Pass characters to be escaped to tor_escape_str_for_socks_arg().

This is in preparation for using tor_escape_str_for_socks_arg() to
escape server-side pluggable transport parameters.

src/common/util.c

@@ -1223,17 +1223,15 @@ escaped(const char *s)
   return escaped_val_;
 }
 
-/** Escape every ";" or "\" character of <b>string</b>. Use
- *  <b>escape_char</b> as the character to use for escaping.
- *  The returned string is allocated on the heap and it's the
- *  responsibility of the caller to free it. */
+/** Escape every character of <b>string</b> that is in
+ *  <b>chars_to_escape</b>. The returned string is allocated on the
+ *  heap and it's the responsibility of the caller to free it. */
 char *
-tor_escape_str_for_socks_arg(const char *string)
+tor_escape_str_for_socks_arg(const char *string, const char *chars_to_escape)
 {
   char *new_string = NULL;
   char *new_cp = NULL;
   size_t length, new_length;
-  static const char *chars_to_escape = ";\\";
 
   tor_assert(string);
 

src/common/util.h

@@ -231,7 +231,8 @@ int tor_digest256_is_zero(const char *digest);
 char *esc_for_log(const char *string) ATTR_MALLOC;
 const char *escaped(const char *string);
 
-char *tor_escape_str_for_socks_arg(const char *string);
+char *tor_escape_str_for_socks_arg(const char *string,
+                                   const char *chars_to_escape);
 
 struct smartlist_t;
 int tor_vsscanf(const char *buf, const char *pattern, va_list ap) \

src/or/transports.c

@@ -1440,7 +1440,7 @@ pt_stringify_socks_args(const smartlist_t *socks_args)
 
   SMARTLIST_FOREACH_BEGIN(socks_args, const char *, s) {
     /* Escape ';' and '\'. */
-    escaped_string = tor_escape_str_for_socks_arg(s);
+    escaped_string = tor_escape_str_for_socks_arg(s, ";\\");
     if (!escaped_string)
       goto done;
 

src/test/test_util.c

@@ -803,30 +803,30 @@ test_util_escape_string_socks(void)
   char *escaped_string = NULL;
 
   /** Simple backslash escape. */
-  escaped_string = tor_escape_str_for_socks_arg("This is a backslash: \\");
+  escaped_string = tor_escape_str_for_socks_arg("This is a backslash: \\", ";\\");
   test_assert(escaped_string);
   test_streq(escaped_string, "This is a backslash: \\\\");
   tor_free(escaped_string);
 
   /** Simple semicolon escape. */
-  escaped_string = tor_escape_str_for_socks_arg("First rule: Do not use ;");
+  escaped_string = tor_escape_str_for_socks_arg("First rule: Do not use ;", ";\\");
   test_assert(escaped_string);
   test_streq(escaped_string, "First rule: Do not use \\;");
   tor_free(escaped_string);
 
   /** Empty string. */
-  escaped_string = tor_escape_str_for_socks_arg("");
+  escaped_string = tor_escape_str_for_socks_arg("", ";\\");
   test_assert(escaped_string);
   test_streq(escaped_string, "");
   tor_free(escaped_string);
 
   /** Escape all characters. */
-  escaped_string = tor_escape_str_for_socks_arg(";\\;\\");
+  escaped_string = tor_escape_str_for_socks_arg(";\\;\\", ";\\");
   test_assert(escaped_string);
   test_streq(escaped_string, "\\;\\\\\\;\\\\");
   tor_free(escaped_string);
 
-  escaped_string = tor_escape_str_for_socks_arg(";");
+  escaped_string = tor_escape_str_for_socks_arg(";", ";\\");
   test_assert(escaped_string);
   test_streq(escaped_string, "\\;");
   tor_free(escaped_string);