[exim-cvs] cvs commit: exim/exim-doc/doc-txt ChangeLog exim…

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Autor: Nigel Metheringham
Fecha:  
A: exim-cvs
Asunto: [exim-cvs] cvs commit: exim/exim-doc/doc-txt ChangeLog exim/exim-src/src mime.c
nm4 2009/11/06 13:29:47 GMT

  Modified files:
    exim-doc/doc-txt     ChangeLog 
    exim-src/src         mime.c 
  Log:
  Base64 decode bug fixes.  Fixes: #39


  Revision  Changes    Path
  1.588     +3 -0      exim/exim-doc/doc-txt/ChangeLog
  1.16      +147 -151  exim/exim-src/src/mime.c


  Index: ChangeLog
  ===================================================================
  RCS file: /home/cvs/exim/exim-doc/doc-txt/ChangeLog,v
  retrieving revision 1.587
  retrieving revision 1.588
  diff -u -r1.587 -r1.588
  --- ChangeLog    5 Nov 2009 19:40:51 -0000    1.587
  +++ ChangeLog    6 Nov 2009 13:29:47 -0000    1.588
  @@ -1,4 +1,4 @@
  -$Cambridge: exim/exim-doc/doc-txt/ChangeLog,v 1.587 2009/11/05 19:40:51 nm4 Exp $
  +$Cambridge: exim/exim-doc/doc-txt/ChangeLog,v 1.588 2009/11/06 13:29:47 nm4 Exp $


   Change log file for Exim from version 4.21
   -------------------------------------------
  @@ -148,6 +148,9 @@
   NM/34 Bugzilla 901: Fix sign/unsigned and UTF mistmatches
         Patch by Serge Demonchaux


  +NM/35 Bugzilla 39: Base64 decode bug fixes
  +      Patch by Jakob Hirsch
  +


Exim version 4.69
-----------------

  Index: mime.c
  ===================================================================
  RCS file: /home/cvs/exim/exim-src/src/mime.c,v
  retrieving revision 1.15
  retrieving revision 1.16
  diff -u -r1.15 -r1.16
  --- mime.c    5 Sep 2006 15:34:41 -0000    1.15
  +++ mime.c    6 Nov 2009 13:29:47 -0000    1.16
  @@ -1,4 +1,4 @@
  -/* $Cambridge: exim/exim-src/src/mime.c,v 1.15 2006/09/05 15:34:41 ph10 Exp $ */
  +/* $Cambridge: exim/exim-src/src/mime.c,v 1.16 2009/11/06 13:29:47 nm4 Exp $ */


   /*************************************************
   *     Exim - an Internet mail transport agent    *
  @@ -74,122 +74,156 @@
   }



+/* just dump MIME part without any decoding */
+static int mime_decode_asis(FILE* in, FILE* out, uschar* boundary)
+{
+ int len, size = 0;
+ uschar buffer[MIME_MAX_LINE_LENGTH];

  -uschar *mime_parse_line(uschar *buffer, uschar *data, uschar *encoding, int *num_decoded) {
  +  while(fgets(CS buffer, MIME_MAX_LINE_LENGTH, mime_stream) != NULL) {
  +    if (boundary != NULL
  +      && Ustrncmp(buffer, "--", 2) == 0
  +      && Ustrncmp((buffer+2), boundary, Ustrlen(boundary)) == 0
  +    )
  +      break;
  +
  +    len = Ustrlen(buffer);
  +    if (fwrite(buffer, 1, (size_t)len, out) < len)
  +      return -1;
  +    size += len;
  +  } /* while */
  +  return size;
  +}


  -  if (encoding == NULL) {
  -    /* no encoding type at all */
  -    NO_DECODING:
  -    memcpy(data, buffer, Ustrlen(buffer));
  -    data[(Ustrlen(buffer))] = 0;
  -    *num_decoded = Ustrlen(data);
  -    return data;
  -  }
  -  else if (Ustrcmp(encoding,"base64") == 0) {
  -    uschar *p = buffer;
  -    int offset = 0;
  -
  -    /* ----- BASE64 ---------------------------------------------------- */
  -    /* NULL out '\r' and '\n' chars */
  -    while (Ustrrchr(p,'\r') != NULL) {
  -      *(Ustrrchr(p,'\r')) = '\0';
  -    };
  -    while (Ustrrchr(p,'\n') != NULL) {
  -      *(Ustrrchr(p,'\n')) = '\0';
  -    };


  -    while (*(p+offset) != '\0') {
  -      /* hit illegal char ? */
  -      if (mime_b64[*(p+offset)] == 128) {
  +/* decode base64 MIME part */
  +static int mime_decode_base64(FILE* in, FILE* out, uschar* boundary)
  +{
  +  uschar ibuf[MIME_MAX_LINE_LENGTH], obuf[MIME_MAX_LINE_LENGTH];
  +  uschar *ipos, *opos;
  +  size_t len, size = 0;
  +  int bytestate = 0;
  +
  +  opos = obuf;
  +
  +  while (fgets(ibuf, MIME_MAX_LINE_LENGTH, in) != NULL)
  +  {
  +    if (boundary != NULL
  +      && Ustrncmp(ibuf, "--", 2) == 0
  +      && Ustrncmp((ibuf+2), boundary, Ustrlen(boundary)) == 0
  +    )
  +      break;
  +
  +    for (ipos = ibuf ; *ipos != '\r' && *ipos != '\n' && *ipos != 0; ++ipos) {
  +      /* skip padding */
  +      if (*ipos == '=') {
  +        ++bytestate;
  +        continue;
  +      }
  +      /* skip bad characters */
  +      if (mime_b64[*ipos] == 128) {
           mime_set_anomaly(MIME_ANOMALY_BROKEN_BASE64);
  -        offset++;
  +        continue;
         }
  -      else {
  -        *p = mime_b64[*(p+offset)];
  -        p++;
  -      };
  -    };
  -    *p = 255;
  +      /* simple state-machine */
  +      switch((bytestate++) & 3) {
  +        case 0:
  +          *opos = mime_b64[*ipos] << 2;
  +           break;
  +        case 1:
  +          *opos |= mime_b64[*ipos] >> 4;
  +          ++opos;
  +          *opos = mime_b64[*ipos] << 4;
  +          break;
  +        case 2:
  +          *opos |= mime_b64[*ipos] >> 2;
  +          ++opos;
  +          *opos = mime_b64[*ipos] << 6;
  +          break;
  +        case 3:
  +          *opos |= mime_b64[*ipos];
  +          ++opos;
  +          break;
  +      } /* switch */
  +    } /* for */
  +    /* something to write? */
  +    len = opos - obuf;
  +    if (len > 0) {
  +      if (fwrite(obuf, 1, len, out) != len)
  +        return -1; /* error */
  +      size += len;
  +      /* copy incomplete last byte to start of obuf, where we continue */
  +      if (bytestate & 3 != 0)
  +        *obuf = *opos;
  +      opos = obuf;
  +    }
  +  } /* while */


  -    /* line is translated, start bit shifting */
  -    p = buffer;
  -    *num_decoded = 0;
  -    while(*p != 255) {
  -      uschar tmp_c;
  +  /* write out last byte if it was incomplete */
  +  if (bytestate & 3) {
  +      if (fwrite(obuf, 1, 1, out) != 1)
  +          return -1;
  +      ++size;
  +  }


  -      /* byte 0 ---------------------- */
  -      if (*(p+1) == 255) {
  -        break;
  -      }
  -      data[(*num_decoded)] = *p;
  -      data[(*num_decoded)] <<= 2;
  -      tmp_c = *(p+1);
  -      tmp_c >>= 4;
  -      data[(*num_decoded)] |= tmp_c;
  -      (*num_decoded)++;
  -      p++;
  -      /* byte 1 ---------------------- */
  -      if (*(p+1) == 255) {
  -        break;
  -      }
  -      data[(*num_decoded)] = *p;
  -      data[(*num_decoded)] <<= 4;
  -      tmp_c = *(p+1);
  -      tmp_c >>= 2;
  -      data[(*num_decoded)] |= tmp_c;
  -      (*num_decoded)++;
  -      p++;
  -      /* byte 2 ---------------------- */
  -      if (*(p+1) == 255) {
  -        break;
  -      }
  -      data[(*num_decoded)] = *p;
  -      data[(*num_decoded)] <<= 6;
  -      data[(*num_decoded)] |= *(p+1);
  -      (*num_decoded)++;
  -      p+=2;
  +  return size;
  +}


  -    };
  -    return data;
  -    /* ----------------------------------------------------------------- */
  -  }
  -  else if (Ustrcmp(encoding,"quoted-printable") == 0) {
  -    uschar *p = buffer;


  -    /* ----- QP -------------------------------------------------------- */
  -    *num_decoded = 0;
  -    while (*p != 0) {
  -      if (*p == '=') {
  +/* decode quoted-printable MIME part */
  +static int mime_decode_qp(FILE* in, FILE* out, uschar* boundary)
  +{
  +  uschar ibuf[MIME_MAX_LINE_LENGTH], obuf[MIME_MAX_LINE_LENGTH];
  +  uschar *ipos, *opos;
  +  size_t len, size = 0;
  +
  +  while (fgets(CS ibuf, MIME_MAX_LINE_LENGTH, in) != NULL)
  +  {
  +    if (boundary != NULL
  +      && Ustrncmp(ibuf, "--", 2) == 0
  +      && Ustrncmp((ibuf+2), boundary, Ustrlen(boundary)) == 0
  +    )
  +      break; /* todo: check for missing boundary */
  +
  +    ipos = ibuf;
  +    opos = obuf;
  +
  +    while (*ipos != 0) {
  +      if (*ipos == '=') {
           int decode_qp_result;


  -        p = mime_decode_qp_char(p,&decode_qp_result);
  +        ipos = mime_decode_qp_char(ipos, &decode_qp_result);


           if (decode_qp_result == -2) {
  -          /* Error from decoder. p is unchanged. */
  +          /* Error from decoder. ipos is unchanged. */
             mime_set_anomaly(MIME_ANOMALY_BROKEN_QP);
  -          data[(*num_decoded)] = '=';
  -          (*num_decoded)++;
  -          p++;
  +          *opos = '=';
  +          ++opos;
  +          ++ipos;
           }
           else if (decode_qp_result == -1) {
             break;
           }
           else if (decode_qp_result >= 0) {
  -          data[(*num_decoded)] = decode_qp_result;
  -          (*num_decoded)++;
  -        };
  +          *opos = decode_qp_result;
  +          ++opos;
  +        }
         }
         else {
  -        data[(*num_decoded)] = *p;
  -        (*num_decoded)++;
  -        p++;
  -      };
  -    };
  -    return data;
  -    /* ----------------------------------------------------------------- */
  +        *opos = *ipos;
  +        ++opos;
  +        ++ipos;
  +      }
  +    }
  +    /* something to write? */
  +    len = opos - obuf;
  +    if (len > 0) {
  +      if (fwrite(obuf, 1, len, out) != len)
  +        return -1; /* error */
  +      size += len;
  +    }
     }
  -  /* unknown encoding type, just dump as-is */
  -  else goto NO_DECODING;
  +  return size;
   }



  @@ -238,10 +272,9 @@
     uschar option_buffer[1024];
     uschar decode_path[1024];
     FILE *decode_file = NULL;
  -  uschar *buffer = NULL;
  -  uschar *decode_buffer = NULL;
     long f_pos = 0;
     unsigned int size_counter = 0;
  +  int (*decode_function)(FILE*, FILE*, uschar*);


     if (mime_stream == NULL)
       return FAIL;
  @@ -251,21 +284,6 @@
     /* build default decode path (will exist since MBOX must be spooled up) */
     (void)string_format(decode_path,1024,"%s/scan/%s",spool_directory,message_id);


  -  /* reserve a line and decoder buffer to work in */
  -  buffer = (uschar *)malloc(MIME_MAX_LINE_LENGTH+1);
  -  if (buffer == NULL) {
  -    log_write(0, LOG_PANIC,
  -                 "decode ACL condition: can't allocate %d bytes of memory.", MIME_MAX_LINE_LENGTH+1);
  -    return DEFER;
  -  };
  -
  -  decode_buffer = (uschar *)malloc(MIME_MAX_LINE_LENGTH+1);
  -  if (decode_buffer == NULL) {
  -    log_write(0, LOG_PANIC,
  -                 "decode ACL condition: can't allocate %d bytes of memory.", MIME_MAX_LINE_LENGTH+1);
  -    return DEFER;
  -  };
  -
     /* try to find 1st option */
     if ((option = string_nextinlist(&list, &sep,
                                     option_buffer,
  @@ -306,50 +324,28 @@
     if (decode_file == NULL)
       return DEFER;


  -  /* read data linewise and dump it to the file,
  -     while looking for the current boundary */
  -  while(fgets(CS buffer, MIME_MAX_LINE_LENGTH, mime_stream) != NULL) {
  -    uschar *decoded_line = NULL;
  -    int decoded_line_length = 0;
  -
  -    if (mime_current_boundary != NULL) {
  -      /* boundary line must start with 2 dashes */
  -      if (Ustrncmp(buffer,"--",2) == 0) {
  -        if (Ustrncmp((buffer+2),mime_current_boundary,Ustrlen(mime_current_boundary)) == 0)
  -          break;
  -      };
  -    };
  -
  -    decoded_line = mime_parse_line(buffer, decode_buffer, mime_content_transfer_encoding, &decoded_line_length);
  -
  -    /* write line to decode file */
  -    if (fwrite(decoded_line, 1, decoded_line_length, decode_file) < decoded_line_length) {
  -      /* error/short write */
  -      clearerr(mime_stream);
  -      fseek(mime_stream,f_pos,SEEK_SET);
  -      return DEFER;
  -    };
  -    size_counter += decoded_line_length;
  -
  -    if (size_counter > 1023) {
  -      if ((mime_content_size + (size_counter / 1024)) < 65535)
  -        mime_content_size += (size_counter / 1024);
  -      else
  -        mime_content_size = 65535;
  -      size_counter = (size_counter % 1024);
  -    };
  -
  -  }
  +  /* decode according to mime type */
  +  if (mime_content_transfer_encoding == NULL)
  +    /* no encoding, dump as-is */
  +    decode_function = mime_decode_asis;
  +  else if (Ustrcmp(mime_content_transfer_encoding, "base64") == 0)
  +    decode_function = mime_decode_base64;
  +  else if (Ustrcmp(mime_content_transfer_encoding, "quoted-printable") == 0)
  +    decode_function = mime_decode_qp;
  +  else
  +    /* unknown encoding type, just dump as-is */
  +    decode_function = mime_decode_asis;


- (void)fclose(decode_file);
+ size_counter = decode_function(mime_stream, decode_file, mime_current_boundary);

     clearerr(mime_stream);
  -  fseek(mime_stream,f_pos,SEEK_SET);
  +  fseek(mime_stream, f_pos, SEEK_SET);


  -  /* round up remaining size bytes to one k */
  -  if (size_counter) {
  -    mime_content_size++;
  -  };
  +  if (size_counter < 0 || fclose(decode_file) != 0)
  +    return DEFER;
  +
  +  /* round up to the next KiB */
  +  mime_content_size = (size_counter + 1023) / 1024;


     return OK;
   }