From 9277e83fd49590757c63b52469ecbdb5d9253687 Mon Sep 17 00:00:00 2001
From: Winni Neessen <wn@neessen.net>
Date: Sat, 17 Apr 2021 11:04:14 +0200
Subject: [PATCH] v0.3.1: New password length behaviour

To address issue #13, the password length behaviour of the
original APG has been reproduced. Previously, when a minLength
of 5 and a maxLength of 10 was given, apg-go se the pwLength to
the preferred maxLength.

With v0.3.1 it will choose a random length between minLength and
maxLength instead, same as the original C-lang apg did. For this
the minLength has been defaulted to a sane value of 12 (instead
of the 8 of the original apg). The default for maxLength stayed
at 20.

Also the default number of generated passwords has been changed
from 1 to 6, to replicate the behaviour of the original apg.
---
 .idea/workspace.xml | 52 +++++++++++++++++++++++----------------------
 README.md           |  4 ++--
 apg_test.go         | 42 +++++++++++++++++++++++++++++++++++-
 config.go           | 19 +++++++++--------
 go.mod              |  2 +-
 5 files changed, 81 insertions(+), 38 deletions(-)

diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index 42cea83..88b69dd 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -6,8 +6,11 @@
   <component name="ChangeListManager">
     <list default="true" id="fbb0c733-4aa1-4d27-87d5-c7276d8aa613" name="Default Changelist" comment="">
       <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/README.md" beforeDir="false" afterPath="$PROJECT_DIR$/README.md" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/buildfiles/arch-linux/PKGBUILD" beforeDir="false" afterPath="$PROJECT_DIR$/buildfiles/arch-linux/PKGBUILD" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/apg.go" beforeDir="false" afterPath="$PROJECT_DIR$/apg.go" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/apg_test.go" beforeDir="false" afterPath="$PROJECT_DIR$/apg_test.go" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/config.go" beforeDir="false" afterPath="$PROJECT_DIR$/config.go" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/go.mod" beforeDir="false" afterPath="$PROJECT_DIR$/go.mod" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/rand.go" beforeDir="false" afterPath="$PROJECT_DIR$/rand.go" afterDir="false" />
     </list>
     <option name="SHOW_DIALOG" value="false" />
     <option name="HIGHLIGHT_CONFLICTS" value="true" />
@@ -49,7 +52,6 @@
   <component name="ProjectViewState">
     <option name="hideEmptyMiddlePackages" value="true" />
     <option name="showLibraryContents" value="true" />
-    <option name="showMembers" value="true" />
   </component>
   <component name="PropertiesComponent">
     <property name="DefaultGoTemplateProperty" value="Go Application" />
@@ -71,15 +73,15 @@
       <recent name="C:\Users\Winni Neessen\go\src\apg.go\test" />
     </key>
   </component>
-  <component name="RunManager" selected="Go Test.Test Application">
+  <component name="RunManager" selected="Go Build.Run Application (with newstyle params)">
     <configuration name="Run Application (show help text)" type="GoApplicationRunConfiguration" factoryName="Go Application">
       <module name="apg.go" />
       <working_directory value="$PROJECT_DIR$" />
       <parameters value="-h" />
       <kind value="PACKAGE" />
-      <filePath value="$PROJECT_DIR$" />
-      <package value="github.com/wneessen/apg.go" />
+      <package value="github.com/wneessen/apg-go" />
       <directory value="$PROJECT_DIR$" />
+      <filePath value="$PROJECT_DIR$" />
       <method v="2" />
     </configuration>
     <configuration name="Run Application (show version string)" type="GoApplicationRunConfiguration" factoryName="Go Application">
@@ -87,9 +89,9 @@
       <working_directory value="$PROJECT_DIR$" />
       <parameters value="-v" />
       <kind value="PACKAGE" />
-      <filePath value="$PROJECT_DIR$" />
-      <package value="github.com/wneessen/apg.go" />
+      <package value="github.com/wneessen/apg-go" />
       <directory value="$PROJECT_DIR$" />
+      <filePath value="$PROJECT_DIR$" />
       <method v="2" />
     </configuration>
     <configuration name="Run Application (with excludes)" type="GoApplicationRunConfiguration" factoryName="Go Application">
@@ -97,9 +99,9 @@
       <working_directory value="$PROJECT_DIR$" />
       <parameters value="-m 20 -x 20 -C -E abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890!]" />
       <kind value="PACKAGE" />
-      <filePath value="$PROJECT_DIR$" />
-      <package value="github.com/wneessen/apg.go" />
+      <package value="github.com/wneessen/apg-go" />
       <directory value="$PROJECT_DIR$" />
+      <filePath value="$PROJECT_DIR$" />
       <method v="2" />
     </configuration>
     <configuration name="Run Application (with newstyle params and spelling and multiple pws)" type="GoApplicationRunConfiguration" factoryName="Go Application">
@@ -107,9 +109,9 @@
       <working_directory value="$PROJECT_DIR$" />
       <parameters value="-m 10 -x 10 -M SLNU -l -n 6" />
       <kind value="PACKAGE" />
-      <filePath value="$PROJECT_DIR$" />
-      <package value="github.com/wneessen/apg.go" />
+      <package value="github.com/wneessen/apg-go" />
       <directory value="$PROJECT_DIR$" />
+      <filePath value="$PROJECT_DIR$" />
       <method v="2" />
     </configuration>
     <configuration name="Run Application (with newstyle params and spelling)" type="GoApplicationRunConfiguration" factoryName="Go Application">
@@ -117,19 +119,19 @@
       <working_directory value="$PROJECT_DIR$" />
       <parameters value="-m 10 -x 10 -M SLNU -l" />
       <kind value="PACKAGE" />
-      <filePath value="$PROJECT_DIR$" />
-      <package value="github.com/wneessen/apg.go" />
+      <package value="github.com/wneessen/apg-go" />
       <directory value="$PROJECT_DIR$" />
+      <filePath value="$PROJECT_DIR$" />
       <method v="2" />
     </configuration>
     <configuration name="Run Application (with newstyle params)" type="GoApplicationRunConfiguration" factoryName="Go Application">
       <module name="apg.go" />
       <working_directory value="$PROJECT_DIR$" />
-      <parameters value="-m 20 -x 20 -M slNU" />
+      <parameters value="-M slNU" />
       <kind value="PACKAGE" />
-      <filePath value="$PROJECT_DIR$" />
-      <package value="github.com/wneessen/apg.go" />
+      <package value="github.com/wneessen/apg-go" />
       <directory value="$PROJECT_DIR$" />
+      <filePath value="$PROJECT_DIR$" />
       <method v="2" />
     </configuration>
     <configuration name="Run Application (with params)" type="GoApplicationRunConfiguration" factoryName="Go Application">
@@ -137,38 +139,38 @@
       <working_directory value="$PROJECT_DIR$" />
       <parameters value="-m 20 -x 20 -C" />
       <kind value="PACKAGE" />
-      <filePath value="$PROJECT_DIR$" />
-      <package value="github.com/wneessen/apg.go" />
+      <package value="github.com/wneessen/apg-go" />
       <directory value="$PROJECT_DIR$" />
+      <filePath value="$PROJECT_DIR$" />
       <method v="2" />
     </configuration>
     <configuration name="Run Application" type="GoApplicationRunConfiguration" factoryName="Go Application">
       <module name="apg.go" />
       <working_directory value="$PROJECT_DIR$" />
       <kind value="PACKAGE" />
-      <filePath value="$PROJECT_DIR$" />
-      <package value="github.com/wneessen/apg.go" />
+      <package value="github.com/wneessen/apg-go" />
       <directory value="$PROJECT_DIR$" />
+      <filePath value="$PROJECT_DIR$" />
       <method v="2" />
     </configuration>
     <configuration name="Benchmark Application" type="GoTestRunConfiguration" factoryName="Go Test">
       <module name="apg.go" />
       <working_directory value="$PROJECT_DIR$" />
-      <framework value="gobench" />
       <kind value="PACKAGE" />
-      <package value="github.com/wneessen/apg.go" />
+      <package value="github.com/wneessen/apg-go" />
       <directory value="$PROJECT_DIR$" />
       <filePath value="$PROJECT_DIR$" />
+      <framework value="gobench" />
       <method v="2" />
     </configuration>
     <configuration name="Test Application" type="GoTestRunConfiguration" factoryName="Go Test">
       <module name="apg.go" />
       <working_directory value="$PROJECT_DIR$" />
-      <framework value="gotest" />
       <kind value="PACKAGE" />
-      <package value="github.com/wneessen/apg.go" />
+      <package value="github.com/wneessen/apg-go" />
       <directory value="$PROJECT_DIR$" />
       <filePath value="$PROJECT_DIR$" />
+      <framework value="gotest" />
       <method v="2" />
     </configuration>
     <list>
diff --git a/README.md b/README.md
index 1e9b92f..e61faa0 100644
--- a/README.md
+++ b/README.md
@@ -85,9 +85,9 @@ $ sudo cp apg /usr/local/bin/apg
 ## CLI parameters
 _apg.go_ replicates some of the parameters of the original APG. Some parameters are different though:
 
-- ```-m <length>```: The minimum length of the password to be generated (Default: 20)
+- ```-m <length>```: The minimum length of the password to be generated (Default: 12)
 - ```-x <length>```: The maximum length of the password to be generated (Default: 20)
-- ```-n <number of passwords>```: The amount of passwords to be generated (Default: 1)
+- ```-n <number of passwords>```: The amount of passwords to be generated (Default: 6)
 - ```-E <list of characters>```: Do not use the specified characters in generated passwords
 - ```-M <[LUNSHClunshc]>```: New style password parameters (upper-case enables, lower-case disables)
 - ```-L```: Use lower-case characters in passwords (Default: on)
diff --git a/apg_test.go b/apg_test.go
index 5e8183f..8b59a9c 100644
--- a/apg_test.go
+++ b/apg_test.go
@@ -1,6 +1,8 @@
 package main
 
-import "testing"
+import (
+	"testing"
+)
 
 var config Config
 
@@ -51,6 +53,44 @@ func TestGetRandNum(t *testing.T) {
 	}
 }
 
+// Test Pwlength
+func TestGenLength(t *testing.T) {
+	testTable := []struct {
+		testName  string
+		minLength int
+		maxLength int
+	}{
+		{"pwLength defaults", DefaultMinLenght, DefaultMaxLenght},
+		{"pwLength 0 to 1", 0, 1},
+		{"pwLength 1 to 10", 0, 10},
+		{"pwLength 10 to 100", 10, 100},
+	}
+
+	charRange := getCharRange(&config)
+	for _, testCase := range testTable {
+		t.Run(testCase.testName, func(t *testing.T) {
+			config.minPassLen = testCase.minLength
+			config.maxPassLen = testCase.maxLength
+			pwLength := getPwLengthFromParams(&config)
+			for i := 0; i < 1000; i++ {
+				pwString, err := getRandChar(&charRange, pwLength)
+				if err != nil {
+					t.Errorf("getRandChar returned an error: %q", err)
+				}
+				retLen := len(pwString)
+				if retLen > testCase.maxLength {
+					t.Errorf("Generated password length too long. GivenMin %v, GivenMax: %v, Returned length %v",
+						testCase.minLength, testCase.maxLength, retLen)
+				}
+				if retLen < testCase.minLength {
+					t.Errorf("Generated password length too short. GivenMin %v, GivenMax: %v, Returned length %v",
+						testCase.minLength, testCase.maxLength, retLen)
+				}
+			}
+		})
+	}
+}
+
 // Test getRandChar
 func TestGetRandChar(t *testing.T) {
 	t.Run("return_value_is_A_B_or_C", func(t *testing.T) {
diff --git a/config.go b/config.go
index 801a89c..f90664d 100644
--- a/config.go
+++ b/config.go
@@ -18,9 +18,9 @@ func parseFlags() Config {
 	flag.BoolVar(&config.spellPassword, "l", false, "Spell generated password")
 	flag.BoolVar(&config.humanReadable, "H", false, "Generate human-readable passwords")
 	flag.BoolVar(&config.showVersion, "v", false, "Show version")
-	flag.IntVar(&config.minPassLen, "m", DefaultPwLenght, "Minimum password length")
-	flag.IntVar(&config.maxPassLen, "x", DefaultPwLenght, "Maxiumum password length")
-	flag.IntVar(&config.numOfPass, "n", 1, "Number of passwords to generate")
+	flag.IntVar(&config.minPassLen, "m", DefaultMinLenght, "Minimum password length")
+	flag.IntVar(&config.maxPassLen, "x", DefaultMaxLenght, "Maxiumum password length")
+	flag.IntVar(&config.numOfPass, "n", 6, "Number of passwords to generate")
 	flag.StringVar(&config.excludeChars, "E", "", "Exclude list of characters from generated password")
 	flag.StringVar(&config.newStyleModes, "M", "",
 		"New style password parameters (higher priority than single parameters)")
@@ -60,15 +60,16 @@ func parseParams(config *Config) {
 
 // Get the password length from the given cli flags
 func getPwLengthFromParams(config *Config) int {
-	pwLength := config.minPassLen
-	if pwLength < config.minPassLen {
-		pwLength = config.minPassLen
+	if config.minPassLen > config.maxPassLen {
+		config.maxPassLen = config.minPassLen
 	}
-	if pwLength > config.maxPassLen {
-		pwLength = config.maxPassLen
+	lenDiff := config.maxPassLen - config.minPassLen + 1
+	randAdd, err := getRandNum(lenDiff)
+	if err != nil {
+		log.Fatalf("Failed to generated password length: %v", err)
 	}
 
-	return pwLength
+	return config.minPassLen + randAdd
 }
 
 // Parse the new style parameters
diff --git a/go.mod b/go.mod
index dd33c59..b6933e8 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,3 @@
-module github.com/wneessen/apg.go
+module github.com/wneessen/apg-go
 
 go 1.16