gnupg/agent/genkey.c

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/* pksign.c - Generate a keypair
* Copyright (C) 2002, 2003, 2004 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 <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <assert.h>
#include "agent.h"
#include "i18n.h"
static int
store_key (gcry_sexp_t private, const char *passphrase, int force)
{
int rc;
unsigned char *buf;
size_t len;
unsigned char grip[20];
if ( !gcry_pk_get_keygrip (private, grip) )
{
log_error ("can't calculate keygrip\n");
return gpg_error (GPG_ERR_GENERAL);
}
len = gcry_sexp_sprint (private, GCRYSEXP_FMT_CANON, NULL, 0);
assert (len);
buf = gcry_malloc_secure (len);
if (!buf)
return out_of_core ();
len = gcry_sexp_sprint (private, GCRYSEXP_FMT_CANON, buf, len);
assert (len);
if (passphrase)
{
unsigned char *p;
rc = agent_protect (buf, passphrase, &p, &len);
if (rc)
{
xfree (buf);
return rc;
}
xfree (buf);
buf = p;
}
rc = agent_write_private_key (grip, buf, len, force);
xfree (buf);
return rc;
}
/* Check whether the passphrase PW is suitable. Returns 0 if the
passphrase is suitable and true if it is not and the user should be
asked to provide a different one. */
int
check_passphrase_constraints (ctrl_t ctrl, const char *pw)
{
gpg_error_t err;
unsigned int minlen = opt.min_passphrase_len;
if (!pw)
pw = "";
if (utf8_charcount (pw) < minlen )
{
char *desc = xtryasprintf
( ngettext ("Warning: You have entered a passphrase that%%0A"
"is obviously not secure. A passphrase should%%0A"
"be at least %u character long.",
"Warning: You have entered a passphrase that%%0A"
"is obviously not secure. A passphrase should%%0A"
"be at least %u characters long.", minlen), minlen );
if (!desc)
return gpg_error_from_syserror ();
err = agent_get_confirmation (ctrl, desc,
_("Take this one anyway"),
_("Enter new passphrase"));
xfree (desc);
if (err)
return err;
}
return 0;
}
/* Callback function to compare the first entered PIN with the one
currently being entered. */
static int
reenter_compare_cb (struct pin_entry_info_s *pi)
{
const char *pin1 = pi->check_cb_arg;
if (!strcmp (pin1, pi->pin))
return 0; /* okay */
return -1;
}
/* Generate a new keypair according to the parameters given in
KEYPARAM */
int
agent_genkey (ctrl_t ctrl, const char *keyparam, size_t keyparamlen,
membuf_t *outbuf)
{
gcry_sexp_t s_keyparam, s_key, s_private, s_public;
struct pin_entry_info_s *pi, *pi2;
int rc;
size_t len;
char *buf;
rc = gcry_sexp_sscan (&s_keyparam, NULL, keyparam, keyparamlen);
if (rc)
{
log_error ("failed to convert keyparam: %s\n", gpg_strerror (rc));
return gpg_error (GPG_ERR_INV_DATA);
}
/* Get the passphrase now, cause key generation may take a while. */
{
const char *text1 = _("Please enter the passphrase to%0A"
"to protect your new key");
const char *text2 = _("Please re-enter this passphrase");
const char *initial_errtext = NULL;
pi = gcry_calloc_secure (2, sizeof (*pi) + 100);
pi2 = pi + (sizeof *pi + 100);
pi->max_length = 100;
pi->max_tries = 3;
pi2->max_length = 100;
pi2->max_tries = 3;
pi2->check_cb = reenter_compare_cb;
pi2->check_cb_arg = pi->pin;
next_try:
rc = agent_askpin (ctrl, text1, NULL, initial_errtext, pi);
initial_errtext = NULL;
if (!rc)
{
if (check_passphrase_constraints (ctrl, pi->pin))
{
pi->failed_tries = 0;
pi2->failed_tries = 0;
goto next_try;
}
rc = agent_askpin (ctrl, text2, NULL, NULL, pi2);
if (rc == -1)
{ /* The re-entered one did not match and the user did not
hit cancel. */
initial_errtext = _("does not match - try again");
goto next_try;
}
}
if (rc)
{
xfree (pi);
return rc;
}
if (!*pi->pin)
{
xfree (pi);
pi = NULL; /* User does not want a passphrase. */
}
}
rc = gcry_pk_genkey (&s_key, s_keyparam );
gcry_sexp_release (s_keyparam);
if (rc)
{
log_error ("key generation failed: %s\n", gpg_strerror (rc));
xfree (pi);
return rc;
}
/* break out the parts */
s_private = gcry_sexp_find_token (s_key, "private-key", 0);
if (!s_private)
{
log_error ("key generation failed: invalid return value\n");
gcry_sexp_release (s_key);
xfree (pi);
return gpg_error (GPG_ERR_INV_DATA);
}
s_public = gcry_sexp_find_token (s_key, "public-key", 0);
if (!s_public)
{
log_error ("key generation failed: invalid return value\n");
gcry_sexp_release (s_private);
gcry_sexp_release (s_key);
xfree (pi);
return gpg_error (GPG_ERR_INV_DATA);
}
gcry_sexp_release (s_key); s_key = NULL;
/* store the secret key */
if (DBG_CRYPTO)
log_debug ("storing private key\n");
rc = store_key (s_private, pi? pi->pin:NULL, 0);
xfree (pi); pi = NULL;
gcry_sexp_release (s_private);
if (rc)
{
gcry_sexp_release (s_public);
return rc;
}
/* return the public key */
if (DBG_CRYPTO)
log_debug ("returning public key\n");
len = gcry_sexp_sprint (s_public, GCRYSEXP_FMT_CANON, NULL, 0);
assert (len);
buf = xtrymalloc (len);
if (!buf)
{
gpg_error_t tmperr = out_of_core ();
gcry_sexp_release (s_private);
gcry_sexp_release (s_public);
return tmperr;
}
len = gcry_sexp_sprint (s_public, GCRYSEXP_FMT_CANON, buf, len);
assert (len);
put_membuf (outbuf, buf, len);
gcry_sexp_release (s_public);
xfree (buf);
return 0;
}
/* Apply a new passpahrse to the key S_SKEY and store it. */
int
agent_protect_and_store (ctrl_t ctrl, gcry_sexp_t s_skey)
{
struct pin_entry_info_s *pi, *pi2;
int rc;
{
const char *text1 = _("Please enter the new passphrase");
const char *text2 = _("Please re-enter this passphrase");
const char *initial_errtext = NULL;
pi = gcry_calloc_secure (2, sizeof (*pi) + 100);
pi2 = pi + (sizeof *pi + 100);
pi->max_length = 100;
pi->max_tries = 3;
pi2->max_length = 100;
pi2->max_tries = 3;
pi2->check_cb = reenter_compare_cb;
pi2->check_cb_arg = pi->pin;
next_try:
rc = agent_askpin (ctrl, text1, NULL, initial_errtext, pi);
initial_errtext = NULL;
if (!rc)
{
if (check_passphrase_constraints (ctrl, pi->pin))
{
pi->failed_tries = 0;
pi2->failed_tries = 0;
goto next_try;
}
rc = agent_askpin (ctrl, text2, NULL, NULL, pi2);
if (rc == -1)
{ /* The re-entered one did not match and the user did not
hit cancel. */
initial_errtext = _("does not match - try again");
goto next_try;
}
}
if (rc)
{
xfree (pi);
return rc;
}
if (!*pi->pin)
{
xfree (pi);
pi = NULL; /* User does not want a passphrase. */
}
}
rc = store_key (s_skey, pi? pi->pin:NULL, 1);
xfree (pi);
return 0;
}