* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) Tom Kistner <tom@duncanthrax.net> 2004 */
-/* License: GPL */
+/* Copyright (c) Tom Kistner <tom@duncanthrax.net> 2004, 2015
+ * License: GPL
+ * Copyright (c) The Exim Maintainers 2016
+ */
#include "exim.h"
#ifdef WITH_CONTENT_SCAN /* entire file */
FILE *mime_stream = NULL;
uschar *mime_current_boundary = NULL;
+static mime_header mime_header_list[] = {
+ { US"content-type:", 13, &mime_content_type },
+ { US"content-disposition:", 20, &mime_content_disposition },
+ { US"content-transfer-encoding:", 26, &mime_content_transfer_encoding },
+ { US"content-id:", 11, &mime_content_id },
+ { US"content-description:", 20, &mime_content_description }
+};
+
+static int mime_header_list_size = nelem(mime_header_list);
+
+static mime_parameter mime_parameter_list[] = {
+ { US"name=", 5, &mime_filename },
+ { US"filename=", 9, &mime_filename },
+ { US"charset=", 8, &mime_charset },
+ { US"boundary=", 9, &mime_boundary }
+};
+
+
/*************************************************
* set MIME anomaly level + text *
*************************************************/
/* Small wrapper to set the two expandables which
give info on detected "problems" in MIME
- encodings. Those are defined in mime.h. */
+ encodings. Indexes are defined in mime.h. */
-static void
-mime_set_anomaly(int level, const char *text)
+void
+mime_set_anomaly(int idx)
{
- mime_anomaly_level = level;
- mime_anomaly_text = CUS text;
+struct anom {
+ int level;
+ const uschar * text;
+} anom[] = { {1, CUS"Broken Quoted-Printable encoding detected"},
+ {2, CUS"Broken BASE64 encoding detected"} };
+
+mime_anomaly_level = anom[idx].level;
+mime_anomaly_text = anom[idx].text;
}
}
-/* decode base64 MIME part */
-static ssize_t
-mime_decode_base64(FILE* in, FILE* out, uschar* boundary)
-{
- uschar ibuf[MIME_MAX_LINE_LENGTH], obuf[MIME_MAX_LINE_LENGTH];
- uschar *ipos, *opos;
- ssize_t len, size = 0;
- int bytestate = 0;
-
- opos = obuf;
-
- while (Ufgets(ibuf, MIME_MAX_LINE_LENGTH, in) != NULL)
- {
- if (boundary != NULL
- && Ustrncmp(ibuf, "--", 2) == 0
- && Ustrncmp((ibuf+2), boundary, Ustrlen(boundary)) == 0
- )
- break;
-
- for (ipos = ibuf ; *ipos != '\r' && *ipos != '\n' && *ipos != 0; ++ipos)
- {
- if (*ipos == '=') /* skip padding */
- {
- ++bytestate;
- continue;
- }
- if (mime_b64[*ipos] == 128) /* skip bad characters */
- {
- mime_set_anomaly(MIME_ANOMALY_BROKEN_BASE64);
- continue;
- }
-
- /* simple state-machine */
- switch((bytestate++) & 3)
- {
- case 0:
- *opos = mime_b64[*ipos] << 2;
- break;
- case 1:
- *opos |= mime_b64[*ipos] >> 4;
- ++opos;
- *opos = mime_b64[*ipos] << 4;
- break;
- case 2:
- *opos |= mime_b64[*ipos] >> 2;
- ++opos;
- *opos = mime_b64[*ipos] << 6;
- break;
- case 3:
- *opos |= mime_b64[*ipos];
- ++opos;
- break;
- } /* switch */
- } /* for */
-
- /* something to write? */
- len = opos - obuf;
- if (len > 0)
- {
- if (fwrite(obuf, 1, len, out) != len) return -1; /* error */
- size += len;
- /* copy incomplete last byte to start of obuf, where we continue */
- if ((bytestate & 3) != 0)
- *obuf = *opos;
- opos = obuf;
- }
- } /* while */
-
- /* write out last byte if it was incomplete */
- if (bytestate & 3)
- {
- if (fwrite(obuf, 1, 1, out) != 1) return -1;
- ++size;
- }
-
- return size;
-}
-
/* decode quoted-printable MIME part */
static ssize_t
}
+/*
+ * Return open filehandle for combo of path and file.
+ * Side-effect: set mime_decoded_filename, to copy in allocated mem
+ */
static FILE *
mime_get_decode_file(uschar *pname, uschar *fname)
{
-FILE *f = NULL;
-uschar *filename;
-
-filename = (uschar *)malloc(2048);
-
if (pname && fname)
- {
- (void)string_format(filename, 2048, "%s/%s", pname, fname);
- f = modefopen(filename,"wb+",SPOOL_MODE);
- }
+ mime_decoded_filename = string_sprintf("%s/%s", pname, fname);
else if (!pname)
- f = modefopen(fname,"wb+",SPOOL_MODE);
+ mime_decoded_filename = string_copy(fname);
else if (!fname)
{
int file_nr = 0;
do
{
struct stat mystat;
- (void)string_format(filename, 2048,
- "%s/%s-%05u", pname, message_id, file_nr++);
+ mime_decoded_filename = string_sprintf("%s/%s-%05u", pname, message_id, file_nr++);
/* security break */
if (file_nr >= 1024)
break;
- result = stat(CS filename, &mystat);
+ result = stat(CS mime_decoded_filename, &mystat);
} while(result != -1);
-
- f = modefopen(filename, "wb+", SPOOL_MODE);
}
-/* set expansion variable */
-mime_decoded_filename = filename;
-
-return f;
+return modefopen(mime_decoded_filename, "wb+", SPOOL_MODE);
}
size_counter = decode_function(mime_stream, decode_file, mime_current_boundary);
clearerr(mime_stream);
-fseek(mime_stream, f_pos, SEEK_SET);
+if (fseek(mime_stream, f_pos, SEEK_SET))
+ return DEFER;
if (fclose(decode_file) != 0 || size_counter < 0)
return DEFER;
{
s++; /* skip opening " */
while (*s && *s != '"') /* " protects ; */
- val = string_cat(val, &size, &ptr, s++, 1);
+ val = string_catn(val, &size, &ptr, s++, 1);
if (*s) s++; /* skip closing " */
}
else
- val = string_cat(val, &size, &ptr, s++, 1);
+ val = string_catn(val, &size, &ptr, s++, 1);
if (val) val[ptr] = '\0';
*sp = s;
return val;
}
+static uschar *
+rfc2231_to_2047(const uschar * fname, const uschar * charset, int * len)
+{
+int size = 0, ptr = 0;
+uschar * val = string_catn(NULL, &size, &ptr, US"=?", 2);
+uschar c;
+
+if (charset)
+ val = string_cat(val, &size, &ptr, charset);
+val = string_catn(val, &size, &ptr, US"?Q?", 3);
+
+while ((c = *fname))
+ if (c == '%' && isxdigit(fname[1]) && isxdigit(fname[2]))
+ {
+ val = string_catn(val, &size, &ptr, US"=", 1);
+ val = string_catn(val, &size, &ptr, ++fname, 2);
+ fname += 2;
+ }
+ else
+ val = string_catn(val, &size, &ptr, fname++, 1);
+
+val = string_catn(val, &size, &ptr, US"?=", 2);
+val[*len = ptr] = '\0';
+return val;
+}
+
+
int
mime_acl_check(uschar *acl, FILE *f, struct mime_boundary_context *context,
uschar **user_msgptr, uschar **log_msgptr)
if (!fgets(CS header, MIME_MAX_HEADER_SIZE, f))
{
/* Hit EOF or read error. Ugh. */
- DEBUG(D_acl) debug_printf("Hit EOF ...\n");
+ DEBUG(D_acl) debug_printf("MIME: Hit EOF ...\n");
return rc;
}
if (Ustrncmp((header+2+Ustrlen(context->boundary)), "--", 2) == 0)
{
/* END boundary found */
- DEBUG(D_acl) debug_printf("End boundary found %s\n",
+ DEBUG(D_acl) debug_printf("MIME: End boundary found %s\n",
context->boundary);
return rc;
}
- DEBUG(D_acl) debug_printf("Next part with boundary %s\n",
+ DEBUG(D_acl) debug_printf("MIME: Next part with boundary %s\n",
context->boundary);
break;
}
mh < mime_header_list + mime_header_list_size;
mh++) if (strncmpic(mh->name, header, mh->namelen) == 0)
{
- uschar * header_value = NULL;
- int header_value_len = 0;
uschar * p = header + mh->namelen;
uschar * q;
for (q = p; *q != ';' && *q; q++) ;
*mh->value = string_copynlc(p, q-p);
- DEBUG(D_acl) debug_printf("found %s MIME header, value is '%s'\n",
+ DEBUG(D_acl) debug_printf("MIME: found %s header, value is '%s'\n",
mh->name, *mh->value);
if (*(p = q)) p++; /* jump past the ; */
{
mime_parameter * mp;
- DEBUG(D_acl) debug_printf(" considering paramlist '%s'\n", p);
+ DEBUG(D_acl) debug_printf("MIME: considering paramlist '%s'\n", p);
if ( !mime_filename
- && strncmpic("content-disposition:", header, 20) == 0
- && strncmpic("filename*", p, 9) == 0
+ && strncmpic(CUS"content-disposition:", header, 20) == 0
+ && strncmpic(CUS"filename*", p, 9) == 0
)
{ /* RFC 2231 filename */
uschar * q;
uschar * s = q;
/* look for a ' in the "filename" */
- while(*s != '\'' && *s) s++; /* s is ' or NUL */
+ while(*s != '\'' && *s) s++; /* s is 1st ' or NUL */
if ((size = s-q) > 0)
- {
mime_filename_charset = string_copyn(q, size);
- p = s;
- while(*p == '\'' && *p) p++; /* p is after ' */
- }
+ if (*(p = s)) p++;
+ while(*p == '\'') p++; /* p is after 2nd ' */
}
else
p = q;
- temp_string = expand_string(string_sprintf(
- "=?%s?Q?${sg{%s}{\\N%%([\\dA-Fa-f]{2})\\N}{=\\$1}}?=",
- mime_filename_charset, p));
- slen = Ustrlen(temp_string);
+ DEBUG(D_acl) debug_printf("MIME: charset %s fname '%s'\n",
+ mime_filename_charset ? mime_filename_charset : US"<NULL>", p);
+
+ temp_string = rfc2231_to_2047(p, mime_filename_charset, &slen);
+ DEBUG(D_acl) debug_printf("MIME: 2047-name %s\n", temp_string);
- temp_string = rfc2047_decode(temp_string, FALSE, NULL, 32,
+ temp_string = rfc2047_decode(temp_string, FALSE, NULL, ' ',
NULL, &err_msg);
+ DEBUG(D_acl) debug_printf("MIME: plain-name %s\n", temp_string);
+
size = Ustrlen(temp_string);
if (size == slen)
&dummy_errstr)
: NULL;
DEBUG(D_acl) debug_printf(
- " found %s MIME parameter in %s header, value '%s'\n",
+ "MIME: found %s parameter in %s header, value '%s'\n",
mp->name, mh->name, *mp->value);
break; /* done matching param names */
if (*p) p++;
} /* param scan on line */
- if (strncmpic("content-disposition:", header, 20) == 0)
+ if (strncmpic(CUS"content-disposition:", header, 20) == 0)
{
if (decoding_failed) mime_filename = mime_fname_rfc2231;
DEBUG(D_acl) debug_printf(
- " found %s MIME parameter in %s header, value is '%s'\n",
+ "MIME: found %s parameter in %s header, value is '%s'\n",
"filename", mh->name, mime_filename);
}
}
(nested_context.boundary != NULL) &&
(Ustrncmp(mime_content_type,"multipart",9) == 0) )
{
- DEBUG(D_acl) debug_printf("Entering multipart recursion, boundary '%s'\n",
- nested_context.boundary);
+ DEBUG(D_acl)
+ debug_printf("MIME: Entering multipart recursion, boundary '%s'\n",
+ nested_context.boundary);
nested_context.context =
context && context->context == MBC_ATTACHMENT
if (!mime_decoded_filename) /* decoding failed */
{
log_write(0, LOG_MAIN,
- "mime_regex acl condition warning - could not decode RFC822 MIME part to file.");
+ "MIME acl condition warning - could not decode RFC822 MIME part to file.");
rc = DEFER;
goto out;
}
projects / exim.git / blobdiff