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gnupg/kbx/kbxserver.c
Werner Koch c7293a4d12
kbx: Add first version of STORE command to keyboxd.
* kbx/Makefile.am (keyboxd_CFLAGS): -DKEYBOX_WITH_X509.
(keyboxd_LDADD): Add libksba.
* kbx/kbxserver.c (cmd_store): New.
* kbx/frontend.c (kbxd_store): New.
* kbx/backend-support.c (is_x509_blob): New.
(be_fingerprint_from_blob): New.
* kbx/backend-kbx.c (be_kbx_seek): Add args FPR and FPRLEN.
(be_kbx_insert): New.

Signed-off-by: Werner Koch <wk@gnupg.org>
2019-10-01 20:09:42 +02:00

826 lines
22 KiB
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/* kbxserver.c - Handle Assuan commands send to the keyboxd
* Copyright (C) 2019 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 <assert.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include "keyboxd.h"
#include <assuan.h>
#include "../common/i18n.h"
#include "../common/server-help.h"
#include "../common/userids.h"
#include "../common/asshelp.h"
#include "../common/host2net.h"
#include "frontend.h"
#define PARM_ERROR(t) assuan_set_error (ctx, \
gpg_error (GPG_ERR_ASS_PARAMETER), (t))
#define set_error(e,t) (ctx ? assuan_set_error (ctx, gpg_error (e), (t)) \
/**/: gpg_error (e))
/* Control structure per connection. */
struct server_local_s
{
/* Data used to associate an Assuan context with local server data */
assuan_context_t assuan_ctx;
/* The session id (a counter). */
unsigned int session_id;
/* If this flag is set to true this process will be terminated after
* the end of this session. */
int stopme;
/* If the first both flags are set the assuan logging of data lines
* is suppressed. The count variable is used to show the number of
* non-logged bytes. */
size_t inhibit_data_logging_count;
unsigned int inhibit_data_logging : 1;
unsigned int inhibit_data_logging_now : 1;
/* This flag is set if the last search command was called with --more. */
unsigned int search_expecting_more : 1;
/* This flag is set if the last search command was successful. */
unsigned int search_any_found : 1;
/* The first is the current search description as parsed by the
* cmd_search. If more than one pattern is required, cmd_search
* also allocates and sets multi_search_desc and
* multi_search_desc_len. If a search description has ever been
* allocated the allocated size is stored at
* multi_search_desc_size. */
KEYBOX_SEARCH_DESC search_desc;
KEYBOX_SEARCH_DESC *multi_search_desc;
unsigned int multi_search_desc_size;
unsigned int multi_search_desc_len;
/* If not NULL write output to this stream instead of using D lines. */
estream_t outstream;
};
/* Return the assuan contxt from the local server info in CTRL. */
static assuan_context_t
get_assuan_ctx_from_ctrl (ctrl_t ctrl)
{
if (!ctrl || !ctrl->server_local)
return NULL;
return ctrl->server_local->assuan_ctx;
}
/* If OUTPUT has been used prepare the output FD for use. This needs
* to be called by all functions which will in any way use
* kbxd_write_data_line later. Whether the output goes to the output
* stream is decided by this function. */
static gpg_error_t
prepare_outstream (ctrl_t ctrl)
{
int fd;
log_assert (ctrl && ctrl->server_local);
if (ctrl->server_local->outstream)
return 0; /* Already enabled. */
fd = translate_sys2libc_fd
(assuan_get_output_fd (get_assuan_ctx_from_ctrl (ctrl)), 1);
if (fd == -1)
return 0; /* No Output command active. */
ctrl->server_local->outstream = es_fdopen_nc (fd, "w");
if (!ctrl->server_local->outstream)
return gpg_err_code_from_syserror ();
return 0;
}
/* The usual writen function; here with diagnostic output. */
static gpg_error_t
kbxd_writen (estream_t fp, const void *buffer, size_t length)
{
gpg_error_t err;
size_t nwritten;
if (es_write (fp, buffer, length, &nwritten))
{
err = gpg_error_from_syserror ();
log_error ("error writing OUTPUT: %s\n", gpg_strerror (err));
}
else if (length != nwritten)
{
err = gpg_error (GPG_ERR_EIO);
log_error ("error writing OUTPUT: %s\n", "short write");
}
else
err = 0;
return err;
}
/* A wrapper around assuan_send_data which makes debugging the output
* in verbose mode easier. It also takes CTRL as argument. */
gpg_error_t
kbxd_write_data_line (ctrl_t ctrl, const void *buffer_arg, size_t size)
{
const char *buffer = buffer_arg;
assuan_context_t ctx = get_assuan_ctx_from_ctrl (ctrl);
gpg_error_t err;
if (!ctx) /* Oops - no assuan context. */
return gpg_error (GPG_ERR_NOT_PROCESSED);
/* Write toa file descriptor if enabled. */
if (ctrl && ctrl->server_local && ctrl->server_local->outstream)
{
unsigned char lenbuf[4];
ulongtobuf (lenbuf, size);
err = kbxd_writen (ctrl->server_local->outstream, lenbuf, 4);
if (!err)
err = kbxd_writen (ctrl->server_local->outstream, buffer, size);
if (!err && es_fflush (ctrl->server_local->outstream))
{
err = gpg_error_from_syserror ();
log_error ("error writing OUTPUT: %s\n", gpg_strerror (err));
}
goto leave;
}
/* If we do not want logging, enable it here. */
if (ctrl && ctrl->server_local && ctrl->server_local->inhibit_data_logging)
ctrl->server_local->inhibit_data_logging_now = 1;
if (0 && opt.verbose && buffer && size)
{
/* Ease reading of output by limiting the line length. */
size_t n, nbytes;
nbytes = size;
do
{
n = nbytes > 64? 64 : nbytes;
err = assuan_send_data (ctx, buffer, n);
if (err)
{
gpg_err_set_errno (EIO);
goto leave;
}
buffer += n;
nbytes -= n;
if (nbytes && (err=assuan_send_data (ctx, NULL, 0))) /* Flush line. */
{
gpg_err_set_errno (EIO);
goto leave;
}
}
while (nbytes);
}
else
{
err = assuan_send_data (ctx, buffer, size);
if (err)
{
gpg_err_set_errno (EIO); /* For use by data_line_cookie_write. */
goto leave;
}
}
leave:
if (ctrl && ctrl->server_local && ctrl->server_local->inhibit_data_logging)
{
ctrl->server_local->inhibit_data_logging_count += size;
ctrl->server_local->inhibit_data_logging_now = 0;
}
return err;
}
/* Helper to print a message while leaving a command. */
static gpg_error_t
leave_cmd (assuan_context_t ctx, gpg_error_t err)
{
if (err && opt.verbose)
{
const char *name = assuan_get_command_name (ctx);
if (!name)
name = "?";
if (gpg_err_source (err) == GPG_ERR_SOURCE_DEFAULT)
log_error ("command '%s' failed: %s\n", name,
gpg_strerror (err));
else
log_error ("command '%s' failed: %s <%s>\n", name,
gpg_strerror (err), gpg_strsource (err));
}
return err;
}
/* Handle OPTION commands. */
static gpg_error_t
option_handler (assuan_context_t ctx, const char *key, const char *value)
{
ctrl_t ctrl = assuan_get_pointer (ctx);
gpg_error_t err = 0;
if (!strcmp (key, "lc-messages"))
{
if (ctrl->lc_messages)
xfree (ctrl->lc_messages);
ctrl->lc_messages = xtrystrdup (value);
if (!ctrl->lc_messages)
return out_of_core ();
}
else
err = gpg_error (GPG_ERR_UNKNOWN_OPTION);
return err;
}
static const char hlp_search[] =
"SEARCH [--no-data] [[--more] PATTERN]\n"
"\n"
"Search for the keys identified by PATTERN. With --more more\n"
"patterns to be used for the search are expected with the next\n"
"command. With --no-data only the search status is returned but\n"
"not the actual data. See also \"NEXT\".";
static gpg_error_t
cmd_search (assuan_context_t ctx, char *line)
{
ctrl_t ctrl = assuan_get_pointer (ctx);
int opt_more, opt_no_data;
gpg_error_t err;
unsigned int n, k;
opt_no_data = has_option (line, "--no-data");
opt_more = has_option (line, "--more");
line = skip_options (line);
ctrl->server_local->search_any_found = 0;
if (!*line)
{
if (opt_more)
{
err = set_error (GPG_ERR_INV_ARG, "--more but no pattern");
goto leave;
}
else if (!*line && ctrl->server_local->search_expecting_more)
{
/* It would be too surprising to first set a pattern but
* finally add no pattern to search the entire DB. */
err = set_error (GPG_ERR_INV_ARG, "--more pending but no pattern");
goto leave;
}
else /* No pattern - return the first item. */
{
memset (&ctrl->server_local->search_desc, 0,
sizeof ctrl->server_local->search_desc);
ctrl->server_local->search_desc.mode = KEYDB_SEARCH_MODE_FIRST;
}
}
else
{
err = classify_user_id (line, &ctrl->server_local->search_desc, 0);
if (err)
goto leave;
}
if (opt_more || ctrl->server_local->search_expecting_more)
{
/* More pattern are expected - store the current one and return
* success. */
if (!ctrl->server_local->multi_search_desc_size)
{
n = 10;
ctrl->server_local->multi_search_desc
= xtrycalloc (n, sizeof *ctrl->server_local->multi_search_desc);
if (!ctrl->server_local->multi_search_desc)
{
err = gpg_error_from_syserror ();
goto leave;
}
ctrl->server_local->multi_search_desc_size = n;
}
if (ctrl->server_local->multi_search_desc_len
== ctrl->server_local->multi_search_desc_size)
{
KEYBOX_SEARCH_DESC *desc;
n = ctrl->server_local->multi_search_desc_size + 10;
desc = xtrycalloc (n, sizeof *desc);
if (!desc)
{
err = gpg_error_from_syserror ();
goto leave;
}
for (k=0; k < ctrl->server_local->multi_search_desc_size; k++)
desc[k] = ctrl->server_local->multi_search_desc[k];
xfree (ctrl->server_local->multi_search_desc);
ctrl->server_local->multi_search_desc = desc;
ctrl->server_local->multi_search_desc_size = n;
}
/* Actually store. */
ctrl->server_local->multi_search_desc
[ctrl->server_local->multi_search_desc_len++]
= ctrl->server_local->search_desc;
if (opt_more)
{
/* We need to be called aagain with more pattern. */
ctrl->server_local->search_expecting_more = 1;
goto leave;
}
ctrl->server_local->search_expecting_more = 0;
/* Continue with the actual search. */
}
else
ctrl->server_local->multi_search_desc_len = 0;
ctrl->server_local->inhibit_data_logging = 1;
ctrl->server_local->inhibit_data_logging_now = 0;
ctrl->server_local->inhibit_data_logging_count = 0;
ctrl->no_data_return = opt_no_data;
err = prepare_outstream (ctrl);
if (err)
;
else if (ctrl->server_local->multi_search_desc_len)
err = kbxd_search (ctrl, ctrl->server_local->multi_search_desc,
ctrl->server_local->multi_search_desc_len, 1);
else
err = kbxd_search (ctrl, &ctrl->server_local->search_desc, 1, 1);
if (err)
goto leave;
/* Set a flag for use by NEXT. */
ctrl->server_local->search_any_found = 1;
leave:
if (err)
ctrl->server_local->multi_search_desc_len = 0;
ctrl->no_data_return = 0;
ctrl->server_local->inhibit_data_logging = 0;
return leave_cmd (ctx, err);
}
static const char hlp_next[] =
"NEXT [--no-data]\n"
"\n"
"Get the next search result from a previus search.";
static gpg_error_t
cmd_next (assuan_context_t ctx, char *line)
{
ctrl_t ctrl = assuan_get_pointer (ctx);
int opt_no_data;
gpg_error_t err;
opt_no_data = has_option (line, "--no-data");
line = skip_options (line);
if (*line)
{
err = set_error (GPG_ERR_INV_ARG, "no args expected");
goto leave;
}
if (!ctrl->server_local->search_any_found)
{
err = set_error (GPG_ERR_NOTHING_FOUND, "no previous SEARCH");
goto leave;
}
ctrl->server_local->inhibit_data_logging = 1;
ctrl->server_local->inhibit_data_logging_now = 0;
ctrl->server_local->inhibit_data_logging_count = 0;
ctrl->no_data_return = opt_no_data;
err = prepare_outstream (ctrl);
if (err)
;
else if (ctrl->server_local->multi_search_desc_len)
{
/* The next condition should never be tru but we better handle
* the first/next transition anyway. */
if (ctrl->server_local->multi_search_desc[0].mode
== KEYDB_SEARCH_MODE_FIRST)
ctrl->server_local->multi_search_desc[0].mode = KEYDB_SEARCH_MODE_NEXT;
err = kbxd_search (ctrl, ctrl->server_local->multi_search_desc,
ctrl->server_local->multi_search_desc_len, 0);
}
else
{
/* We need to do the transition from first to next here. */
if (ctrl->server_local->search_desc.mode == KEYDB_SEARCH_MODE_FIRST)
ctrl->server_local->search_desc.mode = KEYDB_SEARCH_MODE_NEXT;
err = kbxd_search (ctrl, &ctrl->server_local->search_desc, 1, 0);
}
if (err)
goto leave;
leave:
ctrl->no_data_return = 0;
ctrl->server_local->inhibit_data_logging = 0;
return leave_cmd (ctx, err);
}
static const char hlp_store[] =
"STORE [--update]\n"
"\n"
"Insert a key into the database. Whether to insert or update\n"
"the key is decided by looking at the primary key's fingerprint.\n"
"With option --update the key must already exist. The actual key\n"
"material is requested by this function using\n"
" INQUIRE BLOB";
static gpg_error_t
cmd_store (assuan_context_t ctx, char *line)
{
ctrl_t ctrl = assuan_get_pointer (ctx);
int opt_update;
gpg_error_t err;
unsigned char *value = NULL;
size_t valuelen;
opt_update = has_option (line, "--update");
line = skip_options (line);
if (*line)
{
err = set_error (GPG_ERR_INV_ARG, "no args expected");
goto leave;
}
/* Ask for the key material. */
err = assuan_inquire (ctx, "BLOB", &value, &valuelen, 0);
if (err)
{
log_error (_("assuan_inquire failed: %s\n"), gpg_strerror (err));
goto leave;
}
if (!valuelen) /* No data received. */
{
err = gpg_error (GPG_ERR_MISSING_VALUE);
goto leave;
}
err = kbxd_store (ctrl, value, valuelen, opt_update);
leave:
xfree (value);
return leave_cmd (ctx, err);
}
static const char hlp_getinfo[] =
"GETINFO <what>\n"
"\n"
"Multi purpose command to return certain information. \n"
"Supported values of WHAT are:\n"
"\n"
"version - Return the version of the program.\n"
"pid - Return the process id of the server.\n"
"socket_name - Return the name of the socket.\n"
"session_id - Return the current session_id.\n"
"getenv NAME - Return value of envvar NAME\n";
static gpg_error_t
cmd_getinfo (assuan_context_t ctx, char *line)
{
ctrl_t ctrl = assuan_get_pointer (ctx);
gpg_error_t err;
char numbuf[50];
if (!strcmp (line, "version"))
{
const char *s = VERSION;
err = assuan_send_data (ctx, s, strlen (s));
}
else if (!strcmp (line, "pid"))
{
snprintf (numbuf, sizeof numbuf, "%lu", (unsigned long)getpid ());
err = assuan_send_data (ctx, numbuf, strlen (numbuf));
}
else if (!strcmp (line, "socket_name"))
{
const char *s = get_kbxd_socket_name ();
if (!s)
s = "[none]";
err = assuan_send_data (ctx, s, strlen (s));
}
else if (!strcmp (line, "session_id"))
{
snprintf (numbuf, sizeof numbuf, "%u", ctrl->server_local->session_id);
err = assuan_send_data (ctx, numbuf, strlen (numbuf));
}
else if (!strncmp (line, "getenv", 6)
&& (line[6] == ' ' || line[6] == '\t' || !line[6]))
{
line += 6;
while (*line == ' ' || *line == '\t')
line++;
if (!*line)
err = gpg_error (GPG_ERR_MISSING_VALUE);
else
{
const char *s = getenv (line);
if (!s)
err = set_error (GPG_ERR_NOT_FOUND, "No such envvar");
else
err = assuan_send_data (ctx, s, strlen (s));
}
}
else
err = set_error (GPG_ERR_ASS_PARAMETER, "unknown value for WHAT");
return leave_cmd (ctx, err);
}
static const char hlp_killkeyboxd[] =
"KILLKEYBOXD\n"
"\n"
"This command allows a user - given sufficient permissions -\n"
"to kill this keyboxd process.\n";
static gpg_error_t
cmd_killkeyboxd (assuan_context_t ctx, char *line)
{
ctrl_t ctrl = assuan_get_pointer (ctx);
(void)line;
ctrl->server_local->stopme = 1;
assuan_set_flag (ctx, ASSUAN_FORCE_CLOSE, 1);
return gpg_error (GPG_ERR_EOF);
}
static const char hlp_reloadkeyboxd[] =
"RELOADKEYBOXD\n"
"\n"
"This command is an alternative to SIGHUP\n"
"to reload the configuration.";
static gpg_error_t
cmd_reloadkeyboxd (assuan_context_t ctx, char *line)
{
(void)ctx;
(void)line;
kbxd_sighup_action ();
return 0;
}
static const char hlp_output[] =
"OUTPUT FD[=<n>]\n"
"\n"
"Set the file descriptor to write the output data to N. If N is not\n"
"given and the operating system supports file descriptor passing, the\n"
"file descriptor currently in flight will be used.";
/* Tell the assuan library about our commands. */
static int
register_commands (assuan_context_t ctx)
{
static struct {
const char *name;
assuan_handler_t handler;
const char * const help;
} table[] = {
{ "SEARCH", cmd_search, hlp_search },
{ "NEXT", cmd_next, hlp_next },
{ "STORE", cmd_store, hlp_store },
{ "GETINFO", cmd_getinfo, hlp_getinfo },
{ "OUTPUT", NULL, hlp_output },
{ "KILLKEYBOXD",cmd_killkeyboxd,hlp_killkeyboxd },
{ "RELOADKEYBOXD",cmd_reloadkeyboxd,hlp_reloadkeyboxd },
{ NULL, NULL }
};
int i, j, rc;
for (i=j=0; table[i].name; i++)
{
rc = assuan_register_command (ctx, table[i].name, table[i].handler,
table[i].help);
if (rc)
return rc;
}
return 0;
}
/* Note that we do not reset the list of configured keyservers. */
static gpg_error_t
reset_notify (assuan_context_t ctx, char *line)
{
ctrl_t ctrl = assuan_get_pointer (ctx);
(void)line;
(void)ctrl;
return 0;
}
/* This function is called by our assuan log handler to test whether a
* log message shall really be printed. The function must return
* false to inhibit the logging of MSG. CAT gives the requested log
* category. MSG might be NULL. */
int
kbxd_assuan_log_monitor (assuan_context_t ctx, unsigned int cat,
const char *msg)
{
ctrl_t ctrl = assuan_get_pointer (ctx);
(void)cat;
(void)msg;
if (!ctrl || !ctrl->server_local)
return 1; /* Can't decide - allow logging. */
if (!ctrl->server_local->inhibit_data_logging)
return 1; /* Not requested - allow logging. */
/* Disallow logging if *_now is true. */
return !ctrl->server_local->inhibit_data_logging_now;
}
/* Startup the server and run the main command loop. With FD = -1,
* use stdin/stdout. SESSION_ID is either 0 or a unique number
* identifying a session. */
void
kbxd_start_command_handler (ctrl_t ctrl, gnupg_fd_t fd, unsigned int session_id)
{
static const char hello[] = "Keyboxd " VERSION " at your service";
static char *hello_line;
int rc;
assuan_context_t ctx;
ctrl->server_local = xtrycalloc (1, sizeof *ctrl->server_local);
if (!ctrl->server_local)
{
log_error (_("can't allocate control structure: %s\n"),
gpg_strerror (gpg_error_from_syserror ()));
xfree (ctrl);
return;
}
rc = assuan_new (&ctx);
if (rc)
{
log_error (_("failed to allocate assuan context: %s\n"),
gpg_strerror (rc));
kbxd_exit (2);
}
if (fd == GNUPG_INVALID_FD)
{
assuan_fd_t filedes[2];
filedes[0] = assuan_fdopen (0);
filedes[1] = assuan_fdopen (1);
rc = assuan_init_pipe_server (ctx, filedes);
}
else
{
rc = assuan_init_socket_server (ctx, fd,
(ASSUAN_SOCKET_SERVER_ACCEPTED
|ASSUAN_SOCKET_SERVER_FDPASSING));
}
if (rc)
{
assuan_release (ctx);
log_error (_("failed to initialize the server: %s\n"),
gpg_strerror (rc));
kbxd_exit (2);
}
rc = register_commands (ctx);
if (rc)
{
log_error (_("failed to the register commands with Assuan: %s\n"),
gpg_strerror(rc));
kbxd_exit (2);
}
if (!hello_line)
{
hello_line = xtryasprintf
("Home: %s\n"
"Config: %s\n"
"%s",
gnupg_homedir (),
/*opt.config_filename? opt.config_filename :*/ "[none]",
hello);
}
ctrl->server_local->assuan_ctx = ctx;
assuan_set_pointer (ctx, ctrl);
assuan_set_hello_line (ctx, hello_line);
assuan_register_option_handler (ctx, option_handler);
assuan_register_reset_notify (ctx, reset_notify);
ctrl->server_local->session_id = session_id;
/* The next call enable the use of status_printf. */
set_assuan_context_func (get_assuan_ctx_from_ctrl);
for (;;)
{
rc = assuan_accept (ctx);
if (rc == -1)
break;
if (rc)
{
log_info (_("Assuan accept problem: %s\n"), gpg_strerror (rc));
break;
}
#ifndef HAVE_W32_SYSTEM
if (opt.verbose)
{
assuan_peercred_t peercred;
if (!assuan_get_peercred (ctx, &peercred))
log_info ("connection from process %ld (%ld:%ld)\n",
(long)peercred->pid, (long)peercred->uid,
(long)peercred->gid);
}
#endif
rc = assuan_process (ctx);
if (rc)
{
log_info (_("Assuan processing failed: %s\n"), gpg_strerror (rc));
continue;
}
}
assuan_close_output_fd (ctx);
set_assuan_context_func (NULL);
ctrl->server_local->assuan_ctx = NULL;
assuan_release (ctx);
if (ctrl->server_local->stopme)
kbxd_exit (0);
if (ctrl->refcount)
log_error ("oops: connection control structure still referenced (%d)\n",
ctrl->refcount);
else
{
xfree (ctrl->server_local->multi_search_desc);
xfree (ctrl->server_local);
ctrl->server_local = NULL;
}
}