/* ks-engine-hkp.c - HKP keyserver engine
* Copyright (C) 2011, 2012 Free Software Foundation, Inc.
* Copyright (C) 2011, 2012, 2014 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 .
*/
#include
#include
#include
#include
#include
#ifdef HAVE_W32_SYSTEM
# ifdef HAVE_WINSOCK2_H
# include
# endif
# include
#else /*!HAVE_W32_SYSTEM*/
# include
# include
# include
#endif /*!HAVE_W32_SYSTEM*/
#include "dirmngr.h"
#include "misc.h"
#include "../common/userids.h"
#include "dns-stuff.h"
#include "ks-engine.h"
/* Substitutes for missing Mingw macro. The EAI_SYSTEM mechanism
seems not to be available (probably because there is only one set
of error codes anyway). For now we use WSAEINVAL. */
#ifndef EAI_OVERFLOW
# define EAI_OVERFLOW EAI_FAIL
#endif
#ifdef HAVE_W32_SYSTEM
# ifndef EAI_SYSTEM
# define EAI_SYSTEM WSAEINVAL
# endif
#endif
/* Number of seconds after a host is marked as resurrected. */
#define RESURRECT_INTERVAL (3600*3) /* 3 hours */
/* To match the behaviour of our old gpgkeys helper code we escape
more characters than actually needed. */
#define EXTRA_ESCAPE_CHARS "@!\"#$%&'()*+,-./:;<=>?[\\]^_{|}~"
/* How many redirections do we allow. */
#define MAX_REDIRECTS 2
/* Number of retries done for a dead host etc. */
#define SEND_REQUEST_RETRIES 3
/* Objects used to maintain information about hosts. */
struct hostinfo_s;
typedef struct hostinfo_s *hostinfo_t;
struct hostinfo_s
{
time_t lastfail; /* Time we tried to connect and failed. */
time_t lastused; /* Time of last use. */
int *pool; /* A -1 terminated array with indices into
HOSTTABLE or NULL if NAME is not a pool
name. */
int poolidx; /* Index into POOL with the used host. -1 if not set. */
unsigned int v4:1; /* Host supports AF_INET. */
unsigned int v6:1; /* Host supports AF_INET6. */
unsigned int onion:1;/* NAME is an onion (Tor HS) address. */
unsigned int dead:1; /* Host is currently unresponsive. */
unsigned int iporname_valid:1; /* The field IPORNAME below is valid */
/* (but may be NULL) */
time_t died_at; /* The time the host was marked dead. If this is
0 the host has been manually marked dead. */
char *cname; /* Canonical name of the host. Only set if this
is a pool or NAME has a numerical IP address. */
char *iporname; /* Numeric IP address or name for printing. */
unsigned short port; /* The port used by the host, 0 if unknown. */
char name[1]; /* The hostname. */
};
/* An array of hostinfo_t for all hosts requested by the caller or
resolved from a pool name and its allocated size.*/
static hostinfo_t *hosttable;
static int hosttable_size;
/* The number of host slots we initially allocate for HOSTTABLE. */
#define INITIAL_HOSTTABLE_SIZE 10
/* Create a new hostinfo object, fill in NAME and put it into
HOSTTABLE. Return the index into hosttable on success or -1 on
error. */
static int
create_new_hostinfo (const char *name)
{
hostinfo_t hi, *newtable;
int newsize;
int idx, rc;
hi = xtrymalloc (sizeof *hi + strlen (name));
if (!hi)
return -1;
strcpy (hi->name, name);
hi->pool = NULL;
hi->poolidx = -1;
hi->lastused = (time_t)(-1);
hi->lastfail = (time_t)(-1);
hi->v4 = 0;
hi->v6 = 0;
hi->onion = 0;
hi->dead = 0;
hi->iporname_valid = 0;
hi->died_at = 0;
hi->cname = NULL;
hi->iporname = NULL;
hi->port = 0;
/* Add it to the hosttable. */
for (idx=0; idx < hosttable_size; idx++)
if (!hosttable[idx])
{
hosttable[idx] = hi;
return idx;
}
/* Need to extend the hosttable. */
newsize = hosttable_size + INITIAL_HOSTTABLE_SIZE;
newtable = xtryrealloc (hosttable, newsize * sizeof *hosttable);
if (!newtable)
{
xfree (hi);
return -1;
}
hosttable = newtable;
idx = hosttable_size;
hosttable_size = newsize;
rc = idx;
hosttable[idx++] = hi;
while (idx < hosttable_size)
hosttable[idx++] = NULL;
return rc;
}
/* Find the host NAME in our table. Return the index into the
hosttable or -1 if not found. */
static int
find_hostinfo (const char *name)
{
int idx;
for (idx=0; idx < hosttable_size; idx++)
if (hosttable[idx] && !ascii_strcasecmp (hosttable[idx]->name, name))
return idx;
return -1;
}
static int
sort_hostpool (const void *xa, const void *xb)
{
int a = *(int *)xa;
int b = *(int *)xb;
assert (a >= 0 && a < hosttable_size);
assert (b >= 0 && b < hosttable_size);
assert (hosttable[a]);
assert (hosttable[b]);
return ascii_strcasecmp (hosttable[a]->name, hosttable[b]->name);
}
/* Return true if the host with the hosttable index TBLIDX is in POOL. */
static int
host_in_pool_p (int *pool, int tblidx)
{
int i, pidx;
for (i=0; (pidx = pool[i]) != -1; i++)
if (pidx == tblidx && hosttable[pidx])
return 1;
return 0;
}
/* Select a random host. Consult TABLE which indices into the global
hosttable. Returns index into TABLE or -1 if no host could be
selected. */
static int
select_random_host (int *table)
{
int *tbl;
size_t tblsize;
int pidx, idx;
/* We create a new table so that we randomly select only from
currently alive hosts. */
for (idx=0, tblsize=0; (pidx = table[idx]) != -1; idx++)
if (hosttable[pidx] && !hosttable[pidx]->dead)
tblsize++;
if (!tblsize)
return -1; /* No hosts. */
tbl = xtrymalloc (tblsize * sizeof *tbl);
if (!tbl)
return -1;
for (idx=0, tblsize=0; (pidx = table[idx]) != -1; idx++)
if (hosttable[pidx] && !hosttable[pidx]->dead)
tbl[tblsize++] = pidx;
if (tblsize == 1) /* Save a get_uint_nonce. */
pidx = tbl[0];
else
pidx = tbl[get_uint_nonce () % tblsize];
xfree (tbl);
return pidx;
}
/* Figure out if a set of DNS records looks like a pool. */
static int
arecords_is_pool (dns_addrinfo_t aibuf)
{
dns_addrinfo_t ai;
int n_v6, n_v4;
n_v6 = n_v4 = 0;
for (ai = aibuf; ai; ai = ai->next)
{
if (ai->family == AF_INET6)
n_v6++;
else if (ai->family == AF_INET)
n_v4++;
}
return n_v6 > 1 || n_v4 > 1;
}
/* Print a warninng iff Tor is not running but Tor has been requested.
* Also return true if it is not running. */
static int
tor_not_running_p (ctrl_t ctrl)
{
assuan_fd_t sock;
if (!dirmngr_use_tor ())
return 0;
sock = assuan_sock_connect_byname (NULL, 0, 0, NULL, ASSUAN_SOCK_TOR);
if (sock != ASSUAN_INVALID_FD)
{
assuan_sock_close (sock);
return 0;
}
log_info ("(it seems Tor is not running)\n");
dirmngr_status (ctrl, "WARNING", "tor_not_running 0",
"Tor is enabled but the local Tor daemon"
" seems to be down", NULL);
return 1;
}
/* Add the host AI under the NAME into the HOSTTABLE. If PORT is not
zero, it specifies which port to use to talk to the host. If NAME
specifies a pool (as indicated by IS_POOL), update the given
reference table accordingly. */
static void
add_host (const char *name, int is_pool,
const dns_addrinfo_t ai, unsigned short port,
int *reftbl, size_t reftblsize, int *refidx)
{
gpg_error_t tmperr;
char *tmphost;
int idx, tmpidx;
int i;
idx = find_hostinfo (name);
if (is_pool)
{
/* For a pool immediately convert the address to a string. */
tmperr = resolve_dns_addr (ai->addr, ai->addrlen,
(DNS_NUMERICHOST | DNS_WITHBRACKET), &tmphost);
}
else if (!is_ip_address (name))
{
/* This is a hostname. Use the name as given without going
* through resolve_dns_addr. */
tmphost = xtrystrdup (name);
if (!tmphost)
tmperr = gpg_error_from_syserror ();
else
tmperr = 0;
}
else
{
/* Do a PTR lookup on AI. If a name was not found the function
* returns the numeric address (with brackets). */
tmperr = resolve_dns_addr (ai->addr, ai->addrlen,
DNS_WITHBRACKET, &tmphost);
}
if (tmperr)
{
log_info ("resolve_dns_addr failed while checking '%s': %s\n",
name, gpg_strerror (tmperr));
}
else if ((*refidx) + 1 >= reftblsize)
{
log_error ("resolve_dns_addr for '%s': '%s'"
" [index table full - ignored]\n", name, tmphost);
}
else
{
if (!is_pool && is_ip_address (name))
/* Update the original entry. */
tmpidx = idx;
else
tmpidx = find_hostinfo (tmphost);
log_info ("resolve_dns_addr for '%s': '%s'%s\n",
name, tmphost,
tmpidx == -1? "" : " [already known]");
if (tmpidx == -1) /* Create a new entry. */
tmpidx = create_new_hostinfo (tmphost);
if (tmpidx == -1)
{
log_error ("map_host for '%s' problem: %s - '%s' [ignored]\n",
name, strerror (errno), tmphost);
}
else /* Set or update the entry. */
{
if (port)
hosttable[tmpidx]->port = port;
if (ai->family == AF_INET6)
{
hosttable[tmpidx]->v6 = 1;
}
else if (ai->family == AF_INET)
{
hosttable[tmpidx]->v4 = 1;
}
else
BUG ();
for (i=0; i < *refidx; i++)
if (reftbl[i] == tmpidx)
break;
if (!(i < *refidx) && tmpidx != idx)
reftbl[(*refidx)++] = tmpidx;
}
}
xfree (tmphost);
}
/* Map the host name NAME to the actual to be used host name. This
* allows us to manage round robin DNS names. We use our own strategy
* to choose one of the hosts. For example we skip those hosts which
* failed for some time and we stick to one host for a time
* independent of DNS retry times. If FORCE_RESELECT is true a new
* host is always selected. If SRVTAG is NULL no service record
* lookup will be done, if it is set that service name is used. The
* selected host is stored as a malloced string at R_HOST; on error
* NULL is stored. If we know the port used by the selected host from
* a service record, a string representation is written to R_PORTSTR,
* otherwise it is left untouched. If R_HTTPFLAGS is not NULL it will
* receive flags which are to be passed to http_open. If R_HTTPHOST
* is not NULL a malloced name of the host is stored there; this might
* be different from R_HOST in case it has been selected from a
* pool. */
static gpg_error_t
map_host (ctrl_t ctrl, const char *name, const char *srvtag, int force_reselect,
char **r_host, char *r_portstr,
unsigned int *r_httpflags, char **r_httphost)
{
gpg_error_t err = 0;
hostinfo_t hi;
int idx;
*r_host = NULL;
if (r_httpflags)
*r_httpflags = 0;
if (r_httphost)
*r_httphost = NULL;
/* No hostname means localhost. */
if (!name || !*name)
{
*r_host = xtrystrdup ("localhost");
return *r_host? 0 : gpg_error_from_syserror ();
}
/* See whether the host is in our table. */
idx = find_hostinfo (name);
if (idx == -1 && is_onion_address (name))
{
idx = create_new_hostinfo (name);
if (idx == -1)
return gpg_error_from_syserror ();
hi = hosttable[idx];
hi->onion = 1;
}
else if (idx == -1)
{
/* We never saw this host. Allocate a new entry. */
dns_addrinfo_t aibuf, ai;
int *reftbl;
size_t reftblsize;
int refidx;
int is_pool = 0;
char *cname;
struct srventry *srvs;
unsigned int srvscount;
reftblsize = 100;
reftbl = xtrymalloc (reftblsize * sizeof *reftbl);
if (!reftbl)
return gpg_error_from_syserror ();
refidx = 0;
idx = create_new_hostinfo (name);
if (idx == -1)
{
err = gpg_error_from_syserror ();
xfree (reftbl);
return err;
}
hi = hosttable[idx];
if (srvtag && !is_ip_address (name))
{
/* Check for SRV records. */
err = get_dns_srv (name, srvtag, NULL, &srvs, &srvscount);
if (err)
{
xfree (reftbl);
if (gpg_err_code (err) == GPG_ERR_ECONNREFUSED)
tor_not_running_p (ctrl);
return err;
}
if (srvscount > 0)
{
int i;
is_pool = srvscount > 1;
for (i = 0; i < srvscount; i++)
{
err = resolve_dns_name (srvs[i].target, 0,
AF_UNSPEC, SOCK_STREAM,
&ai, &cname);
if (err)
continue;
dirmngr_tick (ctrl);
add_host (name, is_pool, ai, srvs[i].port,
reftbl, reftblsize, &refidx);
}
xfree (srvs);
}
}
/* Find all A records for this entry and put them into the pool
list - if any. */
err = resolve_dns_name (name, 0, 0, SOCK_STREAM, &aibuf, &cname);
if (err)
{
log_error ("resolving '%s' failed: %s\n", name, gpg_strerror (err));
err = 0;
}
else
{
/* First figure out whether this is a pool. For a pool we
use a different strategy than for a plain server: We use
the canonical name of the pool as the virtual host along
with the IP addresses. If it is not a pool, we use the
specified name. */
if (! is_pool)
is_pool = arecords_is_pool (aibuf);
if (is_pool && cname)
{
hi->cname = cname;
cname = NULL;
}
for (ai = aibuf; ai; ai = ai->next)
{
if (ai->family != AF_INET && ai->family != AF_INET6)
continue;
if (opt.disable_ipv4 && ai->family == AF_INET)
continue;
dirmngr_tick (ctrl);
add_host (name, is_pool, ai, 0, reftbl, reftblsize, &refidx);
}
}
reftbl[refidx] = -1;
xfree (cname);
free_dns_addrinfo (aibuf);
if (refidx && is_pool)
{
assert (!hi->pool);
hi->pool = xtryrealloc (reftbl, (refidx+1) * sizeof *reftbl);
if (!hi->pool)
{
err = gpg_error_from_syserror ();
log_error ("shrinking index table in map_host failed: %s\n",
gpg_strerror (err));
xfree (reftbl);
return err;
}
qsort (hi->pool, refidx, sizeof *reftbl, sort_hostpool);
}
else
xfree (reftbl);
}
hi = hosttable[idx];
if (hi->pool)
{
/* Deal with the pool name before selecting a host. */
if (r_httphost)
{
*r_httphost = xtrystrdup (hi->cname? hi->cname : hi->name);
if (!*r_httphost)
return gpg_error_from_syserror ();
}
/* If the currently selected host is now marked dead, force a
re-selection . */
if (force_reselect)
hi->poolidx = -1;
else if (hi->poolidx >= 0 && hi->poolidx < hosttable_size
&& hosttable[hi->poolidx] && hosttable[hi->poolidx]->dead)
hi->poolidx = -1;
/* Select a host if needed. */
if (hi->poolidx == -1)
{
hi->poolidx = select_random_host (hi->pool);
if (hi->poolidx == -1)
{
log_error ("no alive host found in pool '%s'\n", name);
if (r_httphost)
{
xfree (*r_httphost);
*r_httphost = NULL;
}
return gpg_error (GPG_ERR_NO_KEYSERVER);
}
}
assert (hi->poolidx >= 0 && hi->poolidx < hosttable_size);
hi = hosttable[hi->poolidx];
assert (hi);
}
else if (r_httphost && is_ip_address (hi->name))
{
/* This is a numerical IP address and not a pool. We want to
* find the canonical name so that it can be used in the HTTP
* Host header. Fixme: We should store that name in the
* hosttable. */
dns_addrinfo_t aibuf, ai;
char *host;
err = resolve_dns_name (hi->name, 0, 0, SOCK_STREAM, &aibuf, NULL);
if (!err)
{
for (ai = aibuf; ai; ai = ai->next)
{
if (ai->family == AF_INET6
|| (!opt.disable_ipv4 && ai->family == AF_INET))
{
err = resolve_dns_addr (ai->addr, ai->addrlen, 0, &host);
if (!err)
{
/* Okay, we return the first found name. */
*r_httphost = host;
break;
}
}
}
}
free_dns_addrinfo (aibuf);
}
if (hi->dead)
{
log_error ("host '%s' marked as dead\n", hi->name);
if (r_httphost)
{
xfree (*r_httphost);
*r_httphost = NULL;
}
return gpg_error (GPG_ERR_NO_KEYSERVER);
}
if (r_httpflags)
{
/* If the hosttable does not indicate that a certain host
supports IPv, we explicit set the corresponding http
flags. The reason for this is that a host might be listed in
a pool as not v6 only but actually support v6 when later
the name is resolved by our http layer. */
if (!hi->v4)
*r_httpflags |= HTTP_FLAG_IGNORE_IPv4;
if (!hi->v6)
*r_httpflags |= HTTP_FLAG_IGNORE_IPv6;
/* Note that we do not set the HTTP_FLAG_FORCE_TOR for onion
addresses because the http module detects this itself. This
also allows us to use an onion address without Tor mode being
enabled. */
}
*r_host = xtrystrdup (hi->name);
if (!*r_host)
{
err = gpg_error_from_syserror ();
if (r_httphost)
{
xfree (*r_httphost);
*r_httphost = NULL;
}
return err;
}
if (hi->port)
snprintf (r_portstr, 6 /* five digits and the sentinel */,
"%hu", hi->port);
return 0;
}
/* Mark the host NAME as dead. NAME may be given as an URL. Returns
true if a host was really marked as dead or was already marked dead
(e.g. by a concurrent session). */
static int
mark_host_dead (const char *name)
{
const char *host;
char *host_buffer = NULL;
parsed_uri_t parsed_uri = NULL;
int done = 0;
if (name && *name && !http_parse_uri (&parsed_uri, name, 1))
{
if (parsed_uri->v6lit)
{
host_buffer = strconcat ("[", parsed_uri->host, "]", NULL);
if (!host_buffer)
log_error ("out of core in mark_host_dead");
host = host_buffer;
}
else
host = parsed_uri->host;
}
else
host = name;
if (host && *host && strcmp (host, "localhost"))
{
hostinfo_t hi;
int idx;
idx = find_hostinfo (host);
if (idx != -1)
{
hi = hosttable[idx];
log_info ("marking host '%s' as dead%s\n",
hi->name, hi->dead? " (again)":"");
hi->dead = 1;
hi->died_at = gnupg_get_time ();
if (!hi->died_at)
hi->died_at = 1;
done = 1;
}
}
http_release_parsed_uri (parsed_uri);
xfree (host_buffer);
return done;
}
/* Mark a host in the hosttable as dead or - if ALIVE is true - as
alive. */
gpg_error_t
ks_hkp_mark_host (ctrl_t ctrl, const char *name, int alive)
{
gpg_error_t err = 0;
hostinfo_t hi, hi2;
int idx, idx2, idx3, n;
if (!name || !*name || !strcmp (name, "localhost"))
return 0;
idx = find_hostinfo (name);
if (idx == -1)
return gpg_error (GPG_ERR_NOT_FOUND);
hi = hosttable[idx];
if (alive && hi->dead)
{
hi->dead = 0;
err = ks_printf_help (ctrl, "marking '%s' as alive", name);
}
else if (!alive && !hi->dead)
{
hi->dead = 1;
hi->died_at = 0; /* Manually set dead. */
err = ks_printf_help (ctrl, "marking '%s' as dead", name);
}
/* If the host is a pool mark all member hosts. */
if (!err && hi->pool)
{
for (idx2=0; !err && (n=hi->pool[idx2]) != -1; idx2++)
{
assert (n >= 0 && n < hosttable_size);
if (!alive)
{
/* Do not mark a host from a pool dead if it is also a
member in another pool. */
for (idx3=0; idx3 < hosttable_size; idx3++)
{
if (hosttable[idx3]
&& hosttable[idx3]->pool
&& idx3 != idx
&& host_in_pool_p (hosttable[idx3]->pool, n))
break;
}
if (idx3 < hosttable_size)
continue; /* Host is also a member of another pool. */
}
hi2 = hosttable[n];
if (!hi2)
;
else if (alive && hi2->dead)
{
hi2->dead = 0;
err = ks_printf_help (ctrl, "marking '%s' as alive",
hi2->name);
}
else if (!alive && !hi2->dead)
{
hi2->dead = 1;
hi2->died_at = 0; /* Manually set dead. */
err = ks_printf_help (ctrl, "marking '%s' as dead",
hi2->name);
}
}
}
return err;
}
/* Debug function to print the entire hosttable. */
gpg_error_t
ks_hkp_print_hosttable (ctrl_t ctrl)
{
gpg_error_t err;
int idx, idx2;
hostinfo_t hi;
membuf_t mb;
time_t curtime;
char *p, *died;
const char *diedstr;
err = ks_print_help (ctrl, "hosttable (idx, ipv6, ipv4, dead, name, time):");
if (err)
return err;
/* FIXME: We need a lock for the hosttable. */
curtime = gnupg_get_time ();
for (idx=0; idx < hosttable_size; idx++)
if ((hi=hosttable[idx]))
{
if (hi->dead && hi->died_at)
{
died = elapsed_time_string (hi->died_at, curtime);
diedstr = died? died : "error";
}
else
diedstr = died = NULL;
if (!hi->iporname_valid)
{
char *canon = NULL;
xfree (hi->iporname);
hi->iporname = NULL;
/* Do a lookup just for the display purpose. */
if (hi->onion || hi->pool)
;
else if (is_ip_address (hi->name))
{
dns_addrinfo_t aibuf, ai;
/* Turn the numerical IP address string into an AI and
* then do a DNS PTR lookup. */
if (!resolve_dns_name (hi->name, 0, 0,
SOCK_STREAM,
&aibuf, &canon))
{
if (canon && is_ip_address (canon))
{
xfree (canon);
canon = NULL;
}
for (ai = aibuf; !canon && ai; ai = ai->next)
{
resolve_dns_addr (ai->addr, ai->addrlen,
DNS_WITHBRACKET, &canon);
if (canon && is_ip_address (canon))
{
/* We already have the numeric IP - no need to
* display it a second time. */
xfree (canon);
canon = NULL;
}
}
}
free_dns_addrinfo (aibuf);
}
else
{
dns_addrinfo_t aibuf, ai;
/* Get the IP address as a string from a name. Note
* that resolve_dns_addr allocates CANON on success
* and thus terminates the loop. */
if (!resolve_dns_name (hi->name, 0,
hi->v6? AF_INET6 : AF_INET,
SOCK_STREAM,
&aibuf, NULL))
{
for (ai = aibuf; !canon && ai; ai = ai->next)
{
resolve_dns_addr (ai->addr, ai->addrlen,
DNS_NUMERICHOST|DNS_WITHBRACKET,
&canon);
}
}
free_dns_addrinfo (aibuf);
}
hi->iporname = canon;
hi->iporname_valid = 1;
}
err = ks_printf_help (ctrl, "%3d %s %s %s %s%s%s%s%s%s%s\n",
idx,
hi->onion? "O" : hi->v6? "6":" ",
hi->v4? "4":" ",
hi->dead? "d":" ",
hi->name,
hi->iporname? " (":"",
hi->iporname? hi->iporname : "",
hi->iporname? ")":"",
diedstr? " (":"",
diedstr? diedstr:"",
diedstr? ")":"" );
xfree (died);
if (err)
return err;
if (hi->cname)
err = ks_printf_help (ctrl, " . %s", hi->cname);
if (err)
return err;
if (hi->pool)
{
init_membuf (&mb, 256);
put_membuf_printf (&mb, " . -->");
for (idx2=0; hi->pool[idx2] != -1; idx2++)
{
put_membuf_printf (&mb, " %d", hi->pool[idx2]);
if (hi->poolidx == hi->pool[idx2])
put_membuf_printf (&mb, "*");
}
put_membuf( &mb, "", 1);
p = get_membuf (&mb, NULL);
if (!p)
return gpg_error_from_syserror ();
err = ks_print_help (ctrl, p);
xfree (p);
if (err)
return err;
}
}
return 0;
}
/* Print a help output for the schemata supported by this module. */
gpg_error_t
ks_hkp_help (ctrl_t ctrl, parsed_uri_t uri)
{
const char data[] =
"Handler for HKP URLs:\n"
" hkp://\n"
#if HTTP_USE_GNUTLS || HTTP_USE_NTBTLS
" hkps://\n"
#endif
"Supported methods: search, get, put\n";
gpg_error_t err;
#if HTTP_USE_GNUTLS || HTTP_USE_NTBTLS
const char data2[] = " hkp\n hkps";
#else
const char data2[] = " hkp";
#endif
if (!uri)
err = ks_print_help (ctrl, data2);
else if (uri->is_http && (!strcmp (uri->scheme, "hkp")
|| !strcmp (uri->scheme, "hkps")))
err = ks_print_help (ctrl, data);
else
err = 0;
return err;
}
/* Build the remote part of the URL from SCHEME, HOST and an optional
* PORT. If NO_SRV is set no SRV record lookup will be done. Returns
* an allocated string at R_HOSTPORT or NULL on failure. If
* R_HTTPHOST is not NULL it receives a malloced string with the
* hostname; this may be different from HOST if HOST is selected from
* a pool. */
static gpg_error_t
make_host_part (ctrl_t ctrl,
const char *scheme, const char *host, unsigned short port,
int force_reselect, int no_srv,
char **r_hostport, unsigned int *r_httpflags, char **r_httphost)
{
gpg_error_t err;
const char *srvtag;
char portstr[10];
char *hostname;
*r_hostport = NULL;
if (!strcmp (scheme, "hkps") || !strcmp (scheme,"https"))
{
scheme = "https";
srvtag = no_srv? NULL : "pgpkey-https";
}
else /* HKP or HTTP. */
{
scheme = "http";
srvtag = no_srv? NULL : "pgpkey-http";
}
portstr[0] = 0;
err = map_host (ctrl, host, srvtag, force_reselect,
&hostname, portstr, r_httpflags, r_httphost);
if (err)
return err;
/* If map_host did not return a port (from a SRV record) but a port
* has been specified (implicitly or explicitly) then use that port.
* In the case that a port was not specified (which is probably a
* bug in https.c) we will set up defaults. */
if (*portstr)
;
else if (!*portstr && port)
snprintf (portstr, sizeof portstr, "%hu", port);
else if (!strcmp (scheme,"https"))
strcpy (portstr, "443");
else
strcpy (portstr, "11371");
if (*hostname != '[' && is_ip_address (hostname) == 6)
*r_hostport = strconcat (scheme, "://[", hostname, "]:", portstr, NULL);
else
*r_hostport = strconcat (scheme, "://", hostname, ":", portstr, NULL);
xfree (hostname);
if (!*r_hostport)
{
if (r_httphost)
{
xfree (*r_httphost);
*r_httphost = NULL;
}
return gpg_error_from_syserror ();
}
return 0;
}
/* Resolve all known keyserver names and update the hosttable. This
is mainly useful for debugging because the resolving is anyway done
on demand. */
gpg_error_t
ks_hkp_resolve (ctrl_t ctrl, parsed_uri_t uri)
{
gpg_error_t err;
char *hostport = NULL;
/* NB: With an explicitly given port we do not want to consult a
* service record because that might be in conflict with the port
* from such a service record. */
err = make_host_part (ctrl, uri->scheme, uri->host, uri->port,
1, uri->explicit_port,
&hostport, NULL, NULL);
if (err)
{
err = ks_printf_help (ctrl, "%s://%s:%hu: resolve failed: %s",
uri->scheme, uri->host, uri->port,
gpg_strerror (err));
}
else
{
err = ks_printf_help (ctrl, "%s", hostport);
xfree (hostport);
}
return err;
}
/* Housekeeping function called from the housekeeping thread. It is
used to mark dead hosts alive so that they may be tried again after
some time. */
void
ks_hkp_housekeeping (time_t curtime)
{
int idx;
hostinfo_t hi;
for (idx=0; idx < hosttable_size; idx++)
{
hi = hosttable[idx];
if (!hi)
continue;
if (!hi->dead)
continue;
if (!hi->died_at)
continue; /* Do not resurrect manually shot hosts. */
if (hi->died_at + RESURRECT_INTERVAL <= curtime
|| hi->died_at > curtime)
{
hi->dead = 0;
log_info ("resurrected host '%s'", hi->name);
}
}
}
/* Reload (SIGHUP) action for this module. We mark all host alive
* even those which have been manually shot. */
void
ks_hkp_reload (void)
{
int idx, count;
hostinfo_t hi;
for (idx=count=0; idx < hosttable_size; idx++)
{
hi = hosttable[idx];
if (!hi)
continue;
hi->iporname_valid = 0;
if (!hi->dead)
continue;
hi->dead = 0;
count++;
}
if (count)
log_info ("number of resurrected hosts: %d", count);
}
/* Send an HTTP request. On success returns an estream object at
R_FP. HOSTPORTSTR is only used for diagnostics. If HTTPHOST is
not NULL it will be used as HTTP "Host" header. If POST_CB is not
NULL a post request is used and that callback is called to allow
writing the post data. If R_HTTP_STATUS is not NULL, the http
status code will be stored there. */
static gpg_error_t
send_request (ctrl_t ctrl, const char *request, const char *hostportstr,
const char *httphost, unsigned int httpflags,
gpg_error_t (*post_cb)(void *, http_t), void *post_cb_value,
estream_t *r_fp, unsigned int *r_http_status)
{
gpg_error_t err;
http_session_t session = NULL;
http_t http = NULL;
int redirects_left = MAX_REDIRECTS;
estream_t fp = NULL;
char *request_buffer = NULL;
*r_fp = NULL;
err = http_session_new (&session, httphost,
((ctrl->http_no_crl? HTTP_FLAG_NO_CRL : 0)
| HTTP_FLAG_TRUST_DEF),
gnupg_http_tls_verify_cb, ctrl);
if (err)
goto leave;
http_session_set_log_cb (session, cert_log_cb);
once_more:
err = http_open (&http,
post_cb? HTTP_REQ_POST : HTTP_REQ_GET,
request,
httphost,
/* fixme: AUTH */ NULL,
(httpflags
|(opt.honor_http_proxy? HTTP_FLAG_TRY_PROXY:0)
|(dirmngr_use_tor ()? HTTP_FLAG_FORCE_TOR:0)
|(opt.disable_ipv4? HTTP_FLAG_IGNORE_IPv4 : 0)),
ctrl->http_proxy,
session,
NULL,
/*FIXME curl->srvtag*/NULL);
if (!err)
{
fp = http_get_write_ptr (http);
/* Avoid caches to get the most recent copy of the key. We set
both the Pragma and Cache-Control versions of the header, so
we're good with both HTTP 1.0 and 1.1. */
es_fputs ("Pragma: no-cache\r\n"
"Cache-Control: no-cache\r\n", fp);
if (post_cb)
err = post_cb (post_cb_value, http);
if (!err)
{
http_start_data (http);
if (es_ferror (fp))
err = gpg_error_from_syserror ();
}
}
if (err)
{
/* Fixme: After a redirection we show the old host name. */
log_error (_("error connecting to '%s': %s\n"),
hostportstr, gpg_strerror (err));
goto leave;
}
/* Wait for the response. */
dirmngr_tick (ctrl);
err = http_wait_response (http);
if (err)
{
log_error (_("error reading HTTP response for '%s': %s\n"),
hostportstr, gpg_strerror (err));
goto leave;
}
if (http_get_tls_info (http, NULL))
{
/* Update the httpflags so that a redirect won't fallback to an
unencrypted connection. */
httpflags |= HTTP_FLAG_FORCE_TLS;
}
if (r_http_status)
*r_http_status = http_get_status_code (http);
switch (http_get_status_code (http))
{
case 200:
err = 0;
break; /* Success. */
case 301:
case 302:
case 307:
{
const char *s = http_get_header (http, "Location");
log_info (_("URL '%s' redirected to '%s' (%u)\n"),
request, s?s:"[none]", http_get_status_code (http));
if (s && *s && redirects_left-- )
{
xfree (request_buffer);
request_buffer = xtrystrdup (s);
if (request_buffer)
{
request = request_buffer;
http_close (http, 0);
http = NULL;
goto once_more;
}
err = gpg_error_from_syserror ();
}
else
err = gpg_error (GPG_ERR_NO_DATA);
log_error (_("too many redirections\n"));
}
goto leave;
case 501:
err = gpg_error (GPG_ERR_NOT_IMPLEMENTED);
goto leave;
default:
log_error (_("error accessing '%s': http status %u\n"),
request, http_get_status_code (http));
err = gpg_error (GPG_ERR_NO_DATA);
goto leave;
}
/* FIXME: We should register a permanent redirection and whether a
host has ever used TLS so that future calls will always use
TLS. */
fp = http_get_read_ptr (http);
if (!fp)
{
err = gpg_error (GPG_ERR_BUG);
goto leave;
}
/* Return the read stream and close the HTTP context. */
*r_fp = fp;
http_close (http, 1);
http = NULL;
leave:
http_close (http, 0);
http_session_release (session);
xfree (request_buffer);
return err;
}
/* Helper to evaluate the error code ERR from a send_request() call
with REQUEST. The function returns true if the caller shall try
again. TRIES_LEFT points to a variable to track the number of
retries; this function decrements it and won't return true if it is
down to zero. */
static int
handle_send_request_error (ctrl_t ctrl, gpg_error_t err, const char *request,
unsigned int *tries_left)
{
int retry = 0;
/* Fixme: Should we disable all hosts of a protocol family if a
* request for an address of that familiy returned ENETDOWN? */
switch (gpg_err_code (err))
{
case GPG_ERR_ECONNREFUSED:
if (tor_not_running_p (ctrl))
break; /* A retry does not make sense. */
/* Okay: Tor is up or --use-tor is not used. */
/*FALLTHRU*/
case GPG_ERR_ENETUNREACH:
case GPG_ERR_ENETDOWN:
case GPG_ERR_UNKNOWN_HOST:
case GPG_ERR_NETWORK:
if (mark_host_dead (request) && *tries_left)
retry = 1;
break;
case GPG_ERR_ETIMEDOUT:
if (*tries_left)
{
log_info ("selecting a different host due to a timeout\n");
retry = 1;
}
break;
case GPG_ERR_EACCES:
if (dirmngr_use_tor ())
{
log_info ("(Tor configuration problem)\n");
dirmngr_status (ctrl, "WARNING", "tor_config_problem 0",
"Please check that the \"SocksPort\" flag "
"\"IPv6Traffic\" is set in torrc", NULL);
}
break;
default:
break;
}
if (*tries_left)
--*tries_left;
return retry;
}
/* Search the keyserver identified by URI for keys matching PATTERN.
On success R_FP has an open stream to read the data. If
R_HTTP_STATUS is not NULL, the http status code will be stored
there. */
gpg_error_t
ks_hkp_search (ctrl_t ctrl, parsed_uri_t uri, const char *pattern,
estream_t *r_fp, unsigned int *r_http_status)
{
gpg_error_t err;
KEYDB_SEARCH_DESC desc;
char fprbuf[2+40+1];
char *hostport = NULL;
char *request = NULL;
estream_t fp = NULL;
int reselect;
unsigned int httpflags;
char *httphost = NULL;
unsigned int tries = SEND_REQUEST_RETRIES;
*r_fp = NULL;
/* Remove search type indicator and adjust PATTERN accordingly.
Note that HKP keyservers like the 0x to be present when searching
by keyid. We need to re-format the fingerprint and keyids so to
remove the gpg specific force-use-of-this-key flag ("!"). */
err = classify_user_id (pattern, &desc, 1);
if (err)
return err;
switch (desc.mode)
{
case KEYDB_SEARCH_MODE_EXACT:
case KEYDB_SEARCH_MODE_SUBSTR:
case KEYDB_SEARCH_MODE_MAIL:
case KEYDB_SEARCH_MODE_MAILSUB:
pattern = desc.u.name;
break;
case KEYDB_SEARCH_MODE_SHORT_KID:
snprintf (fprbuf, sizeof fprbuf, "0x%08lX", (ulong)desc.u.kid[1]);
pattern = fprbuf;
break;
case KEYDB_SEARCH_MODE_LONG_KID:
snprintf (fprbuf, sizeof fprbuf, "0x%08lX%08lX",
(ulong)desc.u.kid[0], (ulong)desc.u.kid[1]);
pattern = fprbuf;
break;
case KEYDB_SEARCH_MODE_FPR16:
fprbuf[0] = '0';
fprbuf[1] = 'x';
bin2hex (desc.u.fpr, 16, fprbuf+2);
pattern = fprbuf;
break;
case KEYDB_SEARCH_MODE_FPR20:
case KEYDB_SEARCH_MODE_FPR:
fprbuf[0] = '0';
fprbuf[1] = 'x';
bin2hex (desc.u.fpr, 20, fprbuf+2);
pattern = fprbuf;
break;
default:
return gpg_error (GPG_ERR_INV_USER_ID);
}
/* Build the request string. */
reselect = 0;
again:
{
char *searchkey;
xfree (hostport); hostport = NULL;
xfree (httphost); httphost = NULL;
err = make_host_part (ctrl, uri->scheme, uri->host, uri->port,
reselect, uri->explicit_port,
&hostport, &httpflags, &httphost);
if (err)
goto leave;
searchkey = http_escape_string (pattern, EXTRA_ESCAPE_CHARS);
if (!searchkey)
{
err = gpg_error_from_syserror ();
goto leave;
}
xfree (request);
request = strconcat (hostport,
"/pks/lookup?op=index&options=mr&search=",
searchkey,
NULL);
xfree (searchkey);
if (!request)
{
err = gpg_error_from_syserror ();
goto leave;
}
}
/* Send the request. */
err = send_request (ctrl, request, hostport, httphost, httpflags,
NULL, NULL, &fp, r_http_status);
if (handle_send_request_error (ctrl, err, request, &tries))
{
reselect = 1;
goto again;
}
if (err)
goto leave;
err = dirmngr_status (ctrl, "SOURCE", hostport, NULL);
if (err)
goto leave;
/* Peek at the response. */
{
int c = es_getc (fp);
if (c == -1)
{
err = es_ferror (fp)?gpg_error_from_syserror ():gpg_error (GPG_ERR_EOF);
log_error ("error reading response: %s\n", gpg_strerror (err));
goto leave;
}
if (c == '<')
{
/* The document begins with a '<': Assume a HTML response,
which we don't support. */
err = gpg_error (GPG_ERR_UNSUPPORTED_ENCODING);
goto leave;
}
es_ungetc (c, fp);
}
/* Return the read stream. */
*r_fp = fp;
fp = NULL;
leave:
es_fclose (fp);
xfree (request);
xfree (hostport);
xfree (httphost);
return err;
}
/* Get the key described key the KEYSPEC string from the keyserver
identified by URI. On success R_FP has an open stream to read the
data. The data will be provided in a format GnuPG can import
(either a binary OpenPGP message or an armored one). */
gpg_error_t
ks_hkp_get (ctrl_t ctrl, parsed_uri_t uri, const char *keyspec, estream_t *r_fp)
{
gpg_error_t err;
KEYDB_SEARCH_DESC desc;
char kidbuf[2+40+1];
const char *exactname = NULL;
char *searchkey = NULL;
char *hostport = NULL;
char *request = NULL;
estream_t fp = NULL;
int reselect;
char *httphost = NULL;
unsigned int httpflags;
unsigned int tries = SEND_REQUEST_RETRIES;
*r_fp = NULL;
/* Remove search type indicator and adjust PATTERN accordingly.
Note that HKP keyservers like the 0x to be present when searching
by keyid. We need to re-format the fingerprint and keyids so to
remove the gpg specific force-use-of-this-key flag ("!"). */
err = classify_user_id (keyspec, &desc, 1);
if (err)
return err;
switch (desc.mode)
{
case KEYDB_SEARCH_MODE_SHORT_KID:
snprintf (kidbuf, sizeof kidbuf, "0x%08lX", (ulong)desc.u.kid[1]);
break;
case KEYDB_SEARCH_MODE_LONG_KID:
snprintf (kidbuf, sizeof kidbuf, "0x%08lX%08lX",
(ulong)desc.u.kid[0], (ulong)desc.u.kid[1]);
break;
case KEYDB_SEARCH_MODE_FPR20:
case KEYDB_SEARCH_MODE_FPR:
/* This is a v4 fingerprint. */
kidbuf[0] = '0';
kidbuf[1] = 'x';
bin2hex (desc.u.fpr, 20, kidbuf+2);
break;
case KEYDB_SEARCH_MODE_EXACT:
exactname = desc.u.name;
break;
case KEYDB_SEARCH_MODE_FPR16:
log_error ("HKP keyservers do not support v3 fingerprints\n");
default:
return gpg_error (GPG_ERR_INV_USER_ID);
}
searchkey = http_escape_string (exactname? exactname : kidbuf,
EXTRA_ESCAPE_CHARS);
if (!searchkey)
{
err = gpg_error_from_syserror ();
goto leave;
}
reselect = 0;
again:
/* Build the request string. */
xfree (hostport); hostport = NULL;
xfree (httphost); httphost = NULL;
err = make_host_part (ctrl, uri->scheme, uri->host, uri->port,
reselect, uri->explicit_port,
&hostport, &httpflags, &httphost);
if (err)
goto leave;
xfree (request);
request = strconcat (hostport,
"/pks/lookup?op=get&options=mr&search=",
searchkey,
exactname? "&exact=on":"",
NULL);
if (!request)
{
err = gpg_error_from_syserror ();
goto leave;
}
/* Send the request. */
err = send_request (ctrl, request, hostport, httphost, httpflags,
NULL, NULL, &fp, NULL);
if (handle_send_request_error (ctrl, err, request, &tries))
{
reselect = 1;
goto again;
}
if (err)
goto leave;
err = dirmngr_status (ctrl, "SOURCE", hostport, NULL);
if (err)
goto leave;
/* Return the read stream and close the HTTP context. */
*r_fp = fp;
fp = NULL;
leave:
es_fclose (fp);
xfree (request);
xfree (hostport);
xfree (httphost);
xfree (searchkey);
return err;
}
/* Callback parameters for put_post_cb. */
struct put_post_parm_s
{
char *datastring;
};
/* Helper for ks_hkp_put. */
static gpg_error_t
put_post_cb (void *opaque, http_t http)
{
struct put_post_parm_s *parm = opaque;
gpg_error_t err = 0;
estream_t fp;
size_t len;
fp = http_get_write_ptr (http);
len = strlen (parm->datastring);
es_fprintf (fp,
"Content-Type: application/x-www-form-urlencoded\r\n"
"Content-Length: %zu\r\n", len+8 /* 8 is for "keytext" */);
http_start_data (http);
if (es_fputs ("keytext=", fp) || es_write (fp, parm->datastring, len, NULL))
err = gpg_error_from_syserror ();
return err;
}
/* Send the key in {DATA,DATALEN} to the keyserver identified by URI. */
gpg_error_t
ks_hkp_put (ctrl_t ctrl, parsed_uri_t uri, const void *data, size_t datalen)
{
gpg_error_t err;
char *hostport = NULL;
char *request = NULL;
estream_t fp = NULL;
struct put_post_parm_s parm;
char *armored = NULL;
int reselect;
char *httphost = NULL;
unsigned int httpflags;
unsigned int tries = SEND_REQUEST_RETRIES;
parm.datastring = NULL;
err = armor_data (&armored, data, datalen);
if (err)
goto leave;
parm.datastring = http_escape_string (armored, EXTRA_ESCAPE_CHARS);
if (!parm.datastring)
{
err = gpg_error_from_syserror ();
goto leave;
}
xfree (armored);
armored = NULL;
/* Build the request string. */
reselect = 0;
again:
xfree (hostport); hostport = NULL;
xfree (httphost); httphost = NULL;
err = make_host_part (ctrl, uri->scheme, uri->host, uri->port,
reselect, uri->explicit_port,
&hostport, &httpflags, &httphost);
if (err)
goto leave;
xfree (request);
request = strconcat (hostport, "/pks/add", NULL);
if (!request)
{
err = gpg_error_from_syserror ();
goto leave;
}
/* Send the request. */
err = send_request (ctrl, request, hostport, httphost, 0,
put_post_cb, &parm, &fp, NULL);
if (handle_send_request_error (ctrl, err, request, &tries))
{
reselect = 1;
goto again;
}
if (err)
goto leave;
leave:
es_fclose (fp);
xfree (parm.datastring);
xfree (armored);
xfree (request);
xfree (hostport);
xfree (httphost);
return err;
}