From 54cc18c4935a1566fd0407e74deaf4dc542a33df Mon Sep 17 00:00:00 2001
From: Fabian Schuh <mail@xeroc.org>
Date: Tue, 27 Sep 2016 22:48:36 +0200
Subject: [PATCH] Steem integration

---
 Makefile  |  1 +
 base58.c  | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 base58.h  |  6 ++++++
 options.h |  5 +++++
 tests.c   | 37 +++++++++++++++++++++++++++++++++++-
 5 files changed, 104 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 16e667a59..c62447b17 100644
--- a/Makefile
+++ b/Makefile
@@ -31,6 +31,7 @@ CFLAGS += -DED25519_NO_INLINE_ASM
 CFLAGS += -DED25519_FORCE_32BIT=1
 CFLAGS += -Ied25519-donna -Icurve25519-donna -I.
 CFLAGS += -DUSE_ETHEREUM=1
+CFLAGS += -DUSE_GRAPHENE=1
 
 # disable certain optimizations and features when small footprint is required
 ifdef SMALL
diff --git a/base58.c b/base58.c
index 5355fcb1e..2c44d3985 100644
--- a/base58.c
+++ b/base58.c
@@ -27,6 +27,7 @@
 #include "base58.h"
 #include "sha2.h"
 #include "macros.h"
+#include "ripemd160.h"
 
 static const int8_t b58digits_map[] = {
 	-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
@@ -217,3 +218,58 @@ int base58_decode_check(const char *str, uint8_t *data, int datalen)
 	memcpy(data, nd, res - 4);
 	return res - 4;
 }
+
+#if USE_GRAPHENE
+int b58gphcheck(const void *bin, size_t binsz, const char *base58str)
+{
+	unsigned char buf[32];
+	const uint8_t *binc = bin;
+	unsigned i;
+	if (binsz < 4)
+		return -4;
+	ripemd160(bin, binsz - 4, buf);  // No double SHA256, but a single RIPEMD160
+	if (memcmp(&binc[binsz - 4], buf, 4))
+		return -1;
+
+	// Check number of zeros is correct AFTER verifying checksum (to avoid possibility of accessing base58str beyond the end)
+	for (i = 0; binc[i] == '\0' && base58str[i] == '1'; ++i)
+	{}  // Just finding the end of zeros, nothing to do in loop
+	if (binc[i] == '\0' || base58str[i] == '1')
+		return -3;
+
+	return binc[0];
+}
+
+int base58gph_encode_check(const uint8_t *data, int datalen, char *str, int strsize)
+{
+	if (datalen > 128) {
+		return 0;
+	}
+	uint8_t buf[datalen + 32];
+	uint8_t *hash = buf + datalen;
+	memcpy(buf, data, datalen);
+	ripemd160(data, datalen, hash);  // No double SHA256, but a single RIPEMD160
+	size_t res = strsize;
+	bool success = b58enc(str, &res, buf, datalen + 4);
+	MEMSET_BZERO(buf, sizeof(buf));
+	return success ? res : 0;
+}
+
+int base58gph_decode_check(const char *str, uint8_t *data, int datalen)
+{
+	if (datalen > 128) {
+		return 0;
+	}
+	uint8_t d[datalen + 4];
+	size_t res = datalen + 4;
+	if (b58tobin(d, &res, str) != true) {
+		return 0;
+	}
+	uint8_t *nd = d + datalen + 4 - res;
+	if (b58gphcheck(nd, res, str) < 0) {
+		return 0;
+	}
+	memcpy(data, nd, res - 4);
+	return res - 4;
+}
+#endif
diff --git a/base58.h b/base58.h
index a53e4385b..094849bae 100644
--- a/base58.h
+++ b/base58.h
@@ -35,4 +35,10 @@ bool b58tobin(void *bin, size_t *binszp, const char *b58);
 int b58check(const void *bin, size_t binsz, const char *base58str);
 bool b58enc(char *b58, size_t *b58sz, const void *data, size_t binsz);
 
+#if USE_GRAPHENE
+int base58gph_encode_check(const uint8_t *data, int datalen, char *str, int strsize);
+int base58gph_decode_check(const char *str, uint8_t *data, int datalen);
+int b58gphcheck(const void *bin, size_t binsz, const char *base58str);
+#endif
+
 #endif
diff --git a/options.h b/options.h
index fabca9f9b..6b7de989b 100644
--- a/options.h
+++ b/options.h
@@ -61,6 +61,11 @@
 #define USE_ETHEREUM 0
 #endif
 
+// support Graphene operations (STEEM, BitShares)
+#ifndef USE_GRAPHENE
+#define USE_GRAPHENE 0
+#endif
+
 // support Keccak hashing
 #ifndef USE_KECCAK
 #define USE_KECCAK USE_ETHEREUM
diff --git a/tests.c b/tests.c
index 40a3d6dd4..3a492db10 100644
--- a/tests.c
+++ b/tests.c
@@ -442,6 +442,38 @@ START_TEST(test_base58)
 }
 END_TEST
 
+// Graphene Base85CheckEncoding
+START_TEST(test_base58gph)
+{
+	static const char *base58_vector[] = {
+		"02e649f63f8e8121345fd7f47d0d185a3ccaa843115cd2e9392dcd9b82263bc680", "6dumtt9swxCqwdPZBGXh9YmHoEjFFnNfwHaTqRbQTghGAY2gRz",
+		"021c7359cd885c0e319924d97e3980206ad64387aff54908241125b3a88b55ca16", "5725vivYpuFWbeyTifZ5KevnHyqXCi5hwHbNU9cYz1FHbFXCxX",
+		"02f561e0b57a552df3fa1df2d87a906b7a9fc33a83d5d15fa68a644ecb0806b49a", "6kZKHSuxqAwdCYsMvwTcipoTsNE2jmEUNBQufGYywpniBKXWZK",
+		"03e7595c3e6b58f907bee951dc29796f3757307e700ecf3d09307a0cc4a564eba3", "8b82mpnH8YX1E9RHnU2a2YgLTZ8ooevEGP9N15c1yFqhoBvJur",
+		0, 0,
+	};
+	const char **raw = base58_vector;
+	const char **str = base58_vector + 1;
+	uint8_t rawn[34];
+	char strn[53];
+	int r;
+	while (*raw && *str) {
+		int len = strlen(*raw) / 2;
+
+		memcpy(rawn, fromhex(*raw), len);
+		r = base58gph_encode_check(rawn, len, strn, sizeof(strn));
+		ck_assert_int_eq((size_t)r, strlen(*str) + 1);
+		ck_assert_str_eq(strn, *str);
+
+		r = base58gph_decode_check(strn, rawn, len);
+		ck_assert_int_eq(r, len);
+		ck_assert_mem_eq(rawn,  fromhex(*raw), len);
+
+		raw += 2; str += 2;
+	}
+}
+END_TEST
+
 START_TEST(test_bignum_divmod)
 {
 	uint32_t r;
@@ -2603,7 +2635,6 @@ START_TEST(test_ethereum_pubkeyhash)
 }
 END_TEST
 
-
 // define test suite and cases
 Suite *test_suite(void)
 {
@@ -2634,6 +2665,10 @@ Suite *test_suite(void)
 	tcase_add_test(tc, test_base58);
 	suite_add_tcase(s, tc);
 
+	tc = tcase_create("base58gph");
+	tcase_add_test(tc, test_base58gph);
+	suite_add_tcase(s, tc);
+
 	tc = tcase_create("bignum_divmod");
 	tcase_add_test(tc, test_bignum_divmod);
 	suite_add_tcase(s, tc);