Added unit tests for auth.go: AuthUserByToken

Signed-off-by: Russ Magee <rmagee@gmail.com>

auth.go

@@ -30,6 +30,9 @@ import (
 // Verify a password against system standard shadow file
 // Note auxilliary fields for expiry policy are *not* inspected.
 func VerifyPass(reader func(string) ([]byte, error), user, password string) (bool, error) {
+	if reader == nil {
+		reader = ioutil.ReadFile // dependency injection hides that this is required
+	}
 	passlib.UseDefaults(passlib.Defaults20180601)
 	pwFileData, e := reader("/etc/shadow")
 	if e != nil {
@@ -70,8 +73,11 @@ func VerifyPass(reader func(string) ([]byte, error), user, password string) (boo
 // This checks /etc/xs.passwd for auth info, and system /etc/passwd
 // to cross-check the user actually exists.
 // nolint: gocyclo
-func AuthUserByPasswd(username string, auth string, fname string) (valid bool, allowedCmds string) {
-	b, e := ioutil.ReadFile(fname) // nolint: gosec
+func AuthUserByPasswd(reader func(string) ([]byte, error), userlookup func(string) (*user.User, error), username string, auth string, fname string) (valid bool, allowedCmds string) {
+	if reader == nil {
+		reader = ioutil.ReadFile // dependency injection hides that this is required
+	}
+	b, e := reader(fname) // nolint: gosec
 	if e != nil {
 		valid = false
 		log.Printf("ERROR: Cannot read %s!\n", fname)
@@ -115,7 +121,8 @@ func AuthUserByPasswd(username string, auth string, fname string) (valid bool, a
 	r = nil
 	runtime.GC()
 
-	if !userExistsOnSystem(username) {
+	_, userErr := userlookup(username)
+	if userErr != nil {
 		valid = false
 	}
 	return
@@ -123,24 +130,26 @@ func AuthUserByPasswd(username string, auth string, fname string) (valid bool, a
 
 // ------------- End xs-local passwd auth routine(s) -----------
 
-func userExistsOnSystem(who string) bool {
-	_, userErr := user.Lookup(who)
-	return userErr == nil
-}
-
 // AuthUserByToken checks user login information against an auth token.
 // Auth tokens are stored in each user's $HOME/.xs_id and are requested
 // via the -g option.
 // The function also check system /etc/passwd to cross-check the user
 // actually exists.
-func AuthUserByToken(username string, connhostname string, auth string) (valid bool) {
+func AuthUserByToken(reader func(string) ([]byte, error), userlookup func(string) (*user.User, error), username string, connhostname string, auth string) (valid bool) {
+	if reader == nil {
+		reader = ioutil.ReadFile // dependency injection hides that this is required
+	}
+	if userlookup == nil {
+		userlookup = user.Lookup // again for dependency injection as dep is now hidden
+	}
+
 	auth = strings.TrimSpace(auth)
-	u, ue := user.Lookup(username)
+	u, ue := userlookup(username)
 	if ue != nil {
 		return false
 	}
 
-	b, e := ioutil.ReadFile(fmt.Sprintf("%s/.xs_id", u.HomeDir))
+	b, e := reader(fmt.Sprintf("%s/.xs_id", u.HomeDir))
 	if e != nil {
 		log.Printf("INFO: Cannot read %s/.xs_id\n", u.HomeDir)
 		return false
@@ -167,7 +176,8 @@ func AuthUserByToken(username string, connhostname string, auth string) (valid b
 			break
 		}
 	}
-	if !userExistsOnSystem(username) {
+	_, userErr := userlookup(username)
+	if userErr != nil {
 		valid = false
 	}
 	return

auth_test.go

@@ -2,6 +2,9 @@ package xs
 
 import (
 	"errors"
+	"fmt"
+	"os/user"
+	"strings"
 	"testing"
 )
 
@@ -16,16 +19,40 @@ var (
 joebloggs:$6$F.0IXOrb0w0VJHG1$3O4PYyng7F3hlh42mbroEdQZvslybY5etPPiLMQJ1xosjABY.Q4xqAfyIfe03Du61ZjGQIt3nL0j12P9k1fsK/:18310:0:99999:7:::
 disableduser:!:18310::::::`
 
+	dummyAuthTokenFile = "hostA:abcdefg\nhostB:wxyz\n"
+
 	testGoodUsers = []userVerifs{
 		{"johndoe", "testpass", true},
 		{"joebloggs", "testpass2", true},
 		{"johndoe", "badpass", false},
 	}
+
+	userlookup_arg_u string
+	readfile_arg_f   string
 )
 
+func _mock_user_Lookup(username string) (*user.User, error) {
+	username = userlookup_arg_u
+	if username == "baduser" {
+		return &user.User{}, errors.New("bad user")
+	}
+	urec := &user.User{Uid: "1000", Gid: "1000", Username: username, Name: "Full Name", HomeDir: "/home/user"}
+	fmt.Printf("  [mock user rec:%v]\n", urec)
+	return urec, nil
+}
+
 func _mock_ioutil_ReadFile(f string) ([]byte, error) {
+	f = readfile_arg_f
+	if f == "/etc/shadow" {
+		fmt.Println("  [mocking ReadFile(\"/etc/shadow\")]")
 		return []byte(dummyShadowA), nil
 	}
+	if strings.Contains(f, "/.xs_id") {
+		fmt.Println("  [mocking ReadFile(\".xs_id\")]")
+		return []byte(dummyAuthTokenFile), nil
+	}
+	return []byte{}, errors.New("no readfile_arg_f supplied")
+}
 
 func _mock_ioutil_ReadFileEmpty(f string) ([]byte, error) {
 	return []byte{}, nil
@@ -36,6 +63,7 @@ func _mock_ioutil_ReadFileHasError(f string) ([]byte, error) {
 }
 
 func TestVerifyPass(t *testing.T) {
+	readfile_arg_f = "/etc/shadow"
 	for idx, rec := range testGoodUsers {
 		stat, e := VerifyPass(_mock_ioutil_ReadFile, rec.user, rec.passwd)
 		if rec.good && (!stat || e != nil) {
@@ -64,3 +92,43 @@ func TestVerifyPassFailsOnDisabledEntry(t *testing.T) {
 		t.Fatal("failed to fail on disabled user entry")
 	}
 }
+
+////
+
+func TestAuthUserByTokenFailsOnMissingEntryForHost(t *testing.T) {
+	stat := AuthUserByToken(_mock_ioutil_ReadFile, _mock_user_Lookup, "johndoe", "hostZ", "abcdefg")
+	if stat {
+		t.Fatal("failed to fail on missing/mismatched host entry")
+	}
+}
+
+func TestAuthUserByTokenFailsOnMissingEntryForUser(t *testing.T) {
+	stat := AuthUserByToken(_mock_ioutil_ReadFile, _mock_user_Lookup, "unkuser", "hostA", "abcdefg")
+	if stat {
+		t.Fatal("failed to fail on wrong user")
+	}
+}
+
+func TestAuthUserByTokenFailsOnUserLookupFailure(t *testing.T) {
+	userlookup_arg_u = "baduser"
+	stat := AuthUserByToken(_mock_ioutil_ReadFile, _mock_user_Lookup, "johndoe", "hostA", "abcdefg")
+	if stat {
+		t.Fatal("failed to fail with bad return from user.Lookup()")
+	}
+}
+
+func TestAuthUserByTokenFailsOnMismatchedTokenForUser(t *testing.T) {
+	stat := AuthUserByToken(_mock_ioutil_ReadFile, _mock_user_Lookup, "johndoe", "hostA", "badtoken")
+	if stat {
+		t.Fatal("failed to fail with valid user, bad token")
+	}
+}
+
+func TestAuthUserByTokenSucceedsWithMatchedUserAndToken(t *testing.T) {
+	userlookup_arg_u = "johndoe"
+	readfile_arg_f = "/.xs_id"
+	stat := AuthUserByToken(_mock_ioutil_ReadFile, _mock_user_Lookup, userlookup_arg_u, "hostA", "hostA:abcdefg")
+	if !stat {
+		t.Fatal("failed with valid user and token")
+	}
+}

xsd/xsd.go

@@ -708,14 +708,14 @@ func main() {
 
 				var valid bool
 				var allowedCmds string // Currently unused
-				if xs.AuthUserByToken(string(rec.Who()), string(rec.ConnHost()), string(rec.AuthCookie(true))) {
+				if xs.AuthUserByToken(ioutil.ReadFile, user.Lookup, string(rec.Who()), string(rec.ConnHost()), string(rec.AuthCookie(true))) {
 					valid = true
 				} else {
 					if useSystemPasswd {
 						//var passErr error
 						valid, _ /*passErr*/ = xs.VerifyPass(ioutil.ReadFile, string(rec.Who()), string(rec.AuthCookie(true)))
 					} else {
-						valid, allowedCmds = xs.AuthUserByPasswd(string(rec.Who()), string(rec.AuthCookie(true)), "/etc/xs.passwd")
+						valid, allowedCmds = xs.AuthUserByPasswd(ioutil.ReadFile, user.Lookup, string(rec.Who()), string(rec.AuthCookie(true)), "/etc/xs.passwd")
 					}
 				}