feat(core): Propagate Optiga errors.

temp_ci_master
Andrew Kozlik 9 months ago committed by Andrew Kozlik
parent 240f4f56cd
commit 4c7979ae30

@ -23,6 +23,7 @@
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include "optiga_common.h"
#include "secbool.h"
#define OPTIGA_DEVICE_CERT_INDEX 1
@ -52,12 +53,12 @@ bool __wur optiga_read_cert(uint8_t index, uint8_t *cert, size_t max_cert_size,
bool __wur optiga_random_buffer(uint8_t *dest, size_t size);
bool __wur optiga_pin_set(OPTIGA_UI_PROGRESS ui_progress,
const uint8_t pin_secret[OPTIGA_PIN_SECRET_SIZE],
uint8_t out_secret[OPTIGA_PIN_SECRET_SIZE]);
int __wur optiga_pin_set(OPTIGA_UI_PROGRESS ui_progress,
const uint8_t pin_secret[OPTIGA_PIN_SECRET_SIZE],
uint8_t out_secret[OPTIGA_PIN_SECRET_SIZE]);
bool __wur optiga_pin_verify(OPTIGA_UI_PROGRESS ui_progress,
const uint8_t pin_secret[OPTIGA_PIN_SECRET_SIZE],
uint8_t out_secret[OPTIGA_PIN_SECRET_SIZE]);
int __wur optiga_pin_verify(OPTIGA_UI_PROGRESS ui_progress,
const uint8_t pin_secret[OPTIGA_PIN_SECRET_SIZE],
uint8_t out_secret[OPTIGA_PIN_SECRET_SIZE]);
#endif

@ -340,12 +340,12 @@ static bool optiga_pin_init_metadata(void) {
return true;
}
static bool optiga_pin_init_stretch(void) {
static int optiga_pin_init_stretch(void) {
// Generate a new key in OID_PIN_CMAC.
optiga_result res =
optiga_gen_sym_key(OPTIGA_AES_256, OPTIGA_KEY_USAGE_ENC, OID_PIN_CMAC);
if (res != OPTIGA_SUCCESS) {
return false;
return res;
}
// Generate a new key in OID_PIN_ECDH.
@ -355,14 +355,14 @@ static bool optiga_pin_init_stretch(void) {
optiga_gen_key_pair(OPTIGA_CURVE_P256, OPTIGA_KEY_USAGE_KEYAGREE,
OID_PIN_ECDH, public_key, sizeof(public_key), &size);
if (res != OPTIGA_SUCCESS) {
return false;
return res;
}
return true;
return OPTIGA_SUCCESS;
}
static bool optiga_pin_stretch_secret(OPTIGA_UI_PROGRESS ui_progress,
uint8_t secret[OPTIGA_PIN_SECRET_SIZE]) {
static int optiga_pin_stretch_secret(OPTIGA_UI_PROGRESS ui_progress,
uint8_t secret[OPTIGA_PIN_SECRET_SIZE]) {
// This step hardens the PIN verification process in case an attacker is able
// to extract the secret value of a data object in Optiga that has a
// particular configuration, but does not allow secret extraction for other
@ -399,7 +399,7 @@ static bool optiga_pin_stretch_secret(OPTIGA_UI_PROGRESS ui_progress,
memzero(buffer, sizeof(buffer));
memzero(result, sizeof(result));
memzero(&ctx, sizeof(ctx));
return false;
return res;
}
hmac_sha256_Update(&ctx, buffer, size);
@ -411,7 +411,7 @@ static bool optiga_pin_stretch_secret(OPTIGA_UI_PROGRESS ui_progress,
memzero(buffer, sizeof(buffer));
memzero(result, sizeof(result));
memzero(&ctx, sizeof(ctx));
return false;
return res;
}
hmac_sha256_Update(&ctx, buffer, size);
@ -424,7 +424,7 @@ static bool optiga_pin_stretch_secret(OPTIGA_UI_PROGRESS ui_progress,
memzero(buffer, sizeof(buffer));
memzero(result, sizeof(result));
memzero(&ctx, sizeof(ctx));
return false;
return -1;
}
res =
optiga_calc_ssec(OPTIGA_CURVE_P256, OID_PIN_ECDH, encoded_point,
@ -434,7 +434,7 @@ static bool optiga_pin_stretch_secret(OPTIGA_UI_PROGRESS ui_progress,
memzero(buffer, sizeof(buffer));
memzero(result, sizeof(result));
memzero(&ctx, sizeof(ctx));
return false;
return res;
}
hmac_sha256_Update(&ctx, buffer, size);
@ -448,15 +448,21 @@ static bool optiga_pin_stretch_secret(OPTIGA_UI_PROGRESS ui_progress,
memzero(buffer, sizeof(buffer));
memzero(result, sizeof(result));
memzero(&ctx, sizeof(ctx));
return true;
return OPTIGA_SUCCESS;
}
bool optiga_pin_set(OPTIGA_UI_PROGRESS ui_progress,
const uint8_t pin_secret[OPTIGA_PIN_SECRET_SIZE],
uint8_t out_secret[OPTIGA_PIN_SECRET_SIZE]) {
if (!optiga_pin_init_metadata() || !optiga_pin_init_stretch()) {
return false;
int optiga_pin_set(OPTIGA_UI_PROGRESS ui_progress,
const uint8_t pin_secret[OPTIGA_PIN_SECRET_SIZE],
uint8_t out_secret[OPTIGA_PIN_SECRET_SIZE]) {
if (!optiga_pin_init_metadata()) {
return -1;
}
optiga_result res = optiga_pin_init_stretch();
if (res != OPTIGA_SUCCESS) {
return res;
}
ui_progress(200);
// Process the PIN-derived secret using a one-way function before sending it
@ -469,16 +475,17 @@ bool optiga_pin_set(OPTIGA_UI_PROGRESS ui_progress,
// Combine the result with stretching secrets from the Optiga. This step
// ensures that if an attacker extracts the value of OID_STRETCHED_PIN, then
// it cannot be used to conduct an offline brute-force search for the PIN.
if (!optiga_pin_stretch_secret(ui_progress, stretched_pin)) {
res = optiga_pin_stretch_secret(ui_progress, stretched_pin);
if (res != OPTIGA_SUCCESS) {
memzero(stretched_pin, sizeof(stretched_pin));
return false;
return res;
}
// Generate and store the master secret / PIN counter reset key.
optiga_result res = optiga_get_random(out_secret, OPTIGA_PIN_SECRET_SIZE);
res = optiga_get_random(out_secret, OPTIGA_PIN_SECRET_SIZE);
if (res != OPTIGA_SUCCESS) {
memzero(stretched_pin, sizeof(stretched_pin));
return false;
return res;
}
random_xor(out_secret, OPTIGA_PIN_SECRET_SIZE);
@ -486,7 +493,7 @@ bool optiga_pin_set(OPTIGA_UI_PROGRESS ui_progress,
OPTIGA_PIN_SECRET_SIZE);
if (res != OPTIGA_SUCCESS) {
memzero(stretched_pin, sizeof(stretched_pin));
return false;
return res;
}
// Authorise using OID_PIN_SECRET so that we can write to OID_PIN_COUNTER and
@ -495,7 +502,7 @@ bool optiga_pin_set(OPTIGA_UI_PROGRESS ui_progress,
out_secret, OPTIGA_PIN_SECRET_SIZE);
if (res != OPTIGA_SUCCESS) {
memzero(stretched_pin, sizeof(stretched_pin));
return false;
return res;
}
// Set the stretched PIN.
@ -504,7 +511,7 @@ bool optiga_pin_set(OPTIGA_UI_PROGRESS ui_progress,
memzero(stretched_pin, sizeof(stretched_pin));
if (res != OPTIGA_SUCCESS) {
optiga_clear_auto_state(OID_PIN_SECRET);
return false;
return res;
}
// Initialize the PIN counter.
@ -512,7 +519,7 @@ bool optiga_pin_set(OPTIGA_UI_PROGRESS ui_progress,
sizeof(COUNTER_RESET));
optiga_clear_auto_state(OID_PIN_SECRET);
if (res != OPTIGA_SUCCESS) {
return false;
return res;
}
ui_progress(200);
@ -523,8 +530,9 @@ bool optiga_pin_set(OPTIGA_UI_PROGRESS ui_progress,
// offline brute-force search for the PIN.
hmac_sha256(pin_secret, OPTIGA_PIN_SECRET_SIZE, out_secret,
OPTIGA_PIN_SECRET_SIZE, out_secret);
if (!optiga_pin_stretch_secret(ui_progress, out_secret)) {
return false;
res = optiga_pin_stretch_secret(ui_progress, out_secret);
if (res != OPTIGA_SUCCESS) {
return res;
}
// Combine the stretched master secret with the PIN-derived secret to obtain
@ -544,30 +552,36 @@ bool optiga_pin_set(OPTIGA_UI_PROGRESS ui_progress,
// security of their device any more than if the Optiga was not integrated
// into the device in the first place.
return true;
return OPTIGA_SUCCESS;
}
bool optiga_pin_verify(OPTIGA_UI_PROGRESS ui_progress,
const uint8_t pin_secret[OPTIGA_PIN_SECRET_SIZE],
uint8_t out_secret[OPTIGA_PIN_SECRET_SIZE]) {
int optiga_pin_verify(OPTIGA_UI_PROGRESS ui_progress,
const uint8_t pin_secret[OPTIGA_PIN_SECRET_SIZE],
uint8_t out_secret[OPTIGA_PIN_SECRET_SIZE]) {
// Process the PIN-derived secret using a one-way function before sending it
// to the Optiga.
uint8_t stretched_pin[OPTIGA_PIN_SECRET_SIZE] = {0};
hmac_sha256(pin_secret, OPTIGA_PIN_SECRET_SIZE, NULL, 0, stretched_pin);
// Combine the result with stretching secrets from the Optiga.
if (!optiga_pin_stretch_secret(ui_progress, stretched_pin)) {
optiga_result res = optiga_pin_stretch_secret(ui_progress, stretched_pin);
if (res != OPTIGA_SUCCESS) {
memzero(stretched_pin, sizeof(stretched_pin));
return false;
return res;
}
// Authorise using OID_STRETCHED_PIN so that we can read from OID_PIN_SECRET.
optiga_result res =
optiga_set_auto_state(OPTIGA_OID_SESSION_CTX, OID_STRETCHED_PIN,
stretched_pin, sizeof(stretched_pin));
res = optiga_set_auto_state(OPTIGA_OID_SESSION_CTX, OID_STRETCHED_PIN,
stretched_pin, sizeof(stretched_pin));
memzero(stretched_pin, sizeof(stretched_pin));
if (res == OPTIGA_ERR_CMD) {
uint8_t error_code = 0;
optiga_get_error_code(&error_code);
return error_code + OPTIGA_COMMAND_ERROR_OFFSET;
}
if (res != OPTIGA_SUCCESS) {
return false;
return res;
}
// Read the master secret from OID_PIN_SECRET.
@ -575,8 +589,12 @@ bool optiga_pin_verify(OPTIGA_UI_PROGRESS ui_progress,
res = optiga_get_data_object(OID_PIN_SECRET, false, out_secret,
OPTIGA_PIN_SECRET_SIZE, &size);
optiga_clear_auto_state(OID_STRETCHED_PIN);
if (res != OPTIGA_SUCCESS || size != OPTIGA_PIN_SECRET_SIZE) {
return false;
if (res != OPTIGA_SUCCESS) {
return res;
}
if (size != OPTIGA_PIN_SECRET_SIZE) {
return OPTIGA_ERR_SIZE;
}
ui_progress(200);
@ -585,7 +603,7 @@ bool optiga_pin_verify(OPTIGA_UI_PROGRESS ui_progress,
res = optiga_set_auto_state(OPTIGA_OID_SESSION_CTX, OID_PIN_SECRET,
out_secret, OPTIGA_PIN_SECRET_SIZE);
if (res != OPTIGA_SUCCESS) {
return false;
return res;
}
// Reset the PIN counter.
@ -593,7 +611,7 @@ bool optiga_pin_verify(OPTIGA_UI_PROGRESS ui_progress,
sizeof(COUNTER_RESET));
optiga_clear_auto_state(OID_PIN_SECRET);
if (res != OPTIGA_SUCCESS) {
return false;
return res;
}
ui_progress(200);
@ -602,13 +620,14 @@ bool optiga_pin_verify(OPTIGA_UI_PROGRESS ui_progress,
// stretching secrets from the Optiga.
hmac_sha256(pin_secret, OPTIGA_PIN_SECRET_SIZE, out_secret,
OPTIGA_PIN_SECRET_SIZE, out_secret);
if (!optiga_pin_stretch_secret(ui_progress, out_secret)) {
return false;
res = optiga_pin_stretch_secret(ui_progress, out_secret);
if (res != OPTIGA_SUCCESS) {
return res;
}
// Combine the stretched master secret with the PIN-derived secret to derive
// the output secret.
hmac_sha256(pin_secret, OPTIGA_PIN_SECRET_SIZE, out_secret,
OPTIGA_PIN_SECRET_SIZE, out_secret);
return true;
return OPTIGA_SUCCESS;
}

@ -152,18 +152,18 @@ bool optiga_random_buffer(uint8_t *dest, size_t size) {
return true;
}
bool optiga_pin_set(OPTIGA_UI_PROGRESS ui_progress,
const uint8_t pin_secret[OPTIGA_PIN_SECRET_SIZE],
uint8_t out_secret[OPTIGA_PIN_SECRET_SIZE]) {
int optiga_pin_set(OPTIGA_UI_PROGRESS ui_progress,
const uint8_t pin_secret[OPTIGA_PIN_SECRET_SIZE],
uint8_t out_secret[OPTIGA_PIN_SECRET_SIZE]) {
memcpy(out_secret, pin_secret, OPTIGA_PIN_SECRET_SIZE);
ui_progress(OPTIGA_PIN_DERIVE_MS);
return true;
return OPTIGA_SUCCESS;
}
bool optiga_pin_verify(OPTIGA_UI_PROGRESS ui_progress,
const uint8_t pin_secret[OPTIGA_PIN_SECRET_SIZE],
uint8_t out_secret[OPTIGA_PIN_SECRET_SIZE]) {
int optiga_pin_verify(OPTIGA_UI_PROGRESS ui_progress,
const uint8_t pin_secret[OPTIGA_PIN_SECRET_SIZE],
uint8_t out_secret[OPTIGA_PIN_SECRET_SIZE]) {
memcpy(out_secret, pin_secret, OPTIGA_PIN_SECRET_SIZE);
ui_progress(OPTIGA_PIN_DERIVE_MS);
return true;
return OPTIGA_SUCCESS;
}

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