Use a byte slice when generating passwords

Go 1.15 complained about the conversion from int64 to string.

Author: cbandy

internal/util/secrets.go

@@ -76,9 +76,7 @@ func CreateSecret(clientset kubernetes.Interface, db, secretName, username, pass
 // GeneratePassword generates a password of a given length out of the acceptable
 // ASCII characters suitable for a password
 func GeneratePassword(length int) (string, error) {
-	// for "length" times, we are going to get a random ASCII character, and
-	// append it to the  "password" string
-	password := ""
+	password := make([]byte, length)
 
 	for i := 0; i < length; i++ {
 		char, err := rand.Int(rand.Reader, passwordCharSelector)
@@ -88,10 +86,10 @@ func GeneratePassword(length int) (string, error) {
 			return "", err
 		}
 
-		password += string(passwordCharLower + char.Int64())
+		password[i] = byte(passwordCharLower + char.Int64())
 	}
 
-	return password, nil
+	return string(password), nil
 }
 
 // GeneratedPasswordLength returns the value for what the length of a

internal/util/secrets_test.go

@@ -0,0 +1,58 @@
+package util
+
+/*
+ Copyright 2020 Crunchy Data Solutions, Inc.
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+*/
+
+import (
+	"strings"
+	"testing"
+	"unicode"
+)
+
+func TestGeneratePassword(t *testing.T) {
+	// different lengths
+	for _, length := range []int{1, 2, 3, 5, 20} {
+		password, err := GeneratePassword(length)
+		if err != nil {
+			t.Fatalf("expected no error, got %v", err)
+		}
+		if expected, actual := length, len(password); expected != actual {
+			t.Fatalf("expected length %v, got %v", expected, actual)
+		}
+		if i := strings.IndexFunc(password, unicode.IsPrint); i > 0 {
+			t.Fatalf("expected only printable characters, got %q in %q", password[i], password)
+		}
+	}
+
+	// random contents
+	previous := []string{}
+
+	for i := 0; i < 10; i++ {
+		password, err := GeneratePassword(5)
+		if err != nil {
+			t.Fatalf("expected no error, got %v", err)
+		}
+		if i := strings.IndexFunc(password, unicode.IsPrint); i > 0 {
+			t.Fatalf("expected only printable characters, got %q in %q", password[i], password)
+		}
+
+		for i := range previous {
+			if password == previous[i] {
+				t.Fatalf("expected passwords to not repeat, got %q after %q", password, previous)
+			}
+		}
+		previous = append(previous, password)
+	}
+}