unsigned short btchip_apdu_get_random() {
unsigned char length = G_io_apdu_buffer[ISO_OFFSET_LC];
if (length == 0) {
length = MAX_LENGTH;
}
if (length > MAX_LENGTH) {
return BTCHIP_SW_INCORRECT_LENGTH;
}
cx_rng(G_io_apdu_buffer, length);
btchip_context_D.outLength = length;
return BTCHIP_SW_OK;
}
unsigned short btchip_apdu_get_trusted_input() {
unsigned char apduLength;
unsigned char dataOffset = 0;
unsigned char trustedInputSignature[32];
cx_sha256_t hash;
apduLength = G_io_apdu_buffer[ISO_OFFSET_LC];
SB_CHECK(N_btchip.bkp.config.operationMode);
switch (SB_GET(N_btchip.bkp.config.operationMode)) {
case BTCHIP_MODE_WALLET:
case BTCHIP_MODE_RELAXED_WALLET:
case BTCHIP_MODE_SERVER:
break;
default:
return BTCHIP_SW_CONDITIONS_OF_USE_NOT_SATISFIED;
}
if (G_io_apdu_buffer[ISO_OFFSET_P1] == GET_TRUSTED_INPUT_P1_FIRST) {
// Initialize
btchip_context_D.transactionTargetInput =
btchip_read_u32(G_io_apdu_buffer + ISO_OFFSET_CDATA, 1, 0);
btchip_context_D.transactionContext.transactionState =
BTCHIP_TRANSACTION_NONE;
btchip_context_D.trustedInputProcessed = 0;
btchip_context_D.transactionContext.consumeP2SH = 0;
btchip_set_check_internal_structure_integrity(1);
dataOffset = 4;
btchip_context_D.transactionHashOption = TRANSACTION_HASH_FULL;
btchip_context_D.usingSegwit = 0;
} else if (G_io_apdu_buffer[ISO_OFFSET_P1] != GET_TRUSTED_INPUT_P1_NEXT) {
return BTCHIP_SW_INCORRECT_P1_P2;
}
if (G_io_apdu_buffer[ISO_OFFSET_P2] != 0x00) {
return BTCHIP_SW_INCORRECT_P1_P2;
}
btchip_context_D.transactionBufferPointer =
G_io_apdu_buffer + ISO_OFFSET_CDATA + dataOffset;
btchip_context_D.transactionDataRemaining = apduLength - dataOffset;
transaction_parse(PARSE_MODE_TRUSTED_INPUT);
if (btchip_context_D.transactionContext.transactionState ==
BTCHIP_TRANSACTION_PARSED) {
unsigned char targetHash[32];
btchip_context_D.transactionContext.transactionState =
BTCHIP_TRANSACTION_NONE;
btchip_set_check_internal_structure_integrity(1);
if (!btchip_context_D.trustedInputProcessed) {
// Output was not found
return BTCHIP_SW_INCORRECT_DATA;
}
cx_hash(&btchip_context_D.transactionHashFull.sha256.header, CX_LAST,
(unsigned char *)NULL, 0, targetHash, 32);
// Otherwise prepare
cx_rng(G_io_apdu_buffer, 8);
G_io_apdu_buffer[0] = MAGIC_TRUSTED_INPUT;
G_io_apdu_buffer[1] = 0x00;
cx_sha256_init(&hash);
cx_hash(&hash.header, CX_LAST, targetHash, 32, G_io_apdu_buffer + 4, 32);
btchip_write_u32_le(G_io_apdu_buffer + 4 + 32,
btchip_context_D.transactionTargetInput);
os_memmove(G_io_apdu_buffer + 4 + 32 + 4,
btchip_context_D.transactionContext.transactionAmount, 8);
cx_hmac_sha256(N_btchip.bkp.trustedinput_key,
sizeof(N_btchip.bkp.trustedinput_key), G_io_apdu_buffer,
TRUSTEDINPUT_SIZE, trustedInputSignature, 32);
os_memmove(G_io_apdu_buffer + TRUSTEDINPUT_SIZE, trustedInputSignature,
8);
btchip_context_D.outLength = 0x38;
}
return BTCHIP_SW_OK;
}
