X-Git-Url: https://ruderich.org/simon/gitweb/?p=nsscash%2Fnsscash.git;a=blobdiff_plain;f=passwd.go;h=7364639d8e2c3581fe71030b85fac22cfee58456;hp=2698765212e0975738ebc8d8273140daee528816;hb=1b9065b13eeeb40ecf6759bb065f0a039d2a9996;hpb=c6b898ea9ab372c58c59658c2acf17ea831d71db

diff --git a/passwd.go b/passwd.go
index 2698765..7364639 100644
--- a/passwd.go
+++ b/passwd.go
@@ -23,6 +23,7 @@ import (
 	"encoding/binary"
 	"fmt"
 	"io"
+	"math"
 	"sort"
 	"strconv"
 	"strings"
@@ -53,6 +54,11 @@ func ParsePasswds(r io.Reader) ([]Passwd, error) {
 		t, err := s.ReadString('\n')
 		if err != nil {
 			if err == io.EOF {
+				if t != "" {
+					return nil, fmt.Errorf(
+						"no newline in last line: %q",
+						t)
+				}
 				break
 			}
 			return nil, err
@@ -86,7 +92,7 @@ func ParsePasswds(r io.Reader) ([]Passwd, error) {
 	return res, nil
 }
 
-func SerializePasswd(p Passwd) []byte {
+func SerializePasswd(p Passwd) ([]byte, error) {
 	// Concatenate all (NUL-terminated) strings and store the offsets
 	var data bytes.Buffer
 	data.Write([]byte(p.Name))
@@ -103,6 +109,11 @@ func SerializePasswd(p Passwd) []byte {
 	offShell := uint16(data.Len())
 	data.Write([]byte(p.Shell))
 	data.WriteByte(0)
+	// Ensure the offsets can fit the length of this entry
+	if data.Len() > math.MaxUint16 {
+		return nil, fmt.Errorf("passwd too large to serialize: %v, %v",
+			data.Len(), p)
+	}
 	size := uint16(data.Len())
 
 	var res bytes.Buffer // serialized result
@@ -138,7 +149,7 @@ func SerializePasswd(p Passwd) []byte {
 	// struct are 8 byte aligned
 	alignBufferTo(&res, 8)
 
-	return res.Bytes()
+	return res.Bytes(), nil
 }
 
 func SerializePasswds(w io.Writer, pws []Passwd) error {
@@ -148,7 +159,11 @@ func SerializePasswds(w io.Writer, pws []Passwd) error {
 	for _, p := range pws {
 		// TODO: warn about duplicate entries
 		offsets[p] = uint64(data.Len())
-		data.Write(SerializePasswd(p))
+		x, err := SerializePasswd(p)
+		if err != nil {
+			return err
+		}
+		data.Write(x)
 	}
 
 	// Copy to prevent sorting from modifying the argument