cmd: abstract getPassPhrase functions into one (#21219)

* [cmd] Abstract `getPassPhrase` functions into one.

* cmd/ethkey: fix compilation failure

Co-authored-by: rjl493456442 <garyrong0905@gmail.com>

cmd/utils/prompt.go

@@ -0,0 +1,62 @@
+// Copyright 2020 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package utils contains internal helper functions for go-ethereum commands.
+package utils
+
+import (
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/console/prompt"
+)
+
+// GetPassPhrase displays the given text(prompt) to the user and requests some textual
+// data to be entered, but one which must not be echoed out into the terminal.
+// The method returns the input provided by the user.
+func GetPassPhrase(text string, confirmation bool) string {
+	if text != "" {
+		fmt.Println(text)
+	}
+	password, err := prompt.Stdin.PromptPassword("Password: ")
+	if err != nil {
+		Fatalf("Failed to read password: %v", err)
+	}
+	if confirmation {
+		confirm, err := prompt.Stdin.PromptPassword("Repeat password: ")
+		if err != nil {
+			Fatalf("Failed to read password confirmation: %v", err)
+		}
+		if password != confirm {
+			Fatalf("Passwords do not match")
+		}
+	}
+	return password
+}
+
+// GetPassPhraseWithList retrieves the password associated with an account, either fetched
+// from a list of preloaded passphrases, or requested interactively from the user.
+func GetPassPhraseWithList(text string, confirmation bool, index int, passwords []string) string {
+	// If a list of passwords was supplied, retrieve from them
+	if len(passwords) > 0 {
+		if index < len(passwords) {
+			return passwords[index]
+		}
+		return passwords[len(passwords)-1]
+	}
+	// Otherwise prompt the user for the password
+	password := GetPassPhrase(text, confirmation)
+	return password
+}