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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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2
pico-hsm-sdk

Submodule pico-hsm-sdk updated: 7491021102...867d4637ee

30
src/fido/cmd_authenticate.c
View File

@@ -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();

28
src/fido/cmd_register.c
View File

@@ -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_register() {
U2F_REGISTER_REQ *req = (U2F_REGISTER_REQ *)apdu.data;
U2F_REGISTER_RESP *resp = (U2F_REGISTER_RESP *)res_APDU;
resp->registerId = U2F_REGISTER_ID;
CTAP_REGISTER_REQ *req = (CTAP_REGISTER_REQ *)apdu.data;
CTAP_REGISTER_RESP *resp = (CTAP_REGISTER_RESP *)res_APDU;
resp->registerId = CTAP_REGISTER_ID;
resp->keyHandleLen = KEY_HANDLE_LEN;
if (scan_files() != CCID_OK)
return SW_EXEC_ERROR();
if (apdu.nc != U2F_APPID_SIZE + U2F_CHAL_SIZE)
if (apdu.nc != CTAP_APPID_SIZE + CTAP_CHAL_SIZE)
return SW_WRONG_LENGTH();
if (wait_button_pressed() == true)
return SW_CONDITIONS_NOT_SATISFIED();
@@ -42,19 +42,19 @@ int cmd_register() {
return SW_EXEC_ERROR();
}
size_t olen = 0;
ret = mbedtls_ecp_point_write_binary(&key.grp, &key.Q, MBEDTLS_ECP_PF_UNCOMPRESSED, &olen, (uint8_t *)&resp->pubKey, U2F_EC_POINT_SIZE);
ret = mbedtls_ecp_point_write_binary(&key.grp, &key.Q, MBEDTLS_ECP_PF_UNCOMPRESSED, &olen, (uint8_t *)&resp->pubKey, CTAP_EC_POINT_SIZE);
mbedtls_ecdsa_free(&key);
if (ret != 0) {
return SW_EXEC_ERROR();
}
size_t ef_certdev_size = file_get_size(ef_certdev);
memcpy(resp->keyHandleCertSig + KEY_HANDLE_LEN, file_get_data(ef_certdev), ef_certdev_size);
uint8_t hash[32], sign_base[1 + U2F_APPID_SIZE + U2F_CHAL_SIZE + KEY_HANDLE_LEN + U2F_EC_POINT_SIZE];
sign_base[0] = U2F_REGISTER_HASH_ID;
memcpy(sign_base + 1, req->appId, U2F_APPID_SIZE);
memcpy(sign_base + 1 + U2F_APPID_SIZE, req->chal, U2F_CHAL_SIZE);
memcpy(sign_base + 1 + U2F_APPID_SIZE + U2F_CHAL_SIZE, resp->keyHandleCertSig, KEY_HANDLE_LEN);
memcpy(sign_base + 1 + U2F_APPID_SIZE + U2F_CHAL_SIZE + KEY_HANDLE_LEN, (uint8_t *)&resp->pubKey, U2F_EC_POINT_SIZE);
uint8_t hash[32], sign_base[1 + CTAP_APPID_SIZE + CTAP_CHAL_SIZE + KEY_HANDLE_LEN + CTAP_EC_POINT_SIZE];
sign_base[0] = CTAP_REGISTER_HASH_ID;
memcpy(sign_base + 1, req->appId, CTAP_APPID_SIZE);
memcpy(sign_base + 1 + CTAP_APPID_SIZE, req->chal, CTAP_CHAL_SIZE);
memcpy(sign_base + 1 + CTAP_APPID_SIZE + CTAP_CHAL_SIZE, resp->keyHandleCertSig, KEY_HANDLE_LEN);
memcpy(sign_base + 1 + CTAP_APPID_SIZE + CTAP_CHAL_SIZE + KEY_HANDLE_LEN, (uint8_t *)&resp->pubKey, CTAP_EC_POINT_SIZE);
ret = mbedtls_md(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), sign_base, sizeof(sign_base), hash);
if (ret != 0)
return SW_EXEC_ERROR();
@@ -64,11 +64,11 @@ int cmd_register() {
mbedtls_ecdsa_free(&key);
return SW_EXEC_ERROR();
}
ret = mbedtls_ecdsa_write_signature(&key, MBEDTLS_MD_SHA256, hash, 32, (uint8_t *)resp->keyHandleCertSig + KEY_HANDLE_LEN + ef_certdev_size, U2F_MAX_EC_SIG_SIZE, &olen, random_gen, NULL);
ret = mbedtls_ecdsa_write_signature(&key, MBEDTLS_MD_SHA256, hash, 32, (uint8_t *)resp->keyHandleCertSig + KEY_HANDLE_LEN + ef_certdev_size, CTAP_MAX_EC_SIG_SIZE, &olen, random_gen, NULL);
mbedtls_ecdsa_free(&key);
if (ret != 0)
return SW_EXEC_ERROR();
res_APDU_size = sizeof(U2F_REGISTER_RESP) - sizeof(resp->keyHandleCertSig) + KEY_HANDLE_LEN + ef_certdev_size + olen;
res_APDU_size = sizeof(CTAP_REGISTER_RESP) - sizeof(resp->keyHandleCertSig) + KEY_HANDLE_LEN + ef_certdev_size + olen;
DEBUG_PAYLOAD(res_APDU, res_APDU_size);
return SW_OK();
}

2
src/fido/cmd_version.c
View File

@@ -20,7 +20,7 @@
#include "hsm.h"
int cmd_version() {
memcpy(res_APDU, "U2F_V2", strlen("U2F_V2"));
memcpy(res_APDU, "CTAP_V2", strlen("U2F_V2"));
res_APDU_size = strlen("U2F_V2");
return SW_OK();
}

14
src/fido/fido.c
View File

@@ -19,7 +19,7 @@
#include "fido.h"
#include "hsm.h"
#include "apdu.h"
#include "u2f.h"
#include "ctap.h"
#include "files.h"
#include "file.h"
#include "usb.h"
@@ -112,9 +112,9 @@ int derive_key(const uint8_t *app_id, bool new_key, uint8_t *key_handle, mbedtls
}
}
if (new_key == true) {
uint8_t key_base[U2F_APPID_SIZE + KEY_PATH_LEN];
memcpy(key_base, app_id, U2F_APPID_SIZE);
memcpy(key_base + U2F_APPID_SIZE, key_handle, KEY_PATH_LEN);
uint8_t key_base[CTAP_APPID_SIZE + KEY_PATH_LEN];
memcpy(key_base, app_id, CTAP_APPID_SIZE);
memcpy(key_base + CTAP_APPID_SIZE, key_handle, KEY_PATH_LEN);
if ((r = mbedtls_md_hmac(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), outk, 32, key_base, sizeof(key_base), key_handle + 32)) != 0)
{
mbedtls_platform_zeroize(outk, sizeof(outk));
@@ -225,9 +225,9 @@ extern int cmd_authenticate();
extern int cmd_version();
static const cmd_t cmds[] = {
{ U2F_REGISTER, cmd_register },
{ U2F_AUTHENTICATE, cmd_authenticate },
{ U2F_VERSION, cmd_version },
{ CTAP_REGISTER, cmd_register },
{ CTAP_AUTHENTICATE, cmd_authenticate },
{ CTAP_VERSION, cmd_version },
{ 0x00, 0x0}
};

2
src/fido/fido.h
View File

@@ -23,7 +23,7 @@
#include "common.h"
#include "mbedtls/ecdsa.h"
#define U2F_PUBKEY_LEN (65)
#define CTAP_PUBKEY_LEN (65)
#define KEY_PATH_LEN (32)
#define KEY_PATH_ENTRIES (KEY_PATH_LEN / sizeof(uint32_t))
#define SHA256_DIGEST_LENGTH (32)