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gnupg/g10/call-agent.c

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/* 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
*/
#if 0 /* lety Emacs display a red warning */
#error fixme: this shares a lof of code with the file in ../sm
#endif
#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 <assuan.h>
#include "gpg.h"
#include "util.h"
#include "membuf.h"
#include "options.h"
#include "i18n.h"
#include "call-agent.h"
#ifndef DBG_ASSUAN
# define DBG_ASSUAN 1
#endif
static ASSUAN_CONTEXT agent_ctx = NULL;
static int force_pipe_server = 1; /* FIXME: set this back to 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;
};
/* 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. */
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_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 gpg_error_from_errno (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 gpg_error_from_errno (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 gpg_error_from_errno (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 gpg_error_from_errno (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 = gpg_error_from_errno (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 gpg_error_from_errno (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 = gpg_error_from_errno (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;
}
/* Return a new malloced string by unescaping the string S. Escaping
is percent escaping and '+'/space mapping. A binary nul will
silently be replaced by a 0xFF. Function returns NULL to indicate
an out of memory status. */
static char *
unescape_status_string (const unsigned char *s)
{
char *buffer, *d;
buffer = d = xtrymalloc (strlen (s)+1);
if (!buffer)
return NULL;
while (*s)
{
if (*s == '%' && s[1] && s[2])
{
s++;
*d = xtoi_2 (s);
if (!*d)
*d = '\xff';
d++;
s += 2;
}
else if (*s == '+')
{
*d++ = ' ';
s++;
}
else
*d++ = *s++;
}
*d = 0;
return buffer;
}
/* Take a 20 byte hexencoded string and put it into the the provided
20 byte buffer FPR in binary format. */
static int
unhexify_fpr (const char *hexstr, unsigned char *fpr)
{
const char *s;
int n;
for (s=hexstr, n=0; hexdigitp (s); s++, n++)
;
if (*s || (n != 40))
return 0; /* no fingerprint (invalid or wrong length). */
n /= 2;
for (s=hexstr, n=0; *s; s += 2, n++)
fpr[n] = xtoi_2 (s);
return 1; /* okay */
}
/* Take the serial number from LINE and return it verbatim in a newly
allocated string. We make sure that only hex characters are
returned. */
static char *
store_serialno (const char *line)
{
const char *s;
char *p;
for (s=line; hexdigitp (s); s++)
;
p = xtrymalloc (s + 1 - line);
if (p)
{
memcpy (p, line, s-line);
p[s-line] = 0;
}
return p;
}
#if 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 new key */
int
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;
}
#endif /*0*/
/* Ask the agent whether the corresponding secret key is available for
the given keygrip. */
int
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);
}
/* Release the card info structure INFO. */
void
agent_release_card_info (struct agent_card_info_s *info)
{
if (!info)
return;
xfree (info->serialno); info->serialno = NULL;
xfree (info->disp_name); info->disp_name = NULL;
xfree (info->disp_lang); info->disp_lang = NULL;
xfree (info->pubkey_url); info->pubkey_url = NULL;
xfree (info->login_data); info->login_data = NULL;
info->fpr1valid = info->fpr2valid = info->fpr3valid = 0;
}
static AssuanError
learn_status_cb (void *opaque, const char *line)
{
struct agent_card_info_s *parm = opaque;
const char *keyword = line;
int keywordlen;
int i;
for (keywordlen=0; *line && !spacep (line); line++, keywordlen++)
;
while (spacep (line))
line++;
if (keywordlen == 8 && !memcmp (keyword, "SERIALNO", keywordlen))
{
parm->serialno = store_serialno (line);
}
else if (keywordlen == 9 && !memcmp (keyword, "DISP-NAME", keywordlen))
{
parm->disp_name = unescape_status_string (line);
}
else if (keywordlen == 9 && !memcmp (keyword, "DISP-LANG", keywordlen))
{
parm->disp_lang = unescape_status_string (line);
}
else if (keywordlen == 8 && !memcmp (keyword, "DISP-SEX", keywordlen))
{
parm->disp_sex = *line == '1'? 1 : *line == '2' ? 2: 0;
}
else if (keywordlen == 10 && !memcmp (keyword, "PUBKEY-URL", keywordlen))
{
parm->pubkey_url = unescape_status_string (line);
}
else if (keywordlen == 10 && !memcmp (keyword, "LOGIN-DATA", keywordlen))
{
parm->login_data = unescape_status_string (line);
}
else if (keywordlen == 11 && !memcmp (keyword, "SIG-COUNTER", keywordlen))
{
parm->sig_counter = strtoul (line, NULL, 0);
}
else if (keywordlen == 10 && !memcmp (keyword, "CHV-STATUS", keywordlen))
{
char *p, *buf;
buf = p = unescape_status_string (line);
if (buf)
{
while (spacep (p))
p++;
parm->chv1_cached = atoi (p);
while (!spacep (p))
p++;
while (spacep (p))
p++;
for (i=0; *p && i < 3; i++)
{
parm->chvmaxlen[i] = atoi (p);
while (!spacep (p))
p++;
while (spacep (p))
p++;
}
for (i=0; *p && i < 3; i++)
{
parm->chvretry[i] = atoi (p);
while (!spacep (p))
p++;
while (spacep (p))
p++;
}
xfree (buf);
}
}
else if (keywordlen == 7 && !memcmp (keyword, "KEY-FPR", keywordlen))
{
int no = atoi (line);
while (!spacep (line))
line++;
while (spacep (line))
line++;
if (no == 1)
parm->fpr1valid = unhexify_fpr (line, parm->fpr1);
else if (no == 2)
parm->fpr2valid = unhexify_fpr (line, parm->fpr2);
else if (no == 3)
parm->fpr3valid = unhexify_fpr (line, parm->fpr3);
}
return 0;
}
/* Call the agent to learn about a smartcard */
int
agent_learn (struct agent_card_info_s *info)
{
int rc;
rc = start_agent ();
if (rc)
return rc;
memset (info, 0, sizeof *info);
rc = assuan_transact (agent_ctx, "LEARN --send",
NULL, NULL, NULL, NULL,
learn_status_cb, info);
return map_assuan_err (rc);
}
/* Send an setattr command to the SCdaemon. */
int
agent_scd_setattr (const char *name,
const unsigned char *value, size_t valuelen)
{
int rc;
char line[ASSUAN_LINELENGTH];
char *p;
if (!*name || !valuelen)
return gpg_error (GPG_ERR_INV_VALUE);
/* We assume that NAME does not need escaping. */
if (12 + strlen (name) > DIM(line)-1)
return gpg_error (GPG_ERR_TOO_LARGE);
p = stpcpy (stpcpy (line, "SCD SETATTR "), name);
*p++ = ' ';
for (; valuelen; value++, valuelen--)
{
if (p >= line + DIM(line)-5 )
return gpg_error (GPG_ERR_TOO_LARGE);
if (*value < ' ' || *value == '+' || *value == '%')
{
sprintf (p, "%%%02X", *value);
p += 3;
}
else if (*value == ' ')
*p++ = '+';
else
*p++ = *value;
}
*p = 0;
rc = start_agent ();
if (rc)
return rc;
rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
return map_assuan_err (rc);
}
/* Status callback for the SCD GENKEY command. */
static AssuanError
scd_genkey_cb (void *opaque, const char *line)
{
struct agent_card_genkey_s *parm = opaque;
const char *keyword = line;
int keywordlen;
gpg_error_t rc;
log_debug ("got status line `%s'\n", line);
for (keywordlen=0; *line && !spacep (line); line++, keywordlen++)
;
while (spacep (line))
line++;
if (keywordlen == 7 && !memcmp (keyword, "KEY-FPR", keywordlen))
{
parm->fprvalid = unhexify_fpr (line, parm->fpr);
}
if (keywordlen == 8 && !memcmp (keyword, "KEY-DATA", keywordlen))
{
gcry_mpi_t a;
const char *name = line;
while (!spacep (line))
line++;
while (spacep (line))
line++;
rc = gcry_mpi_scan (&a, GCRYMPI_FMT_HEX, line, 0, NULL);
if (rc)
log_error ("error parsing received key data: %s\n", gpg_strerror (rc));
else if (*name == 'n' && spacep (name+1))
parm->n = a;
else if (*name == 'e' && spacep (name+1))
parm->e = a;
else
{
log_info ("unknown parameter name in received key data\n");
gcry_mpi_release (a);
}
}
else if (keywordlen == 14 && !memcmp (keyword,"KEY-CREATED-AT", keywordlen))
{
parm->created_at = (u32)strtoul (line, NULL, 10);
}
return 0;
}
/* Send a GENKEY command to the SCdaemon. */
int
agent_scd_genkey (struct agent_card_genkey_s *info, int keyno, int force)
{
int rc;
char line[ASSUAN_LINELENGTH];
rc = start_agent ();
if (rc)
return rc;
memset (info, 0, sizeof *info);
snprintf (line, DIM(line)-1, "SCD GENKEY %s%d",
force? "--force ":"", keyno);
line[DIM(line)-1] = 0;
memset (info, 0, sizeof *info);
rc = assuan_transact (agent_ctx, line,
NULL, NULL, NULL, NULL,
scd_genkey_cb, info);
return map_assuan_err (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;
}
/* Send a sign command to the scdaemon via gpg-agent's pass thru
mechanism. */
int
agent_scd_pksign (const char *serialno, int hashalgo,
const unsigned char *indata, size_t indatalen,
char **r_buf, size_t *r_buflen)
{
int rc, i;
char *p, line[ASSUAN_LINELENGTH];
membuf_t data;
size_t len;
/* Note, hashalgo is not yet used but hardwired to SHA1 in SCdaemon. */
*r_buf = NULL;
*r_buflen = 0;
rc = start_agent ();
if (rc)
return rc;
if (indatalen*2 + 50 > DIM(line))
return gpg_error (GPG_ERR_GENERAL);
sprintf (line, "SCD SETDATA ");
p = line + strlen (line);
for (i=0; i < indatalen ; i++, p += 2 )
sprintf (p, "%02X", indata[i]);
rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
if (rc)
return map_assuan_err (rc);
init_membuf (&data, 1024);
#if 0
if (!hashalgo) /* Temporary test hack. */
snprintf (line, DIM(line)-1, "SCD PKAUTH %s", serialno);
else
#endif
snprintf (line, DIM(line)-1, "SCD PKSIGN %s", serialno);
line[DIM(line)-1] = 0;
rc = assuan_transact (agent_ctx, line, 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);
return 0;
}
/* Decrypt INDATA of length INDATALEN using the card identified by
SERIALNO. Return the plaintext in a nwly allocated buffer stored
at the address of R_BUF.
Note, we currently support only RSA or more exactly algorithms
taking one input data element. */
int
agent_scd_pkdecrypt (const char *serialno,
const unsigned char *indata, size_t indatalen,
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;
/* FIXME: use secure memory where appropriate */
if (indatalen*2 + 50 > DIM(line))
return gpg_error (GPG_ERR_GENERAL);
sprintf (line, "SCD SETDATA ");
p = line + strlen (line);
for (i=0; i < indatalen ; i++, p += 2 )
sprintf (p, "%02X", indata[i]);
rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
if (rc)
return map_assuan_err (rc);
init_membuf (&data, 1024);
snprintf (line, DIM(line)-1, "SCD PKDECRYPT %s", serialno);
line[DIM(line)-1] = 0;
rc = assuan_transact (agent_ctx, line,
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 (!*r_buf)
return gpg_error (GPG_ERR_ENOMEM);
return 0;
}
/* Change the PIN of an OpenPGP card or reset the retry counter.
CHVNO 1: Change the digital signature PIN
2: Change the decryption and authentication PIN
3: Change the admin PIN
101: Set a new digital signature PIN and reset the retry counter
102: Set a decryption and authentication PIN
and reset the retry counter
*/
int
agent_scd_change_pin (int chvno)
{
int rc;
char line[ASSUAN_LINELENGTH];
const char *reset = "";
if (chvno >= 100)
reset = "--reset";
chvno %= 100;
rc = start_agent ();
if (rc)
return rc;
snprintf (line, DIM(line)-1, "SCD PASSWD %s %d", reset, chvno);
line[DIM(line)-1] = 0;
rc = assuan_transact (agent_ctx, line, NULL, NULL,
NULL, NULL, NULL, NULL);
return map_assuan_err (rc);
}