1 // Copyright (c) 2009-2010 Satoshi Nakamoto
2 // Copyright (c) 2009-2012 The Bitcoin Developers
3 // Distributed under the MIT/X11 software license, see the accompanying
4 // file license.txt or http://www.opensource.org/licenses/mit-license.php.
8 // Why base-58 instead of standard base-64 encoding?
9 // - Don't want 0OIl characters that look the same in some fonts and
10 // could be used to create visually identical looking account numbers.
11 // - A string with non-alphanumeric characters is not as easily accepted as an account number.
12 // - E-mail usually won't line-break if there's no punctuation to break at.
13 // - Doubleclicking selects the whole number as one word if it's all alphanumeric.
15 #ifndef BITCOIN_BASE58_H
16 #define BITCOIN_BASE58_H
23 static const char* pszBase58 = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
25 // Encode a byte sequence as a base58-encoded string
26 inline std::string EncodeBase58(const unsigned char* pbegin, const unsigned char* pend)
32 // Convert big endian data to little endian
33 // Extra zero at the end make sure bignum will interpret as a positive number
34 std::vector<unsigned char> vchTmp(pend-pbegin+1, 0);
35 reverse_copy(pbegin, pend, vchTmp.begin());
37 // Convert little endian data to bignum
41 // Convert bignum to std::string
43 // Expected size increase from base58 conversion is approximately 137%
44 // use 138% to be safe
45 str.reserve((pend - pbegin) * 138 / 100 + 1);
50 if (!BN_div(&dv, &rem, &bn, &bn58, pctx))
51 throw bignum_error("EncodeBase58 : BN_div failed");
53 unsigned int c = rem.getulong();
57 // Leading zeroes encoded as base58 zeros
58 for (const unsigned char* p = pbegin; p < pend && *p == 0; p++)
61 // Convert little endian std::string to big endian
62 reverse(str.begin(), str.end());
66 // Encode a byte vector as a base58-encoded string
67 inline std::string EncodeBase58(const std::vector<unsigned char>& vch)
69 return EncodeBase58(&vch[0], &vch[0] + vch.size());
72 // Decode a base58-encoded string psz into byte vector vchRet
73 // returns true if decoding is succesful
74 inline bool DecodeBase58(const char* psz, std::vector<unsigned char>& vchRet)
84 // Convert big endian string to bignum
85 for (const char* p = psz; *p; p++)
87 const char* p1 = strchr(pszBase58, *p);
96 bnChar.setulong(p1 - pszBase58);
97 if (!BN_mul(&bn, &bn, &bn58, pctx))
98 throw bignum_error("DecodeBase58 : BN_mul failed");
102 // Get bignum as little endian data
103 std::vector<unsigned char> vchTmp = bn.getvch();
105 // Trim off sign byte if present
106 if (vchTmp.size() >= 2 && vchTmp.end()[-1] == 0 && vchTmp.end()[-2] >= 0x80)
107 vchTmp.erase(vchTmp.end()-1);
109 // Restore leading zeros
110 int nLeadingZeros = 0;
111 for (const char* p = psz; *p == pszBase58[0]; p++)
113 vchRet.assign(nLeadingZeros + vchTmp.size(), 0);
115 // Convert little endian data to big endian
116 reverse_copy(vchTmp.begin(), vchTmp.end(), vchRet.end() - vchTmp.size());
120 // Decode a base58-encoded string str into byte vector vchRet
121 // returns true if decoding is succesful
122 inline bool DecodeBase58(const std::string& str, std::vector<unsigned char>& vchRet)
124 return DecodeBase58(str.c_str(), vchRet);
130 // Encode a byte vector to a base58-encoded string, including checksum
131 inline std::string EncodeBase58Check(const std::vector<unsigned char>& vchIn)
133 // add 4-byte hash check to the end
134 std::vector<unsigned char> vch(vchIn);
135 uint256 hash = Hash(vch.begin(), vch.end());
136 vch.insert(vch.end(), (unsigned char*)&hash, (unsigned char*)&hash + 4);
137 return EncodeBase58(vch);
140 // Decode a base58-encoded string psz that includes a checksum, into byte vector vchRet
141 // returns true if decoding is succesful
142 inline bool DecodeBase58Check(const char* psz, std::vector<unsigned char>& vchRet)
144 if (!DecodeBase58(psz, vchRet))
146 if (vchRet.size() < 4)
151 uint256 hash = Hash(vchRet.begin(), vchRet.end()-4);
152 if (memcmp(&hash, &vchRet.end()[-4], 4) != 0)
157 vchRet.resize(vchRet.size()-4);
161 // Decode a base58-encoded string str that includes a checksum, into byte vector vchRet
162 // returns true if decoding is succesful
163 inline bool DecodeBase58Check(const std::string& str, std::vector<unsigned char>& vchRet)
165 return DecodeBase58Check(str.c_str(), vchRet);
172 /** Base class for all base58-encoded data */
177 unsigned char nVersion;
179 // the actually encoded data
180 std::vector<unsigned char> vchData;
190 // zero the memory, as it may contain sensitive data
191 if (!vchData.empty())
192 memset(&vchData[0], 0, vchData.size());
195 void SetData(int nVersionIn, const void* pdata, size_t nSize)
197 nVersion = nVersionIn;
198 vchData.resize(nSize);
199 if (!vchData.empty())
200 memcpy(&vchData[0], pdata, nSize);
203 void SetData(int nVersionIn, const unsigned char *pbegin, const unsigned char *pend)
205 SetData(nVersionIn, (void*)pbegin, pend - pbegin);
209 bool SetString(const char* psz)
211 std::vector<unsigned char> vchTemp;
212 DecodeBase58Check(psz, vchTemp);
219 nVersion = vchTemp[0];
220 vchData.resize(vchTemp.size() - 1);
221 if (!vchData.empty())
222 memcpy(&vchData[0], &vchTemp[1], vchData.size());
223 memset(&vchTemp[0], 0, vchTemp.size());
227 bool SetString(const std::string& str)
229 return SetString(str.c_str());
232 std::string ToString() const
234 std::vector<unsigned char> vch(1, nVersion);
235 vch.insert(vch.end(), vchData.begin(), vchData.end());
236 return EncodeBase58Check(vch);
239 int CompareTo(const CBase58Data& b58) const
241 if (nVersion < b58.nVersion) return -1;
242 if (nVersion > b58.nVersion) return 1;
243 if (vchData < b58.vchData) return -1;
244 if (vchData > b58.vchData) return 1;
248 bool operator==(const CBase58Data& b58) const { return CompareTo(b58) == 0; }
249 bool operator<=(const CBase58Data& b58) const { return CompareTo(b58) <= 0; }
250 bool operator>=(const CBase58Data& b58) const { return CompareTo(b58) >= 0; }
251 bool operator< (const CBase58Data& b58) const { return CompareTo(b58) < 0; }
252 bool operator> (const CBase58Data& b58) const { return CompareTo(b58) > 0; }
255 /** base58-encoded bitcoin addresses.
256 * Public-key-hash-addresses have version 0 (or 111 testnet).
257 * The data vector contains RIPEMD160(SHA256(pubkey)), where pubkey is the serialized public key.
258 * Script-hash-addresses have version 5 (or 196 testnet).
259 * The data vector contains RIPEMD160(SHA256(cscript)), where cscript is the serialized redemption script.
261 class CBitcoinAddress : public CBase58Data
268 PUBKEY_ADDRESS_TEST = 111,
269 SCRIPT_ADDRESS_TEST = 196,
272 bool SetHash160(const uint160& hash160)
274 SetData(fTestNet ? PUBKEY_ADDRESS_TEST : PUBKEY_ADDRESS, &hash160, 20);
278 void SetPubKey(const std::vector<unsigned char>& vchPubKey)
280 SetHash160(Hash160(vchPubKey));
283 bool SetScriptHash160(const uint160& hash160)
285 SetData(fTestNet ? SCRIPT_ADDRESS_TEST : SCRIPT_ADDRESS, &hash160, 20);
291 unsigned int nExpectedSize = 20;
292 bool fExpectTestNet = false;
296 nExpectedSize = 20; // Hash of public key
297 fExpectTestNet = false;
300 nExpectedSize = 20; // Hash of CScript
301 fExpectTestNet = false;
304 case PUBKEY_ADDRESS_TEST:
306 fExpectTestNet = true;
308 case SCRIPT_ADDRESS_TEST:
310 fExpectTestNet = true;
316 return fExpectTestNet == fTestNet && vchData.size() == nExpectedSize;
318 bool IsScript() const
323 return nVersion == SCRIPT_ADDRESS_TEST;
324 return nVersion == SCRIPT_ADDRESS;
331 CBitcoinAddress(uint160 hash160In)
333 SetHash160(hash160In);
336 CBitcoinAddress(const std::vector<unsigned char>& vchPubKey)
338 SetPubKey(vchPubKey);
341 CBitcoinAddress(const std::string& strAddress)
343 SetString(strAddress);
346 CBitcoinAddress(const char* pszAddress)
348 SetString(pszAddress);
351 uint160 GetHash160() const
353 assert(vchData.size() == 20);
355 memcpy(&hash160, &vchData[0], 20);
360 /** A base58-encoded secret key */
361 class CBitcoinSecret : public CBase58Data
364 void SetSecret(const CSecret& vchSecret, bool fCompressed)
366 assert(vchSecret.size() == 32);
367 SetData(fTestNet ? 239 : 128, &vchSecret[0], vchSecret.size());
369 vchData.push_back(1);
372 CSecret GetSecret(bool &fCompressedOut)
375 vchSecret.resize(32);
376 memcpy(&vchSecret[0], &vchData[0], 32);
377 fCompressedOut = vchData.size() == 33;
383 bool fExpectTestNet = false;
390 fExpectTestNet = true;
396 return fExpectTestNet == fTestNet && (vchData.size() == 32 || (vchData.size() == 33 && vchData[32] == 1));
399 bool SetString(const char* pszSecret)
401 return CBase58Data::SetString(pszSecret) && IsValid();
404 bool SetString(const std::string& strSecret)
406 return SetString(strSecret.c_str());
409 CBitcoinSecret(const CSecret& vchSecret, bool fCompressed)
411 SetSecret(vchSecret, fCompressed);