First commit

git-svn-id: https://bitcoin.svn.sourceforge.net/svnroot/bitcoin/trunk@1 1a98c847-1fd6-4fd8-948a-caf3550aa51b

base58.h

@@ -0,0 +1,201 @@
+// Copyright (c) 2009 Satoshi Nakamoto
+// Distributed under the MIT/X11 software license, see the accompanying
+// file license.txt or http://www.opensource.org/licenses/mit-license.php.
+
+
+//
+// Why base-58 instead of standard base-64 encoding?
+// - Don't want 0OIl characters that look the same in some fonts and
+//      could be used to create visually identical looking account numbers.
+// - A string with non-alphanumeric characters is not as easily accepted as an account number.
+// - E-mail usually won't line-break if there's no punctuation to break at.
+// - Doubleclicking selects the whole number as one word if it's all alphanumeric.
+//
+
+
+static const char* pszBase58 = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
+
+
+inline string EncodeBase58(const unsigned char* pbegin, const unsigned char* pend)
+{
+    CAutoBN_CTX pctx;
+    CBigNum bn58 = 58;
+    CBigNum bn0 = 0;
+
+    // Convert big endian data to little endian
+    // Extra zero at the end make sure bignum will interpret as a positive number
+    vector<unsigned char> vchTmp(pend-pbegin+1, 0);
+    reverse_copy(pbegin, pend, vchTmp.begin());
+
+    // Convert little endian data to bignum
+    CBigNum bn;
+    bn.setvch(vchTmp);
+
+    // Convert bignum to string
+    string str;
+    str.reserve((pend - pbegin) * 138 / 100 + 1);
+    CBigNum dv;
+    CBigNum rem;
+    while (bn > bn0)
+    {
+        if (!BN_div(&dv, &rem, &bn, &bn58, pctx))
+            throw bignum_error("EncodeBase58 : BN_div failed");
+        bn = dv;
+        unsigned int c = rem.getulong();
+        str += pszBase58[c];
+    }
+
+    // Leading zeroes encoded as base58 zeros
+    for (const unsigned char* p = pbegin; p < pend && *p == 0; p++)
+        str += pszBase58[0];
+
+    // Convert little endian string to big endian
+    reverse(str.begin(), str.end());
+    return str;
+}
+
+inline string EncodeBase58(const vector<unsigned char>& vch)
+{
+    return EncodeBase58(&vch[0], &vch[0] + vch.size());
+}
+
+inline bool DecodeBase58(const char* psz, vector<unsigned char>& vchRet)
+{
+    CAutoBN_CTX pctx;
+    vchRet.clear();
+    CBigNum bn58 = 58;
+    CBigNum bn = 0;
+    CBigNum bnChar;
+    while (isspace(*psz))
+        psz++;
+
+    // Convert big endian string to bignum
+    for (const char* p = psz; *p; p++)
+    {
+        const char* p1 = strchr(pszBase58, *p);
+        if (p1 == NULL)
+        {
+            while (isspace(*p))
+                p++;
+            if (*p != '\0')
+                return false;
+            break;
+        }
+        bnChar.setulong(p1 - pszBase58);
+        if (!BN_mul(&bn, &bn, &bn58, pctx))
+            throw bignum_error("DecodeBase58 : BN_mul failed");
+        bn += bnChar;
+    }
+
+    // Get bignum as little endian data
+    vector<unsigned char> vchTmp = bn.getvch();
+
+    // Trim off sign byte if present
+    if (vchTmp.size() >= 2 && vchTmp.end()[-1] == 0 && vchTmp.end()[-2] >= 0x80)
+        vchTmp.erase(vchTmp.end()-1);
+
+    // Restore leading zeros
+    int nLeadingZeros = 0;
+    for (const char* p = psz; *p == pszBase58[0]; p++)
+        nLeadingZeros++;
+    vchRet.assign(nLeadingZeros + vchTmp.size(), 0);
+
+    // Convert little endian data to big endian
+    reverse_copy(vchTmp.begin(), vchTmp.end(), vchRet.end() - vchTmp.size());
+    return true;
+}
+
+inline bool DecodeBase58(const string& str, vector<unsigned char>& vchRet)
+{
+    return DecodeBase58(str.c_str(), vchRet);
+}
+
+
+
+
+
+inline string EncodeBase58Check(const vector<unsigned char>& vchIn)
+{
+    // add 4-byte hash check to the end
+    vector<unsigned char> vch(vchIn);
+    uint256 hash = Hash(vch.begin(), vch.end());
+    vch.insert(vch.end(), (unsigned char*)&hash, (unsigned char*)&hash + 4);
+    return EncodeBase58(vch);
+}
+
+inline bool DecodeBase58Check(const char* psz, vector<unsigned char>& vchRet)
+{
+    if (!DecodeBase58(psz, vchRet))
+        return false;
+    if (vchRet.size() < 4)
+    {
+        vchRet.clear();
+        return false;
+    }
+    uint256 hash = Hash(vchRet.begin(), vchRet.end()-4);
+    if (memcmp(&hash, &vchRet.end()[-4], 4) != 0)
+    {
+        vchRet.clear();
+        return false;
+    }
+    vchRet.resize(vchRet.size()-4);
+    return true;
+}
+
+inline bool DecodeBase58Check(const string& str, vector<unsigned char>& vchRet)
+{
+    return DecodeBase58Check(str.c_str(), vchRet);
+}
+
+
+
+
+
+
+static const unsigned char ADDRESSVERSION = 0;
+
+inline string Hash160ToAddress(uint160 hash160)
+{
+    // add 1-byte version number to the front
+    vector<unsigned char> vch(1, ADDRESSVERSION);
+    vch.insert(vch.end(), UBEGIN(hash160), UEND(hash160));
+    return EncodeBase58Check(vch);
+}
+
+inline bool AddressToHash160(const char* psz, uint160& hash160Ret)
+{
+    vector<unsigned char> vch;
+    if (!DecodeBase58Check(psz, vch))
+        return false;
+    if (vch.empty())
+        return false;
+    unsigned char nVersion = vch[0];
+    if (vch.size() != sizeof(hash160Ret) + 1)
+        return false;
+    memcpy(&hash160Ret, &vch[1], sizeof(hash160Ret));
+    return (nVersion <= ADDRESSVERSION);
+}
+
+inline bool AddressToHash160(const string& str, uint160& hash160Ret)
+{
+    return AddressToHash160(str.c_str(), hash160Ret);
+}
+
+inline bool IsValidBitcoinAddress(const char* psz)
+{
+    uint160 hash160;
+    return AddressToHash160(psz, hash160);
+}
+
+inline bool IsValidBitcoinAddress(const string& str)
+{
+    return IsValidBitcoinAddress(str.c_str());
+}
+
+
+
+
+inline string PubKeyToAddress(const vector<unsigned char>& vchPubKey)
+{
+    return Hash160ToAddress(Hash160(vchPubKey));
+}