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gnupg/g10/misc.c

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/* misc.c - miscellaneous functions
* 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 <unistd.h>
#include <errno.h>
#include <assert.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
#include "gpg.h"
#include "util.h"
#include "main.h"
#include "photoid.h"
#include "options.h"
#include "i18n.h"
#define MAX_EXTERN_MPI_BITS 16384
#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
}
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( gcry_mpi_t a )
{
int rc;
u16 csum;
byte *buffer;
size_t nbytes;
rc = gcry_mpi_print( GCRYMPI_FMT_PGP, NULL, 0, &nbytes, a );
if (rc)
BUG ();
/* fixme: for numbers not in secure memory we should use a stack
* based buffer and only allocate a larger one if mpi_print return
* an error */
buffer = gcry_is_secure(a)? gcry_xmalloc_secure(nbytes):gcry_xmalloc(nbytes);
rc = gcry_mpi_print (GCRYMPI_FMT_PGP, buffer, nbytes, NULL, a );
if (rc)
BUG ();
csum = checksum (buffer, nbytes );
xfree (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;
}
static void
no_exp_algo(void)
{
static int did_note = 0;
if( !did_note ) {
did_note = 1;
log_info(_("Experimental algorithms should not be used!\n"));
}
}
void
print_pubkey_algo_note( int algo )
{
if( algo >= 100 && algo <= 110 )
no_exp_algo();
}
void
print_cipher_algo_note( int algo )
{
if( algo >= 100 && algo <= 110 )
no_exp_algo();
else if( algo == CIPHER_ALGO_3DES
|| algo == CIPHER_ALGO_CAST5
|| algo == CIPHER_ALGO_BLOWFISH
|| algo == CIPHER_ALGO_TWOFISH
|| algo == CIPHER_ALGO_RIJNDAEL
|| algo == CIPHER_ALGO_RIJNDAEL192
|| algo == CIPHER_ALGO_RIJNDAEL256
)
;
else {
static int did_note = 0;
if( !did_note ) {
did_note = 1;
log_info(_("this cipher algorithm is deprecated; "
"please use a more standard one!\n"));
}
}
}
void
print_digest_algo_note( int algo )
{
if( algo >= 100 && algo <= 110 )
no_exp_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 GPG_ERR_CIPHER_ALGO;
return gcry_cipher_test_algo (algo);
}
int
openpgp_pk_test_algo( int algo, unsigned int usage_flags )
{
size_t value = usage_flags;
if (algo == GCRY_PK_ELG_E)
algo = GCRY_PK_ELG;
#ifdef __GNUC__
#warning need to handle the usage here?
#endif
if (algo < 0 || algo > 110)
return GPG_ERR_PUBKEY_ALGO;
return gcry_pk_algo_info (algo, GCRYCTL_TEST_ALGO, NULL, &value);
}
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;
case PUBKEY_ALGO_ELGAMAL:
use = PUBKEY_USAGE_SIG | PUBKEY_USAGE_ENC | PUBKEY_USAGE_AUTH;
break;
default:
break;
}
return use;
}
int
openpgp_md_test_algo( int algo )
{
if( algo < 0 || algo > 110 )
return GPG_ERR_DIGEST_ALGO;
return gcry_md_test_algo (algo);
}
int
openpgp_md_map_name (const char *string)
{
int i = gcry_md_map_name (string);
if (!i && (string[0]=='H' || string[0]=='h'))
{ /* Didn't find it, so try the Hx format */
long val;
char *endptr;
string++;
val=strtol(string,&endptr,10);
if (*string!='\0' && *endptr=='\0' && !openpgp_md_test_algo(val))
i = val;
}
return i < 0 || i > 110? 0 : i;
}
int
openpgp_cipher_map_name (const char *string)
{
int i = gcry_cipher_map_name (string);
if (!i && (string[0]=='S' || string[0]=='s'))
{ /* Didn't find it, so try the Sx format */
long val;
char *endptr;
string++;
val=strtol(string,&endptr,10);
if (*string!='\0' && *endptr=='\0' && !openpgp_cipher_test_algo(val))
i = val;
}
return i < 0 || i > 110? 0 : i;
}
int
openpgp_pk_map_name (const char *string)
{
int i = gcry_pk_map_name (string);
return i < 0 || i > 110? 0 : i;
}
#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
/* 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= xrealloc(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 '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= xcalloc(1, 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:
xfree (ret);
return NULL;
}
int
hextobyte( const char *s )
{
int c;
if( *s >= '0' && *s <= '9' )
c = 16 * (*s - '0');
else if( *s >= 'A' && *s <= 'F' )
c = 16 * (10 + *s - 'A');
else if( *s >= 'a' && *s <= 'f' )
c = 16 * (10 + *s - 'a');
else
return -1;
s++;
if( *s >= '0' && *s <= '9' )
c += *s - '0';
else if( *s >= 'A' && *s <= 'F' )
c += 10 + *s - 'A';
else if( *s >= 'a' && *s <= 'f' )
c += 10 + *s - 'a';
else
return -1;
return c;
}
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="?";
switch(algo)
{
case 0:
s="Uncompressed";
break;
case 1:
s="ZIP";
break;
case 2:
s="ZLIB";
break;
}
return s;
}
int
string_to_compress_algo(const char *string)
{
if(ascii_strcasecmp(string,"uncompressed")==0)
return 0;
else if(ascii_strcasecmp(string,"zip")==0)
return 1;
else if(ascii_strcasecmp(string,"zlib")==0)
return 2;
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;
else
return -1;
}
int
check_compress_algo(int algo)
{
if(algo>=0 && algo<=2)
return 0;
return GPG_ERR_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.def_compress_algo!=-1)
return opt.def_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;
}
int
parse_options(char *str,unsigned int *options,struct parse_options *opts)
{
char *tok;
while((tok=strsep(&str," ,")))
{
int i,rev=0;
if(tok[0]=='\0')
continue;
if(ascii_strncasecmp("no-",tok,3)==0)
{
rev=1;
tok+=3;
}
for(i=0;opts[i].name;i++)
{
if(ascii_strcasecmp(opts[i].name,tok)==0)
{
if(rev)
*options&=~opts[i].bit;
else
*options|=opts[i].bit;
break;
}
}
if(!opts[i].name)
return 0;
}
return 1;
}
/* Temporary helper. */
int
pubkey_get_npkey( int algo )
{
size_t n;
if (algo == GCRY_PK_ELG_E)
algo = GCRY_PK_ELG;
if (gcry_pk_algo_info( algo, GCRYCTL_GET_ALGO_NPKEY, NULL, &n))
n = 0;
return n;
}
/* Temporary helper. */
int
pubkey_get_nskey( int algo )
{
size_t n;
if (algo == GCRY_PK_ELG_E)
algo = GCRY_PK_ELG;
if (gcry_pk_algo_info( algo, GCRYCTL_GET_ALGO_NSKEY, NULL, &n ))
n = 0;
return n;
}
/* Temporary helper. */
int
pubkey_get_nsig( int algo )
{
size_t n;
if (algo == GCRY_PK_ELG_E)
algo = GCRY_PK_ELG;
if (gcry_pk_algo_info( algo, GCRYCTL_GET_ALGO_NSIGN, NULL, &n))
n = 0;
return n;
}
/* Temporary helper. */
int
pubkey_get_nenc( int algo )
{
size_t n;
if (algo == GCRY_PK_ELG_E)
algo = GCRY_PK_ELG;
if (gcry_pk_algo_info( algo, GCRYCTL_GET_ALGO_NENCR, NULL, &n ))
n = 0;
return n;
}
/* Temporary helper. */
unsigned int
pubkey_nbits( int algo, gcry_mpi_t *key )
{
int rc, nbits;
gcry_sexp_t sexp;
if( algo == GCRY_PK_DSA ) {
rc = gcry_sexp_build ( &sexp, NULL,
"(public-key(dsa(p%m)(q%m)(g%m)(y%m)))",
key[0], key[1], key[2], key[3] );
}
else if( algo == GCRY_PK_ELG || algo == GCRY_PK_ELG_E ) {
rc = gcry_sexp_build ( &sexp, NULL,
"(public-key(elg(p%m)(g%m)(y%m)))",
key[0], key[1], key[2] );
}
else if( algo == GCRY_PK_RSA ) {
rc = gcry_sexp_build ( &sexp, NULL,
"(public-key(rsa(n%m)(e%m)))",
key[0], key[1] );
}
else
return 0;
if ( rc )
BUG ();
nbits = gcry_pk_get_nbits( sexp );
gcry_sexp_release( sexp );
return nbits;
}
/* MPI helper functions. */
/****************
* write an mpi to out.
*/
int
mpi_write( iobuf_t out, gcry_mpi_t a )
{
char buffer[(MAX_EXTERN_MPI_BITS+7)/8];
size_t nbytes;
int rc;
nbytes = (MAX_EXTERN_MPI_BITS+7)/8;
rc = gcry_mpi_print (GCRYMPI_FMT_PGP, buffer, nbytes, &nbytes, a );
if( !rc )
rc = iobuf_write( out, buffer, nbytes );
return rc;
}
/****************
* Writyeg a MPI to out, but in this case it is an opaque one,
* s used vor v3 protected keys.
*/
int
mpi_write_opaque( iobuf_t out, gcry_mpi_t a )
{
size_t nbytes, nbits;
int rc;
char *p;
assert( gcry_mpi_get_flag( a, GCRYMPI_FLAG_OPAQUE ) );
p = gcry_mpi_get_opaque( a, &nbits );
nbytes = (nbits+7) / 8;
iobuf_put( out, nbits >> 8 );
iobuf_put( out, nbits );
rc = iobuf_write( out, p, nbytes );
return rc;
}
/****************
* Read an external representation of an mpi and return the MPI
* The external format is a 16 bit unsigned value stored in network byte order,
* giving the number of bits for the following integer. The integer is stored
* with MSB first (left padded with zeroes to align on a byte boundary).
*/
gcry_mpi_t
mpi_read(iobuf_t inp, unsigned int *ret_nread, int secure)
{
int c, c1, c2, i;
unsigned int nbits, nbytes, nread=0;
gcry_mpi_t a = NULL;
byte *buf = NULL;
byte *p;
if( (c = c1 = iobuf_get(inp)) == -1 )
goto leave;
nbits = c << 8;
if( (c = c2 = iobuf_get(inp)) == -1 )
goto leave;
nbits |= c;
if( nbits > MAX_EXTERN_MPI_BITS ) {
log_error("mpi too large (%u bits)\n", nbits);
goto leave;
}
nread = 2;
nbytes = (nbits+7) / 8;
buf = secure? gcry_xmalloc_secure( nbytes+2 ) : gcry_xmalloc( nbytes+2 );
p = buf;
p[0] = c1;
p[1] = c2;
for( i=0 ; i < nbytes; i++ ) {
p[i+2] = iobuf_get(inp) & 0xff;
nread++;
}
nread += nbytes;
if( gcry_mpi_scan( &a, GCRYMPI_FMT_PGP, buf, nread, &nread ) )
a = NULL;
leave:
gcry_free(buf);
if( nread > *ret_nread )
log_bug("mpi larger than packet");
else
*ret_nread = nread;
return a;
}
/****************
* Same as mpi_read but the value is stored as an opaque MPI.
* This function is used to read encrypted MPI of v3 packets.
*/
gcry_mpi_t
mpi_read_opaque(iobuf_t inp, unsigned *ret_nread )
{
int c, c1, c2, i;
unsigned nbits, nbytes, nread=0;
gcry_mpi_t a = NULL;
byte *buf = NULL;
byte *p;
if( (c = c1 = iobuf_get(inp)) == -1 )
goto leave;
nbits = c << 8;
if( (c = c2 = iobuf_get(inp)) == -1 )
goto leave;
nbits |= c;
if( nbits > MAX_EXTERN_MPI_BITS ) {
log_error("mpi too large (%u bits)\n", nbits);
goto leave;
}
nread = 2;
nbytes = (nbits+7) / 8;
buf = gcry_xmalloc( nbytes );
p = buf;
for( i=0 ; i < nbytes; i++ ) {
p[i] = iobuf_get(inp) & 0xff;
}
nread += nbytes;
a = gcry_mpi_set_opaque(NULL, buf, nbits );
buf = NULL;
leave:
gcry_free(buf);
if( nread > *ret_nread )
log_bug("mpi larger than packet");
else
*ret_nread = nread;
return a;
}
int
mpi_print( FILE *fp, gcry_mpi_t a, int mode )
{
int n=0;
if( !a )
return fprintf(fp, "[MPI_NULL]");
if( !mode ) {
unsigned int n1;
n1 = gcry_mpi_get_nbits(a);
n += fprintf(fp, "[%u bits]", n1);
}
else {
int rc;
char *buffer;
rc = gcry_mpi_aprint( GCRYMPI_FMT_HEX,
&(unsigned char*)buffer, NULL, a );
assert( !rc );
fputs( buffer, fp );
n += strlen(buffer);
gcry_free( buffer );
}
return n;
}
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