p2p/discover: remove use of shared hash instance for key derivation (#21673)

For some reason, using the shared hash causes a cryptographic incompatibility
when using Go 1.15. I noticed this during the development of Discovery v5.1
when I added test vector verification.

The go library commit that broke this is golang/go@97240d5, but the
way we used HKDF is slightly dodgy anyway and it's not a regression.
This commit is contained in:
Felix Lange 2020-10-08 11:19:54 +02:00 committed by GitHub
parent 6d29e192e9
commit 5e86e4ed29
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23

View File

@ -383,7 +383,7 @@ func (c *wireCodec) deriveKeys(n1, n2 enode.ID, priv *ecdsa.PrivateKey, pub *ecd
info := []byte("discovery v5 key agreement")
info = append(info, n1[:]...)
info = append(info, n2[:]...)
kdf := hkdf.New(c.sha256reset, eph, challenge.IDNonce[:], info)
kdf := hkdf.New(sha256.New, eph, challenge.IDNonce[:], info)
sec := handshakeSecrets{
writeKey: make([]byte, aesKeySize),
readKey: make([]byte, aesKeySize),