Replace DecodeBase58/EncodeBase58 with direct implementation.

This removes the bignum/OpenSSL dependency.

The base58 transformation code is also moved to a separate .cpp file.

1 files changed, 91 insertions, 0 deletions

diff --git a/src/base58.cpp b/src/base58.cpp
new file mode 100644
index 0000000000..0b08ee3d06
--- /dev/null
+++ b/src/base58.cpp
@@ -0,0 +1,91 @@
+// Copyright (c) 2014 The Bitcoin developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <assert.h>
+#include <stdint.h>
+#include <string.h>
+#include <vector>
+#include <string>
+
+/* All alphanumeric characters except for "0", "I", "O", and "l" */
+static const char* pszBase58 = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
+
+bool DecodeBase58(const char *psz, std::vector<unsigned char>& vch) {
+    // Skip leading spaces.
+    while (*psz && isspace(*psz))
+        psz++;
+    // Skip and count leading '1's.
+    int zeroes = 0;
+    while (*psz == '1') {
+        zeroes++;
+        psz++;
+    }
+    // Allocate enough space in big-endian base256 representation.
+    std::vector<unsigned char> b256(strlen(psz) * 733 / 1000 + 1); // log(58) / log(256), rounded up.
+    // Process the characters.
+    while (*psz && !isspace(*psz)) {
+        // Decode base58 character
+        const char *ch = strchr(pszBase58, *psz);
+        if (ch == NULL)
+            return false;
+        // Apply "b256 = b256 * 58 + ch".
+        int carry = ch - pszBase58;
+        for (std::vector<unsigned char>::reverse_iterator it = b256.rbegin(); it != b256.rend(); it++) {
+            carry += 58 * (*it);
+            *it = carry % 256;
+            carry /= 256;
+        }
+        assert(carry == 0);
+        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();
+    while (it != b256.end() && *it == 0)
+        it++;
+    // 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(const unsigned char* pbegin, const unsigned char* pend) {
+    // Skip & count leading zeroes.
+    int zeroes = 0;
+    while (pbegin != pend && *pbegin == 0) {
+        pbegin++;
+        zeroes++;
+    }
+    // Allocate enough space in big-endian base58 representation.
+    std::vector<unsigned char> b58((pend - pbegin) * 138 / 100 + 1); // log(256) / log(58), rounded up.
+    // Process the bytes.
+    while (pbegin != pend) {
+        int carry = *pbegin;
+        // Apply "b58 = b58 * 256 + ch".
+        for (std::vector<unsigned char>::reverse_iterator it = b58.rbegin(); it != b58.rend(); it++) {
+            carry += 256 * (*it);
+            *it = carry % 58;
+            carry /= 58;
+        }
+        assert(carry == 0);
+        pbegin++;
+    }
+    // Skip leading zeroes in base58 result.
+    std::vector<unsigned char>::iterator it = b58.begin();
+    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;
+}