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gnupg/g10/misc.c
David Shaw c09b34fede * misc.c (print_digest_algo_note): The latest 2440bis drafts deprecates 
MD5, so give a warning. (print_pubkey_algo_note, print_cipher_algo_note,
print_digest_algo_note): Give the algorithm name in the experimental algo
warning.
2004-11-03 20:35:28 +00:00

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/* misc.c - miscellaneous functions
* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003,
* 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 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 <unistd.h>
#include <errno.h>
#if defined(__linux__) && defined(__alpha__) && __GLIBC__ < 2
#include <asm/sysinfo.h>
#include <asm/unistd.h>
#endif
#ifdef HAVE_SETRLIMIT
#include <time.h>
#include <sys/time.h>
#include <sys/resource.h>
#endif
#ifdef ENABLE_SELINUX_HACKS
#include <sys/stat.h>
#endif
#ifdef _WIN32
#include <time.h>
#include <process.h>
#endif
#include "util.h"
#include "main.h"
#include "photoid.h"
#include "options.h"
#include "i18n.h"
#include "cardglue.h"
#ifdef ENABLE_SELINUX_HACKS
/* A object and a global variable to keep track of files marked as
secured. */
struct secured_file_item
{
struct secured_file_item *next;
ino_t ino;
dev_t dev;
};
static struct secured_file_item *secured_files;
#endif /*ENABLE_SELINUX_HACKS*/
#if defined(__linux__) && defined(__alpha__) && __GLIBC__ < 2
static int
setsysinfo(unsigned long op, void *buffer, unsigned long size,
int *start, void *arg, unsigned long flag)
{
return syscall(__NR_osf_setsysinfo, op, buffer, size, start, arg, flag);
}
void
trap_unaligned(void)
{
unsigned int buf[2];
buf[0] = SSIN_UACPROC;
buf[1] = UAC_SIGBUS | UAC_NOPRINT;
setsysinfo(SSI_NVPAIRS, buf, 1, 0, 0, 0);
}
#else
void
trap_unaligned(void)
{ /* dummy */
}
#endif
int
disable_core_dumps()
{
#ifdef HAVE_DOSISH_SYSTEM
return 0;
#else
#ifdef HAVE_SETRLIMIT
struct rlimit limit;
limit.rlim_cur = 0;
limit.rlim_max = 0;
if( !setrlimit( RLIMIT_CORE, &limit ) )
return 0;
if( errno != EINVAL && errno != ENOSYS )
log_fatal(_("can't disable core dumps: %s\n"), strerror(errno) );
#endif
return 1;
#endif
}
/* For the sake of SELinux we want to restrict access through gpg to
certain files we keep under our own control. This function
registers such a file and is_secured_file may then be used to
check whether a file has ben registered as secured. */
void
register_secured_file (const char *fname)
{
#ifdef ENABLE_SELINUX_HACKS
struct stat buf;
struct secured_file_item *sf;
/* Note that we stop immediatley if something goes wrong here. */
if (stat (fname, &buf))
log_fatal (_("fstat of `%s' failed in %s: %s\n"), fname,
"register_secured_file", strerror (errno));
/* log_debug ("registering `%s' i=%lu.%lu\n", fname, */
/* (unsigned long)buf.st_dev, (unsigned long)buf.st_ino); */
for (sf=secured_files; sf; sf = sf->next)
{
if (sf->ino == buf.st_ino && sf->dev == buf.st_dev)
return; /* Already registered. */
}
sf = xmalloc (sizeof *sf);
sf->ino = buf.st_ino;
sf->dev = buf.st_dev;
sf->next = secured_files;
secured_files = sf;
#endif /*ENABLE_SELINUX_HACKS*/
}
/* Remove a file registerd as secure. */
void
unregister_secured_file (const char *fname)
{
#ifdef ENABLE_SELINUX_HACKS
struct stat buf;
struct secured_file_item *sf, *sfprev;
if (stat (fname, &buf))
{
log_error (_("fstat of `%s' failed in %s: %s\n"), fname,
"unregister_secured_file", strerror (errno));
return;
}
/* log_debug ("unregistering `%s' i=%lu.%lu\n", fname, */
/* (unsigned long)buf.st_dev, (unsigned long)buf.st_ino); */
for (sfprev=NULL,sf=secured_files; sf; sfprev=sf, sf = sf->next)
{
if (sf->ino == buf.st_ino && sf->dev == buf.st_dev)
{
if (sfprev)
sfprev->next = sf->next;
else
secured_files = sf->next;
xfree (sf);
return;
}
}
#endif /*ENABLE_SELINUX_HACKS*/
}
/* Return true if FD is corresponds to a secured file. Using -1 for
FS is allowed and will return false. */
int
is_secured_file (int fd)
{
#ifdef ENABLE_SELINUX_HACKS
struct stat buf;
struct secured_file_item *sf;
if (fd == -1)
return 0; /* No file descriptor so it can't be secured either. */
/* Note that we print out a error here and claim that a file is
secure if something went wrong. */
if (fstat (fd, &buf))
{
log_error (_("fstat(%d) failed in %s: %s\n"), fd,
"is_secured_file", strerror (errno));
return 1;
}
/* log_debug ("is_secured_file (%d) i=%lu.%lu\n", fd, */
/* (unsigned long)buf.st_dev, (unsigned long)buf.st_ino); */
for (sf=secured_files; sf; sf = sf->next)
{
if (sf->ino == buf.st_ino && sf->dev == buf.st_dev)
return 1; /* Yes. */
}
#endif /*ENABLE_SELINUX_HACKS*/
return 0; /* No. */
}
/* Return true if FNAME is corresponds to a secured file. Using NULL,
"" or "-" for FS is allowed and will return false. This function is
used before creating a file, thus it won't fail if the file does
not exist. */
int
is_secured_filename (const char *fname)
{
#ifdef ENABLE_SELINUX_HACKS
struct stat buf;
struct secured_file_item *sf;
if (iobuf_is_pipe_filename (fname) || !*fname)
return 0;
/* Note that we print out a error here and claim that a file is
secure if something went wrong. */
if (stat (fname, &buf))
{
if (errno == ENOENT || errno == EPERM || errno == EACCES)
return 0;
log_error (_("fstat of `%s' failed in %s: %s\n"), fname,
"is_secured_filename", strerror (errno));
return 1;
}
/* log_debug ("is_secured_filename (%s) i=%lu.%lu\n", fname, */
/* (unsigned long)buf.st_dev, (unsigned long)buf.st_ino); */
for (sf=secured_files; sf; sf = sf->next)
{
if (sf->ino == buf.st_ino && sf->dev == buf.st_dev)
return 1; /* Yes. */
}
#endif /*ENABLE_SELINUX_HACKS*/
return 0; /* No. */
}
u16
checksum_u16( unsigned n )
{
u16 a;
a = (n >> 8) & 0xff;
a += n & 0xff;
return a;
}
u16
checksum( byte *p, unsigned n )
{
u16 a;
for(a=0; n; n-- )
a += *p++;
return a;
}
u16
checksum_mpi( MPI a )
{
u16 csum;
byte *buffer;
unsigned nbytes;
unsigned nbits;
buffer = mpi_get_buffer( a, &nbytes, NULL );
nbits = mpi_get_nbits(a);
csum = checksum_u16( nbits );
csum += checksum( buffer, nbytes );
m_free( buffer );
return csum;
}
u32
buffer_to_u32( const byte *buffer )
{
unsigned long a;
a = *buffer << 24;
a |= buffer[1] << 16;
a |= buffer[2] << 8;
a |= buffer[3];
return a;
}
void
print_pubkey_algo_note( int algo )
{
if(algo >= 100 && algo <= 110)
{
static int warn=0;
if(!warn)
{
warn=1;
log_info(_("WARNING: using experimental public key algorithm %s\n"),
pubkey_algo_to_string(algo));
}
}
}
void
print_cipher_algo_note( int algo )
{
if(algo >= 100 && algo <= 110)
{
static int warn=0;
if(!warn)
{
warn=1;
log_info(_("WARNING: using experimental cipher algorithm %s\n"),
cipher_algo_to_string(algo));
}
}
}
void
print_digest_algo_note( int algo )
{
if(algo >= 100 && algo <= 110)
{
static int warn=0;
if(!warn)
{
warn=1;
log_info(_("WARNING: using experimental digest algorithm %s\n"),
digest_algo_to_string(algo));
}
}
else if(algo==DIGEST_ALGO_MD5)
log_info(_("WARNING: digest algorithm %s is deprecated\n"),
digest_algo_to_string(algo));
}
/* Return a string which is used as a kind of process ID */
const byte *
get_session_marker( size_t *rlen )
{
static byte marker[SIZEOF_UNSIGNED_LONG*2];
static int initialized;
if ( !initialized ) {
volatile ulong aa, bb; /* we really want the uninitialized value */
ulong a, b;
initialized = 1;
/* also this marker is guessable it is not easy to use this
* for a faked control packet because an attacker does not
* have enough control about the time the verification does
* take place. Of course, we can add just more random but
* than we need the random generator even for verification
* tasks - which does not make sense. */
a = aa ^ (ulong)getpid();
b = bb ^ (ulong)time(NULL);
memcpy( marker, &a, SIZEOF_UNSIGNED_LONG );
memcpy( marker+SIZEOF_UNSIGNED_LONG, &b, SIZEOF_UNSIGNED_LONG );
}
*rlen = sizeof(marker);
return marker;
}
/****************
* Wrapper around the libgcrypt function with addional checks on
* openPGP contraints for the algo ID.
*/
int
openpgp_cipher_test_algo( int algo )
{
if( algo < 0 || algo > 110 )
return G10ERR_CIPHER_ALGO;
return check_cipher_algo(algo);
}
int
openpgp_pk_test_algo( int algo, unsigned int usage_flags )
{
if( algo < 0 || algo > 110 )
return G10ERR_PUBKEY_ALGO;
return check_pubkey_algo2( algo, usage_flags );
}
int
openpgp_pk_algo_usage ( int algo )
{
int use = 0;
/* they are hardwired in gpg 1.0 */
switch ( algo ) {
case PUBKEY_ALGO_RSA:
use = PUBKEY_USAGE_SIG | PUBKEY_USAGE_ENC | PUBKEY_USAGE_AUTH;
break;
case PUBKEY_ALGO_RSA_E:
use = PUBKEY_USAGE_ENC;
break;
case PUBKEY_ALGO_RSA_S:
use = PUBKEY_USAGE_SIG;
break;
case PUBKEY_ALGO_ELGAMAL_E:
use = PUBKEY_USAGE_ENC;
break;
case PUBKEY_ALGO_DSA:
use = PUBKEY_USAGE_SIG | PUBKEY_USAGE_AUTH;
break;
default:
break;
}
return use;
}
int
openpgp_md_test_algo( int algo )
{
if( algo < 0 || algo > 110 )
return G10ERR_DIGEST_ALGO;
return check_digest_algo(algo);
}
#ifdef USE_IDEA
/* Special warning for the IDEA cipher */
void
idea_cipher_warn(int show)
{
static int warned=0;
if(!warned || show)
{
log_info(_("the IDEA cipher plugin is not present\n"));
log_info(_("please see http://www.gnupg.org/why-not-idea.html "
"for more information\n"));
warned=1;
}
}
#endif
static unsigned long get_signature_count(PKT_secret_key *sk)
{
#ifdef ENABLE_CARD_SUPPORT
if(sk && sk->is_protected && sk->protect.s2k.mode==1002)
{
struct agent_card_info_s info;
if(agent_scd_getattr("SIG-COUNTER",&info)==0)
return info.sig_counter;
}
#endif
/* How to do this without a card? */
return 0;
}
/* Expand %-strings. Returns a string which must be m_freed. Returns
NULL if the string cannot be expanded (too large). */
char *
pct_expando(const char *string,struct expando_args *args)
{
const char *ch=string;
int idx=0,maxlen=0,done=0;
u32 pk_keyid[2]={0,0},sk_keyid[2]={0,0};
char *ret=NULL;
if(args->pk)
keyid_from_pk(args->pk,pk_keyid);
if(args->sk)
keyid_from_sk(args->sk,sk_keyid);
/* This is used so that %k works in photoid command strings in
--list-secret-keys (which of course has a sk, but no pk). */
if(!args->pk && args->sk)
keyid_from_sk(args->sk,pk_keyid);
while(*ch!='\0')
{
char *str=NULL;
if(!done)
{
/* 8192 is way bigger than we'll need here */
if(maxlen>=8192)
goto fail;
maxlen+=1024;
ret=m_realloc(ret,maxlen);
}
done=0;
if(*ch=='%')
{
switch(*(ch+1))
{
case 's': /* short key id */
if(idx+8<maxlen)
{
sprintf(&ret[idx],"%08lX",(ulong)sk_keyid[1]);
idx+=8;
done=1;
}
break;
case 'S': /* long key id */
if(idx+16<maxlen)
{
sprintf(&ret[idx],"%08lX%08lX",
(ulong)sk_keyid[0],(ulong)sk_keyid[1]);
idx+=16;
done=1;
}
break;
case 'k': /* short key id */
if(idx+8<maxlen)
{
sprintf(&ret[idx],"%08lX",(ulong)pk_keyid[1]);
idx+=8;
done=1;
}
break;
case 'K': /* long key id */
if(idx+16<maxlen)
{
sprintf(&ret[idx],"%08lX%08lX",
(ulong)pk_keyid[0],(ulong)pk_keyid[1]);
idx+=16;
done=1;
}
break;
case 'c': /* signature count from card, if any. */
if(idx+10<maxlen)
{
sprintf(&ret[idx],"%lu",get_signature_count(args->sk));
idx+=strlen(&ret[idx]);
done=1;
}
break;
case 'p': /* primary pk fingerprint of a sk */
case 'f': /* pk fingerprint */
case 'g': /* sk fingerprint */
{
byte array[MAX_FINGERPRINT_LEN];
size_t len;
int i;
if((*(ch+1))=='p' && args->sk)
{
if(args->sk->is_primary)
fingerprint_from_sk(args->sk,array,&len);
else if(args->sk->main_keyid[0] || args->sk->main_keyid[1])
{
PKT_public_key *pk=
m_alloc_clear(sizeof(PKT_public_key));
if(get_pubkey_fast(pk,args->sk->main_keyid)==0)
fingerprint_from_pk(pk,array,&len);
else
memset(array,0,(len=MAX_FINGERPRINT_LEN));
free_public_key(pk);
}
else
memset(array,0,(len=MAX_FINGERPRINT_LEN));
}
else if((*(ch+1))=='f' && args->pk)
fingerprint_from_pk(args->pk,array,&len);
else if((*(ch+1))=='g' && args->sk)
fingerprint_from_sk(args->sk,array,&len);
else
memset(array,0,(len=MAX_FINGERPRINT_LEN));
if(idx+(len*2)<maxlen)
{
for(i=0;i<len;i++)
{
sprintf(&ret[idx],"%02X",array[i]);
idx+=2;
}
done=1;
}
}
break;
case 't': /* e.g. "jpg" */
str=image_type_to_string(args->imagetype,0);
/* fall through */
case 'T': /* e.g. "image/jpeg" */
if(str==NULL)
str=image_type_to_string(args->imagetype,2);
if(idx+strlen(str)<maxlen)
{
strcpy(&ret[idx],str);
idx+=strlen(str);
done=1;
}
break;
case '%':
if(idx+1<maxlen)
{
ret[idx++]='%';
ret[idx]='\0';
done=1;
}
break;
/* Any unknown %-keys (like %i, %o, %I, and %O) are
passed through for later expansion. Note this also
handles the case where the last character in the
string is a '%' - the terminating \0 will end up here
and properly terminate the string. */
default:
if(idx+2<maxlen)
{
ret[idx++]='%';
ret[idx++]=*(ch+1);
ret[idx]='\0';
done=1;
}
break;
}
if(done)
ch++;
}
else
{
if(idx+1<maxlen)
{
ret[idx++]=*ch;
ret[idx]='\0';
done=1;
}
}
if(done)
ch++;
}
return ret;
fail:
m_free(ret);
return NULL;
}
void
deprecated_warning(const char *configname,unsigned int configlineno,
const char *option,const char *repl1,const char *repl2)
{
if(configname)
{
if(strncmp("--",option,2)==0)
option+=2;
if(strncmp("--",repl1,2)==0)
repl1+=2;
log_info(_("%s:%d: deprecated option \"%s\"\n"),
configname,configlineno,option);
}
else
log_info(_("WARNING: \"%s\" is a deprecated option\n"),option);
log_info(_("please use \"%s%s\" instead\n"),repl1,repl2);
}
const char *
compress_algo_to_string(int algo)
{
const char *s=NULL;
switch(algo)
{
case COMPRESS_ALGO_NONE:
s=_("Uncompressed");
break;
case COMPRESS_ALGO_ZIP:
s="ZIP";
break;
case COMPRESS_ALGO_ZLIB:
s="ZLIB";
break;
#ifdef HAVE_BZIP2
case COMPRESS_ALGO_BZIP2:
s="BZIP2";
break;
#endif
}
return s;
}
int
string_to_compress_algo(const char *string)
{
/* NOTE TO TRANSLATOR: See doc/TRANSLATE about this string. */
if(match_multistr(_("uncompressed|none"),string))
return 0;
else if(ascii_strcasecmp(string,"uncompressed")==0)
return 0;
else if(ascii_strcasecmp(string,"none")==0)
return 0;
else if(ascii_strcasecmp(string,"zip")==0)
return 1;
else if(ascii_strcasecmp(string,"zlib")==0)
return 2;
#ifdef HAVE_BZIP2
else if(ascii_strcasecmp(string,"bzip2")==0)
return 3;
#endif
else if(ascii_strcasecmp(string,"z0")==0)
return 0;
else if(ascii_strcasecmp(string,"z1")==0)
return 1;
else if(ascii_strcasecmp(string,"z2")==0)
return 2;
#ifdef HAVE_BZIP2
else if(ascii_strcasecmp(string,"z3")==0)
return 3;
#endif
else
return -1;
}
int
check_compress_algo(int algo)
{
#ifdef HAVE_BZIP2
if(algo>=0 && algo<=3)
return 0;
#else
if(algo>=0 && algo<=2)
return 0;
#endif
return G10ERR_COMPR_ALGO;
}
int
default_cipher_algo(void)
{
if(opt.def_cipher_algo)
return opt.def_cipher_algo;
else if(opt.personal_cipher_prefs)
return opt.personal_cipher_prefs[0].value;
else
return opt.s2k_cipher_algo;
}
/* There is no default_digest_algo function, but see
sign.c:hash_for() */
int
default_compress_algo(void)
{
if(opt.compress_algo!=-1)
return opt.compress_algo;
else if(opt.personal_compress_prefs)
return opt.personal_compress_prefs[0].value;
else
return DEFAULT_COMPRESS_ALGO;
}
const char *
compliance_option_string(void)
{
switch(opt.compliance)
{
case CO_RFC2440:
return "--openpgp";
case CO_PGP2:
return "--pgp2";
case CO_PGP6:
return "--pgp6";
case CO_PGP7:
return "--pgp7";
case CO_PGP8:
return "--pgp8";
default:
return "???";
}
}
static const char *
compliance_string(void)
{
switch(opt.compliance)
{
case CO_RFC2440:
return "OpenPGP";
case CO_PGP2:
return "PGP 2.x";
case CO_PGP6:
return "PGP 6.x";
case CO_PGP7:
return "PGP 7.x";
case CO_PGP8:
return "PGP 8.x";
default:
return "???";
}
}
void
compliance_failure(void)
{
log_info(_("this message may not be usable by %s\n"),compliance_string());
opt.compliance=CO_GNUPG;
}
/* Break a string into successive option pieces. Accepts single word
options and key=value argument options. */
char *
optsep(char **stringp)
{
char *tok,*end;
tok=*stringp;
if(tok)
{
end=strpbrk(tok," ,=");
if(end)
{
int sawequals=0;
char *ptr=end;
/* what we need to do now is scan along starting with *end,
If the next character we see (ignoring spaces) is an =
sign, then there is an argument. */
while(*ptr)
{
if(*ptr=='=')
sawequals=1;
else if(*ptr!=' ')
break;
ptr++;
}
/* There is an argument, so grab that too. At this point,
ptr points to the first character of the argument. */
if(sawequals)
{
/* Is it a quoted argument? */
if(*ptr=='"')
{
ptr++;
end=strchr(ptr,'"');
if(end)
end++;
}
else
end=strpbrk(ptr," ,");
}
if(end && *end)
{
*end='\0';
*stringp=end+1;
}
else
*stringp=NULL;
}
else
*stringp=NULL;
}
return tok;
}
/* Breaks an option value into key and value. Returns NULL if there
is no value. Note that "string" is modified to remove the =value
part. */
char *
argsplit(char *string)
{
char *equals,*arg=NULL;
equals=strchr(string,'=');
if(equals)
{
char *quote,*space;
*equals='\0';
arg=equals+1;
/* Quoted arg? */
quote=strchr(arg,'"');
if(quote)
{
arg=quote+1;
quote=strchr(arg,'"');
if(quote)
*quote='\0';
}
else
{
size_t spaces;
/* Trim leading spaces off of the arg */
spaces=strspn(arg," ");
arg+=spaces;
}
/* Trim tailing spaces off of the tag */
space=strchr(string,' ');
if(space)
*space='\0';
}
return arg;
}
/* Return the length of the initial token, leaving off any
argument. */
static size_t
optlen(const char *s)
{
char *end=strpbrk(s," =");
if(end)
return end-s;
else
return strlen(s);
}
int
parse_options(char *str,unsigned int *options,
struct parse_options *opts,int noisy)
{
char *tok;
while((tok=optsep(&str)))
{
int i,rev=0;
char *otok=tok;
if(tok[0]=='\0')
continue;
if(ascii_strncasecmp("no-",tok,3)==0)
{
rev=1;
tok+=3;
}
for(i=0;opts[i].name;i++)
{
size_t toklen=optlen(tok);
if(ascii_strncasecmp(opts[i].name,tok,toklen)==0)
{
/* We have a match, but it might be incomplete */
if(toklen!=strlen(opts[i].name))
{
int j;
for(j=i+1;opts[j].name;j++)
{
if(ascii_strncasecmp(opts[j].name,tok,toklen)==0)
{
if(noisy)
log_info(_("ambiguous option `%s'\n"),otok);
return 0;
}
}
}
if(rev)
{
*options&=~opts[i].bit;
if(opts[i].value)
*opts[i].value=NULL;
}
else
{
*options|=opts[i].bit;
if(opts[i].value)
*opts[i].value=argsplit(tok);
}
break;
}
}
if(!opts[i].name)
{
if(noisy)
log_info(_("unknown option `%s'\n"),otok);
return 0;
}
}
return 1;
}
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