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gnupg/g10/armor.c
David Shaw 898aa0ed02 * armor.c, g10.c, kbnode.c, misc.c, pkclist.c, sign.c, build-packet.c, 
getkey.c, keydb.c, openfile.c, plaintext.c, status.c, gpgv.c, keygen.c,
options.h, sig-check.c, tdbio.h, encode.c, hkp.c, mainproc.c,
parse-packet.c, signal.c, textfilter.c: Edit all preprocessor instructions
to remove whitespace before the '#'.  This is not required by C89, but
there are some compilers out there that don't like it.
2003-05-22 03:00:23 +00:00

1337 lines
34 KiB
C
Raw Blame History

/* armor.c - Armor flter
* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003
* 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 2 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, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <ctype.h>
#include "errors.h"
#include "iobuf.h"
#include "memory.h"
#include "util.h"
#include "filter.h"
#include "packet.h"
#include "options.h"
#include "main.h"
#include "status.h"
#include "i18n.h"
#ifdef HAVE_DOSISH_SYSTEM
#define LF "\r\n"
#else
#define LF "\n"
#endif
#define MAX_LINELEN 20000
#define CRCINIT 0xB704CE
#define CRCPOLY 0X864CFB
#define CRCUPDATE(a,c) do { \
a = ((a) << 8) ^ crc_table[((a)&0xff >> 16) ^ (c)]; \
a &= 0x00ffffff; \
} while(0)
static u32 crc_table[256];
static byte bintoasc[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz"
"0123456789+/";
static byte asctobin[256]; /* runtime initialized */
static int is_initialized;
typedef enum {
fhdrHASArmor = 0,
fhdrNOArmor,
fhdrINIT,
fhdrINITCont,
fhdrINITSkip,
fhdrCHECKBegin,
fhdrWAITHeader,
fhdrWAITClearsig,
fhdrSKIPHeader,
fhdrCLEARSIG,
fhdrREADClearsig,
fhdrNullClearsig,
fhdrEMPTYClearsig,
fhdrCHECKClearsig,
fhdrCHECKClearsig2,
fhdrCHECKDashEscaped,
fhdrCHECKDashEscaped2,
fhdrCHECKDashEscaped3,
fhdrREADClearsigNext,
fhdrENDClearsig,
fhdrENDClearsigHelp,
fhdrTESTSpaces,
fhdrCLEARSIGSimple,
fhdrCLEARSIGSimpleNext,
fhdrTEXT,
fhdrTEXTSimple,
fhdrERROR,
fhdrERRORShow,
fhdrEOF
} fhdr_state_t;
/* if we encounter this armor string with this index, go
* into a mode which fakes packets and wait for the next armor */
#define BEGIN_SIGNATURE 2
#define BEGIN_SIGNED_MSG_IDX 3
static char *head_strings[] = {
"BEGIN PGP MESSAGE",
"BEGIN PGP PUBLIC KEY BLOCK",
"BEGIN PGP SIGNATURE",
"BEGIN PGP SIGNED MESSAGE",
"BEGIN PGP ARMORED FILE", /* gnupg extension */
"BEGIN PGP PRIVATE KEY BLOCK",
"BEGIN PGP SECRET KEY BLOCK", /* only used by pgp2 */
NULL
};
static char *tail_strings[] = {
"END PGP MESSAGE",
"END PGP PUBLIC KEY BLOCK",
"END PGP SIGNATURE",
"END dummy",
"END PGP ARMORED FILE",
"END PGP PRIVATE KEY BLOCK",
"END PGP SECRET KEY BLOCK",
NULL
};
static void
initialize(void)
{
int i, j;
u32 t;
byte *s;
/* init the crc lookup table */
crc_table[0] = 0;
for(i=j=0; j < 128; j++ ) {
t = crc_table[j];
if( t & 0x00800000 ) {
t <<= 1;
crc_table[i++] = t ^ CRCPOLY;
crc_table[i++] = t;
}
else {
t <<= 1;
crc_table[i++] = t;
crc_table[i++] = t ^ CRCPOLY;
}
}
/* build the helptable for radix64 to bin conversion */
for(i=0; i < 256; i++ )
asctobin[i] = 255; /* used to detect invalid characters */
for(s=bintoasc,i=0; *s; s++,i++ )
asctobin[*s] = i;
is_initialized=1;
}
/****************
* Check whether this is an armored file or not See also
* parse-packet.c for details on this code For unknown historic
* reasons we use a string here but only the first byte will be used.
* Returns: True if it seems to be armored
*/
static int
is_armored( const byte *buf )
{
int ctb, pkttype;
ctb = *buf;
if( !(ctb & 0x80) )
return 1; /* invalid packet: assume it is armored */
pkttype = ctb & 0x40 ? (ctb & 0x3f) : ((ctb>>2)&0xf);
switch( pkttype ) {
case PKT_MARKER:
case PKT_SYMKEY_ENC:
case PKT_ONEPASS_SIG:
case PKT_PUBLIC_KEY:
case PKT_SECRET_KEY:
case PKT_PUBKEY_ENC:
case PKT_SIGNATURE:
case PKT_COMMENT:
case PKT_OLD_COMMENT:
case PKT_PLAINTEXT:
case PKT_COMPRESSED:
case PKT_ENCRYPTED:
return 0; /* seems to be a regular packet: not armored */
}
return 1;
}
/****************
* Try to check whether the iobuf is armored
* Returns true if this may be the case; the caller should use the
* filter to do further processing.
*/
int
use_armor_filter( IOBUF a )
{
byte buf[1];
int n;
/* fixme: there might be a problem with iobuf_peek */
n = iobuf_peek(a, buf, 1 );
if( n == -1 )
return 0; /* EOF, doesn't matter whether armored or not */
if( !n )
return 1; /* can't check it: try armored */
return is_armored(buf);
}
static void
invalid_armor(void)
{
write_status(STATUS_BADARMOR);
g10_exit(1); /* stop here */
}
/****************
* check whether the armor header is valid on a signed message.
* this is for security reasons: the header lines are not included in the
* hash and by using some creative formatting rules, Mallory could fake
* any text at the beginning of a document; assuming it is read with
* a simple viewer. We only allow the Hash Header.
*/
static int
parse_hash_header( const char *line )
{
const char *s, *s2;
unsigned found = 0;
if( strlen(line) < 6 || strlen(line) > 60 )
return 0; /* too short or too long */
if( memcmp( line, "Hash:", 5 ) )
return 0; /* invalid header */
s = line+5;
for(s=line+5;;s=s2) {
for(; *s && (*s==' ' || *s == '\t'); s++ )
;
if( !*s )
break;
for(s2=s+1; *s2 && *s2!=' ' && *s2 != '\t' && *s2 != ','; s2++ )
;
if( !strncmp( s, "RIPEMD160", s2-s ) )
found |= 1;
else if( !strncmp( s, "SHA1", s2-s ) )
found |= 2;
else if( !strncmp( s, "MD5", s2-s ) )
found |= 4;
else if( !strncmp( s, "TIGER192", s2-s ) )
found |= 8;
else if( !strncmp( s, "TIGER", s2-s ) ) /* used by old versions */
found |= 8;
else if( !strncmp( s, "SHA256", s2-s ) )
found |= 16;
else if( !strncmp( s, "SHA384", s2-s ) )
found |= 32;
else if( !strncmp( s, "SHA512", s2-s ) )
found |= 64;
else
return 0;
for(; *s2 && (*s2==' ' || *s2 == '\t'); s2++ )
;
if( *s2 && *s2 != ',' )
return 0;
if( *s2 )
s2++;
}
return found;
}
/****************
* Check whether this is a armor line.
* returns: -1 if it is not a armor header or the index number of the
* armor header.
*/
static int
is_armor_header( byte *line, unsigned len )
{
const char *s;
byte *save_p, *p;
int save_c;
int i;
if( len < 15 )
return -1; /* too short */
if( memcmp( line, "-----", 5 ) )
return -1; /* no */
p = strstr( line+5, "-----");
if( !p )
return -1;
save_p = p;
p += 5;
/* Some mail programs on Windows seem to add spaces to the end of
the line. This becomes strict if --openpgp is set. */
if(!RFC2440)
while(*p==' ')
p++;
if( *p == '\r' )
p++;
if( *p == '\n' )
p++;
if( *p )
return -1; /* garbage after dashes */
save_c = *save_p; *save_p = 0;
p = line+5;
for(i=0; (s=head_strings[i]); i++ )
if( !strcmp(s, p) )
break;
*save_p = save_c;
if( !s )
return -1; /* unknown armor line */
if( opt.verbose > 1 )
log_info(_("armor: %s\n"), head_strings[i]);
return i;
}
/****************
* Parse a header lines
* Return 0: Empty line (end of header lines)
* -1: invalid header line
* >0: Good header line
*/
static int
parse_header_line( armor_filter_context_t *afx, byte *line, unsigned int len )
{
byte *p;
int hashes=0;
unsigned int len2;
len2 = check_trailing_ws( line, len );
if( !len2 ) {
afx->buffer_pos = len2; /* (it is not the fine way to do it here) */
return 0; /* WS only: same as empty line */
}
len = len2;
line[len2] = 0;
p = strchr( line, ':');
if( !p || !p[1] ) {
log_error(_("invalid armor header: "));
print_string( stderr, line, len, 0 );
putc('\n', stderr);
return -1;
}
if( opt.verbose ) {
log_info(_("armor header: "));
print_string( stderr, line, len, 0 );
putc('\n', stderr);
}
if( afx->in_cleartext ) {
if( (hashes=parse_hash_header( line )) )
afx->hashes |= hashes;
else if( strlen(line) > 15 && !memcmp( line, "NotDashEscaped:", 15 ) )
afx->not_dash_escaped = 1;
else {
log_error(_("invalid clearsig header\n"));
return -1;
}
}
return 1;
}
/* figure out whether the data is armored or not */
static int
check_input( armor_filter_context_t *afx, IOBUF a )
{
int rc = 0;
int i;
byte *line;
unsigned len;
unsigned maxlen;
int hdr_line = -1;
/* read the first line to see whether this is armored data */
maxlen = MAX_LINELEN;
len = afx->buffer_len = iobuf_read_line( a, &afx->buffer,
&afx->buffer_size, &maxlen );
line = afx->buffer;
if( !maxlen ) {
/* line has been truncated: assume not armored */
afx->inp_checked = 1;
afx->inp_bypass = 1;
return 0;
}
if( !len ) {
return -1; /* eof */
}
/* (the line is always a C string but maybe longer) */
if( *line == '\n' || ( len && (*line == '\r' && line[1]=='\n') ) )
;
else if( !is_armored( line ) ) {
afx->inp_checked = 1;
afx->inp_bypass = 1;
return 0;
}
/* find the armor header */
while(len) {
i = is_armor_header( line, len );
if( i >= 0 && !(afx->only_keyblocks && i != 1 && i != 5 && i != 6 )) {
hdr_line = i;
if( hdr_line == BEGIN_SIGNED_MSG_IDX ) {
if( afx->in_cleartext ) {
log_error(_("nested clear text signatures\n"));
rc = G10ERR_INVALID_ARMOR;
}
afx->in_cleartext = 1;
}
break;
}
/* read the next line (skip all truncated lines) */
do {
maxlen = MAX_LINELEN;
afx->buffer_len = iobuf_read_line( a, &afx->buffer,
&afx->buffer_size, &maxlen );
line = afx->buffer;
len = afx->buffer_len;
} while( !maxlen );
}
/* parse the header lines */
while(len) {
/* read the next line (skip all truncated lines) */
do {
maxlen = MAX_LINELEN;
afx->buffer_len = iobuf_read_line( a, &afx->buffer,
&afx->buffer_size, &maxlen );
line = afx->buffer;
len = afx->buffer_len;
} while( !maxlen );
i = parse_header_line( afx, line, len );
if( i <= 0 ) {
if( i )
rc = G10ERR_INVALID_ARMOR;
break;
}
}
if( rc )
invalid_armor();
else if( afx->in_cleartext )
afx->faked = 1;
else {
afx->inp_checked = 1;
afx->crc = CRCINIT;
afx->idx = 0;
afx->radbuf[0] = 0;
}
return rc;
}
/****************
* Fake a literal data packet and wait for the next armor line
* fixme: empty line handling and null length clear text signature are
* not implemented/checked.
*/
static int
fake_packet( armor_filter_context_t *afx, IOBUF a,
size_t *retn, byte *buf, size_t size )
{
int rc = 0;
size_t len = 0;
int lastline = 0;
unsigned maxlen, n;
byte *p;
len = 2; /* reserve 2 bytes for the length header */
size -= 2; /* and 2 for the terminating header */
while( !rc && len < size ) {
/* copy what we have in the line buffer */
if( afx->faked == 1 )
afx->faked++; /* skip the first (empty) line */
else {
while( len < size && afx->buffer_pos < afx->buffer_len )
buf[len++] = afx->buffer[afx->buffer_pos++];
if( len >= size )
continue;
}
/* read the next line */
maxlen = MAX_LINELEN;
afx->buffer_pos = 0;
afx->buffer_len = iobuf_read_line( a, &afx->buffer,
&afx->buffer_size, &maxlen );
if( !afx->buffer_len ) {
rc = -1; /* eof (should not happen) */
continue;
}
if( !maxlen )
afx->truncated++;
if( !afx->not_dash_escaped ) {
int crlf;
p = afx->buffer;
n = afx->buffer_len;
crlf = n > 1 && p[n-2] == '\r' && p[n-1]=='\n';
/* PGP2 does not treat a tab as white space character */
afx->buffer_len = trim_trailing_chars( p, n,
afx->pgp2mode ? " \r\n" : " \t\r\n");
/* the buffer is always allocated with enough space to append
* the removed [CR], LF and a Nul
* The reason for this complicated procedure is to keep at least
* the original type of lineending - handling of the removed
* trailing spaces seems to be impossible in our method
* of faking a packet; either we have to use a temporary file
* or calculate the hash here in this module and somehow find
* a way to send the hash down the processing line (well, a special
* faked packet could do the job).
*/
if( crlf )
afx->buffer[afx->buffer_len++] = '\r';
afx->buffer[afx->buffer_len++] = '\n';
afx->buffer[afx->buffer_len] = 0;
}
p = afx->buffer;
n = afx->buffer_len;
if( n > 2 && *p == '-' ) {
/* check for dash escaped or armor header */
if( p[1] == ' ' && !afx->not_dash_escaped ) {
/* issue a warning if it is not regular encoded */
if( p[2] != '-' && !( n > 6 && !memcmp(p+2, "From ", 5))) {
log_info(_("invalid dash escaped line: "));
print_string( stderr, p, n, 0 );
putc('\n', stderr);
}
afx->buffer_pos = 2; /* skip */
}
else if( n >= 15 && p[1] == '-' && p[2] == '-' && p[3] == '-' ) {
int type = is_armor_header( p, n );
if( afx->not_dash_escaped && type != BEGIN_SIGNATURE )
; /* this is okay */
else {
if( type != BEGIN_SIGNATURE ) {
log_info(_("unexpected armor:"));
print_string( stderr, p, n, 0 );
putc('\n', stderr);
}
lastline = 1;
rc = -1;
}
}
}
}
buf[0] = (len-2) >> 8;
buf[1] = (len-2);
if( lastline ) { /* write last (ending) length header */
if( buf[0] || buf[1] ) { /* only if we have some text */
buf[len++] = 0;
buf[len++] = 0;
}
rc = 0;
afx->faked = 0;
afx->in_cleartext = 0;
/* and now read the header lines */
afx->buffer_pos = 0;
for(;;) {
int i;
/* read the next line (skip all truncated lines) */
do {
maxlen = MAX_LINELEN;
afx->buffer_len = iobuf_read_line( a, &afx->buffer,
&afx->buffer_size, &maxlen );
} while( !maxlen );
p = afx->buffer;
n = afx->buffer_len;
if( !n ) {
rc = -1;
break; /* eof */
}
i = parse_header_line( afx, p , n );
if( i <= 0 ) {
if( i )
invalid_armor();
break;
}
}
afx->inp_checked = 1;
afx->crc = CRCINIT;
afx->idx = 0;
afx->radbuf[0] = 0;
}
*retn = len;
return rc;
}
static int
invalid_crc(void)
{
if ( opt.ignore_crc_error )
return 0;
log_inc_errorcount();
return G10ERR_INVALID_ARMOR;
}
static int
radix64_read( armor_filter_context_t *afx, IOBUF a, size_t *retn,
byte *buf, size_t size )
{
byte val;
int c=0, c2; /*init c because gcc is not clever enough for the continue*/
int checkcrc=0;
int rc = 0;
size_t n = 0;
int idx, i;
u32 crc;
crc = afx->crc;
idx = afx->idx;
val = afx->radbuf[0];
for( n=0; n < size; ) {
if( afx->buffer_pos < afx->buffer_len )
c = afx->buffer[afx->buffer_pos++];
else { /* read the next line */
unsigned maxlen = MAX_LINELEN;
afx->buffer_pos = 0;
afx->buffer_len = iobuf_read_line( a, &afx->buffer,
&afx->buffer_size, &maxlen );
if( !maxlen )
afx->truncated++;
if( !afx->buffer_len )
break; /* eof */
continue;
}
again:
if( c == '\n' || c == ' ' || c == '\r' || c == '\t' )
continue;
else if( c == '=' ) { /* pad character: stop */
/* some mailers leave quoted-printable encoded characters
* so we try to workaround this */
if( afx->buffer_pos+2 < afx->buffer_len ) {
int cc1, cc2, cc3;
cc1 = afx->buffer[afx->buffer_pos];
cc2 = afx->buffer[afx->buffer_pos+1];
cc3 = afx->buffer[afx->buffer_pos+2];
if( isxdigit(cc1) && isxdigit(cc2)
&& strchr( "=\n\r\t ", cc3 )) {
/* well it seems to be the case - adjust */
c = isdigit(cc1)? (cc1 - '0'): (ascii_toupper(cc1)-'A'+10);
c <<= 4;
c |= isdigit(cc2)? (cc2 - '0'): (ascii_toupper(cc2)-'A'+10);
afx->buffer_pos += 2;
afx->qp_detected = 1;
goto again;
}
}
if( idx == 1 )
buf[n++] = val;
checkcrc++;
break;
}
else if( (c = asctobin[(c2=c)]) == 255 ) {
log_error(_("invalid radix64 character %02x skipped\n"), c2);
continue;
}
switch(idx) {
case 0: val = c << 2; break;
case 1: val |= (c>>4)&3; buf[n++]=val;val=(c<<4)&0xf0;break;
case 2: val |= (c>>2)&15; buf[n++]=val;val=(c<<6)&0xc0;break;
case 3: val |= c&0x3f; buf[n++] = val; break;
}
idx = (idx+1) % 4;
}
for(i=0; i < n; i++ )
crc = (crc << 8) ^ crc_table[((crc >> 16)&0xff) ^ buf[i]];
crc &= 0x00ffffff;
afx->crc = crc;
afx->idx = idx;
afx->radbuf[0] = val;
if( checkcrc ) {
afx->any_data = 1;
afx->inp_checked=0;
afx->faked = 0;
for(;;) { /* skip lf and pad characters */
if( afx->buffer_pos < afx->buffer_len )
c = afx->buffer[afx->buffer_pos++];
else { /* read the next line */
unsigned maxlen = MAX_LINELEN;
afx->buffer_pos = 0;
afx->buffer_len = iobuf_read_line( a, &afx->buffer,
&afx->buffer_size, &maxlen );
if( !maxlen )
afx->truncated++;
if( !afx->buffer_len )
break; /* eof */
continue;
}
if( c == '\n' || c == ' ' || c == '\r'
|| c == '\t' || c == '=' )
continue;
break;
}
if( c == -1 )
log_error(_("premature eof (no CRC)\n"));
else {
u32 mycrc = 0;
idx = 0;
do {
if( (c = asctobin[c]) == 255 )
break;
switch(idx) {
case 0: val = c << 2; break;
case 1: val |= (c>>4)&3; mycrc |= val << 16;val=(c<<4)&0xf0;break;
case 2: val |= (c>>2)&15; mycrc |= val << 8;val=(c<<6)&0xc0;break;
case 3: val |= c&0x3f; mycrc |= val; break;
}
for(;;) {
if( afx->buffer_pos < afx->buffer_len )
c = afx->buffer[afx->buffer_pos++];
else { /* read the next line */
unsigned maxlen = MAX_LINELEN;
afx->buffer_pos = 0;
afx->buffer_len = iobuf_read_line( a, &afx->buffer,
&afx->buffer_size,
&maxlen );
if( !maxlen )
afx->truncated++;
if( !afx->buffer_len )
break; /* eof */
continue;
}
break;
}
if( !afx->buffer_len )
break; /* eof */
} while( ++idx < 4 );
if( c == -1 ) {
log_info(_("premature eof (in CRC)\n"));
rc = invalid_crc();
}
else if( idx != 4 ) {
log_info(_("malformed CRC\n"));
rc = invalid_crc();
}
else if( mycrc != afx->crc ) {
log_info (_("CRC error; %06lx - %06lx\n"),
(ulong)afx->crc, (ulong)mycrc);
rc = invalid_crc();
}
else {
rc = 0;
/* FIXME: Here we should emit another control packet,
* so that we know in mainproc that we are processing
* a clearsign message */
#if 0
for(rc=0;!rc;) {
rc = 0 /*check_trailer( &fhdr, c )*/;
if( !rc ) {
if( (c=iobuf_get(a)) == -1 )
rc = 2;
}
}
if( rc == -1 )
rc = 0;
else if( rc == 2 ) {
log_error(_("premature eof (in Trailer)\n"));
rc = G10ERR_INVALID_ARMOR;
}
else {
log_error(_("error in trailer line\n"));
rc = G10ERR_INVALID_ARMOR;
}
#endif
}
}
}
if( !n )
rc = -1;
*retn = n;
return rc;
}
/****************
* This filter is used to handle the armor stuff
*/
int
armor_filter( void *opaque, int control,
IOBUF a, byte *buf, size_t *ret_len)
{
size_t size = *ret_len;
armor_filter_context_t *afx = opaque;
int rc=0, i, c;
byte radbuf[3];
int idx, idx2;
size_t n=0;
u32 crc;
#if 0
static FILE *fp ;
if( !fp ) {
fp = fopen("armor.out", "w");
assert(fp);
}
#endif
if( DBG_FILTER )
log_debug("armor-filter: control: %d\n", control );
if( control == IOBUFCTRL_UNDERFLOW && afx->inp_bypass ) {
n = 0;
if( afx->buffer_len ) {
for(; n < size && afx->buffer_pos < afx->buffer_len; n++ )
buf[n++] = afx->buffer[afx->buffer_pos++];
if( afx->buffer_pos >= afx->buffer_len )
afx->buffer_len = 0;
}
for(; n < size; n++ ) {
if( (c=iobuf_get(a)) == -1 )
break;
buf[n] = c & 0xff;
}
if( !n )
rc = -1;
*ret_len = n;
}
else if( control == IOBUFCTRL_UNDERFLOW ) {
/* We need some space for the faked packet. The minmum required
* size is ~18 + length of the session marker */
if( size < 50 )
BUG(); /* supplied buffer too short */
if( afx->faked )
rc = fake_packet( afx, a, &n, buf, size );
else if( !afx->inp_checked ) {
rc = check_input( afx, a );
if( afx->inp_bypass ) {
for(n=0; n < size && afx->buffer_pos < afx->buffer_len; )
buf[n++] = afx->buffer[afx->buffer_pos++];
if( afx->buffer_pos >= afx->buffer_len )
afx->buffer_len = 0;
if( !n )
rc = -1;
}
else if( afx->faked ) {
unsigned int hashes = afx->hashes;
const byte *sesmark;
size_t sesmarklen;
sesmark = get_session_marker( &sesmarklen );
if ( sesmarklen > 20 )
BUG();
/* the buffer is at least 15+n*15 bytes long, so it
* is easy to construct the packets */
hashes &= 1|2|4|8|16|32|64;
if( !hashes ) {
hashes |= 4; /* default to MD 5 */
/* This is non-ideal since PGP 5-8 have the same
end-of-line bugs as PGP 2. However, we only
enable pgp2mode if there is no Hash: header. */
if( opt.pgp2_workarounds )
afx->pgp2mode = 1;
}
n=0;
/* first a gpg control packet */
buf[n++] = 0xff; /* new format, type 63, 1 length byte */
n++; /* see below */
memcpy(buf+n, sesmark, sesmarklen ); n+= sesmarklen;
buf[n++] = CTRLPKT_CLEARSIGN_START;
buf[n++] = afx->not_dash_escaped? 0:1; /* sigclass */
if( hashes & 1 )
buf[n++] = DIGEST_ALGO_RMD160;
if( hashes & 2 )
buf[n++] = DIGEST_ALGO_SHA1;
if( hashes & 4 )
buf[n++] = DIGEST_ALGO_MD5;
if( hashes & 8 )
buf[n++] = DIGEST_ALGO_TIGER;
if( hashes & 16 )
buf[n++] = DIGEST_ALGO_SHA256;
if( hashes & 32 )
buf[n++] = DIGEST_ALGO_SHA384;
if( hashes & 64 )
buf[n++] = DIGEST_ALGO_SHA512;
buf[1] = n - 2;
/* followed by a plaintext packet */
buf[n++] = 0xaf; /* old packet format, type 11, var length */
buf[n++] = 0; /* set the length header */
buf[n++] = 6;
buf[n++] = 't'; /* canonical text mode */
buf[n++] = 0; /* namelength */
memset(buf+n, 0, 4); /* timestamp */
n += 4;
}
else if( !rc )
rc = radix64_read( afx, a, &n, buf, size );
}
else
rc = radix64_read( afx, a, &n, buf, size );
#if 0
if( n )
if( fwrite(buf, n, 1, fp ) != 1 )
BUG();
#endif
*ret_len = n;
}
else if( control == IOBUFCTRL_FLUSH && !afx->cancel ) {
if( !afx->status ) { /* write the header line */
const char *s;
if( afx->what >= DIM(head_strings) )
log_bug("afx->what=%d", afx->what);
iobuf_writestr(a, "-----");
iobuf_writestr(a, head_strings[afx->what] );
iobuf_writestr(a, "-----" LF );
if( !opt.no_version )
iobuf_writestr(a, "Version: GnuPG v" VERSION " ("
PRINTABLE_OS_NAME ")" LF );
/* write the comment string or a default one */
s = opt.comment_string;
if( s && *s ) {
iobuf_writestr(a, "Comment: " );
for( ; *s; s++ ) {
if( *s == '\n' )
iobuf_writestr(a, "\\n" );
else if( *s == '\r' )
iobuf_writestr(a, "\\r" );
else if( *s == '\v' )
iobuf_writestr(a, "\\v" );
else
iobuf_put(a, *s );
}
iobuf_writestr(a, LF );
}
if ( afx->hdrlines ) {
for ( s = afx->hdrlines; *s; s++ ) {
#ifdef HAVE_DOSISH_SYSTEM
if ( *s == '\n' )
iobuf_put( a, '\r');
#endif
iobuf_put(a, *s );
}
}
iobuf_writestr(a, LF );
afx->status++;
afx->idx = 0;
afx->idx2 = 0;
afx->crc = CRCINIT;
}
crc = afx->crc;
idx = afx->idx;
idx2 = afx->idx2;
for(i=0; i < idx; i++ )
radbuf[i] = afx->radbuf[i];
for(i=0; i < size; i++ )
crc = (crc << 8) ^ crc_table[((crc >> 16)&0xff) ^ buf[i]];
crc &= 0x00ffffff;
for( ; size; buf++, size-- ) {
radbuf[idx++] = *buf;
if( idx > 2 ) {
idx = 0;
c = bintoasc[(*radbuf >> 2) & 077];
iobuf_put(a, c);
c = bintoasc[(((*radbuf<<4)&060)|((radbuf[1] >> 4)&017))&077];
iobuf_put(a, c);
c = bintoasc[(((radbuf[1]<<2)&074)|((radbuf[2]>>6)&03))&077];
iobuf_put(a, c);
c = bintoasc[radbuf[2]&077];
iobuf_put(a, c);
if( ++idx2 >= (64/4) ) { /* pgp doesn't like 72 here */
iobuf_writestr(a, LF );
idx2=0;
}
}
}
for(i=0; i < idx; i++ )
afx->radbuf[i] = radbuf[i];
afx->idx = idx;
afx->idx2 = idx2;
afx->crc = crc;
}
else if( control == IOBUFCTRL_INIT ) {
if( !is_initialized )
initialize();
}
else if( control == IOBUFCTRL_CANCEL ) {
afx->cancel = 1;
}
else if( control == IOBUFCTRL_FREE ) {
if( afx->cancel )
;
else if( afx->status ) { /* pad, write cecksum, and bottom line */
crc = afx->crc;
idx = afx->idx;
idx2 = afx->idx2;
for(i=0; i < idx; i++ )
radbuf[i] = afx->radbuf[i];
if( idx ) {
c = bintoasc[(*radbuf>>2)&077];
iobuf_put(a, c);
if( idx == 1 ) {
c = bintoasc[((*radbuf << 4) & 060) & 077];
iobuf_put(a, c);
iobuf_put(a, '=');
iobuf_put(a, '=');
}
else { /* 2 */
c = bintoasc[(((*radbuf<<4)&060)|((radbuf[1]>>4)&017))&077];
iobuf_put(a, c);
c = bintoasc[((radbuf[1] << 2) & 074) & 077];
iobuf_put(a, c);
iobuf_put(a, '=');
}
if( ++idx2 >= (64/4) ) { /* pgp doesn't like 72 here */
iobuf_writestr(a, LF );
idx2=0;
}
}
/* may need a linefeed */
if( idx2 )
iobuf_writestr(a, LF );
/* write the CRC */
iobuf_put(a, '=');
radbuf[0] = crc >>16;
radbuf[1] = crc >> 8;
radbuf[2] = crc;
c = bintoasc[(*radbuf >> 2) & 077];
iobuf_put(a, c);
c = bintoasc[(((*radbuf<<4)&060)|((radbuf[1] >> 4)&017))&077];
iobuf_put(a, c);
c = bintoasc[(((radbuf[1]<<2)&074)|((radbuf[2]>>6)&03))&077];
iobuf_put(a, c);
c = bintoasc[radbuf[2]&077];
iobuf_put(a, c);
iobuf_writestr(a, LF );
/* and the the trailer */
if( afx->what >= DIM(tail_strings) )
log_bug("afx->what=%d", afx->what);
iobuf_writestr(a, "-----");
iobuf_writestr(a, tail_strings[afx->what] );
iobuf_writestr(a, "-----" LF );
}
else if( !afx->any_data && !afx->inp_bypass ) {
log_error(_("no valid OpenPGP data found.\n"));
afx->no_openpgp_data = 1;
write_status_text( STATUS_NODATA, "1" );
}
if( afx->truncated )
log_info(_("invalid armor: line longer than %d characters\n"),
MAX_LINELEN );
/* issue an error to enforce dissemination of correct software */
if( afx->qp_detected )
log_error(_("quoted printable character in armor - "
"probably a buggy MTA has been used\n") );
m_free( afx->buffer );
afx->buffer = NULL;
}
else if( control == IOBUFCTRL_DESC )
*(char**)buf = "armor_filter";
return rc;
}
/****************
* create a radix64 encoded string.
*/
char *
make_radix64_string( const byte *data, size_t len )
{
char *buffer, *p;
buffer = p = m_alloc( (len+2)/3*4 + 1 );
for( ; len >= 3 ; len -= 3, data += 3 ) {
*p++ = bintoasc[(data[0] >> 2) & 077];
*p++ = bintoasc[(((data[0] <<4)&060)|((data[1] >> 4)&017))&077];
*p++ = bintoasc[(((data[1]<<2)&074)|((data[2]>>6)&03))&077];
*p++ = bintoasc[data[2]&077];
}
if( len == 2 ) {
*p++ = bintoasc[(data[0] >> 2) & 077];
*p++ = bintoasc[(((data[0] <<4)&060)|((data[1] >> 4)&017))&077];
*p++ = bintoasc[((data[1]<<2)&074)];
}
else if( len == 1 ) {
*p++ = bintoasc[(data[0] >> 2) & 077];
*p++ = bintoasc[(data[0] <<4)&060];
}
*p = 0;
return buffer;
}
/***********************************************
* For the pipemode command we can't use the armor filter for various
* reasons, so we use this new unarmor_pump stuff to remove the armor
*/
enum unarmor_state_e {
STA_init = 0,
STA_bypass,
STA_wait_newline,
STA_wait_dash,
STA_first_dash,
STA_compare_header,
STA_found_header_wait_newline,
STA_skip_header_lines,
STA_skip_header_lines_non_ws,
STA_read_data,
STA_wait_crc,
STA_read_crc,
STA_ready
};
struct unarmor_pump_s {
enum unarmor_state_e state;
byte val;
int checkcrc;
int pos; /* counts from 0..3 */
u32 crc;
u32 mycrc; /* the one store in the data */
};
UnarmorPump
unarmor_pump_new (void)
{
UnarmorPump x;
if( !is_initialized )
initialize();
x = m_alloc_clear (sizeof *x);
return x;
}
void
unarmor_pump_release (UnarmorPump x)
{
m_free (x);
}
/*
* Get the next character from the ascii armor taken from the IOBUF
* created earlier by unarmor_pump_new().
* Return: c = Character
* 256 = ignore this value
* -1 = End of current armor
* -2 = Premature EOF (not used)
* -3 = Invalid armor
*/
int
unarmor_pump (UnarmorPump x, int c)
{
int rval = 256; /* default is to ignore the return value */
switch (x->state) {
case STA_init:
{
byte tmp[1];
tmp[0] = c;
if ( is_armored (tmp) )
x->state = c == '-'? STA_first_dash : STA_wait_newline;
else {
x->state = STA_bypass;
return c;
}
}
break;
case STA_bypass:
return c; /* return here to avoid crc calculation */
case STA_wait_newline:
if (c == '\n')
x->state = STA_wait_dash;
break;
case STA_wait_dash:
x->state = c == '-'? STA_first_dash : STA_wait_newline;
break;
case STA_first_dash: /* just need for initalization */
x->pos = 0;
x->state = STA_compare_header;
case STA_compare_header:
if ( "-----BEGIN PGP SIGNATURE-----"[++x->pos] == c ) {
if ( x->pos == 28 )
x->state = STA_found_header_wait_newline;
}
else
x->state = c == '\n'? STA_wait_dash : STA_wait_newline;
break;
case STA_found_header_wait_newline:
/* to make CR,LF issues easier we simply allow for white space
behind the 5 dashes */
if ( c == '\n' )
x->state = STA_skip_header_lines;
else if ( c != '\r' && c != ' ' && c != '\t' )
x->state = STA_wait_dash; /* garbage after the header line */
break;
case STA_skip_header_lines:
/* i.e. wait for one empty line */
if ( c == '\n' ) {
x->state = STA_read_data;
x->crc = CRCINIT;
x->val = 0;
x->pos = 0;
}
else if ( c != '\r' && c != ' ' && c != '\t' )
x->state = STA_skip_header_lines_non_ws;
break;
case STA_skip_header_lines_non_ws:
/* like above but we already encountered non white space */
if ( c == '\n' )
x->state = STA_skip_header_lines;
break;
case STA_read_data:
/* fixme: we don't check for the trailing dash lines but rely
* on the armor stop characters */
if( c == '\n' || c == ' ' || c == '\r' || c == '\t' )
break; /* skip all kind of white space */
if( c == '=' ) { /* pad character: stop */
if( x->pos == 1 ) /* in this case val has some value */
rval = x->val;
x->state = STA_wait_crc;
break;
}
{
int c2;
if( (c = asctobin[(c2=c)]) == 255 ) {
log_error(_("invalid radix64 character %02x skipped\n"), c2);
break;
}
}
switch(x->pos) {
case 0:
x->val = c << 2;
break;
case 1:
x->val |= (c>>4)&3;
rval = x->val;
x->val = (c<<4)&0xf0;
break;
case 2:
x->val |= (c>>2)&15;
rval = x->val;
x->val = (c<<6)&0xc0;
break;
case 3:
x->val |= c&0x3f;
rval = x->val;
break;
}
x->pos = (x->pos+1) % 4;
break;
case STA_wait_crc:
if( c == '\n' || c == ' ' || c == '\r' || c == '\t' || c == '=' )
break; /* skip ws and pad characters */
/* assume that we are at the next line */
x->state = STA_read_crc;
x->pos = 0;
x->mycrc = 0;
case STA_read_crc:
if( (c = asctobin[c]) == 255 ) {
rval = -1; /* ready */
if( x->crc != x->mycrc ) {
log_info (_("CRC error; %06lx - %06lx\n"),
(ulong)x->crc, (ulong)x->mycrc);
if ( invalid_crc() )
rval = -3;
}
x->state = STA_ready; /* not sure whether this is correct */
break;
}
switch(x->pos) {
case 0:
x->val = c << 2;
break;
case 1:
x->val |= (c>>4)&3;
x->mycrc |= x->val << 16;
x->val = (c<<4)&0xf0;
break;
case 2:
x->val |= (c>>2)&15;
x->mycrc |= x->val << 8;
x->val = (c<<6)&0xc0;
break;
case 3:
x->val |= c&0x3f;
x->mycrc |= x->val;
break;
}
x->pos = (x->pos+1) % 4;
break;
case STA_ready:
rval = -1;
break;
}
if ( !(rval & ~255) ) { /* compute the CRC */
x->crc = (x->crc << 8) ^ crc_table[((x->crc >> 16)&0xff) ^ rval];
x->crc &= 0x00ffffff;
}
return rval;
}
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