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Moving from U2F to CTAP1.

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Signed-off-by: Pol Henarejos <pol.henarejos@cttc.es>
This commit is contained in:
Pol Henarejos
2022-09-08 17:35:56 +02:00
parent 7ae80ab688
commit 73f88b6882
6 changed files with 39 additions and 39 deletions
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30
src/fido/cmd_authenticate.c
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@@ -18,19 +18,19 @@
#include "fido.h"
#include "hsm.h"
#include "apdu.h"
#include "u2f.h"
#include "ctap.h"
#include "mbedtls/ecdsa.h"
#include "random.h"
#include "files.h"
int cmd_authenticate() {
U2F_AUTHENTICATE_REQ *req = (U2F_AUTHENTICATE_REQ *)apdu.data;
U2F_AUTHENTICATE_RESP *resp = (U2F_AUTHENTICATE_RESP *)res_APDU;
CTAP_AUTHENTICATE_REQ *req = (CTAP_AUTHENTICATE_REQ *)apdu.data;
CTAP_AUTHENTICATE_RESP *resp = (CTAP_AUTHENTICATE_RESP *)res_APDU;
if (scan_files() != CCID_OK)
return SW_EXEC_ERROR();
if (req->keyHandleLen != KEY_HANDLE_LEN)
return SW_WRONG_DATA();
if (P1(apdu) == U2F_AUTH_ENFORCE && wait_button_pressed() == true)
if (P1(apdu) == CTAP_AUTH_ENFORCE && wait_button_pressed() == true)
return SW_CONDITIONS_NOT_SATISFIED();
mbedtls_ecdsa_context key;
@@ -40,7 +40,7 @@ int cmd_authenticate() {
mbedtls_ecdsa_free(&key);
return SW_EXEC_ERROR();
}
if (P1(apdu) == U2F_AUTH_CHECK_ONLY) {
if (P1(apdu) == CTAP_AUTH_CHECK_ONLY) {
for (int i = 0; i < KEY_PATH_ENTRIES; i++) {
uint32_t k = *(uint32_t *)&req->keyHandle[i*sizeof(uint32_t)];
if (!(k & 0x80000000)) {
@@ -53,9 +53,9 @@ int cmd_authenticate() {
mbedtls_ecdsa_free(&key);
if (ret != 0)
return SW_WRONG_DATA();
uint8_t key_base[U2F_APPID_SIZE + KEY_PATH_LEN];
memcpy(key_base, req->appId, U2F_APPID_SIZE);
memcpy(key_base + U2F_APPID_SIZE, req->keyHandle, KEY_PATH_LEN);
uint8_t key_base[CTAP_APPID_SIZE + KEY_PATH_LEN];
memcpy(key_base, req->appId, CTAP_APPID_SIZE);
memcpy(key_base + CTAP_APPID_SIZE, req->keyHandle, KEY_PATH_LEN);
ret = mbedtls_md_hmac(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), d, 32, key_base, sizeof(key_base), hmac);
mbedtls_platform_zeroize(d, sizeof(d));
if (memcmp(req->keyHandle + KEY_PATH_LEN, hmac, sizeof(hmac)) != 0)
@@ -63,24 +63,24 @@ int cmd_authenticate() {
return SW_CONDITIONS_NOT_SATISFIED();
}
resp->flags = 0;
resp->flags |= P1(apdu) == U2F_AUTH_ENFORCE ? U2F_AUTH_FLAG_TUP : 0x0;
resp->flags |= P1(apdu) == CTAP_AUTH_ENFORCE ? CTAP_AUTH_FLAG_TUP : 0x0;
uint32_t ctr = *(uint32_t *)file_get_data(ef_counter);
resp->ctr[0] = ctr >> 24;
resp->ctr[1] = ctr >> 16;
resp->ctr[2] = ctr >> 8;
resp->ctr[3] = ctr & 0xff;
uint8_t hash[32], sig_base[U2F_APPID_SIZE + 1 + 4 + U2F_CHAL_SIZE];
memcpy(sig_base, req->appId, U2F_APPID_SIZE);
memcpy(sig_base+U2F_APPID_SIZE, &resp->flags, sizeof(uint8_t));
memcpy(sig_base + U2F_APPID_SIZE + 1, resp->ctr, 4);
memcpy(sig_base + U2F_APPID_SIZE + 1 + 4, req->chal, U2F_CHAL_SIZE);
uint8_t hash[32], sig_base[CTAP_APPID_SIZE + 1 + 4 + CTAP_CHAL_SIZE];
memcpy(sig_base, req->appId, CTAP_APPID_SIZE);
memcpy(sig_base+CTAP_APPID_SIZE, &resp->flags, sizeof(uint8_t));
memcpy(sig_base + CTAP_APPID_SIZE + 1, resp->ctr, 4);
memcpy(sig_base + CTAP_APPID_SIZE + 1 + 4, req->chal, CTAP_CHAL_SIZE);
ret = mbedtls_md(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), sig_base, sizeof(sig_base), hash);
if (ret != 0) {
mbedtls_ecdsa_free(&key);
return SW_EXEC_ERROR();
}
size_t olen = 0;
ret = mbedtls_ecdsa_write_signature(&key, MBEDTLS_MD_SHA256, hash, 32, (uint8_t *)resp->sig, U2F_MAX_EC_SIG_SIZE, &olen, random_gen, NULL);
ret = mbedtls_ecdsa_write_signature(&key, MBEDTLS_MD_SHA256, hash, 32, (uint8_t *)resp->sig, CTAP_MAX_EC_SIG_SIZE, &olen, random_gen, NULL);
mbedtls_ecdsa_free(&key);
if (ret != 0)
return SW_EXEC_ERROR();