cmd/geth: make geth account new faster with many keys (#15529)

accounts/keystore/keystore_passphrase.go

@@ -28,6 +28,7 @@ package keystore
 import (
 	"bytes"
 	"crypto/aes"
+	crand "crypto/rand"
 	"crypto/sha256"
 	"encoding/hex"
 	"encoding/json"
@@ -90,6 +91,12 @@ func (ks keyStorePassphrase) GetKey(addr common.Address, filename, auth string)
 	return key, nil
 }
 
+// StoreKey generates a key, encrypts with 'auth' and stores in the given directory
+func StoreKey(dir, auth string, scryptN, scryptP int) (common.Address, error) {
+	_, a, err := storeNewKey(&keyStorePassphrase{dir, scryptN, scryptP}, crand.Reader, auth)
+	return a.Address, err
+}
+
 func (ks keyStorePassphrase) StoreKey(filename string, key *Key, auth string) error {
 	keyjson, err := EncryptKey(key, auth, ks.scryptN, ks.scryptP)
 	if err != nil {