From 4153e662b60a0d83c1be15150f18483a37e9092c Mon Sep 17 00:00:00 2001
From: Ilan <ilan@rsk.co>
Date: Tue, 19 Jun 2018 14:52:39 -0300
Subject: [PATCH] Implement RSKIP-60 checksum address encoding

---
 address.c          | 18 ++++++++++++++++--
 address.h          |  2 +-
 tests/test_check.c | 44 +++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 60 insertions(+), 4 deletions(-)

diff --git a/address.c b/address.c
index 4d63f8ee3a..3fa9f8927a 100644
--- a/address.c
+++ b/address.c
@@ -22,6 +22,9 @@
  */
 
 #include "address.h"
+#include <stdio.h>
+#include <string.h>
+#include "bignum.h"
 
 size_t address_prefix_bytes_len(uint32_t address_type)
 {
@@ -56,7 +59,7 @@ bool address_check_prefix(const uint8_t *addr, uint32_t address_type)
 #if USE_ETHEREUM
 #include "sha3.h"
 
-void ethereum_address_checksum(const uint8_t *addr, char *address)
+void ethereum_address_checksum(const uint8_t *addr, char *address, bool rskip60, uint8_t chain_id)
 {
 	const char *hex = "0123456789abcdef";
 	for (int i = 0; i < 20; i++) {
@@ -64,8 +67,19 @@ void ethereum_address_checksum(const uint8_t *addr, char *address)
 		address[i * 2 + 1] = hex[addr[i] & 0xF];
 	}
 	address[40] = 0;
+
+	SHA3_CTX ctx;
 	uint8_t hash[32];
-	keccak_256((const uint8_t *)address, 40, hash);
+	keccak_256_Init(&ctx);
+	if(rskip60)
+	{
+		char prefix[16];
+		int prefix_size = bn_format_uint64(chain_id, NULL, "0x", 0, 0, false, prefix, sizeof(prefix));
+		keccak_Update(&ctx, (const uint8_t *)prefix, prefix_size);
+	}
+	keccak_Update(&ctx, (const uint8_t *)address, 40);
+	keccak_Final(&ctx, hash);
+
 	for (int i = 0; i < 20; i++) {
 		if (hash[i] & 0x80 && address[i * 2    ] >= 'a' && address[i * 2    ] <= 'f') {
 			address[i * 2] -= 0x20;
diff --git a/address.h b/address.h
index 307cf8dc8a..c70a1f28a3 100644
--- a/address.h
+++ b/address.h
@@ -33,7 +33,7 @@ size_t address_prefix_bytes_len(uint32_t address_type);
 void address_write_prefix_bytes(uint32_t address_type, uint8_t *out);
 bool address_check_prefix(const uint8_t *addr, uint32_t address_type);
 #if USE_ETHEREUM
-void ethereum_address_checksum(const uint8_t *addr, char *address);
+void ethereum_address_checksum(const uint8_t *addr, char *address, bool rskip60, uint8_t chain_id);
 #endif
 
 #endif
diff --git a/tests/test_check.c b/tests/test_check.c
index 388aec3379..7af2136f17 100644
--- a/tests/test_check.c
+++ b/tests/test_check.c
@@ -3802,7 +3802,45 @@ START_TEST(test_ethereum_address)
 	const char **vec = vectors;
 	while (*vec) {
 		memcpy(addr, fromhex(*vec), 20);
-		ethereum_address_checksum(addr, address);
+		ethereum_address_checksum(addr, address, false, 1);
+		ck_assert_str_eq(address, *vec);
+		vec++;
+	}
+}
+END_TEST
+
+// test vectors from https://github.com/rsksmart/RSKIPs/blob/master/IPs/RSKIP60.md
+START_TEST(test_rsk_address)
+{
+	uint8_t addr[20];
+	char address[41];
+
+	static const char *rskip60_chain30[] = {
+		"5aaEB6053f3e94c9b9a09f33669435E7ef1bEAeD",
+		"Fb6916095cA1Df60bb79ce92cE3EA74c37c5d359",
+		"DBF03B407c01E7CD3cBea99509D93F8Dddc8C6FB",
+		"D1220A0Cf47c7B9BE7a2e6ba89F429762E7B9adB",
+		0
+	};
+	const char **vec = rskip60_chain30;
+	while (*vec) {
+		memcpy(addr, fromhex(*vec), 20);
+		ethereum_address_checksum(addr, address, true, 30);
+		ck_assert_str_eq(address, *vec);
+		vec++;
+	}
+
+	static const char *rskip60_chain31[] = {
+		"5aAeb6053F3e94c9b9A09F33669435E7EF1BEaEd",
+		"Fb6916095CA1dF60bb79CE92ce3Ea74C37c5D359",
+		"dbF03B407C01E7cd3cbEa99509D93f8dDDc8C6fB",
+		"d1220a0CF47c7B9Be7A2E6Ba89f429762E7b9adB",
+		0
+	};
+	vec = rskip60_chain31;
+	while (*vec) {
+		memcpy(addr, fromhex(*vec), 20);
+		ethereum_address_checksum(addr, address, true, 31);
 		ck_assert_str_eq(address, *vec);
 		vec++;
 	}
@@ -4744,6 +4782,10 @@ Suite *test_suite(void)
 	tcase_add_test(tc, test_ethereum_address);
 	suite_add_tcase(s, tc);
 
+	tc = tcase_create("rsk_address");
+	tcase_add_test(tc, test_rsk_address);
+	suite_add_tcase(s, tc);
+
 	tc = tcase_create("wif");
 	tcase_add_test(tc, test_wif);
 	suite_add_tcase(s, tc);