_slot_used().

◆ slot_range_valid()

bool slot_range_valid ( void )

static

Validates slot-range configuration.

Returns: true if ranges are monotonic.

Definition at line 129 of file fido2_storage.cpp.

References s_ecc_end, s_ecc_start, s_rmem_end, and s_rmem_start.

Referenced by ecc_count(), fido2_storage_init(), rmem_count(), and rmem_slot_for_logical().

◆ update_cache_from_stored()

void update_cache_from_stored	(	uint8_t	slot,
		const fido2_stored_cred_t *	stored,
		bool	is_resident )

static

Updates cache entry from stored credential payload.

Updates in-memory cache entry from persisted credential structure.

Parameters

slot	Logical slot index.
stored	Stored credential payload.
is_resident	Resident-key flag.

Definition at line 220 of file fido2_storage.cpp.

References FIDO2_RP_ID_MAX_LEN, FIDO2_USER_NAME_MAX_LEN, and g_storage.

Referenced by fido2_storage_create_credential(), and fido2_storage_init().

◆ write_rmem_credential()

bool write_rmem_credential	(	uint8_t	logical_slot,
		const fido2_stored_cred_t *	stored )

static

Writes credential metadata to R-Memory after erasing the destination slot.

Parameters

logical_slot	Logical credential slot index.
stored	Credential payload to persist.

Returns: true if write succeeded, otherwise false.

Definition at line 314 of file fido2_storage.cpp.

References FIDO2_STORED_SIZE, cdc::hal::getSecureElementInstance(), LOG_E, cdc::hal::OK, rmem_slot_for_logical(), and TAG.

Referenced by fido2_storage_create_credential(), and fido2_storage_increment_sign_count().

Variable Documentation

◆ auth_counter

uint32_t auth_counter

Definition at line 61 of file fido2_storage.cpp.

◆ counter_loaded

bool counter_loaded

Definition at line 62 of file fido2_storage.cpp.

◆ cred_count

uint8_t cred_count

Definition at line 78 of file fido2_storage.cpp.

◆ cred_protect

uint8_t cred_protect

Definition at line 74 of file fido2_storage.cpp.

Referenced by ctap2_build_auth_data_for_cred(), and fido2_storage_create_credential().

◆ [struct]

struct { ... } creds[FIDO2_MAX_CREDENTIALS]

Referenced by ctap2_get_assertion(), and ga_find_credentials().

◆ curve

uint8_t curve

Definition at line 75 of file fido2_storage.cpp.

Referenced by cdc::mod_gpg::calculateFingerprintV4(), cdc::mod_gpg::calculateFingerprintV5(), cmd_generate_keypair(), cmd_get_data(), cdc::mod_gpg::cmd_gpg_generate(), cmd_internal_authenticate(), cmd_pso_cds(), cdc::mod_fido2::create_credential_and_respond(), ctap2_build_attested_cred(), cdc::mod_fido2::ctap2_make_credential(), cdc::hal::ISecureElement::eccGenerate(), cdc::hal::Tropic01Element::eccGenerate(), cdc::hal::ISecureElement::eccGetPublicKey(), cdc::hal::Tropic01Element::eccGetPublicKey(), cdc::hal::ISecureElement::eccImport(), cdc::hal::Tropic01Element::eccImport(), encode_pubkey_with_prefix(), fido2_storage_create_credential(), fido2_storage_get_pubkey(), fido2_storage_sign_raw(), generate_hardware_key(), get_algo_attr(), gpg_export_pubkey_pem(), gpg_generate_key(), host_ecc_generate(), key_fingerprint_generate(), se_ecc_key_generate(), se_ecc_key_read(), u2f_init_attestation(), cdc::core::verify_payload_signature(), verify_state_signature(), cdc::plugin_manager::w_host_ecc_generate(), cdc::plugin_manager::w_host_ecc_import(), and cdc::plugin_manager::w_host_ecc_pubkey().

◆ DER_INTEGER_MSB_MASK

uint8_t DER_INTEGER_MSB_MASK = 0x80

staticconstexpr

MSB mask used to detect when DER INTEGER needs a 0x00 padding byte.

Definition at line 256 of file fido2_storage.cpp.

Referenced by encode_der_integer().

◆ DER_TAG_INTEGER

uint8_t DER_TAG_INTEGER = 0x02

staticconstexpr

Definition at line 254 of file fido2_storage.cpp.

Referenced by encode_der_integer().

◆ DER_TAG_SEQUENCE

uint8_t DER_TAG_SEQUENCE = 0x30

staticconstexpr

DER ASN.1 tags used for ECDSA signature encoding.

Definition at line 253 of file fido2_storage.cpp.

Referenced by raw_sig_to_der().

◆ [struct]

◆ initialized

bool initialized

Definition at line 60 of file fido2_storage.cpp.

◆ resident

bool resident

Definition at line 73 of file fido2_storage.cpp.

◆ rp_id

char rp_id[FIDO2_RP_ID_MAX_LEN]

Definition at line 68 of file fido2_storage.cpp.

Referenced by client_pin_get_pin_uv_auth_token(), fido2_request_user_presence(), fido2_storage_create_credential(), cdc::mod_fido2::fido2_ui_user_presence_callback(), cdc::mod_fido2::is_browser_probe(), u2f_register(), and wait_for_user_presence().

◆ rp_id_hash

uint8_t rp_id_hash[32]

Definition at line 67 of file fido2_storage.cpp.

Referenced by build_authenticator_data(), cred_mgmt_find_creds_for_rp(), ctap2_build_auth_data_for_cred(), ctap2_cred_management(), fido2_find_credentials_by_rp(), fido2_get_credential_info(), fido2_storage_create_credential(), fido2_storage_find_by_rp(), fido2_storage_find_by_rp_resident(), and fido2_storage_find_by_rp_user().

◆ s_ecc_end

uint8_t s_ecc_end = 0

static

Definition at line 82 of file fido2_storage.cpp.

Referenced by ecc_count(), fido2_storage_ecc_end(), fido2_storage_set_slot_range(), and slot_range_valid().

◆ s_ecc_start

uint8_t s_ecc_start = 0

static

Definition at line 81 of file fido2_storage.cpp.

Referenced by ecc_count(), ecc_slot_for_logical(), fido2_storage_ecc_start(), fido2_storage_set_slot_range(), and slot_range_valid().

◆ s_rmem_end

uint16_t s_rmem_end = 0

static

Definition at line 84 of file fido2_storage.cpp.

Referenced by fido2_storage_rmem_end(), fido2_storage_set_slot_range(), rmem_count(), and slot_range_valid().

◆ s_rmem_start

uint16_t s_rmem_start = 0

static

Definition at line 83 of file fido2_storage.cpp.

Referenced by fido2_storage_rmem_start(), fido2_storage_set_slot_range(), rmem_count(), rmem_slot_for_logical(), and slot_range_valid().

◆ sign_count

uint32_t sign_count

Definition at line 72 of file fido2_storage.cpp.

Referenced by build_authenticator_data(), ctap2_get_assertion(), and ctap2_get_next_assertion().

◆ TAG

const char* TAG = "FIDO2"

static

Definition at line 18 of file fido2_storage.cpp.

◆ user_id

uint8_t user_id[FIDO2_USER_ID_MAX_LEN]

Definition at line 70 of file fido2_storage.cpp.

Referenced by fido2_storage_create_credential(), fido2_storage_find_by_rp_user(), fido2_storage_get_user(), gpg_set_pending_user_id(), cdc::mod_gpg::gpgCrossSignDigest(), cdc::mod_gpg::onWizardCurve(), and u2f_register().

◆ user_id_len

uint8_t user_id_len

Definition at line 71 of file fido2_storage.cpp.

Referenced by fido2_storage_create_credential(), fido2_storage_find_by_rp_user(), fido2_storage_get_credential(), and fido2_storage_get_user().

◆ user_name

char user_name[FIDO2_USER_NAME_MAX_LEN]

Definition at line 69 of file fido2_storage.cpp.

Referenced by fido2_request_user_presence(), fido2_storage_create_credential(), fido2_storage_get_user(), cdc::mod_fido2::fido2_ui_user_presence_callback(), and wait_for_user_presence().

◆ valid

bool valid

Definition at line 66 of file fido2_storage.cpp.

Referenced by checkBuildProfileAndWipeNvs(), cdc::mod_2fa::OathCodeView::onKey(), and cdc::ui::ListView::onKey().

Classes

Namespaces

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ FIDO2_FLAG_RESIDENT

◆ FIDO2_RMEM_MAGIC

◆ FIDO2_RMEM_MAGIC_LEN

◆ FIDO2_STORED_SIZE

◆ NVS_KEY_COUNTER

◆ NVS_NAMESPACE

Function Documentation

◆ ecc_count()

◆ ecc_slot_for_logical()

◆ encode_der_integer()

◆ erase_slot_data()

◆ fido2_storage_count()

◆ fido2_storage_counter_flush()

◆ fido2_storage_counter_get()

◆ fido2_storage_counter_increment()

◆ fido2_storage_counter_load()

◆ fido2_storage_create_credential()

◆ fido2_storage_delete_credential()

◆ fido2_storage_ecc_end()

◆ fido2_storage_ecc_start()

◆ fido2_storage_find_by_rp()

◆ fido2_storage_find_by_rp_resident()

◆ fido2_storage_find_by_rp_user()

◆ fido2_storage_find_free_slot()

◆ fido2_storage_find_slot_by_cred_id()

◆ fido2_storage_get_cred_id()

◆ fido2_storage_get_credential()

◆ fido2_storage_get_curve()

◆ fido2_storage_get_pubkey()

◆ fido2_storage_get_user()

◆ fido2_storage_increment_sign_count()

◆ fido2_storage_init()

◆ fido2_storage_is_resident()

◆ fido2_storage_rmem_end()

◆ fido2_storage_rmem_start()

◆ fido2_storage_set_slot_range()

◆ fido2_storage_sign()

◆ fido2_storage_sign_der()

◆ fido2_storage_sign_raw()

◆ fido2_storage_slot_used()

◆ fido2_storage_verify_cred_id()

◆ raw_sig_to_der()

◆ read_rmem_credential()

◆ rmem_count()

◆ rmem_slot_for_logical()

◆ sha256()

◆ slot_logical_valid()

◆ slot_range_valid()

◆ update_cache_from_stored()

◆ write_rmem_credential()

Variable Documentation

◆ auth_counter

◆ counter_loaded

◆ cred_count

◆ cred_protect

◆ [struct]

◆ curve

◆ DER_INTEGER_MSB_MASK

◆ DER_TAG_INTEGER

◆ DER_TAG_SEQUENCE

◆ [struct]

◆ initialized

◆ resident

◆ rp_id

◆ rp_id_hash

◆ s_ecc_end

◆ s_ecc_start

◆ s_rmem_end

◆ s_rmem_start

◆ sign_count

◆ TAG

◆ user_id

◆ user_id_len