1 files changed, 40 insertions, 38 deletions

diff --git a/lib/escape.c b/lib/escape.c
index 7121db31..2bea145f 100644
--- a/lib/escape.c
+++ b/lib/escape.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -79,82 +79,83 @@ char *curl_unescape(const char *string, int length)
 char *curl_easy_escape(struct Curl_easy *data, const char *string,
                        int inlength)
 {
-  size_t alloc;
-  char *ns;
-  char *testing_ptr = NULL;
-  size_t newlen;
-  size_t strindex = 0;
   size_t length;
   CURLcode result;
+  struct dynbuf d;
 
   if(inlength < 0)
     return NULL;
 
-  alloc = (inlength?(size_t)inlength:strlen(string)) + 1;
-  newlen = alloc;
+  Curl_dyn_init(&d, CURL_MAX_INPUT_LENGTH);
 
-  ns = malloc(alloc);
-  if(!ns)
-    return NULL;
+  length = (inlength?(size_t)inlength:strlen(string));
+  if(!length)
+    return strdup("");
 
-  length = alloc-1;
   while(length--) {
     unsigned char in = *string; /* we need to treat the characters unsigned */
 
-    if(Curl_isunreserved(in))
-      /* just copy this */
-      ns[strindex++] = in;
+    if(Curl_isunreserved(in)) {
+      /* append this */
+      if(Curl_dyn_addn(&d, &in, 1))
+        return NULL;
+    }
     else {
       /* encode it */
-      newlen += 2; /* the size grows with two, since this'll become a %XX */
-      if(newlen > alloc) {
-        alloc *= 2;
-        testing_ptr = Curl_saferealloc(ns, alloc);
-        if(!testing_ptr)
-          return NULL;
-        ns = testing_ptr;
-      }
-
+      char encoded[4];
       result = Curl_convert_to_network(data, (char *)&in, 1);
       if(result) {
         /* Curl_convert_to_network calls failf if unsuccessful */
-        free(ns);
+        Curl_dyn_free(&d);
         return NULL;
       }
 
-      msnprintf(&ns[strindex], 4, "%%%02X", in);
-
-      strindex += 3;
+      msnprintf(encoded, sizeof(encoded), "%%%02X", in);
+      if(Curl_dyn_add(&d, encoded))
+        return NULL;
     }
     string++;
   }
-  ns[strindex] = 0; /* terminate it */
-  return ns;
+
+  return Curl_dyn_ptr(&d);
 }
 
 /*
  * Curl_urldecode() URL decodes the given string.
  *
- * Optionally detects control characters (byte codes lower than 32) in the
- * data and rejects such data.
- *
  * Returns a pointer to a malloced string in *ostring with length given in
  * *olen. If length == 0, the length is assumed to be strlen(string).
  *
  * 'data' can be set to NULL but then this function can't convert network
  * data to host for non-ascii.
+ *
+ * ctrl options:
+ * - REJECT_NADA: accept everything
+ * - REJECT_CTRL: rejects control characters (byte codes lower than 32) in
+ *                the data
+ * - REJECT_ZERO: rejects decoded zero bytes
+ *
+ * The values for the enum starts at 2, to make the assert detect legacy
+ * invokes that used TRUE/FALSE (0 and 1).
  */
+
 CURLcode Curl_urldecode(struct Curl_easy *data,
                         const char *string, size_t length,
                         char **ostring, size_t *olen,
-                        bool reject_ctrl)
+                        enum urlreject ctrl)
 {
-  size_t alloc = (length?length:strlen(string)) + 1;
-  char *ns = malloc(alloc);
+  size_t alloc;
+  char *ns;
   size_t strindex = 0;
   unsigned long hex;
   CURLcode result = CURLE_OK;
 
+  DEBUGASSERT(string);
+  DEBUGASSERT(ctrl >= REJECT_NADA); /* crash on TRUE/FALSE */
+
+  alloc = (length?length:strlen(string)) + 1;
+  ns = malloc(alloc);
+
   if(!ns)
     return CURLE_OUT_OF_MEMORY;
 
@@ -186,7 +187,8 @@ CURLcode Curl_urldecode(struct Curl_easy *data,
       alloc -= 2;
     }
 
-    if(reject_ctrl && (in < 0x20)) {
+    if(((ctrl == REJECT_CTRL) && (in < 0x20)) ||
+       ((ctrl == REJECT_ZERO) && (in == 0))) {
       free(ns);
       return CURLE_URL_MALFORMAT;
     }
@@ -220,7 +222,7 @@ char *curl_easy_unescape(struct Curl_easy *data, const char *string,
     size_t inputlen = length;
     size_t outputlen;
     CURLcode res = Curl_urldecode(data, string, inputlen, &str, &outputlen,
-                                  FALSE);
+                                  REJECT_NADA);
     if(res)
       return NULL;