forked from cwtch.im/tapir
23 lines
863 B
Go
23 lines
863 B
Go
package utils
|
|
|
|
import (
|
|
"github.com/agl/ed25519/extra25519"
|
|
"golang.org/x/crypto/curve25519"
|
|
"golang.org/x/crypto/ed25519"
|
|
)
|
|
|
|
// EDH implements diffie hellman using curve25519 keys derived from ed25519 keys
|
|
// NOTE: This uses a 3rd party library extra25519 as the key conversion is not in the core golang lib
|
|
// as such this definitely needs further review.
|
|
func EDH(privateKey ed25519.PrivateKey, remotePublicKey ed25519.PublicKey) [32]byte {
|
|
var privKeyBytes [64]byte
|
|
var remotePubKeyBytes [32]byte
|
|
copy(privKeyBytes[:], privateKey[:])
|
|
copy(remotePubKeyBytes[:], remotePublicKey[:])
|
|
var secret, curve25519priv, curve25519pub [32]byte
|
|
extra25519.PrivateKeyToCurve25519(&curve25519priv, &privKeyBytes)
|
|
extra25519.PublicKeyToCurve25519(&curve25519pub, &remotePubKeyBytes)
|
|
curve25519.ScalarMult(&secret, &curve25519priv, &curve25519pub)
|
|
return secret
|
|
}
|