RSK checksum address encoding (#376)

firmware/ethereum.c

@@ -294,7 +294,15 @@ static void layoutEthereumConfirmTx(const uint8_t *to, uint32_t to_len, const ui
 
 	if (to_len) {
 		char to_str[41];
-		ethereum_address_checksum(to, to_str, false, 0);
+
+		bool rskip60 = false;
+		// constants from trezor-common/defs/ethereum/networks.json
+		switch (chain_id) {
+			case 30: rskip60 = true; break;
+			case 31: rskip60 = true; break;
+		}
+
+		ethereum_address_checksum(to, to_str, rskip60, chain_id);
 		memcpy(_to1 + 5, to_str, 10);
 		memcpy(_to2, to_str + 10, 15);
 		memcpy(_to3, to_str + 25, 15);

firmware/fsm_msg_ethereum.h

@@ -35,8 +35,17 @@ void fsm_msgEthereumGetAddress(EthereumGetAddress *msg)
 		char desc[16];
 		strlcpy(desc, "Address:", sizeof(desc));
 
+		uint32_t slip44 = msg->address_n[1] & 0x7fffffff;
+		bool rskip60 = false;
+		uint32_t chain_id = 0;
+		// constants from trezor-common/defs/ethereum/networks.json
+		switch (slip44) {
+			case 137: rskip60 = true; chain_id = 30; break;
+			case 37310: rskip60 = true; chain_id = 31; break;
+		}
+
 		char address[43] = { '0', 'x' };
-		ethereum_address_checksum(resp->address.bytes, address + 2, false, 0);
+		ethereum_address_checksum(resp->address.bytes, address + 2, rskip60, chain_id);
 
 		if (!fsm_layoutAddress(address, desc, false, 0, msg->address_n, msg->address_n_count)) {
 			return;