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 COPYING or http://www.opensource.org/licenses/mit-license.php.
5 #ifndef BITCOIN_BIGNUM_H
6 #define BITCOIN_BIGNUM_H
10 #include <openssl/bn.h>
12 #include "util.h" // for uint64
14 /** Errors thrown by the bignum class */
15 class bignum_error : public std::runtime_error
18 explicit bignum_error(const std::string& str) : std::runtime_error(str) {}
22 /** RAII encapsulated BN_CTX (OpenSSL bignum context) */
27 BN_CTX* operator=(BN_CTX* pnew) { return pctx = pnew; }
34 throw bignum_error("CAutoBN_CTX : BN_CTX_new() returned NULL");
43 operator BN_CTX*() { return pctx; }
44 BN_CTX& operator*() { return *pctx; }
45 BN_CTX** operator&() { return &pctx; }
46 bool operator!() { return (pctx == NULL); }
50 /** C++ wrapper for BIGNUM (OpenSSL bignum) */
51 class CBigNum : public BIGNUM
59 CBigNum(const CBigNum& b)
62 if (!BN_copy(this, &b))
65 throw bignum_error("CBigNum::CBigNum(const CBigNum&) : BN_copy failed");
69 CBigNum& operator=(const CBigNum& b)
71 if (!BN_copy(this, &b))
72 throw bignum_error("CBigNum::operator= : BN_copy failed");
81 //CBigNum(char n) is not portable. Use 'signed char' or 'unsigned char'.
82 CBigNum(signed char n) { BN_init(this); if (n >= 0) setulong(n); else setint64(n); }
83 CBigNum(short n) { BN_init(this); if (n >= 0) setulong(n); else setint64(n); }
84 CBigNum(int n) { BN_init(this); if (n >= 0) setulong(n); else setint64(n); }
85 CBigNum(long n) { BN_init(this); if (n >= 0) setulong(n); else setint64(n); }
86 CBigNum(int64 n) { BN_init(this); setint64(n); }
87 CBigNum(unsigned char n) { BN_init(this); setulong(n); }
88 CBigNum(unsigned short n) { BN_init(this); setulong(n); }
89 CBigNum(unsigned int n) { BN_init(this); setulong(n); }
90 CBigNum(unsigned long n) { BN_init(this); setulong(n); }
91 CBigNum(uint64 n) { BN_init(this); setuint64(n); }
92 explicit CBigNum(uint256 n) { BN_init(this); setuint256(n); }
94 explicit CBigNum(const std::vector<unsigned char>& vch)
100 void setulong(unsigned long n)
102 if (!BN_set_word(this, n))
103 throw bignum_error("CBigNum conversion from unsigned long : BN_set_word failed");
106 unsigned long getulong() const
108 return BN_get_word(this);
111 unsigned int getuint() const
113 return BN_get_word(this);
118 unsigned long n = BN_get_word(this);
119 if (!BN_is_negative(this))
120 return (n > (unsigned long)std::numeric_limits<int>::max() ? std::numeric_limits<int>::max() : n);
122 return (n > (unsigned long)std::numeric_limits<int>::max() ? std::numeric_limits<int>::min() : -(int)n);
125 void setint64(int64 n)
127 unsigned char pch[sizeof(n) + 6];
128 unsigned char* p = pch + 4;
129 bool fNegative = false;
135 bool fLeadingZeroes = true;
136 for (int i = 0; i < 8; i++)
138 unsigned char c = (n >> 56) & 0xff;
145 *p++ = (fNegative ? 0x80 : 0);
148 fLeadingZeroes = false;
152 unsigned int nSize = p - (pch + 4);
153 pch[0] = (nSize >> 24) & 0xff;
154 pch[1] = (nSize >> 16) & 0xff;
155 pch[2] = (nSize >> 8) & 0xff;
156 pch[3] = (nSize) & 0xff;
157 BN_mpi2bn(pch, p - pch, this);
160 void setuint64(uint64 n)
162 unsigned char pch[sizeof(n) + 6];
163 unsigned char* p = pch + 4;
164 bool fLeadingZeroes = true;
165 for (int i = 0; i < 8; i++)
167 unsigned char c = (n >> 56) & 0xff;
175 fLeadingZeroes = false;
179 unsigned int nSize = p - (pch + 4);
180 pch[0] = (nSize >> 24) & 0xff;
181 pch[1] = (nSize >> 16) & 0xff;
182 pch[2] = (nSize >> 8) & 0xff;
183 pch[3] = (nSize) & 0xff;
184 BN_mpi2bn(pch, p - pch, this);
189 unsigned int nSize = BN_bn2mpi(this, NULL);
192 std::vector<unsigned char> vch(nSize);
193 BN_bn2mpi(this, &vch[0]);
197 for (int i = 0, j = vch.size()-1; i < sizeof(n) && j >= 4; i++, j--)
198 ((unsigned char*)&n)[i] = vch[j];
202 void setuint256(uint256 n)
204 unsigned char pch[sizeof(n) + 6];
205 unsigned char* p = pch + 4;
206 bool fLeadingZeroes = true;
207 unsigned char* pbegin = (unsigned char*)&n;
208 unsigned char* psrc = pbegin + sizeof(n);
209 while (psrc != pbegin)
211 unsigned char c = *(--psrc);
218 fLeadingZeroes = false;
222 unsigned int nSize = p - (pch + 4);
223 pch[0] = (nSize >> 24) & 0xff;
224 pch[1] = (nSize >> 16) & 0xff;
225 pch[2] = (nSize >> 8) & 0xff;
226 pch[3] = (nSize >> 0) & 0xff;
227 BN_mpi2bn(pch, p - pch, this);
232 unsigned int nSize = BN_bn2mpi(this, NULL);
235 std::vector<unsigned char> vch(nSize);
236 BN_bn2mpi(this, &vch[0]);
240 for (unsigned int i = 0, j = vch.size()-1; i < sizeof(n) && j >= 4; i++, j--)
241 ((unsigned char*)&n)[i] = vch[j];
245 void setvch(const std::vector<unsigned char>& vch)
247 std::vector<unsigned char> vch2(vch.size() + 4);
248 unsigned int nSize = vch.size();
249 // BIGNUM's byte stream format expects 4 bytes of
250 // big endian size data info at the front
251 vch2[0] = (nSize >> 24) & 0xff;
252 vch2[1] = (nSize >> 16) & 0xff;
253 vch2[2] = (nSize >> 8) & 0xff;
254 vch2[3] = (nSize >> 0) & 0xff;
255 // swap data to big endian
256 reverse_copy(vch.begin(), vch.end(), vch2.begin() + 4);
257 BN_mpi2bn(&vch2[0], vch2.size(), this);
260 std::vector<unsigned char> getvch() const
262 unsigned int nSize = BN_bn2mpi(this, NULL);
264 return std::vector<unsigned char>();
265 std::vector<unsigned char> vch(nSize);
266 BN_bn2mpi(this, &vch[0]);
267 vch.erase(vch.begin(), vch.begin() + 4);
268 reverse(vch.begin(), vch.end());
272 CBigNum& SetCompact(unsigned int nCompact)
274 unsigned int nSize = nCompact >> 24;
275 std::vector<unsigned char> vch(4 + nSize);
277 if (nSize >= 1) vch[4] = (nCompact >> 16) & 0xff;
278 if (nSize >= 2) vch[5] = (nCompact >> 8) & 0xff;
279 if (nSize >= 3) vch[6] = (nCompact >> 0) & 0xff;
280 BN_mpi2bn(&vch[0], vch.size(), this);
284 unsigned int GetCompact() const
286 unsigned int nSize = BN_bn2mpi(this, NULL);
287 std::vector<unsigned char> vch(nSize);
289 BN_bn2mpi(this, &vch[0]);
290 unsigned int nCompact = nSize << 24;
291 if (nSize >= 1) nCompact |= (vch[4] << 16);
292 if (nSize >= 2) nCompact |= (vch[5] << 8);
293 if (nSize >= 3) nCompact |= (vch[6] << 0);
297 void SetHex(const std::string& str)
300 const char* psz = str.c_str();
301 while (isspace(*psz))
303 bool fNegative = false;
309 if (psz[0] == '0' && tolower(psz[1]) == 'x')
311 while (isspace(*psz))
314 // hex string to bignum
315 static signed char phexdigit[256] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,1,2,3,4,5,6,7,8,9,0,0,0,0,0,0, 0,0xa,0xb,0xc,0xd,0xe,0xf,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0xa,0xb,0xc,0xd,0xe,0xf,0,0,0,0,0,0,0,0,0 };
317 while (isxdigit(*psz))
320 int n = phexdigit[(unsigned char)*psz++];
327 std::string ToString(int nBase=10) const
330 CBigNum bnBase = nBase;
334 BN_set_negative(&bn, false);
337 if (BN_cmp(&bn, &bn0) == 0)
339 while (BN_cmp(&bn, &bn0) > 0)
341 if (!BN_div(&dv, &rem, &bn, &bnBase, pctx))
342 throw bignum_error("CBigNum::ToString() : BN_div failed");
344 unsigned int c = rem.getulong();
345 str += "0123456789abcdef"[c];
347 if (BN_is_negative(this))
349 reverse(str.begin(), str.end());
353 std::string GetHex() const
358 unsigned int GetSerializeSize(int nType=0, int nVersion=PROTOCOL_VERSION) const
360 return ::GetSerializeSize(getvch(), nType, nVersion);
363 template<typename Stream>
364 void Serialize(Stream& s, int nType=0, int nVersion=PROTOCOL_VERSION) const
366 ::Serialize(s, getvch(), nType, nVersion);
369 template<typename Stream>
370 void Unserialize(Stream& s, int nType=0, int nVersion=PROTOCOL_VERSION)
372 std::vector<unsigned char> vch;
373 ::Unserialize(s, vch, nType, nVersion);
378 bool operator!() const
380 return BN_is_zero(this);
383 CBigNum& operator+=(const CBigNum& b)
385 if (!BN_add(this, this, &b))
386 throw bignum_error("CBigNum::operator+= : BN_add failed");
390 CBigNum& operator-=(const CBigNum& b)
396 CBigNum& operator*=(const CBigNum& b)
399 if (!BN_mul(this, this, &b, pctx))
400 throw bignum_error("CBigNum::operator*= : BN_mul failed");
404 CBigNum& operator/=(const CBigNum& b)
410 CBigNum& operator%=(const CBigNum& b)
416 CBigNum& operator<<=(unsigned int shift)
418 if (!BN_lshift(this, this, shift))
419 throw bignum_error("CBigNum:operator<<= : BN_lshift failed");
423 CBigNum& operator>>=(unsigned int shift)
425 // Note: BN_rshift segfaults on 64-bit if 2^shift is greater than the number
426 // if built on ubuntu 9.04 or 9.10, probably depends on version of openssl
429 if (BN_cmp(&a, this) > 0)
435 if (!BN_rshift(this, this, shift))
436 throw bignum_error("CBigNum:operator>>= : BN_rshift failed");
441 CBigNum& operator++()
444 if (!BN_add(this, this, BN_value_one()))
445 throw bignum_error("CBigNum::operator++ : BN_add failed");
449 const CBigNum operator++(int)
452 const CBigNum ret = *this;
457 CBigNum& operator--()
461 if (!BN_sub(&r, this, BN_value_one()))
462 throw bignum_error("CBigNum::operator-- : BN_sub failed");
467 const CBigNum operator--(int)
470 const CBigNum ret = *this;
476 friend inline const CBigNum operator-(const CBigNum& a, const CBigNum& b);
477 friend inline const CBigNum operator/(const CBigNum& a, const CBigNum& b);
478 friend inline const CBigNum operator%(const CBigNum& a, const CBigNum& b);
483 inline const CBigNum operator+(const CBigNum& a, const CBigNum& b)
486 if (!BN_add(&r, &a, &b))
487 throw bignum_error("CBigNum::operator+ : BN_add failed");
491 inline const CBigNum operator-(const CBigNum& a, const CBigNum& b)
494 if (!BN_sub(&r, &a, &b))
495 throw bignum_error("CBigNum::operator- : BN_sub failed");
499 inline const CBigNum operator-(const CBigNum& a)
502 BN_set_negative(&r, !BN_is_negative(&r));
506 inline const CBigNum operator*(const CBigNum& a, const CBigNum& b)
510 if (!BN_mul(&r, &a, &b, pctx))
511 throw bignum_error("CBigNum::operator* : BN_mul failed");
515 inline const CBigNum operator/(const CBigNum& a, const CBigNum& b)
519 if (!BN_div(&r, NULL, &a, &b, pctx))
520 throw bignum_error("CBigNum::operator/ : BN_div failed");
524 inline const CBigNum operator%(const CBigNum& a, const CBigNum& b)
528 if (!BN_mod(&r, &a, &b, pctx))
529 throw bignum_error("CBigNum::operator% : BN_div failed");
533 inline const CBigNum operator<<(const CBigNum& a, unsigned int shift)
536 if (!BN_lshift(&r, &a, shift))
537 throw bignum_error("CBigNum:operator<< : BN_lshift failed");
541 inline const CBigNum operator>>(const CBigNum& a, unsigned int shift)
548 inline bool operator==(const CBigNum& a, const CBigNum& b) { return (BN_cmp(&a, &b) == 0); }
549 inline bool operator!=(const CBigNum& a, const CBigNum& b) { return (BN_cmp(&a, &b) != 0); }
550 inline bool operator<=(const CBigNum& a, const CBigNum& b) { return (BN_cmp(&a, &b) <= 0); }
551 inline bool operator>=(const CBigNum& a, const CBigNum& b) { return (BN_cmp(&a, &b) >= 0); }
552 inline bool operator<(const CBigNum& a, const CBigNum& b) { return (BN_cmp(&a, &b) < 0); }
553 inline bool operator>(const CBigNum& a, const CBigNum& b) { return (BN_cmp(&a, &b) > 0); }