/* call-agent.c - divert operations to the agent
* Copyright (C) 2001, 2002, 2003, 2005 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 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
#include
#include
#include
#ifdef HAVE_LOCALE_H
#include
#endif
#include "gpgsm.h"
#include
#include
#include "i18n.h"
#include "asshelp.h"
#include "keydb.h" /* fixme: Move this to import.c */
#include "membuf.h"
static assuan_context_t agent_ctx = NULL;
struct cipher_parm_s
{
assuan_context_t ctx;
const unsigned char *ciphertext;
size_t ciphertextlen;
};
struct genkey_parm_s
{
assuan_context_t ctx;
const unsigned char *sexp;
size_t sexplen;
};
struct learn_parm_s
{
int error;
assuan_context_t 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 (ctrl_t ctrl)
{
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. */
return start_new_gpg_agent (&agent_ctx,
GPG_ERR_SOURCE_DEFAULT,
opt.homedir,
opt.agent_program,
opt.display, opt.ttyname, opt.ttytype,
opt.lc_ctype, opt.lc_messages,
opt.xauthority, opt.pinentry_user_data,
opt.verbose, DBG_ASSUAN,
gpgsm_status2, ctrl);
}
static int
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 (ctrl_t ctrl, const char *keygrip, const char *desc,
unsigned char *digest, size_t digestlen, int digestalgo,
unsigned 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 (ctrl);
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 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 rc;
if (desc)
{
snprintf (line, DIM(line)-1, "SETKEYDESC %s", desc);
line[DIM(line)-1] = 0;
rc = assuan_transact (agent_ctx, line,
NULL, NULL, NULL, NULL, NULL, NULL);
if (rc)
return 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 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 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 ();
}
/* Call the scdaemon to do a sign operation using the key identified by
the hex string KEYID. */
int
gpgsm_scd_pksign (ctrl_t ctrl, const char *keyid, const char *desc,
unsigned char *digest, size_t digestlen, int digestalgo,
unsigned char **r_buf, size_t *r_buflen )
{
int rc, i;
char *p, line[ASSUAN_LINELENGTH];
membuf_t data;
size_t len;
const char *hashopt;
unsigned char *sigbuf;
size_t sigbuflen;
*r_buf = NULL;
switch(digestalgo)
{
case GCRY_MD_SHA1: hashopt = "--hash=sha1"; break;
case GCRY_MD_RMD160:hashopt = "--hash=rmd160"; break;
case GCRY_MD_MD5: hashopt = "--hash=md5"; break;
case GCRY_MD_SHA256:hashopt = "--hash=sha256"; break;
default:
return gpg_error (GPG_ERR_DIGEST_ALGO);
}
rc = start_agent (ctrl);
if (rc)
return rc;
if (digestlen*2 + 50 > DIM(line))
return gpg_error (GPG_ERR_GENERAL);
p = stpcpy (line, "SCD SETDATA " );
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 rc;
init_membuf (&data, 1024);
snprintf (line, DIM(line)-1, "SCD PKSIGN %s %s", hashopt, keyid);
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 rc;
}
sigbuf = get_membuf (&data, &sigbuflen);
/* Create an S-expression from it which is formatted like this:
"(7:sig-val(3:rsa(1:sSIGBUFLEN:SIGBUF)))" Fixme: If a card ever
creates non-RSA keys we need to change things. */
*r_buflen = 21 + 11 + sigbuflen + 4;
p = xtrymalloc (*r_buflen);
*r_buf = (unsigned char*)p;
if (!p)
{
xfree (sigbuf);
return 0;
}
p = stpcpy (p, "(7:sig-val(3:rsa(1:s" );
sprintf (p, "%u:", (unsigned int)sigbuflen);
p += strlen (p);
memcpy (p, sigbuf, sigbuflen);
p += sigbuflen;
strcpy (p, ")))");
xfree (sigbuf);
assert (gcry_sexp_canon_len (*r_buf, *r_buflen, NULL, NULL));
return 0;
}
/* Handle a CIPHERTEXT inquiry. Note, we only send the data,
assuan_transact talkes care of flushing and writing the end */
static int
inq_ciphertext_cb (void *opaque, const char *keyword)
{
struct cipher_parm_s *parm = opaque;
int 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 (ctrl_t ctrl, const char *keygrip, const char *desc,
ksba_const_sexp_t 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 *p, *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 (ctrl);
if (rc)
return rc;
rc = assuan_transact (agent_ctx, "RESET", NULL, NULL, NULL, NULL, NULL, NULL);
if (rc)
return 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 rc;
if (desc)
{
snprintf (line, DIM(line)-1, "SETKEYDESC %s", desc);
line[DIM(line)-1] = 0;
rc = assuan_transact (agent_ctx, line,
NULL, NULL, NULL, NULL, NULL, NULL);
if (rc)
return 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 rc;
}
put_membuf (&data, "", 1); /* Make sure it is 0 terminated. */
buf = get_membuf (&data, &len);
if (!buf)
return gpg_error (GPG_ERR_ENOMEM);
assert (len); /* (we forced Nul termination.) */
if (*buf == '(')
{
if (len < 13 || memcmp (buf, "(5:value", 8) ) /* "(5:valueN:D)\0" */
return gpg_error (GPG_ERR_INV_SEXP);
len -= 11; /* Count only the data of the second part. */
p = buf + 8; /* Skip leading parenthesis and the value tag. */
}
else
{
/* For compatibility with older gpg-agents handle the old style
incomplete S-exps. */
len--; /* Do not count the Nul. */
p = buf;
}
n = strtoul (p, &endp, 10);
if (!n || *endp != ':')
return gpg_error (GPG_ERR_INV_SEXP);
endp++;
if (endp-p+n > len)
return gpg_error (GPG_ERR_INV_SEXP); /* Oops: Inconsistent S-Exp. */
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 int
inq_genkey_parms (void *opaque, const char *keyword)
{
struct genkey_parm_s *parm = opaque;
int rc;
rc = assuan_send_data (parm->ctx, parm->sexp, parm->sexplen);
return rc;
}
/* Call the agent to generate a newkey */
int
gpgsm_agent_genkey (ctrl_t ctrl,
ksba_const_sexp_t keyparms, ksba_sexp_t *r_pubkey)
{
int rc;
struct genkey_parm_s gk_parm;
membuf_t data;
size_t len;
unsigned char *buf;
*r_pubkey = NULL;
rc = start_agent (ctrl);
if (rc)
return rc;
rc = assuan_transact (agent_ctx, "RESET", NULL, NULL, NULL, NULL, NULL, NULL);
if (rc)
return 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 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;
}
/* Call the agent to read the public key part for a given keygrip. If
FROMCARD is true, the key is directly read from the current
smartcard. In this case HEXKEYGRIP should be the keyID
(e.g. OPENPGP.3). */
int
gpgsm_agent_readkey (ctrl_t ctrl, int fromcard, const char *hexkeygrip,
ksba_sexp_t *r_pubkey)
{
int rc;
membuf_t data;
size_t len;
unsigned char *buf;
char line[ASSUAN_LINELENGTH];
*r_pubkey = NULL;
rc = start_agent (ctrl);
if (rc)
return rc;
rc = assuan_transact (agent_ctx, "RESET",NULL, NULL, NULL, NULL, NULL, NULL);
if (rc)
return rc;
snprintf (line, DIM(line)-1, "%sREADKEY %s",
fromcard? "SCD ":"", hexkeygrip);
line[DIM(line)-1] = 0;
init_membuf (&data, 1024);
rc = assuan_transact (agent_ctx, line,
membuf_data_cb, &data,
NULL, NULL, NULL, NULL);
if (rc)
{
xfree (get_membuf (&data, &len));
return 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;
}
static int
istrusted_status_cb (void *opaque, const char *line)
{
struct rootca_flags_s *flags = opaque;
if (!strncmp (line, "TRUSTLISTFLAG", 13) && (line[13]==' ' || !line[13]))
{
for (line += 13; *line == ' '; line++)
;
if (!strncmp (line, "relax", 5) && (line[5] == ' ' || !line[5]))
flags->relax = 1;
else if (!strncmp (line, "cm", 2) && (line[2] == ' ' || !line[2]))
flags->chain_model = 1;
}
return 0;
}
/* Ask the agent whether the certificate is in the list of trusted
keys. ROOTCA_FLAGS is guaranteed to be cleared on error. */
int
gpgsm_agent_istrusted (ctrl_t ctrl, ksba_cert_t cert,
struct rootca_flags_s *rootca_flags)
{
int rc;
char *fpr;
char line[ASSUAN_LINELENGTH];
memset (rootca_flags, 0, sizeof *rootca_flags);
rc = start_agent (ctrl);
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,
istrusted_status_cb, rootca_flags);
if (!rc)
rootca_flags->valid = 1;
return rc;
}
/* Ask the agent to mark CERT as a trusted Root-CA one */
int
gpgsm_agent_marktrusted (ctrl_t ctrl, ksba_cert_t cert)
{
int rc;
char *fpr, *dn;
char line[ASSUAN_LINELENGTH];
rc = start_agent (ctrl);
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 rc;
}
/* Ask the agent whether the a corresponding secret key is available
for the given keygrip */
int
gpgsm_agent_havekey (ctrl_t ctrl, const char *hexkeygrip)
{
int rc;
char line[ASSUAN_LINELENGTH];
rc = start_agent (ctrl);
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 rc;
}
static int
learn_cb (void *opaque, const void *buffer, size_t length)
{
struct learn_parm_s *parm = opaque;
size_t len;
char *buf;
ksba_cert_t 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 */
rc = ksba_cert_new (&cert);
if (rc)
{
parm->error = rc;
return 0;
}
rc = ksba_cert_init_from_mem (cert, buf, len);
if (rc)
{
log_error ("failed to parse a certificate: %s\n", gpg_strerror (rc));
ksba_cert_release (cert);
parm->error = 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 (ctrl_t ctrl)
{
int rc;
struct learn_parm_s learn_parm;
membuf_t data;
size_t len;
rc = start_agent (ctrl);
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 rc;
return learn_parm.error;
}
/* Ask the agent to change the passphrase of the key identified by
HEXKEYGRIP. If DESC is not NULL, display instead of the default
description message. */
int
gpgsm_agent_passwd (ctrl_t ctrl, const char *hexkeygrip, const char *desc)
{
int rc;
char line[ASSUAN_LINELENGTH];
rc = start_agent (ctrl);
if (rc)
return rc;
if (!hexkeygrip || strlen (hexkeygrip) != 40)
return gpg_error (GPG_ERR_INV_VALUE);
if (desc)
{
snprintf (line, DIM(line)-1, "SETKEYDESC %s", desc);
line[DIM(line)-1] = 0;
rc = assuan_transact (agent_ctx, line,
NULL, NULL, NULL, NULL, NULL, NULL);
if (rc)
return rc;
}
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 rc;
}
/* Ask the agent to pop up a confirmation dialog with the text DESC
and an okay and cancel button. */
gpg_error_t
gpgsm_agent_get_confirmation (ctrl_t ctrl, const char *desc)
{
int rc;
char line[ASSUAN_LINELENGTH];
rc = start_agent (ctrl);
if (rc)
return rc;
snprintf (line, DIM(line)-1, "GET_CONFIRMATION %s", desc);
line[DIM(line)-1] = 0;
rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
return rc;
}