✨ Offer password generation and query

cmd_tools.go

@@ -0,0 +1,66 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"math/rand"
+
+	pwgen "github.com/sethvargo/go-password/password"
+	"golang.org/x/crypto/bcrypt"
+	"golang.org/x/crypto/ssh/terminal"
+)
+
+type PasswordParam struct {
+	Password               string `name:"password" help:"The password to be set. Empty to prompt."`
+	GeneratePassword       bool   `name:"generate-password" help:"If set, the password is auto generated."`
+	GeneratePasswordLength int    `name:"password-length" help:"If generate-password is set, this specified the length of the generated password." default:"32"`
+}
+
+func (p *PasswordParam) acquirePassword() (string, error) {
+	if p.GeneratePassword {
+		// math.rand is not secure. For determining the number of digits in a password
+		// it should suffice, though. Beware that we expect here that we at least initialized
+		// the seed somewhere.
+		pw, err := pwgen.Generate(p.GeneratePasswordLength, rand.Intn(p.GeneratePasswordLength/2), 0, false, true)
+		if err != nil {
+			return "", fmt.Errorf("cannot generate password: %w", err)
+		}
+
+		p.Password = pw
+
+		fmt.Printf("Password generated: %s\n", p.Password)
+	}
+
+	if p.Password == "" {
+		fmt.Printf("Enter password: ")
+		bytePassword, err := terminal.ReadPassword(0)
+		if err != nil {
+			fmt.Println()
+			return "", fmt.Errorf("error reading password: %w", err)
+		}
+		fmt.Printf("\nRepeat password: ")
+		bytePasswordRepeat, err := terminal.ReadPassword(0)
+		if err != nil {
+			fmt.Println()
+			return "", fmt.Errorf("error reading password: %w", err)
+		}
+		fmt.Println()
+
+		if !bytes.Equal(bytePassword, bytePasswordRepeat) {
+			return "", fmt.Errorf("passwords do not match")
+		}
+
+		p.Password = string(bytePassword)
+	}
+
+	if p.Password == "" {
+		return "", fmt.Errorf("empty password supplied")
+	}
+
+	hash, err := bcrypt.GenerateFromPassword([]byte(p.Password), 0)
+	if err != nil {
+		return "", fmt.Errorf("cannot hash password: %w", err)
+	}
+
+	return string(hash), nil
+}