From 114b31ab5b7e6965b629697020a7ce4b6cea340e Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Mon, 13 Aug 2018 10:35:52 +0200
Subject: [PATCH] Curl_ntlm_core_mk_nt_hash: return error on too long password

... since it would cause an integer overflow if longer than (max size_t
/ 2).

This is CVE-2018-14618

Bug: https://curl.haxx.se/docs/CVE-2018-14618.html
Closes #2756
Reported-by: Zhaoyang Wu

Upstream-commit: 57d299a499155d4b327e341c6024e293b0418243
Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
 lib/curl_ntlm_core.c | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/lib/curl_ntlm_core.c b/lib/curl_ntlm_core.c
index e896276..e5c785d 100644
--- a/lib/curl_ntlm_core.c
+++ b/lib/curl_ntlm_core.c
@@ -143,6 +143,15 @@
 #define NTLMv2_BLOB_SIGNATURE "\x01\x01\x00\x00"
 #define NTLMv2_BLOB_LEN       (44 -16 + ntlm->target_info_len + 4)
 
+#ifndef SIZE_T_MAX
+/* some limits.h headers have this defined, some don't */
+#if defined(SIZEOF_SIZE_T) && (SIZEOF_SIZE_T > 4)
+#define SIZE_T_MAX 18446744073709551615U
+#else
+#define SIZE_T_MAX 4294967295U
+#endif
+#endif
+
 /*
 * Turns a 56-bit key into being 64-bit wide.
 */
@@ -557,8 +566,11 @@ CURLcode Curl_ntlm_core_mk_nt_hash(struct Curl_easy *data,
                                    unsigned char *ntbuffer /* 21 bytes */)
 {
   size_t len = strlen(password);
-  unsigned char *pw = len ? malloc(len * 2) : strdup("");
+  unsigned char *pw;
   CURLcode result;
+  if(len > SIZE_T_MAX/2) /* avoid integer overflow */
+    return CURLE_OUT_OF_MEMORY;
+  pw = len ? malloc(len * 2) : strdup("");
   if(!pw)
     return CURLE_OUT_OF_MEMORY;
 
@@ -646,15 +658,6 @@ CURLcode Curl_hmac_md5(const unsigned char *key, unsigned int keylen,
   return CURLE_OK;
 }
 
-#ifndef SIZE_T_MAX
-/* some limits.h headers have this defined, some don't */
-#if defined(SIZEOF_SIZE_T) && (SIZEOF_SIZE_T > 4)
-#define SIZE_T_MAX 18446744073709551615U
-#else
-#define SIZE_T_MAX 4294967295U
-#endif
-#endif
-
 /* This creates the NTLMv2 hash by using NTLM hash as the key and Unicode
  * (uppercase UserName + Domain) as the data
  */
-- 
2.17.1