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Import OpenPGP keys into the agent.

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This commit is contained in:
Werner Koch 2010-08-31 15:58:39 +00:00
parent 71bc88fbae
commit 87fac99112
23 changed files with 1669 additions and 282 deletions
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15
agent/ChangeLog
View file

@ -1,3 +1,18 @@
2010-08-31 Werner Koch <wk@g10code.com>
* pksign.c (do_encode_dsa): Fix sign problem.
* findkey.c (agent_is_dsa_key): Adjust to actual usage.
2010-08-30 Werner Koch <wk@g10code.com>
* protect.c (s2k_hash_passphrase): New public function.
2010-08-27 Werner Koch <wk@g10code.com>
* command.c (cmd_import_key): Support OpenPGP keys.
* cvt-openpgp.h, cvt-openpgp.c: New. Some of the code is based on
code taken from g10/seckey-cert.c.
2010-08-26 Werner Koch <wk@g10code.com>
* command-ssh.c (open_control_file): Use estream to create the file.

1
agent/Makefile.am
View file

@ -46,6 +46,7 @@ gpg_agent_SOURCES = \
protect.c \
trustlist.c \
divert-scd.c \
cvt-openpgp.c cvt-openpgp.h \
call-scd.c \
learncard.c

9
agent/agent.h
View file

@ -171,8 +171,8 @@ struct pin_entry_info_s
int with_qualitybar; /* Set if the quality bar should be displayed. */
int (*check_cb)(struct pin_entry_info_s *); /* CB used to check the PIN */
void *check_cb_arg; /* optional argument which might be of use in the CB */
const char *cb_errtext; /* used by the cb to displaye a specific error */
size_t max_length; /* allocated length of the buffer */
const char *cb_errtext; /* used by the cb to display a specific error */
size_t max_length; /* allocated length of the buffer */
char pin[1];
};
@ -306,6 +306,11 @@ int agent_get_shadow_info (const unsigned char *shadowkey,
unsigned char const **shadow_info);
gpg_error_t parse_shadow_info (const unsigned char *shadow_info,
char **r_hexsn, char **r_idstr);
gpg_error_t s2k_hash_passphrase (const char *passphrase, int hashalgo,
int s2kmode,
const unsigned char *s2ksalt,
unsigned int s2kcount,
unsigned char *key, size_t keylen);
/*-- trustlist.c --*/

80
agent/command.c
View file

@ -37,7 +37,7 @@
#include "agent.h"
#include <assuan.h>
#include "i18n.h"
#include "cvt-openpgp.h"
/* Maximum allowed size of the inquired ciphertext. */
@ -357,6 +357,12 @@ leave_cmd (assuan_context_t ctx, gpg_error_t err)
const char *name = assuan_get_command_name (ctx);
if (!name)
name = "?";
/* Most code from common/ does not know the error source, thus
we fix this here. */
if (gpg_err_source (err) == GPG_ERR_SOURCE_UNKNOWN)
err = gpg_err_make (GPG_ERR_SOURCE_DEFAULT, gpg_err_code (err));
if (gpg_err_source (err) == GPG_ERR_SOURCE_DEFAULT)
log_error ("command '%s' failed: %s\n", name,
gpg_strerror (err));
@ -566,8 +572,8 @@ cmd_sigkey (assuan_context_t ctx, char *line)
static const char hlp_setkeydesc[] =
"SETKEYDESC plus_percent_escaped_string\n"
"\n"
"Set a description to be used for the next PKSIGN, PKDECRYPT or EXPORT_KEY\n"
"operation if this operation requires the entry of a passphrase. If\n"
"Set a description to be used for the next PKSIGN, PKDECRYPT, IMPORT_KEY\n"
"or EXPORT_KEY operation if this operation requires a passphrase. If\n"
"this command is not used a default text will be used. Note, that\n"
"this description implictly selects the label used for the entry\n"
"box; if the string contains the string PIN (which in general will\n"
@ -575,8 +581,8 @@ static const char hlp_setkeydesc[] =
"\"passphrase\" is used. The description string should not contain\n"
"blanks unless they are percent or '+' escaped.\n"
"\n"
"The description is only valid for the next PKSIGN, PKDECRYPT or\n"
"EXPORT_KEY operation.";
"The description is only valid for the next PKSIGN, PKDECRYPT,\n"
"IMPORT_KEY or EXPORT_KEY operation.";
static gpg_error_t
cmd_setkeydesc (assuan_context_t ctx, char *line)
{
@ -1478,6 +1484,7 @@ cmd_import_key (assuan_context_t ctx, char *line)
unsigned char *finalkey = NULL;
size_t finalkeylen;
unsigned char grip[20];
gcry_sexp_t openpgp_sexp = NULL;
(void)line;
@ -1528,20 +1535,58 @@ cmd_import_key (assuan_context_t ctx, char *line)
err = keygrip_from_canon_sexp (key, realkeylen, grip);
if (err)
goto leave;
if (!agent_key_available (grip))
{
err = gpg_error (GPG_ERR_EEXIST);
goto leave;
/* This might be due to an unsupported S-expression format.
Check whether this is openpgp-private-key and trigger that
import code. */
if (!gcry_sexp_sscan (&openpgp_sexp, NULL, key, realkeylen))
{
const char *tag;
size_t taglen;
tag = gcry_sexp_nth_data (openpgp_sexp, 0, &taglen);
if (tag && taglen == 19 && !memcmp (tag, "openpgp-private-key", 19))
;
else
{
gcry_sexp_release (openpgp_sexp);
openpgp_sexp = NULL;
}
}
if (!openpgp_sexp)
goto leave; /* Note that ERR is still set. */
}
err = agent_ask_new_passphrase
(ctrl, _("Please enter the passphrase to protect the "
"imported object within the GnuPG system."),
&passphrase);
if (err)
goto leave;
if (openpgp_sexp)
{
/* In most cases the key is encrypted and thus the conversion
function from the OpenPGP format to our internal format will
ask for a passphrase. That passphrase will be returned and
used to protect the key using the same code as for regular
key import. */
err = convert_openpgp (ctrl, openpgp_sexp, grip,
ctrl->server_local->keydesc,
&key, &passphrase);
if (err)
goto leave;
realkeylen = gcry_sexp_canon_len (key, keylen, NULL, &err);
if (!realkeylen)
goto leave; /* Invalid canonical encoded S-expression. */
}
else
{
if (!agent_key_available (grip))
err = gpg_error (GPG_ERR_EEXIST);
else
err = agent_ask_new_passphrase
(ctrl, _("Please enter the passphrase to protect the "
"imported object within the GnuPG system."),
&passphrase);
if (err)
goto leave;
}
if (passphrase)
{
@ -1553,11 +1598,14 @@ cmd_import_key (assuan_context_t ctx, char *line)
err = agent_write_private_key (grip, key, realkeylen, 0);
leave:
gcry_sexp_release (openpgp_sexp);
xfree (finalkey);
xfree (passphrase);
xfree (key);
gcry_cipher_close (cipherhd);
xfree (wrappedkey);
xfree (ctrl->server_local->keydesc);
ctrl->server_local->keydesc = NULL;
return leave_cmd (ctx, err);
}

807
agent/cvt-openpgp.c Normal file
View file

@ -0,0 +1,807 @@
/* cvt-openpgp.c - Convert an OpenPGP key to our internal format.
* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2006, 2009,
* 2010 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "agent.h"
#include "i18n.h"
#include "cvt-openpgp.h"
/* Helper to pass data via the callback to do_unprotect. */
struct try_do_unprotect_arg_s
{
int is_v4;
int is_protected;
int pubkey_algo;
int protect_algo;
char *iv;
int ivlen;
int s2k_mode;
int s2k_algo;
byte *s2k_salt;
u32 s2k_count;
u16 desired_csum;
gcry_mpi_t *skey;
size_t skeysize;
int skeyidx;
gcry_sexp_t *r_key;
};
/* Compute the keygrip from the public key and store it at GRIP. */
static gpg_error_t
get_keygrip (int pubkey_algo, gcry_mpi_t *pkey, unsigned char *grip)
{
gpg_error_t err;
gcry_sexp_t s_pkey = NULL;
switch (pubkey_algo)
{
case GCRY_PK_DSA:
err = gcry_sexp_build (&s_pkey, NULL,
"(public-key(dsa(p%m)(q%m)(g%m)(y%m)))",
pkey[0], pkey[1], pkey[2], pkey[3]);
break;
case GCRY_PK_ELG:
case GCRY_PK_ELG_E:
err = gcry_sexp_build (&s_pkey, NULL,
"(public-key(elg(p%m)(g%m)(y%m)))",
pkey[0], pkey[1], pkey[2]);
break;
case GCRY_PK_RSA:
case GCRY_PK_RSA_E:
case GCRY_PK_RSA_S:
err = gcry_sexp_build (&s_pkey, NULL,
"(public-key(rsa(n%m)(e%m)))", pkey[0], pkey[1]);
break;
default:
err = gpg_error (GPG_ERR_PUBKEY_ALGO);
break;
}
if (!err && !gcry_pk_get_keygrip (s_pkey, grip))
err = gpg_error (GPG_ERR_INTERNAL);
gcry_sexp_release (s_pkey);
return err;
}
/* Convert a secret key given as algorithm id and an array of key
parameters into our s-expression based format. */
static gpg_error_t
convert_secret_key (gcry_sexp_t *r_key, int pubkey_algo, gcry_mpi_t *skey)
{
gpg_error_t err;
gcry_sexp_t s_skey = NULL;
*r_key = NULL;
switch (pubkey_algo)
{
case GCRY_PK_DSA:
err = gcry_sexp_build (&s_skey, NULL,
"(private-key(dsa(p%m)(q%m)(g%m)(y%m)(x%m)))",
skey[0], skey[1], skey[2], skey[3], skey[4]);
break;
case GCRY_PK_ELG:
case GCRY_PK_ELG_E:
err = gcry_sexp_build (&s_skey, NULL,
"(private-key(elg(p%m)(g%m)(y%m)(x%m)))",
skey[0], skey[1], skey[2], skey[3]);
break;
case GCRY_PK_RSA:
case GCRY_PK_RSA_E:
case GCRY_PK_RSA_S:
err = gcry_sexp_build (&s_skey, NULL,
"(private-key(rsa(n%m)(e%m)(d%m)(p%m)(q%m)(u%m)))",
skey[0], skey[1], skey[2], skey[3], skey[4],
skey[5]);
default:
err = gpg_error (GPG_ERR_PUBKEY_ALGO);
break;
}
if (!err)
*r_key = s_skey;
return err;
}
/* Hash the passphrase and set the key. */
static gpg_error_t
hash_passphrase_and_set_key (const char *passphrase,
gcry_cipher_hd_t hd, int protect_algo,
int s2k_mode, int s2k_algo,
byte *s2k_salt, u32 s2k_count)
{
gpg_error_t err;
unsigned char *key;
size_t keylen;
keylen = gcry_cipher_get_algo_keylen (protect_algo);
if (!keylen)
return gpg_error (GPG_ERR_INTERNAL);
key = xtrymalloc_secure (keylen);
if (!key)
return gpg_error_from_syserror ();
err = s2k_hash_passphrase (passphrase,
s2k_algo, s2k_mode, s2k_salt, s2k_count,
key, keylen);
if (!err)
err = gcry_cipher_setkey (hd, key, keylen);
xfree (key);
return err;
}
static u16
checksum (const unsigned char *p, unsigned int n)
{
u16 a;
for (a=0; n; n-- )
a += *p++;
return a;
}
/* Note that this function modified SKEY. SKEYSIZE is the allocated
size of the array including the NULL item; this is used for a
bounds check. On success a converted key is stored at R_KEY. */
static int
do_unprotect (const char *passphrase,
int pkt_version, int pubkey_algo, int is_protected,
gcry_mpi_t *skey, size_t skeysize,
int protect_algo, void *protect_iv, size_t protect_ivlen,
int s2k_mode, int s2k_algo, byte *s2k_salt, u32 s2k_count,
u16 desired_csum, gcry_sexp_t *r_key)
{
gpg_error_t err;
size_t npkey, nskey, skeylen;
gcry_cipher_hd_t cipher_hd = NULL;
u16 actual_csum;
size_t nbytes;
int i;
gcry_mpi_t tmpmpi;
*r_key = NULL;
/* Count the actual number of MPIs is in the array and set the
remainder to NULL for easier processing later on. */
for (skeylen = 0; skey[skeylen]; skeylen++)
;
for (i=skeylen; i < skeysize; i++)
skey[i] = NULL;
/* Check some args. */
if (s2k_mode == 1001)
{
/* Stub key. */
log_info (_("secret key parts are not available\n"));
return gpg_error (GPG_ERR_UNUSABLE_SECKEY);
}
if (gcry_pk_test_algo (pubkey_algo))
{
/* The algorithm numbers are Libgcrypt numbers but fortunately
the OpenPGP algorithm numbers map one-to-one to the Libgcrypt
numbers. */
log_info (_("public key algorithm %d (%s) is not supported\n"),
pubkey_algo, gcry_pk_algo_name (pubkey_algo));
return gpg_error (GPG_ERR_PUBKEY_ALGO);
}
/* Get properties of the public key algorithm and do some
consistency checks. Note that we need at least NPKEY+1 elements
in the SKEY array. */
if ( (err = gcry_pk_algo_info (pubkey_algo, GCRYCTL_GET_ALGO_NPKEY,
NULL, &npkey))
|| (err = gcry_pk_algo_info (pubkey_algo, GCRYCTL_GET_ALGO_NSKEY,
NULL, &nskey)))
return err;
if (!npkey || npkey >= nskey)
return gpg_error (GPG_ERR_INTERNAL);
if (skeylen <= npkey)
return gpg_error (GPG_ERR_MISSING_VALUE);
if (nskey+1 >= skeysize)
return gpg_error (GPG_ERR_BUFFER_TOO_SHORT);
/* Check whether SKEY is at all protected. If it is not protected
merely verify the checksum. */
if (!is_protected)
{
unsigned char *buffer;
actual_csum = 0;
for (i=npkey; i < nskey; i++)
{
if (!skey[i] || gcry_mpi_get_flag (skey[i], GCRYMPI_FLAG_OPAQUE))
return gpg_error (GPG_ERR_BAD_SECKEY);
err = gcry_mpi_print (GCRYMPI_FMT_PGP, NULL, 0, &nbytes, skey[i]);
if (!err)
{
buffer = (gcry_is_secure (skey[i])?
xtrymalloc_secure (nbytes) : xtrymalloc (nbytes));
if (!buffer)
return gpg_error_from_syserror ();
err = gcry_mpi_print (GCRYMPI_FMT_PGP, buffer, nbytes,
NULL, skey[i]);
if (!err)
actual_csum += checksum (buffer, nbytes);
xfree (buffer);
}
if (err)
return err;
}
if (actual_csum != desired_csum)
return gpg_error (GPG_ERR_CHECKSUM);
return 0;
}
if (gcry_cipher_test_algo (protect_algo))
{
/* The algorithm numbers are Libgcrypt numbers but fortunately
the OpenPGP algorithm numbers map one-to-one to the Libgcrypt
numbers. */
log_info (_("protection algorithm %d (%s) is not supported\n"),
protect_algo, gcry_cipher_algo_name (protect_algo));
return gpg_error (GPG_ERR_CIPHER_ALGO);
}
if (gcry_md_test_algo (s2k_algo))
{
log_info (_("protection hash algorithm %d (%s) is not supported\n"),
s2k_algo, gcry_md_algo_name (s2k_algo));
return gpg_error (GPG_ERR_DIGEST_ALGO);
}
err = gcry_cipher_open (&cipher_hd, protect_algo,
GCRY_CIPHER_MODE_CFB,
(GCRY_CIPHER_SECURE
| (protect_algo >= 100 ?
0 : GCRY_CIPHER_ENABLE_SYNC)));
if (err)
{
log_error ("failed to open cipher_algo %d: %s\n",
protect_algo, gpg_strerror (err));
return err;
}
err = hash_passphrase_and_set_key (passphrase, cipher_hd, protect_algo,
s2k_mode, s2k_algo, s2k_salt, s2k_count);
if (err)
{
gcry_cipher_close (cipher_hd);
return err;
}
gcry_cipher_setiv (cipher_hd, protect_iv, protect_ivlen);
actual_csum = 0;
if (pkt_version >= 4)
{
int ndata;
unsigned int ndatabits;
unsigned char *p, *data;
u16 csum_pgp7 = 0;
if (!gcry_mpi_get_flag (skey[npkey], GCRYMPI_FLAG_OPAQUE ))
{
gcry_cipher_close (cipher_hd);
return gpg_error (GPG_ERR_BAD_SECKEY);
}
p = gcry_mpi_get_opaque (skey[npkey], &ndatabits);
ndata = (ndatabits+7)/8;
if (ndata > 1)
csum_pgp7 = p[ndata-2] << 8 | p[ndata-1];
data = xtrymalloc_secure (ndata);
if (!data)
{
err = gpg_error_from_syserror ();
gcry_cipher_close (cipher_hd);
return err;
}
gcry_cipher_decrypt (cipher_hd, data, ndata, p, ndata);
p = data;
if (is_protected == 2)
{
/* This is the new SHA1 checksum method to detect tampering
with the key as used by the Klima/Rosa attack. */
desired_csum = 0;
actual_csum = 1; /* Default to bad checksum. */
if (ndata < 20)
log_error ("not enough bytes for SHA-1 checksum\n");
else
{
gcry_md_hd_t h;
if (gcry_md_open (&h, GCRY_MD_SHA1, 1))
BUG(); /* Algo not available. */
gcry_md_write (h, data, ndata - 20);
gcry_md_final (h);
if (!memcmp (gcry_md_read (h, GCRY_MD_SHA1), data+ndata-20, 20))
actual_csum = 0; /* Digest does match. */
gcry_md_close (h);
}
}
else
{
/* Old 16 bit checksum method. */
if (ndata < 2)
{
log_error ("not enough bytes for checksum\n");
desired_csum = 0;
actual_csum = 1; /* Mark checksum bad. */
}
else
{
desired_csum = (data[ndata-2] << 8 | data[ndata-1]);
actual_csum = checksum (data, ndata-2);
if (desired_csum != actual_csum)
{
/* This is a PGP 7.0.0 workaround */
desired_csum = csum_pgp7; /* Take the encrypted one. */
}
}
}
/* Better check it here. Otherwise the gcry_mpi_scan would fail
because the length may have an arbitrary value. */
if (desired_csum == actual_csum)
{
for (i=npkey; i < nskey; i++ )
{
if (gcry_mpi_scan (&tmpmpi, GCRYMPI_FMT_PGP, p, ndata, &nbytes))
{
/* Checksum was okay, but not correctly decrypted. */
desired_csum = 0;
actual_csum = 1; /* Mark checksum bad. */
break;
}
gcry_mpi_release (skey[i]);
skey[i] = tmpmpi;
ndata -= nbytes;
p += nbytes;
}
skey[i] = NULL;
skeylen = i;
assert (skeylen <= skeysize);
/* Note: at this point NDATA should be 2 for a simple
checksum or 20 for the sha1 digest. */
}
xfree(data);
}
else /* Packet version <= 3. */
{
unsigned char *buffer;
for (i = npkey; i < nskey; i++)
{
unsigned char *p;
size_t ndata;
unsigned int ndatabits;
if (!skey[i] || !gcry_mpi_get_flag (skey[i], GCRYMPI_FLAG_OPAQUE))
{
gcry_cipher_close (cipher_hd);
return gpg_error (GPG_ERR_BAD_SECKEY);
}
p = gcry_mpi_get_opaque (skey[i], &ndatabits);
ndata = (ndatabits+7)/8;
if (!(ndata >= 2) || !(ndata == ((p[0] << 8 | p[1]) + 7)/8 + 2))
{
gcry_cipher_close (cipher_hd);
return gpg_error (GPG_ERR_BAD_SECKEY);
}
buffer = xtrymalloc_secure (ndata);
if (!buffer)
{
err = gpg_error_from_syserror ();
gcry_cipher_close (cipher_hd);
return err;
}
gcry_cipher_sync (cipher_hd);
buffer[0] = p[0];
buffer[1] = p[1];
gcry_cipher_decrypt (cipher_hd, buffer+2, ndata-2, p+2, ndata-2);
actual_csum += checksum (buffer, ndata);
err = gcry_mpi_scan (&tmpmpi, GCRYMPI_FMT_PGP, buffer, ndata, &ndata);
xfree (buffer);
if (err)
{
/* Checksum was okay, but not correctly decrypted. */
desired_csum = 0;
actual_csum = 1; /* Mark checksum bad. */
break;
}
gcry_mpi_release (skey[i]);
skey[i] = tmpmpi;
}
}
gcry_cipher_close (cipher_hd);
/* Now let's see whether we have used the correct passphrase. */
if (actual_csum != desired_csum)
return gpg_error (GPG_ERR_BAD_PASSPHRASE);
if (nskey != skeylen)
err = gpg_error (GPG_ERR_BAD_SECKEY);
else
err = convert_secret_key (r_key, pubkey_algo, skey);
if (err)
return err;
/* The checksum may fail, thus we also check the key itself. */
err = gcry_pk_testkey (*r_key);
if (err)
{
gcry_sexp_release (*r_key);
*r_key = NULL;
return gpg_error (GPG_ERR_BAD_PASSPHRASE);
}
return 0;
}
/* Callback function to try the unprotection from the passpharse query
code. */
static int
try_do_unprotect_cb (struct pin_entry_info_s *pi)
{
gpg_error_t err;
struct try_do_unprotect_arg_s *arg = pi->check_cb_arg;
err = do_unprotect (pi->pin, arg->is_v4? 4:3,
arg->pubkey_algo, arg->is_protected,
arg->skey, arg->skeysize,
arg->protect_algo, arg->iv, arg->ivlen,
arg->s2k_mode, arg->s2k_algo,
arg->s2k_salt, arg->s2k_count,
arg->desired_csum, arg->r_key);
/* SKEY may be modified now, thus we need to re-compute SKEYIDX. */
for (arg->skeyidx = 0; (arg->skeyidx < arg->skeysize
&& arg->skey[arg->skeyidx]); arg->skeyidx++)
;
return err;
}
/* Convert an OpenPGP transfer key into our internal format. Before
asking for a passphrase we check whether the key already exists in
our key storage. S_PGP is the OpenPGP key in transfer format. On
success R_KEY will receive a canonical encoded S-expression with
the unprotected key in our internal format; the caller needs to
release that memory. The passphrase used to decrypt the OpenPGP
key will be returned at R_PASSPHRASE; the caller must release this
passphrase. The keygrip will be stored at the 20 byte buffer
pointed to by GRIP. On error NULL is stored at all return
arguments. */
gpg_error_t
convert_openpgp (ctrl_t ctrl, gcry_sexp_t s_pgp,
unsigned char *grip, const char *prompt,
unsigned char **r_key, char **r_passphrase)
{
gpg_error_t err;
gcry_sexp_t top_list;
gcry_sexp_t list = NULL;
const char *value;
size_t valuelen;
char *string;
int idx;
int is_v4, is_protected;
int pubkey_algo;
int protect_algo = 0;
char iv[16];
int ivlen = 0;
int s2k_mode = 0;
int s2k_algo = 0;
byte s2k_salt[8];
u32 s2k_count = 0;
size_t npkey, nskey;
gcry_mpi_t skey[10]; /* We support up to 9 parameters. */
u16 desired_csum;
int skeyidx = 0;
gcry_sexp_t s_skey;
struct pin_entry_info_s *pi;
struct try_do_unprotect_arg_s pi_arg;
*r_key = NULL;
*r_passphrase = NULL;
top_list = gcry_sexp_find_token (s_pgp, "openpgp-private-key", 0);
if (!top_list)
goto bad_seckey;
list = gcry_sexp_find_token (top_list, "version", 0);
if (!list)
goto bad_seckey;
value = gcry_sexp_nth_data (list, 1, &valuelen);
if (!value || valuelen != 1 || !(value[0] == '3' || value[0] == '4'))
goto bad_seckey;
is_v4 = (value[0] == '4');
gcry_sexp_release (list);
list = gcry_sexp_find_token (top_list, "protection", 0);
if (!list)
goto bad_seckey;
value = gcry_sexp_nth_data (list, 1, &valuelen);
if (!value)
goto bad_seckey;
if (valuelen == 4 && !memcmp (value, "sha1", 4))
is_protected = 2;
else if (valuelen == 3 && !memcmp (value, "sum", 3))
is_protected = 1;
else if (valuelen == 4 && !memcmp (value, "none", 4))
is_protected = 0;
else
goto bad_seckey;
if (is_protected)
{
string = gcry_sexp_nth_string (list, 2);
if (!string)
goto bad_seckey;
protect_algo = gcry_cipher_map_name (string);
if (!protect_algo && !!strcmp (string, "IDEA"))
protect_algo = GCRY_CIPHER_IDEA;
xfree (string);
value = gcry_sexp_nth_data (list, 3, &valuelen);
if (!value || !valuelen || valuelen > sizeof iv)
goto bad_seckey;
memcpy (iv, value, valuelen);
ivlen = valuelen;
string = gcry_sexp_nth_string (list, 4);
if (!string)
goto bad_seckey;
s2k_mode = strtol (string, NULL, 10);
xfree (string);
string = gcry_sexp_nth_string (list, 5);
if (!string)
goto bad_seckey;
s2k_algo = gcry_md_map_name (string);
xfree (string);
value = gcry_sexp_nth_data (list, 6, &valuelen);
if (!value || !valuelen || valuelen > sizeof s2k_salt)
goto bad_seckey;
memcpy (s2k_salt, value, valuelen);
string = gcry_sexp_nth_string (list, 7);
if (!string)
goto bad_seckey;
s2k_count = strtoul (string, NULL, 10);
xfree (string);
}
gcry_sexp_release (list);
list = gcry_sexp_find_token (top_list, "algo", 0);
if (!list)
goto bad_seckey;
string = gcry_sexp_nth_string (list, 1);
if (!string)
goto bad_seckey;
pubkey_algo = gcry_pk_map_name (string);
xfree (string);
if (gcry_pk_algo_info (pubkey_algo, GCRYCTL_GET_ALGO_NPKEY, NULL, &npkey)
|| gcry_pk_algo_info (pubkey_algo, GCRYCTL_GET_ALGO_NSKEY, NULL, &nskey)
|| !npkey || npkey >= nskey)
goto bad_seckey;
gcry_sexp_release (list);
list = gcry_sexp_find_token (top_list, "skey", 0);
if (!list)
goto bad_seckey;
for (idx=0;;)
{
int is_enc;
value = gcry_sexp_nth_data (list, ++idx, &valuelen);
if (!value && skeyidx >= npkey)
break; /* Ready. */
/* Check for too many parameters. Note that depending on the
protection mode and version number we may see less than NSKEY
(but at least NPKEY+1) parameters. */
if (idx >= 2*nskey)
goto bad_seckey;
if (skeyidx >= DIM (skey)-1)
goto bad_seckey;
if (!value || valuelen != 1 || !(value[0] == '_' || value[0] == 'e'))
goto bad_seckey;
is_enc = (value[0] == 'e');
value = gcry_sexp_nth_data (list, ++idx, &valuelen);
if (!value || !valuelen)
goto bad_seckey;
if (is_enc)
{
void *p = xtrymalloc (valuelen);
if (!p)
goto outofmem;
memcpy (p, value, valuelen);
skey[skeyidx] = gcry_mpi_set_opaque (NULL, p, valuelen*8);
if (!skey[skeyidx])
goto outofmem;
}
else
{
if (gcry_mpi_scan (skey + skeyidx, GCRYMPI_FMT_STD,
value, valuelen, NULL))
goto bad_seckey;
}
skeyidx++;
}
skey[skeyidx++] = NULL;
gcry_sexp_release (list);
list = gcry_sexp_find_token (top_list, "csum", 0);
if (list)
{
string = gcry_sexp_nth_string (list, 1);
if (!string)
goto bad_seckey;
desired_csum = strtoul (string, NULL, 10);
xfree (string);
}
else
desired_csum = 0;
gcry_sexp_release (list); list = NULL;
gcry_sexp_release (top_list); top_list = NULL;
/* log_debug ("XXX is_v4=%d\n", is_v4); */
/* log_debug ("XXX pubkey_algo=%d\n", pubkey_algo); */
/* log_debug ("XXX is_protected=%d\n", is_protected); */
/* log_debug ("XXX protect_algo=%d\n", protect_algo); */
/* log_printhex ("XXX iv", iv, ivlen); */
/* log_debug ("XXX ivlen=%d\n", ivlen); */
/* log_debug ("XXX s2k_mode=%d\n", s2k_mode); */
/* log_debug ("XXX s2k_algo=%d\n", s2k_algo); */
/* log_printhex ("XXX s2k_salt", s2k_salt, sizeof s2k_salt); */
/* log_debug ("XXX s2k_count=%lu\n", (unsigned long)s2k_count); */
/* for (idx=0; skey[idx]; idx++) */
/* { */
/* int is_enc = gcry_mpi_get_flag (skey[idx], GCRYMPI_FLAG_OPAQUE); */
/* log_info ("XXX skey[%d]%s:", idx, is_enc? " (enc)":""); */
/* if (is_enc) */
/* { */
/* void *p; */
/* unsigned int nbits; */
/* p = gcry_mpi_get_opaque (skey[idx], &nbits); */
/* log_printhex (NULL, p, (nbits+7)/8); */
/* } */
/* else */
/* gcry_mpi_dump (skey[idx]); */
/* log_printf ("\n"); */
/* } */
err = get_keygrip (pubkey_algo, skey, grip);
if (err)
goto leave;
if (!agent_key_available (grip))
{
err = gpg_error (GPG_ERR_EEXIST);
goto leave;
}
pi = xtrycalloc_secure (1, sizeof (*pi) + 100);
if (!pi)
return gpg_error_from_syserror ();
pi->max_length = 100;
pi->min_digits = 0; /* We want a real passphrase. */
pi->max_digits = 16;
pi->max_tries = 3;
pi->check_cb = try_do_unprotect_cb;
pi->check_cb_arg = &pi_arg;
pi_arg.is_v4 = is_v4;
pi_arg.is_protected = is_protected;
pi_arg.pubkey_algo = pubkey_algo;
pi_arg.protect_algo = protect_algo;
pi_arg.iv = iv;
pi_arg.ivlen = ivlen;
pi_arg.s2k_mode = s2k_mode;
pi_arg.s2k_algo = s2k_algo;
pi_arg.s2k_salt = s2k_salt;
pi_arg.s2k_count = s2k_count;
pi_arg.desired_csum = desired_csum;
pi_arg.skey = skey;
pi_arg.skeysize = DIM (skey);
pi_arg.skeyidx = skeyidx;
pi_arg.r_key = &s_skey;
err = agent_askpin (ctrl, prompt, NULL, NULL, pi);
skeyidx = pi_arg.skeyidx;
if (!err)
{
*r_passphrase = xtrystrdup (pi->pin);
if (!*r_passphrase)
err = gpg_error_from_syserror ();
}
xfree (pi);
if (err)
goto leave;
/* Save some memory and get rid of the SKEY array now. */
for (idx=0; idx < skeyidx; idx++)
gcry_mpi_release (skey[idx]);
skeyidx = 0;
/* Note that the padding is not required - we use it only because
that function allows us to created the result in secure memory. */
err = make_canon_sexp_pad (s_skey, 1, r_key, NULL);
gcry_sexp_release (s_skey);
leave:
gcry_sexp_release (list);
gcry_sexp_release (top_list);
for (idx=0; idx < skeyidx; idx++)
gcry_mpi_release (skey[idx]);
if (err)
{
xfree (*r_passphrase);
*r_passphrase = NULL;
}
return err;
bad_seckey:
err = gpg_error (GPG_ERR_BAD_SECKEY);
goto leave;
outofmem:
err = gpg_error (GPG_ERR_ENOMEM);
goto leave;
}

27
agent/cvt-openpgp.h Normal file
View file

@ -0,0 +1,27 @@
/* cvt-openpgp.h - Convert an OpenPGP key to our internal format.
* Copyright (C) 2010 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/>.
*/
#ifndef GNUPG_AGENT_CVT_OPENPGP_H
#define GNUPG_AGENT_CVT_OPENPGP_H
gpg_error_t convert_openpgp (ctrl_t ctrl, gcry_sexp_t s_pgp,
unsigned char *grip, const char *prompt,
unsigned char **r_key, char **r_passphrase);
#endif /*GNUPG_AGENT_CVT_OPENPGP_H*/

10
agent/findkey.c
View file

@ -702,7 +702,8 @@ key_parms_from_sexp (gcry_sexp_t s_key, gcry_sexp_t *r_list,
}
/* Return true if S_KEY is a DSA style key. */
/* Return the public key algorithm number if S_KEY is a DSA style key.
If it is not a DSA style key, return 0. */
int
agent_is_dsa_key (gcry_sexp_t s_key)
{
@ -714,7 +715,12 @@ agent_is_dsa_key (gcry_sexp_t s_key)
if (key_parms_from_sexp (s_key, NULL, algoname, sizeof algoname, NULL, 0))
return 0; /* Error - assume it is not an DSA key. */
return (!strcmp (algoname, "dsa") || !strcmp (algoname, "ecdsa"));
if (!strcmp (algoname, "dsa"))
return GCRY_PK_DSA;
else if (!strcmp (algoname, "ecdsa"))
return GCRY_PK_ECDSA;
else
return 0;
}

27
agent/keyformat.txt
View file

@ -159,7 +159,34 @@ second list with the information has this layout:
More items may be added to the list.
OpenPGP Private Key Transfer Format
===================================
This format is used to transfer keys between gpg and gpg-agent.
(openpgp-private-key
(version V)
(protection PROTTYPE PROTALGO IV S2KMODE S2KHASH S2KSALT S2KCOUNT)
(algo PUBKEYALGO)
(skey CSUM c P1 c P2 c P3 ... e PN))
* V is the packet version number (3 or 4).
* PUBKEYALGO is a Libgcrypt algo name
* CSUM is the 16 bit checksum as defined by OpenPGP.
* P1 .. PN are the parameters; the public parameters are never encrypted
the secrect key parameters are encrypted if the "protection" list is
given. To make this more explicit each parameter is preceded by a
flag "_" for cleartext or "e" for encrypted text.
* If PROTTYPE is "sha1" the new style SHA1 checksum is used if it is "sum"
the old 16 bit checksum is used and if it is "none" no protection at
all is used.
* PROTALGO is a Libgcrypt style cipher algorithm name
* IV is the initialization verctor.
* S2KMODE is the value from RFC-4880.
* S2KHASH is a a libgcrypt style hash algorithm identifier.
* S2KSALT is the 8 byte salt
* S2KCOUNT is the count value from RFC-4880.

26
agent/pksign.c
View file

@ -164,10 +164,22 @@ do_encode_dsa (const byte * md, size_t mdlen, int dsaalgo, gcry_sexp_t pkey,
if (mdlen > qbits/8)
mdlen = qbits/8;
/* Create the S-expression. */
err = gcry_sexp_build (&hash, NULL,
"(data (flags raw) (value %b))",
(int)mdlen, md);
/* Create the S-expression. We need to convert to an MPI first
because we want an unsigned integer. Using %b directly is not
possible because libgcrypt assumes an mpi and uses
GCRYMPI_FMT_STD for parsing and thus possible yielding a negative
value. */
{
gcry_mpi_t mpi;
err = gcry_mpi_scan (&mpi, GCRYMPI_FMT_USG, md, mdlen, NULL);
if (!err)
{
err = gcry_sexp_build (&hash, NULL,
"(data (flags raw) (value %m))", mpi);
gcry_mpi_release (mpi);
}
}
if (!err)
*r_hash = hash;
return err;
@ -304,8 +316,10 @@ agent_pksign_do (ctrl_t ctrl, const char *desc_text,
if (DBG_CRYPTO)
{
log_debug ("skey: ");
log_debug ("skey:\n");
gcry_sexp_dump (s_skey);
log_debug ("hash:\n");
gcry_sexp_dump (s_hash);
}
/* sign */
@ -319,7 +333,7 @@ agent_pksign_do (ctrl_t ctrl, const char *desc_text,
if (DBG_CRYPTO)
{
log_debug ("result: ");
log_debug ("result:\n");
gcry_sexp_dump (s_sig);
}
}

15
agent/protect.c
View file

@ -73,6 +73,8 @@ hash_passphrase (const char *passphrase, int hashalgo,
const unsigned char *s2ksalt, unsigned long s2kcount,
unsigned char *key, size_t keylen);
/* Get the process time and store it in DATA. */
static void
calibrate_get_time (struct calibrate_time_s *data)
@ -1076,6 +1078,19 @@ hash_passphrase (const char *passphrase, int hashalgo,
}
gpg_error_t
s2k_hash_passphrase (const char *passphrase, int hashalgo,
int s2kmode,
const unsigned char *s2ksalt,
unsigned int s2kcount,
unsigned char *key, size_t keylen)
{
return hash_passphrase (passphrase, hashalgo, s2kmode, s2ksalt,
(16ul + (s2kcount & 15)) << ((s2kcount >> 4) + 6),
key, keylen);
}
/* Create an canonical encoded S-expression with the shadow info from