summaryrefslogtreecommitdiffstats
path: root/g10/textfilter.c
diff options
context:
space:
mode:
Diffstat (limited to 'g10/textfilter.c')
-rw-r--r--g10/textfilter.c245
1 files changed, 245 insertions, 0 deletions
diff --git a/g10/textfilter.c b/g10/textfilter.c
new file mode 100644
index 0000000..3e68900
--- /dev/null
+++ b/g10/textfilter.c
@@ -0,0 +1,245 @@
+/* textfilter.c
+ * Copyright (C) 1998, 1999, 2000, 2001, 2004 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include "gpg.h"
+#include "../common/status.h"
+#include "../common/iobuf.h"
+#include "../common/util.h"
+#include "filter.h"
+#include "../common/i18n.h"
+#include "options.h"
+#include "../common/status.h"
+
+#ifdef HAVE_DOSISH_SYSTEM
+#define LF "\r\n"
+#else
+#define LF "\n"
+#endif
+
+#define MAX_LINELEN 19995 /* a little bit smaller than in armor.c */
+ /* to make sure that a warning is displayed while */
+ /* creating a message */
+
+static unsigned
+len_without_trailing_chars( byte *line, unsigned len, const char *trimchars )
+{
+ byte *p, *mark;
+ unsigned n;
+
+ for(mark=NULL, p=line, n=0; n < len; n++, p++ ) {
+ if( strchr( trimchars, *p ) ) {
+ if( !mark )
+ mark = p;
+ }
+ else
+ mark = NULL;
+ }
+
+ return mark? (mark - line) : len;
+}
+
+
+static int
+standard( text_filter_context_t *tfx, IOBUF a,
+ byte *buf, size_t size, size_t *ret_len)
+{
+ int rc=0;
+ size_t len = 0;
+ unsigned maxlen;
+
+ log_assert( size > 10 );
+ size -= 2; /* reserve 2 bytes to append CR,LF */
+ while( !rc && len < size ) {
+ int lf_seen;
+
+ while( len < size && tfx->buffer_pos < tfx->buffer_len )
+ buf[len++] = tfx->buffer[tfx->buffer_pos++];
+ if( len >= size )
+ continue;
+
+ /* read the next line */
+ maxlen = MAX_LINELEN;
+ tfx->buffer_pos = 0;
+ tfx->buffer_len = iobuf_read_line( a, &tfx->buffer,
+ &tfx->buffer_size, &maxlen );
+ if( !maxlen )
+ tfx->truncated++;
+ if( !tfx->buffer_len ) {
+ if( !len )
+ rc = -1; /* eof */
+ break;
+ }
+ lf_seen = tfx->buffer[tfx->buffer_len-1] == '\n';
+
+ /* The story behind this is that 2440 says that textmode
+ hashes should canonicalize line endings to CRLF and remove
+ spaces and tabs. 2440bis-12 says to just canonicalize to
+ CRLF. 1.4.0 was released using the bis-12 behavior, but it
+ was discovered that many mail clients do not canonicalize
+ PGP/MIME signature text appropriately (and were relying on
+ GnuPG to handle trailing spaces). So, we default to the
+ 2440 behavior, but use the 2440bis-12 behavior if the user
+ specifies --no-rfc2440-text. The default will be changed
+ at some point in the future when the mail clients have been
+ upgraded. Aside from PGP/MIME and broken mail clients,
+ this makes no difference to any signatures in the real
+ world except for a textmode detached signature. PGP always
+ used the 2440bis-12 behavior (ignoring 2440 itself), so
+ this actually makes us compatible with PGP textmode
+ detached signatures for the first time. */
+ if(opt.rfc2440_text)
+ tfx->buffer_len=trim_trailing_chars(tfx->buffer,tfx->buffer_len,
+ " \t\r\n");
+ else
+ tfx->buffer_len=trim_trailing_chars(tfx->buffer,tfx->buffer_len,
+ "\r\n");
+
+ if( lf_seen ) {
+ tfx->buffer[tfx->buffer_len++] = '\r';
+ tfx->buffer[tfx->buffer_len++] = '\n';
+ }
+ }
+ *ret_len = len;
+ return rc;
+}
+
+
+/****************
+ * The filter is used to make canonical text: Lines are terminated by
+ * CR, LF, trailing white spaces are removed.
+ */
+int
+text_filter( void *opaque, int control,
+ IOBUF a, byte *buf, size_t *ret_len)
+{
+ size_t size = *ret_len;
+ text_filter_context_t *tfx = opaque;
+ int rc=0;
+
+ if( control == IOBUFCTRL_UNDERFLOW ) {
+ rc = standard( tfx, a, buf, size, ret_len );
+ }
+ else if( control == IOBUFCTRL_FREE ) {
+ if( tfx->truncated )
+ log_error(_("can't handle text lines longer than %d characters\n"),
+ MAX_LINELEN );
+ xfree( tfx->buffer );
+ tfx->buffer = NULL;
+ }
+ else if( control == IOBUFCTRL_DESC )
+ mem2str (buf, "text_filter", *ret_len);
+ return rc;
+}
+
+
+/****************
+ * Copy data from INP to OUT and do some escaping if requested.
+ * md is updated as required by rfc2440
+ */
+int
+copy_clearsig_text( IOBUF out, IOBUF inp, gcry_md_hd_t md,
+ int escape_dash, int escape_from)
+{
+ unsigned int maxlen;
+ byte *buffer = NULL; /* malloced buffer */
+ unsigned int bufsize = 0; /* and size of this buffer */
+ unsigned int n;
+ int truncated = 0;
+ int pending_lf = 0;
+
+ if( !escape_dash )
+ escape_from = 0;
+
+ write_status_begin_signing (md);
+
+ for(;;) {
+ maxlen = MAX_LINELEN;
+ n = iobuf_read_line( inp, &buffer, &bufsize, &maxlen );
+ if( !maxlen )
+ truncated++;
+
+ if( !n )
+ break; /* read_line has returned eof */
+
+ /* update the message digest */
+ if( escape_dash ) {
+ if( pending_lf ) {
+ gcry_md_putc ( md, '\r' );
+ gcry_md_putc ( md, '\n' );
+ }
+ gcry_md_write ( md, buffer,
+ len_without_trailing_chars (buffer, n, " \t\r\n"));
+ }
+ else
+ gcry_md_write ( md, buffer, n );
+ pending_lf = buffer[n-1] == '\n';
+
+ /* write the output */
+ if( ( escape_dash && *buffer == '-')
+ || ( escape_from && n > 4 && !memcmp(buffer, "From ", 5 ) ) ) {
+ iobuf_put( out, '-' );
+ iobuf_put( out, ' ' );
+ }
+
+#if 0 /*defined(HAVE_DOSISH_SYSTEM)*/
+ /* We don't use this anymore because my interpretation of rfc2440 7.1
+ * is that there is no conversion needed. If one decides to
+ * clearsign a unix file on a DOS box he will get a mixed line endings.
+ * If at some point it turns out, that a conversion is a nice feature
+ * we can make an option out of it.
+ */
+ /* make sure the lines do end in CR,LF */
+ if( n > 1 && ( (buffer[n-2] == '\r' && buffer[n-1] == '\n' )
+ || (buffer[n-2] == '\n' && buffer[n-1] == '\r'))) {
+ iobuf_write( out, buffer, n-2 );
+ iobuf_put( out, '\r');
+ iobuf_put( out, '\n');
+ }
+ else if( n && buffer[n-1] == '\n' ) {
+ iobuf_write( out, buffer, n-1 );
+ iobuf_put( out, '\r');
+ iobuf_put( out, '\n');
+ }
+ else
+ iobuf_write( out, buffer, n );
+
+#else
+ iobuf_write( out, buffer, n );
+#endif
+ }
+
+ /* at eof */
+ if( !pending_lf ) { /* make sure that the file ends with a LF */
+ iobuf_writestr( out, LF );
+ if( !escape_dash )
+ gcry_md_putc( md, '\n' );
+ }
+
+ if( truncated )
+ log_info(_("input line longer than %d characters\n"), MAX_LINELEN );
+
+ xfree (buffer);
+ return 0; /* okay */
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-21 09:03:18 +0000