tendermint/p2p/key.go
ValarDragon 99e582d79a crypto: Refactor to move files out of the top level directory
Currently the top level directory contains basically all of the code
for the crypto package. This PR moves the crypto code into submodules
in a similar manner to what `golang/x/crypto` does. This improves code
organization.

Ref discussion: https://github.com/tendermint/tendermint/pull/1966

Closes #1956
2018-07-18 08:38:44 -07:00

113 lines
3.1 KiB
Go

package p2p
import (
"bytes"
"encoding/hex"
"fmt"
"io/ioutil"
crypto "github.com/tendermint/tendermint/crypto"
"github.com/tendermint/tendermint/crypto/ed25519"
cmn "github.com/tendermint/tendermint/libs/common"
)
// ID is a hex-encoded crypto.Address
type ID string
// IDByteLength is the length of a crypto.Address. Currently only 20.
// TODO: support other length addresses ?
const IDByteLength = 20
//------------------------------------------------------------------------------
// Persistent peer ID
// TODO: encrypt on disk
// NodeKey is the persistent peer key.
// It contains the nodes private key for authentication.
type NodeKey struct {
PrivKey crypto.PrivKey `json:"priv_key"` // our priv key
}
// ID returns the peer's canonical ID - the hash of its public key.
func (nodeKey *NodeKey) ID() ID {
return PubKeyToID(nodeKey.PubKey())
}
// PubKey returns the peer's PubKey
func (nodeKey *NodeKey) PubKey() crypto.PubKey {
return nodeKey.PrivKey.PubKey()
}
// PubKeyToID returns the ID corresponding to the given PubKey.
// It's the hex-encoding of the pubKey.Address().
func PubKeyToID(pubKey crypto.PubKey) ID {
return ID(hex.EncodeToString(pubKey.Address()))
}
// LoadOrGenNodeKey attempts to load the NodeKey from the given filePath.
// If the file does not exist, it generates and saves a new NodeKey.
func LoadOrGenNodeKey(filePath string) (*NodeKey, error) {
if cmn.FileExists(filePath) {
nodeKey, err := LoadNodeKey(filePath)
if err != nil {
return nil, err
}
return nodeKey, nil
}
return genNodeKey(filePath)
}
func LoadNodeKey(filePath string) (*NodeKey, error) {
jsonBytes, err := ioutil.ReadFile(filePath)
if err != nil {
return nil, err
}
nodeKey := new(NodeKey)
err = cdc.UnmarshalJSON(jsonBytes, nodeKey)
if err != nil {
return nil, fmt.Errorf("Error reading NodeKey from %v: %v", filePath, err)
}
return nodeKey, nil
}
func genNodeKey(filePath string) (*NodeKey, error) {
privKey := ed25519.GenPrivKeyEd25519()
nodeKey := &NodeKey{
PrivKey: privKey,
}
jsonBytes, err := cdc.MarshalJSON(nodeKey)
if err != nil {
return nil, err
}
err = ioutil.WriteFile(filePath, jsonBytes, 0600)
if err != nil {
return nil, err
}
return nodeKey, nil
}
//------------------------------------------------------------------------------
// MakePoWTarget returns the big-endian encoding of 2^(targetBits - difficulty) - 1.
// It can be used as a Proof of Work target.
// NOTE: targetBits must be a multiple of 8 and difficulty must be less than targetBits.
func MakePoWTarget(difficulty, targetBits uint) []byte {
if targetBits%8 != 0 {
panic(fmt.Sprintf("targetBits (%d) not a multiple of 8", targetBits))
}
if difficulty >= targetBits {
panic(fmt.Sprintf("difficulty (%d) >= targetBits (%d)", difficulty, targetBits))
}
targetBytes := targetBits / 8
zeroPrefixLen := (int(difficulty) / 8)
prefix := bytes.Repeat([]byte{0}, zeroPrefixLen)
mod := (difficulty % 8)
if mod > 0 {
nonZeroPrefix := byte(1<<(8-mod) - 1)
prefix = append(prefix, nonZeroPrefix)
}
tailLen := int(targetBytes) - len(prefix)
return append(prefix, bytes.Repeat([]byte{0xFF}, tailLen)...)
}