Golang Int.Uint64方法代码示例

func main() {

	var iban string
	var r, s, t, st []string
	u := new(big.Int)
	v := new(big.Int)
	w := new(big.Int)

	iban = "GB82 TEST 1234 5698 7654 32"
	r = strings.Split(iban, " ")
	s = strings.Split(r[0], "")
	t = strings.Split(r[1], "")

	st = []string{strconv.Itoa(sCode[t[0]]),
		strconv.Itoa(sCode[t[1]]),
		strconv.Itoa(sCode[t[2]]),
		strconv.Itoa(sCode[t[3]]),
		strings.Join(r[2:6], ""),
		strconv.Itoa(sCode[s[0]]),
		strconv.Itoa(sCode[s[1]]),
		strings.Join(s[2:4], ""),
	}

	u.SetString(strings.Join(st, ""), 10)
	v.SetInt64(97)
	w.Mod(u, v)

	if w.Uint64() == 1 && lCode[strings.Join(s[0:2], "")] == len(strings.Join(r, "")) {
		fmt.Printf("IBAN %s looks good!\n", iban)
	} else {
		fmt.Printf("IBAN %s looks wrong!\n", iban)
	}
}

func (dag *Dagger) Node(L uint64, i uint64) *big.Int {
	if L == i {
		return dag.hash
	}

	var m *big.Int
	if L == 9 {
		m = big.NewInt(16)
	} else {
		m = big.NewInt(3)
	}

	sha := sha3.NewKeccak256()
	sha.Reset()
	d := sha3.NewKeccak256()
	b := new(big.Int)
	ret := new(big.Int)

	for k := 0; k < int(m.Uint64()); k++ {
		d.Reset()
		d.Write(dag.hash.Bytes())
		d.Write(dag.xn.Bytes())
		d.Write(big.NewInt(int64(L)).Bytes())
		d.Write(big.NewInt(int64(i)).Bytes())
		d.Write(big.NewInt(int64(k)).Bytes())

		b.SetBytes(Sum(d))
		pk := b.Uint64() & ((1 << ((L - 1) * 3)) - 1)
		sha.Write(dag.Node(L-1, pk).Bytes())
	}

	ret.SetBytes(Sum(sha))

	return ret
}

func ecrecoverFunc(in []byte) []byte {
	// "in" is (hash, v, r, s), each 32 bytes
	// but for ecrecover we want (r, s, v)
	if len(in) < ecRecoverInputLength {
		return nil
	}

	// Treat V as a 256bit integer
	v := new(big.Int).Sub(common.Bytes2Big(in[32:64]), big.NewInt(27))
	// Ethereum requires V to be either 0 or 1 => (27 || 28)
	if !(v.Cmp(Zero) == 0 || v.Cmp(One) == 0) {
		return nil
	}

	// v needs to be moved to the end
	rsv := append(in[64:128], byte(v.Uint64()))
	pubKey, err := crypto.Ecrecover(in[:32], rsv)
	// make sure the public key is a valid one
	if err != nil {
		glog.V(logger.Error).Infof("EC RECOVER FAIL: ", err)
		return nil
	}

	// the first byte of pubkey is bitcoin heritage
	return common.LeftPadBytes(crypto.Sha3(pubKey[1:])[12:], 32)
}

func TestJWKThumbprint(t *testing.T) {
	// Key example from RFC 7638
	const base64N = "0vx7agoebGcQSuuPiLJXZptN9nndrQmbXEps2aiAFbWhM78LhWx4cbbfAAt" +
		"VT86zwu1RK7aPFFxuhDR1L6tSoc_BJECPebWKRXjBZCiFV4n3oknjhMstn6" +
		"4tZ_2W-5JsGY4Hc5n9yBXArwl93lqt7_RN5w6Cf0h4QyQ5v-65YGjQR0_FD" +
		"W2QvzqY368QQMicAtaSqzs8KJZgnYb9c7d0zgdAZHzu6qMQvRL5hajrn1n9" +
		"1CbOpbISD08qNLyrdkt-bFTWhAI4vMQFh6WeZu0fM4lFd2NcRwr3XPksINH" +
		"aQ-G_xBniIqbw0Ls1jF44-csFCur-kEgU8awapJzKnqDKgw"
	const base64E = "AQAB"
	const expected = "NzbLsXh8uDCcd-6MNwXF4W_7noWXFZAfHkxZsRGC9Xs"

	bytes, err := base64.RawURLEncoding.DecodeString(base64N)
	if err != nil {
		t.Fatalf("Error parsing example key N: %v", err)
	}
	n := new(big.Int).SetBytes(bytes)

	bytes, err = base64.RawURLEncoding.DecodeString(base64E)
	if err != nil {
		t.Fatalf("Error parsing example key E: %v", err)
	}
	e := new(big.Int).SetBytes(bytes)

	pub := &rsa.PublicKey{N: n, E: int(e.Uint64())}
	th := JWKThumbprint(pub)
	if th != expected {
		t.Errorf("th = %q; want %q", th, expected)
	}
}

// Create a new UniformDH instance
func New() *UniformDH {
	udh := &UniformDH{}

	privStr := make([]byte, groupLen)
	// To pick a private UniformDH key, we pick a random 1536-bit number,
	// and make it even by setting its low bit to 0. Let x be that private
	// key, and X = g^x (mod p).
	rand.Read(privStr)
	udh.priv.SetBytes(privStr)

	/// XXX: is setting this bit *and* modulo 2 necessary?
	udh.priv.SetBit(&udh.priv, 0, 0)

	// When someone sends her public key to the other party, she randomly
	// decides whether to send X or p-X. This makes the public key
	// negligibly different from a uniform 1536-bit string
	flip := new(big.Int).Mod(&udh.priv, big.NewInt(2))
	udh.priv.Sub(&udh.priv, flip)

	udh.pub.Exp(big.NewInt(g), &udh.priv, &mod)

	if flip.Uint64() == 1 {
		udh.pub.Sub(&mod, &udh.pub)
	}

	/// XXX: handle erroneous situations better
	if udh.priv.BitLen() > intSize {
		panic("int too large")
	}

	return udh
}

func (dag *Dagger) Eval(N *big.Int) *big.Int {
	pow := common.BigPow(2, 26)
	dag.xn = pow.Div(N, pow)

	sha := sha3.NewKeccak256()
	sha.Reset()
	ret := new(big.Int)

	for k := 0; k < 4; k++ {
		d := sha3.NewKeccak256()
		b := new(big.Int)

		d.Reset()
		d.Write(dag.hash.Bytes())
		d.Write(dag.xn.Bytes())
		d.Write(N.Bytes())
		d.Write(big.NewInt(int64(k)).Bytes())

		b.SetBytes(Sum(d))
		pk := (b.Uint64() & 0x1ffffff)

		sha.Write(dag.Node(9, pk).Bytes())
	}

	return ret.SetBytes(Sum(sha))
}

// encodeBlock fills the dst buffer with the encoding of src.
// It is assumed the buffers are appropriately sized, and no
// bounds checks are performed.  In particular, the dst buffer will
// be zero-padded from right to left in all remaining bytes.
func (enc *Encoding) encodeBlock(dst, src []byte) {

	// Interpret the block as a big-endian number (Go's default)
	num := new(big.Int).SetBytes(src)
	rem := new(big.Int)
	quo := new(big.Int)

	encodedLen := enc.EncodedLen(len(src))

	// Shift over the given number of extra Bits, so that all of our
	// wasted bits are on the right.
	num = num.Lsh(num, enc.extraBits(len(src), encodedLen))

	p := encodedLen - 1

	for num.Sign() != 0 {
		num, rem = quo.QuoRem(num, enc.baseBig, rem)
		dst[p] = enc.encode[rem.Uint64()]
		p--
	}

	// Pad the remainder of the buffer with 0s
	for p >= 0 {
		dst[p] = enc.encode[0]
		p--
	}
}

func TestModAdc(t *testing.T) {
	A := new(big.Int)
	B := new(big.Int)
	C := new(big.Int)
	Carry := new(big.Int)
	Mask := new(big.Int)
	for _, a := range numbers {
		A.SetUint64(a)
		for _, b := range numbers {
			B.SetUint64(b)
			for width := uint8(1); width < 64; width++ {
				carry := b
				c := mod_adc(a, width, &carry)
				C.Add(A, B)
				Carry.Rsh(C, uint(width))
				expectedCarry := Carry.Uint64()
				Mask.SetUint64(uint64(1)<<width - 1)
				C.And(C, Mask)
				expected := C.Uint64()
				if c != expected || expectedCarry != carry {
					t.Fatalf("adc(%d,%d,%d): Expecting %d carry %d but got %d carry %d", a, b, width, expected, expectedCarry, c, carry)
				}
			}
		}
	}
}

func ecrecoverFunc(in []byte) []byte {
	in = common.RightPadBytes(in, 128)
	// "in" is (hash, v, r, s), each 32 bytes
	// but for ecrecover we want (r, s, v)

	r := common.BytesToBig(in[64:96])
	s := common.BytesToBig(in[96:128])
	// Treat V as a 256bit integer
	vbig := common.Bytes2Big(in[32:64])
	v := byte(vbig.Uint64())

	if !crypto.ValidateSignatureValues(v, r, s) {
		glog.V(logger.Error).Infof("EC RECOVER FAIL: v, r or s value invalid")
		return nil
	}

	// v needs to be at the end and normalized for libsecp256k1
	vbignormal := new(big.Int).Sub(vbig, big.NewInt(27))
	vnormal := byte(vbignormal.Uint64())
	rsv := append(in[64:128], vnormal)
	pubKey, err := crypto.Ecrecover(in[:32], rsv)
	// make sure the public key is a valid one
	if err != nil {
		glog.V(logger.Error).Infof("EC RECOVER FAIL: ", err)
		return nil
	}

	// the first byte of pubkey is bitcoin heritage
	return common.LeftPadBytes(crypto.Sha3(pubKey[1:])[12:], 32)
}

func getData(data []byte, start, size *big.Int) []byte {
	dlen := big.NewInt(int64(len(data)))

	s := common.BigMin(start, dlen)
	e := common.BigMin(new(big.Int).Add(s, size), dlen)
	return common.RightPadBytes(data[s.Uint64():e.Uint64()], int(size.Uint64()))
}

func (d *DatasourceDerive) CalculatePdpPrep(newValue string, interval float64) (float64, error) {
	if float64(d.Heartbeat) < interval {
		d.LastValue = Undefined
	}

	rate := math.NaN()
	newPdp := math.NaN()
	if newValue != Undefined && float64(d.Heartbeat) >= interval {
		newInt := new(big.Int)
		_, err := fmt.Sscan(newValue, newInt)
		if err != nil {
			return math.NaN(), errors.Errorf("not a simple signed integer: %s", newValue)
		}
		if d.LastValue != "U" {
			prevInt := new(big.Int)
			_, err := fmt.Sscan(d.LastValue, prevInt)
			if err != nil {
				return math.NaN(), errors.Wrap(err, 0)
			}
			diff := new(big.Int)
			diff.Sub(newInt, prevInt)

			newPdp = float64(diff.Uint64())
			rate = newPdp / interval
		}
	}

	if !d.checkRateBounds(rate) {
		newPdp = math.NaN()
	}

	d.LastValue = newValue

	return newPdp, nil
}

// Encode58 base58 encodes the input.
func Encode58(inp []byte) string {
	num := new(big.Int).SetBytes(inp)
	buf := make([]byte, 0, len(inp))
	base := big.NewInt(int64(58))
	rem := new(big.Int)
	quo := new(big.Int)

	for num.Sign() != 0 {
		num, rem = quo.QuoRem(num, base, rem)
		c := alphabet[rem.Uint64()]
		buf = append(buf, c)
	}

	// Pad leading zeros...
	for _, c := range inp {
		if c == 0x0 {
			buf = append(buf, alphabet[0])
		} else {
			// Stop adding padding after the first nonzero byte.
			break
		}
	}
	reverseBuf(buf)

	return string(buf)
}

// SmallPrimeTest determins if N is a small prime
// or divisible by a small prime.
func SmallPrimeTest(N *big.Int) int {
	if N.Sign() <= 0 {
		panic("SmallPrimeTest for positive integers only")
	}
	if N.BitLen() <= 10 {
		n := uint16(N.Uint64())
		i := sort.Search(len(primes10), func(i int) bool {
			return primes10[i] >= n
		})
		if i >= len(primes10) || n != primes10[i] {
			return IsComposite
		}
		return IsPrime
	}
	// quick test for N even
	if N.Bits()[0]&1 == 0 {
		return IsComposite
	}
	// compare several small gcds for efficency
	z := new(big.Int)
	if z.GCD(nil, nil, N, prodPrimes10A).Cmp(one) == 1 {
		return IsComposite
	}
	if z.GCD(nil, nil, N, prodPrimes10B).Cmp(one) == 1 {
		return IsComposite
	}
	if z.GCD(nil, nil, N, prodPrimes10C).Cmp(one) == 1 {
		return IsComposite
	}
	if z.GCD(nil, nil, N, prodPrimes10D).Cmp(one) == 1 {
		return IsComposite
	}
	return Undetermined
}

func jump(mapping map[uint64]uint64, destinations map[uint64]struct{}, contract *Contract, to *big.Int) (uint64, error) {
	if !validDest(destinations, to) {
		nop := contract.GetOp(to.Uint64())
		return 0, fmt.Errorf("invalid jump destination (%v) %v", nop, to)
	}

	return mapping[to.Uint64()], nil
}

/*	solution:
	Will rapresent the moves as R=right, D=Down....
	In any grid of size N, we need N moves of each (R,D) (total 2N moves)
		ex for the 2x2 grid we have RRDD,RDRD,RDDR,DRRD,DRDR,DDRR (6 moves)
	If we arbitrary choose N of one direction first and fill the rest
	with other direction,
	the problem becomes a combination problem for N choices out of 2N
	so we could use the C(n,k) = n!/(k!(n-k)!) for the answer
	where n = 2N and k=N
*/
func Euler015(N int) uint64 {
	n, k := (2 * N), N

	num := utils.Fact(n)
	den := new(big.Int).Mul(utils.Fact(k), utils.Fact(n-k))
	res := new(big.Int).Div(num, den)

	return res.Uint64()
}