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Extending DKEK and key storage to key domains.

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Signed-off-by: Pol Henarejos <pol.henarejos@cttc.es>
This commit is contained in:
Pol Henarejos
2022-05-24 00:29:19 +02:00
parent 7b5cb48dcc
commit 89d40b7c94
3 changed files with 132 additions and 102 deletions
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135
src/hsm/dkek.c
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@@ -29,114 +29,121 @@
#include "mbedtls/ecdsa.h"
#include "files.h"
static uint8_t dkek[IV_SIZE+32];
static uint8_t tmp_dkek[32];
extern bool has_session_pin;
extern uint8_t session_pin[32];
int load_dkek() {
int load_dkek(uint8_t id, uint8_t *dkek) {
if (has_session_pin == false)
return CCID_NO_LOGIN;
file_t *tf = search_dynamic_file(EF_DKEK);
file_t *tf = search_dynamic_file(EF_DKEK+id);
if (!tf)
return CCID_ERR_FILE_NOT_FOUND;
memcpy(dkek, file_read(tf->data+sizeof(uint16_t)), IV_SIZE+32);
int ret = aes_decrypt_cfb_256(session_pin, dkek, dkek+IV_SIZE, 32);
memcpy(dkek, file_read(tf->data+sizeof(uint16_t)), DKEK_SIZE);
int ret = aes_decrypt_cfb_256(session_pin, DKEK_IV(dkek), DKEK_KEY(dkek), DKEK_KEY_SIZE);
if (ret != 0)
return CCID_EXEC_ERROR;
return CCID_OK;
}
void release_dkek() {
memset(dkek, 0, sizeof(dkek));
void release_dkek(uint8_t *dkek) {
memset(dkek, 0, DKEK_SIZE);
}
void init_dkek() {
release_dkek();
memset(tmp_dkek, 0, sizeof(tmp_dkek));
}
int store_dkek_key() {
aes_encrypt_cfb_256(session_pin, dkek, dkek+IV_SIZE, 32);
file_t *tf = search_dynamic_file(EF_DKEK);
int store_dkek_key(uint8_t id, uint8_t *dkek) {
file_t *tf = search_dynamic_file(EF_DKEK+id);
if (!tf)
return CCID_ERR_FILE_NOT_FOUND;
flash_write_data_to_file(tf, dkek, sizeof(dkek));
aes_encrypt_cfb_256(session_pin, DKEK_IV(dkek), DKEK_KEY(dkek), DKEK_KEY_SIZE);
flash_write_data_to_file(tf, dkek, DKEK_SIZE);
low_flash_available();
release_dkek();
release_dkek(dkek);
return CCID_OK;
}
int save_dkek_key(const uint8_t *key) {
int save_dkek_key(uint8_t id, const uint8_t *key) {
uint8_t dkek[DKEK_SIZE];
const uint8_t *iv = random_bytes_get(32);
memcpy(dkek, iv, IV_SIZE);
if (!key)
key = tmp_dkek;
memcpy(dkek+IV_SIZE, key, 32);
return store_dkek_key();
memcpy(dkek, iv, DKEK_IV_SIZE);
if (!key) {
file_t *tf = search_dynamic_file(EF_DKEK+id);
if (!tf)
return CCID_ERR_FILE_NOT_FOUND;
memcpy(DKEK_KEY(dkek), file_read(tf->data+sizeof(uint16_t)), DKEK_KEY_SIZE);
}
else
memcpy(DKEK_KEY(dkek), key, DKEK_KEY_SIZE);
return store_dkek_key(id, dkek);
}
void import_dkek_share(const uint8_t *share) {
for (int i = 0; i < 32; i++)
int import_dkek_share(uint8_t id, const uint8_t *share) {
uint8_t tmp_dkek[DKEK_KEY_SIZE];
file_t *tf = search_dynamic_file(EF_DKEK+id);
if (!tf)
return CCID_ERR_FILE_NOT_FOUND;
memset(tmp_dkek, 0, sizeof(tmp_dkek));
if (tf->data && file_read_uint16(tf->data) == DKEK_KEY_SIZE)
memcpy(tmp_dkek, file_read(tf->data+sizeof(uint16_t)),DKEK_KEY_SIZE);
for (int i = 0; i < DKEK_KEY_SIZE; i++)
tmp_dkek[i] ^= share[i];
flash_write_data_to_file(tf, tmp_dkek, DKEK_KEY_SIZE);
low_flash_available();
return CCID_OK;
}
int dkek_kcv(uint8_t *kcv) { //kcv 8 bytes
uint8_t hsh[32];
int r = load_dkek();
int dkek_kcv(uint8_t id, uint8_t *kcv) { //kcv 8 bytes
uint8_t hsh[32], dkek[DKEK_SIZE];
int r = load_dkek(id, dkek);
if (r != CCID_OK)
return r;
hash256(dkek+IV_SIZE, 32, hsh);
release_dkek();
hash256(DKEK_KEY(dkek), DKEK_KEY_SIZE, hsh);
release_dkek(dkek);
memcpy(kcv, hsh, 8);
return CCID_OK;
}
int dkek_kenc(uint8_t *kenc) { //kenc 32 bytes
uint8_t buf[32+4];
int r = load_dkek();
int dkek_kenc(uint8_t id, uint8_t *kenc) { //kenc 32 bytes
uint8_t dkek[DKEK_SIZE+4];
int r = load_dkek(id, dkek);
if (r != CCID_OK)
return r;
memcpy(buf, dkek+IV_SIZE, 32);
release_dkek();
memcpy(buf+32, "\x0\x0\x0\x1", 4);
hash256(buf, sizeof(buf), kenc);
memset(buf, 0, sizeof(buf));
memcpy(DKEK_KEY(dkek)+DKEK_KEY_SIZE, "\x0\x0\x0\x1", 4);
hash256(DKEK_KEY(dkek), DKEK_KEY_SIZE+4, kenc);
release_dkek(dkek);
return CCID_OK;
}
int dkek_kmac(uint8_t *kmac) { //kmac 32 bytes
uint8_t buf[32+4];
int r = load_dkek();
int dkek_kmac(uint8_t id, uint8_t *kmac) { //kmac 32 bytes
uint8_t dkek[DKEK_SIZE+4];
int r = load_dkek(id, dkek);
if (r != CCID_OK)
return r;
memcpy(buf, dkek+IV_SIZE, 32);
release_dkek();
memcpy(buf+32, "\x0\x0\x0\x2", 4);
hash256(buf, sizeof(buf), kmac);
memset(buf, 0, sizeof(buf));
memcpy(DKEK_KEY(dkek)+DKEK_KEY_SIZE, "\x0\x0\x0\x2", 4);
hash256(DKEK_KEY(dkek), DKEK_KEY_SIZE+4, kmac);
release_dkek(dkek);
return CCID_OK;
}
int dkek_encrypt(uint8_t *data, size_t len) {
int dkek_encrypt(uint8_t id, uint8_t *data, size_t len) {
int r;
if ((r = load_dkek()) != CCID_OK)
uint8_t dkek[DKEK_SIZE+4];
if ((r = load_dkek(id, dkek)) != CCID_OK)
return r;
r = aes_encrypt_cfb_256(dkek+IV_SIZE, dkek, data, len);
release_dkek();
r = aes_encrypt_cfb_256(DKEK_KEY(dkek), DKEK_IV(dkek), data, len);
release_dkek(dkek);
return r;
}
int dkek_decrypt(uint8_t *data, size_t len) {
int dkek_decrypt(uint8_t id, uint8_t *data, size_t len) {
int r;
if ((r = load_dkek()) != CCID_OK)
uint8_t dkek[DKEK_SIZE+4];
if ((r = load_dkek(id, dkek)) != CCID_OK)
return r;
r = aes_decrypt_cfb_256(dkek+IV_SIZE, dkek, data, len);
release_dkek();
r = aes_decrypt_cfb_256(DKEK_KEY(dkek), DKEK_IV(dkek), data, len);
release_dkek(dkek);
return r;
}
int dkek_encode_key(void *key_ctx, int key_type, uint8_t *out, size_t *out_len) {
int dkek_encode_key(uint8_t id, void *key_ctx, int key_type, uint8_t *out, size_t *out_len) {
if (!(key_type & HSM_KEY_RSA) && !(key_type & HSM_KEY_EC) && !(key_type & HSM_KEY_AES))
return CCID_WRONG_DATA;
@@ -149,15 +156,15 @@ int dkek_encode_key(void *key_ctx, int key_type, uint8_t *out, size_t *out_len)
uint8_t allowed_len = 0;
uint8_t kenc[32];
memset(kenc, 0, sizeof(kenc));
dkek_kenc(kenc);
dkek_kenc(id, kenc);
uint8_t kcv[8];
memset(kcv, 0, sizeof(kcv));
dkek_kcv(kcv);
dkek_kcv(id, kcv);
uint8_t kmac[32];
memset(kmac, 0, sizeof(kmac));
dkek_kmac(kmac);
dkek_kmac(id, kmac);
if (key_type & HSM_KEY_AES) {
if (key_type & HSM_KEY_AES_128)
@@ -290,18 +297,18 @@ int dkek_type_key(const uint8_t *in) {
return 0x0;
}
int dkek_decode_key(void *key_ctx, const uint8_t *in, size_t in_len, int *key_size_out) {
int dkek_decode_key(uint8_t id, void *key_ctx, const uint8_t *in, size_t in_len, int *key_size_out) {
uint8_t kcv[8];
memset(kcv, 0, sizeof(kcv));
dkek_kcv(kcv);
dkek_kcv(id, kcv);
uint8_t kmac[32];
memset(kmac, 0, sizeof(kmac));
dkek_kmac(kmac);
dkek_kmac(id, kmac);
uint8_t kenc[32];
memset(kenc, 0, sizeof(kenc));
dkek_kenc(kenc);
dkek_kenc(id, kenc);
if (memcmp(kcv, in, 8) != 0)
return CCID_WRONG_DKEK;
@@ -472,4 +479,4 @@ int dkek_decode_key(void *key_ctx, const uint8_t *in, size_t in_len, int *key_si
memcpy(key_ctx, kb+ofs, key_size);
}
return CCID_OK;
}
}