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4130 lines
100 KiB
4130 lines
100 KiB
/*
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* Copyright (C) 2002 Nigel Horne <njh@bandsman.co.uk>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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static char const rcsid[] = "$Id: mbox.c,v 1.277 2006/01/22 20:22:40 nigelhorne Exp $";
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#if HAVE_CONFIG_H
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#include "clamav-config.h"
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#endif
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#ifndef CL_DEBUG
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#define NDEBUG /* map CLAMAV debug onto standard */
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#endif
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#ifdef CL_THREAD_SAFE
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#ifndef _REENTRANT
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#define _REENTRANT /* for Solaris 2.8 */
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#endif
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#endif
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#include <stdio.h>
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#include <stdlib.h>
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#include <errno.h>
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#include <assert.h>
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#include <string.h>
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#include <strings.h>
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#include <ctype.h>
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#include <time.h>
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#include <fcntl.h>
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#include <sys/param.h>
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#include <clamav.h>
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#include <dirent.h>
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#include <limits.h>
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#if defined(HAVE_READDIR_R_3) || defined(HAVE_READDIR_R_2)
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#include <stddef.h>
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#endif
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#ifdef CL_THREAD_SAFE
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#include <pthread.h>
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#endif
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#include "table.h"
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#include "mbox.h"
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#include "blob.h"
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#include "line.h"
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#include "text.h"
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#include "message.h"
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#include "others.h"
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#include "defaults.h"
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#include "str.h"
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#include "filetypes.h"
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#include "uuencode.h"
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#ifdef CL_DEBUG
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#if __GLIBC__ == 2 && __GLIBC_MINOR__ >= 1
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#define HAVE_BACKTRACE
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#endif
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#endif
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#ifdef HAVE_BACKTRACE
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#include <execinfo.h>
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#include <signal.h>
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#include <syslog.h>
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static void sigsegv(int sig);
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static void print_trace(int use_syslog);
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#endif
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#if defined(NO_STRTOK_R) || !defined(CL_THREAD_SAFE)
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#undef strtok_r
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#undef __strtok_r
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#define strtok_r(a,b,c) strtok(a,b)
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#endif
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/* required for AIX and Tru64 */
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#ifdef TRUE
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#undef TRUE
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#endif
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#ifdef FALSE
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#undef FALSE
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#endif
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typedef enum { FALSE = 0, TRUE = 1 } bool;
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#ifndef isblank
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#define isblank(c) (((c) == ' ') || ((c) == '\t'))
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#endif
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#define SAVE_TO_DISC /* multipart/message are saved in a temporary file */
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/*
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* Code does exist to run FOLLORURLS on systems without libcurl, however that
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* is not recommended so it is not compiled by default
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*
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* On Solaris, when using the GNU C compiler, the clamAV build system uses the
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* Sun supplied ld instead of the GNU ld causing an error. Therefore you cannot
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* use WITH_CURL on Solaris with gcc, you must configure with
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* "--without-libcurl". I don't know if it works with Sun's own compiler
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*
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* Fails to link on Solaris 10 with this error:
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* Undefined first referenced
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* symbol in file
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* __floatdidf /opt/sfw/lib/libcurl.s
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*/
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#if C_SOLARIS && __GNUC__
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#undef WITH_CURL
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#endif
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#ifdef WITH_CURL
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#define FOLLOWURLS 5 /*
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* Maximum number of URLs scanned in a message
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* part. Helps to find Dialer.gen-45. If
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* not defined, don't check any URLs
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*/
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#endif
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#ifdef FOLLOWURLS
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#include "htmlnorm.h"
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#ifdef WITH_CURL /* Set in configure */
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/*
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* To build with WITH_CURL:
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* LDFLAGS=`curl-config --libs` ./configure ...
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*/
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#include <curl/curl.h>
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/*
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* Needs curl >= 7.11 (I've heard that 7.9 can cause crashes and I have seen
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* 7.10 segfault, later versions can be flakey as well)
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* untested)
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*/
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#if (LIBCURL_VERSION_NUM < 0x070B00)
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#undef WITH_CURL /* also undef FOLLOWURLS? */
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#endif
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#endif /*WITH_CURL*/
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#else /*!FOLLOWURLS*/
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#undef WITH_CURL
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#endif /*FOLLOWURLS*/
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/*
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* Define this to handle messages covered by section 7.3.2 of RFC1341.
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* This is experimental code so it is up to YOU to (1) ensure it's secure
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* (2) periodically trim the directory of old files
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*
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* If you use the load balancing feature of clamav-milter to run clamd on
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* more than one machine you must make sure that .../partial is on a shared
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* network filesystem
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*/
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#define PARTIAL_DIR
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/*#define NEW_WORLD*/
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static int cli_parse_mbox(const char *dir, int desc, unsigned int options);
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static message *parseEmailFile(FILE *fin, const table_t *rfc821Table, const char *firstLine, const char *dir);
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static message *parseEmailHeaders(const message *m, const table_t *rfc821Table);
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static int parseEmailHeader(message *m, const char *line, const table_t *rfc821Table);
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static int parseEmailBody(message *messageIn, text *textIn, const char *dir, const table_t *rfc821Table, const table_t *subtypeTable, unsigned int options);
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static int boundaryStart(const char *line, const char *boundary);
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static int endOfMessage(const char *line, const char *boundary);
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static int initialiseTables(table_t **rfc821Table, table_t **subtypeTable);
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static int getTextPart(message *const messages[], size_t size);
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static size_t strip(char *buf, int len);
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static bool continuationMarker(const char *line);
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static int parseMimeHeader(message *m, const char *cmd, const table_t *rfc821Table, const char *arg);
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static void saveTextPart(message *m, const char *dir);
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static char *rfc2047(const char *in);
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static char *rfc822comments(const char *in, char *out);
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#ifdef PARTIAL_DIR
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static int rfc1341(message *m, const char *dir);
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#endif
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static bool usefulHeader(int commandNumber, const char *cmd);
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static char *getline_from_mbox(char *buffer, size_t len, FILE *fin);
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static void checkURLs(message *m, const char *dir);
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#ifdef WITH_CURL
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struct arg {
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const char *url;
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const char *dir;
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char *filename;
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};
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#ifdef CL_THREAD_SAFE
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static void *getURL(void *a);
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#else
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static void *getURL(struct arg *arg);
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#endif
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#endif
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/* Maximum line length according to RFC821 */
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#define RFC2821LENGTH 1000
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/* Hashcodes for our hash tables */
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#define CONTENT_TYPE 1
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#define CONTENT_TRANSFER_ENCODING 2
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#define CONTENT_DISPOSITION 3
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/* Mime sub types */
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#define PLAIN 1
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#define ENRICHED 2
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#define HTML 3
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#define RICHTEXT 4
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#define MIXED 5
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#define ALTERNATIVE 6
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#define DIGEST 7
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#define SIGNED 8
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#define PARALLEL 9
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#define RELATED 10 /* RFC2387 */
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#define REPORT 11 /* RFC1892 */
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#define APPLEDOUBLE 12 /* Handling of this in only noddy for now */
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#define FAX MIXED /*
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* RFC3458
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* Drafts stated to treat is as mixed if it is
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* not known. This disappeared in the final
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* version (except when talking about
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* voice-message), but it is good enough for us
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* since we do no validation of coversheet
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* presence etc. (which also has disappeared
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* in the final version)
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*/
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#define ENCRYPTED 13 /*
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* e.g. RFC2015
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* Content-Type: multipart/encrypted;
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* boundary="nextPart1383049.XCRrrar2yq";
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* protocol="application/pgp-encrypted"
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*/
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#define X_BFILE RELATED /*
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* BeOS, expert two parts: the file and it's
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* attributes. The attributes part comes as
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* Content-Type: application/x-be_attribute
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* name="foo"
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* I can't find where it is defined, any
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* pointers would be appreciated. For now
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* we treat it as multipart/related
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*/
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#define KNOWBOT 14 /* Unknown and undocumented format? */
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static const struct tableinit {
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const char *key;
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int value;
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} rfc821headers[] = {
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/* TODO: make these regular expressions */
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{ "Content-Type", CONTENT_TYPE },
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{ "Content-Transfer-Encoding", CONTENT_TRANSFER_ENCODING },
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{ "Content-Disposition", CONTENT_DISPOSITION },
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{ NULL, 0 }
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}, mimeSubtypes[] = { /* see RFC2045 */
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/* subtypes of Text */
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{ "plain", PLAIN },
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{ "enriched", ENRICHED },
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{ "html", HTML },
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{ "richtext", RICHTEXT },
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/* subtypes of Multipart */
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{ "mixed", MIXED },
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{ "alternative", ALTERNATIVE },
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{ "digest", DIGEST },
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{ "signed", SIGNED },
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{ "parallel", PARALLEL },
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{ "related", RELATED },
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{ "report", REPORT },
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{ "appledouble", APPLEDOUBLE },
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{ "fax-message", FAX },
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{ "encrypted", ENCRYPTED },
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{ "x-bfile", X_BFILE }, /* BeOS */
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{ "knowbot", KNOWBOT }, /* ??? */
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{ "knowbot-metadata", KNOWBOT }, /* ??? */
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{ "knowbot-code", KNOWBOT }, /* ??? */
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{ "knowbot-state", KNOWBOT }, /* ??? */
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{ NULL, 0 }
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};
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#ifdef CL_THREAD_SAFE
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static pthread_mutex_t tables_mutex = PTHREAD_MUTEX_INITIALIZER;
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#endif
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#ifndef O_BINARY
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#define O_BINARY 0
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#endif
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#ifdef NEW_WORLD
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#undef PARTIAL_DIR
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#if HAVE_MMAP
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#if HAVE_SYS_MMAN_H
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#include <sys/mman.h>
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#else /* HAVE_SYS_MMAN_H */
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#undef HAVE_MMAP
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#endif
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#else /*HAVE_MMAP*/
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#undef NEW_WORLD
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#endif
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#endif
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#ifdef NEW_WORLD
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/*
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* Files larger than this are scanned with the old method, should be
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* StreamMaxLength, I guess
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* If NW_MAX_FILE_SIZE is not defined, all files go through the
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* new method. This definition is for machines very tight on RAM, or
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* with large StreamMaxLength values
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*/
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#define MAX_ALLOCATION 134217728 /* see libclamav/others.c */
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#define NW_MAX_FILE_SIZE MAX_ALLOCATION
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struct scanlist {
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const char *start;
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size_t size;
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encoding_type decoder; /* only BASE64 and QUOTEDPRINTABLE for now */
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struct scanlist *next;
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};
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static struct map {
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const char *offset; /* sorted */
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const char *word;
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struct map *next;
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} *map, *tail;
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static void create_map(const char *begin, const char *end);
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static void add_to_map(const char *offset, const char *word);
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static const char *find_in_map(const char *offset, const char *word);
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static void free_map(void);
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/*
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* This could be the future. Instead of parsing and decoding it just decodes.
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*
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* USE IT AT YOUR PERIL, a large number of viruses are not detected with this
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* method, possibly because the decoded files must be exact and not have
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* extra data at the start or end, which this code will produce.
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*
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* Currently only supports base64 and quoted-printable
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*
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* You may also see a lot of warnings. For the moment it falls back to old
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* world mode if it doesn't know what to do - that'll be removed.
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* The code is untidy...
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*
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* FIXME: Some mailbox scans are slower with this method. I suspect that it's
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* because the scan can proceed to the end of the file rather than the end
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* of the attachment which can mean than later emails are scanned many times
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*
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* FIXME: quoted printable doesn't know when to stop, so size related virus
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* matching breaks
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*
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* TODO: Fall through to cli_parse_mbox() too often
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*
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* TODO: Add support for systems without mmap()
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*
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* TODO: partial_dir fall through
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*/
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int
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cli_mbox(const char *dir, int desc, unsigned int options)
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{
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char *start, *ptr, *line;
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const char *last, *p, *q;
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size_t size;
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struct stat statb;
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message *m;
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fileblob *fb;
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int ret = 0;
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int wasAlloced;
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struct scanlist *scanlist, *scanelem;
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if(dir == NULL) {
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cli_warnmsg("cli_mbox called with NULL dir\n");
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return CL_ENULLARG;
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}
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if(fstat(desc, &statb) < 0)
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return CL_EOPEN;
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size = statb.st_size;
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if(size == 0)
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return CL_CLEAN;
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#ifdef NW_MAX_FILE_SIZE
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if(size > NW_MAX_FILE_SIZE)
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return cli_parse_mbox(dir, desc, options);
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#endif
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/*cli_warnmsg("NEW_WORLD is new code - use at your own risk.\n");*/
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#ifdef PARTIAL_DIR
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cli_warnmsg("PARTIAL_DIR doesn't work in the NEW_WORLD yet\n");
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#endif
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start = mmap(NULL, size, PROT_READ, MAP_PRIVATE, desc, 0);
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if(start == MAP_FAILED)
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return CL_EMEM;
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cli_dbgmsg("mmap'ed mbox\n");
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ptr = cli_malloc(size);
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if(ptr) {
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memcpy(ptr, start, size);
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munmap(start, size);
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start = ptr;
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wasAlloced = 1;
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} else
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wasAlloced = 0;
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/* last points to the last *valid* address in the array */
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last = &start[size - 1];
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create_map(start, last);
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scanelem = scanlist = NULL;
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q = start;
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/*
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* FIXME: mismatch of const char * and char * here and in later calls
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* to find_in_map()
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*/
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while((p = find_in_map(q, "base64")) != NULL) {
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cli_dbgmsg("Found base64\n");
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if(scanelem) {
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scanelem->next = cli_malloc(sizeof(struct scanlist));
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scanelem = scanelem->next;
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} else
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scanlist = scanelem = cli_malloc(sizeof(struct scanlist));
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scanelem->next = NULL;
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scanelem->decoder = BASE64;
|
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q = scanelem->start = &p[6];
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if(((p = find_in_map(q, "\nFrom ")) != NULL) ||
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((p = find_in_map(q, "base64")) != NULL) ||
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((p = find_in_map(q, "quoted-printable")) != NULL)) {
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scanelem->size = (size_t)(p - q);
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q = p;
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} else {
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scanelem->size = (size_t)(last - scanelem->start) + 1;
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break;
|
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}
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cli_dbgmsg("base64: last %u q %u\n", (unsigned int)last, (unsigned int)q);
|
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assert(scanelem->size <= size);
|
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}
|
|
|
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q = start;
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while((p = find_in_map(q, "quoted-printable")) != NULL) {
|
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if(p != q)
|
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switch(p[-1]) {
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case ' ':
|
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case ':':
|
|
case '=': /* wrong but allow it */
|
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break;
|
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default:
|
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q = &p[16];
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cli_dbgmsg("Ignore quoted-printable false positive\n");
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continue; /* false positive */
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}
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|
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cli_dbgmsg("Found quoted-printable\n");
|
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#ifdef notdef
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/*
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* The problem with quoted printable is recognising when to stop
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* parsing
|
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*/
|
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if(scanelem) {
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scanelem->next = cli_malloc(sizeof(struct scanlist));
|
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scanelem = scanelem->next;
|
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} else
|
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scanlist = scanelem = cli_malloc(sizeof(struct scanlist));
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scanelem->next = NULL;
|
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scanelem->decoder = QUOTEDPRINTABLE;
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q = scanelem->start = &p[16];
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cli_dbgmsg("qp: last %u q %u\n", (unsigned int)last, (unsigned int)q);
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if(((p = find_in_map(q, "\nFrom ")) != NULL) ||
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((p = find_in_map(q, "quoted-printable")) != NULL) ||
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((p = find_in_map(q, "base64")) != NULL)) {
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scanelem->size = (size_t)(p - q);
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q = p;
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cli_dbgmsg("qp: scanelem->size = %u\n", scanelem->size);
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} else {
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scanelem->size = (size_t)(last - scanelem->start) + 1;
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break;
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}
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assert(scanelem->size <= size);
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#else
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if(wasAlloced)
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free(start);
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else
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munmap(start, size);
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free_map();
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return cli_parse_mbox(dir, desc, options);
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#endif
|
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}
|
|
|
|
if(scanlist == NULL) {
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const struct tableinit *tableinit;
|
|
bool anyHeadersFound = FALSE;
|
|
bool hasuuencode = FALSE;
|
|
cli_file_t type;
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|
|
|
/* FIXME: message: There could of course be no decoder needed... */
|
|
for(tableinit = rfc821headers; tableinit->key; tableinit++)
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if(find_in_map(start, tableinit->key)) {
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anyHeadersFound = TRUE;
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break;
|
|
}
|
|
|
|
if((!anyHeadersFound) && find_in_map(start, "\nbegin "))
|
|
/* uuencoded part */
|
|
hasuuencode = TRUE;
|
|
|
|
free_map();
|
|
|
|
type = cli_filetype(start, size);
|
|
|
|
if((type == CL_TYPE_UNKNOWN_TEXT) &&
|
|
(strncmp(start, "Microsoft Mail Internet Headers", 31) == 0))
|
|
type = CL_TYPE_MAIL;
|
|
|
|
if(wasAlloced)
|
|
free(start);
|
|
else
|
|
munmap(start, size);
|
|
|
|
if(anyHeadersFound || hasuuencode) {
|
|
/* TODO: reduce the number of falls through here */
|
|
if(hasuuencode)
|
|
cli_dbgmsg("New world - fall back to old uudecoder, type %d\n", type);
|
|
else
|
|
cli_dbgmsg("cli_mbox: unknown encoder, type %d\n", type);
|
|
if(type == CL_TYPE_MAIL)
|
|
return cli_parse_mbox(dir, desc, options);
|
|
cli_dbgmsg("Unknown filetype %d, return CLEAN\n", type);
|
|
return CL_CLEAN;
|
|
}
|
|
|
|
/* The message could be a plain text phish */
|
|
if((type == CL_TYPE_MAIL) && (!(options&CL_DB_NOPHISHING)))
|
|
return cli_parse_mbox(dir, desc, options);
|
|
cli_dbgmsg("cli_mbox: I believe it's plain text which must be clean\n");
|
|
return CL_CLEAN;
|
|
}
|
|
free_map();
|
|
|
|
#if 0
|
|
if(wasAlloced) {
|
|
const char *max = NULL;
|
|
|
|
for(scanelem = scanlist; scanelem; scanelem = scanelem->next) {
|
|
const char *end = &scanelem->start[scanelem->size];
|
|
|
|
if(end > max)
|
|
max = end;
|
|
}
|
|
|
|
if(max < last)
|
|
printf("could free %d bytes\n", (int)(last - max));
|
|
}
|
|
#endif
|
|
|
|
for(scanelem = scanlist; scanelem; scanelem = scanelem->next) {
|
|
if(scanelem->decoder == BASE64) {
|
|
const char *b64start = scanelem->start;
|
|
size_t b64size = scanelem->size;
|
|
|
|
cli_dbgmsg("b64size = %lu\n", b64size);
|
|
while((*b64start != '\n') && (*b64start != '\r')) {
|
|
b64start++;
|
|
b64size--;
|
|
}
|
|
/*
|
|
* Look for the end of the headers
|
|
*/
|
|
while(b64start < last) {
|
|
if(*b64start == ';') {
|
|
b64start++;
|
|
b64size--;
|
|
} else if((memcmp(b64start, "\n\n", 2) == 0) ||
|
|
(memcmp(b64start, "\r\r", 2) == 0)) {
|
|
b64start += 2;
|
|
b64size -= 2;
|
|
break;
|
|
} else if(memcmp(b64start, "\r\n\r\n", 4) == 0) {
|
|
b64start += 4;
|
|
b64size -= 4;
|
|
break;
|
|
} else if(memcmp(b64start, "\n \n", 3) == 0) {
|
|
/*
|
|
* Some viruses are broken and have
|
|
* one space character at the end of
|
|
* the headers
|
|
*/
|
|
b64start += 3;
|
|
b64size -= 3;
|
|
break;
|
|
} else if(memcmp(b64start, "\r\n \r\n", 5) == 0) {
|
|
/*
|
|
* Some viruses are broken and have
|
|
* one space character at the end of
|
|
* the headers
|
|
*/
|
|
b64start += 5;
|
|
b64size -= 5;
|
|
break;
|
|
}
|
|
b64start++;
|
|
b64size--;
|
|
}
|
|
|
|
if(b64size > 0L)
|
|
while((!isalnum(*b64start)) && (*b64start != '/')) {
|
|
if(b64size-- == 0L)
|
|
break;
|
|
b64start++;
|
|
}
|
|
|
|
if(b64size > 0L) {
|
|
int lastline;
|
|
cli_dbgmsg("cli_mbox: decoding %ld base64 bytes\n", b64size);
|
|
|
|
line = NULL;
|
|
|
|
m = messageCreate();
|
|
if(m == NULL) {
|
|
if(wasAlloced)
|
|
free(start);
|
|
else
|
|
munmap(start, size);
|
|
|
|
return CL_EMEM;
|
|
}
|
|
messageSetEncoding(m, "base64");
|
|
|
|
lastline = 0;
|
|
|
|
do {
|
|
int length = 0;
|
|
char *newline, *equal;
|
|
|
|
/*printf("%ld: ", b64size); fflush(stdout);*/
|
|
|
|
for(ptr = b64start; b64size && (*ptr != '\n') && (*ptr != '\r'); ptr++) {
|
|
length++;
|
|
--b64size;
|
|
}
|
|
|
|
/*printf("%d: ", length); fflush(stdout);*/
|
|
|
|
newline = cli_realloc(line, length + 1);
|
|
if(newline == NULL)
|
|
break;
|
|
line = newline;
|
|
|
|
memcpy(line, b64start, length);
|
|
line[length] = '\0';
|
|
|
|
equal = strchr(line, '=');
|
|
if(equal) {
|
|
lastline++;
|
|
*equal = '\0';
|
|
}
|
|
/*puts(line);*/
|
|
|
|
if(messageAddStr(m, line) < 0)
|
|
break;
|
|
|
|
if((b64size > 0) && (*ptr == '\r')) {
|
|
b64start = ++ptr;
|
|
--b64size;
|
|
}
|
|
if((b64size > 0) && (*ptr == '\n')) {
|
|
b64start = ++ptr;
|
|
--b64size;
|
|
}
|
|
if(lastline)
|
|
break;
|
|
} while(b64size > 0L);
|
|
|
|
free(line);
|
|
fb = messageToFileblob(m, dir);
|
|
messageDestroy(m);
|
|
|
|
if(fb)
|
|
fileblobDestroy(fb);
|
|
else
|
|
ret = -1;
|
|
}
|
|
} else if(scanelem->decoder == QUOTEDPRINTABLE) {
|
|
const char *quotedstart = scanelem->start;
|
|
size_t quotedsize = scanelem->size;
|
|
|
|
cli_dbgmsg("quotedsize = %lu\n", quotedsize);
|
|
while(*quotedstart != '\n') {
|
|
quotedstart++;
|
|
quotedsize--;
|
|
}
|
|
/*
|
|
* Look for the end of the headers
|
|
*/
|
|
while(quotedstart < last) {
|
|
if(*quotedstart == ';') {
|
|
quotedstart++;
|
|
quotedsize--;
|
|
} else if((*quotedstart == '\n') || (*quotedstart == '\r')) {
|
|
quotedstart++;
|
|
quotedsize--;
|
|
if((*quotedstart == '\n') || (*quotedstart == '\r')) {
|
|
quotedstart++;
|
|
quotedsize--;
|
|
break;
|
|
}
|
|
}
|
|
quotedstart++;
|
|
quotedsize--;
|
|
}
|
|
|
|
while(!isalnum(*quotedstart)) {
|
|
quotedstart++;
|
|
quotedsize--;
|
|
}
|
|
|
|
if(quotedsize > 0L) {
|
|
cli_dbgmsg("cli_mbox: decoding %ld quoted-printable bytes\n", quotedsize);
|
|
|
|
m = messageCreate();
|
|
if(m == NULL) {
|
|
if(wasAlloced)
|
|
free(start);
|
|
else
|
|
munmap(start, size);
|
|
|
|
return CL_EMEM;
|
|
}
|
|
messageSetEncoding(m, "quoted-printable");
|
|
|
|
line = NULL;
|
|
|
|
do {
|
|
int length = 0;
|
|
char *newline;
|
|
|
|
/*printf("%ld: ", quotedsize); fflush(stdout);*/
|
|
|
|
for(ptr = quotedstart; quotedsize && (*ptr != '\n') && (*ptr != '\r'); ptr++) {
|
|
length++;
|
|
--quotedsize;
|
|
}
|
|
|
|
/*printf("%d: ", length); fflush(stdout);*/
|
|
|
|
newline = cli_realloc(line, length + 1);
|
|
if(newline == NULL)
|
|
break;
|
|
line = newline;
|
|
|
|
memcpy(line, quotedstart, length);
|
|
line[length] = '\0';
|
|
|
|
/*puts(line);*/
|
|
|
|
if(messageAddStr(m, line) < 0)
|
|
break;
|
|
|
|
if((quotedsize > 0) && (*ptr == '\r')) {
|
|
quotedstart = ++ptr;
|
|
--quotedsize;
|
|
}
|
|
if((quotedsize > 0) && (*ptr == '\n')) {
|
|
quotedstart = ++ptr;
|
|
--quotedsize;
|
|
}
|
|
} while(quotedsize > 0L);
|
|
|
|
free(line);
|
|
fb = messageToFileblob(m, dir);
|
|
messageDestroy(m);
|
|
|
|
if(fb)
|
|
fileblobDestroy(fb);
|
|
else
|
|
ret = -1;
|
|
}
|
|
}
|
|
}
|
|
scanelem = scanlist;
|
|
|
|
while(scanelem) {
|
|
struct scanlist *n = scanelem->next;
|
|
|
|
free(scanelem);
|
|
scanelem = n;
|
|
}
|
|
|
|
if(wasAlloced)
|
|
free(start);
|
|
else
|
|
munmap(start, size);
|
|
|
|
/*
|
|
* FIXME: Need to run cl_scandir() here and return that value
|
|
*/
|
|
if(ret == 0)
|
|
return CL_CLEAN; /* a lie - but it gets things going */
|
|
|
|
cli_dbgmsg("New world - don't know what to do - fall back to old world\n");
|
|
/* Fall back for now */
|
|
lseek(desc, 0L, SEEK_SET);
|
|
return cli_parse_mbox(dir, desc, options);
|
|
}
|
|
|
|
static void
|
|
create_map(const char *begin, const char *end)
|
|
{
|
|
const struct wordlist {
|
|
const char *word;
|
|
int len;
|
|
} wordlist[] = {
|
|
{ "base64", 6 },
|
|
{ "quoted-printable", 16 },
|
|
{ "\nbegin ", 7 },
|
|
{ "\nFrom ", 7 },
|
|
{ NULL, 0 }
|
|
};
|
|
|
|
if(map) {
|
|
cli_warnmsg("create_map called without free_map\n");
|
|
free_map();
|
|
}
|
|
while(begin < end) {
|
|
const struct wordlist *word;
|
|
|
|
for(word = wordlist; word->word; word++) {
|
|
if((end - begin) < word->len)
|
|
continue;
|
|
if(strncasecmp(begin, word->word, word->len) == 0) {
|
|
add_to_map(begin, word->word);
|
|
break;
|
|
}
|
|
}
|
|
begin++;
|
|
}
|
|
}
|
|
|
|
/* To sort map, assume 'offset' is presented in sorted order */
|
|
static void
|
|
add_to_map(const char *offset, const char *word)
|
|
{
|
|
if(map) {
|
|
tail->next = cli_malloc(sizeof(struct map)); /* FIXME: verify */
|
|
tail = tail->next;
|
|
} else
|
|
map = tail = cli_malloc(sizeof(struct map)); /* FIXME: verify */
|
|
|
|
tail->offset = offset;
|
|
tail->word = word;
|
|
tail->next = NULL;
|
|
}
|
|
|
|
static const char *
|
|
find_in_map(const char *offset, const char *word)
|
|
{
|
|
const struct map *item;
|
|
|
|
for(item = map; item; item = item->next)
|
|
if(item->offset >= offset)
|
|
if(strcasecmp(word, item->word) == 0)
|
|
return item->offset;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void
|
|
free_map(void)
|
|
{
|
|
while(map) {
|
|
struct map *next = map->next;
|
|
|
|
free(map);
|
|
map = next;
|
|
}
|
|
map = NULL;
|
|
}
|
|
|
|
#else /*!NEW_WORLD*/
|
|
int
|
|
cli_mbox(const char *dir, int desc, unsigned int options)
|
|
{
|
|
if(dir == NULL) {
|
|
cli_warnmsg("cli_mbox called with NULL dir\n");
|
|
return CL_ENULLARG;
|
|
}
|
|
return cli_parse_mbox(dir, desc, options);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* TODO: when signal handling is added, need to remove temp files when a
|
|
* signal is received
|
|
* TODO: add option to scan in memory not via temp files, perhaps with a
|
|
* named pipe or memory mapped file, though this won't work on big e-mails
|
|
* containing many levels of encapsulated messages - it'd just take too much
|
|
* RAM
|
|
* TODO: parse .msg format files
|
|
* TODO: fully handle AppleDouble format, see
|
|
* http://www.lazerware.com/formats/Specs/AppleSingle_AppleDouble.pdf
|
|
* TODO: ensure parseEmailHeaders is always called before parseEmailBody
|
|
* TODO: create parseEmail which calls parseEmailHeaders then parseEmailBody
|
|
* TODO: Look into TNEF. Is there anything that needs to be done here?
|
|
* TODO: Handle unepected NUL bytes in header lines which stop strcmp()s:
|
|
* e.g. \0Content-Type: application/binary;
|
|
*/
|
|
static int
|
|
cli_parse_mbox(const char *dir, int desc, unsigned int options)
|
|
{
|
|
int retcode, i;
|
|
message *body;
|
|
FILE *fd;
|
|
char buffer[RFC2821LENGTH + 1];
|
|
#ifdef HAVE_BACKTRACE
|
|
void (*segv)(int);
|
|
#endif
|
|
static table_t *rfc821, *subtype;
|
|
#ifdef CL_DEBUG
|
|
char tmpfilename[16];
|
|
int tmpfd;
|
|
#endif
|
|
|
|
#ifdef NEW_WORLD
|
|
cli_dbgmsg("fall back to old world\n");
|
|
#else
|
|
cli_dbgmsg("in mbox()\n");
|
|
#endif
|
|
|
|
i = dup(desc);
|
|
if((fd = fdopen(i, "rb")) == NULL) {
|
|
cli_errmsg("Can't open descriptor %d\n", desc);
|
|
close(i);
|
|
return CL_EOPEN;
|
|
}
|
|
#ifdef CL_DEBUG
|
|
/*
|
|
* Copy the incoming mail for debugging, so that if it falls over
|
|
* we have a copy of the offending email. This is debugging code
|
|
* that you shouldn't of course install in a live environment. I am
|
|
* not interested in hearing about security issues with this section
|
|
* of the parser.
|
|
*/
|
|
strcpy(tmpfilename, "/tmp/mboxXXXXXX");
|
|
tmpfd = mkstemp(tmpfilename);
|
|
if(tmpfd < 0) {
|
|
perror(tmpfilename);
|
|
cli_errmsg("Can't make debugging file\n");
|
|
} else {
|
|
FILE *tmpfp = fdopen(tmpfd, "w");
|
|
|
|
if(tmpfp) {
|
|
while(fgets(buffer, sizeof(buffer) - 1, fd) != NULL)
|
|
fputs(buffer, tmpfp);
|
|
fclose(tmpfp);
|
|
rewind(fd);
|
|
} else
|
|
cli_errmsg("Can't fdopen debugging file\n");
|
|
}
|
|
#endif
|
|
if(fgets(buffer, sizeof(buffer) - 1, fd) == NULL) {
|
|
/* empty message */
|
|
fclose(fd);
|
|
#ifdef CL_DEBUG
|
|
unlink(tmpfilename);
|
|
#endif
|
|
return CL_CLEAN;
|
|
}
|
|
#ifdef CL_THREAD_SAFE
|
|
pthread_mutex_lock(&tables_mutex);
|
|
#endif
|
|
if(rfc821 == NULL) {
|
|
assert(subtype == NULL);
|
|
|
|
if(initialiseTables(&rfc821, &subtype) < 0) {
|
|
rfc821 = NULL;
|
|
subtype = NULL;
|
|
#ifdef CL_THREAD_SAFE
|
|
pthread_mutex_unlock(&tables_mutex);
|
|
#endif
|
|
fclose(fd);
|
|
#ifdef CL_DEBUG
|
|
unlink(tmpfilename);
|
|
#endif
|
|
return CL_EMEM;
|
|
}
|
|
}
|
|
#ifdef CL_THREAD_SAFE
|
|
pthread_mutex_unlock(&tables_mutex);
|
|
#endif
|
|
|
|
#ifdef HAVE_BACKTRACE
|
|
segv = signal(SIGSEGV, sigsegv);
|
|
#endif
|
|
|
|
/*
|
|
* Is it a UNIX style mbox with more than one
|
|
* mail message, or just a single mail message?
|
|
*
|
|
* TODO: It would be better if we called cli_scandir here rather than
|
|
* in cli_scanmail. Then we could improve the way mailboxes with more
|
|
* than one message is handled, e.g. stopping parsing when an infected
|
|
* message is stopped, and giving a better indication of which message
|
|
* within the mailbox is infected
|
|
*/
|
|
if((strncmp(buffer, "From ", 5) == 0) && isalnum(buffer[5])) {
|
|
/*
|
|
* Have been asked to check a UNIX style mbox file, which
|
|
* may contain more than one e-mail message to decode
|
|
*
|
|
* It would be far better for scanners.c to do this splitting
|
|
* and do this
|
|
* FOR EACH mail in the mailbox
|
|
* DO
|
|
* pass this mail to cli_mbox --
|
|
* scan this file
|
|
* IF this file has a virus quit
|
|
* THEN
|
|
* return CL_VIRUS
|
|
* FI
|
|
* END
|
|
* This would remove a problem with this code that it can
|
|
* fill up the tmp directory before it starts scanning
|
|
*/
|
|
bool lastLineWasEmpty;
|
|
int messagenumber;
|
|
message *m = messageCreate();
|
|
|
|
if(m == NULL) {
|
|
fclose(fd);
|
|
#ifdef HAVE_BACKTRACE
|
|
signal(SIGSEGV, segv);
|
|
#endif
|
|
#ifdef CL_DEBUG
|
|
unlink(tmpfilename);
|
|
#endif
|
|
return CL_EMEM;
|
|
}
|
|
|
|
lastLineWasEmpty = FALSE;
|
|
messagenumber = 1;
|
|
|
|
do {
|
|
cli_chomp(buffer);
|
|
if(lastLineWasEmpty && (strncmp(buffer, "From ", 5) == 0) && isalnum(buffer[5])) {
|
|
cli_dbgmsg("Deal with email number %d\n", messagenumber++);
|
|
/*
|
|
* End of a message in the mail box
|
|
*/
|
|
body = parseEmailHeaders(m, rfc821);
|
|
if(body == NULL) {
|
|
messageReset(m);
|
|
continue;
|
|
}
|
|
messageDestroy(m);
|
|
if(messageGetBody(body))
|
|
if(!parseEmailBody(body, NULL, dir, rfc821, subtype, options)) {
|
|
messageReset(body);
|
|
m = body;
|
|
continue;
|
|
}
|
|
/*
|
|
* Starting a new message, throw away all the
|
|
* information about the old one. It would
|
|
* be best to be able to scan this message
|
|
* now, but cli_scanfile needs arguments
|
|
* that haven't been passed here so it can't be
|
|
* called
|
|
*/
|
|
m = body;
|
|
messageReset(body);
|
|
|
|
cli_dbgmsg("Finished processing message\n");
|
|
} else
|
|
lastLineWasEmpty = (bool)(buffer[0] == '\0');
|
|
|
|
if(isuuencodebegin(buffer)) {
|
|
/*
|
|
* Fast track visa to uudecode.
|
|
* TODO: binhex, yenc
|
|
*/
|
|
if(uudecodeFile(m, buffer, dir, fd) < 0)
|
|
if(messageAddStr(m, buffer) < 0)
|
|
break;
|
|
} else
|
|
if(messageAddStr(m, buffer) < 0)
|
|
break;
|
|
} while(fgets(buffer, sizeof(buffer) - 1, fd) != NULL);
|
|
|
|
fclose(fd);
|
|
|
|
cli_dbgmsg("Extract attachments from email %d\n", messagenumber);
|
|
body = parseEmailHeaders(m, rfc821);
|
|
messageDestroy(m);
|
|
} else {
|
|
/*
|
|
* It's a single message, parse the headers then the body
|
|
*/
|
|
if(strncmp(buffer, "P I ", 4) == 0)
|
|
/*
|
|
* CommuniGate Pro format: ignore headers until
|
|
* blank line
|
|
*/
|
|
while((fgets(buffer, sizeof(buffer) - 1, fd) != NULL) &&
|
|
(strchr("\r\n", buffer[0]) == NULL))
|
|
;
|
|
/*
|
|
* Ignore any blank lines at the top of the message
|
|
*/
|
|
while(strchr("\r\n", buffer[0]) &&
|
|
(getline_from_mbox(buffer, sizeof(buffer) - 1, fd) != NULL))
|
|
;
|
|
|
|
buffer[sizeof(buffer) - 1] = '\0';
|
|
|
|
body = parseEmailFile(fd, rfc821, buffer, dir);
|
|
fclose(fd);
|
|
}
|
|
|
|
/*
|
|
* This is not necessarily true, but since the only options are
|
|
* CL_CLEAN and CL_VIRUS this is the better choice. It would be
|
|
* nice to have CL_CONTINUESCANNING or something like that
|
|
*/
|
|
retcode = CL_CLEAN;
|
|
|
|
if(body) {
|
|
/*
|
|
* Write out the last entry in the mailbox
|
|
*/
|
|
if(messageGetBody(body))
|
|
if(!parseEmailBody(body, NULL, dir, rfc821, subtype, options))
|
|
retcode = CL_EFORMAT;
|
|
|
|
/*
|
|
* Tidy up and quit
|
|
*/
|
|
messageDestroy(body);
|
|
}
|
|
|
|
cli_dbgmsg("cli_mbox returning %d\n", retcode);
|
|
|
|
#ifdef HAVE_BACKTRACE
|
|
signal(SIGSEGV, segv);
|
|
#endif
|
|
|
|
#ifdef CL_DEBUG
|
|
unlink(tmpfilename);
|
|
#endif
|
|
return retcode;
|
|
}
|
|
|
|
/*
|
|
* Read in an email message from fin, parse it, and return the message
|
|
*
|
|
* FIXME: files full of new lines and nothing else are
|
|
* handled ungracefully...
|
|
*/
|
|
static message *
|
|
parseEmailFile(FILE *fin, const table_t *rfc821, const char *firstLine, const char *dir)
|
|
{
|
|
bool inHeader = TRUE;
|
|
bool contMarker = FALSE;
|
|
bool lastWasBlank = FALSE;
|
|
message *ret;
|
|
bool anyHeadersFound = FALSE;
|
|
int commandNumber = -1;
|
|
char *fullline = NULL, *boundary = NULL;
|
|
size_t fulllinelength = 0;
|
|
char buffer[RFC2821LENGTH + 1];
|
|
|
|
cli_dbgmsg("parseEmailFile\n");
|
|
|
|
ret = messageCreate();
|
|
if(ret == NULL)
|
|
return NULL;
|
|
|
|
strcpy(buffer, firstLine);
|
|
do {
|
|
char *line;
|
|
|
|
(void)cli_chomp(buffer);
|
|
|
|
line = buffer;
|
|
|
|
if(line[0] == '\0')
|
|
line = NULL;
|
|
|
|
/*
|
|
* Don't blank lines which are only spaces from headers,
|
|
* otherwise they'll be treated as the end of header marker
|
|
*/
|
|
if(lastWasBlank) {
|
|
lastWasBlank = FALSE;
|
|
if(boundaryStart(buffer, boundary)) {
|
|
cli_dbgmsg("Found a header line with space that should be blank\n");
|
|
inHeader = FALSE;
|
|
}
|
|
}
|
|
if(boundary) {
|
|
free(boundary);
|
|
boundary = NULL;
|
|
}
|
|
if(inHeader) {
|
|
cli_dbgmsg("parseEmailFile: check '%s' contMarker %d fullline %p\n",
|
|
buffer ? buffer : "", (int)contMarker, fullline);
|
|
if(line && isspace(line[0])) {
|
|
char copy[sizeof(buffer)];
|
|
|
|
strcpy(copy, buffer);
|
|
strstrip(copy);
|
|
if(copy[0] == '\0') {
|
|
/*
|
|
* The header line contains only white
|
|
* space. This is not the end of the
|
|
* headers according to RFC2822, but
|
|
* some MUAs will handle it as though
|
|
* it were, and virus writers exploit
|
|
* this bug. We can't just break from
|
|
* the loop here since that would allow
|
|
* other exploits such as inserting a
|
|
* white space line before the
|
|
* content-type line. So we just have
|
|
* to make a best guess. Sigh.
|
|
*/
|
|
if(fullline) {
|
|
if(parseEmailHeader(ret, fullline, rfc821) < 0)
|
|
continue;
|
|
|
|
free(fullline);
|
|
fullline = NULL;
|
|
}
|
|
if((boundary = (char *)messageFindArgument(ret, "boundary")) != NULL) {
|
|
lastWasBlank = TRUE;
|
|
continue;
|
|
}
|
|
}
|
|
}
|
|
lastWasBlank = FALSE;
|
|
if((line == NULL) && (fullline == NULL)) { /* empty line */
|
|
if(!contMarker) {
|
|
/*
|
|
* A blank line signifies the end of
|
|
* the header and the start of the text
|
|
*/
|
|
if(!anyHeadersFound)
|
|
/* Ignore the junk at the top */
|
|
continue;
|
|
|
|
cli_dbgmsg("End of header information\n");
|
|
inHeader = FALSE;
|
|
} else
|
|
contMarker = FALSE;
|
|
} else {
|
|
char *ptr;
|
|
const char *qptr;
|
|
int lookahead;
|
|
|
|
if(fullline == NULL) {
|
|
char cmd[RFC2821LENGTH + 1], out[RFC2821LENGTH + 1];
|
|
|
|
/*
|
|
* Continuation of line we're ignoring?
|
|
*/
|
|
if(isblank(line[0])) {
|
|
contMarker = continuationMarker(line);
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Is this a header we're interested in?
|
|
*/
|
|
if((strchr(line, ':') == NULL) ||
|
|
(cli_strtokbuf(line, 0, ":", cmd) == NULL)) {
|
|
if(strncmp(line, "From ", 5) == 0)
|
|
anyHeadersFound = TRUE;
|
|
continue;
|
|
}
|
|
|
|
ptr = rfc822comments(cmd, out);
|
|
commandNumber = tableFind(rfc821, ptr ? ptr : cmd);
|
|
|
|
switch(commandNumber) {
|
|
case CONTENT_TRANSFER_ENCODING:
|
|
case CONTENT_DISPOSITION:
|
|
case CONTENT_TYPE:
|
|
anyHeadersFound = TRUE;
|
|
break;
|
|
default:
|
|
if(!anyHeadersFound)
|
|
anyHeadersFound = usefulHeader(commandNumber, cmd);
|
|
continue;
|
|
}
|
|
fullline = strdup(line);
|
|
fulllinelength = strlen(line) + 1;
|
|
} else if(line != NULL) {
|
|
fulllinelength += strlen(line);
|
|
ptr = cli_realloc(fullline, fulllinelength);
|
|
if(ptr == NULL)
|
|
continue;
|
|
fullline = ptr;
|
|
strcat(fullline, line);
|
|
}
|
|
|
|
if(line) {
|
|
contMarker = continuationMarker(line);
|
|
|
|
if(contMarker)
|
|
continue;
|
|
} else
|
|
contMarker = FALSE;
|
|
|
|
assert(fullline != NULL);
|
|
|
|
lookahead = getc(fin);
|
|
if(lookahead != EOF) {
|
|
ungetc(lookahead, fin);
|
|
|
|
/*
|
|
* Section B.2 of RFC822 says TAB or
|
|
* SPACE means a continuation of the
|
|
* previous entry.
|
|
*
|
|
* Add all the arguments on the line
|
|
*/
|
|
if(isblank(lookahead))
|
|
continue;
|
|
}
|
|
|
|
if(line) {
|
|
int quotes = 0;
|
|
for(qptr = fullline; *qptr; qptr++)
|
|
if(*qptr == '\"')
|
|
quotes++;
|
|
|
|
if(quotes & 1)
|
|
continue;
|
|
}
|
|
|
|
ptr = rfc822comments(fullline, NULL);
|
|
if(ptr) {
|
|
free(fullline);
|
|
fullline = ptr;
|
|
}
|
|
|
|
if(parseEmailHeader(ret, fullline, rfc821) < 0)
|
|
continue;
|
|
|
|
free(fullline);
|
|
fullline = NULL;
|
|
}
|
|
} else if(line && isuuencodebegin(line)) {
|
|
/*
|
|
* Fast track visa to uudecode.
|
|
* TODO: binhex, yenc
|
|
*/
|
|
if(uudecodeFile(ret, line, dir, fin) < 0)
|
|
if(messageAddStr(ret, line) < 0)
|
|
break;
|
|
} else
|
|
if(messageAddStr(ret, line) < 0)
|
|
break;
|
|
} while(getline_from_mbox(buffer, sizeof(buffer) - 1, fin) != NULL);
|
|
|
|
if(fullline) {
|
|
if(*fullline) switch(commandNumber) {
|
|
case CONTENT_TRANSFER_ENCODING:
|
|
case CONTENT_DISPOSITION:
|
|
case CONTENT_TYPE:
|
|
cli_dbgmsg("parseEmailHeaders: Fullline unparsed '%s'\n", fullline);
|
|
}
|
|
free(fullline);
|
|
}
|
|
|
|
if(!anyHeadersFound) {
|
|
/*
|
|
* False positive in believing we have an e-mail when we don't
|
|
*/
|
|
messageDestroy(ret);
|
|
cli_dbgmsg("parseEmailFile: no headers found, assuming it isn't an email\n");
|
|
return NULL;
|
|
}
|
|
|
|
messageClean(ret);
|
|
|
|
cli_dbgmsg("parseEmailFile: return\n");
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* The given message contains a raw e-mail.
|
|
*
|
|
* Returns the message's body with the correct arguments set
|
|
*
|
|
* The downside of this approach is that for a short time we have two copies
|
|
* of the message in memory, the upside is that it makes for easier parsing
|
|
* of encapsulated messages, and in the long run uses less memory in those
|
|
* scenarios
|
|
*
|
|
* TODO: remove the duplication with parseEmailFile
|
|
*/
|
|
static message *
|
|
parseEmailHeaders(const message *m, const table_t *rfc821)
|
|
{
|
|
bool inHeader = TRUE;
|
|
const text *t;
|
|
message *ret;
|
|
bool anyHeadersFound = FALSE;
|
|
int commandNumber = -1;
|
|
char *fullline = NULL;
|
|
size_t fulllinelength = 0;
|
|
|
|
cli_dbgmsg("parseEmailHeaders\n");
|
|
|
|
if(m == NULL)
|
|
return NULL;
|
|
|
|
ret = messageCreate();
|
|
|
|
for(t = messageGetBody(m); t; t = t->t_next) {
|
|
const char *buffer;
|
|
|
|
if(t->t_line)
|
|
buffer = lineGetData(t->t_line);
|
|
else
|
|
buffer = NULL;
|
|
|
|
if(inHeader) {
|
|
cli_dbgmsg("parseEmailHeaders: check '%s'\n",
|
|
buffer ? buffer : "");
|
|
if(buffer == NULL) {
|
|
/*
|
|
* A blank line signifies the end of
|
|
* the header and the start of the text
|
|
*/
|
|
cli_dbgmsg("End of header information\n");
|
|
inHeader = FALSE;
|
|
if(!anyHeadersFound) {
|
|
cli_dbgmsg("Nothing interesting in the header\n");
|
|
break;
|
|
}
|
|
} else {
|
|
char *ptr;
|
|
const char *qptr;
|
|
int quotes;
|
|
|
|
if(fullline == NULL) {
|
|
char cmd[RFC2821LENGTH + 1];
|
|
|
|
/*
|
|
* Continuation of line we're ignoring?
|
|
*/
|
|
if(isblank(buffer[0]))
|
|
continue;
|
|
|
|
/*
|
|
* Is this a header we're interested in?
|
|
*/
|
|
if((strchr(buffer, ':') == NULL) ||
|
|
(cli_strtokbuf(buffer, 0, ":", cmd) == NULL)) {
|
|
if(strncmp(buffer, "From ", 5) == 0)
|
|
anyHeadersFound = TRUE;
|
|
continue;
|
|
}
|
|
|
|
ptr = rfc822comments(cmd, NULL);
|
|
commandNumber = tableFind(rfc821, ptr ? ptr : cmd);
|
|
if(ptr)
|
|
free(ptr);
|
|
|
|
switch(commandNumber) {
|
|
case CONTENT_TRANSFER_ENCODING:
|
|
case CONTENT_DISPOSITION:
|
|
case CONTENT_TYPE:
|
|
anyHeadersFound = TRUE;
|
|
break;
|
|
default:
|
|
if(!anyHeadersFound)
|
|
anyHeadersFound = usefulHeader(commandNumber, cmd);
|
|
continue;
|
|
}
|
|
fullline = strdup(buffer);
|
|
fulllinelength = strlen(buffer) + 1;
|
|
} else if(buffer) {
|
|
fulllinelength += strlen(buffer);
|
|
ptr = cli_realloc(fullline, fulllinelength);
|
|
if(ptr == NULL)
|
|
continue;
|
|
fullline = ptr;
|
|
strcat(fullline, buffer);
|
|
}
|
|
|
|
assert(fullline != NULL);
|
|
|
|
if(t->t_next && (t->t_next->t_line != NULL))
|
|
/*
|
|
* Section B.2 of RFC822 says TAB or
|
|
* SPACE means a continuation of the
|
|
* previous entry.
|
|
*
|
|
* Add all the arguments on the line
|
|
*/
|
|
if(isblank(lineGetData(t->t_next->t_line)[0]))
|
|
continue;
|
|
|
|
quotes = 0;
|
|
for(qptr = fullline; *qptr; qptr++)
|
|
if(*qptr == '\"')
|
|
quotes++;
|
|
|
|
if(quotes & 1)
|
|
continue;
|
|
|
|
ptr = rfc822comments(fullline, NULL);
|
|
if(ptr) {
|
|
free(fullline);
|
|
fullline = ptr;
|
|
}
|
|
|
|
if(parseEmailHeader(ret, fullline, rfc821) < 0)
|
|
continue;
|
|
|
|
free(fullline);
|
|
fullline = NULL;
|
|
}
|
|
} else
|
|
/*cli_dbgmsg("Add line to body '%s'\n", buffer);*/
|
|
if(messageAddLine(ret, t->t_line) < 0)
|
|
break;
|
|
}
|
|
|
|
if(fullline) {
|
|
if(*fullline) switch(commandNumber) {
|
|
case CONTENT_TRANSFER_ENCODING:
|
|
case CONTENT_DISPOSITION:
|
|
case CONTENT_TYPE:
|
|
cli_dbgmsg("parseEmailHeaders: Fullline unparsed '%s'\n", fullline);
|
|
}
|
|
free(fullline);
|
|
}
|
|
|
|
if(!anyHeadersFound) {
|
|
/*
|
|
* False positive in believing we have an e-mail when we don't
|
|
*/
|
|
messageDestroy(ret);
|
|
cli_dbgmsg("parseEmailHeaders: no headers found, assuming it isn't an email\n");
|
|
return NULL;
|
|
}
|
|
|
|
messageClean(ret);
|
|
|
|
cli_dbgmsg("parseEmailHeaders: return\n");
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Handle a header line of an email message
|
|
*/
|
|
static int
|
|
parseEmailHeader(message *m, const char *line, const table_t *rfc821)
|
|
{
|
|
char *cmd;
|
|
int ret = -1;
|
|
#ifdef CL_THREAD_SAFE
|
|
char *strptr;
|
|
#endif
|
|
const char *separater;
|
|
char *copy, tokenseparater[2];
|
|
|
|
cli_dbgmsg("parseEmailHeader '%s'\n", line);
|
|
|
|
/*
|
|
* In RFC822 the separater between the key a value is a colon,
|
|
* e.g. Content-Transfer-Encoding: base64
|
|
* However some MUA's are lapse about this and virus writers exploit
|
|
* this hole, so we need to check all known possiblities
|
|
*/
|
|
for(separater = ":= "; *separater; separater++)
|
|
if(strchr(line, *separater) != NULL)
|
|
break;
|
|
|
|
if(*separater == '\0')
|
|
return -1;
|
|
|
|
copy = rfc2047(line);
|
|
if(copy == NULL)
|
|
/* an RFC checker would return -1 here */
|
|
copy = strdup(line);
|
|
|
|
tokenseparater[0] = *separater;
|
|
tokenseparater[1] = '\0';
|
|
|
|
#ifdef CL_THREAD_SAFE
|
|
cmd = strtok_r(copy, tokenseparater, &strptr);
|
|
#else
|
|
cmd = strtok(copy, tokenseparater);
|
|
#endif
|
|
|
|
if(cmd && (strstrip(cmd) > 0)) {
|
|
#ifdef CL_THREAD_SAFE
|
|
char *arg = strtok_r(NULL, "", &strptr);
|
|
#else
|
|
char *arg = strtok(NULL, "");
|
|
#endif
|
|
|
|
if(arg)
|
|
/*
|
|
* Found a header such as
|
|
* Content-Type: multipart/mixed;
|
|
* set arg to be
|
|
* "multipart/mixed" and cmd to
|
|
* be "Content-Type"
|
|
*/
|
|
ret = parseMimeHeader(m, cmd, rfc821, arg);
|
|
}
|
|
free(copy);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* This is a recursive routine.
|
|
* FIXME: We are not passed &mrec so we can't check against MAX_MAIL_RECURSION
|
|
*
|
|
* This function parses the body of mainMessage and saves its attachments in dir
|
|
*
|
|
* mainMessage is the buffer to be parsed, it contains an e-mail's body, without
|
|
* any headers. First time of calling it'll be
|
|
* the whole message. Later it'll be parts of a multipart message
|
|
* textIn is the plain text message being built up so far
|
|
*
|
|
* Returns:
|
|
* 0 for fail
|
|
* 1 for success, attachments saved
|
|
* 2 for success, attachments not saved
|
|
*/
|
|
static int /* success or fail */
|
|
parseEmailBody(message *messageIn, text *textIn, const char *dir, const table_t *rfc821Table, const table_t *subtypeTable, unsigned int options)
|
|
{
|
|
message **messages; /* parts of a multipart message */
|
|
int inMimeHead, i, rc = 1, htmltextPart, multiparts = 0;
|
|
text *aText;
|
|
const char *cptr;
|
|
message *mainMessage;
|
|
fileblob *fb;
|
|
|
|
cli_dbgmsg("in parseEmailBody\n");
|
|
|
|
aText = textIn;
|
|
messages = NULL;
|
|
mainMessage = messageIn;
|
|
|
|
/* Anything left to be parsed? */
|
|
if(mainMessage && (messageGetBody(mainMessage) != NULL)) {
|
|
mime_type mimeType;
|
|
int subtype, inhead;
|
|
const char *mimeSubtype, *boundary;
|
|
char *protocol;
|
|
const text *t_line;
|
|
/*bool isAlternative;*/
|
|
message *aMessage;
|
|
|
|
cli_dbgmsg("Parsing mail file\n");
|
|
|
|
mimeType = messageGetMimeType(mainMessage);
|
|
mimeSubtype = messageGetMimeSubtype(mainMessage);
|
|
|
|
/* pre-process */
|
|
subtype = tableFind(subtypeTable, mimeSubtype);
|
|
if((mimeType == TEXT) && (subtype == PLAIN)) {
|
|
/*
|
|
* This is effectively no encoding, notice that we
|
|
* don't check that charset is us-ascii
|
|
*/
|
|
cli_dbgmsg("assume no encoding\n");
|
|
mimeType = NOMIME;
|
|
messageSetMimeSubtype(mainMessage, "");
|
|
} else if((mimeType == MESSAGE) &&
|
|
(strcasecmp(mimeSubtype, "rfc822-headers") == 0)) {
|
|
/*
|
|
* RFC1892/RFC3462: section 2 text/rfc822-headers
|
|
* incorrectly sent as message/rfc822-headers
|
|
*
|
|
* Parse as text/plain, i.e. no mime
|
|
*/
|
|
cli_dbgmsg("Changing message/rfc822-headers to text/rfc822-headers\n");
|
|
mimeType = NOMIME;
|
|
messageSetMimeSubtype(mainMessage, "");
|
|
}
|
|
|
|
cli_dbgmsg("mimeType = %d\n", mimeType);
|
|
|
|
switch(mimeType) {
|
|
case NOMIME:
|
|
cli_dbgmsg("Not a mime encoded message\n");
|
|
aText = textAddMessage(aText, mainMessage);
|
|
break;
|
|
case TEXT:
|
|
/* text/plain has been preprocessed as no encoding */
|
|
if((options&CL_SCAN_MAILURL) && (subtype == HTML))
|
|
checkURLs(mainMessage, dir);
|
|
break;
|
|
case MULTIPART:
|
|
cli_dbgmsg("Content-type 'multipart' handler\n");
|
|
boundary = messageFindArgument(mainMessage, "boundary");
|
|
|
|
if(boundary == NULL) {
|
|
cli_warnmsg("Multipart MIME message contains no boundaries\n");
|
|
/* Broken e-mail message */
|
|
mimeType = NOMIME;
|
|
/*
|
|
* The break means that we will still
|
|
* check if the file contains a uuencoded file
|
|
*/
|
|
break;
|
|
}
|
|
|
|
/* Perhaps it should assume mixed? */
|
|
if(mimeSubtype[0] == '\0') {
|
|
cli_warnmsg("Multipart has no subtype assuming alternative\n");
|
|
mimeSubtype = "alternative";
|
|
messageSetMimeSubtype(mainMessage, "alternative");
|
|
}
|
|
|
|
/*
|
|
* Get to the start of the first message
|
|
*/
|
|
t_line = messageGetBody(mainMessage);
|
|
|
|
if(t_line == NULL) {
|
|
cli_warnmsg("Multipart MIME message has no body\n");
|
|
free((char *)boundary);
|
|
mimeType = NOMIME;
|
|
break;
|
|
}
|
|
|
|
do
|
|
if(t_line->t_line) {
|
|
if(boundaryStart(lineGetData(t_line->t_line), boundary))
|
|
break;
|
|
/*
|
|
* Found a binhex file before
|
|
* the first multipart
|
|
* TODO: check yEnc
|
|
*/
|
|
if(binhexBegin(mainMessage) == t_line) {
|
|
if(messageGetEncoding(mainMessage) == NOENCODING) {
|
|
messageSetEncoding(mainMessage, "x-binhex");
|
|
fb = messageToFileblob(mainMessage, dir);
|
|
|
|
if(fb)
|
|
fileblobDestroy(fb);
|
|
}
|
|
} else if(encodingLine(mainMessage) == t_line->t_next) {
|
|
/*
|
|
* We look for the next line
|
|
* since later on we'll skip
|
|
* over the important line when
|
|
* we think it's a blank line
|
|
* at the top of the message -
|
|
* which it would have been in
|
|
* an RFC compliant world
|
|
*/
|
|
cli_dbgmsg("Found MIME attachment before the first MIME section\n");
|
|
if(messageGetEncoding(mainMessage) == NOENCODING)
|
|
break;
|
|
}
|
|
}
|
|
while((t_line = t_line->t_next) != NULL);
|
|
|
|
if(t_line == NULL) {
|
|
cli_dbgmsg("Multipart MIME message contains no boundary lines\n");
|
|
/*
|
|
* Free added by Thomas Lamy
|
|
* <Thomas.Lamy@in-online.net>
|
|
*/
|
|
free((char *)boundary);
|
|
mimeType = NOMIME;
|
|
/*
|
|
* The break means that we will still
|
|
* check if the file contains a yEnc/binhex file
|
|
*/
|
|
break;
|
|
}
|
|
/*
|
|
* Build up a table of all of the parts of this
|
|
* multipart message. Remember, each part may itself
|
|
* be a multipart message.
|
|
*/
|
|
inhead = 1;
|
|
inMimeHead = 0;
|
|
|
|
/*
|
|
* Parse the mainMessage object and create an array
|
|
* of objects called messages, one for each of the
|
|
* multiparts that mainMessage contains
|
|
*
|
|
* This looks like parseEmailHeaders() - maybe there's
|
|
* some duplication of code to be cleaned up
|
|
*/
|
|
for(multiparts = 0; t_line; multiparts++) {
|
|
int lines = 0;
|
|
message **m;
|
|
|
|
m = cli_realloc(messages, ((multiparts + 1) * sizeof(message *)));
|
|
if(m == NULL)
|
|
break;
|
|
messages = m;
|
|
|
|
aMessage = messages[multiparts] = messageCreate();
|
|
if(aMessage == NULL) {
|
|
multiparts--;
|
|
continue;
|
|
}
|
|
|
|
cli_dbgmsg("Now read in part %d\n", multiparts);
|
|
|
|
/*
|
|
* Ignore blank lines. There shouldn't be ANY
|
|
* but some viruses insert them
|
|
*/
|
|
while((t_line = t_line->t_next) != NULL)
|
|
if(t_line->t_line &&
|
|
/*(cli_chomp(t_line->t_text) > 0))*/
|
|
(strlen(lineGetData(t_line->t_line)) > 0))
|
|
break;
|
|
|
|
if(t_line == NULL) {
|
|
cli_dbgmsg("Empty part\n");
|
|
/*
|
|
* Remove this part unless there's
|
|
* a binhex portion somewhere in
|
|
* the complete message that we may
|
|
* throw away by mistake if the MIME
|
|
* encoding information is incorrect
|
|
*/
|
|
if(binhexBegin(mainMessage) == NULL) {
|
|
messageDestroy(aMessage);
|
|
--multiparts;
|
|
}
|
|
continue;
|
|
}
|
|
|
|
do {
|
|
const char *line = lineGetData(t_line->t_line);
|
|
|
|
/*cli_dbgmsg("multipart %d: inMimeHead %d inhead %d boundary '%s' line '%s' next '%s'\n",
|
|
multiparts, inMimeHead, inhead, boundary, line,
|
|
t_line->t_next && t_line->t_next->t_line ? lineGetData(t_line->t_next->t_line) : "(null)");*/
|
|
|
|
if(inMimeHead) { /* continuation line */
|
|
if(line == NULL) {
|
|
/*inhead =*/ inMimeHead = 0;
|
|
continue;
|
|
}
|
|
/*
|
|
* Handle continuation lines
|
|
* because the previous line
|
|
* ended with a ; or this line
|
|
* starts with a white space
|
|
*/
|
|
cli_dbgmsg("Multipart %d: About to add mime Argument '%s'\n",
|
|
multiparts, line);
|
|
/*
|
|
* Handle the case when it
|
|
* isn't really a continuation
|
|
* line:
|
|
* Content-Type: application/octet-stream;
|
|
* Content-Transfer-Encoding: base64
|
|
*/
|
|
parseEmailHeader(aMessage, line, rfc821Table);
|
|
|
|
while(isspace((int)*line))
|
|
line++;
|
|
|
|
if(*line == '\0') {
|
|
inhead = inMimeHead = 0;
|
|
continue;
|
|
}
|
|
/*
|
|
* This may cause a trailing ';'
|
|
* to be added if this test
|
|
* fails - TODO: verify this
|
|
*/
|
|
inMimeHead = continuationMarker(line);
|
|
messageAddArgument(aMessage, line);
|
|
} else if(inhead) { /* handling normal headers */
|
|
int quotes;
|
|
char *fullline, *ptr;
|
|
const char *qptr;
|
|
const text *next;
|
|
|
|
if(line == NULL) {
|
|
/*
|
|
* empty line, should the end of the headers,
|
|
* but some base64 decoders, e.g. uudeview, are broken
|
|
* and will handle this type of entry, decoding the
|
|
* base64 content...
|
|
* Content-Type: application/octet-stream; name=text.zip
|
|
* Content-Transfer-Encoding: base64
|
|
* Content-Disposition: attachment; filename="text.zip"
|
|
*
|
|
* Content-Disposition: attachment;
|
|
* filename=text.zip
|
|
* Content-Type: application/octet-stream;
|
|
* name=text.zip
|
|
* Content-Transfer-Encoding: base64
|
|
*
|
|
* UEsDBAoAAAAAAACgPjJ2RHw676gAAO+oAABEAAAAbWFpbF90ZXh0LWluZm8udHh0ICAgICAgICAg
|
|
*/
|
|
next = t_line->t_next;
|
|
if(next && next->t_line) {
|
|
const char *data = lineGetData(next->t_line);
|
|
|
|
if((messageGetEncoding(aMessage) == NOENCODING) &&
|
|
(messageGetMimeType(aMessage) == APPLICATION))
|
|
/*
|
|
* Handle this nightmare (note the blank
|
|
* line in the header and the incorrect
|
|
* content-transfer-encoding header)
|
|
*
|
|
* Content-Type: application/octet-stream; name="zipped_files.EXEX-Spanska: Yes
|
|
*
|
|
* r-Encoding: base64
|
|
* Content-Disposition: attachment; filename="zipped_files.EXE"
|
|
*/
|
|
if(strstr(data, "base64")) {
|
|
messageSetEncoding(aMessage, "base64");
|
|
cli_dbgmsg("Ignoring fake end of headers\n");
|
|
continue;
|
|
}
|
|
if((strncmp(data, "Content", 7) == 0) ||
|
|
(strncmp(data, "filename=", 9) == 0)) {
|
|
cli_dbgmsg("Ignoring fake end of headers\n");
|
|
continue;
|
|
}
|
|
}
|
|
cli_dbgmsg("Multipart %d: End of header information\n",
|
|
multiparts);
|
|
inhead = 0;
|
|
continue;
|
|
}
|
|
if(isspace((int)*line)) {
|
|
/*
|
|
* The first line is
|
|
* continuation line.
|
|
* This is tricky
|
|
* to handle, but
|
|
* all we can do is our
|
|
* best
|
|
*/
|
|
cli_dbgmsg("Part %d starts with a continuation line\n",
|
|
multiparts);
|
|
messageAddArgument(aMessage, line);
|
|
/*
|
|
* Give it a default
|
|
* MIME type since
|
|
* that may be the
|
|
* missing line
|
|
*
|
|
* Choose application to
|
|
* force a save
|
|
*/
|
|
if(messageGetMimeType(aMessage) == NOMIME)
|
|
messageSetMimeType(aMessage, "application");
|
|
continue;
|
|
}
|
|
|
|
inMimeHead = FALSE;
|
|
|
|
assert(strlen(line) <= RFC2821LENGTH);
|
|
|
|
fullline = rfc822comments(line, NULL);
|
|
if(fullline == NULL)
|
|
fullline = strdup(line);
|
|
|
|
quotes = 0;
|
|
for(qptr = fullline; *qptr; qptr++)
|
|
if(*qptr == '\"')
|
|
quotes++;
|
|
|
|
/*
|
|
* Fold next lines to the end of this
|
|
* if they start with a white space
|
|
* or if this line has an odd number of quotes:
|
|
* Content-Type: application/octet-stream; name="foo
|
|
* "
|
|
*/
|
|
next = t_line->t_next;
|
|
while(next && next->t_line) {
|
|
const char *data = lineGetData(next->t_line);
|
|
|
|
/*if((!isspace(data[0])) &&
|
|
((quotes & 1) == 0))
|
|
break;*/
|
|
if(!isspace(data[0]))
|
|
break;
|
|
|
|
if(data[1] == '\0') {
|
|
/*
|
|
* Broken message: the
|
|
* blank line at the end
|
|
* of the headers isn't blank -
|
|
* it contains a space
|
|
*/
|
|
cli_dbgmsg("Multipart %d: headers not terminated by blank line\n",
|
|
multiparts);
|
|
inhead = FALSE;
|
|
break;
|
|
}
|
|
|
|
ptr = cli_realloc(fullline,
|
|
strlen(fullline) + strlen(data) + 1);
|
|
|
|
if(ptr == NULL)
|
|
break;
|
|
|
|
fullline = ptr;
|
|
strcat(fullline, data);
|
|
|
|
/*for(qptr = data; *qptr; qptr++)
|
|
if(*qptr == '\"')
|
|
quotes++;*/
|
|
|
|
t_line = next;
|
|
next = next->t_next;
|
|
}
|
|
cli_dbgmsg("Multipart %d: About to parse folded header '%s'\n",
|
|
multiparts, fullline);
|
|
|
|
parseEmailHeader(aMessage, fullline, rfc821Table);
|
|
free(fullline);
|
|
} else if(endOfMessage(line, boundary)) {
|
|
/*
|
|
* Some viruses put information
|
|
* *after* the end of message,
|
|
* which presumably some broken
|
|
* mail clients find, so we
|
|
* can't assume that this
|
|
* is the end of the message
|
|
*/
|
|
/* t_line = NULL;*/
|
|
break;
|
|
} else if(boundaryStart(line, boundary)) {
|
|
inhead = 1;
|
|
break;
|
|
} else {
|
|
if(messageAddLine(aMessage, t_line->t_line) < 0)
|
|
break;
|
|
lines++;
|
|
}
|
|
} while((t_line = t_line->t_next) != NULL);
|
|
|
|
messageClean(aMessage);
|
|
|
|
cli_dbgmsg("Part %d has %d lines\n",
|
|
multiparts, lines);
|
|
}
|
|
|
|
free((char *)boundary);
|
|
|
|
/*
|
|
* Preprocess. Anything special to be done before
|
|
* we handle the multiparts?
|
|
*/
|
|
switch(tableFind(subtypeTable, mimeSubtype)) {
|
|
case KNOWBOT:
|
|
/* TODO */
|
|
cli_dbgmsg("multipart/knowbot parsed as multipart/mixed for now\n");
|
|
mimeSubtype = "mixed";
|
|
break;
|
|
case -1:
|
|
/*
|
|
* According to section 7.2.6 of
|
|
* RFC1521, unrecognised multiparts
|
|
* should be treated as multipart/mixed.
|
|
*/
|
|
cli_dbgmsg("Unsupported multipart format `%s', parsed as mixed\n", mimeSubtype);
|
|
mimeSubtype = "mixed";
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* We've finished message we're parsing
|
|
*/
|
|
if(mainMessage && (mainMessage != messageIn)) {
|
|
messageDestroy(mainMessage);
|
|
mainMessage = NULL;
|
|
}
|
|
|
|
if(multiparts == 0) {
|
|
if(messages)
|
|
free(messages);
|
|
return 2; /* Nothing to do */
|
|
}
|
|
|
|
cli_dbgmsg("The message has %d parts\n", multiparts);
|
|
cli_dbgmsg("Find out the multipart type (%s)\n", mimeSubtype);
|
|
|
|
/*
|
|
* We now have all the parts of the multipart message
|
|
* in the messages array:
|
|
* message *messages[multiparts]
|
|
* Let's decide what to do with them all
|
|
*/
|
|
switch(tableFind(subtypeTable, mimeSubtype)) {
|
|
case RELATED:
|
|
cli_dbgmsg("Multipart related handler\n");
|
|
/*
|
|
* Have a look to see if there's HTML code
|
|
* which will need scanning
|
|
*/
|
|
aMessage = NULL;
|
|
assert(multiparts > 0);
|
|
|
|
htmltextPart = getTextPart(messages, multiparts);
|
|
|
|
if(htmltextPart >= 0)
|
|
aText = textAddMessage(aText, messages[htmltextPart]);
|
|
else
|
|
/*
|
|
* There isn't an HTML bit. If there's a
|
|
* multipart bit, it'll may be in there
|
|
* somewhere
|
|
*/
|
|
for(i = 0; i < multiparts; i++)
|
|
if(messageGetMimeType(messages[i]) == MULTIPART) {
|
|
aMessage = messages[i];
|
|
htmltextPart = i;
|
|
break;
|
|
}
|
|
|
|
if(htmltextPart == -1)
|
|
cli_dbgmsg("No HTML code found to be scanned");
|
|
else {
|
|
rc = parseEmailBody(aMessage, aText, dir, rfc821Table, subtypeTable, options);
|
|
if(rc == 1) {
|
|
assert(aMessage == messages[htmltextPart]);
|
|
messageDestroy(aMessage);
|
|
messages[htmltextPart] = NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Fixed based on an idea from Stephen White <stephen@earth.li>
|
|
* The message is confused about the difference
|
|
* between alternative and related. Badtrans.B
|
|
* suffers from this problem.
|
|
*
|
|
* Fall through in this case:
|
|
* Content-Type: multipart/related;
|
|
* type="multipart/alternative"
|
|
*/
|
|
/*
|
|
* Changed to always fall through based on
|
|
* an idea from Michael Dankov <misha@btrc.ru>
|
|
* that some viruses are completely confused
|
|
* about the difference between related
|
|
* and mixed
|
|
*/
|
|
/*cptr = messageFindArgument(mainMessage, "type");
|
|
if(cptr == NULL)
|
|
break;
|
|
isAlternative = (bool)(strcasecmp(cptr, "multipart/alternative") == 0);
|
|
free((char *)cptr);
|
|
if(!isAlternative)
|
|
break;*/
|
|
case DIGEST:
|
|
/*
|
|
* According to section 5.1.5 RFC2046, the
|
|
* default mime type of multipart/digest parts
|
|
* is message/rfc822
|
|
*
|
|
* We consider them as alternative, wrong in
|
|
* the strictest sense since they aren't
|
|
* alternatives - all parts a valid - but it's
|
|
* OK for our needs since it means each part
|
|
* will be scanned
|
|
*/
|
|
case ALTERNATIVE:
|
|
cli_dbgmsg("Multipart alternative handler\n");
|
|
|
|
/*
|
|
* Fall through - some clients are broken and
|
|
* say alternative instead of mixed. The Klez
|
|
* virus is broken that way, and anyway we
|
|
* wish to scan all of the alternatives
|
|
*/
|
|
case REPORT:
|
|
/*
|
|
* According to section 1 of RFC1892, the
|
|
* syntax of multipart/report is the same
|
|
* as multipart/mixed. There are some required
|
|
* parameters, but there's no need for us to
|
|
* verify that they exist
|
|
*/
|
|
case MIXED:
|
|
case APPLEDOUBLE: /* not really supported */
|
|
/*
|
|
* Look for attachments
|
|
*
|
|
* Not all formats are supported. If an
|
|
* unsupported format turns out to be
|
|
* common enough to implement, it is a simple
|
|
* matter to add it
|
|
*/
|
|
if(aText) {
|
|
if(mainMessage && (mainMessage != messageIn))
|
|
messageDestroy(mainMessage);
|
|
mainMessage = NULL;
|
|
}
|
|
|
|
cli_dbgmsg("Mixed message with %d parts\n", multiparts);
|
|
for(i = 0; i < multiparts; i++) {
|
|
bool addToText = FALSE;
|
|
const char *dtype;
|
|
#ifndef SAVE_TO_DISC
|
|
message *body;
|
|
#endif
|
|
|
|
aMessage = messages[i];
|
|
|
|
if(aMessage == NULL)
|
|
continue;
|
|
|
|
cli_dbgmsg("Mixed message part %d is of type %d\n",
|
|
i, messageGetMimeType(aMessage));
|
|
|
|
switch(messageGetMimeType(aMessage)) {
|
|
case APPLICATION:
|
|
case AUDIO:
|
|
case IMAGE:
|
|
case VIDEO:
|
|
break;
|
|
case NOMIME:
|
|
cli_dbgmsg("No mime headers found in multipart part %d\n", i);
|
|
if(mainMessage) {
|
|
if(binhexBegin(aMessage)) {
|
|
cli_dbgmsg("Found binhex message in multipart/mixed mainMessage\n");
|
|
messageSetEncoding(mainMessage, "x-bunhex");
|
|
fb = messageToFileblob(mainMessage, dir);
|
|
|
|
if(fb)
|
|
fileblobDestroy(fb);
|
|
}
|
|
if(mainMessage != messageIn)
|
|
messageDestroy(mainMessage);
|
|
mainMessage = NULL;
|
|
} else if(aMessage) {
|
|
if(binhexBegin(aMessage)) {
|
|
cli_dbgmsg("Found binhex message in multipart/mixed non mime part\n");
|
|
messageSetEncoding(aMessage, "x-binhex");
|
|
fb = messageToFileblob(aMessage, dir);
|
|
|
|
if(fb)
|
|
fileblobDestroy(fb);
|
|
assert(aMessage == messages[i]);
|
|
messageReset(messages[i]);
|
|
}
|
|
}
|
|
addToText = TRUE;
|
|
if(messageGetBody(aMessage) == NULL)
|
|
/*
|
|
* No plain text version
|
|
*/
|
|
cli_dbgmsg("No plain text alternative");
|
|
break;
|
|
case TEXT:
|
|
dtype = messageGetDispositionType(aMessage);
|
|
cli_dbgmsg("Mixed message text part disposition \"%s\"\n",
|
|
dtype);
|
|
if(strcasecmp(dtype, "attachment") == 0)
|
|
break;
|
|
if((*dtype == '\0') || (strcasecmp(dtype, "inline") == 0)) {
|
|
if(mainMessage && (mainMessage != messageIn))
|
|
messageDestroy(mainMessage);
|
|
mainMessage = NULL;
|
|
cptr = messageGetMimeSubtype(aMessage);
|
|
cli_dbgmsg("Mime subtype \"%s\"\n", cptr);
|
|
if((tableFind(subtypeTable, cptr) == PLAIN) &&
|
|
(messageGetEncoding(aMessage) == NOENCODING)) {
|
|
char *filename;
|
|
/*
|
|
* Strictly speaking
|
|
* a text/plain part is
|
|
* not an attachment. We
|
|
* pretend it is so that
|
|
* we can decode and
|
|
* scan it
|
|
*/
|
|
filename = (char *)messageFindArgument(aMessage, "filename");
|
|
if(filename == NULL)
|
|
filename = (char *)messageFindArgument(aMessage, "name");
|
|
|
|
if(filename == NULL) {
|
|
cli_dbgmsg("Adding part to main message\n");
|
|
addToText = TRUE;
|
|
} else {
|
|
cli_dbgmsg("Treating %s as attachment\n",
|
|
filename);
|
|
free(filename);
|
|
}
|
|
} else {
|
|
if(options&CL_SCAN_MAILURL)
|
|
if(tableFind(subtypeTable, cptr) == HTML)
|
|
checkURLs(aMessage, dir);
|
|
messageAddArgument(aMessage, "filename=mixedtextportion");
|
|
}
|
|
} else {
|
|
cli_dbgmsg("Text type %s is not supported\n", dtype);
|
|
continue;
|
|
}
|
|
break;
|
|
case MESSAGE:
|
|
/* Content-Type: message/rfc822 */
|
|
cli_dbgmsg("Found message inside multipart (encoding type %d)\n",
|
|
messageGetEncoding(aMessage));
|
|
switch(messageGetEncoding(aMessage)) {
|
|
case NOENCODING:
|
|
case EIGHTBIT:
|
|
case BINARY:
|
|
if(encodingLine(aMessage) == NULL) {
|
|
/*
|
|
* This means that the message has no attachments
|
|
* The test for messageGetEncoding is needed since
|
|
* encodingLine won't have been set if the message
|
|
* itself has been encoded
|
|
*/
|
|
cli_dbgmsg("No encoding line found in the multipart/message\n");
|
|
assert(aMessage == messages[i]);
|
|
messageDestroy(messages[i]);
|
|
messages[i] = NULL;
|
|
continue;
|
|
}
|
|
}
|
|
#if 0
|
|
messageAddStrAtTop(aMessage,
|
|
"Received: by clamd (message/rfc822)");
|
|
#endif
|
|
#ifdef SAVE_TO_DISC
|
|
/*
|
|
* Save this embedded message
|
|
* to a temporary file
|
|
*/
|
|
saveTextPart(aMessage, dir);
|
|
assert(aMessage == messages[i]);
|
|
messageDestroy(messages[i]);
|
|
messages[i] = NULL;
|
|
#else
|
|
/*
|
|
* Scan in memory, faster but
|
|
* is open to DoS attacks when
|
|
* many nested levels are
|
|
* involved.
|
|
*/
|
|
body = parseEmailHeaders(aMessage, rfc821Table, TRUE);
|
|
/*
|
|
* We've fininished with the
|
|
* original copy of the message,
|
|
* so throw that away and
|
|
* deal with the encapsulated
|
|
* message as a message.
|
|
* This can save a lot of memory
|
|
*/
|
|
assert(aMessage == messages[i]);
|
|
messageDestroy(messages[i]);
|
|
messages[i] = NULL;
|
|
if(body) {
|
|
rc = parseEmailBody(body, NULL, dir, rfc821Table, subtypeTable, options);
|
|
messageDestroy(body);
|
|
}
|
|
#endif
|
|
continue;
|
|
case MULTIPART:
|
|
/*
|
|
* It's a multi part within a multi part
|
|
* Run the message parser on this bit, it won't
|
|
* be an attachment
|
|
*/
|
|
cli_dbgmsg("Found multipart inside multipart\n");
|
|
if(aMessage) {
|
|
/*
|
|
* The headers were parsed when reading in the
|
|
* whole multipart section
|
|
*/
|
|
rc = parseEmailBody(aMessage, aText, dir, rfc821Table, subtypeTable, options);
|
|
cli_dbgmsg("Finished recursion\n");
|
|
assert(aMessage == messages[i]);
|
|
messageDestroy(messages[i]);
|
|
messages[i] = NULL;
|
|
} else {
|
|
rc = parseEmailBody(NULL, NULL, dir, rfc821Table, subtypeTable, options);
|
|
if(mainMessage && (mainMessage != messageIn))
|
|
messageDestroy(mainMessage);
|
|
mainMessage = NULL;
|
|
}
|
|
continue;
|
|
default:
|
|
cli_warnmsg("Only text and application attachments are supported, type = %d\n",
|
|
messageGetMimeType(aMessage));
|
|
continue;
|
|
}
|
|
|
|
if(addToText) {
|
|
cli_dbgmsg("Adding to non mime-part\n");
|
|
aText = textAdd(aText, messageGetBody(aMessage));
|
|
} else {
|
|
fb = messageToFileblob(aMessage, dir);
|
|
|
|
if(fb)
|
|
fileblobDestroy(fb);
|
|
}
|
|
assert(aMessage == messages[i]);
|
|
messageDestroy(messages[i]);
|
|
messages[i] = NULL;
|
|
}
|
|
|
|
/* rc = parseEmailBody(NULL, NULL, dir, rfc821Table, subtypeTable, options); */
|
|
break;
|
|
case SIGNED:
|
|
case PARALLEL:
|
|
/*
|
|
* If we're here it could be because we have a
|
|
* multipart/mixed message, consisting of a
|
|
* message followed by an attachment. That
|
|
* message itself is a multipart/alternative
|
|
* message and we need to dig out the plain
|
|
* text part of that alternative
|
|
*/
|
|
htmltextPart = getTextPart(messages, multiparts);
|
|
if(htmltextPart == -1)
|
|
htmltextPart = 0;
|
|
|
|
rc = parseEmailBody(messages[htmltextPart], aText, dir, rfc821Table, subtypeTable, options);
|
|
break;
|
|
case ENCRYPTED:
|
|
rc = 0;
|
|
protocol = (char *)messageFindArgument(mainMessage, "protocol");
|
|
if(protocol) {
|
|
if(strcasecmp(protocol, "application/pgp-encrypted") == 0) {
|
|
/* RFC2015 */
|
|
cli_warnmsg("PGP encoded attachment not scanned\n");
|
|
rc = 2;
|
|
} else
|
|
cli_warnmsg("Unknown encryption protocol '%s' - if you believe this file contains a virus, submit it to www.clamav.net\n", protocol);
|
|
free(protocol);
|
|
} else
|
|
cli_dbgmsg("Encryption method missing protocol name\n");
|
|
|
|
break;
|
|
default:
|
|
assert(0);
|
|
}
|
|
|
|
if(mainMessage && (mainMessage != messageIn))
|
|
messageDestroy(mainMessage);
|
|
|
|
if(aText && (textIn == NULL)) {
|
|
if((fb = fileblobCreate()) != NULL) {
|
|
cli_dbgmsg("Save non mime and/or text/plain part\n");
|
|
fileblobSetFilename(fb, dir, "textpart");
|
|
/*fileblobAddData(fb, "Received: by clamd (textpart)\n", 30);*/
|
|
(void)textToFileblob(aText, fb);
|
|
|
|
fileblobDestroy(fb);
|
|
}
|
|
textDestroy(aText);
|
|
}
|
|
|
|
for(i = 0; i < multiparts; i++)
|
|
if(messages[i])
|
|
messageDestroy(messages[i]);
|
|
|
|
if(messages)
|
|
free(messages);
|
|
|
|
return rc;
|
|
|
|
case MESSAGE:
|
|
/*
|
|
* Check for forbidden encodings
|
|
*/
|
|
switch(messageGetEncoding(mainMessage)) {
|
|
case NOENCODING:
|
|
case EIGHTBIT:
|
|
case BINARY:
|
|
break;
|
|
default:
|
|
cli_warnmsg("MIME type 'message' cannot be decoded\n");
|
|
break;
|
|
}
|
|
rc = 0;
|
|
if((strcasecmp(mimeSubtype, "rfc822") == 0) ||
|
|
(strcasecmp(mimeSubtype, "delivery-status") == 0)) {
|
|
message *m = parseEmailHeaders(mainMessage, rfc821Table);
|
|
if(m) {
|
|
cli_dbgmsg("Decode rfc822");
|
|
|
|
if(mainMessage && (mainMessage != messageIn)) {
|
|
messageDestroy(mainMessage);
|
|
mainMessage = NULL;
|
|
} else
|
|
messageReset(mainMessage);
|
|
if(messageGetBody(m))
|
|
rc = parseEmailBody(m, NULL, dir, rfc821Table, subtypeTable, options);
|
|
|
|
messageDestroy(m);
|
|
}
|
|
break;
|
|
} else if(strcasecmp(mimeSubtype, "disposition-notification") == 0) {
|
|
/* RFC 2298 - handle like a normal email */
|
|
rc = 1;
|
|
break;
|
|
} else if(strcasecmp(mimeSubtype, "partial") == 0) {
|
|
#ifdef PARTIAL_DIR
|
|
/* RFC1341 message split over many emails */
|
|
if(rfc1341(mainMessage, dir) >= 0)
|
|
rc = 1;
|
|
#else
|
|
cli_warnmsg("Partial message received from MUA/MTA - message cannot be scanned\n");
|
|
rc = 0;
|
|
#endif
|
|
} else if(strcasecmp(mimeSubtype, "external-body") == 0)
|
|
/* TODO */
|
|
cli_warnmsg("Attempt to send Content-type message/external-body trapped");
|
|
else
|
|
cli_warnmsg("Unsupported message format `%s' - if you believe this file contains a virus, submit it to www.clamav.net\n", mimeSubtype);
|
|
|
|
|
|
if(mainMessage && (mainMessage != messageIn))
|
|
messageDestroy(mainMessage);
|
|
if(messages)
|
|
free(messages);
|
|
return rc;
|
|
|
|
case APPLICATION:
|
|
/*cptr = messageGetMimeSubtype(mainMessage);
|
|
|
|
if((strcasecmp(cptr, "octet-stream") == 0) ||
|
|
(strcasecmp(cptr, "x-msdownload") == 0)) {*/
|
|
{
|
|
fb = messageToFileblob(mainMessage, dir);
|
|
|
|
if(fb) {
|
|
cli_dbgmsg("Saving main message as attachment\n");
|
|
fileblobDestroy(fb);
|
|
if(mainMessage != messageIn) {
|
|
messageDestroy(mainMessage);
|
|
mainMessage = NULL;
|
|
} else
|
|
messageReset(mainMessage);
|
|
}
|
|
} /*else
|
|
cli_warnmsg("Discarded application not sent as attachment\n");*/
|
|
break;
|
|
|
|
case AUDIO:
|
|
case VIDEO:
|
|
case IMAGE:
|
|
break;
|
|
|
|
default:
|
|
cli_warnmsg("Message received with unknown mime encoding");
|
|
break;
|
|
}
|
|
}
|
|
|
|
if(aText && (textIn == NULL)) {
|
|
/* Look for a bounce in the text (non mime encoded) portion */
|
|
const text *t;
|
|
|
|
for(t = aText; t; t = t->t_next) {
|
|
const line_t *l = t->t_line;
|
|
const text *lookahead, *topofbounce;
|
|
const char *s;
|
|
bool inheader;
|
|
|
|
if(l == NULL)
|
|
continue;
|
|
|
|
s = lineGetData(l);
|
|
|
|
if(cli_filetype(s, strlen(s)) != CL_TYPE_MAIL)
|
|
continue;
|
|
|
|
/*
|
|
* We've found what looks like the start of a bounce
|
|
* message. Only bother saving if it really is a bounce
|
|
* message, this helps to speed up scanning of ping-pong
|
|
* messages that have lots of bounces within bounces in
|
|
* them
|
|
*/
|
|
for(lookahead = t->t_next; lookahead; lookahead = lookahead->t_next) {
|
|
l = lookahead->t_line;
|
|
|
|
if(l == NULL)
|
|
break;
|
|
s = lineGetData(l);
|
|
if(strncasecmp(s, "Content-Type:", 13) == 0)
|
|
/*
|
|
* Don't bother with plain/text or
|
|
* plain/html
|
|
*/
|
|
if(strstr(s, "text/") == NULL)
|
|
/*
|
|
* Don't bother to save the unuseful
|
|
* part
|
|
*/
|
|
break;
|
|
}
|
|
|
|
if(lookahead && (lookahead->t_line == NULL)) {
|
|
cli_dbgmsg("Non mime part bounce message is not mime encoded, so it will not be scanned\n");
|
|
t = lookahead;
|
|
/* look for next bounce message */
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Prescan the bounce message to see if there's likely
|
|
* to be anything nasty.
|
|
* This algorithm is hand crafted and may be breakable
|
|
* so all submissions are welcome. It's best NOT to
|
|
* remove this however you may be tempted, because it
|
|
* significantly speeds up the scanning of multiple
|
|
* bounces (i.e. bounces within many bounces)
|
|
*/
|
|
for(; lookahead; lookahead = lookahead->t_next) {
|
|
l = lookahead->t_line;
|
|
|
|
if(l) {
|
|
s = lineGetData(l);
|
|
if((strncasecmp(s, "Content-Type:", 13) == 0) &&
|
|
(strstr(s, "multipart/") == NULL) &&
|
|
(strstr(s, "message/rfc822") == NULL) &&
|
|
(strstr(s, "text/plain") == NULL))
|
|
break;
|
|
}
|
|
}
|
|
if(lookahead == NULL) {
|
|
cli_dbgmsg("cli_mbox: I believe it's plain text which must be clean\n");
|
|
/* nothing here, move along please */
|
|
break;
|
|
}
|
|
if((fb = fileblobCreate()) == NULL)
|
|
break;
|
|
cli_dbgmsg("Save non mime part bounce message\n");
|
|
fileblobSetFilename(fb, dir, "bounce");
|
|
fileblobAddData(fb, (unsigned char *)"Received: by clamd (bounce)\n", 28);
|
|
|
|
inheader = TRUE;
|
|
topofbounce = NULL;
|
|
for(;;) {
|
|
l = t->t_line;
|
|
|
|
if(l == NULL) {
|
|
if(inheader) {
|
|
inheader = FALSE;
|
|
topofbounce = t;
|
|
}
|
|
} else {
|
|
s = lineGetData(l);
|
|
fileblobAddData(fb, (unsigned char *)s, strlen(s));
|
|
}
|
|
fileblobAddData(fb, (unsigned char *)"\n", 1);
|
|
lookahead = t->t_next;
|
|
if(lookahead == NULL)
|
|
break;
|
|
t = lookahead;
|
|
l = t->t_line;
|
|
if((!inheader) && l) {
|
|
s = lineGetData(l);
|
|
if(cli_filetype(s, strlen(s)) == CL_TYPE_MAIL) {
|
|
cli_dbgmsg("Found the start of another bounce candidate\n");
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
fileblobDestroy(fb);
|
|
if(topofbounce)
|
|
t = topofbounce;
|
|
/*
|
|
* Don't do this - it slows bugs.txt
|
|
*/
|
|
/*if(mainMessage)
|
|
mainMessage->bounce = NULL;*/
|
|
}
|
|
textDestroy(aText);
|
|
aText = NULL;
|
|
}
|
|
|
|
/*
|
|
* No attachments - scan the text portions, often files
|
|
* are hidden in HTML code
|
|
*/
|
|
cli_dbgmsg("%d multiparts found\n", multiparts);
|
|
for(i = 0; i < multiparts; i++) {
|
|
fb = messageToFileblob(messages[i], dir);
|
|
|
|
if(fb) {
|
|
cli_dbgmsg("Saving multipart %d\n", i);
|
|
|
|
fileblobDestroy(fb);
|
|
}
|
|
}
|
|
|
|
if(mainMessage) {
|
|
/*
|
|
* Look for uu-encoded main file
|
|
*/
|
|
const text *t_line;
|
|
|
|
if((encodingLine(mainMessage) != NULL) &&
|
|
((t_line = bounceBegin(mainMessage)) != NULL)) {
|
|
const text *t, *start;
|
|
/*
|
|
* Attempt to save the original (unbounced)
|
|
* message - clamscan will find that in the
|
|
* directory and call us again (with any luck)
|
|
* having found an e-mail message to handle.
|
|
*
|
|
* This finds a lot of false positives, the
|
|
* search that a content type is in the
|
|
* bounce (i.e. it's after the bounce header)
|
|
* helps a bit.
|
|
*
|
|
* messageAddLine
|
|
* optimisation could help here, but needs
|
|
* careful thought, do it with line numbers
|
|
* would be best, since the current method in
|
|
* messageAddLine of checking encoding first
|
|
* must remain otherwise non bounce messages
|
|
* won't be scanned
|
|
*/
|
|
for(t = start = t_line; t; t = t->t_next) {
|
|
char cmd[RFC2821LENGTH + 1];
|
|
const char *txt = lineGetData(t->t_line);
|
|
|
|
if(txt == NULL)
|
|
continue;
|
|
if(cli_strtokbuf(txt, 0, ":", cmd) == NULL)
|
|
continue;
|
|
|
|
switch(tableFind(rfc821Table, cmd)) {
|
|
case CONTENT_TRANSFER_ENCODING:
|
|
if((strstr(txt, "7bit") == NULL) &&
|
|
(strstr(txt, "8bit") == NULL))
|
|
break;
|
|
continue;
|
|
case CONTENT_DISPOSITION:
|
|
break;
|
|
case CONTENT_TYPE:
|
|
if(strstr(txt, "text/plain") != NULL)
|
|
t = NULL;
|
|
break;
|
|
default:
|
|
if(strcasecmp(cmd, "From") == 0)
|
|
start = t_line;
|
|
else if(strcasecmp(cmd, "Received") == 0)
|
|
start = t_line;
|
|
continue;
|
|
}
|
|
break;
|
|
}
|
|
if(t && ((fb = fileblobCreate()) != NULL)) {
|
|
cli_dbgmsg("Found a bounce message\n");
|
|
fileblobSetFilename(fb, dir, "bounce");
|
|
if(textToFileblob(start, fb) == NULL)
|
|
cli_dbgmsg("Nothing new to save in the bounce message");
|
|
else
|
|
rc = 1;
|
|
fileblobDestroy(fb);
|
|
} else
|
|
cli_dbgmsg("Not found a bounce message\n");
|
|
} else {
|
|
bool saveIt;
|
|
|
|
if(messageGetMimeType(mainMessage) == MESSAGE)
|
|
/*
|
|
* Quick peek, if the encapsulated
|
|
* message has no
|
|
* content encoding statement don't
|
|
* bother saving to scan, it's safe
|
|
*/
|
|
saveIt = (encodingLine(mainMessage) != NULL);
|
|
else if((t_line = encodingLine(mainMessage)) != NULL) {
|
|
/*
|
|
* Some bounces include the message
|
|
* body without the headers.
|
|
* FIXME: Unfortunately this generates a
|
|
* lot of false positives that a bounce
|
|
* has been found when it hasn't.
|
|
*/
|
|
if((fb = fileblobCreate()) != NULL) {
|
|
cli_dbgmsg("Found a bounce message with no header at '%s'\n",
|
|
lineGetData(t_line->t_line));
|
|
fileblobSetFilename(fb, dir, "bounce");
|
|
fileblobAddData(fb,
|
|
(const unsigned char *)"Received: by clamd (bounce)\n",
|
|
28);
|
|
|
|
fb = textToFileblob(t_line, fb);
|
|
|
|
fileblobDestroy(fb);
|
|
}
|
|
saveIt = FALSE;
|
|
} else if(multiparts == 0)
|
|
/*
|
|
* Save the entire text portion,
|
|
* since it it may be an HTML file with
|
|
* a JavaScript virus
|
|
*/
|
|
saveIt = TRUE;
|
|
else
|
|
saveIt = FALSE;
|
|
|
|
if(saveIt) {
|
|
cli_dbgmsg("Saving text part to scan\n");
|
|
/*
|
|
* TODO: May be better to save aText
|
|
*/
|
|
saveTextPart(mainMessage, dir);
|
|
if(mainMessage != messageIn) {
|
|
messageDestroy(mainMessage);
|
|
mainMessage = NULL;
|
|
} else
|
|
messageReset(mainMessage);
|
|
rc = 1;
|
|
}
|
|
}
|
|
} else
|
|
rc = (multiparts) ? 1 : 2; /* anything saved? */
|
|
|
|
if(mainMessage && (mainMessage != messageIn))
|
|
messageDestroy(mainMessage);
|
|
|
|
if(messages)
|
|
free(messages);
|
|
|
|
cli_dbgmsg("parseEmailBody() returning %d\n", rc);
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* Is the current line the start of a new section?
|
|
*
|
|
* New sections start with --boundary
|
|
*/
|
|
static int
|
|
boundaryStart(const char *line, const char *boundary)
|
|
{
|
|
char *ptr, *out;
|
|
int rc;
|
|
char buf[RFC2821LENGTH + 1];
|
|
|
|
if(line == NULL)
|
|
return 0; /* empty line */
|
|
|
|
/*cli_dbgmsg("boundaryStart: line = '%s' boundary = '%s'\n", line, boundary);*/
|
|
|
|
if((*line != '-') && (*line != '('))
|
|
return 0;
|
|
|
|
if(strchr(line, '-') == NULL)
|
|
return 0;
|
|
|
|
if(strlen(line) <= sizeof(buf)) {
|
|
out = NULL;
|
|
ptr = rfc822comments(line, buf);
|
|
} else
|
|
out = ptr = rfc822comments(line, NULL);
|
|
|
|
if(ptr == NULL)
|
|
ptr = (char *)line;
|
|
|
|
if(*ptr++ != '-') {
|
|
if(out)
|
|
free(out);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Gibe.B3 is broken, it has:
|
|
* boundary="---- =_NextPart_000_01C31177.9DC7C000"
|
|
* but it's boundaries look like
|
|
* ------ =_NextPart_000_01C31177.9DC7C000
|
|
* notice the one too few '-'.
|
|
* Presumably this is a deliberate exploitation of a bug in some mail
|
|
* clients.
|
|
*
|
|
* The trouble is that this creates a lot of false positives for
|
|
* boundary conditions, if we're too lax about matches. We do our level
|
|
* best to avoid these false positives. For example if we have
|
|
* boundary="1" we want to ensure that we don't break out of every line
|
|
* that has -1 in it instead of starting --1. This needs some more work.
|
|
*
|
|
* Look with and without RFC822 comments stripped, I've seen some
|
|
* samples where () are taken as comments in boundaries and some where
|
|
* they're not. Irrespective of whatever RFC2822 says we need to find
|
|
* viruses in both types of mails
|
|
*/
|
|
if((strstr(ptr, boundary) != NULL) || (strstr(line, boundary) != NULL))
|
|
rc = 1;
|
|
else if(*ptr++ != '-')
|
|
rc = 0;
|
|
else
|
|
rc = (strcasecmp(ptr, boundary) == 0);
|
|
|
|
if(out)
|
|
free(out);
|
|
|
|
if(rc == 1)
|
|
cli_dbgmsg("boundaryStart: found %s in %s\n", boundary, line);
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* Is the current line the end?
|
|
*
|
|
* The message ends with with --boundary--
|
|
*/
|
|
static int
|
|
endOfMessage(const char *line, const char *boundary)
|
|
{
|
|
size_t len;
|
|
|
|
if(line == NULL)
|
|
return 0;
|
|
/*cli_dbgmsg("endOfMessage: line = '%s' boundary = '%s'\n", line, boundary);*/
|
|
if(*line++ != '-')
|
|
return 0;
|
|
if(*line++ != '-')
|
|
return 0;
|
|
len = strlen(boundary);
|
|
if(strncasecmp(line, boundary, len) != 0)
|
|
return 0;
|
|
/*
|
|
* Use < rather than == because some broken mails have white
|
|
* space after the boundary
|
|
*/
|
|
if(strlen(line) < (len + 2))
|
|
return 0;
|
|
line = &line[len];
|
|
if(*line++ != '-')
|
|
return 0;
|
|
return *line == '-';
|
|
}
|
|
|
|
/*
|
|
* Initialise the various lookup tables
|
|
*/
|
|
static int
|
|
initialiseTables(table_t **rfc821Table, table_t **subtypeTable)
|
|
{
|
|
const struct tableinit *tableinit;
|
|
|
|
/*
|
|
* Initialise the various look up tables
|
|
*/
|
|
*rfc821Table = tableCreate();
|
|
assert(*rfc821Table != NULL);
|
|
|
|
for(tableinit = rfc821headers; tableinit->key; tableinit++)
|
|
if(tableInsert(*rfc821Table, tableinit->key, tableinit->value) < 0) {
|
|
tableDestroy(*rfc821Table);
|
|
*rfc821Table = NULL;
|
|
return -1;
|
|
}
|
|
|
|
*subtypeTable = tableCreate();
|
|
assert(*subtypeTable != NULL);
|
|
|
|
for(tableinit = mimeSubtypes; tableinit->key; tableinit++)
|
|
if(tableInsert(*subtypeTable, tableinit->key, tableinit->value) < 0) {
|
|
tableDestroy(*rfc821Table);
|
|
tableDestroy(*subtypeTable);
|
|
*rfc821Table = NULL;
|
|
*subtypeTable = NULL;
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* If there's a HTML text version use that, otherwise
|
|
* use the first text part, otherwise just use the
|
|
* first one around. HTML text is most likely to include
|
|
* a scripting worm
|
|
*
|
|
* If we can't find one, return -1
|
|
*/
|
|
static int
|
|
getTextPart(message *const messages[], size_t size)
|
|
{
|
|
size_t i;
|
|
int textpart = -1;
|
|
|
|
for(i = 0; i < size; i++) {
|
|
assert(messages[i] != NULL);
|
|
if(messageGetMimeType(messages[i]) == TEXT) {
|
|
if(strcasecmp(messageGetMimeSubtype(messages[i]), "html") == 0)
|
|
return (int)i;
|
|
textpart = (int)i;
|
|
}
|
|
}
|
|
return textpart;
|
|
}
|
|
|
|
/*
|
|
* strip -
|
|
* Remove the trailing spaces from a buffer. Don't call this directly,
|
|
* always call strstrip() which is a wrapper to this routine to be used with
|
|
* NUL terminated strings. This code looks a bit strange because of it's
|
|
* heritage from code that worked on strings that weren't necessarily NUL
|
|
* terminated.
|
|
* TODO: rewrite for clamAV
|
|
*
|
|
* Returns it's new length (a la strlen)
|
|
*
|
|
* len must be int not size_t because of the >= 0 test, it is sizeof(buf)
|
|
* not strlen(buf)
|
|
*/
|
|
static size_t
|
|
strip(char *buf, int len)
|
|
{
|
|
register char *ptr;
|
|
register size_t i;
|
|
|
|
if((buf == NULL) || (len <= 0))
|
|
return 0;
|
|
|
|
i = strlen(buf);
|
|
if(len > (int)(i + 1))
|
|
return i;
|
|
ptr = &buf[--len];
|
|
|
|
#if defined(UNIX) || defined(C_LINUX) || defined(C_DARWIN) /* watch - it may be in shared text area */
|
|
do
|
|
if(*ptr)
|
|
*ptr = '\0';
|
|
while((--len >= 0) && (!isgraph(*--ptr)) && (*ptr != '\n') && (*ptr != '\r'));
|
|
#else /* more characters can be displayed on DOS */
|
|
do
|
|
#ifndef REAL_MODE_DOS
|
|
if(*ptr) /* C8.0 puts into a text area */
|
|
#endif
|
|
*ptr = '\0';
|
|
while((--len >= 0) && ((*--ptr == '\0') || (isspace((int)*ptr))));
|
|
#endif
|
|
return((size_t)(len + 1));
|
|
}
|
|
|
|
/*
|
|
* strstrip:
|
|
* Strip a given string
|
|
*/
|
|
size_t
|
|
strstrip(char *s)
|
|
{
|
|
if(s == (char *)NULL)
|
|
return(0);
|
|
|
|
return(strip(s, strlen(s) + 1));
|
|
}
|
|
|
|
/*
|
|
* Some broken email headers use ';' at the end of a line to continue
|
|
* to the next line and don't add a leading white space on the next line
|
|
*/
|
|
static bool
|
|
continuationMarker(const char *line)
|
|
{
|
|
const char *ptr;
|
|
|
|
if(line == NULL)
|
|
return FALSE;
|
|
|
|
#ifdef CL_DEBUG
|
|
cli_dbgmsg("continuationMarker(%s)\n", line);
|
|
#endif
|
|
|
|
if(strlen(line) == 0)
|
|
return FALSE;
|
|
|
|
ptr = strchr(line, '\0');
|
|
|
|
assert(ptr != NULL);
|
|
|
|
while(ptr > line)
|
|
switch(*--ptr) {
|
|
case '\n':
|
|
case '\r':
|
|
case ' ':
|
|
case '\t':
|
|
continue;
|
|
case ';':
|
|
return TRUE;
|
|
default:
|
|
return FALSE;
|
|
}
|
|
|
|
return FALSE;
|
|
}
|
|
|
|
static int
|
|
parseMimeHeader(message *m, const char *cmd, const table_t *rfc821Table, const char *arg)
|
|
{
|
|
char *copy, *p;
|
|
const char *ptr;
|
|
int commandNumber;
|
|
|
|
cli_dbgmsg("parseMimeHeader: cmd='%s', arg='%s'\n", cmd, arg);
|
|
|
|
copy = rfc822comments(cmd, NULL);
|
|
if(copy) {
|
|
commandNumber = tableFind(rfc821Table, copy);
|
|
free(copy);
|
|
} else
|
|
commandNumber = tableFind(rfc821Table, cmd);
|
|
|
|
copy = rfc822comments(arg, NULL);
|
|
|
|
if(copy)
|
|
ptr = copy;
|
|
else
|
|
ptr = arg;
|
|
|
|
switch(commandNumber) {
|
|
case CONTENT_TYPE:
|
|
/*
|
|
* Fix for non RFC1521 compliant mailers
|
|
* that send content-type: Text instead
|
|
* of content-type: Text/Plain, or
|
|
* just simply "Content-Type:"
|
|
*/
|
|
if(arg == NULL)
|
|
/*
|
|
* According to section 4 of RFC1521:
|
|
* "Note also that a subtype specification is
|
|
* MANDATORY. There are no default subtypes"
|
|
*
|
|
* We have to break this and make an assumption
|
|
* for the subtype because virus writers and
|
|
* email client writers don't get it right
|
|
*/
|
|
cli_warnmsg("Empty content-type received, no subtype specified, assuming text/plain; charset=us-ascii\n");
|
|
else if(strchr(ptr, '/') == NULL)
|
|
/*
|
|
* Empty field, such as
|
|
* Content-Type:
|
|
* which I believe is illegal according to
|
|
* RFC1521
|
|
*/
|
|
cli_dbgmsg("Invalid content-type '%s' received, no subtype specified, assuming text/plain; charset=us-ascii\n", ptr);
|
|
else {
|
|
int i;
|
|
char *mimeArgs; /* RHS of the ; */
|
|
|
|
/*
|
|
* Some clients are broken and
|
|
* put white space after the ;
|
|
*/
|
|
if(*arg == '/') {
|
|
cli_warnmsg("Content-type '/' received, assuming application/octet-stream\n");
|
|
messageSetMimeType(m, "application");
|
|
messageSetMimeSubtype(m, "octet-stream");
|
|
} else {
|
|
/*
|
|
* The content type could be in quotes:
|
|
* Content-Type: "multipart/mixed"
|
|
* FIXME: this is a hack in that ignores
|
|
* the quotes, it doesn't handle
|
|
* them properly
|
|
*/
|
|
while(isspace(*ptr))
|
|
ptr++;
|
|
if(ptr[0] == '\"')
|
|
ptr++;
|
|
|
|
if(ptr[0] != '/') {
|
|
char *s;
|
|
char *mimeType; /* LHS of the ; */
|
|
#ifdef CL_THREAD_SAFE
|
|
char *strptr;
|
|
#endif
|
|
|
|
s = mimeType = cli_strtok(ptr, 0, ";");
|
|
/*
|
|
* Handle
|
|
* Content-Type: foo/bar multipart/mixed
|
|
* and
|
|
* Content-Type: multipart/mixed foo/bar
|
|
*/
|
|
if(s && *s) for(;;) {
|
|
#ifdef CL_THREAD_SAFE
|
|
int set = messageSetMimeType(m, strtok_r(s, "/", &strptr));
|
|
#else
|
|
int set = messageSetMimeType(m, strtok(s, "/"));
|
|
#endif
|
|
|
|
/*
|
|
* Stephen White <stephen@earth.li>
|
|
* Some clients put space after
|
|
* the mime type but before
|
|
* the ;
|
|
*/
|
|
#ifdef CL_THREAD_SAFE
|
|
s = strtok_r(NULL, ";", &strptr);
|
|
#else
|
|
s = strtok(NULL, ";");
|
|
#endif
|
|
if(s == NULL)
|
|
break;
|
|
if(set) {
|
|
size_t len = strstrip(s) - 1;
|
|
if(s[len] == '\"') {
|
|
s[len] = '\0';
|
|
len = strstrip(s);
|
|
}
|
|
if(len) {
|
|
if(strchr(s, ' ')) {
|
|
char *t = cli_strtok(s, 0, " ");
|
|
|
|
messageSetMimeSubtype(m, t);
|
|
free(t);
|
|
} else
|
|
messageSetMimeSubtype(m, s);
|
|
}
|
|
}
|
|
|
|
while(*s && !isspace(*s))
|
|
s++;
|
|
if(*s++ == '\0')
|
|
break;
|
|
if(*s == '\0')
|
|
break;
|
|
}
|
|
if(mimeType)
|
|
free(mimeType);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Add in all rest of the the arguments.
|
|
* e.g. if the header is this:
|
|
* Content-Type:', arg='multipart/mixed; boundary=foo
|
|
* we find the boundary argument set it
|
|
*/
|
|
i = 1;
|
|
while((mimeArgs = cli_strtok(ptr, i++, ";")) != NULL) {
|
|
cli_dbgmsg("mimeArgs = '%s'\n", mimeArgs);
|
|
|
|
messageAddArguments(m, mimeArgs);
|
|
free(mimeArgs);
|
|
}
|
|
}
|
|
break;
|
|
case CONTENT_TRANSFER_ENCODING:
|
|
messageSetEncoding(m, ptr);
|
|
break;
|
|
case CONTENT_DISPOSITION:
|
|
p = cli_strtok(ptr, 0, ";");
|
|
if(p) {
|
|
if(*p) {
|
|
messageSetDispositionType(m, p);
|
|
free(p);
|
|
p = cli_strtok(ptr, 1, ";");
|
|
messageAddArgument(m, p);
|
|
}
|
|
free(p);
|
|
}
|
|
if((p = (char *)messageFindArgument(m, "filename")) == NULL)
|
|
/*
|
|
* Handle this type of header, without
|
|
* a filename (e.g. some Worm.Torvil.D)
|
|
* Content-ID: <nRfkHdrKsAxRU>
|
|
* Content-Transfer-Encoding: base64
|
|
* Content-Disposition: attachment
|
|
*/
|
|
messageAddArgument(m, "filename=unknown");
|
|
else
|
|
free(p);
|
|
}
|
|
if(copy)
|
|
free(copy);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Save the text portion of the message
|
|
*/
|
|
static void
|
|
saveTextPart(message *m, const char *dir)
|
|
{
|
|
fileblob *fb;
|
|
|
|
messageAddArgument(m, "filename=textportion");
|
|
if((fb = messageToFileblob(m, dir)) != NULL) {
|
|
/*
|
|
* Save main part to scan that
|
|
*/
|
|
cli_dbgmsg("Saving main message\n");
|
|
|
|
fileblobDestroy(fb);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Handle RFC822 comments in headers.
|
|
* If out == NULL, return a buffer without the comments, the caller must free
|
|
* the returned buffer
|
|
* Return NULL on error or if the input * has no comments.
|
|
* See secion 3.4.3 of RFC822
|
|
* TODO: handle comments that go on to more than one line
|
|
*/
|
|
static char *
|
|
rfc822comments(const char *in, char *out)
|
|
{
|
|
const char *iptr;
|
|
char *optr;
|
|
int backslash, inquote, commentlevel;
|
|
|
|
if(in == NULL)
|
|
return NULL;
|
|
|
|
if(strchr(in, '(') == NULL)
|
|
return NULL;
|
|
|
|
assert(out != in);
|
|
|
|
if(out == NULL) {
|
|
out = cli_malloc(strlen(in) + 1);
|
|
if(out == NULL)
|
|
return NULL;
|
|
}
|
|
|
|
backslash = commentlevel = inquote = 0;
|
|
optr = out;
|
|
|
|
cli_dbgmsg("rfc822comments: contains a comment\n");
|
|
|
|
for(iptr = in; *iptr; iptr++)
|
|
if(backslash) {
|
|
if(commentlevel == 0)
|
|
*optr++ = *iptr;
|
|
backslash = 0;
|
|
} else switch(*iptr) {
|
|
case '\\':
|
|
backslash = 1;
|
|
break;
|
|
case '\"':
|
|
*optr++ = '\"';
|
|
inquote = !inquote;
|
|
break;
|
|
case '(':
|
|
if(inquote)
|
|
*optr++ = '(';
|
|
else
|
|
commentlevel++;
|
|
break;
|
|
case ')':
|
|
if(inquote)
|
|
*optr++ = ')';
|
|
else if(commentlevel > 0)
|
|
commentlevel--;
|
|
break;
|
|
default:
|
|
if(commentlevel == 0)
|
|
*optr++ = *iptr;
|
|
}
|
|
|
|
if(backslash) /* last character was a single backslash */
|
|
*optr++ = '\\';
|
|
*optr = '\0';
|
|
|
|
/*strstrip(out);*/
|
|
|
|
cli_dbgmsg("rfc822comments '%s'=>'%s'\n", in, out);
|
|
|
|
return out;
|
|
}
|
|
|
|
/*
|
|
* Handle RFC2047 encoding. Returns a malloc'd buffer that the caller must
|
|
* free, or NULL on error
|
|
*/
|
|
static char *
|
|
rfc2047(const char *in)
|
|
{
|
|
char *out, *pout;
|
|
size_t len;
|
|
|
|
if((strstr(in, "=?") == NULL) || (strstr(in, "?=") == NULL))
|
|
return strdup(in);
|
|
|
|
cli_dbgmsg("rfc2047 '%s'\n", in);
|
|
out = cli_malloc(strlen(in) + 1);
|
|
|
|
if(out == NULL)
|
|
return NULL;
|
|
|
|
pout = out;
|
|
|
|
/* For each RFC2047 string */
|
|
while(*in) {
|
|
char encoding, *ptr, *enctext;
|
|
message *m;
|
|
blob *b;
|
|
|
|
/* Find next RFC2047 string */
|
|
while(*in) {
|
|
if((*in == '=') && (in[1] == '?')) {
|
|
in += 2;
|
|
break;
|
|
}
|
|
*pout++ = *in++;
|
|
}
|
|
/* Skip over charset, find encoding */
|
|
while((*in != '?') && *in)
|
|
in++;
|
|
if(*in == '\0')
|
|
break;
|
|
encoding = *++in;
|
|
encoding = tolower(encoding);
|
|
|
|
if((encoding != 'q') && (encoding != 'b')) {
|
|
cli_warnmsg("Unsupported RFC2047 encoding type '%c' - if you believe this file contains a virus, submit it to www.clamav.net\n", encoding);
|
|
free(out);
|
|
out = NULL;
|
|
break;
|
|
}
|
|
/* Skip to encoded text */
|
|
if(*++in != '?')
|
|
break;
|
|
if(*++in == '\0')
|
|
break;
|
|
|
|
enctext = strdup(in);
|
|
if(enctext == NULL) {
|
|
free(out);
|
|
out = NULL;
|
|
break;
|
|
}
|
|
in = strstr(in, "?=");
|
|
if(in == NULL) {
|
|
free(enctext);
|
|
break;
|
|
}
|
|
in += 2;
|
|
ptr = strstr(enctext, "?=");
|
|
assert(ptr != NULL);
|
|
*ptr = '\0';
|
|
/*cli_dbgmsg("Need to decode '%s' with method '%c'\n", enctext, encoding);*/
|
|
|
|
m = messageCreate();
|
|
if(m == NULL)
|
|
break;
|
|
messageAddStr(m, enctext);
|
|
free(enctext);
|
|
switch(encoding) {
|
|
case 'q':
|
|
messageSetEncoding(m, "quoted-printable");
|
|
break;
|
|
case 'b':
|
|
messageSetEncoding(m, "base64");
|
|
break;
|
|
}
|
|
b = messageToBlob(m);
|
|
len = blobGetDataSize(b);
|
|
cli_dbgmsg("Decoded as '%*.*s'\n", len, len, blobGetData(b));
|
|
memcpy(pout, blobGetData(b), len);
|
|
blobDestroy(b);
|
|
messageDestroy(m);
|
|
if(pout[len - 1] == '\n')
|
|
pout += len - 1;
|
|
else
|
|
pout += len;
|
|
|
|
}
|
|
if(out == NULL)
|
|
return NULL;
|
|
|
|
*pout = '\0';
|
|
|
|
cli_dbgmsg("rfc2047 returns '%s'\n", out);
|
|
return out;
|
|
}
|
|
|
|
#ifdef PARTIAL_DIR
|
|
/*
|
|
* Handle partial messages
|
|
*/
|
|
static int
|
|
rfc1341(message *m, const char *dir)
|
|
{
|
|
fileblob *fb;
|
|
char *arg, *id, *number, *total, *oldfilename;
|
|
const char *tmpdir;
|
|
char pdir[NAME_MAX + 1];
|
|
|
|
id = (char *)messageFindArgument(m, "id");
|
|
if(id == NULL)
|
|
return -1;
|
|
|
|
#ifdef CYGWIN
|
|
if((tmpdir = getenv("TEMP")) == (char *)NULL)
|
|
if((tmpdir = getenv("TMP")) == (char *)NULL)
|
|
if((tmpdir = getenv("TMPDIR")) == (char *)NULL)
|
|
tmpdir = "C:\\";
|
|
#else
|
|
if((tmpdir = getenv("TMPDIR")) == (char *)NULL)
|
|
if((tmpdir = getenv("TMP")) == (char *)NULL)
|
|
if((tmpdir = getenv("TEMP")) == (char *)NULL)
|
|
#ifdef P_tmpdir
|
|
tmpdir = P_tmpdir;
|
|
#else
|
|
tmpdir = "/tmp";
|
|
#endif
|
|
#endif
|
|
|
|
snprintf(pdir, sizeof(pdir) - 1, "%s/clamav-partial", tmpdir);
|
|
|
|
if((mkdir(pdir, 0700) < 0) && (errno != EEXIST)) {
|
|
cli_errmsg("Can't create the directory '%s'\n", pdir);
|
|
return -1;
|
|
} else {
|
|
struct stat statb;
|
|
|
|
if(stat(pdir, &statb) < 0) {
|
|
cli_errmsg("Can't stat the directory '%s'\n", pdir);
|
|
return -1;
|
|
}
|
|
if(statb.st_mode & 077)
|
|
cli_warnmsg("Insecure partial directory %s (mode 0%o)\n",
|
|
pdir, statb.st_mode & 0777);
|
|
}
|
|
|
|
number = (char *)messageFindArgument(m, "number");
|
|
if(number == NULL) {
|
|
free(id);
|
|
return -1;
|
|
}
|
|
|
|
oldfilename = (char *)messageFindArgument(m, "filename");
|
|
if(oldfilename == NULL)
|
|
oldfilename = (char *)messageFindArgument(m, "name");
|
|
|
|
arg = cli_malloc(10 + strlen(id) + strlen(number));
|
|
if(arg) {
|
|
sprintf(arg, "filename=%s%s", id, number);
|
|
messageAddArgument(m, arg);
|
|
free(arg);
|
|
}
|
|
|
|
if(oldfilename) {
|
|
cli_warnmsg("Must reset to %s\n", oldfilename);
|
|
free(oldfilename);
|
|
}
|
|
|
|
if((fb = messageToFileblob(m, pdir)) == NULL) {
|
|
free(id);
|
|
free(number);
|
|
return -1;
|
|
}
|
|
|
|
fileblobDestroy(fb);
|
|
|
|
total = (char *)messageFindArgument(m, "total");
|
|
cli_dbgmsg("rfc1341: %s, %s of %s\n", id, number, (total) ? total : "?");
|
|
if(total) {
|
|
int n = atoi(number);
|
|
int t = atoi(total);
|
|
DIR *dd = NULL;
|
|
|
|
free(total);
|
|
/*
|
|
* If it's the last one - reassemble it
|
|
* FIXME: this assumes that we receive the parts in order
|
|
*/
|
|
if((n == t) && ((dd = opendir(pdir)) != NULL)) {
|
|
FILE *fout;
|
|
char outname[NAME_MAX + 1];
|
|
time_t now;
|
|
|
|
snprintf(outname, sizeof(outname) - 1, "%s/%s", dir, id);
|
|
|
|
cli_dbgmsg("outname: %s\n", outname);
|
|
|
|
fout = fopen(outname, "wb");
|
|
if(fout == NULL) {
|
|
cli_errmsg("Can't open '%s' for writing", outname);
|
|
free(id);
|
|
free(number);
|
|
closedir(dd);
|
|
return -1;
|
|
}
|
|
|
|
time(&now);
|
|
for(n = 1; n <= t; n++) {
|
|
char filename[NAME_MAX + 1];
|
|
const struct dirent *dent;
|
|
#if defined(HAVE_READDIR_R_3) || defined(HAVE_READDIR_R_2)
|
|
union {
|
|
struct dirent d;
|
|
char b[offsetof(struct dirent, d_name) + NAME_MAX + 1];
|
|
} result;
|
|
#endif
|
|
|
|
snprintf(filename, sizeof(filename), "%s%d", id, n);
|
|
|
|
#ifdef HAVE_READDIR_R_3
|
|
while((readdir_r(dd, &result.d, &dent) == 0) && dent) {
|
|
#elif defined(HAVE_READDIR_R_2)
|
|
while((dent = (struct dirent *)readdir_r(dd, &result.d))) {
|
|
#else /*!HAVE_READDIR_R*/
|
|
while((dent = readdir(dd))) {
|
|
#endif
|
|
FILE *fin;
|
|
char buffer[BUFSIZ], fullname[NAME_MAX + 1];
|
|
int nblanks;
|
|
extern short cli_leavetemps_flag;
|
|
struct stat statb;
|
|
|
|
if(dent->d_ino == 0)
|
|
continue;
|
|
|
|
snprintf(fullname, sizeof(fullname) - 1,
|
|
"%s/%s", pdir, dent->d_name);
|
|
|
|
if(strncmp(filename, dent->d_name, strlen(filename)) != 0) {
|
|
if(!cli_leavetemps_flag)
|
|
continue;
|
|
if(stat(fullname, &statb) < 0)
|
|
continue;
|
|
if(now - statb.st_mtime > (time_t)(7 * 24 * 3600))
|
|
if(unlink(fullname) >= 0)
|
|
cli_warnmsg("removed old RFC1341 file %s\n", fullname);
|
|
continue;
|
|
}
|
|
|
|
fin = fopen(fullname, "rb");
|
|
if(fin == NULL) {
|
|
cli_errmsg("Can't open '%s' for reading", fullname);
|
|
fclose(fout);
|
|
unlink(outname);
|
|
free(id);
|
|
free(number);
|
|
closedir(dd);
|
|
return -1;
|
|
}
|
|
nblanks = 0;
|
|
while(fgets(buffer, sizeof(buffer) - 1, fin) != NULL)
|
|
/*
|
|
* Ensure that trailing newlines
|
|
* aren't copied
|
|
*/
|
|
if(buffer[0] == '\n')
|
|
nblanks++;
|
|
else {
|
|
if(nblanks)
|
|
do
|
|
putc('\n', fout);
|
|
while(--nblanks > 0);
|
|
fputs(buffer, fout);
|
|
}
|
|
fclose(fin);
|
|
|
|
/* don't unlink if leave temps */
|
|
if(!cli_leavetemps_flag)
|
|
unlink(fullname);
|
|
break;
|
|
}
|
|
rewinddir(dd);
|
|
}
|
|
closedir(dd);
|
|
fclose(fout);
|
|
}
|
|
}
|
|
free(number);
|
|
free(id);
|
|
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
#if defined(FOLLOWURLS) && (FOLLOWURLS > 0)
|
|
static void
|
|
checkURLs(message *m, const char *dir)
|
|
{
|
|
blob *b = messageToBlob(m);
|
|
size_t len;
|
|
table_t *t;
|
|
int i, n;
|
|
#if defined(WITH_CURL) && defined(CL_THREAD_SAFE)
|
|
pthread_t tid[FOLLOWURLS];
|
|
struct arg args[FOLLOWURLS];
|
|
#endif
|
|
tag_arguments_t hrefs;
|
|
|
|
if(b == NULL)
|
|
return;
|
|
|
|
len = blobGetDataSize(b);
|
|
|
|
if(len == 0) {
|
|
blobDestroy(b);
|
|
return;
|
|
}
|
|
|
|
/* TODO: make this size customisable */
|
|
if(len > 100*1024) {
|
|
cli_warnmsg("Viruses pointed to by URL not scanned in large message\n");
|
|
blobDestroy(b);
|
|
return;
|
|
}
|
|
|
|
blobClose(b);
|
|
t = tableCreate();
|
|
if(t == NULL) {
|
|
blobDestroy(b);
|
|
return;
|
|
}
|
|
|
|
hrefs.count = 0;
|
|
hrefs.tag = hrefs.value = NULL;
|
|
|
|
cli_dbgmsg("checkURLs: calling html_normalise_mem\n");
|
|
if(!html_normalise_mem(blobGetData(b), len, NULL, &hrefs)) {
|
|
blobDestroy(b);
|
|
tableDestroy(t);
|
|
return;
|
|
}
|
|
cli_dbgmsg("checkURLs: html_normalise_mem returned\n");
|
|
|
|
/* TODO: Do we need to call remove_html_comments? */
|
|
|
|
n = 0;
|
|
|
|
for(i = 0; i < hrefs.count; i++) {
|
|
const char *url = (const char *)hrefs.value[i];
|
|
|
|
/*
|
|
* TODO: If it's an image source, it'd be nice to note beacons
|
|
* where width="0" height="0", which needs support from
|
|
* the HTML normalise code
|
|
*/
|
|
if(strncasecmp("http://", url, 7) == 0) {
|
|
char *ptr;
|
|
#ifdef WITH_CURL
|
|
#ifndef CL_THREAD_SAFE
|
|
struct arg arg;
|
|
#endif
|
|
|
|
#else /*!WITH_CURL*/
|
|
#ifdef CL_THREAD_SAFE
|
|
static pthread_mutex_t system_mutex = PTHREAD_MUTEX_INITIALIZER;
|
|
#endif
|
|
struct stat statb;
|
|
char cmd[512];
|
|
#endif /*WITH_CURL*/
|
|
char name[NAME_MAX + 1];
|
|
|
|
if(tableFind(t, url) == 1) {
|
|
cli_dbgmsg("URL %s already downloaded\n", url);
|
|
continue;
|
|
}
|
|
/*
|
|
* What about foreign character spoofing?
|
|
* It would be useful be able to check if url
|
|
* is the same as the text displayed, e.g.
|
|
* <a href="http://dodgy.biz">www.paypal.com</a>
|
|
* but that needs support from HTML normalise
|
|
*/
|
|
if(strchr(url, '%') && strchr(url, '@'))
|
|
cli_warnmsg("Possible URL spoofing attempt noticed, but not yet handled (%s)\n", url);
|
|
|
|
if(n == FOLLOWURLS) {
|
|
cli_warnmsg("URL %s will not be scanned\n", url);
|
|
break;
|
|
}
|
|
|
|
(void)tableInsert(t, url, 1);
|
|
cli_dbgmsg("Downloading URL %s to be scanned\n", url);
|
|
strncpy(name, url, sizeof(name) - 1);
|
|
name[sizeof(name) - 1] = '\0';
|
|
for(ptr = name; *ptr; ptr++)
|
|
if(*ptr == '/')
|
|
*ptr = '_';
|
|
|
|
#ifdef WITH_CURL
|
|
#ifdef CL_THREAD_SAFE
|
|
args[n].dir = dir;
|
|
args[n].url = url;
|
|
args[n].filename = strdup(name);
|
|
pthread_create(&tid[n], NULL, getURL, &args[n]);
|
|
#else
|
|
arg.url = url;
|
|
arg.dir = dir;
|
|
arg.filename = name;
|
|
getURL(&arg);
|
|
#endif
|
|
|
|
#else
|
|
/*
|
|
* TODO: maximum size and timeouts
|
|
*/
|
|
len = sizeof(cmd) - 26 - strlen(dir) - strlen(name);
|
|
#ifdef CL_DEBUG
|
|
snprintf(cmd, sizeof(cmd) - 1, "GET -t10 \"%.*s\" >%s/%s", len, url, dir, name);
|
|
#else
|
|
snprintf(cmd, sizeof(cmd) - 1, "GET -t10 \"%.*s\" >%s/%s 2>/dev/null", len, url, dir, name);
|
|
#endif
|
|
cmd[sizeof(cmd) - 1] = '\0';
|
|
|
|
cli_dbgmsg("%s\n", cmd);
|
|
#ifdef CL_THREAD_SAFE
|
|
pthread_mutex_lock(&system_mutex);
|
|
#endif
|
|
system(cmd);
|
|
#ifdef CL_THREAD_SAFE
|
|
pthread_mutex_unlock(&system_mutex);
|
|
#endif
|
|
snprintf(cmd, sizeof(cmd), "%s/%s", dir, name);
|
|
if(stat(cmd, &statb) >= 0)
|
|
if(statb.st_size == 0) {
|
|
cli_warnmsg("URL %s failed to download\n", url);
|
|
/*
|
|
* Don't bother scanning an empty file
|
|
*/
|
|
(void)unlink(cmd);
|
|
}
|
|
#endif
|
|
++n;
|
|
}
|
|
}
|
|
blobDestroy(b);
|
|
tableDestroy(t);
|
|
|
|
#if defined(WITH_CURL) && defined(CL_THREAD_SAFE)
|
|
assert(n <= FOLLOWURLS);
|
|
cli_dbgmsg("checkURLs: waiting for %d thread(s) to finish\n", n);
|
|
while(--n >= 0) {
|
|
pthread_join(tid[n], NULL);
|
|
free(args[n].filename);
|
|
}
|
|
#endif
|
|
html_tag_arg_free(&hrefs);
|
|
}
|
|
|
|
/*
|
|
* Includes some Win32 patches by Gianluigi Tiesi <sherpya@netfarm.it>
|
|
*/
|
|
#ifdef WITH_CURL
|
|
static void *
|
|
#ifdef CL_THREAD_SAFE
|
|
getURL(void *a)
|
|
#else
|
|
getURL(struct arg *arg)
|
|
#endif
|
|
{
|
|
CURL *curl;
|
|
FILE *fp;
|
|
struct curl_slist *headers;
|
|
static int initialised = 0;
|
|
#ifdef CL_THREAD_SAFE
|
|
static pthread_mutex_t init_mutex = PTHREAD_MUTEX_INITIALIZER;
|
|
struct arg *arg = (struct arg *)a;
|
|
#endif
|
|
const char *url = arg->url;
|
|
const char *dir = arg->dir;
|
|
const char *filename = arg->filename;
|
|
char fout[NAME_MAX + 1];
|
|
#ifdef CURLOPT_ERRORBUFFER
|
|
char errorbuffer[CURL_ERROR_SIZE];
|
|
#elif (LIBCURL_VERSION_NUM >= 0x070C00)
|
|
CURLcode res = CURLE_OK;
|
|
#endif
|
|
|
|
#ifdef CL_THREAD_SAFE
|
|
pthread_mutex_lock(&init_mutex);
|
|
#endif
|
|
if(!initialised) {
|
|
if(curl_global_init(CURL_GLOBAL_ALL) != 0) {
|
|
#ifdef CL_THREAD_SAFE
|
|
pthread_mutex_unlock(&init_mutex);
|
|
#endif
|
|
return NULL;
|
|
}
|
|
initialised = 1;
|
|
}
|
|
#ifdef CL_THREAD_SAFE
|
|
pthread_mutex_unlock(&init_mutex);
|
|
#endif
|
|
|
|
/* easy isn't the word I'd use... */
|
|
curl = curl_easy_init();
|
|
if(curl == NULL)
|
|
return NULL;
|
|
|
|
(void)curl_easy_setopt(curl, CURLOPT_USERAGENT, "www.clamav.net");
|
|
|
|
if(curl_easy_setopt(curl, CURLOPT_URL, url) != 0)
|
|
return NULL;
|
|
|
|
snprintf(fout, NAME_MAX, "%s/%s", dir, filename);
|
|
|
|
fp = fopen(fout, "wb");
|
|
|
|
if(fp == NULL) {
|
|
cli_errmsg("Can't open '%s' for writing", fout);
|
|
curl_easy_cleanup(curl);
|
|
return NULL;
|
|
}
|
|
#ifdef CURLOPT_WRITEDATA
|
|
if(curl_easy_setopt(curl, CURLOPT_WRITEDATA, fp) != 0) {
|
|
fclose(fp);
|
|
curl_easy_cleanup(curl);
|
|
return NULL;
|
|
}
|
|
#else
|
|
if(curl_easy_setopt(curl, CURLOPT_FILE, fp) != 0) {
|
|
fclose(fp);
|
|
curl_easy_cleanup(curl);
|
|
return NULL;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* If an item is in squid's cache get it from there (TCP_HIT/200)
|
|
* by default curl doesn't (TCP_CLIENT_REFRESH_MISS/200)
|
|
*/
|
|
headers = curl_slist_append(NULL, "Pragma:");
|
|
curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
|
|
|
|
/* These should be customisable */
|
|
curl_easy_setopt(curl, CURLOPT_TIMEOUT, 30);
|
|
curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT, 10);
|
|
#ifdef CURLOPT_MAXFILESIZE
|
|
curl_easy_setopt(curl, CURLOPT_MAXFILESIZE, 50*1024);
|
|
#endif
|
|
|
|
#ifdef CL_THREAD_SAFE
|
|
#ifdef CURLOPT_DNS_USE_GLOBAL_CACHE
|
|
curl_easy_setopt(curl, CURLOPT_DNS_USE_GLOBAL_CACHE, 0);
|
|
#endif
|
|
#endif
|
|
|
|
/*
|
|
* Prevent password: prompting with older versions
|
|
* FIXME: a better username?
|
|
*/
|
|
curl_easy_setopt(curl, CURLOPT_USERPWD, "username:password");
|
|
|
|
/*
|
|
* FIXME: valgrind reports "pthread_mutex_unlock: mutex is not locked"
|
|
* from gethostbyaddr_r within this. It may be a bug in libcurl
|
|
* rather than this code, but I need to check, see Curl_resolv()
|
|
* If pushed really hard it will sometimes say
|
|
* Conditional jump or move depends on uninitialised value(s) and
|
|
* quit. But the program seems to work OK without valgrind...
|
|
* Perhaps Curl_resolv() isn't thread safe?
|
|
*
|
|
* I have seen segfaults in version 7.12.3. Version 7.14 seems OK.
|
|
*/
|
|
/*
|
|
* On some C libraries (notably with FC3, glibc-2.3.3-74) you get a
|
|
* memory leak * here in getaddrinfo(), see
|
|
* https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=139559
|
|
*/
|
|
#ifdef CURLOPT_ERRORBUFFER
|
|
curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errorbuffer);
|
|
|
|
if(curl_easy_perform(curl) != CURLE_OK)
|
|
cli_warnmsg("URL %s failed to download: %s\n", url, errorbuffer);
|
|
#elif (LIBCURL_VERSION_NUM >= 0x070C00)
|
|
if((res = curl_easy_perform(curl)) != CURLE_OK)
|
|
cli_warnmsg("URL %s failed to download: %s\n", url,
|
|
curl_easy_strerror(res));
|
|
#else
|
|
if(curl_easy_perform(curl) != CURLE_OK)
|
|
cli_warnmsg("URL %s failed to download\n", url);
|
|
#endif
|
|
|
|
fclose(fp);
|
|
curl_easy_cleanup(curl);
|
|
curl_slist_free_all(headers);
|
|
|
|
return NULL;
|
|
}
|
|
#endif
|
|
|
|
#else
|
|
static void
|
|
checkURLs(message *m, const char *dir)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
#ifdef HAVE_BACKTRACE
|
|
static void
|
|
sigsegv(int sig)
|
|
{
|
|
signal(SIGSEGV, SIG_DFL);
|
|
print_trace(1);
|
|
exit(SIGSEGV);
|
|
}
|
|
|
|
static void
|
|
print_trace(int use_syslog)
|
|
{
|
|
void *array[10];
|
|
size_t size;
|
|
char **strings;
|
|
size_t i;
|
|
pid_t pid = getpid();
|
|
|
|
size = backtrace(array, 10);
|
|
strings = backtrace_symbols(array, size);
|
|
|
|
if(use_syslog == 0)
|
|
cli_dbgmsg("Backtrace of pid %d:\n", pid);
|
|
else
|
|
syslog(LOG_ERR, "Backtrace of pid %d:", pid);
|
|
|
|
for(i = 0; i < size; i++)
|
|
if(use_syslog)
|
|
syslog(LOG_ERR, "bt[%u]: %s", i, strings[i]);
|
|
else
|
|
cli_dbgmsg("%s\n", strings[i]);
|
|
|
|
/* TODO: dump the current email */
|
|
|
|
free(strings);
|
|
}
|
|
#endif
|
|
|
|
static bool
|
|
usefulHeader(int commandNumber, const char *cmd)
|
|
{
|
|
switch(commandNumber) {
|
|
case CONTENT_TRANSFER_ENCODING:
|
|
case CONTENT_DISPOSITION:
|
|
case CONTENT_TYPE:
|
|
return TRUE;
|
|
default:
|
|
if(strcasecmp(cmd, "From") == 0)
|
|
return TRUE;
|
|
else if(strcasecmp(cmd, "Received") == 0)
|
|
return TRUE;
|
|
else if(strcasecmp(cmd, "De") == 0)
|
|
return TRUE;
|
|
}
|
|
|
|
return FALSE;
|
|
}
|
|
|
|
/*
|
|
* Like fgets but cope with end of line by "\n", "\r\n", "\n\r", "\r"
|
|
*/
|
|
static char *
|
|
getline_from_mbox(char *buffer, size_t len, FILE *fin)
|
|
{
|
|
char *ret;
|
|
|
|
if(feof(fin))
|
|
return NULL;
|
|
|
|
if((len == 0) || (buffer == NULL)) {
|
|
cli_errmsg("Invalid call to getline_from_mbox(). Report to bugs@clamav.net\n");
|
|
return NULL;
|
|
}
|
|
|
|
ret = buffer;
|
|
|
|
do {
|
|
int c = getc(fin);
|
|
|
|
if(ferror(fin))
|
|
return NULL;
|
|
|
|
switch(c) {
|
|
case '\n':
|
|
*buffer++ = '\n';
|
|
c = getc(fin);
|
|
if((c != '\r') && !feof(fin))
|
|
ungetc(c, fin);
|
|
break;
|
|
default:
|
|
*buffer++ = (char)c;
|
|
continue;
|
|
case EOF:
|
|
break;
|
|
case '\r':
|
|
*buffer++ = '\n';
|
|
c = getc(fin);
|
|
if((c != '\n') && !feof(fin))
|
|
ungetc(c, fin);
|
|
break;
|
|
}
|
|
break;
|
|
} while(--len > 1);
|
|
|
|
if(len == 0) {
|
|
/* the email probably breaks RFC821 */
|
|
cli_warnmsg("getline_from_mbox: buffer overflow stopped - line lost\n");
|
|
return NULL;
|
|
}
|
|
if(len == 1)
|
|
/* over flows will have appear on separate lines */
|
|
cli_dbgmsg("getline_from_mbox: buffer overflow stopped - line recovered\n");
|
|
*buffer = '\0';
|
|
|
|
return ret;
|
|
}
|
|
|