refactor-for-testability (#3)

Co-authored-by: jdl <jdl@desktop>
Co-authored-by: jdl <jdl@crumpington.com>
Reviewed-on: #3

peer/crypto.go

@@ -0,0 +1,30 @@
+package peer
+
+import (
+	"crypto/rand"
+	"log"
+
+	"golang.org/x/crypto/nacl/box"
+	"golang.org/x/crypto/nacl/sign"
+)
+
+type cryptoKeys struct {
+	PubKey      []byte
+	PrivKey     []byte
+	PubSignKey  []byte
+	PrivSignKey []byte
+}
+
+func generateKeys() cryptoKeys {
+	pubKey, privKey, err := box.GenerateKey(rand.Reader)
+	if err != nil {
+		log.Fatalf("Failed to generate encryption keys: %v", err)
+	}
+
+	pubSignKey, privSignKey, err := sign.GenerateKey(rand.Reader)
+	if err != nil {
+		log.Fatalf("Failed to generate signing keys: %v", err)
+	}
+
+	return cryptoKeys{pubKey[:], privKey[:], pubSignKey[:], privSignKey[:]}
+}