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gnupg/g10/getkey.c

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/* getkey.c - Get a key from the database
* Copyright (c) 1997 by Werner Koch (dd9jn)
*
* This file is part of G10.
*
* G10 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.
*
* G10 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 <assert.h>
#include <ctype.h>
#include "util.h"
#include "packet.h"
#include "memory.h"
#include "iobuf.h"
#include "keydb.h"
#include "options.h"
#define MAX_PKC_CACHE_ENTRIES 500
typedef struct keyid_list {
struct keyid_list *next;
u32 keyid[2];
} *keyid_list_t;
typedef struct user_id_db {
struct user_id_db *next;
u32 keyid[2];
int len;
char name[1];
} *user_id_db_t;
typedef struct pkc_cache_entry {
struct pkc_cache_entry *next;
u32 keyid[2];
PKT_public_cert *pkc;
} *pkc_cache_entry_t;
typedef struct enum_seckey_context {
int eof;
STRLIST sl;
IOBUF iobuf;
} enum_seckey_context_t;
static STRLIST keyrings;
static STRLIST secret_keyrings;
static keyid_list_t unknown_keyids;
static user_id_db_t user_id_db;
static pkc_cache_entry_t pkc_cache;
static int pkc_cache_entries; /* number of entries in pkc cache */
static int scan_keyring( PKT_public_cert *pkc, u32 *keyid,
const char *name, const char *filename );
static int scan_secret_keyring( PKT_secret_cert *skc, u32 *keyid,
const char *name, const char *filename);
void
add_keyring( const char *name )
{
STRLIST sl;
int rc;
/* FIXME: check wether this one is available etc */
/* my be we should do this later */
sl = m_alloc( sizeof *sl + strlen(name) );
strcpy(sl->d, name );
sl->next = keyrings;
keyrings = sl;
/* FIXME: We should remove much out of this mpdule and
* combine it with the keyblock stuff from ringedit.c
* For now we will simple add the filename as keyblock resource
*/
rc = add_keyblock_resource( name, 0, 0 );
if( rc )
log_error("keyblock resource '%s': %s\n", name, g10_errstr(rc) );
}
/****************
* Get the name of the keyrings, start with a sequence number of 0.
*/
const char *
get_keyring( int sequence )
{
STRLIST sl;
for(sl = keyrings; sl && sequence; sl = sl->next, sequence-- )
;
return sl? sl->d : NULL;
}
void
add_secret_keyring( const char *name )
{
STRLIST sl;
int rc;
/* FIXME: check wether this one is available etc */
/* my be we should do this later */
sl = m_alloc( sizeof *sl + strlen(name) );
strcpy(sl->d, name );
sl->next = secret_keyrings;
secret_keyrings = sl;
/* FIXME: We should remove much out of this mpdule and
* combine it with the keyblock stuff from ringedit.c
* For now we will simple add the filename as keyblock resource
*/
rc = add_keyblock_resource( name, 0, 1 );
if( rc )
log_error("secret keyblock resource '%s': %s\n", name, g10_errstr(rc) );
}
void
cache_public_cert( PKT_public_cert *pkc )
{
pkc_cache_entry_t ce;
u32 keyid[2];
if( pkc->pubkey_algo == PUBKEY_ALGO_ELGAMAL
|| pkc->pubkey_algo == PUBKEY_ALGO_RSA ) {
keyid_from_pkc( pkc, keyid );
}
else
return; /* don't know how to get the keyid */
for( ce = pkc_cache; ce; ce = ce->next )
if( ce->keyid[0] == keyid[0] && ce->keyid[1] == keyid[1] ) {
if( DBG_CACHE )
log_debug("cache_public_cert: already in cache\n");
return;
}
if( pkc_cache_entries > MAX_PKC_CACHE_ENTRIES ) {
/* FIMXE: use another algorithm to free some cache slots */
if( pkc_cache_entries == MAX_PKC_CACHE_ENTRIES ) {
pkc_cache_entries++;
log_info("too many entries in pkc cache - disabled\n");
}
ce = pkc_cache;
free_public_cert( ce->pkc );
}
else {
pkc_cache_entries++;
ce = m_alloc( sizeof *ce );
ce->next = pkc_cache;
pkc_cache = ce;
}
ce->pkc = copy_public_cert( NULL, pkc );
ce->keyid[0] = keyid[0];
ce->keyid[1] = keyid[1];
}
/****************
* Store the association of keyid and userid
*/
void
cache_user_id( PKT_user_id *uid, u32 *keyid )
{
user_id_db_t r;
for(r=user_id_db; r; r = r->next )
if( r->keyid[0] == keyid[0] && r->keyid[1] == keyid[1] ) {
if( DBG_CACHE )
log_debug("cache_user_id: already in cache\n");
return;
}
r = m_alloc( sizeof *r + uid->len-1 );
r->keyid[0] = keyid[0];
r->keyid[1] = keyid[1];
r->len = uid->len;
memcpy(r->name, uid->name, r->len);
r->next = user_id_db;
user_id_db = r;
}
/****************
* Get a public key and store it into the allocated pkc
* can be called with PKC set to NULL to just read it into some
* internal structures.
*/
int
get_pubkey( PKT_public_cert *pkc, u32 *keyid )
{
keyid_list_t kl;
int internal = 0;
int rc = 0;
pkc_cache_entry_t ce;
STRLIST sl;
/* lets see wether we checked the keyid already */
for( kl = unknown_keyids; kl; kl = kl->next )
if( kl->keyid[0] == keyid[0] && kl->keyid[1] == keyid[1] )
return G10ERR_NO_PUBKEY; /* already checked and not found */
/* 1. Try to get it from our cache */
for( ce = pkc_cache; ce; ce = ce->next )
if( ce->keyid[0] == keyid[0] && ce->keyid[1] == keyid[1] ) {
if( pkc )
copy_public_cert( pkc, ce->pkc );
return 0;
}
/* more init stuff */
if( !pkc ) {
pkc = m_alloc_clear( sizeof *pkc );
internal++;
}
/* 2. Try to get it from the keyrings */
for(sl = keyrings; sl; sl = sl->next )
if( !scan_keyring( pkc, keyid, NULL, sl->d ) )
goto leave;
/* 3. Try to get it from a key server */
/* 4. not found: store it for future reference */
kl = m_alloc( sizeof *kl );
kl->keyid[0] = keyid[0];
kl->keyid[1] = keyid[1];
kl->next = unknown_keyids;
unknown_keyids = kl;
rc = G10ERR_NO_PUBKEY;
leave:
if( !rc )
cache_public_cert( pkc );
if( internal )
m_free(pkc);
return rc;
}
/****************
* Try to get the pubkey by the userid. This functions looks for the
* first pubkey certificate which has the given name in a user_id.
* if pkc has the pubkey algo set, the function will only return
* a pubkey with that algo.
*
* - If the username starts with 8,9,16 or 17 hex-digits (the first one
* must be in the range 0..9), this is considered a keyid; depending
* on the length a short or complete one.
* - If the username starts with 32,33,40 or 41 hex-digits (the first one
* must be in the range 0..9), this is considered a fingerprint.
* (Not yet implemented)
* - If the username starts with a left angle, we assume it is a complete
* email address and look only at this part.
* - If the userid start with an '=' an exact compare is done; this may
* also follow the keyid in which case both parts are matched.
* (Not yet implemented)
*
*/
int
get_pubkey_byname( PKT_public_cert *pkc, const char *name )
{
int internal = 0;
int rc = 0;
STRLIST sl;
const char *s;
u32 keyid[2] = {0}; /* init to avoid compiler warning */
int use_keyid=0;
/* check what kind of name it is */
for(s = name; *s && isspace(*s); s++ )
;
if( isdigit( *s ) ) { /* a keyid */
int i;
char buf[9];
for(i=0; isxdigit(s[i]); i++ )
;
if( s[i] && !isspace(s[i]) ) /* not terminated by EOS or blank*/
rc = G10ERR_INV_USER_ID;
else if( i == 8 || (i == 9 && *s == '0') ) { /* short keyid */
if( i==9 )
s++;
keyid[1] = strtoul( s, NULL, 16 );
use_keyid++;
}
else if( i == 16 || (i == 17 && *s == '0') ) { /* complete keyid */
if( i==17 )
s++;
mem2str(buf, s, 9 );
keyid[0] = strtoul( buf, NULL, 16 );
keyid[1] = strtoul( s+8, NULL, 16 );
return get_pubkey( pkc, keyid );
}
else
rc = G10ERR_INV_USER_ID;
}
else if( *s == '<' ) { /* an email address */
/* for now handled like a substring */
/* a keyserver might use this for quicker access */
}
else if( *s == '=' ) { /* exact search */
rc = G10ERR_INV_USER_ID; /* nox yet implemented */
}
else if( *s == '#' ) { /* use local id */
rc = G10ERR_INV_USER_ID; /* nox yet implemented */
}
else if( *s == '*' ) { /* substring search */
name++;
}
else if( !*s ) /* empty string */
rc = G10ERR_INV_USER_ID;
if( rc )
goto leave;
if( !pkc ) {
pkc = m_alloc_clear( sizeof *pkc );
internal++;
}
/* 2. Try to get it from the keyrings */
for(sl = keyrings; sl; sl = sl->next )
if( use_keyid ) {
if( !scan_keyring( pkc, keyid, name, sl->d ) )
goto leave;
}
else {
if( !scan_keyring( pkc, NULL, name, sl->d ) )
goto leave;
}
/* 3. Try to get it from a key server */
/* 4. not found: store it for future reference */
rc = G10ERR_NO_PUBKEY;
leave:
if( internal )
m_free(pkc);
return rc;
}
/****************
* Get a secret key and store it into skey
*/
int
get_seckey( PKT_secret_cert *skc, u32 *keyid )
{
STRLIST sl;
int rc=0;
for(sl = secret_keyrings; sl; sl = sl->next )
if( !(rc=scan_secret_keyring( skc, keyid, NULL, sl->d )) )
goto found;
/* fixme: look at other places */
goto leave;
found:
/* get the secret key (this may prompt for a passprase to
* unlock the secret key
*/
if( (rc = check_secret_key( skc )) )
goto leave;
leave:
return rc;
}
/****************
* Get a secret key by name and store it into skc
* If NAME is NULL use the default certificate
*/
int
get_seckey_byname( PKT_secret_cert *skc, const char *name, int unprotect )
{
STRLIST sl;
int rc=0;
for(sl = secret_keyrings; sl; sl = sl->next )
if( !(rc=scan_secret_keyring( skc, NULL, name, sl->d ) ) )
goto found;
/* fixme: look at other places */
goto leave;
found:
/* get the secret key (this may prompt for a passprase to
* unlock the secret key
*/
if( unprotect )
if( (rc = check_secret_key( skc )) )
goto leave;
leave:
return rc;
}
/****************
* scan the keyring and look for either the keyid or the name.
* If both, keyid and name are given, look for keyid but use only
* the low word of it (name is only used as a flag to indicate this mode
* of operation).
*/
static int
scan_keyring( PKT_public_cert *pkc, u32 *keyid,
const char *name, const char *filename )
{
int rc=0;
int found = 0;
IOBUF a;
PACKET pkt;
int save_mode;
u32 akeyid[2];
PKT_public_cert *last_pk = NULL;
int shortkeyid;
shortkeyid = keyid && name;
if( shortkeyid )
name = NULL; /* not used anymore */
if( !(a = iobuf_open( filename ) ) ) {
log_debug("scan_keyring: can't open '%s'\n", filename );
return G10ERR_KEYRING_OPEN;
}
if( !DBG_CACHE )
;
else if( shortkeyid )
log_debug("scan_keyring %s for %08lx\n", filename, keyid[1] );
else if( name )
log_debug("scan_keyring %s for '%s'\n", filename, name );
else if( keyid )
log_debug("scan_keyring %s for %08lx %08lx\n", filename,
keyid[0], keyid[1] );
else
log_debug("scan_keyring %s (all)\n", filename );
save_mode = set_packet_list_mode(0);
init_packet(&pkt);
while( (rc=parse_packet(a, &pkt)) != -1 ) {
if( rc )
; /* e.g. unknown packet */
else if( keyid && found && pkt.pkttype == PKT_PUBLIC_CERT ) {
log_error("Hmmm, pubkey without an user id in '%s'\n", filename);
goto leave;
}
else if( keyid && pkt.pkttype == PKT_PUBLIC_CERT ) {
switch( pkt.pkt.public_cert->pubkey_algo ) {
case PUBKEY_ALGO_ELGAMAL:
case PUBKEY_ALGO_RSA:
keyid_from_pkc( pkt.pkt.public_cert, akeyid );
if( (shortkeyid || akeyid[0] == keyid[0])
&& akeyid[1] == keyid[1] ) {
copy_public_cert( pkc, pkt.pkt.public_cert );
found++;
}
break;
default:
log_error("cannot handle pubkey algo %d\n",
pkt.pkt.public_cert->pubkey_algo);
}
}
else if( keyid && found && pkt.pkttype == PKT_USER_ID ) {
cache_user_id( pkt.pkt.user_id, keyid );
goto leave;
}
else if( name && pkt.pkttype == PKT_PUBLIC_CERT ) {
if( last_pk )
free_public_cert(last_pk);
last_pk = pkt.pkt.public_cert;
pkt.pkt.public_cert = NULL;
}
else if( name && pkt.pkttype == PKT_USER_ID ) {
if( memistr( pkt.pkt.user_id->name, pkt.pkt.user_id->len, name )) {
if( !last_pk )
log_error("Ooops: no pubkey for userid '%.*s'\n",
pkt.pkt.user_id->len, pkt.pkt.user_id->name);
else if( pkc->pubkey_algo &&
pkc->pubkey_algo != last_pk->pubkey_algo )
log_info("skipping id '%.*s': want algo %d, found %d\n",
pkt.pkt.user_id->len, pkt.pkt.user_id->name,
pkc->pubkey_algo, last_pk->pubkey_algo );
else {
copy_public_cert( pkc, last_pk );
goto leave;
}
}
}
else if( !keyid && !name && pkt.pkttype == PKT_PUBLIC_CERT ) {
if( last_pk )
free_public_cert(last_pk);
last_pk = pkt.pkt.public_cert;
pkt.pkt.public_cert = NULL;
}
else if( !keyid && !name && pkt.pkttype == PKT_USER_ID ) {
if( !last_pk )
log_error("Ooops: no pubkey for userid '%.*s'\n",
pkt.pkt.user_id->len, pkt.pkt.user_id->name);
else {
if( last_pk->pubkey_algo == PUBKEY_ALGO_ELGAMAL
|| last_pk->pubkey_algo == PUBKEY_ALGO_RSA ) {
keyid_from_pkc( last_pk, akeyid );
cache_user_id( pkt.pkt.user_id, akeyid );
}
cache_public_cert( last_pk );
}
}
free_packet(&pkt);
}
rc = G10ERR_NO_PUBKEY;
leave:
if( last_pk )
free_public_cert(last_pk);
free_packet(&pkt);
iobuf_close(a);
set_packet_list_mode(save_mode);
return rc;
}
/****************
* This is the function to get a secret key. We use an extra function,
* so that we can easily add special handling for secret keyrings
* PKT returns the secret key certificate.
*/
static int
scan_secret_keyring( PKT_secret_cert *skc, u32 *keyid,
const char *name, const char *filename )
{
int rc=0;
int found = 0;
IOBUF a;
PACKET pkt;
int save_mode;
u32 akeyid[2];
PKT_secret_cert *last_pk = NULL;
int get_first;
u32 dummy_keyid[2];
get_first = !keyid && !name;
if( get_first )
keyid = dummy_keyid;
if( !(a = iobuf_open( filename ) ) ) {
log_debug("scan_secret_keyring: can't open '%s'\n", filename );
return G10ERR_KEYRING_OPEN;
}
save_mode = set_packet_list_mode(0);
init_packet(&pkt);
while( (rc=parse_packet(a, &pkt)) != -1 ) {
if( rc )
; /* e.g. unknown packet */
else if( keyid && found && pkt.pkttype == PKT_SECRET_CERT ) {
log_error("Hmmm, seckey without an user id in '%s'\n", filename);
goto leave;
}
else if( keyid && pkt.pkttype == PKT_SECRET_CERT ) {
switch( pkt.pkt.secret_cert->pubkey_algo ) {
case PUBKEY_ALGO_ELGAMAL:
case PUBKEY_ALGO_RSA:
if( get_first ) {
copy_secret_cert( skc, pkt.pkt.secret_cert );
found++;
}
else {
keyid_from_skc( pkt.pkt.secret_cert, akeyid );
if( (akeyid[0] == keyid[0] && akeyid[1] == keyid[1]) ) {
copy_secret_cert( skc, pkt.pkt.secret_cert );
found++;
}
}
break;
default:
log_error("cannot handle pubkey algo %d\n",
pkt.pkt.secret_cert->pubkey_algo);
}
}
else if( keyid && found && pkt.pkttype == PKT_USER_ID ) {
goto leave;
}
else if( name && pkt.pkttype == PKT_SECRET_CERT ) {
if( last_pk )
free_secret_cert(last_pk);
last_pk = pkt.pkt.secret_cert;
pkt.pkt.secret_cert = NULL;
}
else if( name && pkt.pkttype == PKT_USER_ID ) {
if( memistr( pkt.pkt.user_id->name, pkt.pkt.user_id->len, name )) {
if( !last_pk )
log_error("Ooops: no seckey for userid '%.*s'\n",
pkt.pkt.user_id->len, pkt.pkt.user_id->name);
else if( skc->pubkey_algo &&
skc->pubkey_algo != last_pk->pubkey_algo )
log_info("skipping id '%.*s': want algo %d, found %d\n",
pkt.pkt.user_id->len, pkt.pkt.user_id->name,
skc->pubkey_algo, last_pk->pubkey_algo );
else {
copy_secret_cert( skc, last_pk );
goto leave;
}
}
}
else if( !keyid && !name && pkt.pkttype == PKT_SECRET_CERT ) {
if( last_pk )
free_secret_cert(last_pk);
last_pk = pkt.pkt.secret_cert;
pkt.pkt.secret_cert = NULL;
}
else if( !keyid && !name && pkt.pkttype == PKT_USER_ID ) {
if( !last_pk )
log_error("Ooops: no seckey for userid '%.*s'\n",
pkt.pkt.user_id->len, pkt.pkt.user_id->name);
else {
if( last_pk->pubkey_algo == PUBKEY_ALGO_ELGAMAL
|| last_pk->pubkey_algo == PUBKEY_ALGO_RSA ) {
keyid_from_skc( last_pk, akeyid );
cache_user_id( pkt.pkt.user_id, akeyid );
}
}
}
free_packet(&pkt);
}
rc = G10ERR_NO_SECKEY;
leave:
if( last_pk )
free_secret_cert(last_pk);
free_packet(&pkt);
iobuf_close(a);
set_packet_list_mode(save_mode);
return rc;
}
/****************
* Enumerate all secret keys. Caller must use these procedure:
* 1) create a void pointer and initialize it to NULL
* 2) pass this void pointer by reference to this function
* and provide space for the secret key (pass a buffer for skc)
* 3) call this function as long as it does not return -1
* to indicate EOF.
* 4) Always call this function a last time with SKC set to NULL,
* so that can free it's context.
*
* Return
*/
int
enum_secret_keys( void **context, PKT_secret_cert *skc )
{
int rc=0;
PACKET pkt;
int save_mode;
enum_seckey_context_t *c = *context;
if( !c ) { /* make a new context */
c = m_alloc_clear( sizeof *c );
*context = c;
c->sl = secret_keyrings;
}
if( !skc ) { /* free the context */
m_free( c );
*context = NULL;
return 0;
}
if( c->eof )
return -1;
for( ; c->sl; c->sl = c->sl->next ) {
if( !c->iobuf ) {
if( !(c->iobuf = iobuf_open( c->sl->d ) ) ) {
log_error("enum_secret_keys: can't open '%s'\n", c->sl->d );
continue; /* try next file */
}
}
save_mode = set_packet_list_mode(0);
init_packet(&pkt);
while( (rc=parse_packet(c->iobuf, &pkt)) != -1 ) {
if( rc )
; /* e.g. unknown packet */
else if( pkt.pkttype == PKT_SECRET_CERT ) {
copy_secret_cert( skc, pkt.pkt.secret_cert );
set_packet_list_mode(save_mode);
return 0; /* found */
}
free_packet(&pkt);
}
set_packet_list_mode(save_mode);
iobuf_close(c->iobuf); c->iobuf = NULL;
}
c->eof = 1;
return -1;
}
/****************
* Return a string with a printable representation of the user_id.
* this string must be freed by m_free.
*/
char*
get_user_id_string( u32 *keyid )
{
user_id_db_t r;
char *p;
int pass=0;
/* try it two times; second pass reads from keyrings */
do {
for(r=user_id_db; r; r = r->next )
if( r->keyid[0] == keyid[0] && r->keyid[1] == keyid[1] ) {
p = m_alloc( r->len + 10 );
sprintf(p, "%08lX %.*s", keyid[1], r->len, r->name );
return p;
}
} while( ++pass < 2 && !get_pubkey( NULL, keyid ) );
p = m_alloc( 15 );
sprintf(p, "%08lX [?]", keyid[1] );
return p;
}
char*
get_user_id( u32 *keyid, size_t *rn )
{
user_id_db_t r;
char *p;
int pass=0;
/* try it two times; second pass reads from keyrings */
do {
for(r=user_id_db; r; r = r->next )
if( r->keyid[0] == keyid[0] && r->keyid[1] == keyid[1] ) {
p = m_alloc( r->len );
memcpy(p, r->name, r->len );
*rn = r->len;
return p;
}
} while( ++pass < 2 && !get_pubkey( NULL, keyid ) );
p = m_alloc( 19 );
memcpy(p, "[User id not found]", 19 );
*rn = 19;
return p;
}
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