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gpg: Detect already compressed data also when using a pipe.

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* common/iobuf.c (file_filter_ctx_t): Add fields for the peek feature.
(file_filter): Implement peeking.
(iobuf_ioctl): Add new IOBUF_IOCTL_PEEK.
* common/iobuf.h (IOBUF_IOCTL_PEEK, IOBUFCTRL_PEEK): New.
* common/miscellaneous.c (is_file_compressed): Rewrite.  Detect PDF.
* g10/encrypt.c (encrypt_simple): Peek before detecting compression.
(encrypt_crypt): Ditto.
* g10/sign.c (sign_file): Also detect already compressed data.

* g10/options.h (opt): Add explicit_compress_option.
* g10/gpg.c (main): Set opt.explicit_compress_option for -z.

--

Note that this patch also introduces a compression check for signing
which was never done in the past.

GnuPG-bug-id: 6332
Backported-from-master: 60963d98cfd8e60f88ee43c2d992f6dd3bbbd74c

Note that sign.c (sign_file) has been re-indented to ease future
backports.
This commit is contained in:
Werner Koch 2023-01-18 18:04:50 +01:00
parent ca822a2339
commit ce8ffd71b7
No known key found for this signature in database
GPG Key ID: E3FDFF218E45B72B
9 changed files with 491 additions and 347 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

97
common/iobuf.c
View File

@ -1,7 +1,7 @@
/* iobuf.c - File Handling for OpenPGP.
* Copyright (C) 1998, 1999, 2000, 2001, 2003, 2004, 2006, 2007, 2008,
* 2009, 2010, 2011 Free Software Foundation, Inc.
* Copyright (C) 2015 g10 Code GmbH
* Copyright (C) 2015, 2023 g10 Code GmbH
*
* This file is part of GnuPG.
*
@ -93,6 +93,9 @@ typedef struct
int no_cache;
int eof_seen;
int print_only_name; /* Flags indicating that fname is not a real file. */
char peeked[32]; /* Read ahead buffer. */
byte npeeked; /* Number of bytes valid in peeked. */
byte upeeked; /* Number of bytes used from peeked. */
char fname[1]; /* Name of the file. */
} file_filter_ctx_t;
@ -454,7 +457,16 @@ file_filter (void *opaque, int control, iobuf_t chain, byte * buf,
if (control == IOBUFCTRL_UNDERFLOW)
{
log_assert (size); /* We need a buffer. */
if (a->eof_seen)
if (a->npeeked > a->upeeked)
{
nbytes = a->npeeked - a->upeeked;
if (nbytes > size)
nbytes = size;
memcpy (buf, a->peeked + a->upeeked, nbytes);
a->upeeked += nbytes;
*ret_len = nbytes;
}
else if (a->eof_seen)
{
rc = -1;
*ret_len = 0;
@ -573,6 +585,68 @@ file_filter (void *opaque, int control, iobuf_t chain, byte * buf,
a->eof_seen = 0;
a->keep_open = 0;
a->no_cache = 0;
a->npeeked = 0;
a->upeeked = 0;
}
else if (control == IOBUFCTRL_PEEK)
{
/* Peek on the input. */
#ifdef HAVE_W32_SYSTEM
unsigned long nread;
nbytes = 0;
if (!ReadFile (f, a->peeked, sizeof a->peeked, &nread, NULL))
{
int ec = (int) GetLastError ();
if (ec != ERROR_BROKEN_PIPE)
{
rc = gpg_error_from_errno (ec);
log_error ("%s: read error: ec=%d\n", a->fname, ec);
}
a->npeeked = 0;
}
else if (!nread)
{
a->eof_seen = 1;
a->npeeked = 0;
}
else
{
a->npeeked = nread;
}
#else /* Unix */
int n;
peek_more:
do
{
n = read (f, a->peeked + a->npeeked, sizeof a->peeked - a->npeeked);
}
while (n == -1 && errno == EINTR);
if (n > 0)
{
a->npeeked += n;
if (a->npeeked < sizeof a->peeked)
goto peek_more;
}
else if (!n) /* eof */
{
a->eof_seen = 1;
}
else /* error */
{
rc = gpg_error_from_syserror ();
if (gpg_err_code (rc) != GPG_ERR_EPIPE)
log_error ("%s: read error: %s\n", a->fname, gpg_strerror (rc));
}
#endif /* Unix */
size = a->npeeked < size? a->npeeked : size;
memcpy (buf, a->peeked, size);
*ret_len = size;
rc = 0; /* Return success - the user needs to check ret_len. */
}
else if (control == IOBUFCTRL_DESC)
{
@ -1487,6 +1561,25 @@ iobuf_ioctl (iobuf_t a, iobuf_ioctl_t cmd, int intval, void *ptrval)
return fd_cache_synchronize (ptrval);
}
}
else if (cmd == IOBUF_IOCTL_PEEK)
{
/* Peek at a justed opened file. Use this only directly after a
* file has been opened for reading. Don't use it after you did
* a seek. This works only if just file filter has been
* pushed. Expects a buffer wit size INTVAL at PTRVAL and returns
* the number of bytes put into the buffer. */
if (DBG_IOBUF)
log_debug ("iobuf-%d.%d: ioctl '%s' peek\n",
a ? a->no : -1, a ? a->subno : -1, iobuf_desc (a, desc));
if (a->filter == file_filter && ptrval && intval)
{
file_filter_ctx_t *fcx = a->filter_ov;
size_t len = intval;
if (!file_filter (fcx, IOBUFCTRL_PEEK, NULL, ptrval, &len))
return (int)len;
}
}
return -1;

4
common/iobuf.h
View File

@ -106,6 +106,7 @@ enum
IOBUFCTRL_FLUSH = 4,
IOBUFCTRL_DESC = 5,
IOBUFCTRL_CANCEL = 6,
IOBUFCTRL_PEEK = 7,
IOBUFCTRL_USER = 16
};
@ -116,7 +117,8 @@ typedef enum
IOBUF_IOCTL_KEEP_OPEN = 1, /* Uses intval. */
IOBUF_IOCTL_INVALIDATE_CACHE = 2, /* Uses ptrval. */
IOBUF_IOCTL_NO_CACHE = 3, /* Uses intval. */
IOBUF_IOCTL_FSYNC = 4 /* Uses ptrval. */
IOBUF_IOCTL_FSYNC = 4, /* Uses ptrval. */
IOBUF_IOCTL_PEEK = 5 /* Uses intval and ptrval. */
} iobuf_ioctl_t;
enum iobuf_use

77
common/miscellaneous.c
View File

@ -466,7 +466,7 @@ decode_c_string (const char *src)
/* Check whether (BUF,LEN) is valid header for an OpenPGP compressed
* packet. LEN should be at least 6. */
static int
is_openpgp_compressed_packet (unsigned char *buf, size_t len)
is_openpgp_compressed_packet (const unsigned char *buf, size_t len)
{
int c, ctb, pkttype;
int lenbytes;
@ -508,63 +508,46 @@ is_openpgp_compressed_packet (unsigned char *buf, size_t len)
/*
* Check if the file is compressed.
* Check if the file is compressed. You need to pass the first bytes
* of the file as (BUF,BUFLEN). Returns true if the buffer seems to
* be compressed.
*/
int
is_file_compressed (const char *s, int *ret_rc)
is_file_compressed (const byte *buf, unsigned int buflen)
{
iobuf_t a;
byte buf[6];
int i;
int rc = 0;
int overflow;
int i;
struct magic_compress_s {
size_t len;
byte magic[4];
} magic[] = {
{ 3, { 0x42, 0x5a, 0x68, 0x00 } }, /* bzip2 */
{ 3, { 0x1f, 0x8b, 0x08, 0x00 } }, /* gzip */
{ 4, { 0x50, 0x4b, 0x03, 0x04 } }, /* (pk)zip */
};
struct magic_compress_s
{
byte len;
byte magic[5];
} magic[] =
{
{ 3, { 0x42, 0x5a, 0x68, 0x00 } }, /* bzip2 */
{ 3, { 0x1f, 0x8b, 0x08, 0x00 } }, /* gzip */
{ 4, { 0x50, 0x4b, 0x03, 0x04 } }, /* (pk)zip */
{ 5, { '%', 'P', 'D', 'F', '-'} } /* PDF */
};
if ( iobuf_is_pipe_filename (s) || !ret_rc )
return 0; /* We can't check stdin or no file was given */
a = iobuf_open( s );
if ( a == NULL ) {
*ret_rc = gpg_error_from_syserror ();
return 0;
}
iobuf_ioctl (a, IOBUF_IOCTL_NO_CACHE, 1, NULL);
if ( iobuf_get_filelength( a, &overflow ) < 6 && !overflow) {
*ret_rc = 0;
goto leave;
if ( buflen < 6 )
{
return 0; /* Too short to check - assume uncompressed. */
}
if ( iobuf_read( a, buf, 6 ) == -1 ) {
*ret_rc = a->error;
goto leave;
}
for ( i = 0; i < DIM( magic ); i++ ) {
if ( !memcmp( buf, magic[i].magic, magic[i].len ) ) {
*ret_rc = 0;
rc = 1;
goto leave;
for ( i = 0; i < DIM (magic); i++ )
{
if ( !memcmp( buf, magic[i].magic, magic[i].len ))
{
return 1; /* Is compressed. */
}
}
if (is_openpgp_compressed_packet (buf, 6))
{
*ret_rc = 0;
rc = 1;
}
if (buflen >= 6 && is_openpgp_compressed_packet (buf, buflen))
{
return 1; /* Already compressed. */
}
leave:
iobuf_close( a );
return rc;
return 0; /* Not detected as compressed. */
}

2
common/util.h
View File

@ -347,7 +347,7 @@ char *try_make_printable_string (const void *p, size_t n, int delim);
char *make_printable_string (const void *p, size_t n, int delim);
char *decode_c_string (const char *src);
int is_file_compressed (const char *s, int *ret_rc);
int is_file_compressed (const byte *buf, unsigned int buflen);
int match_multistr (const char *multistr,const char *match);

17
doc/gpg.texi
View File

@ -848,9 +848,10 @@ line.
@opindex keyedit:tsign
Make a trust signature. This is a signature that combines the notions
of certification (like a regular signature), and trust (like the
"trust" command). It is generally only useful in distinct communities
or groups. For more information please read the sections
``Trust Signature'' and ``Regular Expression'' in RFC-4880.
"trust" command). It is generally useful in distinct communities
or groups to implement the concept of a Trusted Introducer. For
more information please read the sections ``Trust Signature'' and
``Regular Expression'' in RFC-4880.
@end table
@c man:.RS
@ -1619,6 +1620,16 @@ for the BZIP2 compression algorithm (defaulting to 6 as well). This is a
different option from @option{--compress-level} since BZIP2 uses a
significant amount of memory for each additional compression level.
@option{-z} sets both. A value of 0 for @var{n} disables compression.
A value of -1 forces compression using the default level.
Except for the @option{--store} command compression is always used
unless @command{gpg} detects that the input is already compressed. To
inhibit the use of compression use @option{-z0}; to force compression
use @option{-z-1} or option @option{z} with another compression level
than the default as indicated by -1. Note that this overriding of the
default deection works only with @option{z} and not with the long
variant of this option.
@item --bzip2-decompress-lowmem
@opindex bzip2-decompress-lowmem

33
g10/encrypt.c
View File

@ -1,7 +1,7 @@
/* encrypt.c - Main encryption driver
* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
* 2006, 2009 Free Software Foundation, Inc.
* Copyright (C) 2016, 2022 g10 Code GmbH
* Copyright (C) 2016, 2022, 2023 g10 Code GmbH
*
* This file is part of GnuPG.
*
@ -17,6 +17,7 @@
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses/>.
* SPDX-License-Identifier: GPL-3.0-or-later
*/
#include <config.h>
@ -326,6 +327,8 @@ encrypt_simple (const char *filename, int mode, int use_seskey)
text_filter_context_t tfx;
progress_filter_context_t *pfx;
int do_compress = !!default_compress_algo();
char peekbuf[32];
int peekbuflen;
if (!gnupg_rng_is_compliant (opt.compliance))
{
@ -362,6 +365,14 @@ encrypt_simple (const char *filename, int mode, int use_seskey)
return rc;
}
peekbuflen = iobuf_ioctl (inp, IOBUF_IOCTL_PEEK, sizeof peekbuf, peekbuf);
if (peekbuflen < 0)
{
peekbuflen = 0;
if (DBG_FILTER)
log_debug ("peeking at input failed\n");
}
handle_progress (pfx, inp, filename);
if (opt.textmode)
@ -426,10 +437,11 @@ encrypt_simple (const char *filename, int mode, int use_seskey)
if (do_compress
&& cfx.dek
&& (cfx.dek->use_mdc || cfx.dek->use_aead)
&& is_file_compressed(filename, &rc))
&& !opt.explicit_compress_option
&& is_file_compressed (peekbuf, peekbuflen))
{
if (opt.verbose)
log_info(_("'%s' already compressed\n"), filename);
log_info(_("'%s' already compressed\n"), filename? filename: "[stdin]");
do_compress = 0;
}
@ -768,6 +780,8 @@ encrypt_crypt (ctrl_t ctrl, int filefd, const char *filename,
progress_filter_context_t *pfx;
PK_LIST pk_list;
int do_compress;
char peekbuf[32];
int peekbuflen;
if (filefd != -1 && filename)
return gpg_error (GPG_ERR_INV_ARG); /* Both given. */
@ -840,6 +854,14 @@ encrypt_crypt (ctrl_t ctrl, int filefd, const char *filename,
if (opt.verbose)
log_info (_("reading from '%s'\n"), iobuf_get_fname_nonnull (inp));
peekbuflen = iobuf_ioctl (inp, IOBUF_IOCTL_PEEK, sizeof peekbuf, peekbuf);
if (peekbuflen < 0)
{
peekbuflen = 0;
if (DBG_FILTER)
log_debug ("peeking at input failed\n");
}
handle_progress (pfx, inp, filename);
if (opt.textmode)
@ -874,10 +896,11 @@ encrypt_crypt (ctrl_t ctrl, int filefd, const char *filename,
if (do_compress
&& (cfx.dek->use_mdc || cfx.dek->use_aead)
&& is_file_compressed(filename, &rc2))
&& !opt.explicit_compress_option
&& is_file_compressed (peekbuf, peekbuflen))
{
if (opt.verbose)
log_info(_("'%s' already compressed\n"), filename);
log_info(_("'%s' already compressed\n"), filename? filename: "[stdin]");
do_compress = 0;
}
if (rc2)

1
g10/gpg.c
View File

@ -3126,6 +3126,7 @@ main (int argc, char **argv)
case oCompress:
/* this is the -z command line option */
opt.compress_level = opt.bz2_compress_level = pargs.r.ret_int;
opt.explicit_compress_option = 1;
break;
case oCompressLevel: opt.compress_level = pargs.r.ret_int; break;
case oBZ2CompressLevel: opt.bz2_compress_level = pargs.r.ret_int; break;

1
g10/options.h
View File

@ -92,6 +92,7 @@ struct
int force_ocb;
int cert_digest_algo;
int compress_algo;
int explicit_compress_option; /* A compress option was explicitly given. */
int compress_level;
int bz2_compress_level;
int bz2_decompress_lowmem;

606
g10/sign.c
View File

@ -921,62 +921,68 @@ int
sign_file (ctrl_t ctrl, strlist_t filenames, int detached, strlist_t locusr,
int encryptflag, strlist_t remusr, const char *outfile )
{
const char *fname;
armor_filter_context_t *afx;
compress_filter_context_t zfx;
md_filter_context_t mfx;
text_filter_context_t tfx;
progress_filter_context_t *pfx;
encrypt_filter_context_t efx;
IOBUF inp = NULL, out = NULL;
PACKET pkt;
int rc = 0;
PK_LIST pk_list = NULL;
SK_LIST sk_list = NULL;
SK_LIST sk_rover = NULL;
int multifile = 0;
u32 duration=0;
const char *fname;
armor_filter_context_t *afx;
compress_filter_context_t zfx;
md_filter_context_t mfx;
text_filter_context_t tfx;
progress_filter_context_t *pfx;
encrypt_filter_context_t efx;
iobuf_t inp = NULL;
iobuf_t out = NULL;
PACKET pkt;
int rc = 0;
PK_LIST pk_list = NULL;
SK_LIST sk_list = NULL;
SK_LIST sk_rover = NULL;
int multifile = 0;
u32 duration=0;
char peekbuf[32];
int peekbuflen = 0;
pfx = new_progress_context ();
afx = new_armor_context ();
memset( &zfx, 0, sizeof zfx);
memset( &mfx, 0, sizeof mfx);
memset( &efx, 0, sizeof efx);
efx.ctrl = ctrl;
init_packet( &pkt );
if( filenames ) {
fname = filenames->d;
multifile = !!filenames->next;
pfx = new_progress_context ();
afx = new_armor_context ();
memset (&zfx, 0, sizeof zfx);
memset (&mfx, 0, sizeof mfx);
memset (&efx, 0, sizeof efx);
efx.ctrl = ctrl;
init_packet (&pkt);
if (filenames)
{
fname = filenames->d;
multifile = !!filenames->next;
}
else
fname = NULL;
else
fname = NULL;
if( fname && filenames->next && (!detached || encryptflag) )
log_bug("multiple files can only be detached signed");
if (fname && filenames->next && (!detached || encryptflag))
log_bug ("multiple files can only be detached signed");
if(encryptflag==2
&& (rc=setup_symkey(&efx.symkey_s2k,&efx.symkey_dek)))
goto leave;
if (encryptflag == 2
&& (rc = setup_symkey (&efx.symkey_s2k,&efx.symkey_dek)))
goto leave;
if (opt.ask_sig_expire && !opt.batch)
duration = ask_expire_interval(1,opt.def_sig_expire);
else
duration = parse_expire_string(opt.def_sig_expire);
if (opt.ask_sig_expire && !opt.batch)
duration = ask_expire_interval(1,opt.def_sig_expire);
else
duration = parse_expire_string(opt.def_sig_expire);
/* Note: In the old non-agent version the following call used to
unprotect the secret key. This is now done on demand by the agent. */
if( (rc = build_sk_list (ctrl, locusr, &sk_list, PUBKEY_USAGE_SIG )) )
goto leave;
/* Note: In the old non-agent version the following call used to
unprotect the secret key. This is now done on demand by the agent. */
if ((rc = build_sk_list (ctrl, locusr, &sk_list, PUBKEY_USAGE_SIG )))
goto leave;
if (encryptflag
&& (rc=build_pk_list (ctrl, remusr, &pk_list)))
goto leave;
if (encryptflag
&& (rc=build_pk_list (ctrl, remusr, &pk_list)))
goto leave;
/* prepare iobufs */
if( multifile ) /* have list of filenames */
inp = NULL; /* we do it later */
else {
/* Prepare iobufs. */
if (multifile) /* have list of filenames */
inp = NULL; /* we do it later */
else
{
inp = iobuf_open(fname);
if (inp && is_secured_file (iobuf_get_fd (inp)))
{
@ -992,274 +998,298 @@ sign_file (ctrl_t ctrl, strlist_t filenames, int detached, strlist_t locusr,
goto leave;
}
handle_progress (pfx, inp, fname);
}
if( outfile ) {
if (is_secured_filename ( outfile )) {
out = NULL;
gpg_err_set_errno (EPERM);
peekbuflen = iobuf_ioctl (inp, IOBUF_IOCTL_PEEK, sizeof peekbuf, peekbuf);
if (peekbuflen < 0)
{
peekbuflen = 0;
if (DBG_FILTER)
log_debug ("peeking at input failed\n");
}
else
out = iobuf_create (outfile, 0);
if( !out )
{
rc = gpg_error_from_syserror ();
log_error(_("can't create '%s': %s\n"), outfile, strerror(errno) );
goto leave;
}
else if( opt.verbose )
log_info(_("writing to '%s'\n"), outfile );
handle_progress (pfx, inp, fname);
}
else if( (rc = open_outfile (-1, fname,
opt.armor? 1: detached? 2:0, 0, &out)))
goto leave;
/* prepare to calculate the MD over the input */
if( opt.textmode && !outfile && !multifile )
{
memset( &tfx, 0, sizeof tfx);
iobuf_push_filter( inp, text_filter, &tfx );
}
if (outfile)
{
if (is_secured_filename ( outfile ))
{
out = NULL;
gpg_err_set_errno (EPERM);
}
else
out = iobuf_create (outfile, 0);
if (!out)
{
rc = gpg_error_from_syserror ();
log_error(_("can't create '%s': %s\n"), outfile, strerror(errno) );
goto leave;
}
else if (opt.verbose)
log_info (_("writing to '%s'\n"), outfile);
}
else if ((rc = open_outfile (-1, fname,
opt.armor? 1: detached? 2:0, 0, &out)))
goto leave;
if ( gcry_md_open (&mfx.md, 0, 0) )
BUG ();
if (DBG_HASHING)
gcry_md_debug (mfx.md, "sign");
/* Prepare to calculate the MD over the input. */
if (opt.textmode && !outfile && !multifile)
{
memset( &tfx, 0, sizeof tfx);
iobuf_push_filter( inp, text_filter, &tfx );
}
/* If we're encrypting and signing, it is reasonable to pick the
hash algorithm to use out of the recipient key prefs. This is
best effort only, as in a DSA2 and smartcard world there are
cases where we cannot please everyone with a single hash (DSA2
wants >160 and smartcards want =160). In the future this could
be more complex with different hashes for each sk, but the
current design requires a single hash for all SKs. */
if(pk_list)
{
if(opt.def_digest_algo)
{
if(!opt.expert &&
select_algo_from_prefs(pk_list,PREFTYPE_HASH,
opt.def_digest_algo,
NULL)!=opt.def_digest_algo)
log_info(_("WARNING: forcing digest algorithm %s (%d)"
" violates recipient preferences\n"),
gcry_md_algo_name (opt.def_digest_algo),
opt.def_digest_algo );
}
else
{
int algo;
int conflict = 0;
struct pref_hint hint = { 0 };
if (gcry_md_open (&mfx.md, 0, 0))
BUG ();
if (DBG_HASHING)
gcry_md_debug (mfx.md, "sign");
/* Of course, if the recipient asks for something
unreasonable (like the wrong hash for a DSA key) then
don't do it. Check all sk's - if any are DSA or live
on a smartcard, then the hash has restrictions and we
may not be able to give the recipient what they want.
For DSA, pass a hint for the largest q we have. Note
that this means that a q>160 key will override a q=160
key and force the use of truncation for the q=160 key.
The alternative would be to ignore the recipient prefs
completely and get a different hash for each DSA key in
hash_for(). The override behavior here is more or less
reasonable as it is under the control of the user which
keys they sign with for a given message and the fact
that the message with multiple signatures won't be
usable on an implementation that doesn't understand
DSA2 anyway. */
/* If we're encrypting and signing, it is reasonable to pick the
* hash algorithm to use out of the recipient key prefs. This is
* best effort only, as in a DSA2 and smartcard world there are
* cases where we cannot please everyone with a single hash (DSA2
* wants >160 and smartcards want =160). In the future this could
* be more complex with different hashes for each sk, but the
* current design requires a single hash for all SKs. */
if (pk_list)
{
if (opt.def_digest_algo)
{
if (!opt.expert &&
select_algo_from_prefs(pk_list,PREFTYPE_HASH,
opt.def_digest_algo,
NULL)!=opt.def_digest_algo)
log_info (_("WARNING: forcing digest algorithm %s (%d)"
" violates recipient preferences\n"),
gcry_md_algo_name (opt.def_digest_algo),
opt.def_digest_algo );
}
else
{
int algo;
int conflict = 0;
struct pref_hint hint = { 0 };
for (sk_rover = sk_list; sk_rover; sk_rover = sk_rover->next )
{
if (sk_rover->pk->pubkey_algo == PUBKEY_ALGO_DSA
|| sk_rover->pk->pubkey_algo == PUBKEY_ALGO_ECDSA)
{
int temp_hashlen = (gcry_mpi_get_nbits
(sk_rover->pk->pkey[1]));
/* Of course, if the recipient asks for something
* unreasonable (like the wrong hash for a DSA key) then
* don't do it. Check all sk's - if any are DSA or live
* on a smartcard, then the hash has restrictions and we
* may not be able to give the recipient what they want.
* For DSA, pass a hint for the largest q we have. Note
* that this means that a q>160 key will override a q=160
* key and force the use of truncation for the q=160 key.
* The alternative would be to ignore the recipient prefs
* completely and get a different hash for each DSA key in
* hash_for(). The override behavior here is more or less
* reasonable as it is under the control of the user which
* keys they sign with for a given message and the fact
* that the message with multiple signatures won't be
* usable on an implementation that doesn't understand
* DSA2 anyway. */
for (sk_rover = sk_list; sk_rover; sk_rover = sk_rover->next )
{
if (sk_rover->pk->pubkey_algo == PUBKEY_ALGO_DSA
|| sk_rover->pk->pubkey_algo == PUBKEY_ALGO_ECDSA)
{
int temp_hashlen = (gcry_mpi_get_nbits
(sk_rover->pk->pkey[1]));
if (sk_rover->pk->pubkey_algo == PUBKEY_ALGO_ECDSA)
{
temp_hashlen = ecdsa_qbits_from_Q (temp_hashlen);
if (!temp_hashlen)
conflict = 1; /* Better don't use the prefs. */
temp_hashlen = (temp_hashlen+7)/8;
/* Fixup for that funny nistp521 (yes, 521)
* were we need to use a 512 bit hash algo. */
if (temp_hashlen == 66)
temp_hashlen = 64;
}
else
if (sk_rover->pk->pubkey_algo == PUBKEY_ALGO_ECDSA)
{
temp_hashlen = ecdsa_qbits_from_Q (temp_hashlen);
if (!temp_hashlen)
conflict = 1; /* Better don't use the prefs. */
temp_hashlen = (temp_hashlen+7)/8;
/* Fixup for that funny nistp521 (yes, 521)
* were we need to use a 512 bit hash algo. */
if (temp_hashlen == 66)
temp_hashlen = 64;
}
else
temp_hashlen = (temp_hashlen+7)/8;
/* Pick a hash that is large enough for our
largest q or matches our Q but if tehreare
several of them we run into a conflict and
don't use the preferences. */
if (hint.digest_length < temp_hashlen)
{
if (sk_rover->pk->pubkey_algo == PUBKEY_ALGO_ECDSA)
{
if (hint.exact)
conflict = 1;
hint.exact = 1;
}
hint.digest_length = temp_hashlen;
}
}
}
if (!conflict
&& (algo = select_algo_from_prefs (pk_list,PREFTYPE_HASH,
-1,&hint)) > 0)
{
/* Note that we later check that the algo is not weak. */
recipient_digest_algo = algo;
/* Pick a hash that is large enough for our
* largest q or matches our Q but if tehreare
* several of them we run into a conflict and
* don't use the preferences. */
if (hint.digest_length < temp_hashlen)
{
if (sk_rover->pk->pubkey_algo == PUBKEY_ALGO_ECDSA)
{
if (hint.exact)
conflict = 1;
hint.exact = 1;
}
hint.digest_length = temp_hashlen;
}
}
}
}
}
for (sk_rover = sk_list; sk_rover; sk_rover = sk_rover->next)
gcry_md_enable (mfx.md, hash_for (sk_rover->pk));
if( !multifile )
iobuf_push_filter( inp, md_filter, &mfx );
if( detached && !encryptflag)
afx->what = 2;
if( opt.armor && !outfile )
push_armor_filter (afx, out);
if( encryptflag ) {
efx.pk_list = pk_list;
/* fixme: set efx.cfx.datalen if known */
iobuf_push_filter( out, encrypt_filter, &efx );
if (!conflict
&& (algo = select_algo_from_prefs (pk_list,PREFTYPE_HASH,
-1,&hint)) > 0)
{
/* Note that we later check that the algo is not weak. */
recipient_digest_algo = algo;
}
}
}
if (opt.compress_algo && !outfile && !detached)
{
int compr_algo=opt.compress_algo;
for (sk_rover = sk_list; sk_rover; sk_rover = sk_rover->next)
gcry_md_enable (mfx.md, hash_for (sk_rover->pk));
/* If not forced by user */
if(compr_algo==-1)
{
/* If we're not encrypting, then select_algo_from_prefs
will fail and we'll end up with the default. If we are
encrypting, select_algo_from_prefs cannot fail since
there is an assumed preference for uncompressed data.
Still, if it did fail, we'll also end up with the
default. */
if (!multifile)
iobuf_push_filter (inp, md_filter, &mfx);
if((compr_algo=
select_algo_from_prefs(pk_list,PREFTYPE_ZIP,-1,NULL))==-1)
compr_algo=default_compress_algo();
}
else if(!opt.expert && pk_list
&& select_algo_from_prefs(pk_list,PREFTYPE_ZIP,
compr_algo,NULL)!=compr_algo)
log_info(_("WARNING: forcing compression algorithm %s (%d)"
" violates recipient preferences\n"),
compress_algo_to_string(compr_algo),compr_algo);
if (detached && !encryptflag)
afx->what = 2;
/* algo 0 means no compression */
if( compr_algo )
push_compress_filter(out,&zfx,compr_algo);
}
if (opt.armor && !outfile)
push_armor_filter (afx, out);
/* Write the one-pass signature packets if needed */
if (!detached) {
rc = write_onepass_sig_packets (sk_list, out,
opt.textmode && !outfile ? 0x01:0x00);
if (rc)
goto leave;
if (encryptflag)
{
efx.pk_list = pk_list;
/* fixme: set efx.cfx.datalen if known */
iobuf_push_filter( out, encrypt_filter, &efx );
}
write_status_begin_signing (mfx.md);
if (opt.compress_algo && !outfile && !detached)
{
int compr_algo = opt.compress_algo;
/* Setup the inner packet. */
if( detached ) {
if( multifile ) {
strlist_t sl;
if (!opt.explicit_compress_option
&& is_file_compressed (peekbuf, peekbuflen))
{
if (opt.verbose)
log_info(_("'%s' already compressed\n"), fname? fname: "[stdin]");
compr_algo = 0;
}
else if (compr_algo==-1)
{
/* If we're not encrypting, then select_algo_from_prefs
* will fail and we'll end up with the default. If we are
* encrypting, select_algo_from_prefs cannot fail since
* there is an assumed preference for uncompressed data.
* Still, if it did fail, we'll also end up with the
* default. */
if ((compr_algo = select_algo_from_prefs (pk_list, PREFTYPE_ZIP,
-1, NULL)) == -1)
{
compr_algo = default_compress_algo();
}
}
else if (!opt.expert && pk_list
&& select_algo_from_prefs (pk_list, PREFTYPE_ZIP,
compr_algo, NULL) != compr_algo)
{
log_info (_("WARNING: forcing compression algorithm %s (%d)"
" violates recipient preferences\n"),
compress_algo_to_string (compr_algo), compr_algo);
}
if( opt.verbose )
log_info(_("signing:") );
/* must walk reverse trough this list */
for( sl = strlist_last(filenames); sl;
sl = strlist_prev( filenames, sl ) ) {
inp = iobuf_open(sl->d);
if (inp && is_secured_file (iobuf_get_fd (inp)))
{
iobuf_close (inp);
inp = NULL;
gpg_err_set_errno (EPERM);
}
if( !inp )
{
rc = gpg_error_from_syserror ();
log_error(_("can't open '%s': %s\n"),
sl->d,strerror(errno));
goto leave;
}
handle_progress (pfx, inp, sl->d);
if( opt.verbose )
log_printf (" '%s'", sl->d );
if(opt.textmode)
{
memset( &tfx, 0, sizeof tfx);
iobuf_push_filter( inp, text_filter, &tfx );
}
iobuf_push_filter( inp, md_filter, &mfx );
while (iobuf_read (inp, NULL, 1<<30) != -1 )
;
iobuf_close(inp); inp = NULL;
}
if( opt.verbose )
log_printf ("\n");
}
else {
/* read, so that the filter can calculate the digest */
while (iobuf_read (inp, NULL, 1<<30) != -1 )
;
}
}
else {
rc = write_plaintext_packet (out, inp, fname,
opt.textmode && !outfile ?
(opt.mimemode? 'm':'t'):'b');
/* Algo 0 means no compression. */
if (compr_algo)
push_compress_filter (out, &zfx, compr_algo);
}
/* catch errors from above */
if (rc)
goto leave;
/* write the signatures */
rc = write_signature_packets (ctrl, sk_list, out, mfx.md,
opt.textmode && !outfile? 0x01 : 0x00,
0, duration, detached ? 'D':'S', NULL);
if( rc )
/* Write the one-pass signature packets if needed */
if (!detached)
{
rc = write_onepass_sig_packets (sk_list, out,
opt.textmode && !outfile ? 0x01:0x00);
if (rc)
goto leave;
leave:
if( rc )
iobuf_cancel(out);
else {
iobuf_close(out);
if (encryptflag)
write_status( STATUS_END_ENCRYPTION );
}
iobuf_close(inp);
gcry_md_close ( mfx.md );
release_sk_list( sk_list );
release_pk_list( pk_list );
recipient_digest_algo=0;
release_progress_context (pfx);
release_armor_context (afx);
return rc;
}
write_status_begin_signing (mfx.md);
/* Setup the inner packet. */
if (detached)
{
if (multifile)
{
strlist_t sl;
if (opt.verbose)
log_info(_("signing:") );
/* Must walk reverse trough this list. */
for (sl = strlist_last (filenames); sl;
sl = strlist_prev (filenames, sl))
{
inp = iobuf_open(sl->d);
if (inp && is_secured_file (iobuf_get_fd (inp)))
{
iobuf_close (inp);
inp = NULL;
gpg_err_set_errno (EPERM);
}
if (!inp)
{
rc = gpg_error_from_syserror ();
log_error(_("can't open '%s': %s\n"),
sl->d,strerror(errno));
goto leave;
}
handle_progress (pfx, inp, sl->d);
if (opt.verbose)
log_printf (" '%s'", sl->d );
if (opt.textmode)
{
memset( &tfx, 0, sizeof tfx);
iobuf_push_filter( inp, text_filter, &tfx );
}
iobuf_push_filter( inp, md_filter, &mfx );
while (iobuf_read (inp, NULL, 1<<30) != -1 )
;
iobuf_close(inp); inp = NULL;
}
if (opt.verbose)
log_printf ("\n");
}
else
{
/* Read, so that the filter can calculate the digest. */
while (iobuf_read (inp, NULL, 1<<30) != -1 )
;
}
}
else
{
rc = write_plaintext_packet (out, inp, fname,
opt.textmode && !outfile ?
(opt.mimemode? 'm':'t'):'b');
}
/* Catch errors from above. */
if (rc)
goto leave;
/* Write the signatures. */
rc = write_signature_packets (ctrl, sk_list, out, mfx.md,
opt.textmode && !outfile? 0x01 : 0x00,
0, duration, detached ? 'D':'S', NULL);
if (rc)
goto leave;
leave:
if (rc)
iobuf_cancel (out);
else
{
iobuf_close(out);
if (encryptflag)
write_status( STATUS_END_ENCRYPTION );
}
iobuf_close(inp);
gcry_md_close ( mfx.md );
release_sk_list( sk_list );
release_pk_list( pk_list );
recipient_digest_algo=0;
release_progress_context (pfx);
release_armor_context (afx);
return rc;
}
/****************