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gnupg/g10/keyid.c
Werner Koch 4659c923a0 Sample ECC keys and message do now work.
Import and export of secret keys does now work.  Encryption has been
fixed to be compatible with the sample messages.

This version tests for new Libgcrypt function and thus needs to be
build with a new Libgcrypt installed.
2011-02-02 15:48:54 +01:00

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/* keyid.c - key ID and fingerprint handling
* Copyright (C) 1998, 1999, 2000, 2001, 2003,
* 2004, 2006, 2010 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* GnuPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* GnuPG is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <time.h>
#include <assert.h>
#include "gpg.h"
#include "util.h"
#include "main.h"
#include "packet.h"
#include "options.h"
#include "keydb.h"
#include "i18n.h"
#include "rmd160.h"
#define KEYID_STR_SIZE 19
#ifdef HAVE_UNSIGNED_TIME_T
# define IS_INVALID_TIME_T(a) ((a) == (time_t)(-1))
#else
/* Error or 32 bit time_t and value after 2038-01-19. */
# define IS_INVALID_TIME_T(a) ((a) < 0)
#endif
/* Return a letter describing the public key algorithms. */
int
pubkey_letter( int algo )
{
switch (algo)
{
case PUBKEY_ALGO_RSA: return 'R' ;
case PUBKEY_ALGO_RSA_E: return 'r' ;
case PUBKEY_ALGO_RSA_S: return 's' ;
case PUBKEY_ALGO_ELGAMAL_E: return 'g' ;
case PUBKEY_ALGO_ELGAMAL: return 'G' ;
case PUBKEY_ALGO_DSA: return 'D' ;
case PUBKEY_ALGO_ECDSA: return 'E' ; /* ECC DSA (sign only) */
case PUBKEY_ALGO_ECDH: return 'e' ; /* ECC DH (encrypt only) */
default: return '?';
}
}
/* Hash a public key. This function is useful for v4 fingerprints and
for v3 or v4 key signing. */
void
hash_public_key (gcry_md_hd_t md, PKT_public_key *pk)
{
unsigned int n = 6;
unsigned int nn[PUBKEY_MAX_NPKEY];
byte *pp[PUBKEY_MAX_NPKEY];
int i;
unsigned int nbits;
size_t nbytes;
int npkey = pubkey_get_npkey (pk->pubkey_algo);
/* Two extra bytes for the expiration date in v3 */
if(pk->version<4)
n+=2;
/* FIXME: We can avoid the extra malloc by calling only the first
mpi_print here which computes the required length and calling the
real mpi_print only at the end. The speed advantage would only be
for ECC (opaque MPIs) or if we could implement an mpi_print
variant with a callback handler to do the hashing. */
if (npkey==0 && pk->pkey[0]
&& gcry_mpi_get_flag (pk->pkey[0], GCRYMPI_FLAG_OPAQUE))
{
pp[0] = gcry_mpi_get_opaque (pk->pkey[0], &nbits);
nn[0] = (nbits+7)/8;
n+=nn[0];
}
else
{
for (i=0; i < npkey; i++ )
{
if (gcry_mpi_get_flag (pk->pkey[i], GCRYMPI_FLAG_OPAQUE))
{
size_t nbits;
const void *p;
p = gcry_mpi_get_opaque (pk->pkey[i], &nbits);
pp[i] = xmalloc ((nbits+7)/8);
memcpy (pp[i], p, (nbits+7)/8);
nn[i] = (nbits+7)/8;
n += nn[i];
}
else
{
if (gcry_mpi_print (GCRYMPI_FMT_PGP, NULL, 0,
&nbytes, pk->pkey[i]))
BUG ();
pp[i] = xmalloc (nbytes);
if (gcry_mpi_print (GCRYMPI_FMT_PGP, pp[i], nbytes,
&nbytes, pk->pkey[i]))
BUG ();
nn[i] = nbytes;
n += nn[i];
}
}
}
gcry_md_putc ( md, 0x99 ); /* ctb */
/* What does it mean if n is greater than than 0xFFFF ? */
gcry_md_putc ( md, n >> 8 ); /* 2 byte length header */
gcry_md_putc ( md, n );
gcry_md_putc ( md, pk->version );
gcry_md_putc ( md, pk->timestamp >> 24 );
gcry_md_putc ( md, pk->timestamp >> 16 );
gcry_md_putc ( md, pk->timestamp >> 8 );
gcry_md_putc ( md, pk->timestamp );
if(pk->version<4)
{
u16 days=0;
if(pk->expiredate)
days=(u16)((pk->expiredate - pk->timestamp) / 86400L);
gcry_md_putc ( md, days >> 8 );
gcry_md_putc ( md, days );
}
gcry_md_putc ( md, pk->pubkey_algo );
if(npkey==0 && pk->pkey[0]
&& gcry_mpi_get_flag (pk->pkey[0], GCRYMPI_FLAG_OPAQUE))
{
gcry_md_write (md, pp[0], nn[0]);
}
else
for(i=0; i < npkey; i++ )
{
gcry_md_write ( md, pp[i], nn[i] );
xfree(pp[i]);
}
}
static gcry_md_hd_t
do_fingerprint_md( PKT_public_key *pk )
{
gcry_md_hd_t md;
if (gcry_md_open (&md, DIGEST_ALGO_SHA1, 0))
BUG ();
hash_public_key(md,pk);
gcry_md_final( md );
return md;
}
/* fixme: Check whether we can replace this function or if not
describe why we need it. */
u32
v3_keyid (gcry_mpi_t a, u32 *ki)
{
byte *buffer, *p;
size_t nbytes;
if (gcry_mpi_print (GCRYMPI_FMT_USG, NULL, 0, &nbytes, a ))
BUG ();
/* fixme: allocate it on the stack */
buffer = xmalloc (nbytes);
if (gcry_mpi_print( GCRYMPI_FMT_USG, buffer, nbytes, NULL, a ))
BUG ();
if (nbytes < 8) /* oops */
ki[0] = ki[1] = 0;
else
{
p = buffer + nbytes - 8;
ki[0] = (p[0] << 24) | (p[1] <<16) | (p[2] << 8) | p[3];
p += 4;
ki[1] = (p[0] << 24) | (p[1] <<16) | (p[2] << 8) | p[3];
}
xfree (buffer);
return ki[1];
}
size_t
keystrlen(void)
{
switch(opt.keyid_format)
{
case KF_SHORT:
return 8;
case KF_LONG:
return 16;
case KF_0xSHORT:
return 10;
case KF_0xLONG:
return 18;
default:
BUG();
}
}
const char *
keystr (u32 *keyid)
{
static char keyid_str[KEYID_STR_SIZE];
switch (opt.keyid_format)
{
case KF_SHORT:
snprintf (keyid_str, sizeof keyid_str, "%08lX", (ulong)keyid[1]);
break;
case KF_LONG:
if (keyid[0])
snprintf (keyid_str, sizeof keyid_str, "%08lX%08lX",
(ulong)keyid[0], (ulong)keyid[1]);
else
snprintf (keyid_str, sizeof keyid_str, "%08lX", (ulong)keyid[1]);
break;
case KF_0xSHORT:
snprintf (keyid_str, sizeof keyid_str, "0x%08lX", (ulong)keyid[1]);
break;
case KF_0xLONG:
if(keyid[0])
snprintf (keyid_str, sizeof keyid_str, "0x%08lX%08lX",
(ulong)keyid[0],(ulong)keyid[1]);
else
snprintf (keyid_str, sizeof keyid_str, "0x%08lX", (ulong)keyid[1]);
break;
default:
BUG();
}
return keyid_str;
}
const char *
keystr_with_sub (u32 *main_kid, u32 *sub_kid)
{
static char buffer[KEYID_STR_SIZE+1+KEYID_STR_SIZE];
char *p;
mem2str (buffer, keystr (main_kid), KEYID_STR_SIZE);
if (sub_kid)
{
p = buffer + strlen (buffer);
*p++ = '/';
mem2str (p, keystr (sub_kid), KEYID_STR_SIZE);
}
return buffer;
}
const char *
keystr_from_pk(PKT_public_key *pk)
{
keyid_from_pk(pk,NULL);
return keystr(pk->keyid);
}
const char *
keystr_from_pk_with_sub (PKT_public_key *main_pk, PKT_public_key *sub_pk)
{
keyid_from_pk (main_pk, NULL);
if (sub_pk)
keyid_from_pk (sub_pk, NULL);
return keystr_with_sub (main_pk->keyid, sub_pk? sub_pk->keyid:NULL);
}
const char *
keystr_from_desc(KEYDB_SEARCH_DESC *desc)
{
switch(desc->mode)
{
case KEYDB_SEARCH_MODE_LONG_KID:
case KEYDB_SEARCH_MODE_SHORT_KID:
return keystr(desc->u.kid);
case KEYDB_SEARCH_MODE_FPR20:
{
u32 keyid[2];
keyid[0] = ((unsigned char)desc->u.fpr[12] << 24
| (unsigned char)desc->u.fpr[13] << 16
| (unsigned char)desc->u.fpr[14] << 8
| (unsigned char)desc->u.fpr[15]);
keyid[1] = ((unsigned char)desc->u.fpr[16] << 24
| (unsigned char)desc->u.fpr[17] << 16
| (unsigned char)desc->u.fpr[18] << 8
| (unsigned char)desc->u.fpr[19]);
return keystr(keyid);
}
case KEYDB_SEARCH_MODE_FPR16:
return "?v3 fpr?";
default:
BUG();
}
}
/*
* Get the keyid from the public key and put it into keyid
* if this is not NULL. Return the 32 low bits of the keyid.
*/
u32
keyid_from_pk (PKT_public_key *pk, u32 *keyid)
{
u32 lowbits;
u32 dummy_keyid[2];
if (!keyid)
keyid = dummy_keyid;
if( pk->keyid[0] || pk->keyid[1] )
{
keyid[0] = pk->keyid[0];
keyid[1] = pk->keyid[1];
lowbits = keyid[1];
}
else if( pk->version < 4 )
{
if( is_RSA(pk->pubkey_algo) )
{
lowbits = (pubkey_get_npkey (pk->pubkey_algo) ?
v3_keyid ( pk->pkey[0], keyid ) : 0); /* From n. */
pk->keyid[0] = keyid[0];
pk->keyid[1] = keyid[1];
}
else
pk->keyid[0]=pk->keyid[1]=keyid[0]=keyid[1]=lowbits=0xFFFFFFFF;
}
else
{
const byte *dp;
gcry_md_hd_t md;
md = do_fingerprint_md(pk);
if(md)
{
dp = gcry_md_read ( md, 0 );
keyid[0] = dp[12] << 24 | dp[13] << 16 | dp[14] << 8 | dp[15] ;
keyid[1] = dp[16] << 24 | dp[17] << 16 | dp[18] << 8 | dp[19] ;
lowbits = keyid[1];
gcry_md_close (md);
pk->keyid[0] = keyid[0];
pk->keyid[1] = keyid[1];
}
else
pk->keyid[0]=pk->keyid[1]=keyid[0]=keyid[1]=lowbits=0xFFFFFFFF;
}
return lowbits;
}
/*
* Get the keyid from the fingerprint. This function is simple for most
* keys, but has to do a keylookup for old stayle keys.
*/
u32
keyid_from_fingerprint( const byte *fprint, size_t fprint_len, u32 *keyid )
{
u32 dummy_keyid[2];
if( !keyid )
keyid = dummy_keyid;
if (fprint_len != 20)
{
/* This is special as we have to lookup the key first. */
PKT_public_key pk;
int rc;
memset (&pk, 0, sizeof pk);
rc = get_pubkey_byfprint (&pk, fprint, fprint_len);
if( rc )
{
log_error("Oops: keyid_from_fingerprint: no pubkey\n");
keyid[0] = 0;
keyid[1] = 0;
}
else
keyid_from_pk (&pk, keyid);
}
else
{
const byte *dp = fprint;
keyid[0] = dp[12] << 24 | dp[13] << 16 | dp[14] << 8 | dp[15] ;
keyid[1] = dp[16] << 24 | dp[17] << 16 | dp[18] << 8 | dp[19] ;
}
return keyid[1];
}
u32
keyid_from_sig (PKT_signature *sig, u32 *keyid)
{
if( keyid )
{
keyid[0] = sig->keyid[0];
keyid[1] = sig->keyid[1];
}
return sig->keyid[1];
}
byte *
namehash_from_uid (PKT_user_id *uid)
{
if (!uid->namehash)
{
uid->namehash = xmalloc (20);
if (uid->attrib_data)
rmd160_hash_buffer (uid->namehash, uid->attrib_data, uid->attrib_len);
else
rmd160_hash_buffer (uid->namehash, uid->name, uid->len);
}
return uid->namehash;
}
/*
* Return the number of bits used in PK.
*/
unsigned int
nbits_from_pk (PKT_public_key *pk)
{
return pubkey_nbits (pk->pubkey_algo, pk->pkey);
}
static const char *
mk_datestr (char *buffer, time_t atime)
{
struct tm *tp;
if (IS_INVALID_TIME_T (atime))
strcpy (buffer, "????" "-??" "-??"); /* Mark this as invalid. */
else
{
tp = gmtime (&atime);
sprintf (buffer,"%04d-%02d-%02d",
1900+tp->tm_year, tp->tm_mon+1, tp->tm_mday );
}
return buffer;
}
/*
* return a string with the creation date of the pk
* Note: this is alloced in a static buffer.
* Format is: yyyy-mm-dd
*/
const char *
datestr_from_pk (PKT_public_key *pk)
{
static char buffer[11+5];
time_t atime = pk->timestamp;
return mk_datestr (buffer, atime);
}
const char *
datestr_from_sig (PKT_signature *sig )
{
static char buffer[11+5];
time_t atime = sig->timestamp;
return mk_datestr (buffer, atime);
}
const char *
expirestr_from_pk (PKT_public_key *pk)
{
static char buffer[11+5];
time_t atime;
if (!pk->expiredate)
return _("never ");
atime = pk->expiredate;
return mk_datestr (buffer, atime);
}
const char *
expirestr_from_sig (PKT_signature *sig)
{
static char buffer[11+5];
time_t atime;
if (!sig->expiredate)
return _("never ");
atime=sig->expiredate;
return mk_datestr (buffer, atime);
}
const char *
revokestr_from_pk( PKT_public_key *pk )
{
static char buffer[11+5];
time_t atime;
if(!pk->revoked.date)
return _("never ");
atime=pk->revoked.date;
return mk_datestr (buffer, atime);
}
const char *
usagestr_from_pk( PKT_public_key *pk )
{
static char buffer[10];
int i = 0;
unsigned int use = pk->pubkey_usage;
if ( use & PUBKEY_USAGE_SIG )
buffer[i++] = 'S';
if ( use & PUBKEY_USAGE_CERT )
buffer[i++] = 'C';
if ( use & PUBKEY_USAGE_ENC )
buffer[i++] = 'E';
if ( (use & PUBKEY_USAGE_AUTH) )
buffer[i++] = 'A';
while (i < 4)
buffer[i++] = ' ';
buffer[i] = 0;
return buffer;
}
const char *
colon_strtime (u32 t)
{
static char buf[20];
if (!t)
return "";
snprintf (buf, sizeof buf, "%lu", (ulong)t);
return buf;
}
const char *
colon_datestr_from_pk (PKT_public_key *pk)
{
static char buf[20];
snprintf (buf, sizeof buf, "%lu", (ulong)pk->timestamp);
return buf;
}
const char *
colon_datestr_from_sig (PKT_signature *sig)
{
static char buf[20];
snprintf (buf, sizeof buf, "%lu", (ulong)sig->timestamp);
return buf;
}
const char *
colon_expirestr_from_sig (PKT_signature *sig)
{
static char buf[20];
if (!sig->expiredate)
return "";
snprintf (buf, sizeof buf,"%lu", (ulong)sig->expiredate);
return buf;
}
/*
* Return a byte array with the fingerprint for the given PK/SK
* The length of the array is returned in ret_len. Caller must free
* the array or provide an array of length MAX_FINGERPRINT_LEN.
*/
byte *
fingerprint_from_pk (PKT_public_key *pk, byte *array, size_t *ret_len)
{
byte *buf;
const byte *dp;
size_t len, nbytes;
int i;
if ( pk->version < 4 )
{
if ( is_RSA(pk->pubkey_algo) )
{
/* RSA in version 3 packets is special. */
gcry_md_hd_t md;
if (gcry_md_open (&md, DIGEST_ALGO_MD5, 0))
BUG ();
if ( pubkey_get_npkey (pk->pubkey_algo) > 1 )
{
for (i=0; i < 2; i++)
{
if (gcry_mpi_print (GCRYMPI_FMT_USG, NULL, 0,
&nbytes, pk->pkey[i]))
BUG ();
/* fixme: Better allocate BUF on the stack */
buf = xmalloc (nbytes);
if (gcry_mpi_print (GCRYMPI_FMT_USG, buf, nbytes,
NULL, pk->pkey[i]))
BUG ();
gcry_md_write (md, buf, nbytes);
xfree (buf);
}
}
gcry_md_final (md);
if (!array)
array = xmalloc (16);
len = 16;
memcpy (array, gcry_md_read (md, DIGEST_ALGO_MD5), 16);
gcry_md_close(md);
}
else
{
if (!array)
array = xmalloc(16);
len = 16;
memset (array,0,16);
}
}
else
{
gcry_md_hd_t md;
md = do_fingerprint_md(pk);
dp = gcry_md_read( md, 0 );
len = gcry_md_get_algo_dlen (gcry_md_get_algo (md));
assert( len <= MAX_FINGERPRINT_LEN );
if (!array)
array = xmalloc ( len );
memcpy (array, dp, len );
pk->keyid[0] = dp[12] << 24 | dp[13] << 16 | dp[14] << 8 | dp[15] ;
pk->keyid[1] = dp[16] << 24 | dp[17] << 16 | dp[18] << 8 | dp[19] ;
gcry_md_close( md);
}
*ret_len = len;
return array;
}
/* Return the so called KEYGRIP which is the SHA-1 hash of the public
key parameters expressed as an canoncial encoded S-Exp. ARRAY must
be 20 bytes long. Returns 0 on sucess or an error code. */
gpg_error_t
keygrip_from_pk (PKT_public_key *pk, unsigned char *array)
{
gpg_error_t err;
gcry_sexp_t s_pkey;
if (DBG_PACKET)
log_debug ("get_keygrip for public key\n");
switch (pk->pubkey_algo)
{
case GCRY_PK_DSA:
err = gcry_sexp_build (&s_pkey, NULL,
"(public-key(dsa(p%m)(q%m)(g%m)(y%m)))",
pk->pkey[0], pk->pkey[1],
pk->pkey[2], pk->pkey[3]);
break;
case GCRY_PK_ELG:
case GCRY_PK_ELG_E:
err = gcry_sexp_build (&s_pkey, NULL,
"(public-key(elg(p%m)(g%m)(y%m)))",
pk->pkey[0], pk->pkey[1], pk->pkey[2]);
break;
case GCRY_PK_RSA:
case GCRY_PK_RSA_S:
case GCRY_PK_RSA_E:
err = gcry_sexp_build (&s_pkey, NULL,
"(public-key(rsa(n%m)(e%m)))",
pk->pkey[0], pk->pkey[1]);
break;
case PUBKEY_ALGO_ECDSA:
case PUBKEY_ALGO_ECDH:
{
char *curve = openpgp_oid_to_str (pk->pkey[0]);
if (!curve)
err = gpg_error_from_syserror ();
else
{
err = gcry_sexp_build (&s_pkey, NULL,
"(public-key(ecc(curve%s)(q%m)))",
curve, pk->pkey[1]);
xfree (curve);
}
}
break;
default:
err = gpg_error (GPG_ERR_PUBKEY_ALGO);
break;
}
if (err)
return err;
if (!gcry_pk_get_keygrip (s_pkey, array))
{
log_error ("error computing keygrip\n");
err = gpg_error (GPG_ERR_GENERAL);
}
else
{
if (DBG_PACKET)
log_printhex ("keygrip=", array, 20);
/* FIXME: Save the keygrip in PK. */
}
gcry_sexp_release (s_pkey);
return 0;
}
/* Store an allocated buffer with the keygrip of PK encoded as a
hexstring at r_GRIP. Returns 0 on success. */
gpg_error_t
hexkeygrip_from_pk (PKT_public_key *pk, char **r_grip)
{
gpg_error_t err;
unsigned char grip[20];
*r_grip = NULL;
err = keygrip_from_pk (pk, grip);
if (!err)
{
char * buf = xtrymalloc (20*2+1);
if (!buf)
err = gpg_error_from_syserror ();
else
{
bin2hex (grip, 20, buf);
*r_grip = buf;
}
}
return err;
}