util: Port of Bitcoin upstream base58.h/cpp at a85442f62bf157b07849accd495c55c73535dc73

src/Makefile.am

@@ -204,6 +204,7 @@ GRIDCOIN_CORE_CPP = addrdb.cpp \
     alert.cpp \
     arith_uint256.cpp \
     banman.cpp \
+    base58.cpp \
     chainparams.cpp \
     chainparamsbase.cpp \
     checkpoints.cpp \

src/base58.cpp

@@ -0,0 +1,179 @@
+// Copyright (c) 2014-2020 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <base58.h>
+
+#include <hash.h>
+#include <uint256.h>
+#include <util/strencodings.h>
+#include <util/string.h>
+
+#include <assert.h>
+#include <string.h>
+
+#include <limits>
+
+/** All alphanumeric characters except for "0", "I", "O", and "l" */
+static const char* pszBase58 = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
+static const int8_t mapBase58[256] = {
+    -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,
+    -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,-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,-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,
+};
+
+[[nodiscard]] static bool DecodeBase58(const char* psz, std::vector<unsigned char>& vch, int max_ret_len)
+{
+    // Skip leading spaces.
+    while (*psz && IsSpace(*psz))
+        psz++;
+    // Skip and count leading '1's.
+    int zeroes = 0;
+    int length = 0;
+    while (*psz == '1') {
+        zeroes++;
+        if (zeroes > max_ret_len) return false;
+        psz++;
+    }
+    // Allocate enough space in big-endian base256 representation.
+    int size = strlen(psz) * 733 /1000 + 1; // log(58) / log(256), rounded up.
+    std::vector<unsigned char> b256(size);
+    // Process the characters.
+    static_assert(std::size(mapBase58) == 256, "mapBase58.size() should be 256"); // guarantee not out of range
+    while (*psz && !IsSpace(*psz)) {
+        // Decode base58 character
+        int carry = mapBase58[(uint8_t)*psz];
+        if (carry == -1)  // Invalid b58 character
+            return false;
+        int i = 0;
+        for (std::vector<unsigned char>::reverse_iterator it = b256.rbegin(); (carry != 0 || i < length) && (it != b256.rend()); ++it, ++i) {
+            carry += 58 * (*it);
+            *it = carry % 256;
+            carry /= 256;
+        }
+        assert(carry == 0);
+        length = i;
+        if (length + zeroes > max_ret_len) return false;
+        psz++;
+    }
+    // Skip trailing spaces.
+    while (IsSpace(*psz))
+        psz++;
+    if (*psz != 0)
+        return false;
+    // Skip leading zeroes in b256.
+    std::vector<unsigned char>::iterator it = b256.begin() + (size - length);
+    // Copy result into output vector.
+    vch.reserve(zeroes + (b256.end() - it));
+    vch.assign(zeroes, 0x00);
+    while (it != b256.end())
+        vch.push_back(*(it++));
+    return true;
+}
+
+std::string EncodeBase58(Span<const unsigned char> input)
+{
+    // Skip & count leading zeroes.
+    int zeroes = 0;
+    int length = 0;
+    while (input.size() > 0 && input[0] == 0) {
+        input = input.subspan(1);
+        zeroes++;
+    }
+    // Allocate enough space in big-endian base58 representation.
+    int size = input.size() * 138 / 100 + 1; // log(256) / log(58), rounded up.
+    std::vector<unsigned char> b58(size);
+    // Process the bytes.
+    while (input.size() > 0) {
+        int carry = input[0];
+        int i = 0;
+        // Apply "b58 = b58 * 256 + ch".
+        for (std::vector<unsigned char>::reverse_iterator it = b58.rbegin(); (carry != 0 || i < length) && (it != b58.rend()); it++, i++) {
+            carry += 256 * (*it);
+            *it = carry % 58;
+            carry /= 58;
+        }
+
+        assert(carry == 0);
+        length = i;
+        input = input.subspan(1);
+    }
+    // Skip leading zeroes in base58 result.
+    std::vector<unsigned char>::iterator it = b58.begin() + (size - length);
+    while (it != b58.end() && *it == 0)
+        it++;
+    // Translate the result into a string.
+    std::string str;
+    str.reserve(zeroes + (b58.end() - it));
+    str.assign(zeroes, '1');
+    while (it != b58.end())
+        str += pszBase58[*(it++)];
+    return str;
+}
+
+std::string EncodeBase58(const unsigned char* pbegin, const unsigned char* pend)
+{
+    return EncodeBase58(Span<const unsigned char>(pbegin, pend));
+}
+
+bool DecodeBase58(const std::string& str, std::vector<unsigned char>& vchRet, int max_ret_len)
+{
+    if (!ValidAsCString(str)) {
+        return false;
+    }
+    return DecodeBase58(str.c_str(), vchRet, max_ret_len);
+}
+
+std::string EncodeBase58Check(Span<const unsigned char> input)
+{
+    // add 4-byte hash check to the end
+    std::vector<unsigned char> vch(input.begin(), input.end());
+    // Can't use spans here until we teach hash.h about them.
+    uint256 hash = Hash(vch.begin(), vch.end());
+    vch.insert(vch.end(), (unsigned char*)&hash, (unsigned char*)&hash + 4);
+    return EncodeBase58(vch);
+}
+
+std::string EncodeBase58Check(const std::vector<unsigned char>& vchIn)
+{
+    return EncodeBase58Check(Span<const unsigned char>(vchIn));
+}
+
+[[nodiscard]] static bool DecodeBase58Check(const char* psz, std::vector<unsigned char>& vchRet, int max_ret_len)
+{
+    if (!DecodeBase58(psz, vchRet, max_ret_len > std::numeric_limits<int>::max() - 4 ? std::numeric_limits<int>::max() : max_ret_len + 4) ||
+        (vchRet.size() < 4)) {
+        vchRet.clear();
+        return false;
+    }
+    // re-calculate the checksum, ensure it matches the included 4-byte checksum
+    // Can't use spans here until we teach hash.h about them.
+    uint256 hash = Hash(vchRet.begin(), vchRet.end() - 4);
+    if (memcmp(&hash, &vchRet[vchRet.size() - 4], 4) != 0) {
+        vchRet.clear();
+        return false;
+    }
+    vchRet.resize(vchRet.size() - 4);
+    return true;
+}
+
+bool DecodeBase58Check(const std::string& str, std::vector<unsigned char>& vchRet, int max_ret)
+{
+    if (!ValidAsCString(str)) {
+        return false;
+    }
+    return DecodeBase58Check(str.c_str(), vchRet, max_ret);
+}