crypto

README

crypto

crypto is the cryptographic package adapted for Tendermint's uses

Importing it

To get the interfaces, import "github.com/tendermint/tendermint/crypto"

For any specific algorithm, use its specific module e.g. import "github.com/tendermint/tendermint/crypto/ed25519"

If you want to decode bytes into one of the types, but don't care about the specific algorithm, use import "github.com/tendermint/tendermint/crypto/amino"

Binary encoding

For Binary encoding, please refer to the Tendermint encoding spec.

JSON Encoding

crypto .Bytes() uses Amino:binary encoding, but Amino:JSON is also supported.

Example Amino:JSON encodings:

ed25519.PrivKeyEd25519     - {"type":"954568A3288910","value":"EVkqJO/jIXp3rkASXfh9YnyToYXRXhBr6g9cQVxPFnQBP/5povV4HTjvsy530kybxKHwEi85iU8YL0qQhSYVoQ=="}
ed25519.PubKeyEd25519      - {"type":"AC26791624DE60","value":"AT/+aaL1eB0477Mud9JMm8Sh8BIvOYlPGC9KkIUmFaE="}
crypto.PrivKeySecp256k1   - {"type":"019E82E1B0F798","value":"zx4Pnh67N+g2V+5vZbQzEyRerX9c4ccNZOVzM9RvJ0Y="}
crypto.PubKeySecp256k1    - {"type":"F8CCEAEB5AE980","value":"A8lPKJXcNl5VHt1FK8a244K9EJuS4WX1hFBnwisi0IJx"}

Documentation

Overview

Ripemd160

sum := crypto.Ripemd160([]byte("This is consensus"))
fmt.Printf("%x\n", sum)

Index

• Constants
• func CRandBytes(numBytes int) []byte
• func CRandHex(numDigits int) string
• func CReader() io.Reader
• func MixEntropy(seedBytes []byte)
• func Ripemd160(bytes []byte) []byte
• func Sha256(bytes []byte) []byte
• type Address
  • func AddressHash(bz []byte) Address
• type PrivKey
• type PubKey
• type Symmetric

Examples

• Ripemd160
• Sha256

Constants

const (
	// AddressSize is the size of a pubkey address.
	AddressSize = tmhash.TruncatedSize
)

const Version = "0.9.0-dev"

Functions

func CRandBytes

func CRandBytes(numBytes int) []byte

This only uses the OS's randomness

func CRandHex

func CRandHex(numDigits int) string

CRandHex returns a hex encoded string that's floor(numDigits/2) * 2 long.

Note: CRandHex(24) gives 96 bits of randomness that are usually strong enough for most purposes.

func CReader

func CReader() io.Reader

Returns a crand.Reader.

func MixEntropy

func MixEntropy(seedBytes []byte)

WARNING: This function needs review - https://github.com/tendermint/tendermint/issues/2099. Mix additional bytes of randomness, e.g. from hardware, user-input, etc. It is OK to call it multiple times. It does not diminish security.

func Ripemd160

func Ripemd160(bytes []byte) []byte

Example

package main

import (
	"fmt"

	"github.com/tendermint/tendermint/crypto"
)

func main() {
	sum := crypto.Ripemd160([]byte("This is Tendermint"))
	fmt.Printf("%x\n", sum)
}

Output:

051e22663e8f0fd2f2302f1210f954adff009005

func Sha256

func Sha256(bytes []byte) []byte

Example

package main

import (
	"fmt"

	"github.com/tendermint/tendermint/crypto"
)

func main() {
	sum := crypto.Sha256([]byte("This is Tendermint"))
	fmt.Printf("%x\n", sum)
}

Output:

f91afb642f3d1c87c17eb01aae5cb65c242dfdbe7cf1066cc260f4ce5d33b94e

Types

type Address

type Address = cmn.HexBytes

An address is a []byte, but hex-encoded even in JSON. []byte leaves us the option to change the address length. Use an alias so Unmarshal methods (with ptr receivers) are available too.

func AddressHash

func AddressHash(bz []byte) Address

type PrivKey

type PrivKey interface {
	Bytes() []byte
	Sign(msg []byte) ([]byte, error)
	PubKey() PubKey
	Equals(PrivKey) bool
}

type PubKey

type PubKey interface {
	Address() Address
	Bytes() []byte
	VerifyBytes(msg []byte, sig []byte) bool
	Equals(PubKey) bool
}

type Symmetric

type Symmetric interface {
	Keygen() []byte
	Encrypt(plaintext []byte, secret []byte) (ciphertext []byte)
	Decrypt(ciphertext []byte, secret []byte) (plaintext []byte, err error)
}