73 lines
1.3 KiB
Go
73 lines
1.3 KiB
Go
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package ecdh
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import (
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"crypto/ecdh"
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"crypto/rand"
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"errors"
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)
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var Curve = ecdh.P521()
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var ERROR_SharedNotComputed = errors.New("Shared secret is not computed!")
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type ECDHConnection struct {
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privateKey *ecdh.PrivateKey
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otherPublicKey *ecdh.PublicKey
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sharedSecret []byte
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}
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func CreateNewConnection() (*ECDHConnection, error) {
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privKey, err := generatePrivKey()
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if err != nil {
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return nil, err
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}
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return &ECDHConnection{
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privateKey: privKey,
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}, nil
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}
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func (c *ECDHConnection) GetMyPublicKeyBytes() []byte {
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return c.privateKey.PublicKey().Bytes()
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}
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func (c *ECDHConnection) AcceptOtherPubKeyBytes(pubBytes []byte) error {
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pubKey, err := Curve.NewPublicKey(pubBytes)
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if err != nil {
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return err
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}
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c.otherPublicKey = pubKey
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shared, err := c.privateKey.ECDH(pubKey)
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if err != nil {
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return err
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}
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c.sharedSecret = shared
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return nil
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}
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func (c *ECDHConnection) GetShared() ([]byte, error) {
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if len(c.sharedSecret) == 0 {
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return nil, ERROR_SharedNotComputed
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}
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return c.sharedSecret, nil
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}
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func generatePrivKey() (*ecdh.PrivateKey, error) {
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privateKey, err := Curve.GenerateKey(rand.Reader)
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if err != nil {
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return nil, err
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}
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return privateKey, err
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}
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func AreKeysEqual(a, b []byte) bool {
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if len(a) != len(b) {
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return false
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}
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for i := range a {
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if a[i] != b[i] {
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return false
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}
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}
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return true
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}
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