Move and rename decode_escaped_string()

This function decodes something different from the usual c-escaped
format.

It is only used in controller authorization.

3 files changed, 4 insertions, 79 deletions

diff --git a/src/feature/control/control_auth.c b/src/feature/control/control_auth.c
index 927115a308..8204290489 100644
--- a/src/feature/control/control_auth.c
+++ b/src/feature/control/control_auth.c
@@ -17,6 +17,7 @@
 #include "lib/crypt_ops/crypto_rand.h"
 #include "lib/crypt_ops/crypto_util.h"
 #include "lib/encoding/confline.h"
+#include "lib/encoding/qstring.h"
 
 #include "lib/crypt_ops/crypto_s2k.h"
 
@@ -149,8 +150,8 @@ handle_control_authchallenge(control_connection_t *conn, uint32_t len,
   cp += strspn(cp, " \t\n\r");
   if (*cp == '"') {
     const char *newcp =
-      decode_escaped_string(cp, len - (cp - body),
-                            &client_nonce, &client_nonce_len);
+      decode_qstring(cp, len - (cp - body),
+                     &client_nonce, &client_nonce_len);
     if (newcp == NULL) {
       connection_write_str_to_buf("513 Invalid quoted client nonce\r\n",
                                   conn);
@@ -275,7 +276,7 @@ handle_control_authenticate(control_connection_t *conn, uint32_t len,
       return 0;
     }
   } else {
-    if (!decode_escaped_string(body, len, &password, &password_len)) {
+    if (!decode_qstring(body, len, &password, &password_len)) {
       connection_write_str_to_buf("551 Invalid quoted string.  You need "
             "to put the password in double quotes.\r\n", conn);
       connection_mark_for_close(TO_CONN(conn));
diff --git a/src/feature/control/control_fmt.c b/src/feature/control/control_fmt.c
index 427f4288fc..b2ab4f10bb 100644
--- a/src/feature/control/control_fmt.c
+++ b/src/feature/control/control_fmt.c
@@ -305,80 +305,6 @@ send_control_done(control_connection_t *conn)
   connection_write_str_to_buf("250 OK\r\n", conn);
 }
 
-/** If the first <b>in_len_max</b> characters in <b>start</b> contain a
- * double-quoted string with escaped characters, return the length of that
- * string (as encoded, including quotes).  Otherwise return -1. */
-static inline int
-get_escaped_string_length(const char *start, size_t in_len_max,
-                          int *chars_out)
-{
-  const char *cp, *end;
-  int chars = 0;
-
-  if (*start != '\"')
-    return -1;
-
-  cp = start+1;
-  end = start+in_len_max;
-
-  /* Calculate length. */
-  while (1) {
-    if (cp >= end) {
-      return -1; /* Too long. */
-    } else if (*cp == '\\') {
-      if (++cp == end)
-        return -1; /* Can't escape EOS. */
-      ++cp;
-      ++chars;
-    } else if (*cp == '\"') {
-      break;
-    } else {
-      ++cp;
-      ++chars;
-    }
-  }
-  if (chars_out)
-    *chars_out = chars;
-  return (int)(cp - start+1);
-}
-
-/** Given a pointer to a string starting at <b>start</b> containing
- * <b>in_len_max</b> characters, decode a string beginning with one double
- * quote, containing any number of non-quote characters or characters escaped
- * with a backslash, and ending with a final double quote.  Place the resulting
- * string (unquoted, unescaped) into a newly allocated string in *<b>out</b>;
- * store its length in <b>out_len</b>.  On success, return a pointer to the
- * character immediately following the escaped string.  On failure, return
- * NULL. */
-const char *
-decode_escaped_string(const char *start, size_t in_len_max,
-                   char **out, size_t *out_len)
-{
-  const char *cp, *end;
-  char *outp;
-  int len, n_chars = 0;
-
-  len = get_escaped_string_length(start, in_len_max, &n_chars);
-  if (len<0)
-    return NULL;
-
-  end = start+len-1; /* Index of last quote. */
-  tor_assert(*end == '\"');
-  outp = *out = tor_malloc(len+1);
-  *out_len = n_chars;
-
-  cp = start+1;
-  while (cp < end) {
-    if (*cp == '\\')
-      ++cp;
-    *outp++ = *cp++;
-  }
-  *outp = '\0';
-  tor_assert((outp - *out) == (int)*out_len);
-
-  return end+1;
-}
-
 /** Return a longname the node whose identity is <b>id_digest</b>. If
  * node_get_by_id() returns NULL, base 16 encoding of <b>id_digest</b> is
  * returned instead.
diff --git a/src/feature/control/control_fmt.h b/src/feature/control/control_fmt.h
index 08acf85181..8bbbaa95d0 100644
--- a/src/feature/control/control_fmt.h
+++ b/src/feature/control/control_fmt.h
@@ -25,8 +25,6 @@ char *circuit_describe_status_for_controller(origin_circuit_t *circ);
 
 size_t write_escaped_data(const char *data, size_t len, char **out);
 size_t read_escaped_data(const char *data, size_t len, char **out);
-const char *decode_escaped_string(const char *start, size_t in_len_max,
-                                  char **out, size_t *out_len);
 void send_control_done(control_connection_t *conn);
 
 MOCK_DECL(const char *, node_describe_longname_by_id,(const char *id_digest));