path: root/common/types.go

// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package common

import (
    "database/sql/driver"
    "encoding/hex"
    "encoding/json"
    "fmt"
    "math/big"
    "math/rand"
    "reflect"
    "strings"

    "github.com/tangerine-network/go-tangerine/common/hexutil"
    "golang.org/x/crypto/sha3"
)

// Lengths of hashes and addresses in bytes.
const (
    // HashLength is the expected length of the hash
    HashLength = 32
    // AddressLength is the expected length of the address
    AddressLength = 20
)

var (
    hashT    = reflect.TypeOf(Hash{})
    addressT = reflect.TypeOf(Address{})
)

// Hash represents the 32 byte Keccak256 hash of arbitrary data.
type Hash [HashLength]byte

// BytesToHash sets b to hash.
// If b is larger than len(h), b will be cropped from the left.
func BytesToHash(b []byte) Hash {
    var h Hash
    h.SetBytes(b)
    return h
}

// BigToHash sets byte representation of b to hash.
// If b is larger than len(h), b will be cropped from the left.
func BigToHash(b *big.Int) Hash { return BytesToHash(b.Bytes()) }

// HexToHash sets byte representation of s to hash.
// If b is larger than len(h), b will be cropped from the left.
func HexToHash(s string) Hash { return BytesToHash(FromHex(s)) }

// Bytes gets the byte representation of the underlying hash.
func (h Hash) Bytes() []byte { return h[:] }

// Big converts a hash to a big integer.
func (h Hash) Big() *big.Int { return new(big.Int).SetBytes(h[:]) }

// Hex converts a hash to a hex string.
func (h Hash) Hex() string { return hexutil.Encode(h[:]) }

// TerminalString implements log.TerminalStringer, formatting a string for console
// output during logging.
func (h Hash) TerminalString() string {
    return fmt.Sprintf("%x…%x", h[:3], h[29:])
}

// String implements the stringer interface and is used also by the logger when
// doing full logging into a file.
func (h Hash) String() string {
    return h.Hex()
}

// Format implements fmt.Formatter, forcing the byte slice to be formatted as is,
// without going through the stringer interface used for logging.
func (h Hash) Format(s fmt.State, c rune) {
    fmt.Fprintf(s, "%"+string(c), h[:])
}

// UnmarshalText parses a hash in hex syntax.
func (h *Hash) UnmarshalText(input []byte) error {
    return hexutil.UnmarshalFixedText("Hash", input, h[:])
}

// UnmarshalJSON parses a hash in hex syntax.
func (h *Hash) UnmarshalJSON(input []byte) error {
    return hexutil.UnmarshalFixedJSON(hashT, input, h[:])
}

// MarshalText returns the hex representation of h.
func (h Hash) MarshalText() ([]byte, error) {
    return hexutil.Bytes(h[:]).MarshalText()
}

// SetBytes sets the hash to the value of b.
// If b is larger than len(h), b will be cropped from the left.
func (h *Hash) SetBytes(b []byte) {
    if len(b) > len(h) {
        b = b[len(b)-HashLength:]
    }

    copy(h[HashLength-len(b):], b)
}

// Generate implements testing/quick.Generator.
func (h Hash) Generate(rand *rand.Rand, size int) reflect.Value {
    m := rand.Intn(len(h))
    for i := len(h) - 1; i > m; i-- {
        h[i] = byte(rand.Uint32())
    }
    return reflect.ValueOf(h)
}

// Scan implements Scanner for database/sql.
func (h *Hash) Scan(src interface{}) error {
    srcB, ok := src.([]byte)
    if !ok {
        return fmt.Errorf("can't scan %T into Hash", src)
    }
    if len(srcB) != HashLength {
        return fmt.Errorf("can't scan []byte of len %d into Hash, want %d", len(srcB), HashLength)
    }
    copy(h[:], srcB)
    return nil
}

// Value implements valuer for database/sql.
func (h Hash) Value() (driver.Value, error) {
    return h[:], nil
}

// UnprefixedHash allows marshaling a Hash without 0x prefix.
type UnprefixedHash Hash

// UnmarshalText decodes the hash from hex. The 0x prefix is optional.
func (h *UnprefixedHash) UnmarshalText(input []byte) error {
    return hexutil.UnmarshalFixedUnprefixedText("UnprefixedHash", input, h[:])
}

// MarshalText encodes the hash as hex.
func (h UnprefixedHash) MarshalText() ([]byte, error) {
    return []byte(hex.EncodeToString(h[:])), nil
}

/////////// Address

// Address represents the 20 byte address of an Ethereum account.
type Address [AddressLength]byte

// BytesToAddress returns Address with value b.
// If b is larger than len(h), b will be cropped from the left.
func BytesToAddress(b []byte) Address {
    var a Address
    a.SetBytes(b)
    return a
}

// BigToAddress returns Address with byte values of b.
// If b is larger than len(h), b will be cropped from the left.
func BigToAddress(b *big.Int) Address { return BytesToAddress(b.Bytes()) }

// HexToAddress returns Address with byte values of s.
// If s is larger than len(h), s will be cropped from the left.
func HexToAddress(s string) Address { return BytesToAddress(FromHex(s)) }

// IsHexAddress verifies whether a string can represent a valid hex-encoded
// Ethereum address or not.
func IsHexAddress(s string) bool {
    if hasHexPrefix(s) {
        s = s[2:]
    }
    return len(s) == 2*AddressLength && isHex(s)
}

// Bytes gets the string representation of the underlying address.
func (a Address) Bytes() []byte { return a[:] }

// Big converts an address to a big integer.
func (a Address) Big() *big.Int { return new(big.Int).SetBytes(a[:]) }

// Hash converts an address to a hash by left-padding it with zeros.
func (a Address) Hash() Hash { return BytesToHash(a[:]) }

// Hex returns an EIP55-compliant hex string representation of the address.
func (a Address) Hex() string {
    unchecksummed := hex.EncodeToString(a[:])
    sha := sha3.NewLegacyKeccak256()
    sha.Write([]byte(unchecksummed))
    hash := sha.Sum(nil)

    result := []byte(unchecksummed)
    for i := 0; i < len(result); i++ {
        hashByte := hash[i/2]
        if i%2 == 0 {
            hashByte = hashByte >> 4
        } else {
            hashByte &= 0xf
        }
        if result[i] > '9' && hashByte > 7 {
            result[i] -= 32
        }
    }
    return "0x" + string(result)
}

// String implements fmt.Stringer.
func (a Address) String() string {
    return a.Hex()
}

// Format implements fmt.Formatter, forcing the byte slice to be formatted as is,
// without going through the stringer interface used for logging.
func (a Address) Format(s fmt.State, c rune) {
    fmt.Fprintf(s, "%"+string(c), a[:])
}

// SetBytes sets the address to the value of b.
// If b is larger than len(a) it will panic.
func (a *Address) SetBytes(b []byte) {
    if len(b) > len(a) {
        b = b[len(b)-AddressLength:]
    }
    copy(a[AddressLength-len(b):], b)
}

// MarshalText returns the hex representation of a.
func (a Address) MarshalText() ([]byte, error) {
    return hexutil.Bytes(a[:]).MarshalText()
}

// UnmarshalText parses a hash in hex syntax.
func (a *Address) UnmarshalText(input []byte) error {
    return hexutil.UnmarshalFixedText("Address", input, a[:])
}

// UnmarshalJSON parses a hash in hex syntax.
func (a *Address) UnmarshalJSON(input []byte) error {
    return hexutil.UnmarshalFixedJSON(addressT, input, a[:])
}

// Scan implements Scanner for database/sql.
func (a *Address) Scan(src interface{}) error {
    srcB, ok := src.([]byte)
    if !ok {
        return fmt.Errorf("can't scan %T into Address", src)
    }
    if len(srcB) != AddressLength {
        return fmt.Errorf("can't scan []byte of len %d into Address, want %d", len(srcB), AddressLength)
    }
    copy(a[:], srcB)
    return nil
}

// Value implements valuer for database/sql.
func (a Address) Value() (driver.Value, error) {
    return a[:], nil
}

// UnprefixedAddress allows marshaling an Address without 0x prefix.
type UnprefixedAddress Address

// UnmarshalText decodes the address from hex. The 0x prefix is optional.
func (a *UnprefixedAddress) UnmarshalText(input []byte) error {
    return hexutil.UnmarshalFixedUnprefixedText("UnprefixedAddress", input, a[:])
}

// MarshalText encodes the address as hex.
func (a UnprefixedAddress) MarshalText() ([]byte, error) {
    return []byte(hex.EncodeToString(a[:])), nil
}

// MixedcaseAddress retains the original string, which may or may not be
// correctly checksummed
type MixedcaseAddress struct {
    addr     Address
    original string
}

// NewMixedcaseAddress constructor (mainly for testing)
func NewMixedcaseAddress(addr Address) MixedcaseAddress {
    return MixedcaseAddress{addr: addr, original: addr.Hex()}
}

// NewMixedcaseAddressFromString is mainly meant for unit-testing
func NewMixedcaseAddressFromString(hexaddr string) (*MixedcaseAddress, error) {
    if !IsHexAddress(hexaddr) {
        return nil, fmt.Errorf("Invalid address")
    }
    a := FromHex(hexaddr)
    return &MixedcaseAddress{addr: BytesToAddress(a), original: hexaddr}, nil
}

// UnmarshalJSON parses MixedcaseAddress
func (ma *MixedcaseAddress) UnmarshalJSON(input []byte) error {
    if err := hexutil.UnmarshalFixedJSON(addressT, input, ma.addr[:]); err != nil {
        return err
    }
    return json.Unmarshal(input, &ma.original)
}

// MarshalJSON marshals the original value
func (ma *MixedcaseAddress) MarshalJSON() ([]byte, error) {
    if strings.HasPrefix(ma.original, "0x") || strings.HasPrefix(ma.original, "0X") {
        return json.Marshal(fmt.Sprintf("0x%s", ma.original[2:]))
    }
    return json.Marshal(fmt.Sprintf("0x%s", ma.original))
}

// Address returns the address
func (ma *MixedcaseAddress) Address() Address {
    return ma.addr
}

// String implements fmt.Stringer
func (ma *MixedcaseAddress) String() string {
    if ma.ValidChecksum() {
        return fmt.Sprintf("%s [chksum ok]", ma.original)
    }
    return fmt.Sprintf("%s [chksum INVALID]", ma.original)
}

// ValidChecksum returns true if the address has valid checksum
func (ma *MixedcaseAddress) ValidChecksum() bool {
    return ma.original == ma.addr.Hex()
}

// Original returns the mixed-case input string
func (ma *MixedcaseAddress) Original() string {
    return ma.original
}