/*
* Copyright (C) 2002 Nigel Horne <njh@bandsman.co.uk>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Change History:
* $Log: mbox.c,v $
* Revision 1.24 2003/12/20 13:55:36 nigelhorne
* Ensure multipart just save the bodies of attachments
*
* Revision 1.23 2003/12/14 18:07:01 nigelhorne
* Some viruses in embedded messages were not being found
*
* Revision 1.22 2003/12/13 16:42:23 nigelhorne
* call new cli_chomp
*
* Revision 1.21 2003/12/11 14:35:48 nigelhorne
* Better handling of encapsulated messages
*
* Revision 1.20 2003/12/06 04:03:26 nigelhorne
* Handle hand crafted emails that incorrectly set multipart headers
*
* Revision 1.19 2003/11/21 07:26:31 nigelhorne
* Scan multipart alternatives that have no boundaries, finds some uuencoded happy99
*
* Revision 1.18 2003/11/17 08:13:21 nigelhorne
* Handle spaces at the end of lines of MIME headers
*
* Revision 1.17 2003/11/06 05:06:42 nigelhorne
* Some applications weren't being scanned
*
* Revision 1.16 2003/11/04 08:24:00 nigelhorne
* Handle multipart messages that have no text portion
*
* Revision 1.15 2003/10/12 20:13:49 nigelhorne
* Use NO_STRTOK_R consistent with message.c
*
* Revision 1.14 2003/10/12 12:37:11 nigelhorne
* Appledouble encoded EICAR now found
*
* Revision 1.13 2003/10/01 09:27:42 nigelhorne
* Handle content-type header going over to a new line
*
* Revision 1.12 2003/09/29 17:10:19 nigelhorne
* Moved stub from heap to stack since its maximum size is known
*
* Revision 1.11 2003/09/29 12:58:32 nigelhorne
* Handle Content-Type: /; name="eicar.com"
*
* Revision 1.10 2003/09/28 10:06:34 nigelhorne
* Compilable under SCO; removed duplicate code with message.c
*
*/
static char const rcsid[] = "$Id: mbox.c,v 1.24 2003/12/20 13:55:36 nigelhorne Exp $";
#ifndef CL_DEBUG
/*#define NDEBUG /* map CLAMAV debug onto standard */
#endif
#ifdef CL_THREAD_SAFE
#ifndef _REENTRANT
#define _REENTRANT /* for Solaris 2.8 */
#endif
#endif
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <assert.h>
#include <string.h>
#include <strings.h>
#include <ctype.h>
#include <time.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/param.h>
#include <clamav.h>
#include "table.h"
#include "mbox.h"
#include "blob.h"
#include "text.h"
#include "message.h"
#include "others.h"
#include "defaults.h"
#include "str.h"
#if defined(NO_STRTOK_R) || !defined(CL_THREAD_SAFE)
#undef strtok_r
#undef __strtok_r
#define strtok_r(a,b,c) strtok(a,b)
#endif
/* required for AIX and Tru64 */
#ifdef TRUE
#undef TRUE
#endif
#ifdef FALSE
#undef FALSE
#endif
typedef enum { FALSE = 0, TRUE = 1 } bool;
static message *parseEmailHeaders(const message *m, const table_t *rfc821Table);
static int parseEmailBody(message *mainMessage, blob **blobsIn, int nBlobs, text *textIn, const char *dir, table_t *rfc821Table, table_t *subtypeTable);
static int boundaryStart(const char *line, const char *boundary);
static int endOfMessage(const char *line, const char *boundary);
static int initialiseTables(table_t **rfc821Table, table_t **subtypeTable);
static int getTextPart(message *const messages[], size_t size);
static size_t strip(char *buf, int len);
static size_t strstrip(char *s);
static bool continuationMarker(const char *line);
static int parseMimeHeader(message *m, const char *cmd, const table_t *rfc821Table, const char *arg);
static bool saveFile(const blob *b, const char *dir);
/* Maximum number of attachements that we accept */
#define MAX_ATTACHMENTS 10
/* Maximum line length according to RFC821 */
#define LINE_LENGTH 1000
/* Hashcodes for our hash tables */
#define CONTENT_TYPE 1
#define CONTENT_TRANSFER_ENCODING 2
#define CONTENT_DISPOSITION 3
/* Mime sub types */
#define PLAIN 1
#define ENRICHED 2
#define HTML 3
#define RICHTEXT 4
#define MIXED 5
#define ALTERNATIVE 6
#define DIGEST 7
#define SIGNED 8
#define PARALLEL 9
#define RELATED 10 /* RFC2387 */
#define REPORT 11 /* RFC1892 */
#define APPLEDOUBLE 12 /* Handling of this in only noddy for now */
static const struct tableinit {
const char *key;
int value;
} rfc821headers[] = {
{ "Content-Type:", CONTENT_TYPE },
{ "Content-Transfer-Encoding:", CONTENT_TRANSFER_ENCODING },
{ "Content-Disposition:", CONTENT_DISPOSITION },
{ NULL, 0 }
}, mimeSubtypes[] = {
/* subtypes of Text */
{ "plain", PLAIN },
{ "enriched", ENRICHED },
{ "html", HTML },
{ "richtext", RICHTEXT },
/* subtypes of Multipart */
{ "mixed", MIXED },
{ "alternative", ALTERNATIVE },
{ "digest", DIGEST },
{ "signed", SIGNED },
{ "parallel", PARALLEL },
{ "related", RELATED },
{ "report", REPORT },
{ "appledouble", APPLEDOUBLE },
{ NULL, 0 }
};
/* Maximum filenames under various systems */
#ifndef NAME_MAX /* e.g. Linux */
#ifdef MAXNAMELEN /* e.g. Solaris */
#define NAME_MAX MAXNAMELEN
#else
#ifdef FILENAME_MAX /* e.g. SCO */
#define NAME_MAX FILENAME_MAX
#endif
#endif
#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?
* TODO: if debug is enabled, catch a segfault and dump the current e-mail
* in it's entirety, then call abort()
* 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
*/
int
cl_mbox(const char *dir, int desc)
{
int retcode, i;
message *m, *body;
table_t *rfc821Table, *subtypeTable;
FILE *fd;
char buffer[LINE_LENGTH];
cli_dbgmsg("in mbox()\n");
i = dup(desc);
if((fd = fdopen(i, "rb")) == NULL) {
cli_errmsg("Can't open descriptor %d\n", desc);
close(i);
return -1;
}
if(fgets(buffer, sizeof(buffer), fd) == NULL) {
/* empty message */
fclose(fd);
return 0;
}
m = messageCreate();
assert(m != NULL);
if(initialiseTables(&rfc821Table, &subtypeTable) < 0) {
messageDestroy(m);
fclose(fd);
return -1;
}
/*
* is it a UNIX style mbox with more than one
* mail message, or just a single mail message?
*/
if(strncmp(buffer, "From ", 5) == 0) {
/*
* Have been asked to check a UNIX style mbox file, which
* may contain more than one e-mail message to decode
*/
bool lastLineWasEmpty = FALSE;
do {
/*cli_dbgmsg("read: %s", buffer);*/
cli_chomp(buffer);
if(lastLineWasEmpty && (strncmp(buffer, "From ", 5) == 0)) {
/*
* End of a message in the mail box
*/
body = parseEmailHeaders(m, rfc821Table);
messageDestroy(m);
messageClean(body);
if(messageGetBody(body))
if(!parseEmailBody(body, NULL, 0, NULL, dir, rfc821Table, subtypeTable))
break;
/*
* Starting a new message, throw away all the
* information about the old one
*/
m = body;
messageReset(body);
lastLineWasEmpty = TRUE;
cli_dbgmsg("Finished processing message\n");
} else
lastLineWasEmpty = (buffer[0] == '\0');
messageAddLine(m, buffer);
} while(fgets(buffer, sizeof(buffer), fd) != NULL);
} else
/*
* It's a single message, parse the headers then the body
*/
do {
cli_chomp(buffer);
messageAddLine(m, buffer);
} while(fgets(buffer, sizeof(buffer), fd) != NULL);
fclose(fd);
retcode = 0;
body = parseEmailHeaders(m, rfc821Table);
messageDestroy(m);
/*
* Write out the last entry in the mailbox
*/
messageClean(body);
if(messageGetBody(body))
if(!parseEmailBody(body, NULL, 0, NULL, dir, rfc821Table, subtypeTable))
retcode = -1;
/*
* Tidy up and quit
*/
messageDestroy(body);
tableDestroy(rfc821Table);
tableDestroy(subtypeTable);
cli_dbgmsg("cli_mbox returning %d\n", retcode);
return retcode;
}
/*
* The given message contains a raw e-mail.
*
* This function parses the headers of m and sets the message's arguments
*
* Returns the message's body with the correct arguments set
*/
static message *
parseEmailHeaders(const message *m, const table_t *rfc821Table)
{
bool inContinuationHeader = FALSE;
bool inHeader = TRUE;
text *t, *msgText;
message *ret;
if(m == NULL)
return NULL;
msgText = messageToText(m);
if(msgText == NULL)
return NULL;
t = msgText;
ret = messageCreate();
do {
char *buffer = strdup(t->t_text);
#ifdef CL_THREAD_SAFE
char *strptr;
#endif
cli_chomp(buffer);
/*
* Section B.2 of RFC822 says TAB or SPACE means
* a continuation of the previous entry.
*/
if(inHeader && ((buffer[0] == '\t') || (buffer[0] == ' ')))
inContinuationHeader = TRUE;
if(inContinuationHeader) {
const char *ptr;
if(!continuationMarker(buffer))
inContinuationHeader = FALSE; /* no more args */
/*
* Add all the arguments on the line
*/
for(ptr = strtok_r(buffer, ";", &strptr); ptr; ptr = strtok_r(NULL, ":", &strptr))
messageAddArgument(ret, ptr);
} else if(inHeader) {
cli_dbgmsg("Deal with header %s\n", buffer);
/*
* A blank line signifies the end of the header and
* the start of the text
*/
if(strstrip(buffer) == 0) {
cli_dbgmsg("End of header information\n");
inHeader = FALSE;
} else {
const bool isLastLine = !continuationMarker(buffer);
const char *cmd = strtok_r(buffer, " \t", &strptr);
if(cmd && *cmd) {
const char *arg = strtok_r(NULL, "", &strptr);
if(arg)
if(parseMimeHeader(ret, cmd, rfc821Table, arg) == CONTENT_TYPE)
inContinuationHeader = !isLastLine;
}
}
} else
messageAddLine(ret, buffer);
free(buffer);
} while((t = t->t_next) != NULL);
textDestroy(msgText);
return ret;
}
/*
* This is a recursive routine.
*
* 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
* blobsIn contains the array of attachments found so far
*
* Returns:
* 0 for fail
* 1 for success, attachements saved
* 2 for success, attachements not saved
*/
static int /* success or fail */
parseEmailBody(message *mainMessage, blob **blobsIn, int nBlobs, text *textIn, const char *dir, table_t *rfc821Table, table_t *subtypeTable)
{
char *ptr;
message *messages[MAXALTERNATIVE];
int inhead, inMimeHead, i, rc, htmltextPart, multiparts = 0;
text *aText;
blob *blobList[MAX_ATTACHMENTS], **blobs;
const char *cptr;
cli_dbgmsg("in parseEmailBody(nBlobs = %d)\n", nBlobs);
/* Pre-assertions */
if(nBlobs >= MAX_ATTACHMENTS) {
cli_warnmsg("Not all attachments will be scanned\n");
return 2;
}
aText = textIn;
blobs = blobsIn;
/* Anything left to be parsed? */
if(mainMessage && (messageGetBody(mainMessage) != NULL)) {
int numberOfAttachments = 0;
mime_type mimeType;
const char *mimeSubtype;
const text *t_line;
/*bool isAlternative;*/
const char *boundary;
message *aMessage;
#ifdef CL_THREAD_SAFE
char *strptr;
#endif
cli_dbgmsg("Parsing mail file\n");
mimeType = messageGetMimeType(mainMessage);
mimeSubtype = messageGetMimeSubtype(mainMessage);
if((mimeType == TEXT) && (tableFind(subtypeTable, mimeSubtype) == 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;
}
cli_dbgmsg("mimeType = %d\n", mimeType);
switch(mimeType) {
case NOMIME:
aText = textAddMessage(aText, mainMessage);
break;
case TEXT:
if(tableFind(subtypeTable, mimeSubtype) == PLAIN)
aText = textCopy(messageGetBody(mainMessage));
break;
case MULTIPART:
assert(mimeSubtype[0] != '\0');
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;
}
/*
* Get to the start of the first message
*/
for(t_line = messageGetBody(mainMessage); t_line; t_line = t_line->t_next)
if(boundaryStart(t_line->t_text, boundary))
break;
if(t_line == NULL) {
cli_warnmsg("Multipart MIME message contains no parts\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 uuencoded 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;
/*
* This looks like parseEmailHeaders() - maybe there's
* some duplication of code to be cleaned up
*/
for(multiparts = 0; t_line && (multiparts < MAXALTERNATIVE); multiparts++) {
aMessage = messages[multiparts] = messageCreate();
cli_dbgmsg("Now read in part %d\n", multiparts);
/* tk: shut up parentheses warning */
while((t_line = t_line->t_next)) {
const char *line = t_line->t_text;
/*cli_dbgmsg("inMimeHead %d inhead %d boundary %s line '%s' next '%s'\n",
inMimeHead, inhead, boundary, line, t_line->t_next ? t_line->t_next->t_text : "(null)");*/
if(inMimeHead) {
cli_dbgmsg("About to add mime Argument '%s'\n",
line);
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) {
char *copy, *arg;
if(strlen(line) == 0) {
inhead = 0;
continue;
}
/*
* Some clients are broken and
* put white space after the ;
*/
inMimeHead = continuationMarker(line);
if(!inMimeHead)
if(t_line->t_next && ((t_line->t_next->t_text[0] == '\t') || (t_line->t_next->t_text[0] == ' ')))
inMimeHead = TRUE;
copy = strdup(line);
ptr = strtok_r(copy, " \t", &strptr);
switch(tableFind(rfc821Table, ptr)) {
case CONTENT_TYPE:
cli_dbgmsg("insert content-type: parse line '%s'\n", line);
arg = strtok_r(NULL, "\r\n", &strptr);
if((arg == NULL) || (strchr(arg, '/') == NULL)) {
if(arg == NULL)
cli_warnmsg("Empty content-type received, assuming text/plain; charset=us-ascii\n", arg);
else
cli_warnmsg("Invalid content-type '%s' received, no subtype specified, assuming text/plain; charset=us-ascii\n", arg);
messageSetMimeType(aMessage, "text");
messageSetMimeSubtype(aMessage, "plain");
} else {
if(*arg == '/') {
cli_warnmsg("Content-type '/' received, assuming application/octet-stream\n");
messageSetMimeType(aMessage, "application");
messageSetMimeSubtype(aMessage, "octet-stream");
ptr = strtok_r(arg, ";", &strptr);
} else {
messageSetMimeType(aMessage, strtok_r(arg, "/", &strptr));
messageSetMimeSubtype(aMessage, strtok_r(NULL, ";", &strptr));
}
if((ptr = strtok_r(NULL, "\r\n", &strptr)) != NULL)
messageAddArguments(aMessage, ptr);
}
break;
case CONTENT_TRANSFER_ENCODING:
ptr = strtok_r(NULL, "", &strptr);
if(ptr) {
messageSetEncoding(aMessage, ptr);
break;
}
/*
* Encoding type not found
*/
if(!inMimeHead) {
cli_warnmsg("Empty encoding type, assuming none");
messageSetEncoding(aMessage, "7bit");
break;
}
/*
* Handle the case
* when it flows over
* to the next line.
*
* Content-type:
* quoted-printable
*/
if(t_line->t_next) {
t_line = t_line->t_next;
messageSetEncoding(aMessage, t_line->t_text);
break;
}
cli_warnmsg("Empty encoding type, assuming none");
messageSetEncoding(aMessage, "7bit");
break;
case CONTENT_DISPOSITION:
messageSetDispositionType(aMessage, strtok_r(NULL, ";", &strptr));
messageAddArgument(aMessage, strtok_r(NULL, "", &strptr));
break;
}
free(copy);
} else if(boundaryStart(line, boundary)) {
inhead = 1;
break;
} 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
messageAddLine(aMessage, line);
}
messageClean(aMessage);
}
free((char *)boundary);
if(multiparts == 0)
return 2; /* Nothing to do */
cli_dbgmsg("The message has %d parts\n", multiparts);
cli_dbgmsg("Find out the multipart type(%s)\n", mimeSubtype);
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");
rc = 0;
} else
rc = parseEmailBody(aMessage, blobs, nBlobs, aText, dir, rfc821Table, subtypeTable);
blobArrayDestroy(blobs, nBlobs);
blobs = NULL;
nBlobs = 0;
/*
* 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 ALTERNATIVE:
cli_dbgmsg("Multipart alternative handler\n");
htmltextPart = getTextPart(messages, multiparts);
if(htmltextPart == -1)
htmltextPart = 0;
aMessage = messages[htmltextPart];
aText = textAddMessage(aText, aMessage);
rc = parseEmailBody(NULL, blobs, nBlobs, aText, dir, rfc821Table, subtypeTable);
if(rc == 1) {
/*
* Alternative message has saved its
* attachments, ensure we don't do
* the same thing
*/
blobArrayDestroy(blobs, nBlobs);
blobs = NULL;
nBlobs = 0;
rc = 2;
}
/*
* Fall through - some clients are broken and
* say alternative instead of mixed. The Klez
* virus is broken that way
*/
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)
mainMessage = NULL;
cli_dbgmsg("Mixed message with %d parts\n", multiparts);
for(i = 0; i < multiparts; i++) {
bool addAttachment = FALSE;
bool addToText = FALSE;
const char *dtype;
text *t;
message *body;
aMessage = messages[i];
assert(aMessage != NULL);
dtype = messageGetDispositionType(aMessage);
cptr = messageGetMimeSubtype(aMessage);
cli_dbgmsg("Mixed message part %d is of type %d\n",
i, messageGetMimeType(aMessage));
switch(messageGetMimeType(aMessage)) {
case APPLICATION:
#if 0
/* strict checking... */
if((strcasecmp(dtype, "attachment") == 0) ||
(strcasecmp(cptr, "x-msdownload") == 0) ||
(strcasecmp(cptr, "octet-stream") == 0) ||
(strcasecmp(dtype, "octet-stream") == 0))
addAttachment = TRUE;
else {
cli_dbgmsg("Discarded mixed/application not sent as attachment\n");
continue;
}
#endif
addAttachment = TRUE;
break;
case NOMIME:
mainMessage = NULL;
addToText = TRUE;
if(messageGetBody(aMessage) == NULL)
/*
* No plain text version
*/
messageAddLine(aMessage, "No plain text alternative");
assert(messageGetBody(aMessage) != NULL);
break;
case TEXT:
if(strcasecmp(dtype, "attachment") == 0)
addAttachment = TRUE;
else if((*dtype == '\0') || (strcasecmp(dtype, "inline") == 0)) {
mainMessage = NULL;
/*
* Strictly speaking
* a text/html part is
* not an attachment. We
* pretend it is so that
* we can decode and
* scan it
*/
if(strcasecmp(messageGetMimeSubtype(aMessage), "plain") == 0)
addToText = TRUE;
else {
messageAddArgument(aMessage, "filename=textportion");
addAttachment = TRUE;
}
} else {
cli_dbgmsg("Text type %s is not supported", dtype);
continue;
}
break;
case MESSAGE:
cli_dbgmsg("Found message inside multipart\n");
body = parseEmailHeaders(aMessage, rfc821Table);
if(body) {
rc = parseEmailBody(body, blobs, nBlobs, NULL, dir, rfc821Table, subtypeTable);
messageDestroy(body);
}
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) {
body = parseEmailHeaders(aMessage, rfc821Table);
if(body) {
t = messageToText(body);
rc = parseEmailBody(body, blobs, nBlobs, t, dir, rfc821Table, subtypeTable);
textDestroy(t);
mainMessage = body;
}
} else {
rc = parseEmailBody(NULL, blobs, nBlobs, NULL, dir, rfc821Table, subtypeTable);
mainMessage = NULL;
}
continue;
case AUDIO:
case IMAGE:
/*
* TODO: it may be nice to
* have an option to throw
* away all images and sound
* files for ultra-secure sites
*/
addAttachment = TRUE;
break;
default:
cli_dbgmsg("Only text and application attachments are supported, type = %d\n",
messageGetMimeType(aMessage));
continue;
}
/*
* It must be either text or
* an attachment. It can't be both
*/
assert(addToText || addAttachment);
assert(!(addToText && addAttachment));
if(addToText)
aText = textAdd(aText, messageGetBody(aMessage));
else if(addAttachment) {
blob *aBlob = messageToBlob(aMessage);
if(aBlob) {
assert(blobGetFilename(aBlob) != NULL);
/*if(blobGetDataSize(aBlob) > 0)*/
blobList[numberOfAttachments++] = aBlob;
}
}
}
if(numberOfAttachments == 0) {
/* No usable attachment was found */
rc = parseEmailBody(NULL, NULL, 0, aText, dir, rfc821Table, subtypeTable);
break;
}
/*
* Store any existing attachments at the end of
* the list we've just built up
*/
for(i = 0; i < nBlobs; i++) {
#ifdef CL_DEBUG
assert(blobs[i]->magic == BLOB);
#endif
blobList[numberOfAttachments++] = blobs[i];
}
rc = parseEmailBody(mainMessage, blobList, numberOfAttachments, aText, dir, rfc821Table, subtypeTable);
break;
case DIGEST:
/*
* TODO:
* According to section 5.1.5 RFC2046, the
* default mime type of multipart/digest parts
* is message/rfc822
*/
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], blobs, nBlobs, aText, dir, rfc821Table, subtypeTable);
blobArrayDestroy(blobs, nBlobs);
blobs = NULL;
nBlobs = 0;
break;
default:
/*
* According to section 7.2.6 of RFC1521,
* unrecognised multiparts should be treated as
* multipart/mixed. I don't do this yet so
* that I can see what comes along...
*/
cli_warnmsg("Unsupported multipart format `%s'\n", mimeSubtype);
rc = 0;
}
for(i = 0; i < multiparts; i++)
messageDestroy(messages[i]);
if(blobs && (blobsIn == NULL))
puts("arraydestroy");
if(aText && (textIn == NULL))
textDestroy(aText);
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;
}
if((strcasecmp(mimeSubtype, "rfc822") == 0) ||
(strcasecmp(mimeSubtype, "delivery-status") == 0)) {
/*
* Found a message encapsulated within
* another message
*
* Thomas Lamy <Thomas.Lamy@in-online.net>:
* ensure t is correctly freed
*/
text *t, *msgText = messageToText(mainMessage);
message *m, *body;
t = msgText;
assert(t != NULL);
m = messageCreate();
assert(m != NULL);
cli_dbgmsg("Decode rfc822");
do {
char *buffer = strdup(t->t_text);
cli_chomp(buffer);
messageAddLine(m, buffer);
free(buffer);
} while((t = t->t_next) != NULL);
textDestroy(msgText);
body = parseEmailHeaders(m, rfc821Table);
messageDestroy(m);
m = body;
messageClean(m);
if(messageGetBody(m))
rc = parseEmailBody(m, NULL, 0, NULL, dir, rfc821Table, subtypeTable);
messageDestroy(m);
break;
} else if(strcasecmp(mimeSubtype, "partial") == 0)
/* TODO */
cli_warnmsg("Content-type message/partial not yet supported");
else if(strcasecmp(mimeSubtype, "external-body") == 0)
/*
* I don't believe that we should be going
* around the Internet looking for referenced
* files...
*/
cli_warnmsg("Attempt to send Content-type message/external-body trapped");
else
cli_warnmsg("Unsupported message format `%s'\n", mimeSubtype);
return 0;
case APPLICATION:
cptr = messageGetMimeSubtype(mainMessage);
/*if((strcasecmp(cptr, "octet-stream") == 0) ||
(strcasecmp(cptr, "x-msdownload") == 0)) {*/
{
blob *aBlob = messageToBlob(mainMessage);
if(aBlob) {
cli_dbgmsg("Saving main message as attachment %d\n", nBlobs);
assert(blobGetFilename(aBlob) != NULL);
/*
* It's likely that we won't have built
* a set of attachments
*/
if(blobs == NULL)
blobs = blobList;
for(i = 0; i < nBlobs; i++)
if(blobs[i] == NULL)
break;
blobs[i] = aBlob;
if(i == nBlobs) {
nBlobs++;
assert(nBlobs < MAX_ATTACHMENTS);
}
}
} /*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;
}
}
cli_dbgmsg("%d attachments found\n", nBlobs);
rc = 1;
if(nBlobs == 0) {
blob *b;
/*
* 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++) {
b = messageToBlob(messages[i]);
assert(b != NULL);
cli_dbgmsg("Saving multipart %d, encoded with scheme %d\n",
i, messageGetEncoding(messages[i]));
(void)saveFile(b, dir);
blobDestroy(b);
}
if(mainMessage) {
/*
* Look for uu-encoded main file
*/
const text *t_line = uuencodeBegin(mainMessage);
if(t_line != NULL) {
cli_dbgmsg("Found uuencoded file\n");
/*
* Main part contains uuencoded section
*/
messageSetEncoding(mainMessage, "x-uuencode");
if((b = messageToBlob(mainMessage)) != NULL) {
if((cptr = blobGetFilename(b)) != NULL) {
cli_dbgmsg("Found uuencoded message %s\n", cptr);
(void)saveFile(b, dir);
}
blobDestroy(b);
}
} else {
cli_dbgmsg("Not found uuencoded file\n");
messageAddArgument(mainMessage, "filename=textportion");
if((b = messageToBlob(mainMessage)) != NULL) {
/*
* Save main part to scan that
*/
cli_dbgmsg("Saving main message, encoded with scheme %d\n",
messageGetEncoding(mainMessage));
(void)saveFile(b, dir);
blobDestroy(b);
}
}
} else
rc = (multiparts) ? 1 : 2; /* anything saved? */
} else {
short attachmentNumber;
for(attachmentNumber = 0; attachmentNumber < nBlobs; attachmentNumber++) {
blob *b = blobs[attachmentNumber];
if(b) {
if(!saveFile(b, dir))
break;
blobDestroy(b);
blobs[attachmentNumber] = NULL;
}
}
}
if(aText && (textIn == NULL))
textDestroy(aText);
/* Already done */
if(blobs && (blobsIn == NULL))
blobArrayDestroy(blobs, nBlobs);
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)
{
/*
* Gibe.B3 is broken it has:
* boundary="---- =_NextPart_000_01C31177.9DC7C000"
* but it's boundaries look like
* ------ =_NextPart_000_01C31177.9DC7C000
* notice the extra '-'
*/
if(strstr(line, boundary) != NULL) {
cli_dbgmsg("found %s in %s\n", boundary, line);
return 1;
}
if(*line++ != '-')
return 0;
if(*line++ != '-')
return 0;
return strcasecmp(line, boundary) == 0;
}
/*
* 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++ != '-')
return 0;
if(*line++ != '-')
return 0;
len = strlen(boundary);
if(strncasecmp(line, boundary, len) != 0)
return 0;
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)
return -1;
*subtypeTable = tableCreate();
assert(*subtypeTable != NULL);
for(tableinit = mimeSubtypes; tableinit->key; tableinit++)
if(tableInsert(*subtypeTable, tableinit->key, tableinit->value) < 0) {
tableDestroy(*rfc821Table);
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;
for(i = 0; i < size; i++) {
assert(messages[i] != NULL);
if((messageGetMimeType(messages[i]) == TEXT) &&
(strcasecmp(messageGetMimeSubtype(messages[i]), "html") == 0))
return (int)i;
}
for(i = 0; i < size; i++)
if(messageGetMimeType(messages[i]) == TEXT)
return (int)i;
return -1;
}
/*
* strip -
* Remove the trailing spaces from a buffer
* 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
*/
static size_t
strstrip(char *s)
{
if(s == (char *)NULL)
return(0);
return(strip(s, strlen(s) + 1));
}
/*
* When parsing a MIME header see if this spans more than one line. A
* semi-colon at the end of the line indicates that the MIME information
* is continued on the next line.
*
* Some clients are broken and put white space after the ;
*/
static bool
continuationMarker(const char *line)
{
const char *ptr;
assert(line != NULL);
#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)
{
int type = tableFind(rfc821Table, cmd);
#ifdef CL_THREAD_SAFE
char *strptr;
#endif
char *copy = strdup(arg);
char *ptr = copy;
cli_dbgmsg("parseMimeHeader: cmd='%s', arg='%s'\n", cmd, arg);
strstrip(copy);
switch(type) {
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)
cli_warnmsg("Empty content-type received, no subtype specified, assuming text/plain; charset=us-ascii\n");
else if(strchr(copy, '/') == NULL)
cli_warnmsg("Invalid content-type '%s' received, no subtype specified, assuming text/plain; charset=us-ascii\n", copy);
else {
char *s;
/*
* Some clients are broken and
* put white space after the ;
*/
strstrip(copy);
messageSetMimeType(m, strtok_r(copy, "/", &strptr));
/*
* Stephen White <stephen@earth.li>
* Some clients put space after
* the mime type but before
* the ;
*/
s = strtok_r(NULL, ";", &strptr);
strstrip(s);
messageSetMimeSubtype(m, s);
/*
* Add in all the arguments.
*/
while((copy = strtok_r(NULL, "\r\n \t", &strptr)))
messageAddArgument(m, copy);
}
break;
case CONTENT_TRANSFER_ENCODING:
messageSetEncoding(m, copy);
break;
case CONTENT_DISPOSITION:
messageSetDispositionType(m, strtok_r(copy, ";", &strptr));
messageAddArgument(m, strtok_r(NULL, "\r\n", &strptr));
}
free(ptr);
return type;
}
/*
* Save some data as a unique file in the given directory.
*/
static bool
saveFile(const blob *b, const char *dir)
{
unsigned long nbytes = blobGetDataSize(b);
size_t len = 0;
int fd;
const char *cptr, *suffix;
char filename[NAME_MAX + 1];
assert(dir != NULL);
if(nbytes == 0)
return TRUE;
cptr = blobGetFilename(b);
if(cptr == NULL) {
cptr = "unknown";
suffix = "";
} else {
/*
* Some programs are broken and use an idea of a ".suffix"
* to determine the file type rather than looking up the
* magic number. CPM has a lot to answer for...
* FIXME: the suffix now appears twice in the filename...
*/
suffix = strrchr(cptr, '.');
if(suffix == NULL)
suffix = "";
else
len = strlen(suffix);
}
cli_dbgmsg("Saving attachment in %s/%s\n", dir, cptr);
/*
* Allow for very long filenames. We have to truncate them to fit
*/
snprintf(filename, sizeof(filename) - 1 - len, "%s/%.*sXXXXXX", dir,
(int)(sizeof(filename) - 9 - len - strlen(dir)), cptr);
/*
* TODO: add a HAVE_MKSTEMP property
*/
#if defined(C_LINUX) || defined(C_BSD) || defined(HAVE_MKSTEMP)
fd = mkstemp(filename);
#else
(void)mktemp(filename);
fd = open(filename, O_WRONLY|O_CREAT|O_EXCL|O_TRUNC, 0600);
#endif
if(fd < 0) {
cli_errmsg("Can't create temporary file %s: %s\n", filename, strerror(errno));
return FALSE;
}
/*
* Add the suffix back to the end of the filename. Tut-tut, filenames
* should be independant of their usage on UNIX type systems.
*/
if(len > 1) {
char stub[NAME_MAX + 1];
snprintf(stub, sizeof(stub), "%s%s", filename, suffix);
#ifdef C_LINUX
rename(stub, filename);
#else
link(stub, filename);
unlink(stub);
#endif
}
write(fd, blobGetData(b), (size_t)nbytes);
cli_dbgmsg("Attachment saved as %s (%lu bytes long)\n",
filename, nbytes);
return (close(fd) >= 0);
}