Wireshark · Ethereal-users: Re: [ethereal-users] LDAP Dissector

[Guy Harris <gharris@xxxxxxxxxxxx>]

On Wed, Aug 23, 2000 at 03:59:33PM -0700, Guy Harris wrote:
> Yes, I'll take a look at this; callers to
> "asn1_octet_string_value_decode()" must not assume that what they get
> back is a '\0'-terminated string (it's a counted string, and it's not
> even necessarily a character string - the ASN.1 dissector doesn't know
> whether it is, although its caller probably does), *and* must not assume
> that it gets back a non-null pointer.  The LDAP dissector is making both
> of those assumptions in some places....

Here's a patch to "packet-ldap.c" to fix that; users with source and
"patch" and compiler tools/necessary libraries can patch and rebuild,
users without any of those will probably have to wait for the next
release and the binary packages for that release.

Index: packet-ldap.c
===================================================================
RCS file: /usr/local/cvsroot/ethereal/packet-ldap.c,v
retrieving revision 1.15
diff -c -r1.15 packet-ldap.c
*** packet-ldap.c	2000/08/13 14:08:24	1.15
--- packet-ldap.c	2000/08/24 05:39:12
***************
*** 311,319 ****
  {
    guchar *string;
    guchar *string2;
!   gint string_length;
!   gint string2_length;
    guint string_bytes;
    int ret;
  
    ret = asn1_octet_string_decode(a, &string, &string_length, &string_bytes);
--- 311,320 ----
  {
    guchar *string;
    guchar *string2;
!   guint string_length;
!   guint string2_length;
    guint string_bytes;
+   char *filterp;
    int ret;
  
    ret = asn1_octet_string_decode(a, &string, &string_length, &string_bytes);
***************
*** 324,330 ****
      return ret;
    *filter_length += 2 + strlen(operation) + string_length + string2_length;
    *filter = g_realloc(*filter, *filter_length);
!   sprintf(*filter + strlen(*filter), "(%.*s%s%.*s)", string_length, string, operation, string2_length, string2);
    g_free(string);
    g_free(string2);
    return ASN1_ERR_NOERROR;
--- 325,344 ----
      return ret;
    *filter_length += 2 + strlen(operation) + string_length + string2_length;
    *filter = g_realloc(*filter, *filter_length);
!   filterp = *filter + strlen(*filter);
!   *filterp++ = '(';
!   if (string_length != 0) {
!   	memcpy(filterp, string, string_length);
!   	filterp += string_length;
!   }
!   strcpy(filterp, operation);
!   filterp += strlen(operation);
!   if (string2_length != 0) {
!   	memcpy(filterp, string2, string2_length);
!   	filterp += string2_length;
!   }
!   *filterp++ = ')';
!   *filterp = '\0';
    g_free(string);
    g_free(string2);
    return ASN1_ERR_NOERROR;
***************
*** 334,341 ****
  static int parse_filter_substrings(ASN1_SCK *a, char **filter, guint *filter_length)
  {
    guchar *end;
!   guchar *string = NULL;
!   gint string_length;
    guint string_bytes;
    guint seq_len;
    guint header_bytes;  
--- 348,356 ----
  static int parse_filter_substrings(ASN1_SCK *a, char **filter, guint *filter_length)
  {
    guchar *end;
!   guchar *string;
!   char *filterp;
!   guint string_length;
    guint string_bytes;
    guint seq_len;
    guint header_bytes;  
***************
*** 355,363 ****
    if (ret != ASN1_ERR_NOERROR)
      return ret;
  
!   *filter_length += 2 + 1 + strlen(string);
    *filter = g_realloc(*filter, *filter_length);
!   sprintf(*filter + strlen(*filter), "(%.*s=", string_length, string);
    g_free(string);
  
    /* Now decode seq_len's worth of octet strings. */
--- 370,386 ----
    if (ret != ASN1_ERR_NOERROR)
      return ret;
  
!   *filter_length += 2 + 1 + string_length;
    *filter = g_realloc(*filter, *filter_length);
!   
!   filterp = *filter + strlen(*filter);
!   *filterp++ = '(';
!   if (string_length != 0) {
!     memcpy(filterp, string, string_length);
!     filterp += string_length;
!   }
!   *filterp++ = '=';
!   *filterp = '\0';
    g_free(string);
  
    /* Now decode seq_len's worth of octet strings. */
***************
*** 384,402 ****
  
      /* If we have an 'any' component with a string value, we need to append
       * an extra asterisk before final component. */
!     if ((tag == 1) && (string_length > 0))
        any_valued = 1;
  
      if ( (tag == 1) || ((tag == 2) && any_valued) )
        (*filter_length)++;
!     *filter_length += strlen(string);
      *filter = g_realloc(*filter, *filter_length);
  
      if ( (tag == 1) || ((tag == 2) && any_valued) )
!       strcat(*filter, "*");
      if (tag == 2)
        any_valued = 0;
!     sprintf(*filter + strlen(*filter), "%.*s", string_length, string);
      g_free(string);
    }
  
--- 407,430 ----
  
      /* If we have an 'any' component with a string value, we need to append
       * an extra asterisk before final component. */
!     if ((tag == 1) && (string_length != 0))
        any_valued = 1;
  
      if ( (tag == 1) || ((tag == 2) && any_valued) )
        (*filter_length)++;
!     *filter_length += string_length;
      *filter = g_realloc(*filter, *filter_length);
  
+     filterp = *filter + strlen(*filter);
      if ( (tag == 1) || ((tag == 2) && any_valued) )
!       *filterp++ = '*';
      if (tag == 2)
        any_valued = 0;
!     if (string_length != 0) {
!       memcpy(filterp, string, string_length);
!       filterp += string_length;
!     }
!     *filterp = '\0';
      g_free(string);
    }
  
***************
*** 404,414 ****
    {
      (*filter_length)++;
      *filter = g_realloc(*filter, *filter_length);
!     strcat(*filter, "*");
    }
    
    /* NB: Allocated byte for this earlier */
!   strcat(*filter, ")");
  
    return ASN1_ERR_NOERROR;
  }
--- 432,444 ----
    {
      (*filter_length)++;
      *filter = g_realloc(*filter, *filter_length);
!     filterp = *filter + strlen(*filter);
!     *filterp++ = '*';
    }
    
    /* NB: Allocated byte for this earlier */
!   *filterp++ = ')';
!   *filterp = '\0';
  
    return ASN1_ERR_NOERROR;
  }
***************
*** 519,524 ****
--- 549,555 ----
       case LDAP_FILTER_PRESENT:
        {
          guchar *string;
+         char *filterp;
      
          if (con != ASN1_PRI)
            return ASN1_ERR_WRONG_TYPE;
***************
*** 527,533 ****
            return ret;
          *filter_length += 4 + length;
          *filter = g_realloc(*filter, *filter_length);
!         sprintf(*filter + strlen(*filter), "(%.*s=*)", (int)length, string);
          g_free(string);
        }
        break;
--- 558,573 ----
            return ret;
          *filter_length += 4 + length;
          *filter = g_realloc(*filter, *filter_length);
!         filterp = *filter + strlen(*filter);
!         *filterp++ = '(';
!         if (length != 0) {
!           memcpy(filterp, string, length);
!           filterp += length;
!         }
!         *filterp++ = '=';
!         *filterp++ = '*';
!         *filterp++ = ')';
!         *filterp = '\0';
          g_free(string);
        }
        break;