fsm: input messages are no longer confidential

firmware/fsm.h

@@ -73,7 +73,7 @@ void fsm_msgSignMessage(const SignMessage *msg);
 void fsm_msgVerifyMessage(const VerifyMessage *msg);
 
 // crypto
-void fsm_msgCipherKeyValue(CipherKeyValue *msg);    // not const because we mutate msg->iv
+void fsm_msgCipherKeyValue(const CipherKeyValue *msg);
 void fsm_msgSignIdentity(const SignIdentity *msg);
 void fsm_msgGetECDHSessionKey(const GetECDHSessionKey *msg);
 void fsm_msgCosiCommit(const CosiCommit *msg);
@@ -92,7 +92,7 @@ void fsm_msgDebugLinkFlashErase(const DebugLinkFlashErase *msg);
 // ethereum
 void fsm_msgEthereumGetAddress(const EthereumGetAddress *msg);
 void fsm_msgEthereumGetPublicKey(const EthereumGetPublicKey *msg);
-void fsm_msgEthereumSignTx(EthereumSignTx *msg);  // not const because we mutate transaction
+void fsm_msgEthereumSignTx(EthereumSignTx *msg);  // not const because we mutate transaction during validation
 void fsm_msgEthereumTxAck(const EthereumTxAck *msg);
 void fsm_msgEthereumSignMessage(const EthereumSignMessage *msg);
 void fsm_msgEthereumVerifyMessage(const EthereumVerifyMessage *msg);
@@ -102,7 +102,7 @@ void fsm_msgLiskGetAddress(const LiskGetAddress *msg);
 void fsm_msgLiskGetPublicKey(const LiskGetPublicKey *msg);
 void fsm_msgLiskSignMessage(const LiskSignMessage *msg);
 void fsm_msgLiskVerifyMessage(const LiskVerifyMessage *msg);
-void fsm_msgLiskSignTx(LiskSignTx *msg);  // // not const because we mutate transaction
+void fsm_msgLiskSignTx(LiskSignTx *msg);  // not const because we mutate transaction during validation
 
 // nem
 void fsm_msgNEMGetAddress(NEMGetAddress *msg);          // not const because we mutate msg->network

firmware/fsm_msg_crypto.h

@@ -17,7 +17,7 @@
  * along with this library.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-void fsm_msgCipherKeyValue(CipherKeyValue *msg)
+void fsm_msgCipherKeyValue(const CipherKeyValue *msg)
 {
 	CHECK_INITIALIZED
 
@@ -49,15 +49,20 @@ void fsm_msgCipherKeyValue(CipherKeyValue *msg)
 
 	hmac_sha512(node->private_key, 32, data, strlen((char *)data), data);
 
+	if (msg->iv.size == 16) {
+		// override iv if provided
+		memcpy(data + 32, msg->iv.bytes, 16);
+	}
+
 	RESP_INIT(CipheredKeyValue);
 	if (encrypt) {
 		aes_encrypt_ctx ctx;
 		aes_encrypt_key256(data, &ctx);
-		aes_cbc_encrypt(msg->value.bytes, resp->value.bytes, msg->value.size, ((msg->iv.size == 16) ? (msg->iv.bytes) : (data + 32)), &ctx);
+		aes_cbc_encrypt(msg->value.bytes, resp->value.bytes, msg->value.size, data + 32, &ctx);
 	} else {
 		aes_decrypt_ctx ctx;
 		aes_decrypt_key256(data, &ctx);
-		aes_cbc_decrypt(msg->value.bytes, resp->value.bytes, msg->value.size, ((msg->iv.size == 16) ? (msg->iv.bytes) : (data + 32)), &ctx);
+		aes_cbc_decrypt(msg->value.bytes, resp->value.bytes, msg->value.size, data + 32, &ctx);
 	}
 	resp->has_value = true;
 	resp->value.size = msg->value.size;

firmware/messages.c

@@ -36,7 +36,7 @@ struct MessagesMap_t {
 	char dir; 	// i = in, o = out
 	uint16_t msg_id;
 	const pb_field_t *fields;
-	void (*process_func)(void *ptr);
+	void (*process_func)(const void *ptr);
 };
 
 static const struct MessagesMap_t MessagesMap[] = {
@@ -222,7 +222,7 @@ enum {
 
 void msg_process(char type, uint16_t msg_id, const pb_field_t *fields, uint8_t *msg_raw, uint32_t msg_size)
 {
-	static CONFIDENTIAL uint8_t msg_data[MSG_IN_SIZE];
+	static uint8_t msg_data[MSG_IN_SIZE];
 	memzero(msg_data, sizeof(msg_data));
 	pb_istream_t stream = pb_istream_from_buffer(msg_raw, msg_size);
 	bool status = pb_decode(&stream, fields, msg_data);
@@ -236,7 +236,7 @@ void msg_process(char type, uint16_t msg_id, const pb_field_t *fields, uint8_t *
 void msg_read_common(char type, const uint8_t *buf, uint32_t len)
 {
 	static char read_state = READSTATE_IDLE;
-	static CONFIDENTIAL uint8_t msg_in[MSG_IN_SIZE];
+	static uint8_t msg_in[MSG_IN_SIZE];
 	static uint16_t msg_id = 0xFFFF;
 	static uint32_t msg_size = 0;
 	static uint32_t msg_pos = 0;

firmware/protob/messages_map.py

@@ -48,7 +48,7 @@ def handle_message(fh, fl, skipped, message, extension):
         return
 
     if direction == "i":
-        process_func = "(void (*)(void *)) fsm_msg%s" % short_name
+        process_func = "(void (*)(const void *))fsm_msg%s" % short_name
     else:
         process_func = "0"