Don't run the permissions checks on non-Unix platforms

This is way too annoying on Windows systems.

Author: jedisct1

dnscrypt-proxy/common.go

@@ -6,12 +6,9 @@ import (
 	"errors"
 	"net"
 	"os"
-	"path"
 	"strconv"
 	"strings"
 	"unicode"
-
-	"github.com/jedisct1/dlog"
 )
 
 type CryptoConstruction uint16
@@ -167,31 +164,3 @@ func ReadTextFile(filename string) (string, error) {
 }
 
 func isDigit(b byte) bool { return b >= '0' && b <= '9' }
-
-func maybeWritableByOtherUsers(p string) (bool, string, error) {
-	p = path.Clean(p)
-	for p != "/" && p != "." {
-		st, err := os.Stat(p)
-		if err != nil {
-			return false, p, err
-		}
-		mode := st.Mode()
-		if mode.Perm()&2 != 0 && !(st.IsDir() && mode&os.ModeSticky == os.ModeSticky) {
-			return true, p, nil
-		}
-		p = path.Dir(p)
-	}
-	return false, "", nil
-}
-
-func WarnIfMaybeWritableByOtherUsers(p string) {
-	if ok, px, err := maybeWritableByOtherUsers(p); ok {
-		if px == p {
-			dlog.Criticalf("[%s] is writable by other system users - If this is not intentional, it is recommended to fix the access permissions", p)
-		} else {
-			dlog.Warnf("[%s] can be modified by other system users because [%s] is writable by other users - If this is not intentional, it is recommended to fix the access permissions", p, px)
-		}
-	} else if err != nil {
-		dlog.Warnf("Error while checking if [%s] is accessible: [%s] : [%s]", p, px, err)
-	}
-}

dnscrypt-proxy/permcheck_others.go

@@ -0,0 +1,7 @@
+//go:build !unix
+
+package main
+
+func WarnIfMaybeWritableByOtherUsers(p string) {
+	// No-op
+}

dnscrypt-proxy/permcheck_unix.go

@@ -0,0 +1,36 @@
+package main
+
+import (
+	"os"
+	"path"
+
+	"github.com/jedisct1/dlog"
+)
+
+func maybeWritableByOtherUsers(p string) (bool, string, error) {
+	p = path.Clean(p)
+	for p != "/" && p != "." {
+		st, err := os.Stat(p)
+		if err != nil {
+			return false, p, err
+		}
+		mode := st.Mode()
+		if mode.Perm()&2 != 0 && !(st.IsDir() && mode&os.ModeSticky == os.ModeSticky) {
+			return true, p, nil
+		}
+		p = path.Dir(p)
+	}
+	return false, "", nil
+}
+
+func WarnIfMaybeWritableByOtherUsers(p string) {
+	if ok, px, err := maybeWritableByOtherUsers(p); ok {
+		if px == p {
+			dlog.Criticalf("[%s] is writable by other system users - If this is not intentional, it is recommended to fix the access permissions", p)
+		} else {
+			dlog.Warnf("[%s] can be modified by other system users because [%s] is writable by other users - If this is not intentional, it is recommended to fix the access permissions", p, px)
+		}
+	} else if err != nil {
+		dlog.Warnf("Error while checking if [%s] is accessible: [%s] : [%s]", p, px, err)
+	}
+}