nm4 2009/11/06 13:29:47 GMT
Modified files:
exim-doc/doc-txt ChangeLog
exim-src/src mime.c
Log:
Base64 decode bug fixes. Fixes: #39
Revision Changes Path
1.588 +3 -0 exim/exim-doc/doc-txt/ChangeLog
1.16 +147 -151 exim/exim-src/src/mime.c
Index: ChangeLog
===================================================================
RCS file: /home/cvs/exim/exim-doc/doc-txt/ChangeLog,v
retrieving revision 1.587
retrieving revision 1.588
diff -u -r1.587 -r1.588
--- ChangeLog 5 Nov 2009 19:40:51 -0000 1.587
+++ ChangeLog 6 Nov 2009 13:29:47 -0000 1.588
@@ -1,4 +1,4 @@
-$Cambridge: exim/exim-doc/doc-txt/ChangeLog,v 1.587 2009/11/05 19:40:51 nm4 Exp $
+$Cambridge: exim/exim-doc/doc-txt/ChangeLog,v 1.588 2009/11/06 13:29:47 nm4 Exp $
Change log file for Exim from version 4.21
-------------------------------------------
@@ -148,6 +148,9 @@
NM/34 Bugzilla 901: Fix sign/unsigned and UTF mistmatches
Patch by Serge Demonchaux
+NM/35 Bugzilla 39: Base64 decode bug fixes
+ Patch by Jakob Hirsch
+
Exim version 4.69
-----------------
Index: mime.c
===================================================================
RCS file: /home/cvs/exim/exim-src/src/mime.c,v
retrieving revision 1.15
retrieving revision 1.16
diff -u -r1.15 -r1.16
--- mime.c 5 Sep 2006 15:34:41 -0000 1.15
+++ mime.c 6 Nov 2009 13:29:47 -0000 1.16
@@ -1,4 +1,4 @@
-/* $Cambridge: exim/exim-src/src/mime.c,v 1.15 2006/09/05 15:34:41 ph10 Exp $ */
+/* $Cambridge: exim/exim-src/src/mime.c,v 1.16 2009/11/06 13:29:47 nm4 Exp $ */
/*************************************************
* Exim - an Internet mail transport agent *
@@ -74,122 +74,156 @@
}
+/* just dump MIME part without any decoding */
+static int mime_decode_asis(FILE* in, FILE* out, uschar* boundary)
+{
+ int len, size = 0;
+ uschar buffer[MIME_MAX_LINE_LENGTH];
-uschar *mime_parse_line(uschar *buffer, uschar *data, uschar *encoding, int *num_decoded) {
+ while(fgets(CS buffer, MIME_MAX_LINE_LENGTH, mime_stream) != NULL) {
+ if (boundary != NULL
+ && Ustrncmp(buffer, "--", 2) == 0
+ && Ustrncmp((buffer+2), boundary, Ustrlen(boundary)) == 0
+ )
+ break;
+
+ len = Ustrlen(buffer);
+ if (fwrite(buffer, 1, (size_t)len, out) < len)
+ return -1;
+ size += len;
+ } /* while */
+ return size;
+}
- if (encoding == NULL) {
- /* no encoding type at all */
- NO_DECODING:
- memcpy(data, buffer, Ustrlen(buffer));
- data[(Ustrlen(buffer))] = 0;
- *num_decoded = Ustrlen(data);
- return data;
- }
- else if (Ustrcmp(encoding,"base64") == 0) {
- uschar *p = buffer;
- int offset = 0;
-
- /* ----- BASE64 ---------------------------------------------------- */
- /* NULL out '\r' and '\n' chars */
- while (Ustrrchr(p,'\r') != NULL) {
- *(Ustrrchr(p,'\r')) = '\0';
- };
- while (Ustrrchr(p,'\n') != NULL) {
- *(Ustrrchr(p,'\n')) = '\0';
- };
- while (*(p+offset) != '\0') {
- /* hit illegal char ? */
- if (mime_b64[*(p+offset)] == 128) {
+/* decode base64 MIME part */
+static int mime_decode_base64(FILE* in, FILE* out, uschar* boundary)
+{
+ uschar ibuf[MIME_MAX_LINE_LENGTH], obuf[MIME_MAX_LINE_LENGTH];
+ uschar *ipos, *opos;
+ size_t len, size = 0;
+ int bytestate = 0;
+
+ opos = obuf;
+
+ while (fgets(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) {
+ /* skip padding */
+ if (*ipos == '=') {
+ ++bytestate;
+ continue;
+ }
+ /* skip bad characters */
+ if (mime_b64[*ipos] == 128) {
mime_set_anomaly(MIME_ANOMALY_BROKEN_BASE64);
- offset++;
+ continue;
}
- else {
- *p = mime_b64[*(p+offset)];
- p++;
- };
- };
- *p = 255;
+ /* 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 */
- /* line is translated, start bit shifting */
- p = buffer;
- *num_decoded = 0;
- while(*p != 255) {
- uschar tmp_c;
+ /* write out last byte if it was incomplete */
+ if (bytestate & 3) {
+ if (fwrite(obuf, 1, 1, out) != 1)
+ return -1;
+ ++size;
+ }
- /* byte 0 ---------------------- */
- if (*(p+1) == 255) {
- break;
- }
- data[(*num_decoded)] = *p;
- data[(*num_decoded)] <<= 2;
- tmp_c = *(p+1);
- tmp_c >>= 4;
- data[(*num_decoded)] |= tmp_c;
- (*num_decoded)++;
- p++;
- /* byte 1 ---------------------- */
- if (*(p+1) == 255) {
- break;
- }
- data[(*num_decoded)] = *p;
- data[(*num_decoded)] <<= 4;
- tmp_c = *(p+1);
- tmp_c >>= 2;
- data[(*num_decoded)] |= tmp_c;
- (*num_decoded)++;
- p++;
- /* byte 2 ---------------------- */
- if (*(p+1) == 255) {
- break;
- }
- data[(*num_decoded)] = *p;
- data[(*num_decoded)] <<= 6;
- data[(*num_decoded)] |= *(p+1);
- (*num_decoded)++;
- p+=2;
+ return size;
+}
- };
- return data;
- /* ----------------------------------------------------------------- */
- }
- else if (Ustrcmp(encoding,"quoted-printable") == 0) {
- uschar *p = buffer;
- /* ----- QP -------------------------------------------------------- */
- *num_decoded = 0;
- while (*p != 0) {
- if (*p == '=') {
+/* decode quoted-printable MIME part */
+static int mime_decode_qp(FILE* in, FILE* out, uschar* boundary)
+{
+ uschar ibuf[MIME_MAX_LINE_LENGTH], obuf[MIME_MAX_LINE_LENGTH];
+ uschar *ipos, *opos;
+ size_t len, size = 0;
+
+ while (fgets(CS ibuf, MIME_MAX_LINE_LENGTH, in) != NULL)
+ {
+ if (boundary != NULL
+ && Ustrncmp(ibuf, "--", 2) == 0
+ && Ustrncmp((ibuf+2), boundary, Ustrlen(boundary)) == 0
+ )
+ break; /* todo: check for missing boundary */
+
+ ipos = ibuf;
+ opos = obuf;
+
+ while (*ipos != 0) {
+ if (*ipos == '=') {
int decode_qp_result;
- p = mime_decode_qp_char(p,&decode_qp_result);
+ ipos = mime_decode_qp_char(ipos, &decode_qp_result);
if (decode_qp_result == -2) {
- /* Error from decoder. p is unchanged. */
+ /* Error from decoder. ipos is unchanged. */
mime_set_anomaly(MIME_ANOMALY_BROKEN_QP);
- data[(*num_decoded)] = '=';
- (*num_decoded)++;
- p++;
+ *opos = '=';
+ ++opos;
+ ++ipos;
}
else if (decode_qp_result == -1) {
break;
}
else if (decode_qp_result >= 0) {
- data[(*num_decoded)] = decode_qp_result;
- (*num_decoded)++;
- };
+ *opos = decode_qp_result;
+ ++opos;
+ }
}
else {
- data[(*num_decoded)] = *p;
- (*num_decoded)++;
- p++;
- };
- };
- return data;
- /* ----------------------------------------------------------------- */
+ *opos = *ipos;
+ ++opos;
+ ++ipos;
+ }
+ }
+ /* something to write? */
+ len = opos - obuf;
+ if (len > 0) {
+ if (fwrite(obuf, 1, len, out) != len)
+ return -1; /* error */
+ size += len;
+ }
}
- /* unknown encoding type, just dump as-is */
- else goto NO_DECODING;
+ return size;
}
@@ -238,10 +272,9 @@
uschar option_buffer[1024];
uschar decode_path[1024];
FILE *decode_file = NULL;
- uschar *buffer = NULL;
- uschar *decode_buffer = NULL;
long f_pos = 0;
unsigned int size_counter = 0;
+ int (*decode_function)(FILE*, FILE*, uschar*);
if (mime_stream == NULL)
return FAIL;
@@ -251,21 +284,6 @@
/* build default decode path (will exist since MBOX must be spooled up) */
(void)string_format(decode_path,1024,"%s/scan/%s",spool_directory,message_id);
- /* reserve a line and decoder buffer to work in */
- buffer = (uschar *)malloc(MIME_MAX_LINE_LENGTH+1);
- if (buffer == NULL) {
- log_write(0, LOG_PANIC,
- "decode ACL condition: can't allocate %d bytes of memory.", MIME_MAX_LINE_LENGTH+1);
- return DEFER;
- };
-
- decode_buffer = (uschar *)malloc(MIME_MAX_LINE_LENGTH+1);
- if (decode_buffer == NULL) {
- log_write(0, LOG_PANIC,
- "decode ACL condition: can't allocate %d bytes of memory.", MIME_MAX_LINE_LENGTH+1);
- return DEFER;
- };
-
/* try to find 1st option */
if ((option = string_nextinlist(&list, &sep,
option_buffer,
@@ -306,50 +324,28 @@
if (decode_file == NULL)
return DEFER;
- /* read data linewise and dump it to the file,
- while looking for the current boundary */
- while(fgets(CS buffer, MIME_MAX_LINE_LENGTH, mime_stream) != NULL) {
- uschar *decoded_line = NULL;
- int decoded_line_length = 0;
-
- if (mime_current_boundary != NULL) {
- /* boundary line must start with 2 dashes */
- if (Ustrncmp(buffer,"--",2) == 0) {
- if (Ustrncmp((buffer+2),mime_current_boundary,Ustrlen(mime_current_boundary)) == 0)
- break;
- };
- };
-
- decoded_line = mime_parse_line(buffer, decode_buffer, mime_content_transfer_encoding, &decoded_line_length);
-
- /* write line to decode file */
- if (fwrite(decoded_line, 1, decoded_line_length, decode_file) < decoded_line_length) {
- /* error/short write */
- clearerr(mime_stream);
- fseek(mime_stream,f_pos,SEEK_SET);
- return DEFER;
- };
- size_counter += decoded_line_length;
-
- if (size_counter > 1023) {
- if ((mime_content_size + (size_counter / 1024)) < 65535)
- mime_content_size += (size_counter / 1024);
- else
- mime_content_size = 65535;
- size_counter = (size_counter % 1024);
- };
-
- }
+ /* decode according to mime type */
+ if (mime_content_transfer_encoding == NULL)
+ /* no encoding, dump as-is */
+ decode_function = mime_decode_asis;
+ else if (Ustrcmp(mime_content_transfer_encoding, "base64") == 0)
+ decode_function = mime_decode_base64;
+ else if (Ustrcmp(mime_content_transfer_encoding, "quoted-printable") == 0)
+ decode_function = mime_decode_qp;
+ else
+ /* unknown encoding type, just dump as-is */
+ decode_function = mime_decode_asis;
- (void)fclose(decode_file);
+ size_counter = decode_function(mime_stream, decode_file, mime_current_boundary);
clearerr(mime_stream);
- fseek(mime_stream,f_pos,SEEK_SET);
+ fseek(mime_stream, f_pos, SEEK_SET);
- /* round up remaining size bytes to one k */
- if (size_counter) {
- mime_content_size++;
- };
+ if (size_counter < 0 || fclose(decode_file) != 0)
+ return DEFER;
+
+ /* round up to the next KiB */
+ mime_content_size = (size_counter + 1023) / 1024;
return OK;
}
