Master (#173)

* Create base58.c

* Create base58.h

* Update base58.c

* Update base58.h

crypto/base58.c

@@ -0,0 +1,150 @@
+/*
+ * Copyright 2012-2014 Luke Dashjr
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the standard MIT license.  See COPYING for more details.
+ */
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/types.h>
+
+#include "base58.h"
+
+static const int8_t b58digits_map[] = {
+	-1,-1,-1,-1,-1,-1,-1,-1, -1,-1,-1,-1,-1,-1,-1,-1,
+	-1,-1,-1,-1,-1,-1,-1,-1, -1,-1,-1,-1,-1,-1,-1,-1,
+	-1,-1,-1,-1,-1,-1,-1,-1, -1,-1,-1,-1,-1,-1,-1,-1,
+	-1, 0, 1, 2, 3, 4, 5, 6,  7, 8,-1,-1,-1,-1,-1,-1,
+	-1, 9,10,11,12,13,14,15, 16,-1,17,18,19,20,21,-1,
+	22,23,24,25,26,27,28,29, 30,31,32,-1,-1,-1,-1,-1,
+	-1,33,34,35,36,37,38,39, 40,41,42,43,-1,44,45,46,
+	47,48,49,50,51,52,53,54, 55,56,57,-1,-1,-1,-1,-1,
+};
+
+bool base58_decode(const char *b58, size_t b58sz, void *bin, size_t *binszp)
+{
+	size_t binsz = *binszp;
+	const unsigned char *b58u = (void*)b58;
+	unsigned char *binu = bin;
+	size_t outisz = (binsz + 3) / 4;
+	uint32_t outi[outisz];
+	uint64_t t;
+	uint32_t c;
+	size_t i, j;
+	uint8_t bytesleft = binsz % 4;
+	uint32_t zeromask = bytesleft ? (0xffffffff << (bytesleft * 8)) : 0;
+	unsigned zerocount = 0;
+	
+	if (!b58sz)
+		b58sz = strlen(b58);
+	
+	memset(outi, 0, outisz * sizeof(*outi));
+	
+	// Leading zeros, just count
+	for (i = 0; i < b58sz && b58u[i] == '1'; ++i)
+		++zerocount;
+	
+	for ( ; i < b58sz; ++i)
+	{
+		if (b58u[i] & 0x80)
+			// High-bit set on invalid digit
+			return false;
+		if (b58digits_map[b58u[i]] == -1)
+			// Invalid base58 digit
+			return false;
+		c = (unsigned)b58digits_map[b58u[i]];
+		for (j = outisz; j--; )
+		{
+			t = ((uint64_t)outi[j]) * 58 + c;
+			c = (t & 0x3f00000000) >> 32;
+			outi[j] = t & 0xffffffff;
+		}
+		if (c)
+			// Output number too big (carry to the next int32)
+			return false;
+		if (outi[0] & zeromask)
+			// Output number too big (last int32 filled too far)
+			return false;
+	}
+	
+	j = 0;
+	switch (bytesleft) {
+		case 3:
+			*(binu++) = (outi[0] &   0xff0000) >> 16;
+		case 2:
+			*(binu++) = (outi[0] &     0xff00) >>  8;
+		case 1:
+			*(binu++) = (outi[0] &       0xff);
+			++j;
+		default:
+			break;
+	}
+	
+	for (; j < outisz; ++j)
+	{
+		*(binu++) = (outi[j] >> 0x18) & 0xff;
+		*(binu++) = (outi[j] >> 0x10) & 0xff;
+		*(binu++) = (outi[j] >>    8) & 0xff;
+		*(binu++) = (outi[j] >>    0) & 0xff;
+	}
+	
+	// Count canonical base58 byte count
+	binu = bin;
+	for (i = 0; i < binsz; ++i)
+	{
+		if (binu[i])
+			break;
+		--*binszp;
+	}
+	*binszp += zerocount;
+	
+	return true;
+}
+
+static const char b58digits_ordered[] = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
+
+bool base58_encode(const void *data, size_t binsz, char *b58, size_t *b58sz)
+{
+	const uint8_t *bin = data;
+	int carry;
+	ssize_t i, j, high, zcount = 0;
+	size_t size;
+	
+	while (zcount < binsz && !bin[zcount])
+		++zcount;
+	
+	size = (binsz - zcount) * 138 / 100 + 1;
+	uint8_t buf[size];
+	memset(buf, 0, size);
+	
+	for (i = zcount, high = size - 1; i < binsz; ++i, high = j)
+	{
+		for (carry = bin[i], j = size - 1; (j > high) || carry; --j)
+		{
+			carry += 256 * buf[j];
+			buf[j] = carry % 58;
+			carry /= 58;
+		}
+	}
+	
+	for (j = 0; j < size && !buf[j]; ++j);
+	
+	if (*b58sz <= zcount + size - j)
+	{
+		*b58sz = zcount + size - j + 1;
+		return false;
+	}
+	
+	if (zcount)
+		memset(b58, '1', zcount);
+	for (i = zcount; j < size; ++i, ++j)
+		b58[i] = b58digits_ordered[buf[j]];
+	b58[i] = '\0';
+	*b58sz = i + 1;
+	
+	return true;
+}
+

include/openssl/base58.h

@@ -0,0 +1,14 @@
+#ifndef LIBBASE58_H
+#define LIBBASE58_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+bool base58_decode(const char *b58, size_t b58sz, void *bin, size_t *binszp);
+bool base58_encode(const void *data, size_t binsz, char *b58, size_t *b58sz);
+
+#endif
+
+
+