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keyboxd: Restructure client access code.

Browse Source 
* kbx/kbx-client-util.c: New.
* kbx/kbx-client-util.h: New.
* kbx/Makefile.am (client_sources): New.
* g10/keydb.c (parse_keyblock_image): Rename to keydb_parse_keyblock
and make global.
* g10/call-keyboxd.c: Include kbx-client-util.h.
(struct keyboxd_local_s): Remove struct datastream.  Add field kcd.
Remove per_session_init_done.
(lock_datastream, unlock_datastream): Remove.
(prepare_data_pipe, datastream_thread): Remove.
(keydb_get_keyblock_do_parse): Remove.
(gpg_keyboxd_deinit_session_data): Release the KCD object.
(open_context): Use of kbx_client_data_new.
(keydb_get_keyblock): Simplify.
(keydb_search): Use kbx_client_data_cmd and _wait.
--

The data specific part of the code has been moved from gpg to a new
module in kbx/ so that it can also be used by gpgsm.  The OpenPGP
parsing while reading the data has been replaced by storing the data
in memory and parse it later.  That makes a nice interface and
abstracts the fd-passing/D-lines handling away.

Signed-off-by: Werner Koch <wk@gnupg.org>
This commit is contained in:
Werner Koch 2020-09-02 15:05:44 +02:00
parent 4d839f5a80
commit 497db0b5bc
No known key found for this signature in database
GPG Key ID: E3FDFF218E45B72B
6 changed files with 525 additions and 438 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

451
g10/call-keyboxd.c
View File

@ -40,6 +40,7 @@
#include "../common/host2net.h" #include "../common/host2net.h"
#include "../common/exechelp.h" #include "../common/exechelp.h"
#include "../common/status.h" #include "../common/status.h"
#include "../kbx/kbx-client-util.h"
#include "keydb.h" #include "keydb.h"
#include "keydb-private.h" /* For struct keydb_handle_s */ #include "keydb-private.h" /* For struct keydb_handle_s */
@ -57,20 +58,8 @@ struct keyboxd_local_s
/* The active Assuan context. */ /* The active Assuan context. */
assuan_context_t ctx; assuan_context_t ctx;
/* This object is used if fd-passing is used to convey the /* The client data helper context. */
* keyblocks. */ kbx_client_data_t kcd;
struct {
/* NULL or a stream used to receive data. */
estream_t fp;
/* Condition variable to sync the datastream with the command. */
npth_mutex_t mutex;
npth_cond_t cond;
/* The found keyblock or the parsing error. */
kbnode_t found_keyblock;
gpg_error_t found_err;
} datastream;
/* I/O buffer with the last search result or NULL. Used if /* I/O buffer with the last search result or NULL. Used if
* D-lines are used to convey the keyblocks. */ * D-lines are used to convey the keyblocks. */
@ -79,41 +68,14 @@ struct keyboxd_local_s
/* This flag set while an operation is running on this context. */ /* This flag set while an operation is running on this context. */
unsigned int is_active : 1; unsigned int is_active : 1;
/* This flag is set to record that the standard per session init has
* been done. */
unsigned int per_session_init_done : 1;
/* Flag indicating that a search reset is required. */ /* Flag indicating that a search reset is required. */
unsigned int need_search_reset : 1; unsigned int need_search_reset : 1;
}; };
/* Local prototypes. */
static void *datastream_thread (void *arg);
static void
lock_datastream (keyboxd_local_t kbl)
{
int rc = npth_mutex_lock (&kbl->datastream.mutex);
if (rc)
log_fatal ("%s: failed to acquire mutex: %s\n", __func__,
gpg_strerror (gpg_error_from_errno (rc)));
}
static void
unlock_datastream (keyboxd_local_t kbl)
{
int rc = npth_mutex_unlock (&kbl->datastream.mutex);
if (rc)
log_fatal ("%s: failed to release mutex: %s\n", __func__,
gpg_strerror (gpg_error_from_errno (rc)));
}
/* Deinitialize all session resources pertaining to the keyboxd. */ /* Deinitialize all session resources pertaining to the keyboxd. */
void void
gpg_keyboxd_deinit_session_data (ctrl_t ctrl) gpg_keyboxd_deinit_session_data (ctrl_t ctrl)
@ -127,8 +89,8 @@ gpg_keyboxd_deinit_session_data (ctrl_t ctrl)
log_error ("oops: trying to cleanup an active keyboxd context\n"); log_error ("oops: trying to cleanup an active keyboxd context\n");
else else
{ {
es_fclose (kbl->datastream.fp); kbx_client_data_release (kbl->kcd);
kbl->datastream.fp = NULL; kbl->kcd = NULL;
assuan_release (kbl->ctx); assuan_release (kbl->ctx);
kbl->ctx = NULL; kbl->ctx = NULL;
} }
@ -189,73 +151,6 @@ create_new_context (ctrl_t ctrl, assuan_context_t *r_ctx)
/* Setup the pipe used for receiving data from the keyboxd. Store the
* info on KBL. */
static gpg_error_t
prepare_data_pipe (keyboxd_local_t kbl)
{
gpg_error_t err;
int rc;
int inpipe[2];
estream_t infp;
npth_t thread;
npth_attr_t tattr;
err = gnupg_create_inbound_pipe (inpipe, &infp, 0);
if (err)
{
log_error ("error creating inbound pipe: %s\n", gpg_strerror (err));
return err; /* That should not happen. */
}
err = assuan_sendfd (kbl->ctx, INT2FD (inpipe[1]));
if (err)
{
log_error ("sending sending fd %d to keyboxd: %s <%s>\n",
inpipe[1], gpg_strerror (err), gpg_strsource (err));
es_fclose (infp);
close (inpipe[1]);
return 0; /* Server may not support fd-passing. */
}
err = assuan_transact (kbl->ctx, "OUTPUT FD",
NULL, NULL, NULL, NULL, NULL, NULL);
if (err)
{
log_info ("keyboxd does not accept our fd: %s <%s>\n",
gpg_strerror (err), gpg_strsource (err));
es_fclose (infp);
return 0;
}
kbl->datastream.fp = infp;
kbl->datastream.found_keyblock = NULL;
kbl->datastream.found_err = 0;
rc = npth_attr_init (&tattr);
if (rc)
{
err = gpg_error_from_errno (rc);
log_error ("error preparing thread for keyboxd: %s\n",gpg_strerror (err));
es_fclose (infp);
kbl->datastream.fp = NULL;
return err;
}
npth_attr_setdetachstate (&tattr, NPTH_CREATE_DETACHED);
rc = npth_create (&thread, &tattr, datastream_thread, kbl);
if (rc)
{
err = gpg_error_from_errno (rc);
log_error ("error spawning thread for keyboxd: %s\n", gpg_strerror (err));
npth_attr_destroy (&tattr);
es_fclose (infp);
kbl->datastream.fp = NULL;
return err;
}
return 0;
}
/* Get a context for accessing keyboxd. If no context is available a /* Get a context for accessing keyboxd. If no context is available a
* new one is created and if necessary keyboxd is started. R_KBL * new one is created and if necessary keyboxd is started. R_KBL
@ -264,7 +159,6 @@ static gpg_error_t
open_context (ctrl_t ctrl, keyboxd_local_t *r_kbl) open_context (ctrl_t ctrl, keyboxd_local_t *r_kbl)
{ {
gpg_error_t err; gpg_error_t err;
int rc;
keyboxd_local_t kbl; keyboxd_local_t kbl;
*r_kbl = NULL; *r_kbl = NULL;
@ -277,15 +171,6 @@ open_context (ctrl_t ctrl, keyboxd_local_t *r_kbl)
/* Found an inactive keyboxd session - return that. */ /* Found an inactive keyboxd session - return that. */
log_assert (!kbl->is_active); log_assert (!kbl->is_active);
/* But first do the per session init if not yet done. */
if (!kbl->per_session_init_done)
{
err = prepare_data_pipe (kbl);
if (err)
return err;
kbl->per_session_init_done = 1;
}
kbl->is_active = 1; kbl->is_active = 1;
kbl->need_search_reset = 1; kbl->need_search_reset = 1;
@ -298,29 +183,17 @@ open_context (ctrl_t ctrl, keyboxd_local_t *r_kbl)
if (!kbl) if (!kbl)
return gpg_error_from_syserror (); return gpg_error_from_syserror ();
rc = npth_mutex_init (&kbl->datastream.mutex, NULL); err = create_new_context (ctrl, &kbl->ctx);
if (rc) if (err)
{ {
err = gpg_error_from_errno (rc);
log_error ("error initializing mutex: %s\n", gpg_strerror (err));
xfree (kbl);
return err;
}
rc = npth_cond_init (&kbl->datastream.cond, NULL);
if (rc)
{
err = gpg_error_from_errno (rc);
log_error ("error initializing condition: %s\n", gpg_strerror (err));
npth_mutex_destroy (&kbl->datastream.mutex);
xfree (kbl); xfree (kbl);
return err; return err;
} }
err = create_new_context (ctrl, &kbl->ctx); err = kbx_client_data_new (&kbl->kcd, kbl->ctx);
if (err) if (err)
{ {
npth_cond_destroy (&kbl->datastream.cond); assuan_release (kbl->ctx);
npth_mutex_destroy (&kbl->datastream.mutex);
xfree (kbl); xfree (kbl);
return err; return err;
} }
@ -427,224 +300,6 @@ keydb_lock (KEYDB_HANDLE hd)
} }
/* FIXME: This helper is duplicates code of partse_keyblock_image. */
static gpg_error_t
keydb_get_keyblock_do_parse (iobuf_t iobuf, int pk_no, int uid_no,
kbnode_t *r_keyblock)
{
gpg_error_t err;
struct parse_packet_ctx_s parsectx;
PACKET *pkt;
kbnode_t keyblock = NULL;
kbnode_t node, *tail;
int in_cert, save_mode;
int pk_count, uid_count;
*r_keyblock = NULL;
pkt = xtrymalloc (sizeof *pkt);
if (!pkt)
return gpg_error_from_syserror ();
init_packet (pkt);
init_parse_packet (&parsectx, iobuf);
save_mode = set_packet_list_mode (0);
in_cert = 0;
tail = NULL;
pk_count = uid_count = 0;
while ((err = parse_packet (&parsectx, pkt)) != -1)
{
if (gpg_err_code (err) == GPG_ERR_UNKNOWN_PACKET)
{
free_packet (pkt, &parsectx);
init_packet (pkt);
continue;
}
if (err)
{
es_fflush (es_stdout);
log_error ("parse_keyblock_image: read error: %s\n",
gpg_strerror (err));
if (gpg_err_code (err) == GPG_ERR_INV_PACKET)
{
free_packet (pkt, &parsectx);
init_packet (pkt);
continue;
}
err = gpg_error (GPG_ERR_INV_KEYRING);
break;
}
/* Filter allowed packets. */
switch (pkt->pkttype)
{
case PKT_PUBLIC_KEY:
case PKT_PUBLIC_SUBKEY:
case PKT_SECRET_KEY:
case PKT_SECRET_SUBKEY:
case PKT_USER_ID:
case PKT_ATTRIBUTE:
case PKT_SIGNATURE:
case PKT_RING_TRUST:
break; /* Allowed per RFC. */
default:
log_info ("skipped packet of type %d in keybox\n", (int)pkt->pkttype);
free_packet(pkt, &parsectx);
init_packet(pkt);
continue;
}
/* Other sanity checks. */
if (!in_cert && pkt->pkttype != PKT_PUBLIC_KEY)
{
log_error ("parse_keyblock_image: first packet in a keybox blob "
"is not a public key packet\n");
err = gpg_error (GPG_ERR_INV_KEYRING);
break;
}
if (in_cert && (pkt->pkttype == PKT_PUBLIC_KEY
|| pkt->pkttype == PKT_SECRET_KEY))
{
log_error ("parse_keyblock_image: "
"multiple keyblocks in a keybox blob\n");
err = gpg_error (GPG_ERR_INV_KEYRING);
break;
}
in_cert = 1;
node = new_kbnode (pkt);
switch (pkt->pkttype)
{
case PKT_PUBLIC_KEY:
case PKT_PUBLIC_SUBKEY:
case PKT_SECRET_KEY:
case PKT_SECRET_SUBKEY:
if (++pk_count == pk_no)
node->flag |= 1;
break;
case PKT_USER_ID:
if (++uid_count == uid_no)
node->flag |= 2;
break;
default:
break;
}
if (!keyblock)
keyblock = node;
else
*tail = node;
tail = &node->next;
pkt = xtrymalloc (sizeof *pkt);
if (!pkt)
{
err = gpg_error_from_syserror ();
break;
}
init_packet (pkt);
}
set_packet_list_mode (save_mode);
if (err == -1 && keyblock)
err = 0; /* Got the entire keyblock. */
if (err)
release_kbnode (keyblock);
else
{
*r_keyblock = keyblock;
}
free_packet (pkt, &parsectx);
deinit_parse_packet (&parsectx);
xfree (pkt);
return err;
}
/* The thread used to read from the data stream. This is running as
* long as the connection and its datastream exists. */
static void *
datastream_thread (void *arg)
{
keyboxd_local_t kbl = arg;
gpg_error_t err;
int rc;
unsigned char lenbuf[4];
size_t nread, datalen;
iobuf_t iobuf;
int pk_no, uid_no;
kbnode_t keyblock, tmpkeyblock;
log_debug ("Datastream_thread started\n");
while (kbl->datastream.fp)
{
/* log_debug ("Datastream_thread waiting ...\n"); */
if (es_read (kbl->datastream.fp, lenbuf, 4, &nread))
{
err = gpg_error_from_syserror ();
if (gpg_err_code (err) == GPG_ERR_EAGAIN)
continue;
log_error ("error reading data length from keyboxd: %s\n",
gpg_strerror (err));
gnupg_sleep (1);
continue;
}
if (nread != 4)
{
err = gpg_error (GPG_ERR_EIO);
log_error ("error reading data length from keyboxd: %s\n",
"short read");
continue;
}
datalen = buf32_to_size_t (lenbuf);
/* log_debug ("keyboxd announced %zu bytes\n", datalen); */
iobuf = iobuf_esopen (kbl->datastream.fp, "rb", 1, datalen);
pk_no = uid_no = 0; /* FIXME: Get this from the keyboxd. */
err = keydb_get_keyblock_do_parse (iobuf, pk_no, uid_no, &keyblock);
iobuf_close (iobuf);
if (!err)
{
/* log_debug ("parsing datastream succeeded\n"); */
/* Thread-safe assignment to the result var: */
tmpkeyblock = kbl->datastream.found_keyblock;
kbl->datastream.found_keyblock = keyblock;
release_kbnode (tmpkeyblock);
}
else
{
/* log_debug ("parsing datastream failed: %s <%s>\n", */
/* gpg_strerror (err), gpg_strsource (err)); */
tmpkeyblock = kbl->datastream.found_keyblock;
kbl->datastream.found_keyblock = NULL;
kbl->datastream.found_err = err;
release_kbnode (tmpkeyblock);
}
/* Tell the main thread. */
lock_datastream (kbl);
rc = npth_cond_signal (&kbl->datastream.cond);
if (rc)
{
err = gpg_error_from_errno (rc);
log_error ("%s: signaling condition failed: %s\n",
__func__, gpg_strerror (err));
}
unlock_datastream (kbl);
}
log_debug ("Datastream_thread finished\n");
return NULL;
}
/* Return the keyblock last found by keydb_search() in *RET_KB. /* Return the keyblock last found by keydb_search() in *RET_KB.
* *
* On success, the function returns 0 and the caller must free *RET_KB * On success, the function returns 0 and the caller must free *RET_KB
@ -677,19 +332,13 @@ keydb_get_keyblock (KEYDB_HANDLE hd, kbnode_t *ret_kb)
if (hd->kbl->search_result) if (hd->kbl->search_result)
{ {
pk_no = uid_no = 0; /*FIXME: Get this from the keyboxd. */ pk_no = uid_no = 0; /*FIXME: Get this from the keyboxd. */
err = keydb_get_keyblock_do_parse (hd->kbl->search_result, err = keydb_parse_keyblock (hd->kbl->search_result, pk_no, uid_no,
pk_no, uid_no, ret_kb); ret_kb);
/* In contrast to the old code we close the iobuf here and thus /* In contrast to the old code we close the iobuf here and thus
* this function may be called only once to get a keyblock. */ * this function may be called only once to get a keyblock. */
iobuf_close (hd->kbl->search_result); iobuf_close (hd->kbl->search_result);
hd->kbl->search_result = NULL; hd->kbl->search_result = NULL;
} }
else if (hd->kbl->datastream.found_keyblock)
{
*ret_kb = hd->kbl->datastream.found_keyblock;
hd->kbl->datastream.found_keyblock = NULL;
err = 0;
}
else else
{ {
err = gpg_error (GPG_ERR_VALUE_NOT_FOUND); err = gpg_error (GPG_ERR_VALUE_NOT_FOUND);
@ -976,7 +625,8 @@ keydb_search (KEYDB_HANDLE hd, KEYDB_SEARCH_DESC *desc,
gpg_error_t err; gpg_error_t err;
int i; int i;
char line[ASSUAN_LINELENGTH]; char line[ASSUAN_LINELENGTH];
char *buffer;
size_t len;
if (!hd) if (!hd)
return gpg_error (GPG_ERR_INV_ARG); return gpg_error (GPG_ERR_INV_ARG);
@ -989,7 +639,7 @@ keydb_search (KEYDB_HANDLE hd, KEYDB_SEARCH_DESC *desc,
if (DBG_LOOKUP) if (DBG_LOOKUP)
{ {
log_debug ("%s: %zd search descriptions:\n", __func__, ndesc); log_debug ("%s: %zu search descriptions:\n", __func__, ndesc);
for (i = 0; i < ndesc; i ++) for (i = 0; i < ndesc; i ++)
{ {
char *t = keydb_search_desc_dump (&desc[i]); char *t = keydb_search_desc_dump (&desc[i]);
@ -1010,11 +660,6 @@ keydb_search (KEYDB_HANDLE hd, KEYDB_SEARCH_DESC *desc,
iobuf_close (hd->kbl->search_result); iobuf_close (hd->kbl->search_result);
hd->kbl->search_result = NULL; hd->kbl->search_result = NULL;
} }
if (hd->kbl->datastream.found_keyblock)
{
release_kbnode (hd->kbl->datastream.found_keyblock);
hd->kbl->datastream.found_keyblock = NULL;
}
/* Check whether this is a NEXT search. */ /* Check whether this is a NEXT search. */
if (!hd->kbl->need_search_reset) if (!hd->kbl->need_search_reset)
@ -1129,72 +774,14 @@ keydb_search (KEYDB_HANDLE hd, KEYDB_SEARCH_DESC *desc,
do_search: do_search:
hd->last_ubid_valid = 0; hd->last_ubid_valid = 0;
if (hd->kbl->datastream.fp) err = kbx_client_data_cmd (hd->kbl->kcd, line, search_status_cb, hd);
if (!err && !(err = kbx_client_data_wait (hd->kbl->kcd, &buffer, &len)))
{ {
/* log_debug ("Sending command '%s'\n", line); */
err = assuan_transact (hd->kbl->ctx, line,
NULL, NULL,
NULL, NULL,
search_status_cb, hd);
if (err)
{
/* log_debug ("Finished command with error: %s\n", gpg_strerror (err)); */
/* Fixme: On unexpected errors we need a way to cancel the
* data stream. Probably it will be best to close and
* reopen it. */
}
else
{
int rc;
/* log_debug ("Finished command .. telling data stream\n"); */
lock_datastream (hd->kbl);
if (!hd->kbl->datastream.found_keyblock)
{
/* log_debug ("%s: waiting on datastream_cond ...\n", __func__); */
rc = npth_cond_wait (&hd->kbl->datastream.cond,
&hd->kbl->datastream.mutex);
/* log_debug ("%s: waiting on datastream.cond done\n", __func__); */
if (rc)
{
err = gpg_error_from_errno (rc);
log_error ("%s: waiting on condition failed: %s\n",
__func__, gpg_strerror (err));
}
}
unlock_datastream (hd->kbl);
}
}
else /* Slower D-line version if fd-passing was not successful. */
{
membuf_t data;
void *buffer;
size_t len;
init_membuf (&data, 8192);
err = assuan_transact (hd->kbl->ctx, line,
put_membuf_cb, &data,
NULL, NULL,
search_status_cb, hd);
if (err)
{
xfree (get_membuf (&data, &len));
goto leave;
}
buffer = get_membuf (&data, &len);
if (!buffer)
{
err = gpg_error_from_syserror ();
goto leave;
}
hd->kbl->search_result = iobuf_temp_with_content (buffer, len); hd->kbl->search_result = iobuf_temp_with_content (buffer, len);
xfree (buffer); xfree (buffer);
} /* if (hd->last_ubid_valid) */
/* log_printhex (hd->last_ubid, 20, "found UBID:"); */
/* if (hd->last_ubid_valid) */ }
/* log_printhex (hd->last_ubid, 20, "found UBID:"); */
leave: leave:
if (DBG_CLOCK) if (DBG_CLOCK)

4
g10/keydb-private.h
View File

@ -154,6 +154,10 @@ struct keydb_handle_s
/*-- keydb.c --*/ /*-- keydb.c --*/
gpg_error_t keydb_parse_keyblock (iobuf_t iobuf, int pk_no, int uid_no,
kbnode_t *r_keyblock);
/* These are the functions call-keyboxd diverts to if the keyboxd is /* These are the functions call-keyboxd diverts to if the keyboxd is
* not used. */ * not used. */

9
g10/keydb.c
View File

@ -1136,8 +1136,9 @@ keydb_pop_found_state (KEYDB_HANDLE hd)
static gpg_error_t /* Parse the keyblock in IOBUF and return at R_KEYBLOCK. */
parse_keyblock_image (iobuf_t iobuf, int pk_no, int uid_no, gpg_error_t
keydb_parse_keyblock (iobuf_t iobuf, int pk_no, int uid_no,
kbnode_t *r_keyblock) kbnode_t *r_keyblock)
{ {
gpg_error_t err; gpg_error_t err;
@ -1300,7 +1301,7 @@ internal_keydb_get_keyblock (KEYDB_HANDLE hd, KBNODE *ret_kb)
} }
else else
{ {
err = parse_keyblock_image (hd->keyblock_cache.iobuf, err = keydb_parse_keyblock (hd->keyblock_cache.iobuf,
hd->keyblock_cache.pk_no, hd->keyblock_cache.pk_no,
hd->keyblock_cache.uid_no, hd->keyblock_cache.uid_no,
ret_kb); ret_kb);
@ -1332,7 +1333,7 @@ internal_keydb_get_keyblock (KEYDB_HANDLE hd, KBNODE *ret_kb)
&iobuf, &pk_no, &uid_no); &iobuf, &pk_no, &uid_no);
if (!err) if (!err)
{ {
err = parse_keyblock_image (iobuf, pk_no, uid_no, ret_kb); err = keydb_parse_keyblock (iobuf, pk_no, uid_no, ret_kb);
if (!err && hd->keyblock_cache.state == KEYBLOCK_CACHE_PREPARED) if (!err && hd->keyblock_cache.state == KEYBLOCK_CACHE_PREPARED)
{ {
hd->keyblock_cache.state = KEYBLOCK_CACHE_FILLED; hd->keyblock_cache.state = KEYBLOCK_CACHE_FILLED;

8
kbx/Makefile.am
View File

@ -57,9 +57,13 @@ common_sources = \
keybox-openpgp.c \ keybox-openpgp.c \
keybox-dump.c keybox-dump.c
client_sources = \
kbx-client-util.h \
kbx-client-util.c
libkeybox_a_SOURCES = $(common_sources)
libkeybox509_a_SOURCES = $(common_sources) libkeybox_a_SOURCES = $(common_sources) $(client_sources)
libkeybox509_a_SOURCES = $(common_sources) $(client_sources)
libkeybox_a_CFLAGS = $(AM_CFLAGS) libkeybox_a_CFLAGS = $(AM_CFLAGS)
libkeybox509_a_CFLAGS = $(AM_CFLAGS) -DKEYBOX_WITH_X509=1 libkeybox509_a_CFLAGS = $(AM_CFLAGS) -DKEYBOX_WITH_X509=1

450
kbx/kbx-client-util.c Normal file
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@ -0,0 +1,450 @@
/* kbx-client-util.c - Utility functions to implement a keyboxd client
* Copyright (C) 2020 g10 Code GmbH
*
* 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 <https://www.gnu.org/licenses/>.
* SPDX-License-Identifier: GPL-3.0+
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <npth.h>
#include <assuan.h>
#include "../common/util.h"
#include "../common/membuf.h"
#include "../common/i18n.h"
#include "../common/asshelp.h"
#include "../common/exechelp.h"
#include "../common/sysutils.h"
#include "../common/host2net.h"
#include "kbx-client-util.h"
#define MAX_DATABLOB_SIZE (16*1024*1024)
/* This object is used to implement a client to the keyboxd. */
struct kbx_client_data_s
{
/* The used assuan context. */
assuan_context_t ctx;
/* A stream used to receive data. If this is NULL D-lines are used
* to receive the data. */
estream_t fp;
/* Condition variable to sync the datastream with the command. */
npth_mutex_t mutex;
npth_cond_t cond;
/* The data received from the keyboxd and an error code if there was
* a problem (in which case DATA is also set to NULL. This is only
* used if FP is not NULL. */
char *data;
size_t datalen;
gpg_error_t dataerr;
/* Helper variables in case D-lines are used (FP is NULL) */
char *dlinedata;
size_t dlinedatalen;
gpg_error_t dlineerr;
};
static void *datastream_thread (void *arg);
static void
lock_datastream (kbx_client_data_t kcd)
{
int rc = npth_mutex_lock (&kcd->mutex);
if (rc)
log_fatal ("%s: failed to acquire mutex: %s\n", __func__,
gpg_strerror (gpg_error_from_errno (rc)));
}
static void
unlock_datastream (kbx_client_data_t kcd)
{
int rc = npth_mutex_unlock (&kcd->mutex);
if (rc)
log_fatal ("%s: failed to release mutex: %s\n", __func__,
gpg_strerror (gpg_error_from_errno (rc)));
}
/* Setup the pipe used for receiving data from the keyboxd. Store the
* info on KCD. */
static gpg_error_t
prepare_data_pipe (kbx_client_data_t kcd)
{
gpg_error_t err;
int rc;
int inpipe[2];
estream_t infp;
npth_t thread;
npth_attr_t tattr;
kcd->fp = NULL;
kcd->data = NULL;
kcd->datalen = 0;
kcd->dataerr = 0;
err = gnupg_create_inbound_pipe (inpipe, &infp, 0);
if (err)
{
log_error ("error creating inbound pipe: %s\n", gpg_strerror (err));
return err; /* That should not happen. */
}
err = assuan_sendfd (kcd->ctx, INT2FD (inpipe[1]));
if (err)
{
log_error ("sending sending fd %d to keyboxd: %s <%s>\n",
inpipe[1], gpg_strerror (err), gpg_strsource (err));
es_fclose (infp);
gnupg_close_pipe (inpipe[1]);
return 0; /* Server may not support fd-passing. */
}
err = assuan_transact (kcd->ctx, "OUTPUT FD",
NULL, NULL, NULL, NULL, NULL, NULL);
if (err)
{
log_info ("keyboxd does not accept our fd: %s <%s>\n",
gpg_strerror (err), gpg_strsource (err));
es_fclose (infp);
return 0;
}
kcd->fp = infp;
rc = npth_attr_init (&tattr);
if (rc)
{
err = gpg_error_from_errno (rc);
log_error ("error preparing thread for keyboxd: %s\n",gpg_strerror (err));
es_fclose (infp);
kcd->fp = NULL;
return err;
}
npth_attr_setdetachstate (&tattr, NPTH_CREATE_DETACHED);
rc = npth_create (&thread, &tattr, datastream_thread, kcd);
if (rc)
{
err = gpg_error_from_errno (rc);
log_error ("error spawning thread for keyboxd: %s\n", gpg_strerror (err));
npth_attr_destroy (&tattr);
es_fclose (infp);
kcd->fp = NULL;
return err;
}
return 0;
}
/* The thread used to read from the data stream. This is running as
* long as the connection and its datastream exists. */
static void *
datastream_thread (void *arg)
{
kbx_client_data_t kcd = arg;
gpg_error_t err;
int rc;
unsigned char lenbuf[4];
size_t nread, datalen;
int pk_no, uid_no;
char *data, *tmpdata;
/* log_debug ("%s: started\n", __func__); */
while (kcd->fp)
{
/* log_debug ("%s: waiting ...\n", __func__); */
if (es_read (kcd->fp, lenbuf, 4, &nread))
{
err = gpg_error_from_syserror ();
if (gpg_err_code (err) == GPG_ERR_EAGAIN)
continue;
log_error ("error reading data length from keyboxd: %s\n",
gpg_strerror (err));
gnupg_sleep (1);
continue;
}
if (nread != 4)
{
err = gpg_error (GPG_ERR_EIO);
log_error ("error reading data length from keyboxd: %s\n",
"short read");
continue;
}
datalen = buf32_to_size_t (lenbuf);
/* log_debug ("keyboxd announced %zu bytes\n", datalen); */
if (!datalen)
{
log_info ("ignoring empty blob received from keyboxd\n");
continue;
}
if (datalen > MAX_DATABLOB_SIZE)
{
err = gpg_error (GPG_ERR_TOO_LARGE);
/* Drop connection or what shall we do? */
}
else if (!(data = xtrymalloc (datalen+1)))
{
err = gpg_error_from_syserror ();
}
else if (es_read (kcd->fp, data, datalen, &nread))
{
err = gpg_error_from_syserror ();
}
else if (datalen != nread)
{
err = gpg_error (GPG_ERR_TOO_SHORT);
}
else
err = 0;
if (err)
{
log_error ("error reading data from keyboxd: %s <%s>\n",
gpg_strerror (err), gpg_strsource (err));
xfree (data);
data = NULL;
datalen = 0;
}
else
{
/* log_debug ("parsing datastream succeeded\n"); */
pk_no = uid_no = 0; /* FIXME: Get this from the keyboxd. */
}
/* Thread-safe assignment to the result var: */
tmpdata = kcd->data;
kcd->data = data;
kcd->datalen = datalen;
kcd->dataerr = err;
xfree (tmpdata);
data = NULL;
/* Tell the main thread. */
lock_datastream (kcd);
rc = npth_cond_signal (&kcd->cond);
if (rc)
{
err = gpg_error_from_errno (rc);
log_error ("%s: signaling condition failed: %s\n",
__func__, gpg_strerror (err));
}
unlock_datastream (kcd);
}
/* log_debug ("%s: finished\n", __func__); */
return NULL;
}
/* Create a new keyboxd client data object and return it at R_KCD.
* CTX is the assuan context to be used for connecting the
* keyboxd. */
gpg_error_t
kbx_client_data_new (kbx_client_data_t *r_kcd, assuan_context_t ctx)
{
kbx_client_data_t kcd;
int rc;
gpg_error_t err;
kcd = xtrycalloc (1, sizeof *kcd);
if (!kcd)
return gpg_error_from_syserror ();
kcd->ctx = ctx;
rc = npth_mutex_init (&kcd->mutex, NULL);
if (rc)
{
err = gpg_error_from_errno (rc);
log_error ("error initializing mutex: %s\n", gpg_strerror (err));
xfree (kcd);
return err;
}
rc = npth_cond_init (&kcd->cond, NULL);
if (rc)
{
err = gpg_error_from_errno (rc);
log_error ("error initializing condition: %s\n", gpg_strerror (err));
npth_mutex_destroy (&kcd->mutex);
xfree (kcd);
return err;
}
err = prepare_data_pipe (kcd);
if (err)
{
npth_cond_destroy (&kcd->cond);
npth_mutex_destroy (&kcd->mutex);
xfree (kcd);
return err;
}
*r_kcd = kcd;
return 0;
}
void
kbx_client_data_release (kbx_client_data_t kcd)
{
estream_t fp;
if (!kcd)
return;
fp = kcd->fp;
kcd->fp = NULL;
es_fclose (fp); /* That close should let the thread run into an error. */
/* FIXME: Make thread killing explicit. Otherwise we run in a
* log_fatal due to the destroyed mutex. */
npth_cond_destroy (&kcd->cond);
npth_mutex_destroy (&kcd->mutex);
xfree (kcd);
}
/* Send the COMMAND down to the keyboxd associated with KCD.
* STATUS_CB and STATUS_CB_VALUE are the usual status callback as used
* by assuan_transact. After this function has returned success
* kbx_client_data_wait needs to be called to actually return the
* data. */
gpg_error_t
kbx_client_data_cmd (kbx_client_data_t kcd, const char *command,
gpg_error_t (*status_cb)(void *opaque, const char *line),
void *status_cb_value)
{
gpg_error_t err;
xfree (kcd->dlinedata);
kcd->dlinedata = NULL;
kcd->dlinedatalen = 0;
kcd->dlineerr = 0;
if (kcd->fp)
{
/* log_debug ("%s: sending command '%s'\n", __func__, command); */
err = assuan_transact (kcd->ctx, command,
NULL, NULL,
NULL, NULL,
status_cb, status_cb_value);
if (err)
{
if (gpg_err_code (err) != GPG_ERR_NOT_FOUND)
log_debug ("%s: finished command with error: %s\n",
__func__, gpg_strerror (err));
/* Fixme: On unexpected errors we need a way to cancel the
* data stream. Probably it will be best to close and
* reopen it. */
}
}
else /* Slower D-line version if fd-passing is not available. */
{
membuf_t mb;
size_t len;
/* log_debug ("%s: sending command '%s' (no fd-passing)\n", */
/* __func__, command); */
init_membuf (&mb, 8192);
err = assuan_transact (kcd->ctx, command,
put_membuf_cb, &mb,
NULL, NULL,
status_cb, status_cb_value);
if (err)
{
if (gpg_err_code (err) != GPG_ERR_NOT_FOUND)
log_debug ("%s: finished command with error: %s\n",
__func__, gpg_strerror (err));
xfree (get_membuf (&mb, &len));
kcd->dlineerr = err;
goto leave;
}
kcd->dlinedata = get_membuf (&mb, &kcd->dlinedatalen);
if (!kcd->dlinedata)
{
err = gpg_error_from_syserror ();
goto leave;
}
}
leave:
return err;
}
/* Wait for the data from the server and on success return it at
* (R_DATA, R_DATALEN). */
gpg_error_t
kbx_client_data_wait (kbx_client_data_t kcd, char **r_data, size_t *r_datalen)
{
gpg_error_t err = 0;
int rc;
*r_data = NULL;
*r_datalen = 0;
if (kcd->fp)
{
lock_datastream (kcd);
if (!kcd->data && !kcd->dataerr)
{
/* log_debug ("%s: waiting on datastream_cond ...\n", __func__); */
rc = npth_cond_wait (&kcd->cond, &kcd->mutex);
if (rc)
{
err = gpg_error_from_errno (rc);
log_error ("%s: waiting on condition failed: %s\n",
__func__, gpg_strerror (err));
}
/* else */
/* log_debug ("%s: waiting on datastream.cond done\n", __func__); */
}
*r_data = kcd->data;
kcd->data = NULL;
*r_datalen = kcd->datalen;
err = err? err : kcd->dataerr;
unlock_datastream (kcd);
}
else
{
*r_data = kcd->dlinedata;
kcd->dlinedata = NULL;
*r_datalen = kcd->dlinedatalen;
err = kcd->dlineerr;
}
return err;
}

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/* kbx-client-util.c - Defs for utility functions for a keyboxd client
* Copyright (C) 2020 g10 Code GmbH
*
* 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 <https://www.gnu.org/licenses/>.
* SPDX-License-Identifier: GPL-3.0-or-later
*/
#ifndef GNUPG_KBX_CLIENT_UTIL_H
#define GNUPG_KBX_CLIENT_UTIL_H 1
struct kbx_client_data_s;
typedef struct kbx_client_data_s *kbx_client_data_t;
gpg_error_t kbx_client_data_new (kbx_client_data_t *r_kcd,
assuan_context_t ctx);
void kbx_client_data_release (kbx_client_data_t kcd);
gpg_error_t kbx_client_data_cmd (kbx_client_data_t kcd, const char *command,
gpg_error_t (*status_cb)(void *opaque,
const char *line),
void *status_cb_value);
gpg_error_t kbx_client_data_wait (kbx_client_data_t kcd,
char **r_data, size_t *r_datalen);
#endif /*GNUPG_KBX_CLIENT_UTIL_H*/