gnupg/tools/gpg-wks-server.c

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/* gpg-wks-server.c - A server for the Web Key Service protocols.
* Copyright (C) 2016 Werner Koch
*
* 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/>.
*/
/* The Web Key Service I-D defines an update protocol to store a
* public key in the Web Key Directory. The current specification is
* draft-koch-openpgp-webkey-service-01.txt.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include "util.h"
#include "init.h"
#include "sysutils.h"
#include "ccparray.h"
#include "exectool.h"
#include "zb32.h"
#include "mbox-util.h"
#include "name-value.h"
#include "mime-maker.h"
#include "send-mail.h"
#include "gpg-wks.h"
/* The time we wait for a confirmation response. */
#define PENDING_TTL (86400 * 3) /* 3 days. */
/* Constants to identify the commands and options. */
enum cmd_and_opt_values
{
aNull = 0,
oQuiet = 'q',
oVerbose = 'v',
oOutput = 'o',
oDebug = 500,
aReceive,
aCron,
aListDomains,
oGpgProgram,
oSend,
oFrom,
oHeader,
oDummy
};
/* The list of commands and options. */
static ARGPARSE_OPTS opts[] = {
ARGPARSE_group (300, ("@Commands:\n ")),
ARGPARSE_c (aReceive, "receive",
("receive a submission or confirmation")),
ARGPARSE_c (aCron, "cron",
("run regular jobs")),
ARGPARSE_c (aListDomains, "list-domains",
("list configured domains")),
ARGPARSE_group (301, ("@\nOptions:\n ")),
ARGPARSE_s_n (oVerbose, "verbose", ("verbose")),
ARGPARSE_s_n (oQuiet, "quiet", ("be somewhat more quiet")),
ARGPARSE_s_s (oDebug, "debug", "@"),
ARGPARSE_s_s (oGpgProgram, "gpg", "@"),
ARGPARSE_s_n (oSend, "send", "send the mail using sendmail"),
ARGPARSE_s_s (oOutput, "output", "|FILE|write the mail to FILE"),
ARGPARSE_s_s (oFrom, "from", "|ADDR|use ADDR as the default sender"),
ARGPARSE_s_s (oHeader, "header" ,
"|NAME=VALUE|add \"NAME: VALUE\" as header to all mails"),
ARGPARSE_end ()
};
/* The list of supported debug flags. */
static struct debug_flags_s debug_flags [] =
{
{ DBG_CRYPTO_VALUE , "crypto" },
{ DBG_MEMORY_VALUE , "memory" },
{ DBG_MEMSTAT_VALUE, "memstat" },
{ DBG_IPC_VALUE , "ipc" },
{ DBG_EXTPROG_VALUE, "extprog" },
{ 0, NULL }
};
/* State for processing a message. */
struct server_ctx_s
{
char *fpr;
strlist_t mboxes; /* List of addr-specs taken from the UIDs. */
};
typedef struct server_ctx_s *server_ctx_t;
/* Prototypes. */
static gpg_error_t get_domain_list (strlist_t *r_list);
static gpg_error_t command_receive_cb (void *opaque,
const char *mediatype, estream_t fp);
static gpg_error_t command_list_domains (void);
static gpg_error_t command_cron (void);
/* Print usage information and and provide strings for help. */
static const char *
my_strusage( int level )
{
const char *p;
switch (level)
{
case 11: p = "gpg-wks-server (@GNUPG@)";
break;
case 13: p = VERSION; break;
case 17: p = PRINTABLE_OS_NAME; break;
case 19: p = ("Please report bugs to <@EMAIL@>.\n"); break;
case 1:
case 40:
p = ("Usage: gpg-wks-server command [options] (-h for help)");
break;
case 41:
p = ("Syntax: gpg-wks-server command [options]\n"
"Server for the Web Key Service protocol\n");
break;
default: p = NULL; break;
}
return p;
}
static void
wrong_args (const char *text)
{
es_fprintf (es_stderr, "usage: %s [options] %s\n", strusage (11), text);
exit (2);
}
/* Command line parsing. */
static enum cmd_and_opt_values
parse_arguments (ARGPARSE_ARGS *pargs, ARGPARSE_OPTS *popts)
{
enum cmd_and_opt_values cmd = 0;
int no_more_options = 0;
while (!no_more_options && optfile_parse (NULL, NULL, NULL, pargs, popts))
{
switch (pargs->r_opt)
{
case oQuiet: opt.quiet = 1; break;
case oVerbose: opt.verbose++; break;
case oDebug:
if (parse_debug_flag (pargs->r.ret_str, &opt.debug, debug_flags))
{
pargs->r_opt = ARGPARSE_INVALID_ARG;
pargs->err = ARGPARSE_PRINT_ERROR;
}
break;
case oGpgProgram:
opt.gpg_program = pargs->r.ret_str;
break;
case oFrom:
opt.default_from = pargs->r.ret_str;
break;
case oHeader:
append_to_strlist (&opt.extra_headers, pargs->r.ret_str);
break;
case oSend:
opt.use_sendmail = 1;
break;
case oOutput:
opt.output = pargs->r.ret_str;
break;
case aReceive:
case aCron:
case aListDomains:
cmd = pargs->r_opt;
break;
default: pargs->err = 2; break;
}
}
return cmd;
}
/* gpg-wks-server main. */
int
main (int argc, char **argv)
{
gpg_error_t err;
ARGPARSE_ARGS pargs;
enum cmd_and_opt_values cmd;
gnupg_reopen_std ("gpg-wks-server");
set_strusage (my_strusage);
log_set_prefix ("gpg-wks-server", GPGRT_LOG_WITH_PREFIX);
/* Make sure that our subsystems are ready. */
init_common_subsystems (&argc, &argv);
/* Parse the command line. */
pargs.argc = &argc;
pargs.argv = &argv;
pargs.flags = ARGPARSE_FLAG_KEEP;
cmd = parse_arguments (&pargs, opts);
if (log_get_errorcount (0))
exit (2);
/* Print a warning if an argument looks like an option. */
if (!opt.quiet && !(pargs.flags & ARGPARSE_FLAG_STOP_SEEN))
{
int i;
for (i=0; i < argc; i++)
if (argv[i][0] == '-' && argv[i][1] == '-')
log_info (("NOTE: '%s' is not considered an option\n"), argv[i]);
}
/* Set defaults for non given options. */
if (!opt.gpg_program)
opt.gpg_program = gnupg_module_name (GNUPG_MODULE_NAME_GPG);
if (!opt.directory)
opt.directory = "/var/lib/gnupg/wks";
/* Check for syntax errors in the --header option to avoid later
* error messages with a not easy to find cause */
if (opt.extra_headers)
{
strlist_t sl;
for (sl = opt.extra_headers; sl; sl = sl->next)
{
err = mime_maker_add_header (NULL, sl->d, NULL);
if (err)
log_error ("syntax error in \"--header %s\": %s\n",
sl->d, gpg_strerror (err));
}
}
if (log_get_errorcount (0))
exit (2);
/* Check that we have a working directory. */
#if defined(HAVE_STAT)
{
struct stat sb;
if (stat (opt.directory, &sb))
{
err = gpg_error_from_syserror ();
log_error ("error accessing directory '%s': %s\n",
opt.directory, gpg_strerror (err));
exit (2);
}
if (!S_ISDIR(sb.st_mode))
{
log_error ("error accessing directory '%s': %s\n",
opt.directory, "not a directory");
exit (2);
}
if (sb.st_uid != getuid())
{
log_error ("directory '%s' not owned by user\n", opt.directory);
exit (2);
}
if ((sb.st_mode & (S_IROTH|S_IWOTH)))
{
log_error ("directory '%s' has too relaxed permissions\n",
opt.directory);
exit (2);
}
}
#else /*!HAVE_STAT*/
log_fatal ("program build w/o stat() call\n");
#endif /*!HAVE_STAT*/
/* Run the selected command. */
switch (cmd)
{
case aReceive:
if (argc)
wrong_args ("--receive");
err = wks_receive (es_stdin, command_receive_cb, NULL);
break;
case aCron:
if (argc)
wrong_args ("--cron");
err = command_cron ();
break;
case aListDomains:
err = command_list_domains ();
break;
default:
usage (1);
err = gpg_error (GPG_ERR_BUG);
break;
}
if (err)
log_error ("command failed: %s\n", gpg_strerror (err));
return log_get_errorcount (0)? 1:0;
}
static void
list_key_status_cb (void *opaque, const char *keyword, char *args)
{
server_ctx_t ctx = opaque;
(void)ctx;
if (opt.debug)
log_debug ("%s: %s\n", keyword, args);
}
static gpg_error_t
list_key (server_ctx_t ctx, estream_t key)
{
gpg_error_t err;
ccparray_t ccp;
const char **argv;
estream_t listing;
char *line = NULL;
size_t length_of_line = 0;
size_t maxlen;
ssize_t len;
char **fields = NULL;
int nfields;
int lnr;
char *mbox = NULL;
/* We store our results in the context - clear it first. */
xfree (ctx->fpr);
ctx->fpr = NULL;
free_strlist (ctx->mboxes);
ctx->mboxes = NULL;
/* Open a memory stream. */
listing = es_fopenmem (0, "w+b");
if (!listing)
{
err = gpg_error_from_syserror ();
log_error ("error allocating memory buffer: %s\n", gpg_strerror (err));
return err;
}
ccparray_init (&ccp, 0);
ccparray_put (&ccp, "--no-options");
if (!opt.verbose)
ccparray_put (&ccp, "--quiet");
else if (opt.verbose > 1)
ccparray_put (&ccp, "--verbose");
ccparray_put (&ccp, "--batch");
ccparray_put (&ccp, "--status-fd=2");
ccparray_put (&ccp, "--always-trust");
ccparray_put (&ccp, "--with-colons");
ccparray_put (&ccp, "--dry-run");
ccparray_put (&ccp, "--import-options=import-minimal,import-show");
ccparray_put (&ccp, "--import");
ccparray_put (&ccp, NULL);
argv = ccparray_get (&ccp, NULL);
if (!argv)
{
err = gpg_error_from_syserror ();
goto leave;
}
err = gnupg_exec_tool_stream (opt.gpg_program, argv, key,
NULL, listing,
list_key_status_cb, ctx);
if (err)
{
log_error ("import failed: %s\n", gpg_strerror (err));
goto leave;
}
es_rewind (listing);
lnr = 0;
maxlen = 2048; /* Set limit. */
while ((len = es_read_line (listing, &line, &length_of_line, &maxlen)) > 0)
{
lnr++;
if (!maxlen)
{
log_error ("received line too long\n");
err = gpg_error (GPG_ERR_LINE_TOO_LONG);
goto leave;
}
/* Strip newline and carriage return, if present. */
while (len > 0
&& (line[len - 1] == '\n' || line[len - 1] == '\r'))
line[--len] = '\0';
/* log_debug ("line '%s'\n", line); */
xfree (fields);
fields = strtokenize (line, ":");
if (!fields)
{
err = gpg_error_from_syserror ();
log_error ("strtokenize failed: %s\n", gpg_strerror (err));
goto leave;
}
for (nfields = 0; fields[nfields]; nfields++)
;
if (!nfields)
{
err = gpg_error (GPG_ERR_INV_ENGINE);
goto leave;
}
if (!strcmp (fields[0], "sec"))
{
/* gpg may return "sec" as the first record - but we do not
* accept secret keys. */
err = gpg_error (GPG_ERR_NO_PUBKEY);
goto leave;
}
if (lnr == 1 && strcmp (fields[0], "pub"))
{
/* First record is not a public key. */
err = gpg_error (GPG_ERR_INV_ENGINE);
goto leave;
}
if (lnr > 1 && !strcmp (fields[0], "pub"))
{
/* More than one public key. */
err = gpg_error (GPG_ERR_TOO_MANY);
goto leave;
}
if (!strcmp (fields[0], "sub") || !strcmp (fields[0], "ssb"))
break; /* We can stop parsing here. */
if (!strcmp (fields[0], "fpr") && nfields > 9 && !ctx->fpr)
{
ctx->fpr = xtrystrdup (fields[9]);
if (!ctx->fpr)
{
err = gpg_error_from_syserror ();
goto leave;
}
}
else if (!strcmp (fields[0], "uid") && nfields > 9)
{
/* Fixme: Unescape fields[9] */
xfree (mbox);
mbox = mailbox_from_userid (fields[9]);
if (mbox && !append_to_strlist_try (&ctx->mboxes, mbox))
{
err = gpg_error_from_syserror ();
goto leave;
}
}
}
if (len < 0 || es_ferror (listing))
log_error ("error reading memory stream\n");
leave:
xfree (mbox);
xfree (fields);
es_free (line);
xfree (argv);
es_fclose (listing);
return err;
}
/* Take the key in KEYFILE and write it to OUTFILE in binary encoding.
* If ADDRSPEC is given only matching user IDs are included in the
* output. */
static gpg_error_t
copy_key_as_binary (const char *keyfile, const char *outfile,
const char *addrspec)
{
gpg_error_t err;
ccparray_t ccp;
const char **argv;
char *filterexp = NULL;
if (addrspec)
{
filterexp = es_bsprintf ("keep-uid=mbox = %s", addrspec);
if (!filterexp)
{
err = gpg_error_from_syserror ();
log_error ("error allocating memory buffer: %s\n",
gpg_strerror (err));
goto leave;
}
}
ccparray_init (&ccp, 0);
ccparray_put (&ccp, "--no-options");
if (!opt.verbose)
ccparray_put (&ccp, "--quiet");
else if (opt.verbose > 1)
ccparray_put (&ccp, "--verbose");
ccparray_put (&ccp, "--batch");
ccparray_put (&ccp, "--yes");
ccparray_put (&ccp, "--always-trust");
ccparray_put (&ccp, "--no-keyring");
ccparray_put (&ccp, "--output");
ccparray_put (&ccp, outfile);
ccparray_put (&ccp, "--import-options=import-export");
if (filterexp)
{
ccparray_put (&ccp, "--import-filter");
ccparray_put (&ccp, filterexp);
}
ccparray_put (&ccp, "--import");
ccparray_put (&ccp, "--");
ccparray_put (&ccp, keyfile);
ccparray_put (&ccp, NULL);
argv = ccparray_get (&ccp, NULL);
if (!argv)
{
err = gpg_error_from_syserror ();
goto leave;
}
err = gnupg_exec_tool_stream (opt.gpg_program, argv, NULL,
NULL, NULL, NULL, NULL);
if (err)
{
log_error ("%s failed: %s\n", __func__, gpg_strerror (err));
goto leave;
}
leave:
xfree (filterexp);
xfree (argv);
return err;
}
/* Take the key in KEYFILE and write it to DANEFILE using the DANE
* output format. */
static gpg_error_t
copy_key_as_dane (const char *keyfile, const char *danefile)
{
gpg_error_t err;
ccparray_t ccp;
const char **argv;
ccparray_init (&ccp, 0);
ccparray_put (&ccp, "--no-options");
if (!opt.verbose)
ccparray_put (&ccp, "--quiet");
else if (opt.verbose > 1)
ccparray_put (&ccp, "--verbose");
ccparray_put (&ccp, "--batch");
ccparray_put (&ccp, "--yes");
ccparray_put (&ccp, "--always-trust");
ccparray_put (&ccp, "--no-keyring");
ccparray_put (&ccp, "--output");
ccparray_put (&ccp, danefile);
ccparray_put (&ccp, "--export-options=export-dane");
ccparray_put (&ccp, "--import-options=import-export");
ccparray_put (&ccp, "--import");
ccparray_put (&ccp, "--");
ccparray_put (&ccp, keyfile);
ccparray_put (&ccp, NULL);
argv = ccparray_get (&ccp, NULL);
if (!argv)
{
err = gpg_error_from_syserror ();
goto leave;
}
err = gnupg_exec_tool_stream (opt.gpg_program, argv, NULL,
NULL, NULL, NULL, NULL);
if (err)
{
log_error ("%s failed: %s\n", __func__, gpg_strerror (err));
goto leave;
}
leave:
xfree (argv);
return err;
}
static void
encrypt_stream_status_cb (void *opaque, const char *keyword, char *args)
{
(void)opaque;
if (opt.debug)
log_debug ("%s: %s\n", keyword, args);
}
/* Encrypt the INPUT stream to a new stream which is stored at success
* at R_OUTPUT. Encryption is done for the key in file KEYFIL. */
static gpg_error_t
encrypt_stream (estream_t *r_output, estream_t input, const char *keyfile)
{
gpg_error_t err;
ccparray_t ccp;
const char **argv;
estream_t output;
*r_output = NULL;
output = es_fopenmem (0, "w+b");
if (!output)
{
err = gpg_error_from_syserror ();
log_error ("error allocating memory buffer: %s\n", gpg_strerror (err));
return err;
}
ccparray_init (&ccp, 0);
ccparray_put (&ccp, "--no-options");
if (!opt.verbose)
ccparray_put (&ccp, "--quiet");
else if (opt.verbose > 1)
ccparray_put (&ccp, "--verbose");
ccparray_put (&ccp, "--batch");
ccparray_put (&ccp, "--status-fd=2");
ccparray_put (&ccp, "--always-trust");
ccparray_put (&ccp, "--no-keyring");
ccparray_put (&ccp, "--armor");
ccparray_put (&ccp, "--recipient-file");
ccparray_put (&ccp, keyfile);
ccparray_put (&ccp, "--encrypt");
ccparray_put (&ccp, "--");
ccparray_put (&ccp, NULL);
argv = ccparray_get (&ccp, NULL);
if (!argv)
{
err = gpg_error_from_syserror ();
goto leave;
}
err = gnupg_exec_tool_stream (opt.gpg_program, argv, input,
NULL, output,
encrypt_stream_status_cb, NULL);
if (err)
{
log_error ("encryption failed: %s\n", gpg_strerror (err));
goto leave;
}
es_rewind (output);
*r_output = output;
output = NULL;
leave:
es_fclose (output);
xfree (argv);
return err;
}
/* Get the submission address for address MBOX. Caller must free the
* value. If no address can be found NULL is returned. */
static char *
get_submission_address (const char *mbox)
{
gpg_error_t err;
const char *domain;
char *fname, *line, *p;
size_t n;
estream_t fp;
domain = strchr (mbox, '@');
if (!domain)
return NULL;
domain++;
fname = make_filename_try (opt.directory, domain, "submission-address", NULL);
if (!fname)
{
err = gpg_error_from_syserror ();
log_error ("make_filename failed in %s: %s\n",
__func__, gpg_strerror (err));
return NULL;
}
fp = es_fopen (fname, "r");
if (!fp)
{
err = gpg_error_from_syserror ();
if (gpg_err_code (err) == GPG_ERR_ENOENT)
log_info ("Note: no specific submission address configured"
" for domain '%s'\n", domain);
else
log_error ("error reading '%s': %s\n", fname, gpg_strerror (err));
xfree (fname);
return NULL;
}
line = NULL;
n = 0;
if (es_getline (&line, &n, fp) < 0)
{
err = gpg_error_from_syserror ();
log_error ("error reading '%s': %s\n", fname, gpg_strerror (err));
xfree (line);
es_fclose (fp);
xfree (fname);
return NULL;
}
es_fclose (fp);
xfree (fname);
p = strchr (line, '\n');
if (p)
*p = 0;
trim_spaces (line);
if (!is_valid_mailbox (line))
{
log_error ("invalid submission address for domain '%s' detected\n",
domain);
xfree (line);
return NULL;
}
return line;
}
/* Get the policy flags for address MBOX and store them in POLICY. */
static gpg_error_t
get_policy_flags (policy_flags_t policy, const char *mbox)
{
gpg_error_t err;
const char *domain;
char *fname;
estream_t fp;
memset (policy, 0, sizeof *policy);
domain = strchr (mbox, '@');
if (!domain)
return gpg_error (GPG_ERR_INV_USER_ID);
domain++;
fname = make_filename_try (opt.directory, domain, "policy", NULL);
if (!fname)
{
err = gpg_error_from_syserror ();
log_error ("make_filename failed in %s: %s\n",
__func__, gpg_strerror (err));
return err;
}
fp = es_fopen (fname, "r");
if (!fp)
{
err = gpg_error_from_syserror ();
if (gpg_err_code (err) == GPG_ERR_ENOENT)
err = 0;
else
log_error ("error reading '%s': %s\n", fname, gpg_strerror (err));
xfree (fname);
return err;
}
err = wks_parse_policy (policy, fp, 0);
es_fclose (fp);
xfree (fname);
return err;
}
/* We store the key under the name of the nonce we will then send to
* the user. On success the nonce is stored at R_NONCE and the file
* name at R_FNAME. */
static gpg_error_t
store_key_as_pending (const char *dir, estream_t key,
char **r_nonce, char **r_fname)
{
gpg_error_t err;
char *dname = NULL;
char *fname = NULL;
char *nonce = NULL;
estream_t outfp = NULL;
char buffer[1024];
size_t nbytes, nwritten;
*r_nonce = NULL;
*r_fname = NULL;
dname = make_filename_try (dir, "pending", NULL);
if (!dname)
{
err = gpg_error_from_syserror ();
goto leave;
}
/* Create the nonce. We use 20 bytes so that we don't waste a
* character in our zBase-32 encoding. Using the gcrypt's nonce
* function is faster than using the strong random function; this is
* Good Enough for our purpose. */
log_assert (sizeof buffer > 20);
gcry_create_nonce (buffer, 20);
nonce = zb32_encode (buffer, 8 * 20);
memset (buffer, 0, 20); /* Not actually needed but it does not harm. */
if (!nonce)
{
err = gpg_error_from_syserror ();
goto leave;
}
fname = strconcat (dname, "/", nonce, NULL);
if (!fname)
{
err = gpg_error_from_syserror ();
goto leave;
}
/* With 128 bits of random we can expect that no other file exists
* under this name. We use "x" to detect internal errors. */
outfp = es_fopen (fname, "wbx,mode=-rw");
if (!outfp)
{
err = gpg_error_from_syserror ();
log_error ("error creating '%s': %s\n", fname, gpg_strerror (err));
goto leave;
}
es_rewind (key);
for (;;)
{
if (es_read (key, buffer, sizeof buffer, &nbytes))
{
err = gpg_error_from_syserror ();
log_error ("error reading '%s': %s\n",
es_fname_get (key), gpg_strerror (err));
break;
}
if (!nbytes)
{
err = 0;
goto leave; /* Ready. */
}
if (es_write (outfp, buffer, nbytes, &nwritten))
{
err = gpg_error_from_syserror ();
log_error ("error writing '%s': %s\n", fname, gpg_strerror (err));
goto leave;
}
else if (nwritten != nbytes)
{
err = gpg_error (GPG_ERR_EIO);
log_error ("error writing '%s': %s\n", fname, "short write");
goto leave;
}
}
leave:
if (err)
{
es_fclose (outfp);
gnupg_remove (fname);
}
else if (es_fclose (outfp))
{
err = gpg_error_from_syserror ();
log_error ("error closing '%s': %s\n", fname, gpg_strerror (err));
}
if (!err)
{
*r_nonce = nonce;
*r_fname = fname;
}
else
{
xfree (nonce);
xfree (fname);
}
xfree (dname);
return err;
}
/* Send a confirmation request. DIR is the directory used for the
* address MBOX. NONCE is the nonce we want to see in the response to
* this mail. FNAME the name of the file with the key. */
static gpg_error_t
send_confirmation_request (server_ctx_t ctx,
const char *mbox, const char *nonce,
const char *keyfile)
{
gpg_error_t err;
estream_t body = NULL;
estream_t bodyenc = NULL;
mime_maker_t mime = NULL;
char *from_buffer = NULL;
const char *from;
strlist_t sl;
from = from_buffer = get_submission_address (mbox);
if (!from)
{
from = opt.default_from;
if (!from)
{
log_error ("no sender address found for '%s'\n", mbox);
err = gpg_error (GPG_ERR_CONFIGURATION);
goto leave;
}
log_info ("Note: using default sender address '%s'\n", from);
}
body = es_fopenmem (0, "w+b");
if (!body)
{
err = gpg_error_from_syserror ();
log_error ("error allocating memory buffer: %s\n", gpg_strerror (err));
goto leave;
}
/* It is fine to use 8 bit encoding because that is encrypted and
* only our client will see it. */
es_fputs ("Content-Type: application/vnd.gnupg.wks\n"
"Content-Transfer-Encoding: 8bit\n"
"\n",
body);
es_fprintf (body, ("type: confirmation-request\n"
"sender: %s\n"
"address: %s\n"
"fingerprint: %s\n"
"nonce: %s\n"),
from,
mbox,
ctx->fpr,
nonce);
es_rewind (body);
err = encrypt_stream (&bodyenc, body, keyfile);
if (err)
goto leave;
es_fclose (body);
body = NULL;
err = mime_maker_new (&mime, NULL);
if (err)
goto leave;
err = mime_maker_add_header (mime, "From", from);
if (err)
goto leave;
err = mime_maker_add_header (mime, "To", mbox);
if (err)
goto leave;
err = mime_maker_add_header (mime, "Subject", "Confirm your key publication");
if (err)
goto leave;
for (sl = opt.extra_headers; sl; sl = sl->next)
{
err = mime_maker_add_header (mime, sl->d, NULL);
if (err)
goto leave;
}
err = mime_maker_add_header (mime, "Content-Type",
"multipart/encrypted; "
"protocol=\"application/pgp-encrypted\"");
if (err)
goto leave;
err = mime_maker_add_container (mime, "multipart/encrypted");
if (err)
goto leave;
err = mime_maker_add_header (mime, "Content-Type",
"application/pgp-encrypted");
if (err)
goto leave;
err = mime_maker_add_body (mime, "Version: 1\n");
if (err)
goto leave;
err = mime_maker_add_header (mime, "Content-Type",
"application/octet-stream");
if (err)
goto leave;
err = mime_maker_add_stream (mime, &bodyenc);
if (err)
goto leave;
err = wks_send_mime (mime);
leave:
mime_maker_release (mime);
es_fclose (bodyenc);
es_fclose (body);
xfree (from_buffer);
return err;
}
/* Store the key given by KEY into the pending directory and send a
* confirmation requests. */
static gpg_error_t
process_new_key (server_ctx_t ctx, estream_t key)
{
gpg_error_t err;
strlist_t sl;
const char *s;
char *dname = NULL;
char *nonce = NULL;
char *fname = NULL;
struct policy_flags_s policybuf;
/* First figure out the user id from the key. */
err = list_key (ctx, key);
if (err)
goto leave;
if (!ctx->fpr)
{
log_error ("error parsing key (no fingerprint)\n");
err = gpg_error (GPG_ERR_NO_PUBKEY);
goto leave;
}
log_info ("fingerprint: %s\n", ctx->fpr);
for (sl = ctx->mboxes; sl; sl = sl->next)
{
log_info (" addr-spec: %s\n", sl->d);
}
/* Walk over all user ids and send confirmation requests for those
* we support. */
for (sl = ctx->mboxes; sl; sl = sl->next)
{
s = strchr (sl->d, '@');
log_assert (s && s[1]);
xfree (dname);
dname = make_filename_try (opt.directory, s+1, NULL);
if (!dname)
{
err = gpg_error_from_syserror ();
goto leave;
}
if (access (dname, W_OK))
{
log_info ("skipping address '%s': Domain not configured\n", sl->d);
continue;
}
if (get_policy_flags (&policybuf, sl->d))
{
log_info ("skipping address '%s': Bad policy flags\n", sl->d);
continue;
}
if (policybuf.auth_submit)
{
/* Bypass the confirmation stuff and publish the the key as is. */
log_info ("publishing address '%s'\n", sl->d);
/* FIXME: We need to make sure that we do this only for the
* address in the mail. */
log_debug ("auth-submit not yet working!\n");
}
else
{
log_info ("storing address '%s'\n", sl->d);
xfree (nonce);
xfree (fname);
err = store_key_as_pending (dname, key, &nonce, &fname);
if (err)
goto leave;
err = send_confirmation_request (ctx, sl->d, nonce, fname);
if (err)
goto leave;
}
}
leave:
if (nonce)
wipememory (nonce, strlen (nonce));
xfree (nonce);
xfree (fname);
xfree (dname);
return err;
}
/* Send a message to tell the user at MBOX that their key has been
* published. FNAME the name of the file with the key. */
static gpg_error_t
send_congratulation_message (const char *mbox, const char *keyfile)
{
gpg_error_t err;
estream_t body = NULL;
estream_t bodyenc = NULL;
mime_maker_t mime = NULL;
char *from_buffer = NULL;
const char *from;
strlist_t sl;
from = from_buffer = get_submission_address (mbox);
if (!from)
{
from = opt.default_from;
if (!from)
{
log_error ("no sender address found for '%s'\n", mbox);
err = gpg_error (GPG_ERR_CONFIGURATION);
goto leave;
}
log_info ("Note: using default sender address '%s'\n", from);
}
body = es_fopenmem (0, "w+b");
if (!body)
{
err = gpg_error_from_syserror ();
log_error ("error allocating memory buffer: %s\n", gpg_strerror (err));
goto leave;
}
/* It is fine to use 8 bit encoding because that is encrypted and
* only our client will see it. */
es_fputs ("Content-Type: text/plain; charset=utf-8\n"
"Content-Transfer-Encoding: 8bit\n"
"\n",
body);
es_fprintf (body,
"Hello!\n\n"
"The key for your address '%s' has been published\n"
"and can now be retrieved from the Web Key Directory.\n"
"\n"
"For more information on this system see:\n"
"\n"
" https://gnupg.org/faq/wkd.html\n"
"\n"
"Best regards\n"
"\n"
" Gnu Key Publisher\n\n\n"
"-- \n"
"The GnuPG Project welcomes donations: %s\n",
mbox, "https://gnupg.org/donate");
es_rewind (body);
err = encrypt_stream (&bodyenc, body, keyfile);
if (err)
goto leave;
es_fclose (body);
body = NULL;
err = mime_maker_new (&mime, NULL);
if (err)
goto leave;
err = mime_maker_add_header (mime, "From", from);
if (err)
goto leave;
err = mime_maker_add_header (mime, "To", mbox);
if (err)
goto leave;
err = mime_maker_add_header (mime, "Subject", "Your key has been published");
if (err)
goto leave;
for (sl = opt.extra_headers; sl; sl = sl->next)
{
err = mime_maker_add_header (mime, sl->d, NULL);
if (err)
goto leave;
}
err = mime_maker_add_header (mime, "Content-Type",
"multipart/encrypted; "
"protocol=\"application/pgp-encrypted\"");
if (err)
goto leave;
err = mime_maker_add_container (mime, "multipart/encrypted");
if (err)
goto leave;
err = mime_maker_add_header (mime, "Content-Type",
"application/pgp-encrypted");
if (err)
goto leave;
err = mime_maker_add_body (mime, "Version: 1\n");
if (err)
goto leave;
err = mime_maker_add_header (mime, "Content-Type",
"application/octet-stream");
if (err)
goto leave;
err = mime_maker_add_stream (mime, &bodyenc);
if (err)
goto leave;
err = wks_send_mime (mime);
leave:
mime_maker_release (mime);
es_fclose (bodyenc);
es_fclose (body);
xfree (from_buffer);
return err;
}
/* Check that we have send a request with NONCE and publish the key. */
static gpg_error_t
check_and_publish (server_ctx_t ctx, const char *address, const char *nonce)
{
gpg_error_t err;
char *fname = NULL;
char *fnewname = NULL;
estream_t key = NULL;
char *hash = NULL;
const char *domain;
const char *s;
strlist_t sl;
char shaxbuf[32]; /* Used for SHA-1 and SHA-256 */
/* FIXME: There is a bug in name-value.c which adds white space for
* the last pair and thus we strip the nonce here until this has
* been fixed. */
char *nonce2 = xstrdup (nonce);
trim_trailing_spaces (nonce2);
nonce = nonce2;
domain = strchr (address, '@');
log_assert (domain && domain[1]);
domain++;
fname = make_filename_try (opt.directory, domain, "pending", nonce, NULL);
if (!fname)
{
err = gpg_error_from_syserror ();
goto leave;
}
/* Try to open the file with the key. */
key = es_fopen (fname, "rb");
if (!key)
{
err = gpg_error_from_syserror ();
if (gpg_err_code (err) == GPG_ERR_ENOENT)
{
log_info ("no pending request for '%s'\n", address);
err = gpg_error (GPG_ERR_NOT_FOUND);
}
else
log_error ("error reading '%s': %s\n", fname, gpg_strerror (err));
goto leave;
}
/* We need to get the fingerprint from the key. */
err = list_key (ctx, key);
if (err)
goto leave;
if (!ctx->fpr)
{
log_error ("error parsing key (no fingerprint)\n");
err = gpg_error (GPG_ERR_NO_PUBKEY);
goto leave;
}
log_info ("fingerprint: %s\n", ctx->fpr);
for (sl = ctx->mboxes; sl; sl = sl->next)
log_info (" addr-spec: %s\n", sl->d);
/* Check that the key has 'address' as a user id. We use
* case-insensitive matching because the client is expected to
* return the address verbatim. */
for (sl = ctx->mboxes; sl; sl = sl->next)
if (!strcmp (sl->d, address))
break;
if (!sl)
{
log_error ("error publishing key: '%s' is not a user ID of %s\n",
address, ctx->fpr);
err = gpg_error (GPG_ERR_NO_PUBKEY);
goto leave;
}
/* Hash user ID and create filename. */
s = strchr (address, '@');
log_assert (s);
gcry_md_hash_buffer (GCRY_MD_SHA1, shaxbuf, address, s - address);
hash = zb32_encode (shaxbuf, 8*20);
if (!hash)
{
err = gpg_error_from_syserror ();
goto leave;
}
fnewname = make_filename_try (opt.directory, domain, "hu", hash, NULL);
if (!fnewname)
{
err = gpg_error_from_syserror ();
goto leave;
}
/* Publish. */
err = copy_key_as_binary (fname, fnewname, address);
if (err)
{
err = gpg_error_from_syserror ();
log_error ("copying '%s' to '%s' failed: %s\n",
fname, fnewname, gpg_strerror (err));
goto leave;
}
log_info ("key %s published for '%s'\n", ctx->fpr, address);
send_congratulation_message (address, fnewname);
/* Try to publish as DANE record if the DANE directory exists. */
xfree (fname);
fname = fnewname;
fnewname = make_filename_try (opt.directory, domain, "dane", NULL);
if (!fnewname)
{
err = gpg_error_from_syserror ();
goto leave;
}
if (!access (fnewname, W_OK))
{
/* Yes, we have a dane directory. */
s = strchr (address, '@');
log_assert (s);
gcry_md_hash_buffer (GCRY_MD_SHA256, shaxbuf, address, s - address);
xfree (hash);
hash = bin2hex (shaxbuf, 28, NULL);
if (!hash)
{
err = gpg_error_from_syserror ();
goto leave;
}
xfree (fnewname);
fnewname = make_filename_try (opt.directory, domain, "dane", hash, NULL);
if (!fnewname)
{
err = gpg_error_from_syserror ();
goto leave;
}
err = copy_key_as_dane (fname, fnewname);
if (err)
goto leave;
log_info ("key %s published for '%s' (DANE record)\n", ctx->fpr, address);
}
leave:
es_fclose (key);
xfree (hash);
xfree (fnewname);
xfree (fname);
xfree (nonce2);
return err;
}
/* Process a confirmation response in MSG. */
static gpg_error_t
process_confirmation_response (server_ctx_t ctx, estream_t msg)
{
gpg_error_t err;
nvc_t nvc;
nve_t item;
const char *value, *sender, *address, *nonce;
err = nvc_parse (&nvc, NULL, msg);
if (err)
{
log_error ("parsing the WKS message failed: %s\n", gpg_strerror (err));
goto leave;
}
if (opt.debug)
{
log_debug ("response follows:\n");
nvc_write (nvc, log_get_stream ());
}
/* Check that this is a confirmation response. */
if (!((item = nvc_lookup (nvc, "type:")) && (value = nve_value (item))
&& !strcmp (value, "confirmation-response")))
{
if (item && value)
log_error ("received unexpected wks message '%s'\n", value);
else
log_error ("received invalid wks message: %s\n", "'type' missing");
err = gpg_error (GPG_ERR_UNEXPECTED_MSG);
goto leave;
}
/* Get the sender. */
if (!((item = nvc_lookup (nvc, "sender:")) && (value = nve_value (item))
&& is_valid_mailbox (value)))
{
log_error ("received invalid wks message: %s\n",
"'sender' missing or invalid");
err = gpg_error (GPG_ERR_INV_DATA);
goto leave;
}
sender = value;
(void)sender;
/* FIXME: Do we really need the sender?. */
/* Get the address. */
if (!((item = nvc_lookup (nvc, "address:")) && (value = nve_value (item))
&& is_valid_mailbox (value)))
{
log_error ("received invalid wks message: %s\n",
"'address' missing or invalid");
err = gpg_error (GPG_ERR_INV_DATA);
goto leave;
}
address = value;
/* Get the nonce. */
if (!((item = nvc_lookup (nvc, "nonce:")) && (value = nve_value (item))
&& strlen (value) > 16))
{
log_error ("received invalid wks message: %s\n",
"'nonce' missing or too short");
err = gpg_error (GPG_ERR_INV_DATA);
goto leave;
}
nonce = value;
err = check_and_publish (ctx, address, nonce);
leave:
nvc_release (nvc);
return err;
}
/* Called from the MIME receiver to process the plain text data in MSG . */
static gpg_error_t
command_receive_cb (void *opaque, const char *mediatype, estream_t msg)
{
gpg_error_t err;
struct server_ctx_s ctx;
memset (&ctx, 0, sizeof ctx);
(void)opaque;
if (!strcmp (mediatype, "application/pgp-keys"))
err = process_new_key (&ctx, msg);
else if (!strcmp (mediatype, "application/vnd.gnupg.wks"))
err = process_confirmation_response (&ctx, msg);
else
{
log_info ("ignoring unexpected message of type '%s'\n", mediatype);
err = gpg_error (GPG_ERR_UNEXPECTED_MSG);
}
xfree (ctx.fpr);
free_strlist (ctx.mboxes);
return err;
}
/* Return a list of all configured domains. ECh list element is the
* top directory for for the domain. To figure out the actual domain
* name strrchr(name, '/') can be used. */
static gpg_error_t
get_domain_list (strlist_t *r_list)
{
gpg_error_t err;
DIR *dir = NULL;
char *fname = NULL;
struct dirent *dentry;
struct stat sb;
strlist_t list = NULL;
*r_list = NULL;
dir = opendir (opt.directory);
if (!dir)
{
err = gpg_error_from_syserror ();
goto leave;
}
while ((dentry = readdir (dir)))
{
if (*dentry->d_name == '.')
continue;
if (!strchr (dentry->d_name, '.'))
continue; /* No dot - can't be a domain subdir. */
xfree (fname);
fname = make_filename_try (opt.directory, dentry->d_name, NULL);
if (!fname)
{
err = gpg_error_from_syserror ();
log_error ("make_filename failed in %s: %s\n",
__func__, gpg_strerror (err));
goto leave;
}
if (stat (fname, &sb))
{
err = gpg_error_from_syserror ();
log_error ("error accessing '%s': %s\n", fname, gpg_strerror (err));
continue;
}
if (!S_ISDIR(sb.st_mode))
continue;
if (!add_to_strlist_try (&list, fname))
{
err = gpg_error_from_syserror ();
log_error ("add_to_strlist failed in %s: %s\n",
__func__, gpg_strerror (err));
goto leave;
}
}
err = 0;
*r_list = list;
list = NULL;
leave:
free_strlist (list);
if (dir)
closedir (dir);
xfree (fname);
return err;
}
static gpg_error_t
expire_one_domain (const char *top_dirname, const char *domain)
{
gpg_error_t err;
char *dirname;
char *fname = NULL;
DIR *dir = NULL;
struct dirent *dentry;
struct stat sb;
time_t now = gnupg_get_time ();
dirname = make_filename_try (top_dirname, "pending", NULL);
if (!dirname)
{
err = gpg_error_from_syserror ();
log_error ("make_filename failed in %s: %s\n",
__func__, gpg_strerror (err));
goto leave;
}
dir = opendir (dirname);
if (!dir)
{
err = gpg_error_from_syserror ();
log_error (("can't access directory '%s': %s\n"),
dirname, gpg_strerror (err));
goto leave;
}
while ((dentry = readdir (dir)))
{
if (*dentry->d_name == '.')
continue;
xfree (fname);
fname = make_filename_try (dirname, dentry->d_name, NULL);
if (!fname)
{
err = gpg_error_from_syserror ();
log_error ("make_filename failed in %s: %s\n",
__func__, gpg_strerror (err));
goto leave;
}
if (strlen (dentry->d_name) != 32)
{
log_info ("garbage file '%s' ignored\n", fname);
continue;
}
if (stat (fname, &sb))
{
err = gpg_error_from_syserror ();
log_error ("error accessing '%s': %s\n", fname, gpg_strerror (err));
continue;
}
if (S_ISDIR(sb.st_mode))
{
log_info ("garbage directory '%s' ignored\n", fname);
continue;
}
if (sb.st_mtime + PENDING_TTL < now)
{
if (opt.verbose)
log_info ("domain %s: removing pending key '%s'\n",
domain, dentry->d_name);
if (remove (fname))
{
err = gpg_error_from_syserror ();
/* In case the file has just been renamed or another
* processes is cleaning up, we don't print a diagnostic
* for ENOENT. */
if (gpg_err_code (err) != GPG_ERR_ENOENT)
log_error ("error removing '%s': %s\n",
fname, gpg_strerror (err));
}
}
}
err = 0;
leave:
if (dir)
closedir (dir);
xfree (dirname);
xfree (fname);
return err;
}
/* Scan spool directories and expire too old pending keys. */
static gpg_error_t
expire_pending_confirmations (strlist_t domaindirs)
{
gpg_error_t err = 0;
strlist_t sl;
const char *domain;
for (sl = domaindirs; sl; sl = sl->next)
{
domain = strrchr (sl->d, '/');
log_assert (domain);
domain++;
expire_one_domain (sl->d, domain);
}
return err;
}
/* List all configured domains. */
static gpg_error_t
command_list_domains (void)
{
static struct {
const char *name;
const char *perm;
} requireddirs[] = {
{ "pending", "-rwx" },
{ "hu", "-rwxr-xr-x" }
};
gpg_error_t err;
strlist_t domaindirs;
strlist_t sl;
const char *domain;
char *fname = NULL;
int i;
estream_t fp;
err = get_domain_list (&domaindirs);
if (err)
{
log_error ("error reading list of domains: %s\n", gpg_strerror (err));
return err;
}
for (sl = domaindirs; sl; sl = sl->next)
{
domain = strrchr (sl->d, '/');
log_assert (domain);
domain++;
es_printf ("%s\n", domain);
/* Check that the required directories are there. */
for (i=0; i < DIM (requireddirs); i++)
{
xfree (fname);
fname = make_filename_try (sl->d, requireddirs[i].name, NULL);
if (!fname)
{
err = gpg_error_from_syserror ();
goto leave;
}
if (access (fname, W_OK))
{
err = gpg_error_from_syserror ();
if (gpg_err_code (err) == GPG_ERR_ENOENT)
{
if (gnupg_mkdir (fname, requireddirs[i].perm))
{
err = gpg_error_from_syserror ();
log_error ("domain %s: error creating subdir '%s': %s\n",
domain, requireddirs[i].name,
gpg_strerror (err));
}
else
log_info ("domain %s: subdir '%s' created\n",
domain, requireddirs[i].name);
}
else if (err)
log_error ("domain %s: problem with subdir '%s': %s\n",
domain, requireddirs[i].name, gpg_strerror (err));
}
}
/* Print a warning if the submission address is not configured. */
xfree (fname);
fname = make_filename_try (sl->d, "submission-address", NULL);
if (!fname)
{
err = gpg_error_from_syserror ();
goto leave;
}
if (access (fname, F_OK))
{
err = gpg_error_from_syserror ();
if (gpg_err_code (err) == GPG_ERR_ENOENT)
log_error ("domain %s: submission address not configured\n",
domain);
else
log_error ("domain %s: problem with '%s': %s\n",
domain, fname, gpg_strerror (err));
}
/* Check the syntax of the optional policy file. */
xfree (fname);
fname = make_filename_try (sl->d, "policy", NULL);
if (!fname)
{
err = gpg_error_from_syserror ();
goto leave;
}
fp = es_fopen (fname, "r");
if (!fp)
{
err = gpg_error_from_syserror ();
if (gpg_err_code (err) != GPG_ERR_ENOENT)
log_error ("domain %s: error in policy file: %s\n",
domain, gpg_strerror (err));
}
else
{
struct policy_flags_s policy;
err = wks_parse_policy (&policy, fp, 0);
es_fclose (fp);
if (!err)
{
struct policy_flags_s empty_policy;
memset (&empty_policy, 0, sizeof empty_policy);
if (!memcmp (&empty_policy, &policy, sizeof policy))
log_error ("domain %s: empty policy file\n", domain);
}
}
}
err = 0;
leave:
xfree (fname);
free_strlist (domaindirs);
return err;
}
/* Run regular maintenance jobs. */
static gpg_error_t
command_cron (void)
{
gpg_error_t err;
strlist_t domaindirs;
err = get_domain_list (&domaindirs);
if (err)
{
log_error ("error reading list of domains: %s\n", gpg_strerror (err));
return err;
}
err = expire_pending_confirmations (domaindirs);
free_strlist (domaindirs);
return err;
}