Re: [bug-mailutils] Re: How get_attachment_name from multiline Content-Disposition?

[Sergey Poznyakoff]

Sergey Poznyakoff <address@hidden> ha escrit:

> neither RFC 2045 nor 2183 seem to indicate that any whitespace
> characters are allowed around the '='.

After a bit of thought I decided it would do no harm to allow for it
anyway, so I've applied the attached patch. Please, pull.

Regards,
Sergey

>From 7287e840118d680efe1795e053500c999a950ade Mon Sep 17 00:00:00 2001
From: Sergey Poznyakoff <address@hidden>
Date: Thu, 8 Apr 2010 11:45:06 +0300
Subject: [PATCH] Improve MIME parameter parsing.

* mailbox/mimehdr.c (_header_get_param): Improve error checking.
Allow for optional whitespace around the '='.
* mailbox/rfc2047.c (mu_rfc2047_decode): tocode=NULL is OK.
---
 mailbox/mimehdr.c |   66 ++++++++++++++++++++++++++++++++++++++++-------------
 mailbox/rfc2047.c |    2 +-
 2 files changed, 51 insertions(+), 17 deletions(-)

diff --git a/mailbox/mimehdr.c b/mailbox/mimehdr.c
index 848842b..0c04c23 100644
--- a/mailbox/mimehdr.c
+++ b/mailbox/mimehdr.c
@@ -84,7 +84,11 @@
                    RFCs.
      ENOMEM      , if unable to allocate memory.
 */
-   
+
+/* Internal flag used by _header_get_param to delay increasing
+   estimated continuation index. */
+#define _MU_MIMEHDR_INCR_CIND 0x8000
+
 int
 _header_get_param (const char *field_body,
                   const char *disp,
@@ -117,7 +121,7 @@ _header_get_param (const char *field_body,
       
   while (p && *p)
     {
-      char *v, *e;
+      char *v, *e, *ep, *cp;
       size_t len, escaped_chars = 0;
       
       if (*p != ';')
@@ -128,9 +132,10 @@ _header_get_param (const char *field_body,
       
       /* walk upto start of param */      
       p = mu_str_skip_class (p + 1, MU_CTYPE_SPACE);
-      if ((v = strchr (p, '=')) == NULL)
+      if ((ep = strchr (p, '=')) == NULL)
        break;
-      v++;
+      /* Allow for optional whitespace after '=' */
+      v = mu_str_skip_class (ep + 1, MU_CTYPE_SPACE);
       /* Find end of the parameter */
       if (*v == '"')
        {
@@ -171,18 +176,15 @@ _header_get_param (const char *field_body,
          continue;
        }
 
-      res = 0; /* Indicate success */
-      
-      if (p[param_len] == '*')
+      cp = p + param_len;
+
+      if (*cp == '*')
        {
-         char *cp = p + param_len + 1;
-         
+         cp++;
          /* It is a parameter value continuation (RFC 2231, Section 3)
             or parameter value character set and language information
             (ibid., Section 4). */
-         if (*cp == '=')
-           flags |= MU_MIMEHDR_CSINFO;
-         else if (mu_isdigit (*cp))
+         if (mu_isdigit (*cp))
            {
              /* See if the index is OK */
          
@@ -194,16 +196,48 @@ _header_get_param (const char *field_body,
                  flags |= MU_MIMEHDR_CSINFO;
                  end++;
                }
-             if (*end != '=' || n != cind)
+             if (n != cind)
                {
                  res = MU_ERR_PARSE;
                  break;
                }
-             /* Everything OK, increase the estimation */
-             flags |= MU_MIMEHDR_MULTILINE;
-             cind++; 
+             /* Everything OK, mark this as a multiline (continued)
+                parameter. We also need to increment the estimation,
+                but it cannot be done right now because its value is
+                used below to decide whether to do flag cleanup
+                on error. So we set _MU_MIMEHDR_INCR_CIND flag instead
+                and increment cind later. */
+             flags |= (MU_MIMEHDR_MULTILINE|_MU_MIMEHDR_INCR_CIND);
+             /* And point cp to the last character: there are more
+                checks ahead. */
+             cp = end;
            }
+         else
+           flags |= MU_MIMEHDR_CSINFO;
        }
+      /* Allow for optional whitespace before '=' */
+      cp = mu_str_skip_class (cp, MU_CTYPE_SPACE);
+      /* cp must now point to the equals sign */
+      if (cp != ep)
+       {
+         /* Clean up everything, unless we're in the middle of a
+            parameter continuation. */
+         if (cind == 0)
+           flags = 0;
+
+         /* Try next parameter */
+         p = strchr (e, ';');
+         continue;
+       }
+
+      if (flags & _MU_MIMEHDR_INCR_CIND)
+       {
+         /* Increase the estimation. */
+         flags &= ~_MU_MIMEHDR_INCR_CIND;
+         cind++;
+       }
+      
+      res = 0; /* Indicate success */
       
       /* Prepare P for the next iteration */
       p = e;
diff --git a/mailbox/rfc2047.c b/mailbox/rfc2047.c
index bf23b7e..540f80e 100644
--- a/mailbox/rfc2047.c
+++ b/mailbox/rfc2047.c
@@ -92,7 +92,7 @@ mu_rfc2047_decode (const char *tocode, const char *input, 
char **ptostr)
      }                                           \
  } while (0) 
   
-  if (!tocode || !input)
+  if (!input)
     return EINVAL;
   if (!ptostr)
     return MU_ERR_OUT_PTR_NULL;
-- 
1.6.0.3