Add checks to X509_NAME_oneline()
authorDr. Stephen Henson <steve@openssl.org>
Thu, 28 Apr 2016 18:45:44 +0000 (19:45 +0100)
committerDr. Stephen Henson <steve@openssl.org>
Fri, 29 Apr 2016 18:55:56 +0000 (19:55 +0100)
Sanity check field lengths and sums to avoid potential overflows and reject
excessively large X509_NAME structures.

Issue reported by Guido Vranken.

Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 9b08619cb45e75541809b1154c90e1a00450e537)

Conflicts:
crypto/x509/x509.h
crypto/x509/x509_err.c

crypto/x509/x509.h
crypto/x509/x509_err.c
crypto/x509/x509_obj.c

index a491174..bd600de 100644 (file)
@@ -1281,6 +1281,7 @@ void ERR_load_X509_strings(void);
 # define X509_R_LOADING_CERT_DIR                          103
 # define X509_R_LOADING_DEFAULTS                          104
 # define X509_R_METHOD_NOT_SUPPORTED                      124
+# define X509_R_NAME_TOO_LONG                             134
 # define X509_R_NO_CERT_SET_FOR_US_TO_VERIFY              105
 # define X509_R_PUBLIC_KEY_DECODE_ERROR                   125
 # define X509_R_PUBLIC_KEY_ENCODE_ERROR                   126
index 61a19f7..a2b8b7f 100644 (file)
@@ -145,6 +145,7 @@ static ERR_STRING_DATA X509_str_reasons[] = {
     {ERR_REASON(X509_R_LOADING_CERT_DIR), "loading cert dir"},
     {ERR_REASON(X509_R_LOADING_DEFAULTS), "loading defaults"},
     {ERR_REASON(X509_R_METHOD_NOT_SUPPORTED), "method not supported"},
+    {ERR_REASON(X509_R_NAME_TOO_LONG), "name too long"},
     {ERR_REASON(X509_R_NO_CERT_SET_FOR_US_TO_VERIFY),
      "no cert set for us to verify"},
     {ERR_REASON(X509_R_PUBLIC_KEY_DECODE_ERROR), "public key decode error"},
index 500c9df..f7daac2 100644 (file)
 #include <openssl/x509.h>
 #include <openssl/buffer.h>
 
+/*
+ * Limit to ensure we don't overflow: much greater than
+ * anything enountered in practice.
+ */
+
+#define NAME_ONELINE_MAX    (1024 * 1024)
+
 char *X509_NAME_oneline(X509_NAME *a, char *buf, int len)
 {
     X509_NAME_ENTRY *ne;
@@ -112,6 +119,10 @@ char *X509_NAME_oneline(X509_NAME *a, char *buf, int len)
 
         type = ne->value->type;
         num = ne->value->length;
+        if (num > NAME_ONELINE_MAX) {
+            X509err(X509_F_X509_NAME_ONELINE, X509_R_NAME_TOO_LONG);
+            goto end;
+        }
         q = ne->value->data;
 #ifdef CHARSET_EBCDIC
         if (type == V_ASN1_GENERALSTRING ||
@@ -156,6 +167,10 @@ char *X509_NAME_oneline(X509_NAME *a, char *buf, int len)
 
         lold = l;
         l += 1 + l1 + 1 + l2;
+        if (l > NAME_ONELINE_MAX) {
+            X509err(X509_F_X509_NAME_ONELINE, X509_R_NAME_TOO_LONG);
+            goto end;
+        }
         if (b != NULL) {
             if (!BUF_MEM_grow(b, l + 1))
                 goto err;
@@ -208,7 +223,7 @@ char *X509_NAME_oneline(X509_NAME *a, char *buf, int len)
     return (p);
  err:
     X509err(X509_F_X509_NAME_ONELINE, ERR_R_MALLOC_FAILURE);
-    if (b != NULL)
-        BUF_MEM_free(b);
+ end:
+    BUF_MEM_free(b);
     return (NULL);
 }