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This removes the bignum/OpenSSL dependency. The base58 transformation code is also moved to a separate .cpp file.pull/145/head
Pieter Wuille
10 years ago
3 changed files with 101 additions and 93 deletions
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// Copyright (c) 2014 The Bitcoin developers
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// Distributed under the MIT/X11 software license, see the accompanying
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// file COPYING or http://www.opensource.org/licenses/mit-license.php.
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#include <assert.h> |
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#include <stdint.h> |
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#include <string.h> |
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#include <vector> |
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#include <string> |
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/* All alphanumeric characters except for "0", "I", "O", and "l" */ |
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static const char* pszBase58 = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"; |
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bool DecodeBase58(const char *psz, std::vector<unsigned char>& vch) { |
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// Skip leading spaces.
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while (*psz && isspace(*psz)) |
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psz++; |
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// Skip and count leading '1's.
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int zeroes = 0; |
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while (*psz == '1') { |
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zeroes++; |
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psz++; |
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} |
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// Allocate enough space in big-endian base256 representation.
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std::vector<unsigned char> b256(strlen(psz) * 733 / 1000 + 1); // log(58) / log(256), rounded up.
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// Process the characters.
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while (*psz && !isspace(*psz)) { |
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// Decode base58 character
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const char *ch = strchr(pszBase58, *psz); |
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if (ch == NULL) |
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return false; |
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// Apply "b256 = b256 * 58 + ch".
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int carry = ch - pszBase58; |
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for (std::vector<unsigned char>::reverse_iterator it = b256.rbegin(); it != b256.rend(); it++) { |
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carry += 58 * (*it); |
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*it = carry % 256; |
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carry /= 256; |
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} |
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assert(carry == 0); |
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psz++; |
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} |
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// Skip trailing spaces.
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while (isspace(*psz)) |
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psz++; |
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if (*psz != 0) |
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return false; |
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// Skip leading zeroes in b256.
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std::vector<unsigned char>::iterator it = b256.begin(); |
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while (it != b256.end() && *it == 0) |
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it++; |
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// Copy result into output vector.
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vch.reserve(zeroes + (b256.end() - it)); |
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vch.assign(zeroes, 0x00); |
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while (it != b256.end()) |
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vch.push_back(*(it++)); |
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return true; |
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} |
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std::string EncodeBase58(const unsigned char* pbegin, const unsigned char* pend) { |
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// Skip & count leading zeroes.
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int zeroes = 0; |
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while (pbegin != pend && *pbegin == 0) { |
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pbegin++; |
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zeroes++; |
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} |
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// Allocate enough space in big-endian base58 representation.
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std::vector<unsigned char> b58((pend - pbegin) * 138 / 100 + 1); // log(256) / log(58), rounded up.
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// Process the bytes.
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while (pbegin != pend) { |
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int carry = *pbegin; |
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// Apply "b58 = b58 * 256 + ch".
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for (std::vector<unsigned char>::reverse_iterator it = b58.rbegin(); it != b58.rend(); it++) { |
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carry += 256 * (*it); |
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*it = carry % 58; |
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carry /= 58; |
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} |
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assert(carry == 0); |
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pbegin++; |
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} |
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// Skip leading zeroes in base58 result.
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std::vector<unsigned char>::iterator it = b58.begin(); |
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while (it != b58.end() && *it == 0) |
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it++; |
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// Translate the result into a string.
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std::string str; |
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str.reserve(zeroes + (b58.end() - it)); |
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str.assign(zeroes, '1'); |
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while (it != b58.end()) |
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str += pszBase58[*(it++)]; |
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return str; |
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} |
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