util

Documentation

Overview

Package common contains various helper functions.

Index

• Constants
• Variables
• func AllZero(b []byte) bool
• func BigMax(x, y *big.Int) *big.Int
• func BigMin(x, y *big.Int) *big.Int
• func BigPow(a, b int64) *big.Int
• func BigUint64(v *big.Int) (uint64, bool)
• func Bool2Bytes(b bool) []byte
• func Byte(bigint *big.Int, padlength, n int) byte
• func Bytes2Hex(d []byte) string
• func BytesEqual(a, b []byte) bool
• func BytesToString(data []byte) string
• func CopyBytes(b []byte) (copiedBytes []byte)
• func CreateDirIfNotExist(dir string) error
• func Decrypt(cryptograph string, passphrase string) (string, error)
• func DecryptBytes(encryptedJSON []byte, passphrase []byte) ([]byte, error)
• func Encrypt(raw string, passphrase string) (string, error)
• func EncryptBytes(raw []byte, passphrase []byte) ([]byte, error)
• func Exp(base, exponent *big.Int) *big.Int
• func FromHex(s string) []byte
• func Hash(size int, data ...[]byte) []byte
• func Hash256(data ...[]byte) []byte
• func Hex2Bytes(str string) []byte
• func Hex2BytesFixed(str string, flen int) []byte
• func Hex32ToBytes(s string) [32]byte
• func Hex64ToBytes(s string) [64]byte
• func HexToBytes(s string) []byte
• func Int2Bytes(i int64) []byte
• func Int64ToBytes(i int64) []byte
• func JoinBytes(data ...[]byte) []byte
• func LeftPadBytes(slice []byte, l int) []byte
• func Max(x, y uint64) uint64
• func Min(x, y uint64) uint64
• func PaddedBigBytes(bigint *big.Int, n int) []byte
• func ReadBits(bigint *big.Int, buf []byte)
• func ReverseBytes(str []byte) (result []byte)
• func RightPadBytes(slice []byte, l int) []byte
• func S256(x *big.Int) *big.Int
• func SafeAdd(x, y uint64) (uint64, bool)
• func SafeMul(x, y uint64) (uint64, bool)
• func SafeSub(x, y uint64) (uint64, bool)
• func String2Bytes(s string) []byte
• func StringToBigInt(str *string) (*big.Int, error)
• func ToHex(b []byte) string
• func ToIndentString(v interface{}) string
• func ToString(v interface{}) string
• func ToWordSize(size uint64) uint64
• func TrimBuffToString(bytes []byte) string
• func TrimQuotes(s string) string
• func U256(x *big.Int) *big.Int
• func Uint64ToBytes(i uint64) []byte

Constants

const (
	// StandardScryptN is the N parameter of Scrypt encryption algorithm, using 256MB
	// memory and taking approximately 1s CPU time on a modern processor.
	StandardScryptN = 1 << 18

	// StandardScryptP is the P parameter of Scrypt encryption algorithm, using 256MB
	// memory and taking approximately 1s CPU time on a modern processor.
	StandardScryptP = 1
)

const (
	MaxUint64 = uint64(1<<64 - 1)

	// number of bits in a big.Word
	WordBits = 32 << (uint64(^big.Word(0)) >> 63)
	// number of bytes in a big.Word
	WordBytes = WordBits / 8
	// number of bytes in a vm word
	WordSize = 32
)

Variables

var (
	Big0   = big.NewInt(0)
	Big1   = big.NewInt(1)
	Big2   = big.NewInt(2)
	Big10  = big.NewInt(10)
	Big31  = big.NewInt(31)
	Big32  = big.NewInt(32)
	Big256 = big.NewInt(256)
	Big257 = big.NewInt(257)

	Tt255   = BigPow(2, 255)
	Tt256   = BigPow(2, 256)
	Tt256m1 = new(big.Int).Sub(Tt256, big.NewInt(1))
)

Functions

func AllZero

func AllZero(b []byte) bool

func BigMax

func BigMax(x, y *big.Int) *big.Int

BigMax returns the larger of x or y.

func BigMin

func BigMin(x, y *big.Int) *big.Int

BigMin returns the smaller of x or y.

func BigPow

func BigPow(a, b int64) *big.Int

BigPow returns a ** b as a big integer.

func BigUint64

func BigUint64(v *big.Int) (uint64, bool)

BigUint64 returns the integer casted to a uint64 and returns whether it overflowed in the process.

func Bool2Bytes

func Bool2Bytes(b bool) []byte

func Byte

func Byte(bigint *big.Int, padlength, n int) byte

Byte returns the byte at position n, with the supplied padlength in Little-Endian encoding. n==0 returns the MSB Example: bigint '5', padlength 32, n=31 => 5

func Bytes2Hex

func Bytes2Hex(d []byte) string

Bytes2Hex returns the hexadecimal encoding of d.

func BytesEqual

func BytesEqual(a, b []byte) bool

func BytesToString

func BytesToString(data []byte) string

func CopyBytes

func CopyBytes(b []byte) (copiedBytes []byte)

CopyBytes returns an exact copy of the provided bytes.

func CreateDirIfNotExist

func CreateDirIfNotExist(dir string) error

CreateDirIfNotExist create given folder

func Decrypt

func Decrypt(cryptograph string, passphrase string) (string, error)

func DecryptBytes

func DecryptBytes(encryptedJSON []byte, passphrase []byte) ([]byte, error)

DecryptBytes decrypt raw json to raw

func Encrypt

func Encrypt(raw string, passphrase string) (string, error)

func EncryptBytes

func EncryptBytes(raw []byte, passphrase []byte) ([]byte, error)

EncryptBytes encrypts raw by passphrase to json binary

func Exp

func Exp(base, exponent *big.Int) *big.Int

Exp implements exponentiation by squaring. Exp returns a newly-allocated big integer and does not change base or exponent. The result is truncated to 256 bits.

func FromHex

func FromHex(s string) []byte

FromHex returns the bytes represented by the hexadecimal string s. s may be prefixed with "0x".

func Hash

func Hash(size int, data ...[]byte) []byte

func Hash256

func Hash256(data ...[]byte) []byte

func Hex2Bytes

func Hex2Bytes(str string) []byte

Hex2Bytes returns the bytes represented by the hexadecimal string str.

func Hex2BytesFixed

func Hex2BytesFixed(str string, flen int) []byte

Hex2BytesFixed returns bytes of a specified fixed length flen.

func Hex32ToBytes

func Hex32ToBytes(s string) [32]byte

func Hex64ToBytes

func Hex64ToBytes(s string) [64]byte

func HexToBytes

func HexToBytes(s string) []byte

func Int2Bytes

func Int2Bytes(i int64) []byte

func Int64ToBytes

func Int64ToBytes(i int64) []byte

func JoinBytes

func JoinBytes(data ...[]byte) []byte

func LeftPadBytes

func LeftPadBytes(slice []byte, l int) []byte

LeftPadBytes zero-pads slice to the left up to length l.

func Max

func Max(x, y uint64) uint64

func Min

func Min(x, y uint64) uint64

func PaddedBigBytes

func PaddedBigBytes(bigint *big.Int, n int) []byte

PaddedBigBytes encodes a big integer as a big-endian byte slice. The length of the slice is at least n bytes.

func ReadBits

func ReadBits(bigint *big.Int, buf []byte)

ReadBits encodes the absolute amount of bigint as big-endian bytes. Callers must ensure that buf has enough space. If buf is too short the result will be incomplete.

func ReverseBytes

func ReverseBytes(str []byte) (result []byte)

func RightPadBytes

func RightPadBytes(slice []byte, l int) []byte

RightPadBytes zero-pads slice to the right up to length l.

func S256

func S256(x *big.Int) *big.Int

S256 interprets x as a two's complement number. x must not exceed 256 bits (the result is undefined if it does) and is not modified.

S256(0)        = 0
S256(1)        = 1
S256(2**255)   = -2**255
S256(2**256-1) = -1

func SafeAdd

func SafeAdd(x, y uint64) (uint64, bool)

SafeAdd returns the result and whether overflow occurred.

func SafeMul

func SafeMul(x, y uint64) (uint64, bool)

SafeMul returns multiplication result and whether overflow occurred.

func SafeSub

func SafeSub(x, y uint64) (uint64, bool)

SafeSub returns subtraction result and whether overflow occurred.

func String2Bytes

func String2Bytes(s string) []byte

func StringToBigInt

func StringToBigInt(str *string) (*big.Int, error)

func ToHex

func ToHex(b []byte) string

ToHex returns the hex representation of b, prefixed with '0x'. For empty slices, the return value is "0x0".

Deprecated: use hexutil.Encode instead.

func ToIndentString

func ToIndentString(v interface{}) string

func ToString

func ToString(v interface{}) string

func ToWordSize

func ToWordSize(size uint64) uint64

ToWordSize returns the ceiled word size required for memory expansion.

func TrimBuffToString

func TrimBuffToString(bytes []byte) string

trim the '\00' byte

func TrimQuotes

func TrimQuotes(s string) string

TrimQuotes trim quotes of string if quotes exist

func U256

func U256(x *big.Int) *big.Int

U256 encodes as a 256 bit two's complement number. This operation is destructive.

func Uint64ToBytes

func Uint64ToBytes(i uint64) []byte