more addr message error checking

[VerusCoin.git] / base58.h

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