Unbreak FreeBSD build

[exim.git] / src / src / mime.c

diff --git a/src/src/mime.c b/src/src/mime.c
index c215b7bcf159d430f6f631a34a2b6fb2a4ab92a2..c1921992e61b65daa81e75963c8c8b131cf2a93e 100644 (file)
--- a/src/src/mime.c
+++ b/src/src/mime.c
@@ -1,31 +1,60 @@
-/* $Cambridge: exim/src/src/mime.c,v 1.14 2006/02/22 14:46:44 ph10 Exp $ */
-

 /*************************************************
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
 /*************************************************
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 

-/* Copyright (c) Tom Kistner <tom@duncanthrax.net> 2004 */
-/* License: GPL */
+/*
+ * Copyright (c) The Exim Maintainers 2015 - 2022
+ * Copyright (c) Tom Kistner <tom@duncanthrax.net> 2004 - 2015
+ * License: GPL
+ */

 
 #include "exim.h"
 
 #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;
 
 #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
 /*************************************************
 * 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 = US 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;

 }
 
 
 }
 
 


@@ -41,692 +70,734 @@ void mime_set_anomaly(int level, char *text) {
            0-255 - char to write
 */
 
            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);
-}
+static uschar *
+mime_decode_qp_char(uschar *qp_p, int *c)
+{
+uschar *initial_pos = qp_p;

 
 

-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 */
+qp_p++;

 
 

-  /* advance one char */
+/* 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++;
   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;
-  }
-  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 */
-    *c = -1;
-    return qp_p;
+  *c |= isdigit(*qp_p) ? *qp_p - '0' : toupper(*qp_p) - 'A' + 10;
+  return qp_p + 1;

   }
   }

-  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;
-    };
+
+/* tab or whitespace may follow just ignore it if it precedes \n */
+while (*qp_p == '\t' || *qp_p == ' ' || *qp_p == '\r')
+  qp_p++;
+
+if (*qp_p == '\n')     /* hit soft line break */
+  {
+  *c = -1;
+  return qp_p;

   }
   }

-  else {
-    /* illegal char */
-    *c = -2;
-    return initial_pos;
-  };
+
+/* illegal char here */
+*c = -2;
+return initial_pos;

 }
 
 
 }
 
 

-uschar *mime_parse_line(uschar *buffer, uschar *data, uschar *encoding, int *num_decoded) {
+/* 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;
+}

 
 

-  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) {
-        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;
+
+
+/* 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;

       }
       }

-      data[(*num_decoded)] = *p;
-      data[(*num_decoded)] <<= 6;
-      data[(*num_decoded)] |= *(p+1);
-      (*num_decoded)++;
-      p+=2;
-
-    };
-    return data;
-    /* ----------------------------------------------------------------- */
+    else
+      *opos++ = *ipos++;
+    }
+  /* something to write? */
+  len = opos - obuf;
+  if (len > 0)
+    {
+    if (fwrite(obuf, 1, len, out) != len) return -1; /* error */
+    size += len;
+    }

   }
   }

-  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 {
-        data[(*num_decoded)] = *p;
-        (*num_decoded)++;
-        p++;
-      };
-    };
-    return data;
-    /* ----------------------------------------------------------------- */
+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);

   }
   }

-  /* unknown encoding type, just dump as-is */
-  else goto NO_DECODING;
+
+return modefopen(mime_decoded_filename, "wb+", SPOOL_MODE);

 }
 
 
 }
 
 

-FILE *mime_get_decode_file(uschar *pname, uschar *fname) {
-  FILE *f = NULL;
-  uschar *filename;
+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;
+
+  if (option[0] == '/')
+    {
+    struct stat statbuf;

 
 

-  filename = (uschar *)malloc(2048);
+    memset(&statbuf,0,sizeof(statbuf));

 
 

-  if ((pname != NULL) && (fname != NULL)) {
-    (void)string_format(filename, 2048, "%s/%s", pname, fname);
-    f = modefopen(filename,"wb+",SPOOL_MODE);
+    /* 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 (pname == NULL) {
-    f = modefopen(fname,"wb+",SPOOL_MODE);
+else
+  {
+  /* no option? patch default path */
+DEFAULT_PATH:
+  decode_file = mime_get_decode_file(decode_path, NULL);

   }
   }

-  else if (fname == NULL) {
-    int file_nr = 0;
-    int result = 0;

 
 

-    /* must find first free sequential filename */
-    do {
-      struct stat mystat;
-      (void)string_format(filename,2048,"%s/%s-%05u", pname, message_id, file_nr);
-      file_nr++;
-      /* security break */
-      if (file_nr >= 1024)
-        break;
-      result = stat(CS filename,&mystat);
-    }
-    while(result != -1);
-    f = modefopen(filename,"wb+",SPOOL_MODE);
-  };
+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 */

 
 

-  /* set expansion variable */
-  mime_decoded_filename = filename;
+size_counter = decode_function(mime_stream, decode_file, mime_current_boundary);

 
 

-  return f;
+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;

 }
 
 
 }
 
 

-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;
-  uschar *decode_buffer = NULL;
-  long f_pos = 0;
-  unsigned int size_counter = 0;
+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);
+      }
+    /* end of the header, terminate with ';' */
+    c = ';';
+    done = 1;
+    }
+
+  /* skip control characters */
+  if (c < 32) continue;

 
 

-  if (mime_stream == NULL)
-    return FAIL;
+  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;

 
 

-  f_pos = ftell(mime_stream);
-
-  /* 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,
-                                  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 (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
-      /* assume file name only, use default path */
-      decode_file = mime_get_decode_file(decode_path, option);
-  }

   else
   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, 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);
-    };
+    {
+    /* -------- 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;
+      }
+    else if (c == '(')
+      {
+      header_open_brackets++;
+      continue;
+      }
+    else if ((c == ')') && header_open_brackets)
+      {
+      header_open_brackets--;
+      continue;
+      }
+    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;

   }
 
   }
 

-  (void)fclose(decode_file);
+if ((num_copied > 0) && (header[num_copied-1] != ';'))
+  header[num_copied-1] = ';';

 
 

-  clearerr(mime_stream);
-  fseek(mime_stream,f_pos,SEEK_SET);
+/* 0-terminate */
+header[num_copied] = '\0';
+
+/* return 0 for EOF or empty line */
+return c == EOF || num_copied == 1 ? 0 : 1;
+}

 
 

-  /* round up remaining size bytes to one k */
-  if (size_counter) {
-    mime_content_size++;
-  };

 
 

-  return OK;
+/* 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;

 }
 
 }
 

-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;
-        (void)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;
-      };
-      /* -------------------------------- */
+
+/* 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 {
-      /* -------- 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;
-      }
-      else if (c == '(') {
-        header_open_brackets++;
-        continue;
-      }
-      else if ((c == ')') && header_open_brackets) {
-        header_open_brackets--;
-        continue;
-      }
-      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 ((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;

   else
   else

-    return 1;
+    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 " */
+    }
+  else
+    s++;
+return s;
+}

 
 

-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 */
-  header = (uschar *)malloc(MIME_MAX_HEADER_SIZE+1);
-  if (header == NULL) {
-    log_write(0, LOG_PANIC,
-                 "MIME ACL: 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     = 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;
-
-    /*
-    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;
-          }
-        };
-      }
+
+static uschar *
+rfc2231_to_2047(const uschar * fname, const uschar * charset, int * len)
+{
+gstring * val = string_catn(NULL, US"=?", 2);
+uschar c;
+
+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
+    val = string_catn(val, fname++, 1);
+
+val = string_catn(val, US"?=", 2);
+*len = val->ptr;
+return string_from_gstring(val);
+}
+
+
+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, GET_TAINTED);
+
+/* 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. */
       /* Hit EOF or read error. Ugh. */

-      debug_printf("Hit EOF ...\n");
+      DEBUG(D_acl) debug_printf_indent("MIME: Hit EOF ...\n");

       return rc;
       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, check_rfc2047_length, NULL, 32, &param_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 */
-    mime_stream = f;
-    mime_current_boundary = context ? context->boundary : 0;
+      }

 
 

-    /* Note the context */
-    mime_is_coverletter = !(context && context->context == MBC_ATTACHMENT);
+    /* 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;
+      }
+    }

 
 

-    /* call ACL handling function */
-    rc = acl_check(ACL_WHERE_MIME, NULL, acl, user_msgptr, log_msgptr);
+  /* 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);
+         }
+       }
+      }

 
 

-    mime_stream = NULL;
-    mime_current_boundary = NULL;
+  /* set additional flag variables (easier access) */
+  if (  mime_content_type
+     && Ustrncmp(mime_content_type,"multipart",9) == 0
+     )
+    mime_is_multipart = 1;

 
 

-    if (rc != OK) break;
+  /* 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 != 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(acl, f, &nested_context, user_msgptr, log_msgptr);
-      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 != 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;
-        (void)string_format(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);
+  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;
+
+    /* 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);
+      }
+
+    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)                /* 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
+*/