crypto

Documentation

Overview

Package crypto contains several cryptography modules used in Kaia.

crypto package provides various cryptographic functions such as key generation, ECDSA conversion, signature verification and so on.

Source Files

Each source file contains the following contents.

• crypto.go : Provides functions for private key generation and conversion, Keccak hash functions and address generation
• signature_cgo.go : Provides public key and signature related functions. These functions depend on secp256k1 package which utilizes C library libsecp256k1

Index

• Constants
• func CompressPubkey(pubkey *ecdsa.PublicKey) []byte
• func CreateAddress(b common.Address, nonce uint64) common.Address
• func CreateAddress2(b common.Address, salt [32]byte, inithash []byte) common.Address
• func DecompressPubkey(pubkey []byte) (*ecdsa.PublicKey, error)
• func Ecrecover(hash, sig []byte) ([]byte, error)
• func FromECDSA(priv *ecdsa.PrivateKey) []byte
• func FromECDSAPub(pub *ecdsa.PublicKey) []byte
• func GenerateKey() (*ecdsa.PrivateKey, error)
• func HexToECDSA(hexkey string) (*ecdsa.PrivateKey, error)
• func Keccak256(data ...[]byte) []byte
• func Keccak256Hash(data ...[]byte) (h common.Hash)
• func Keccak512(data ...[]byte) []byte
• func LoadECDSA(file string) (*ecdsa.PrivateKey, error)
• func PubkeyToAddress(p ecdsa.PublicKey) common.Address
• func SaveECDSA(file string, key *ecdsa.PrivateKey) error
• func SigToPub(hash, sig []byte) (*ecdsa.PublicKey, error)
• func Sign(digestHash []byte, prv *ecdsa.PrivateKey) (sig []byte, err error)
• func ToECDSA(d []byte) (*ecdsa.PrivateKey, error)
• func ToECDSAUnsafe(d []byte) *ecdsa.PrivateKey
• func UnmarshalPubkey(pub []byte) (*ecdsa.PublicKey, error)
• func ValidateSignatureValues(v byte, r, s *big.Int, homestead bool) bool
• func VerifySignature(pubkey, digestHash, signature []byte) bool
• type EllipticCurve
  • func S256() EllipticCurve

Constants

const DigestLength = 32

DigestLength sets the signature digest exact length

const RecoveryIDOffset = 64

RecoveryIDOffset points to the byte offset within the signature that contains the recovery id.

const SignatureLength = 64 + 1 // 64 bytes ECDSA signature + 1 byte recovery id

SignatureLength indicates the byte length required to carry a signature with recovery id.

Functions

func CompressPubkey

func CompressPubkey(pubkey *ecdsa.PublicKey) []byte

CompressPubkey encodes a public key to the 33-byte compressed format.

func CreateAddress

func CreateAddress(b common.Address, nonce uint64) common.Address

CreateAddress creates a Kaia address given the bytes and the nonce

func CreateAddress2

func CreateAddress2(b common.Address, salt [32]byte, inithash []byte) common.Address

CreateAddress2 creates a Kaia address given the address bytes, initial contract code hash and a salt.

func DecompressPubkey

func DecompressPubkey(pubkey []byte) (*ecdsa.PublicKey, error)

DecompressPubkey parses a public key in the 33-byte compressed format.

func Ecrecover

func Ecrecover(hash, sig []byte) ([]byte, error)

Ecrecover returns the uncompressed public key that created the given signature.

func FromECDSA

func FromECDSA(priv *ecdsa.PrivateKey) []byte

FromECDSA exports a private key into a binary dump.

func FromECDSAPub

func FromECDSAPub(pub *ecdsa.PublicKey) []byte

func GenerateKey

func GenerateKey() (*ecdsa.PrivateKey, error)

func HexToECDSA

func HexToECDSA(hexkey string) (*ecdsa.PrivateKey, error)

HexToECDSA parses a secp256k1 private key.

func Keccak256

func Keccak256(data ...[]byte) []byte

Keccak256 calculates and returns the Keccak256 hash of the input data.

func Keccak256Hash

func Keccak256Hash(data ...[]byte) (h common.Hash)

Keccak256Hash calculates and returns the Keccak256 hash of the input data, converting it to an internal Hash data structure.

func Keccak512

func Keccak512(data ...[]byte) []byte

Keccak512 calculates and returns the Keccak512 hash of the input data.

func LoadECDSA

func LoadECDSA(file string) (*ecdsa.PrivateKey, error)

LoadECDSA loads a secp256k1 private key from the given file.

func PubkeyToAddress

func PubkeyToAddress(p ecdsa.PublicKey) common.Address

func SaveECDSA

func SaveECDSA(file string, key *ecdsa.PrivateKey) error

SaveECDSA saves a secp256k1 private key to the given file with restrictive permissions. The key data is saved hex-encoded.

func SigToPub

func SigToPub(hash, sig []byte) (*ecdsa.PublicKey, error)

SigToPub returns the public key that created the given signature.

func Sign

func Sign(digestHash []byte, prv *ecdsa.PrivateKey) (sig []byte, err error)

Sign calculates an ECDSA signature.

This function is susceptible to chosen plaintext attacks that can leak information about the private key that is used for signing. Callers must be aware that the given digest cannot be chosen by an adversery. Common solution is to hash any input before calculating the signature.

The produced signature is in the [R || S || V] format where V is 0 or 1.

func ToECDSA

func ToECDSA(d []byte) (*ecdsa.PrivateKey, error)

ToECDSA creates a private key with the given D value.

func ToECDSAUnsafe

func ToECDSAUnsafe(d []byte) *ecdsa.PrivateKey

ToECDSAUnsafe blindly converts a binary blob to a private key. It should almost never be used unless you are sure the input is valid and want to avoid hitting errors due to bad origin encoding (0 prefixes cut off).

func UnmarshalPubkey

func UnmarshalPubkey(pub []byte) (*ecdsa.PublicKey, error)

UnmarshalPubkey converts bytes to a secp256k1 public key.

func ValidateSignatureValues

func ValidateSignatureValues(v byte, r, s *big.Int, homestead bool) bool

ValidateSignatureValues verifies whether the signature values are valid with the given chain rules. The v value is assumed to be either 0 or 1.

func VerifySignature

func VerifySignature(pubkey, digestHash, signature []byte) bool

VerifySignature checks that the given public key created signature over digest. The public key should be in compressed (33 bytes) or uncompressed (65 bytes) format. The signature should have the 64 byte [R || S] format.

Types

type EllipticCurve

type EllipticCurve interface {
	elliptic.Curve

	// Point marshaling/unmarshaing.
	Marshal(x, y *big.Int) []byte
	Unmarshal(data []byte) (x, y *big.Int)
}

EllipticCurve contains curve operations.

func S256

func S256() EllipticCurve

S256 returns an instance of the secp256k1 curve.