-/* $Cambridge: exim/src/src/mime.c,v 1.3 2004/12/17 14:52:44 ph10 Exp $ */
-
/*************************************************
* Exim - an Internet mail transport agent *
*************************************************/
give info on detected "problems" in MIME
encodings. Those are defined in mime.h. */
-void mime_set_anomaly(int level, char *text) {
+void mime_set_anomaly(int level, const char *text) {
mime_anomaly_level = level;
- mime_anomaly_text = US text;
+ mime_anomaly_text = CUS text;
}
0-255 - char to write
*/
-unsigned int mime_qp_hstr_i(uschar *cptr) {
- unsigned int i, j = 0;
- while (cptr && *cptr && isxdigit(*cptr)) {
- i = *cptr++ - '0';
- if (9 < i) i -= 7;
- j <<= 4;
- j |= (i & 0x0f);
- }
- return(j);
-}
-
-uschar *mime_decode_qp_char(uschar *qp_p,int *c) {
- uschar hex[] = {0,0,0};
- int nan = 0;
+uschar *mime_decode_qp_char(uschar *qp_p, int *c) {
uschar *initial_pos = qp_p;
-
+
/* advance one char */
qp_p++;
-
- REPEAT_FIRST:
- if ( (*qp_p == '\t') || (*qp_p == ' ') || (*qp_p == '\r') ) {
- /* tab or whitespace may follow
- just ignore it, but remember
- that this is not a valid hex
- encoding any more */
- nan = 1;
+
+ /* Check for two hex digits and decode them */
+ if (isxdigit(*qp_p) && isxdigit(qp_p[1])) {
+ /* Do hex conversion */
+ if (isdigit(*qp_p)) {*c = *qp_p - '0';}
+ else {*c = toupper(*qp_p) - 'A' + 10;};
+ *c <<= 4;
+ if (isdigit(qp_p[1])) {*c |= qp_p[1] - '0';}
+ else {*c |= toupper(qp_p[1]) - 'A' + 10;};
+ return qp_p + 2;
+ };
+
+ /* tab or whitespace may follow just ignore it if it precedes \n */
+ while (*qp_p == '\t' || *qp_p == ' ' || *qp_p == '\r')
qp_p++;
- goto REPEAT_FIRST;
- }
- else if ( (('0' <= *qp_p) && (*qp_p <= '9')) || (('A' <= *qp_p) && (*qp_p <= 'F')) || (('a' <= *qp_p) && (*qp_p <= 'f')) ) {
- /* this is a valid hex char, if nan is unset */
- if (nan) {
- /* this is illegal */
- *c = -2;
- return initial_pos;
- }
- else {
- hex[0] = *qp_p;
- qp_p++;
- };
- }
- else if (*qp_p == '\n') {
- /* hit soft line break already, continue */
+
+ if (*qp_p == '\n') {
+ /* hit soft line break */
*c = -1;
return qp_p;
- }
- else {
- /* illegal char here */
- *c = -2;
- return initial_pos;
- };
-
- if ( (('0' <= *qp_p) && (*qp_p <= '9')) || (('A' <= *qp_p) && (*qp_p <= 'F')) || (('a' <= *qp_p) && (*qp_p <= 'f')) ) {
- if (hex[0] > 0) {
- hex[1] = *qp_p;
- /* do hex conversion */
- *c = mime_qp_hstr_i(hex);
- qp_p++;
- return qp_p;
- }
- else {
- /* huh ? */
- *c = -2;
- return initial_pos;
- };
- }
- else {
- /* illegal char */
- *c = -2;
- return initial_pos;
};
+
+ /* illegal char here */
+ *c = -2;
+ return initial_pos;
}
-uschar *mime_parse_line(uschar *buffer, uschar *encoding, int *num_decoded) {
- uschar *data = NULL;
+/* just dump MIME part without any decoding */
+static ssize_t
+mime_decode_asis(FILE* in, FILE* out, uschar* boundary)
+{
+ ssize_t len, size = 0;
+ uschar buffer[MIME_MAX_LINE_LENGTH];
- data = (uschar *)malloc(Ustrlen(buffer)+2);
+ 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) {
- mime_set_anomaly(MIME_ANOMALY_BROKEN_BASE64);
- offset++;
- }
- else {
- *p = mime_b64[*(p+offset)];
- p++;
- };
- };
- *p = 255;
-
- /* line is translated, start bit shifting */
- p = buffer;
- *num_decoded = 0;
- while(*p != 255) {
- uschar tmp_c;
-
- /* byte 0 ---------------------- */
- if (*(p+1) == 255) {
- mime_set_anomaly(MIME_ANOMALY_BROKEN_BASE64);
- 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) {
- mime_set_anomaly(MIME_ANOMALY_BROKEN_BASE64);
- break;
+/* 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) {
+ /* skip padding */
+ if (*ipos == '=') {
+ ++bytestate;
+ continue;
}
- 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) {
+ /* skip bad characters */
+ if (mime_b64[*ipos] == 128) {
mime_set_anomaly(MIME_ANOMALY_BROKEN_BASE64);
- break;
+ continue;
}
- data[(*num_decoded)] = *p;
- data[(*num_decoded)] <<= 6;
- data[(*num_decoded)] |= *(p+1);
- (*num_decoded)++;
- p+=2;
-
- };
- return data;
- /* ----------------------------------------------------------------- */
+ /* 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;
}
- else if (Ustrcmp(encoding,"quoted-printable") == 0) {
- uschar *p = buffer;
- /* ----- QP -------------------------------------------------------- */
- *num_decoded = 0;
- while (*p != 0) {
- if (*p == '=') {
+ return size;
+}
+
+
+/* decode quoted-printable MIME part */
+static ssize_t
+mime_decode_qp(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;
+
+ 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;
}
FILE *mime_get_decode_file(uschar *pname, uschar *fname) {
FILE *f = NULL;
uschar *filename;
-
+
filename = (uschar *)malloc(2048);
-
+
if ((pname != NULL) && (fname != NULL)) {
- snprintf(CS filename, 2048, "%s/%s", pname, fname);
- f = fopen(CS filename,"w+");
+ (void)string_format(filename, 2048, "%s/%s", pname, fname);
+ f = modefopen(filename,"wb+",SPOOL_MODE);
}
else if (pname == NULL) {
- f = fopen(CS fname,"w+");
+ f = modefopen(fname,"wb+",SPOOL_MODE);
}
else if (fname == NULL) {
int file_nr = 0;
/* must find first free sequential filename */
do {
struct stat mystat;
- snprintf(CS filename,2048,"%s/%s-%05u", pname, message_id, file_nr);
+ (void)string_format(filename,2048,"%s/%s-%05u", pname, message_id, file_nr);
file_nr++;
/* security break */
if (file_nr >= 1024)
result = stat(CS filename,&mystat);
}
while(result != -1);
- f = fopen(CS filename,"w+");
+ f = modefopen(filename,"wb+",SPOOL_MODE);
};
-
+
/* set expansion variable */
mime_decoded_filename = filename;
-
+
return f;
}
uschar option_buffer[1024];
uschar decode_path[1024];
FILE *decode_file = NULL;
- uschar *buffer = NULL;
long f_pos = 0;
- unsigned int size_counter = 0;
+ ssize_t size_counter = 0;
+ ssize_t (*decode_function)(FILE*, FILE*, uschar*);
if (mime_stream == NULL)
return FAIL;
-
+
f_pos = ftell(mime_stream);
-
+
/* build default decode path (will exist since MBOX must be spooled up) */
- snprintf(CS decode_path,1024,"%s/scan/%s",spool_directory,message_id);
-
- /* reserve a line 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;
- };
-
+ (void)string_format(decode_path,1024,"%s/scan/%s",spool_directory,message_id);
+
/* try to find 1st option */
if ((option = string_nextinlist(&list, &sep,
option_buffer,
sizeof(option_buffer))) != NULL) {
-
+
/* parse 1st option */
if ( (Ustrcmp(option,"false") == 0) || (Ustrcmp(option,"0") == 0) ) {
/* explicitly no decoding */
return FAIL;
};
-
+
if (Ustrcmp(option,"default") == 0) {
/* explicit default path + file names */
goto DEFAULT_PATH;
};
-
+
if (option[0] == '/') {
struct stat statbuf;
memset(&statbuf,0,sizeof(statbuf));
-
+
/* assume either path or path+file name */
if ( (stat(CS option, &statbuf) == 0) && S_ISDIR(statbuf.st_mode) )
/* is directory, use it as decode_path */
else
/* no option? patch default path */
DEFAULT_PATH: decode_file = mime_get_decode_file(decode_path, NULL);
-
+
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, 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);
- };
-
- free(decoded_line);
- }
-
- fclose(decode_file);
-
+
+ /* 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;
+
+ size_counter = decode_function(mime_stream, decode_file, mime_current_boundary);
+
clearerr(mime_stream);
- fseek(mime_stream,f_pos,SEEK_SET);
-
- /* round up remaining size bytes to one k */
- if (size_counter) {
- mime_content_size++;
- };
-
+ fseek(mime_stream, f_pos, SEEK_SET);
+
+ if (fclose(decode_file) != 0 || size_counter < 0)
+ return DEFER;
+
+ /* round up to the next KiB */
+ mime_content_size = (size_counter + 1023) / 1024;
+
return OK;
}
int header_value_mode = 0;
int header_open_brackets = 0;
int num_copied = 0;
-
+
while(!done) {
-
+
c = fgetc(f);
if (c == EOF) break;
-
+
/* always skip CRs */
if (c == '\r') continue;
-
+
if (c == '\n') {
if (num_copied > 0) {
/* look if next char is '\t' or ' ' */
c = fgetc(f);
if (c == EOF) break;
if ( (c == '\t') || (c == ' ') ) continue;
- ungetc(c,f);
+ (void)ungetc(c,f);
};
/* end of the header, terminate with ';' */
c = ';';
done = 1;
};
-
+
/* skip control characters */
if (c < 32) continue;
/* skip leading whitespace */
if ( ((c == '\t') || (c == ' ')) && (header_value_mode == 1) )
continue;
-
+
/* we have hit a non-whitespace char, start copying value data */
header_value_mode = 2;
-
+
/* skip quotes */
if (c == '"') continue;
-
+
/* leave value mode on ';' */
if (c == ';') {
header_value_mode = 0;
/* enter value mode */
header_value_mode = 1;
};
-
+
/* skip chars while we are in a comment */
if (header_open_brackets > 0)
continue;
/* -------------------------------- */
};
-
+
/* copy the char to the buffer */
header[num_copied] = (uschar)c;
/* raise counter */
num_copied++;
-
+
/* break if header buffer is full */
if (num_copied > MIME_MAX_HEADER_SIZE-1) {
done = 1;
};
};
- if (header[num_copied-1] != ';') {
+ if ((num_copied > 0) && (header[num_copied-1] != ';')) {
header[num_copied-1] = ';';
};
/* 0-terminate */
header[num_copied] = '\0';
-
+
/* return 0 for EOF or empty line */
if ((c == EOF) || (num_copied == 1))
return 0;
}
-int mime_acl_check(FILE *f, struct mime_boundary_context *context, uschar
- **user_msgptr, uschar **log_msgptr) {
+int mime_acl_check(uschar *acl, FILE *f, struct mime_boundary_context *context,
+ uschar **user_msgptr, uschar **log_msgptr) {
int rc = OK;
uschar *header = NULL;
struct mime_boundary_context nested_context;
header = (uschar *)malloc(MIME_MAX_HEADER_SIZE+1);
if (header == NULL) {
log_write(0, LOG_PANIC,
- "acl_smtp_mime: can't allocate %d bytes of memory.", MIME_MAX_HEADER_SIZE+1);
+ "MIME ACL: can't allocate %d bytes of memory.", MIME_MAX_HEADER_SIZE+1);
return DEFER;
};
/* loop through parts */
while(1) {
-
+
/* reset all per-part mime variables */
mime_anomaly_level = 0;
mime_anomaly_text = NULL;
mime_content_type = NULL;
mime_is_multipart = 0;
mime_content_size = 0;
-
+
/*
If boundary is null, we assume that *f is positioned on the start of headers (for example,
at the very beginning of a message.
If a boundary is given, we must first advance to it to reach the start of the next header
block.
*/
-
+
/* NOTE -- there's an error here -- RFC2046 specifically says to
* check for outer boundaries. This code doesn't do that, and
* I haven't fixed this.
*
- * (I have moved partway towards adding support, however, by adding
+ * (I have moved partway towards adding support, however, by adding
* a "parent" field to my new boundary-context structure.)
*/
if (context != NULL) {
debug_printf("Hit EOF ...\n");
return rc;
};
-
+
DECODE_HEADERS:
/* parse headers, set up expansion variables */
while(mime_get_header(f,header)) {
for (i = 0; i < mime_header_list_size; i++) {
uschar *header_value = NULL;
int header_value_len = 0;
-
+
/* found an interesting header? */
if (strncmpic(mime_header_list[i].name,header,mime_header_list[i].namelen) == 0) {
uschar *p = header + mime_header_list[i].namelen;
Ustrncpy(header_value, p, header_value_len);
debug_printf("Found %s MIME header, value is '%s'\n", mime_header_list[i].name, header_value);
*((uschar **)(mime_header_list[i].value)) = header_value;
-
+
/* make p point to the next character after the closing ';' */
p += (header_value_len+1);
-
+
/* grab all param=value tags on the remaining line, check if they are interesting */
NEXT_PARAM_SEARCH: while (*p != 0) {
int j;
for (j = 0; j < mime_parameter_list_size; j++) {
uschar *param_value = NULL;
int param_value_len = 0;
-
+
/* found an interesting parameter? */
if (strncmpic(mime_parameter_list[j].name,p,mime_parameter_list[j].namelen) == 0) {
uschar *q = p + mime_parameter_list[j].namelen;
memset(param_value,0,param_value_len+1);
q = p + mime_parameter_list[j].namelen;
Ustrncpy(param_value, q, param_value_len);
- param_value = rfc2047_decode(param_value, TRUE, NULL, 32, ¶m_value_len, &q);
+ param_value = rfc2047_decode(param_value, check_rfc2047_length, NULL, 32, ¶m_value_len, &q);
debug_printf("Found %s MIME parameter in %s header, value is '%s'\n", mime_parameter_list[j].name, mime_header_list[i].name, param_value);
*((uschar **)(mime_parameter_list[j].value)) = param_value;
p += (mime_parameter_list[j].namelen + param_value_len + 1);
};
};
};
-
+
/* set additional flag variables (easier access) */
if ( (mime_content_type != NULL) &&
(Ustrncmp(mime_content_type,"multipart",9) == 0) )
mime_is_multipart = 1;
-
+
/* Make a copy of the boundary pointer.
Required since mime_boundary is global
and can be overwritten further down in recursion */
nested_context.boundary = mime_boundary;
-
+
/* raise global counter */
mime_part_count++;
-
+
/* copy current file handle to global variable */
mime_stream = f;
mime_current_boundary = context ? context->boundary : 0;
/* Note the context */
mime_is_coverletter = !(context && context->context == MBC_ATTACHMENT);
-
+
/* call ACL handling function */
- rc = acl_check(ACL_WHERE_MIME, NULL, acl_smtp_mime, user_msgptr, log_msgptr);
-
+ rc = acl_check(ACL_WHERE_MIME, NULL, acl, user_msgptr, log_msgptr);
+
mime_stream = NULL;
mime_current_boundary = NULL;
-
+
if (rc != OK) break;
-
+
/* If we have a multipart entity and a boundary, go recursive */
if ( (mime_content_type != NULL) &&
(nested_context.boundary != NULL) &&
else
nested_context.context = MBC_COVERLETTER_ONESHOT;
- rc = mime_acl_check(f, &nested_context, user_msgptr, log_msgptr);
+ rc = mime_acl_check(acl, f, &nested_context, user_msgptr, log_msgptr);
if (rc != OK) break;
}
else if ( (mime_content_type != NULL) &&
uschar filename[2048];
int file_nr = 0;
int result = 0;
-
+
/* must find first free sequential filename */
do {
struct stat mystat;
- snprintf(CS filename,2048,"%s/scan/%s/__rfc822_%05u", spool_directory, message_id, file_nr);
+ (void)string_format(filename,2048,"%s/scan/%s/__rfc822_%05u", spool_directory, message_id, file_nr);
file_nr++;
/* security break */
if (file_nr >= 128)
result = stat(CS filename,&mystat);
}
while(result != -1);
-
+
rfc822name = filename;
-
+
/* decode RFC822 attachment */
mime_decoded_filename = NULL;
mime_stream = f;
};
mime_decoded_filename = NULL;
};
-
+
NO_RFC822:
/* If the boundary of this instance is NULL, we are finished here */
if (context == NULL) break;
if (context->context == MBC_COVERLETTER_ONESHOT)
context->context = MBC_ATTACHMENT;
-
+
};
return rc;
git://git.exim.org / users / heiko / exim.git / blobdiff