-/* $Cambridge: exim/src/src/mime.c,v 1.2 2004/12/16 15:11:47 tom Exp $ */
-
/*************************************************
* 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 2015 - 2020
+ */
#include "exim.h"
-#ifdef WITH_CONTENT_SCAN
+#ifdef WITH_CONTENT_SCAN /* entire file */
#include "mime.h"
#include <sys/stat.h>
FILE *mime_stream = NULL;
uschar *mime_current_boundary = NULL;
+static mime_header mime_header_list[] = {
+ /* name namelen value */
+ { 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[] = {
+ /* name namelen value */
+ { 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. */
-
-void mime_set_anomaly(int level, char *text) {
- mime_anomaly_level = level;
- mime_anomaly_text = text;
-};
+ encodings. Indexes are defined in mime.h. */
+
+void
+mime_set_anomaly(int idx)
+{
+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;
+}
/*************************************************
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);
+static uschar *
+mime_decode_qp_char(uschar *qp_p, int *c)
+{
+uschar *initial_pos = qp_p;
+
+/* advance one char */
+qp_p++;
+
+/* Check for two hex digits and decode them */
+if (isxdigit(*qp_p) && isxdigit(qp_p[1]))
+ {
+ /* Do hex conversion */
+ *c = (isdigit(*qp_p) ? *qp_p - '0' : toupper(*qp_p) - 'A' + 10) <<4;
+ qp_p++;
+ *c |= isdigit(*qp_p) ? *qp_p - '0' : toupper(*qp_p) - 'A' + 10;
+ return qp_p + 1;
}
- return(j);
-}
-uschar *mime_decode_qp_char(uschar *qp_p,int *c) {
- uschar hex[] = {0,0,0};
- int nan = 0;
- uschar *initial_pos = qp_p;
-
- /* advance one char */
+/* tab or whitespace may follow just ignore it if it precedes \n */
+while (*qp_p == '\t' || *qp_p == ' ' || *qp_p == '\r')
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;
- qp_p++;
- goto REPEAT_FIRST;
+
+if (*qp_p == '\n') /* hit soft line break */
+ {
+ *c = -1;
+ return qp_p;
}
- 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;
+
+/* illegal char here */
+*c = -2;
+return initial_pos;
+}
+
+
+/* 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];
+
+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;
+}
+
+
+
+/* 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;
+
+ ipos = mime_decode_qp_char(ipos, &decode_qp_result);
+
+ if (decode_qp_result == -2)
+ {
+ /* Error from decoder. ipos is unchanged. */
+ mime_set_anomaly(MIME_ANOMALY_BROKEN_QP);
+ *opos++ = '=';
+ ++ipos;
+ }
+ else if (decode_qp_result == -1)
+ break;
+ else if (decode_qp_result >= 0)
+ *opos++ = decode_qp_result;
+ }
+ else
+ *opos++ = *ipos++;
}
- else {
- hex[0] = *qp_p;
- qp_p++;
- };
- }
- else if (*qp_p == '\n') {
- /* hit soft line break already, continue */
- *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;
+ /* something to write? */
+ len = opos - obuf;
+ if (len > 0)
+ {
+ if (fwrite(obuf, 1, len, out) != len) return -1; /* error */
+ size += len;
}
- else {
- /* huh ? */
- *c = -2;
- return initial_pos;
- };
}
- else {
- /* illegal char */
- *c = -2;
- return initial_pos;
- };
+return size;
+}
+
+
+/*
+ * 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)
+{
+if (pname && fname)
+ mime_decoded_filename = string_sprintf("%s/%s", pname, fname);
+else if (!pname)
+ mime_decoded_filename = string_copy(fname);
+else if (!fname)
+ {
+ int file_nr = 0;
+ int result = 0;
+
+ /* must find first free sequential filename */
+ do
+ {
+ struct stat mystat;
+ mime_decoded_filename = string_sprintf("%s/%s-%05u", pname, message_id, file_nr++);
+ /* security break */
+ if (file_nr >= 1024)
+ break;
+ result = stat(CS mime_decoded_filename, &mystat);
+ } while(result != -1);
+ }
+
+return modefopen(mime_decoded_filename, "wb+", SPOOL_MODE);
}
-uschar *mime_parse_line(uschar *buffer, uschar *encoding, int *num_decoded) {
- uschar *data = NULL;
+int
+mime_decode(const uschar **listptr)
+{
+int sep = 0;
+const uschar *list = *listptr;
+uschar * option;
+uschar * decode_path;
+FILE *decode_file = NULL;
+long f_pos = 0;
+ssize_t size_counter = 0;
+ssize_t (*decode_function)(FILE*, FILE*, uschar*);
+
+if (!mime_stream || (f_pos = ftell(mime_stream)) < 0)
+ return FAIL;
+
+/* build default decode path (will exist since MBOX must be spooled up) */
+decode_path = string_sprintf("%s/scan/%s", spool_directory, message_id);
+
+/* try to find 1st option */
+if ((option = string_nextinlist(&list, &sep, NULL, 0)))
+ {
+ /* 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;
- data = (uschar *)malloc(Ustrlen(buffer)+2);
+ if (option[0] == '/')
+ {
+ struct stat statbuf;
- 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;
+ 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 */
+ decode_file = mime_get_decode_file(option, NULL);
+ else
+ /* does not exist or is a file, use as full file name */
+ decode_file = mime_get_decode_file(NULL, option);
+ }
+ else
+ /* assume file name only, use default path */
+ decode_file = mime_get_decode_file(decode_path, option);
}
- 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;
+else
+ {
+ /* no option? patch default path */
+DEFAULT_PATH:
+ decode_file = mime_get_decode_file(decode_path, NULL);
+ }
+
+if (!decode_file)
+ return DEFER;
+
+/* decode according to mime type */
+decode_function =
+ !mime_content_transfer_encoding
+ ? mime_decode_asis /* no encoding, dump as-is */
+ : Ustrcmp(mime_content_transfer_encoding, "base64") == 0
+ ? mime_decode_base64
+ : Ustrcmp(mime_content_transfer_encoding, "quoted-printable") == 0
+ ? mime_decode_qp
+ : mime_decode_asis; /* unknown encoding type, just dump as-is */
+
+size_counter = decode_function(mime_stream, decode_file, mime_current_boundary);
+
+clearerr(mime_stream);
+if (fseek(mime_stream, f_pos, SEEK_SET))
+ return DEFER;
+
+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;
+}
+
+
+static int
+mime_get_header(FILE *f, uschar *header)
+{
+int c = EOF;
+int done = 0;
+int header_value_mode = 0;
+int header_open_brackets = 0;
+int num_copied = 0;
+
+while(!done)
+ {
+ if ((c = fgetc(f)) == EOF) break;
+
+ /* always skip CRs */
+ if (c == '\r') continue;
+
+ if (c == '\n')
+ {
+ if (num_copied > 0)
+ {
+ /* look if next char is '\t' or ' ' */
+ if ((c = fgetc(f)) == EOF) break;
+ if ( (c == '\t') || (c == ' ') ) continue;
+ (void)ungetc(c,f);
}
- 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;
+ /* end of the header, terminate with ';' */
+ c = ';';
+ done = 1;
+ }
+
+ /* skip control characters */
+ if (c < 32) continue;
+
+ if (header_value_mode)
+ {
+ /* --------- value mode ----------- */
+ /* 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;
+
+ if (c == '"') /* flip "quoted" mode */
+ header_value_mode = header_value_mode==2 ? 3 : 2;
+
+ /* leave value mode on unquoted ';' */
+ if (header_value_mode == 2 && c == ';')
+ header_value_mode = 0;
+ /* -------------------------------- */
+ }
+ else
+ {
+ /* -------- non-value mode -------- */
+ /* skip whitespace + tabs */
+ if ( (c == ' ') || (c == '\t') )
+ continue;
+ if (c == '\\')
+ {
+ /* quote next char. can be used
+ to escape brackets. */
+ if ((c = fgetc(f)) == EOF) 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) {
- mime_set_anomaly(MIME_ANOMALY_BROKEN_BASE64);
- break;
+ else if (c == '(')
+ {
+ header_open_brackets++;
+ continue;
}
- data[(*num_decoded)] = *p;
- data[(*num_decoded)] <<= 6;
- data[(*num_decoded)] |= *(p+1);
- (*num_decoded)++;
- p+=2;
-
- };
- return data;
- /* ----------------------------------------------------------------- */
- }
- else if (Ustrcmp(encoding,"quoted-printable") == 0) {
- uschar *p = buffer;
-
- /* ----- QP -------------------------------------------------------- */
- *num_decoded = 0;
- while (*p != 0) {
- if (*p == '=') {
- int decode_qp_result;
-
- p = mime_decode_qp_char(p,&decode_qp_result);
-
- if (decode_qp_result == -2) {
- /* Error from decoder. p is unchanged. */
- mime_set_anomaly(MIME_ANOMALY_BROKEN_QP);
- data[(*num_decoded)] = '=';
- (*num_decoded)++;
- p++;
- }
- else if (decode_qp_result == -1) {
- break;
- }
- else if (decode_qp_result >= 0) {
- data[(*num_decoded)] = decode_qp_result;
- (*num_decoded)++;
- };
+ else if ((c == ')') && header_open_brackets)
+ {
+ header_open_brackets--;
+ continue;
}
- else {
- data[(*num_decoded)] = *p;
- (*num_decoded)++;
- p++;
- };
- };
- return data;
- /* ----------------------------------------------------------------- */
+ else if ( (c == '=') && !header_open_brackets ) /* 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;
+
+ /* break if header buffer is full */
+ if (num_copied > MIME_MAX_HEADER_SIZE-1)
+ done = 1;
}
- /* unknown encoding type, just dump as-is */
- else goto NO_DECODING;
+
+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 */
+return c == EOF || num_copied == 1 ? 0 : 1;
}
-FILE *mime_get_decode_file(uschar *pname, uschar *fname) {
- FILE *f;
- uschar *filename;
-
- filename = (uschar *)malloc(2048);
-
- if ((pname != NULL) && (fname != NULL)) {
- snprintf(CS filename, 2048, "%s/%s", pname, fname);
- f = fopen(CS filename,"w+");
- }
- else if (pname == NULL) {
- f = fopen(CS fname,"w+");
- }
- else if (fname == NULL) {
- int file_nr = 0;
- int result = 0;
+/* reset all per-part mime variables */
+static void
+mime_vars_reset(void)
+{
+mime_anomaly_level = 0;
+mime_anomaly_text = NULL;
+mime_boundary = NULL;
+mime_charset = NULL;
+mime_decoded_filename = NULL;
+mime_filename = NULL;
+mime_content_description = NULL;
+mime_content_disposition = NULL;
+mime_content_id = NULL;
+mime_content_transfer_encoding = NULL;
+mime_content_type = NULL;
+mime_is_multipart = 0;
+mime_content_size = 0;
+}
- /* must find first free sequential filename */
- do {
- struct stat mystat;
- snprintf(CS filename,2048,"%s/%s-%05u", pname, message_id, file_nr);
- file_nr++;
- /* security break */
- if (file_nr >= 1024)
- break;
- result = stat(CS filename,&mystat);
+
+/* Grab a parameter value, dealing with quoting.
+
+Arguments:
+ str Input string. Updated on return to point to terminating ; or NUL
+
+Return:
+ Allocated string with parameter value
+*/
+static uschar *
+mime_param_val(uschar ** sp)
+{
+uschar * s = *sp;
+gstring * val = NULL;
+
+/* debug_printf_indent(" considering paramval '%s'\n", s); */
+
+while (*s && *s != ';') /* ; terminates */
+ if (*s == '"')
+ {
+ s++; /* skip opening " */
+ while (*s && *s != '"') /* " protects ; */
+ val = string_catn(val, s++, 1);
+ if (*s) s++; /* skip closing " */
+ }
+ else
+ val = string_catn(val, s++, 1);
+*sp = s;
+return string_from_gstring(val);
+}
+
+static uschar *
+mime_next_semicolon(uschar * s)
+{
+while (*s && *s != ';') /* ; terminates */
+ if (*s == '"')
+ {
+ s++; /* skip opening " */
+ while (*s && *s != '"') /* " protects ; */
+ s++;
+ if (*s) s++; /* skip closing " */
}
- while(result != -1);
- f = fopen(CS filename,"w+");
- };
-
- /* set expansion variable */
- mime_decoded_filename = filename;
-
- return f;
+ else
+ s++;
+return s;
}
-int mime_decode(uschar **listptr) {
- int sep = 0;
- uschar *list = *listptr;
- uschar *option;
- uschar option_buffer[1024];
- uschar decode_path[1024];
- FILE *decode_file = NULL;
- uschar *buffer = NULL;
- long f_pos = 0;
- unsigned int size_counter = 0;
+static uschar *
+rfc2231_to_2047(const uschar * fname, const uschar * charset, int * len)
+{
+gstring * val = string_catn(NULL, US"=?", 2);
+uschar c;
- 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;
- };
-
- /* 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 */
- decode_file = mime_get_decode_file(option, NULL);
- else
- /* does not exist or is a file, use as full file name */
- decode_file = mime_get_decode_file(NULL, option);
+if (charset)
+ val = string_cat(val, charset);
+val = string_catn(val, US"?Q?", 3);
+
+while ((c = *fname))
+ if (c == '%' && isxdigit(fname[1]) && isxdigit(fname[2]))
+ {
+ val = string_catn(val, US"=", 1);
+ val = string_catn(val, ++fname, 2);
+ fname += 2;
}
- else
- /* assume file name only, use default path */
- decode_file = mime_get_decode_file(decode_path, option);
- }
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);
-
- clearerr(mime_stream);
- fseek(mime_stream,f_pos,SEEK_SET);
-
- /* round up remaining size bytes to one k */
- if (size_counter) {
- mime_content_size++;
- };
-
- return OK;
+ val = string_catn(val, fname++, 1);
+
+val = string_catn(val, US"?=", 2);
+*len = val->ptr;
+return string_from_gstring(val);
}
-int mime_get_header(FILE *f, uschar *header) {
- int c = EOF;
- int done = 0;
- 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);
- };
- /* end of the header, terminate with ';' */
- c = ';';
- done = 1;
- };
-
- /* skip control characters */
- if (c < 32) continue;
-
- if (header_value_mode) {
- /* --------- value mode ----------- */
- /* 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;
- };
- /* -------------------------------- */
- }
- else {
- /* -------- non-value mode -------- */
- /* skip whitespace + tabs */
- if ( (c == ' ') || (c == '\t') )
- continue;
- if (c == '\\') {
- /* quote next char. can be used
- to escape brackets. */
- c = fgetc(f);
- if (c == EOF) break;
+
+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;
+
+/* reserve a line buffer to work in. Assume tainted data. */
+header = store_get(MIME_MAX_HEADER_SIZE+1, TRUE);
+
+/* Not actually used at the moment, but will be vital to fixing
+ * some RFC 2046 nonconformance later... */
+nested_context.parent = context;
+
+/* loop through parts */
+while(1)
+ {
+ /* reset all per-part mime variables */
+ mime_vars_reset();
+
+ /* 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
+ * a "parent" field to my new boundary-context structure.)
+ */
+ if (context) for (;;)
+ {
+ if (!fgets(CS header, MIME_MAX_HEADER_SIZE, f))
+ {
+ /* Hit EOF or read error. Ugh. */
+ DEBUG(D_acl) debug_printf_indent("MIME: Hit EOF ...\n");
+ return rc;
}
- else if (c == '(') {
- header_open_brackets++;
- continue;
+
+ /* boundary line must start with 2 dashes */
+ if ( Ustrncmp(header, "--", 2) == 0
+ && Ustrncmp(header+2, context->boundary, Ustrlen(context->boundary)) == 0
+ )
+ { /* found boundary */
+ if (Ustrncmp((header+2+Ustrlen(context->boundary)), "--", 2) == 0)
+ {
+ /* END boundary found */
+ DEBUG(D_acl) debug_printf_indent("MIME: End boundary found %s\n",
+ context->boundary);
+ return rc;
+ }
+
+ DEBUG(D_acl) debug_printf_indent("MIME: Next part with boundary %s\n",
+ context->boundary);
+ break;
}
- else if ((c == ')') && header_open_brackets) {
- header_open_brackets--;
- continue;
+ }
+
+ /* parse headers, set up expansion variables */
+ while (mime_get_header(f, header))
+
+ /* look for interesting headers */
+ for (struct mime_header * mh = mime_header_list;
+ mh < mime_header_list + mime_header_list_size;
+ mh++) if (strncmpic(mh->name, header, mh->namelen) == 0)
+ {
+ uschar * p = header + mh->namelen;
+ uschar * q;
+
+ /* grab the value (normalize to lower case)
+ and copy to its corresponding expansion variable */
+
+ for (q = p; *q != ';' && *q; q++) ;
+ *mh->value = string_copynlc(p, q-p);
+ DEBUG(D_acl) debug_printf_indent("MIME: found %s header, value is '%s'\n",
+ mh->name, *mh->value);
+
+ if (*(p = q)) p++; /* jump past the ; */
+
+ {
+ uschar * mime_fname = NULL;
+ uschar * mime_fname_rfc2231 = NULL;
+ uschar * mime_filename_charset = NULL;
+ BOOL decoding_failed = FALSE;
+
+ /* grab all param=value tags on the remaining line,
+ check if they are interesting */
+
+ while (*p)
+ {
+ DEBUG(D_acl) debug_printf_indent("MIME: considering paramlist '%s'\n", p);
+
+ if ( !mime_filename
+ && strncmpic(CUS"content-disposition:", header, 20) == 0
+ && strncmpic(CUS"filename*", p, 9) == 0
+ )
+ { /* RFC 2231 filename */
+ uschar * q;
+
+ /* find value of the filename */
+ p += 9;
+ while(*p != '=' && *p) p++;
+ if (*p) p++; /* p is filename or NUL */
+ q = mime_param_val(&p); /* p now trailing ; or NUL */
+
+ if (q && *q)
+ {
+ uschar * temp_string, * err_msg;
+ int slen;
+
+ /* build up an un-decoded filename over successive
+ filename*= parameters (for use when 2047 decode fails) */
+
+ mime_fname_rfc2231 = string_sprintf("%#s%s",
+ mime_fname_rfc2231, q);
+
+ if (!decoding_failed)
+ {
+ int size;
+ if (!mime_filename_charset)
+ {
+ uschar * s = q;
+
+ /* look for a ' in the "filename" */
+ while(*s != '\'' && *s) s++; /* s is 1st ' or NUL */
+
+ if ((size = s-q) > 0)
+ mime_filename_charset = string_copyn(q, size);
+
+ if (*(p = s)) p++;
+ while(*p == '\'') p++; /* p is after 2nd ' */
+ }
+ else
+ p = q;
+
+ DEBUG(D_acl) debug_printf_indent("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_indent("MIME: 2047-name %s\n", temp_string);
+
+ temp_string = rfc2047_decode(temp_string, FALSE, NULL, ' ',
+ NULL, &err_msg);
+ DEBUG(D_acl) debug_printf_indent("MIME: plain-name %s\n", temp_string);
+
+ if (!temp_string || (size = Ustrlen(temp_string)) == slen)
+ decoding_failed = TRUE;
+ else
+ /* build up a decoded filename over successive
+ filename*= parameters */
+
+ mime_filename = mime_fname = mime_fname
+ ? string_sprintf("%s%s", mime_fname, temp_string)
+ : temp_string;
+ }
+ }
+ }
+
+ else
+ /* look for interesting parameters */
+ for (mime_parameter * mp = mime_parameter_list;
+ mp < mime_parameter_list + nelem(mime_parameter_list);
+ mp++
+ ) if (strncmpic(mp->name, p, mp->namelen) == 0)
+ {
+ uschar * q;
+ uschar * dummy_errstr;
+
+ /* grab the value and copy to its expansion variable */
+ p += mp->namelen;
+ q = mime_param_val(&p); /* p now trailing ; or NUL */
+
+ *mp->value = q && *q
+ ? rfc2047_decode(q, check_rfc2047_length, NULL, 32, NULL,
+ &dummy_errstr)
+ : NULL;
+ DEBUG(D_acl) debug_printf_indent(
+ "MIME: found %s parameter in %s header, value '%s'\n",
+ mp->name, mh->name, *mp->value);
+
+ break; /* done matching param names */
+ }
+
+
+ /* There is something, but not one of our interesting parameters.
+ Advance past the next semicolon */
+ p = mime_next_semicolon(p);
+ if (*p) p++;
+ } /* param scan on line */
+
+ if (strncmpic(CUS"content-disposition:", header, 20) == 0)
+ {
+ if (decoding_failed) mime_filename = mime_fname_rfc2231;
+
+ DEBUG(D_acl) debug_printf_indent(
+ "MIME: found %s parameter in %s header, value is '%s'\n",
+ "filename", mh->name, mime_filename);
+ }
+ }
}
- else if ( (c == '=') && !header_open_brackets ) {
- /* 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] != ';') {
- 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;
- else
- return 1;
-}
+ /* set additional flag variables (easier access) */
+ if ( mime_content_type
+ && 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, 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 && nested_context.boundary
+ && Ustrncmp(mime_content_type,"multipart",9) == 0)
+ {
+ DEBUG(D_acl)
+ debug_printf_indent("MIME: Entering multipart recursion, boundary '%s'\n",
+ nested_context.boundary);
+
+ nested_context.context =
+ context && context->context == MBC_ATTACHMENT
+ ? MBC_ATTACHMENT
+ : Ustrcmp(mime_content_type,"multipart/alternative") == 0
+ || Ustrcmp(mime_content_type,"multipart/related") == 0
+ ? MBC_COVERLETTER_ALL
+ : MBC_COVERLETTER_ONESHOT;
+
+ rc = mime_acl_check(acl, f, &nested_context, user_msgptr, log_msgptr);
+ if (rc != OK) break;
+ }
+ else if ( mime_content_type
+ && Ustrncmp(mime_content_type,"message/rfc822",14) == 0)
+ {
+ const uschar * rfc822name = NULL;
+ uschar * filename;
+ int file_nr = 0;
+ int result = 0;
-int mime_acl_check(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;
-
- /* reserve a line buffer to work in */
- 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);
- return DEFER;
- };
-
- /* Not actually used at the moment, but will be vital to fixing
- * some RFC 2046 nonconformance later... */
- nested_context.parent = context;
-
- /* loop through parts */
- while(1) {
-
- /* reset all per-part mime variables */
- mime_anomaly_level = NULL;
- mime_anomaly_text = NULL;
- mime_boundary = NULL;
- mime_charset = NULL;
- mime_decoded_filename = NULL;
- mime_filename = NULL;
- mime_content_description = NULL;
- mime_content_disposition = NULL;
- mime_content_id = NULL;
- mime_content_transfer_encoding = 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
- * a "parent" field to my new boundary-context structure.)
- */
- if (context != NULL) {
- while(fgets(CS header, MIME_MAX_HEADER_SIZE, f) != NULL) {
- /* boundary line must start with 2 dashes */
- if (Ustrncmp(header,"--",2) == 0) {
- if (Ustrncmp((header+2),context->boundary,Ustrlen(context->boundary)) == 0) {
- /* found boundary */
- if (Ustrncmp((header+2+Ustrlen(context->boundary)),"--",2) == 0) {
- /* END boundary found */
- debug_printf("End boundary found %s\n", context->boundary);
- return rc;
- }
- else {
- debug_printf("Next part with boundary %s\n", context->boundary);
- };
- /* can't use break here */
- goto DECODE_HEADERS;
- }
- };
+ /* must find first free sequential filename */
+ for (gstring * g = string_get(64); result != -1; g->ptr = 0)
+ {
+ struct stat mystat;
+ g = string_fmt_append(g,
+ "%s/scan/%s/__rfc822_%05u", spool_directory, message_id, file_nr++);
+ /* security break */
+ if (file_nr >= 128)
+ goto NO_RFC822;
+ result = stat(CS (filename = string_from_gstring(g)), &mystat);
}
- /* Hit EOF or read error. Ugh. */
- debug_printf("Hit EOF ...\n");
- return rc;
- };
-
- DECODE_HEADERS:
- /* parse headers, set up expansion variables */
- while(mime_get_header(f,header)) {
- int i;
- /* loop through header list */
- 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;
- /* yes, grab the value (normalize to lower case)
- and copy to its corresponding expansion variable */
- while(*p != ';') {
- *p = tolower(*p);
- p++;
- };
- header_value_len = (p - (header + mime_header_list[i].namelen));
- header_value = (uschar *)malloc(header_value_len+1);
- memset(header_value,0,header_value_len+1);
- 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;
- /* yes, grab the value and copy to its corresponding expansion variable */
- while(*q != ';') q++;
- param_value_len = (q - (p + mime_parameter_list[j].namelen));
- param_value = (uschar *)malloc(param_value_len+1);
- 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);
- 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);
- goto NEXT_PARAM_SEARCH;
- };
- }
- /* There is something, but not one of our interesting parameters.
- Advance to the next semicolon */
- while(*p != ';') p++;
- p++;
- };
- };
- };
- };
-
- /* 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 */
+
+ rfc822name = filename;
+
+ /* decode RFC822 attachment */
+ mime_decoded_filename = NULL;
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);
-
+ mime_current_boundary = context ? context->boundary : NULL;
+ mime_decode(&rfc822name);
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) &&
- (Ustrncmp(mime_content_type,"multipart",9) == 0) ) {
- debug_printf("Entering multipart recursion, boundary '%s'\n", nested_context.boundary);
-
- if (context && context->context == MBC_ATTACHMENT)
- nested_context.context = MBC_ATTACHMENT;
- else if (!Ustrcmp(mime_content_type,"multipart/alternative")
- || !Ustrcmp(mime_content_type,"multipart/related"))
- nested_context.context = MBC_COVERLETTER_ALL;
- else
- nested_context.context = MBC_COVERLETTER_ONESHOT;
-
- rc = mime_acl_check(f, &nested_context, user_msgptr, log_msgptr);
- if (rc != OK) break;
- }
- else if ( (mime_content_type != NULL) &&
- (Ustrncmp(mime_content_type,"message/rfc822",14) == 0) ) {
- uschar *rfc822name = 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);
- file_nr++;
- /* security break */
- if (file_nr >= 128)
- goto NO_RFC822;
- result = stat(CS filename,&mystat);
+ if (!mime_decoded_filename) /* decoding failed */
+ {
+ log_write(0, LOG_MAIN,
+ "MIME acl condition warning - could not decode RFC822 MIME part to file.");
+ rc = DEFER;
+ goto out;
}
- while(result != -1);
-
- rfc822name = filename;
-
- /* decode RFC822 attachment */
- mime_decoded_filename = NULL;
- mime_stream = f;
- mime_current_boundary = context ? context->boundary : NULL;
- mime_decode(&rfc822name);
- mime_stream = NULL;
- mime_current_boundary = NULL;
- if (mime_decoded_filename == NULL) {
- /* decoding failed */
- log_write(0, LOG_MAIN,
- "mime_regex acl condition warning - could not decode RFC822 MIME part to file.");
- return DEFER;
- };
- 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;
+ mime_decoded_filename = NULL;
+ }
+
+NO_RFC822:
+ /* If the boundary of this instance is NULL, we are finished here */
+ if (!context) break;
+
+ if (context->context == MBC_COVERLETTER_ONESHOT)
+ context->context = MBC_ATTACHMENT;
+ }
+
+out:
+mime_vars_reset();
+return rc;
}
-#endif
+#endif /*WITH_CONTENT_SCAN*/
+
+/* vi: sw ai sw=2
+*/
git://git.exim.org / exim.git / blobdiff