/* call-agent.c - divert operations to the agent
* Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc.
*
* 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 2 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, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <time.h>
#include <assert.h>
#ifdef HAVE_LOCALE_H
#include <locale.h>
#endif
#include "gpgsm.h"
#include <gcrypt.h>
#include <assuan.h>
#include "i18n.h"
#include "keydb.h" /* fixme: Move this to import.c */
#include "../common/membuf.h"
static ASSUAN_CONTEXT agent_ctx = NULL;
static int force_pipe_server = 0;
struct cipher_parm_s {
ASSUAN_CONTEXT ctx;
const char *ciphertext;
size_t ciphertextlen;
};
struct genkey_parm_s {
ASSUAN_CONTEXT ctx;
const char *sexp;
size_t sexplen;
};
struct learn_parm_s {
int error;
ASSUAN_CONTEXT ctx;
membuf_t *data;
};
/* Try to connect to the agent via socket or fork it off and work by
pipes. Handle the server's initial greeting */
static int
start_agent (void)
{
int rc = 0;
char *infostr, *p;
ASSUAN_CONTEXT ctx;
char *dft_display = NULL;
char *dft_ttyname = NULL;
char *dft_ttytype = NULL;
char *old_lc = NULL;
char *dft_lc = NULL;
if (agent_ctx)
return 0; /* fixme: We need a context for each thread or serialize
the access to the agent (which is suitable given that
the agent is not MT */
infostr = force_pipe_server? NULL : getenv ("GPG_AGENT_INFO");
if (!infostr)
{
const char *pgmname;
const char *argv[3];
int no_close_list[3];
int i;
if (opt.verbose)
log_info (_("no running gpg-agent - starting one\n"));
if (fflush (NULL))
{
gpg_error_t tmperr = gpg_error (gpg_err_code_from_errno (errno));
log_error ("error flushing pending output: %s\n", strerror (errno));
return tmperr;
}
if (!opt.agent_program || !*opt.agent_program)
opt.agent_program = GNUPG_DEFAULT_AGENT;
if ( !(pgmname = strrchr (opt.agent_program, '/')))
pgmname = opt.agent_program;
else
pgmname++;
argv[0] = pgmname;
argv[1] = "--server";
argv[2] = NULL;
i=0;
if (log_get_fd () != -1)
no_close_list[i++] = log_get_fd ();
no_close_list[i++] = fileno (stderr);
no_close_list[i] = -1;
/* connect to the agent and perform initial handshaking */
rc = assuan_pipe_connect (&ctx, opt.agent_program, (char**)argv,
no_close_list);
}
else
{
int prot;
int pid;
infostr = xstrdup (infostr);
if ( !(p = strchr (infostr, ':')) || p == infostr)
{
log_error (_("malformed GPG_AGENT_INFO environment variable\n"));
xfree (infostr);
force_pipe_server = 1;
return start_agent ();
}
*p++ = 0;
pid = atoi (p);
while (*p && *p != ':')
p++;
prot = *p? atoi (p+1) : 0;
if (prot != 1)
{
log_error (_("gpg-agent protocol version %d is not supported\n"),
prot);
xfree (infostr);
force_pipe_server = 1;
return start_agent ();
}
rc = assuan_socket_connect (&ctx, infostr, pid);
xfree (infostr);
if (rc == ASSUAN_Connect_Failed)
{
log_error (_("can't connect to the agent - trying fall back\n"));
force_pipe_server = 1;
return start_agent ();
}
}
if (rc)
{
log_error ("can't connect to the agent: %s\n", assuan_strerror (rc));
return gpg_error (GPG_ERR_NO_AGENT);
}
agent_ctx = ctx;
if (DBG_ASSUAN)
log_debug ("connection to agent established\n");
rc = assuan_transact (agent_ctx, "RESET", NULL, NULL, NULL, NULL, NULL, NULL);
if (rc)
return map_assuan_err (rc);
dft_display = getenv ("DISPLAY");
if (opt.display || dft_display)
{
char *optstr;
if (asprintf (&optstr, "OPTION display=%s",
opt.display ? opt.display : dft_display) < 0)
return OUT_OF_CORE (errno);
rc = assuan_transact (agent_ctx, optstr, NULL, NULL, NULL, NULL, NULL,
NULL);
free (optstr);
if (rc)
return map_assuan_err (rc);
}
if (!opt.ttyname)
{
dft_ttyname = getenv ("GPG_TTY");
if ((!dft_ttyname || !*dft_ttyname) && ttyname (0))
dft_ttyname = ttyname (0);
}
if (opt.ttyname || dft_ttyname)
{
char *optstr;
if (asprintf (&optstr, "OPTION ttyname=%s",
opt.ttyname ? opt.ttyname : dft_ttyname) < 0)
return OUT_OF_CORE (errno);
rc = assuan_transact (agent_ctx, optstr, NULL, NULL, NULL, NULL, NULL,
NULL);
free (optstr);
if (rc)
return map_assuan_err (rc);
}
dft_ttytype = getenv ("TERM");
if (opt.ttytype || (dft_ttyname && dft_ttytype))
{
char *optstr;
if (asprintf (&optstr, "OPTION ttytype=%s",
opt.ttyname ? opt.ttytype : dft_ttytype) < 0)
return OUT_OF_CORE (errno);
rc = assuan_transact (agent_ctx, optstr, NULL, NULL, NULL, NULL, NULL,
NULL);
free (optstr);
if (rc)
return map_assuan_err (rc);
}
#if defined(HAVE_SETLOCALE) && defined(LC_CTYPE)
old_lc = setlocale (LC_CTYPE, NULL);
if (old_lc)
{
old_lc = strdup (old_lc);
if (!old_lc)
return OUT_OF_CORE (errno);
}
dft_lc = setlocale (LC_CTYPE, "");
#endif
if (opt.lc_ctype || (dft_ttyname && dft_lc))
{
char *optstr;
if (asprintf (&optstr, "OPTION lc-ctype=%s",
opt.lc_ctype ? opt.lc_ctype : dft_lc) < 0)
rc = OUT_OF_CORE (errno);
else
{
rc = assuan_transact (agent_ctx, optstr, NULL, NULL, NULL, NULL, NULL,
NULL);
free (optstr);
if (rc)
rc = map_assuan_err (rc);
}
}
#if defined(HAVE_SETLOCALE) && defined(LC_CTYPE)
if (old_lc)
{
setlocale (LC_CTYPE, old_lc);
free (old_lc);
}
#endif
if (rc)
return rc;
#if defined(HAVE_SETLOCALE) && defined(LC_MESSAGES)
old_lc = setlocale (LC_MESSAGES, NULL);
if (old_lc)
{
old_lc = strdup (old_lc);
if (!old_lc)
return OUT_OF_CORE (errno);
}
dft_lc = setlocale (LC_MESSAGES, "");
#endif
if (opt.lc_messages || (dft_ttyname && dft_lc))
{
char *optstr;
if (asprintf (&optstr, "OPTION lc-messages=%s",
opt.lc_messages ? opt.lc_messages : dft_lc) < 0)
rc = OUT_OF_CORE (errno);
else
{
rc = assuan_transact (agent_ctx, optstr, NULL, NULL, NULL, NULL, NULL,
NULL);
free (optstr);
if (rc)
rc = map_assuan_err (rc);
}
}
#if defined(HAVE_SETLOCALE) && defined(LC_MESSAGES)
if (old_lc)
{
setlocale (LC_MESSAGES, old_lc);
free (old_lc);
}
#endif
return rc;
}
static AssuanError
membuf_data_cb (void *opaque, const void *buffer, size_t length)
{
membuf_t *data = opaque;
if (buffer)
put_membuf (data, buffer, length);
return 0;
}
/* Call the agent to do a sign operation using the key identified by
the hex string KEYGRIP. */
int
gpgsm_agent_pksign (const char *keygrip,
unsigned char *digest, size_t digestlen, int digestalgo,
char **r_buf, size_t *r_buflen )
{
int rc, i;
char *p, line[ASSUAN_LINELENGTH];
membuf_t data;
size_t len;
*r_buf = NULL;
rc = start_agent ();
if (rc)
return rc;
if (digestlen*2 + 50 > DIM(line))
return gpg_error (GPG_ERR_GENERAL);
rc = assuan_transact (agent_ctx, "RESET", NULL, NULL, NULL, NULL, NULL, NULL);
if (rc)
return map_assuan_err (rc);
snprintf (line, DIM(line)-1, "SIGKEY %s", keygrip);
line[DIM(line)-1] = 0;
rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
if (rc)
return map_assuan_err (rc);
sprintf (line, "SETHASH %d ", digestalgo);
p = line + strlen (line);
for (i=0; i < digestlen ; i++, p += 2 )
sprintf (p, "%02X", digest[i]);
rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
if (rc)
return map_assuan_err (rc);
init_membuf (&data, 1024);
rc = assuan_transact (agent_ctx, "PKSIGN",
membuf_data_cb, &data, NULL, NULL, NULL, NULL);
if (rc)
{
xfree (get_membuf (&data, &len));
return map_assuan_err (rc);
}
*r_buf = get_membuf (&data, r_buflen);
if (!gcry_sexp_canon_len (*r_buf, *r_buflen, NULL, NULL))
{
xfree (*r_buf); *r_buf = NULL;
return gpg_error (GPG_ERR_INV_VALUE);
}
return *r_buf? 0 : OUT_OF_CORE (errno);
}
/* Handle a CIPHERTEXT inquiry. Note, we only send the data,
assuan_transact talkes care of flushing and writing the end */
static AssuanError
inq_ciphertext_cb (void *opaque, const char *keyword)
{
struct cipher_parm_s *parm = opaque;
AssuanError rc;
assuan_begin_confidential (parm->ctx);
rc = assuan_send_data (parm->ctx, parm->ciphertext, parm->ciphertextlen);
assuan_end_confidential (parm->ctx);
return rc;
}
/* Call the agent to do a decrypt operation using the key identified by
the hex string KEYGRIP. */
int
gpgsm_agent_pkdecrypt (const char *keygrip,
KsbaConstSexp ciphertext,
char **r_buf, size_t *r_buflen )
{
int rc;
char line[ASSUAN_LINELENGTH];
membuf_t data;
struct cipher_parm_s cipher_parm;
size_t n, len;
char *buf, *endp;
size_t ciphertextlen;
if (!keygrip || strlen(keygrip) != 40 || !ciphertext || !r_buf || !r_buflen)
return gpg_error (GPG_ERR_INV_VALUE);
*r_buf = NULL;
ciphertextlen = gcry_sexp_canon_len (ciphertext, 0, NULL, NULL);
if (!ciphertextlen)
return gpg_error (GPG_ERR_INV_VALUE);
rc = start_agent ();
if (rc)
return rc;
rc = assuan_transact (agent_ctx, "RESET", NULL, NULL, NULL, NULL, NULL, NULL);
if (rc)
return map_assuan_err (rc);
assert ( DIM(line) >= 50 );
snprintf (line, DIM(line)-1, "SETKEY %s", keygrip);
line[DIM(line)-1] = 0;
rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
if (rc)
return map_assuan_err (rc);
init_membuf (&data, 1024);
cipher_parm.ctx = agent_ctx;
cipher_parm.ciphertext = ciphertext;
cipher_parm.ciphertextlen = ciphertextlen;
rc = assuan_transact (agent_ctx, "PKDECRYPT",
membuf_data_cb, &data,
inq_ciphertext_cb, &cipher_parm, NULL, NULL);
if (rc)
{
xfree (get_membuf (&data, &len));
return map_assuan_err (rc);
}
put_membuf (&data, "", 1); /* make sure it is 0 terminated */
buf = get_membuf (&data, &len);
if (!buf)
return gpg_error (GPG_ERR_ENOMEM);
/* FIXME: We would better a return a full S-exp and not just a part */
assert (len);
len--; /* remove the terminating 0 */
n = strtoul (buf, &endp, 10);
if (!n || *endp != ':')
return gpg_error (GPG_ERR_INV_SEXP);
endp++;
if (endp-buf+n > len)
return gpg_error (GPG_ERR_INV_SEXP); /* oops len does not
match internal len*/
memmove (buf, endp, n);
*r_buflen = n;
*r_buf = buf;
return 0;
}
/* Handle a KEYPARMS inquiry. Note, we only send the data,
assuan_transact takes care of flushing and writing the end */
static AssuanError
inq_genkey_parms (void *opaque, const char *keyword)
{
struct genkey_parm_s *parm = opaque;
AssuanError rc;
rc = assuan_send_data (parm->ctx, parm->sexp, parm->sexplen);
return rc;
}
/* Call the agent to generate a newkey */
int
gpgsm_agent_genkey (KsbaConstSexp keyparms, KsbaSexp *r_pubkey)
{
int rc;
struct genkey_parm_s gk_parm;
membuf_t data;
size_t len;
char *buf;
*r_pubkey = NULL;
rc = start_agent ();
if (rc)
return rc;
rc = assuan_transact (agent_ctx, "RESET", NULL, NULL, NULL, NULL, NULL, NULL);
if (rc)
return map_assuan_err (rc);
init_membuf (&data, 1024);
gk_parm.ctx = agent_ctx;
gk_parm.sexp = keyparms;
gk_parm.sexplen = gcry_sexp_canon_len (keyparms, 0, NULL, NULL);
if (!gk_parm.sexplen)
return gpg_error (GPG_ERR_INV_VALUE);
rc = assuan_transact (agent_ctx, "GENKEY",
membuf_data_cb, &data,
inq_genkey_parms, &gk_parm, NULL, NULL);
if (rc)
{
xfree (get_membuf (&data, &len));
return map_assuan_err (rc);
}
buf = get_membuf (&data, &len);
if (!buf)
return gpg_error (GPG_ERR_ENOMEM);
if (!gcry_sexp_canon_len (buf, len, NULL, NULL))
{
xfree (buf);
return gpg_error (GPG_ERR_INV_SEXP);
}
*r_pubkey = buf;
return 0;
}
/* Ask the agent whether the certificate is in the list of trusted
keys */
int
gpgsm_agent_istrusted (KsbaCert cert)
{
int rc;
char *fpr;
char line[ASSUAN_LINELENGTH];
rc = start_agent ();
if (rc)
return rc;
fpr = gpgsm_get_fingerprint_hexstring (cert, GCRY_MD_SHA1);
if (!fpr)
{
log_error ("error getting the fingerprint\n");
return gpg_error (GPG_ERR_GENERAL);
}
snprintf (line, DIM(line)-1, "ISTRUSTED %s", fpr);
line[DIM(line)-1] = 0;
xfree (fpr);
rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
return map_assuan_err (rc);
}
/* Ask the agent to mark CERT as a trusted Root-CA one */
int
gpgsm_agent_marktrusted (KsbaCert cert)
{
int rc;
char *fpr, *dn;
char line[ASSUAN_LINELENGTH];
rc = start_agent ();
if (rc)
return rc;
fpr = gpgsm_get_fingerprint_hexstring (cert, GCRY_MD_SHA1);
if (!fpr)
{
log_error ("error getting the fingerprint\n");
return gpg_error (GPG_ERR_GENERAL);
}
dn = ksba_cert_get_issuer (cert, 0);
if (!dn)
{
xfree (fpr);
return gpg_error (GPG_ERR_GENERAL);
}
snprintf (line, DIM(line)-1, "MARKTRUSTED %s S %s", fpr, dn);
line[DIM(line)-1] = 0;
ksba_free (dn);
xfree (fpr);
rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
return map_assuan_err (rc);
}
/* Ask the agent whether the a corresponding secret key is available
for the given keygrip */
int
gpgsm_agent_havekey (const char *hexkeygrip)
{
int rc;
char line[ASSUAN_LINELENGTH];
rc = start_agent ();
if (rc)
return rc;
if (!hexkeygrip || strlen (hexkeygrip) != 40)
return gpg_error (GPG_ERR_INV_VALUE);
snprintf (line, DIM(line)-1, "HAVEKEY %s", hexkeygrip);
line[DIM(line)-1] = 0;
rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
return map_assuan_err (rc);
}
static AssuanError
learn_cb (void *opaque, const void *buffer, size_t length)
{
struct learn_parm_s *parm = opaque;
size_t len;
char *buf;
KsbaCert cert;
int rc;
if (parm->error)
return 0;
if (buffer)
{
put_membuf (parm->data, buffer, length);
return 0;
}
/* END encountered - process what we have */
buf = get_membuf (parm->data, &len);
if (!buf)
{
parm->error = gpg_error (GPG_ERR_ENOMEM);
return 0;
}
/* FIXME: this should go into import.c */
cert = ksba_cert_new ();
if (!cert)
{
parm->error = gpg_error (GPG_ERR_ENOMEM);
return 0;
}
rc = ksba_cert_init_from_mem (cert, buf, len);
if (rc)
{
log_error ("failed to parse a certificate: %s\n", ksba_strerror (rc));
ksba_cert_release (cert);
parm->error = map_ksba_err (rc);
return 0;
}
rc = gpgsm_basic_cert_check (cert);
if (gpg_err_code (rc) == GPG_ERR_MISSING_CERT)
{ /* For later use we store it in the ephemeral database. */
log_info ("issuer certificate missing - storing as ephemeral\n");
keydb_store_cert (cert, 1, NULL);
}
else if (rc)
log_error ("invalid certificate: %s\n", gpg_strerror (rc));
else
{
int existed;
if (!keydb_store_cert (cert, 0, &existed))
{
if (opt.verbose > 1 && existed)
log_info ("certificate already in DB\n");
else if (opt.verbose && !existed)
log_info ("certificate imported\n");
}
}
ksba_cert_release (cert);
init_membuf (parm->data, 4096);
return 0;
}
/* Call the agent to learn about a smartcard */
int
gpgsm_agent_learn ()
{
int rc;
struct learn_parm_s learn_parm;
membuf_t data;
size_t len;
rc = start_agent ();
if (rc)
return rc;
init_membuf (&data, 4096);
learn_parm.error = 0;
learn_parm.ctx = agent_ctx;
learn_parm.data = &data;
rc = assuan_transact (agent_ctx, "LEARN --send",
learn_cb, &learn_parm,
NULL, NULL, NULL, NULL);
xfree (get_membuf (&data, &len));
if (rc)
return map_assuan_err (rc);
return learn_parm.error;
}
/* Ask the agent to change the passphrase of the key identified by HEXKEYGRIP. */
int
gpgsm_agent_passwd (const char *hexkeygrip)
{
int rc;
char line[ASSUAN_LINELENGTH];
rc = start_agent ();
if (rc)
return rc;
if (!hexkeygrip || strlen (hexkeygrip) != 40)
return gpg_error (GPG_ERR_INV_VALUE);
snprintf (line, DIM(line)-1, "PASSWD %s", hexkeygrip);
line[DIM(line)-1] = 0;
rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
return map_assuan_err (rc);
}