mirror of
git://git.gnupg.org/gnupg.git
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1117 lines
33 KiB
C
1117 lines
33 KiB
C
/* cvt-openpgp.c - Convert an OpenPGP key to our internal format.
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* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2006, 2009,
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* 2010 Free Software Foundation, Inc.
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*
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* This file is part of GnuPG.
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*
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* GnuPG is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 3 of the License, or
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* (at your option) any later version.
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*
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* GnuPG is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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#include <config.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <assert.h>
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#include "agent.h"
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#include "i18n.h"
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#include "cvt-openpgp.h"
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/* Helper to pass data via the callback to do_unprotect. */
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struct try_do_unprotect_arg_s
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{
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int is_v4;
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int is_protected;
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int pubkey_algo;
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int protect_algo;
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char *iv;
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int ivlen;
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int s2k_mode;
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int s2k_algo;
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byte *s2k_salt;
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u32 s2k_count;
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u16 desired_csum;
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gcry_mpi_t *skey;
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size_t skeysize;
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int skeyidx;
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gcry_sexp_t *r_key;
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};
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/* Compute the keygrip from the public key and store it at GRIP. */
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static gpg_error_t
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get_keygrip (int pubkey_algo, gcry_mpi_t *pkey, unsigned char *grip)
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{
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gpg_error_t err;
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gcry_sexp_t s_pkey = NULL;
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switch (pubkey_algo)
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{
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case GCRY_PK_DSA:
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err = gcry_sexp_build (&s_pkey, NULL,
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"(public-key(dsa(p%m)(q%m)(g%m)(y%m)))",
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pkey[0], pkey[1], pkey[2], pkey[3]);
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break;
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case GCRY_PK_ELG:
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case GCRY_PK_ELG_E:
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err = gcry_sexp_build (&s_pkey, NULL,
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"(public-key(elg(p%m)(g%m)(y%m)))",
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pkey[0], pkey[1], pkey[2]);
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break;
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case GCRY_PK_RSA:
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case GCRY_PK_RSA_E:
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case GCRY_PK_RSA_S:
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err = gcry_sexp_build (&s_pkey, NULL,
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"(public-key(rsa(n%m)(e%m)))", pkey[0], pkey[1]);
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break;
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case GCRY_PK_ECDSA:
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case GCRY_PK_ECDH:
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err = gcry_sexp_build (&s_pkey, NULL,
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"(public-key(ecc(p%m)(a%m)(b%m)(g%m)(n%m)(q%m)))",
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pkey[0], pkey[1], pkey[2], pkey[3], pkey[4],
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pkey[5]);
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break;
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default:
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err = gpg_error (GPG_ERR_PUBKEY_ALGO);
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break;
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}
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if (!err && !gcry_pk_get_keygrip (s_pkey, grip))
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err = gpg_error (GPG_ERR_INTERNAL);
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gcry_sexp_release (s_pkey);
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return err;
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}
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/* Convert a secret key given as algorithm id and an array of key
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parameters into our s-expression based format. Note that
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PUBKEY_ALGO has an gcrypt algorithm number. */
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static gpg_error_t
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convert_secret_key (gcry_sexp_t *r_key, int pubkey_algo, gcry_mpi_t *skey)
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{
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gpg_error_t err;
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gcry_sexp_t s_skey = NULL;
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*r_key = NULL;
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switch (pubkey_algo)
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{
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case GCRY_PK_DSA:
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err = gcry_sexp_build (&s_skey, NULL,
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"(private-key(dsa(p%m)(q%m)(g%m)(y%m)(x%m)))",
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skey[0], skey[1], skey[2], skey[3], skey[4]);
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break;
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case GCRY_PK_ELG:
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case GCRY_PK_ELG_E:
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err = gcry_sexp_build (&s_skey, NULL,
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"(private-key(elg(p%m)(g%m)(y%m)(x%m)))",
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skey[0], skey[1], skey[2], skey[3]);
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break;
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case GCRY_PK_RSA:
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case GCRY_PK_RSA_E:
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case GCRY_PK_RSA_S:
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err = gcry_sexp_build (&s_skey, NULL,
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"(private-key(rsa(n%m)(e%m)(d%m)(p%m)(q%m)(u%m)))",
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skey[0], skey[1], skey[2], skey[3], skey[4],
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skey[5]);
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break;
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case GCRY_PK_ECDSA:
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case GCRY_PK_ECDH:
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/* Although our code would work with "ecc" we explicitly use
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"ecdh" or "ecdsa" to implicitly set the key capabilities. */
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err = gcry_sexp_build (&s_skey, NULL,
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"(private-key(%s(p%m)(a%m)(b%m)(g%m)(n%m)(q%m)"
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"(d%m)))",
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pubkey_algo == GCRY_PK_ECDSA?"ecdsa":"ecdh",
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skey[0], skey[1], skey[2], skey[3], skey[4],
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skey[5], skey[6]);
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break;
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default:
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err = gpg_error (GPG_ERR_PUBKEY_ALGO);
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break;
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}
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if (!err)
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*r_key = s_skey;
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return err;
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}
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/* Hash the passphrase and set the key. */
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static gpg_error_t
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hash_passphrase_and_set_key (const char *passphrase,
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gcry_cipher_hd_t hd, int protect_algo,
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int s2k_mode, int s2k_algo,
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byte *s2k_salt, u32 s2k_count)
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{
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gpg_error_t err;
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unsigned char *key;
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size_t keylen;
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keylen = gcry_cipher_get_algo_keylen (protect_algo);
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if (!keylen)
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return gpg_error (GPG_ERR_INTERNAL);
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key = xtrymalloc_secure (keylen);
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if (!key)
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return gpg_error_from_syserror ();
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err = s2k_hash_passphrase (passphrase,
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s2k_algo, s2k_mode, s2k_salt, s2k_count,
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key, keylen);
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if (!err)
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err = gcry_cipher_setkey (hd, key, keylen);
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xfree (key);
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return err;
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}
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static u16
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checksum (const unsigned char *p, unsigned int n)
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{
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u16 a;
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for (a=0; n; n-- )
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a += *p++;
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return a;
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}
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/* Note that this function modified SKEY. SKEYSIZE is the allocated
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size of the array including the NULL item; this is used for a
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bounds check. On success a converted key is stored at R_KEY. */
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static int
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do_unprotect (const char *passphrase,
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int pkt_version, int pubkey_algo, int is_protected,
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gcry_mpi_t *skey, size_t skeysize,
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int protect_algo, void *protect_iv, size_t protect_ivlen,
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int s2k_mode, int s2k_algo, byte *s2k_salt, u32 s2k_count,
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u16 desired_csum, gcry_sexp_t *r_key)
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{
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gpg_error_t err;
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size_t npkey, nskey, skeylen;
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gcry_cipher_hd_t cipher_hd = NULL;
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u16 actual_csum;
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size_t nbytes;
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int i;
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gcry_mpi_t tmpmpi;
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*r_key = NULL;
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/* Unfortunately, the OpenPGP PK algorithm numbers need to be
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re-mapped for Libgcrypt. */
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pubkey_algo = map_pk_openpgp_to_gcry (pubkey_algo);
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/* Count the actual number of MPIs is in the array and set the
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remainder to NULL for easier processing later on. */
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for (skeylen = 0; skey[skeylen]; skeylen++)
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;
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for (i=skeylen; i < skeysize; i++)
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skey[i] = NULL;
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/* Check some args. */
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if (s2k_mode == 1001)
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{
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/* Stub key. */
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log_info (_("secret key parts are not available\n"));
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return gpg_error (GPG_ERR_UNUSABLE_SECKEY);
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}
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if (gcry_pk_test_algo (pubkey_algo))
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{
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log_info (_("public key algorithm %d (%s) is not supported\n"),
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pubkey_algo, gcry_pk_algo_name (pubkey_algo));
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return gpg_error (GPG_ERR_PUBKEY_ALGO);
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}
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/* Get properties of the public key algorithm and do some
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consistency checks. Note that we need at least NPKEY+1 elements
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in the SKEY array. */
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if ( (err = gcry_pk_algo_info (pubkey_algo, GCRYCTL_GET_ALGO_NPKEY,
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NULL, &npkey))
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|| (err = gcry_pk_algo_info (pubkey_algo, GCRYCTL_GET_ALGO_NSKEY,
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NULL, &nskey)))
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return err;
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if (!npkey || npkey >= nskey)
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return gpg_error (GPG_ERR_INTERNAL);
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if (skeylen <= npkey)
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return gpg_error (GPG_ERR_MISSING_VALUE);
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if (nskey+1 >= skeysize)
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return gpg_error (GPG_ERR_BUFFER_TOO_SHORT);
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/* Check whether SKEY is at all protected. If it is not protected
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merely verify the checksum. */
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if (!is_protected)
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{
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unsigned char *buffer;
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actual_csum = 0;
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for (i=npkey; i < nskey; i++)
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{
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if (!skey[i] || gcry_mpi_get_flag (skey[i], GCRYMPI_FLAG_OPAQUE))
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return gpg_error (GPG_ERR_BAD_SECKEY);
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err = gcry_mpi_print (GCRYMPI_FMT_PGP, NULL, 0, &nbytes, skey[i]);
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if (!err)
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{
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buffer = (gcry_is_secure (skey[i])?
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xtrymalloc_secure (nbytes) : xtrymalloc (nbytes));
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if (!buffer)
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return gpg_error_from_syserror ();
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err = gcry_mpi_print (GCRYMPI_FMT_PGP, buffer, nbytes,
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NULL, skey[i]);
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if (!err)
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actual_csum += checksum (buffer, nbytes);
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xfree (buffer);
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}
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if (err)
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return err;
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}
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if (actual_csum != desired_csum)
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return gpg_error (GPG_ERR_CHECKSUM);
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return 0;
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}
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if (gcry_cipher_test_algo (protect_algo))
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{
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/* The algorithm numbers are Libgcrypt numbers but fortunately
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the OpenPGP algorithm numbers map one-to-one to the Libgcrypt
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numbers. */
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log_info (_("protection algorithm %d (%s) is not supported\n"),
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protect_algo, gnupg_cipher_algo_name (protect_algo));
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return gpg_error (GPG_ERR_CIPHER_ALGO);
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}
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if (gcry_md_test_algo (s2k_algo))
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{
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log_info (_("protection hash algorithm %d (%s) is not supported\n"),
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s2k_algo, gcry_md_algo_name (s2k_algo));
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return gpg_error (GPG_ERR_DIGEST_ALGO);
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}
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err = gcry_cipher_open (&cipher_hd, protect_algo,
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GCRY_CIPHER_MODE_CFB,
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(GCRY_CIPHER_SECURE
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| (protect_algo >= 100 ?
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0 : GCRY_CIPHER_ENABLE_SYNC)));
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if (err)
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{
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log_error ("failed to open cipher_algo %d: %s\n",
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protect_algo, gpg_strerror (err));
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return err;
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}
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err = hash_passphrase_and_set_key (passphrase, cipher_hd, protect_algo,
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s2k_mode, s2k_algo, s2k_salt, s2k_count);
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if (err)
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{
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gcry_cipher_close (cipher_hd);
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return err;
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}
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gcry_cipher_setiv (cipher_hd, protect_iv, protect_ivlen);
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actual_csum = 0;
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if (pkt_version >= 4)
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{
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int ndata;
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unsigned int ndatabits;
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unsigned char *p, *data;
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u16 csum_pgp7 = 0;
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if (!gcry_mpi_get_flag (skey[npkey], GCRYMPI_FLAG_OPAQUE ))
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{
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gcry_cipher_close (cipher_hd);
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return gpg_error (GPG_ERR_BAD_SECKEY);
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}
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p = gcry_mpi_get_opaque (skey[npkey], &ndatabits);
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ndata = (ndatabits+7)/8;
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if (ndata > 1)
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csum_pgp7 = p[ndata-2] << 8 | p[ndata-1];
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data = xtrymalloc_secure (ndata);
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if (!data)
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{
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err = gpg_error_from_syserror ();
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gcry_cipher_close (cipher_hd);
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return err;
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}
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gcry_cipher_decrypt (cipher_hd, data, ndata, p, ndata);
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p = data;
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if (is_protected == 2)
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{
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/* This is the new SHA1 checksum method to detect tampering
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with the key as used by the Klima/Rosa attack. */
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desired_csum = 0;
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actual_csum = 1; /* Default to bad checksum. */
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if (ndata < 20)
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log_error ("not enough bytes for SHA-1 checksum\n");
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else
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{
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gcry_md_hd_t h;
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if (gcry_md_open (&h, GCRY_MD_SHA1, 1))
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BUG(); /* Algo not available. */
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gcry_md_write (h, data, ndata - 20);
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gcry_md_final (h);
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if (!memcmp (gcry_md_read (h, GCRY_MD_SHA1), data+ndata-20, 20))
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actual_csum = 0; /* Digest does match. */
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gcry_md_close (h);
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}
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}
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else
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{
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/* Old 16 bit checksum method. */
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||
if (ndata < 2)
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{
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log_error ("not enough bytes for checksum\n");
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||
desired_csum = 0;
|
||
actual_csum = 1; /* Mark checksum bad. */
|
||
}
|
||
else
|
||
{
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||
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. If
|
||
CACHE_NONCE is given the passphrase will be looked up in the cache.
|
||
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_from_openpgp (ctrl_t ctrl, gcry_sexp_t s_pgp,
|
||
unsigned char *grip, const char *prompt,
|
||
const char *cache_nonce,
|
||
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 = gpg_error (GPG_ERR_BAD_PASSPHRASE);
|
||
if (cache_nonce)
|
||
{
|
||
char *cache_value;
|
||
|
||
cache_value = agent_get_cache (cache_nonce, CACHE_MODE_NONCE);
|
||
if (cache_value)
|
||
{
|
||
if (strlen (cache_value) < pi->max_length)
|
||
strcpy (pi->pin, cache_value);
|
||
xfree (cache_value);
|
||
}
|
||
if (*pi->pin)
|
||
err = try_do_unprotect_cb (pi);
|
||
}
|
||
if (gpg_err_code (err) == GPG_ERR_BAD_PASSPHRASE)
|
||
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;
|
||
|
||
}
|
||
|
||
|
||
|
||
static gpg_error_t
|
||
key_from_sexp (gcry_sexp_t sexp, const char *elems, gcry_mpi_t *array)
|
||
{
|
||
gpg_error_t err = 0;
|
||
gcry_sexp_t l2;
|
||
int idx;
|
||
|
||
for (idx=0; *elems; elems++, idx++)
|
||
{
|
||
l2 = gcry_sexp_find_token (sexp, elems, 1);
|
||
if (!l2)
|
||
{
|
||
err = gpg_error (GPG_ERR_NO_OBJ); /* Required parameter not found. */
|
||
goto leave;
|
||
}
|
||
array[idx] = gcry_sexp_nth_mpi (l2, 1, GCRYMPI_FMT_USG);
|
||
gcry_sexp_release (l2);
|
||
if (!array[idx])
|
||
{
|
||
err = gpg_error (GPG_ERR_INV_OBJ); /* Required parameter invalid. */
|
||
goto leave;
|
||
}
|
||
}
|
||
|
||
leave:
|
||
if (err)
|
||
{
|
||
int i;
|
||
|
||
for (i=0; i < idx; i++)
|
||
{
|
||
gcry_mpi_release (array[i]);
|
||
array[i] = NULL;
|
||
}
|
||
}
|
||
return err;
|
||
}
|
||
|
||
|
||
/* Given an ARRAY of mpis with the key parameters, protect the secret
|
||
parameters in that array and replace them by one opaque encoded
|
||
mpi. NPKEY is the number of public key parameters and NSKEY is
|
||
the number of secret key parameters (including the public ones).
|
||
On success the array will have NPKEY+1 elements. */
|
||
static gpg_error_t
|
||
apply_protection (gcry_mpi_t *array, int npkey, int nskey,
|
||
const char *passphrase,
|
||
int protect_algo, void *protect_iv, size_t protect_ivlen,
|
||
int s2k_mode, int s2k_algo, byte *s2k_salt, u32 s2k_count)
|
||
{
|
||
gpg_error_t err;
|
||
int i, j;
|
||
gcry_cipher_hd_t cipherhd;
|
||
unsigned char *bufarr[10];
|
||
size_t narr[10];
|
||
unsigned int nbits[10];
|
||
int ndata;
|
||
unsigned char *p, *data;
|
||
|
||
assert (npkey < nskey);
|
||
assert (nskey < DIM (bufarr));
|
||
|
||
/* Collect only the secret key parameters into BUFARR et al and
|
||
compute the required size of the data buffer. */
|
||
ndata = 20; /* Space for the SHA-1 checksum. */
|
||
for (i = npkey, j = 0; i < nskey; i++, j++ )
|
||
{
|
||
err = gcry_mpi_aprint (GCRYMPI_FMT_USG, bufarr+j, narr+j, array[i]);
|
||
if (err)
|
||
{
|
||
err = gpg_error_from_syserror ();
|
||
for (i = 0; i < j; i++)
|
||
xfree (bufarr[i]);
|
||
return err;
|
||
}
|
||
nbits[j] = gcry_mpi_get_nbits (array[i]);
|
||
ndata += 2 + narr[j];
|
||
}
|
||
|
||
/* Allocate data buffer and stuff it with the secret key parameters. */
|
||
data = xtrymalloc_secure (ndata);
|
||
if (!data)
|
||
{
|
||
err = gpg_error_from_syserror ();
|
||
for (i = 0; i < (nskey-npkey); i++ )
|
||
xfree (bufarr[i]);
|
||
return err;
|
||
}
|
||
p = data;
|
||
for (i = 0; i < (nskey-npkey); i++ )
|
||
{
|
||
*p++ = nbits[i] >> 8 ;
|
||
*p++ = nbits[i];
|
||
memcpy (p, bufarr[i], narr[i]);
|
||
p += narr[i];
|
||
xfree (bufarr[i]);
|
||
bufarr[i] = NULL;
|
||
}
|
||
assert (p == data + ndata - 20);
|
||
|
||
/* Append a hash of the secret key parameters. */
|
||
gcry_md_hash_buffer (GCRY_MD_SHA1, p, data, ndata - 20);
|
||
|
||
/* Encrypt it. */
|
||
err = gcry_cipher_open (&cipherhd, protect_algo,
|
||
GCRY_CIPHER_MODE_CFB, GCRY_CIPHER_SECURE);
|
||
if (!err)
|
||
err = hash_passphrase_and_set_key (passphrase, cipherhd, protect_algo,
|
||
s2k_mode, s2k_algo, s2k_salt, s2k_count);
|
||
if (!err)
|
||
err = gcry_cipher_setiv (cipherhd, protect_iv, protect_ivlen);
|
||
if (!err)
|
||
err = gcry_cipher_encrypt (cipherhd, data, ndata, NULL, 0);
|
||
gcry_cipher_close (cipherhd);
|
||
if (err)
|
||
{
|
||
xfree (data);
|
||
return err;
|
||
}
|
||
|
||
/* Replace the secret key parameters in the array by one opaque value. */
|
||
for (i = npkey; i < nskey; i++ )
|
||
{
|
||
gcry_mpi_release (array[i]);
|
||
array[i] = NULL;
|
||
}
|
||
array[npkey] = gcry_mpi_set_opaque (NULL, data, ndata*8);
|
||
return 0;
|
||
}
|
||
|
||
|
||
/* Convert our key S_KEY into an OpenPGP key transfer format. On
|
||
success a canonical encoded S-expression is stored at R_TRANSFERKEY
|
||
and its length at R_TRANSFERKEYLEN; this S-expression is also
|
||
padded to a multiple of 64 bits. */
|
||
gpg_error_t
|
||
convert_to_openpgp (ctrl_t ctrl, gcry_sexp_t s_key, const char *passphrase,
|
||
unsigned char **r_transferkey, size_t *r_transferkeylen)
|
||
{
|
||
gpg_error_t err;
|
||
gcry_sexp_t list, l2;
|
||
char *name;
|
||
int algo;
|
||
const char *algoname;
|
||
const char *elems;
|
||
int npkey, nskey;
|
||
gcry_mpi_t array[10];
|
||
char protect_iv[16];
|
||
char salt[8];
|
||
unsigned long s2k_count;
|
||
int i, j;
|
||
|
||
(void)ctrl;
|
||
|
||
*r_transferkey = NULL;
|
||
|
||
for (i=0; i < DIM (array); i++)
|
||
array[i] = NULL;
|
||
|
||
list = gcry_sexp_find_token (s_key, "private-key", 0);
|
||
if (!list)
|
||
return gpg_error (GPG_ERR_NO_OBJ); /* Does not contain a key object. */
|
||
l2 = gcry_sexp_cadr (list);
|
||
gcry_sexp_release (list);
|
||
list = l2;
|
||
name = gcry_sexp_nth_string (list, 0);
|
||
if (!name)
|
||
{
|
||
gcry_sexp_release (list);
|
||
return gpg_error (GPG_ERR_INV_OBJ); /* Invalid structure of object. */
|
||
}
|
||
|
||
algo = gcry_pk_map_name (name);
|
||
xfree (name);
|
||
|
||
switch (algo)
|
||
{
|
||
case GCRY_PK_RSA: algoname = "rsa"; npkey = 2; elems = "nedpqu"; break;
|
||
case GCRY_PK_ELG: algoname = "elg"; npkey = 3; elems = "pgyx"; break;
|
||
case GCRY_PK_ELG_E: algoname = "elg"; npkey = 3; elems = "pgyx"; break;
|
||
case GCRY_PK_DSA: algoname = "dsa"; npkey = 4; elems = "pqgyx"; break;
|
||
case GCRY_PK_ECDSA: algoname = "ecdsa"; npkey = 6; elems = "pabgnqd"; break;
|
||
case GCRY_PK_ECDH: algoname = "ecdh"; npkey = 6; elems = "pabgnqd"; break;
|
||
default: algoname = ""; npkey = 0; elems = NULL; break;
|
||
}
|
||
assert (!elems || strlen (elems) < DIM (array) );
|
||
nskey = elems? strlen (elems) : 0;
|
||
|
||
if (!elems)
|
||
err = gpg_error (GPG_ERR_PUBKEY_ALGO);
|
||
else
|
||
err = key_from_sexp (list, elems, array);
|
||
gcry_sexp_release (list);
|
||
if (err)
|
||
return err;
|
||
|
||
gcry_create_nonce (protect_iv, sizeof protect_iv);
|
||
gcry_create_nonce (salt, sizeof salt);
|
||
/* We need to use the encoded S2k count. It is not possible to
|
||
encode it after it has been used because the encoding procedure
|
||
may round the value up. */
|
||
s2k_count = get_standard_s2k_count_rfc4880 ();
|
||
err = apply_protection (array, npkey, nskey, passphrase,
|
||
GCRY_CIPHER_AES, protect_iv, sizeof protect_iv,
|
||
3, GCRY_MD_SHA1, salt, s2k_count);
|
||
/* Turn it into the transfer key S-expression. Note that we always
|
||
return a protected key. */
|
||
if (!err)
|
||
{
|
||
char countbuf[35];
|
||
membuf_t mbuf;
|
||
void *format_args_buf_ptr[1];
|
||
int format_args_buf_int[1];
|
||
void *format_args[10+2];
|
||
unsigned int n;
|
||
gcry_sexp_t tmpkey, tmpsexp = NULL;
|
||
|
||
snprintf (countbuf, sizeof countbuf, "%lu", s2k_count);
|
||
|
||
init_membuf (&mbuf, 50);
|
||
put_membuf_str (&mbuf, "(skey");
|
||
for (i=j=0; i < npkey; i++)
|
||
{
|
||
put_membuf_str (&mbuf, " _ %m");
|
||
format_args[j++] = array + i;
|
||
}
|
||
put_membuf_str (&mbuf, " e %b");
|
||
format_args_buf_ptr[0] = gcry_mpi_get_opaque (array[npkey], &n);
|
||
format_args_buf_int[0] = (n+7)/8;
|
||
format_args[j++] = format_args_buf_int;
|
||
format_args[j++] = format_args_buf_ptr;
|
||
put_membuf_str (&mbuf, ")\n");
|
||
put_membuf (&mbuf, "", 1);
|
||
|
||
tmpkey = NULL;
|
||
{
|
||
char *format = get_membuf (&mbuf, NULL);
|
||
if (!format)
|
||
err = gpg_error_from_syserror ();
|
||
else
|
||
err = gcry_sexp_build_array (&tmpkey, NULL, format, format_args);
|
||
xfree (format);
|
||
}
|
||
if (!err)
|
||
err = gcry_sexp_build (&tmpsexp, NULL,
|
||
"(openpgp-private-key\n"
|
||
" (version 1:4)\n"
|
||
" (algo %s)\n"
|
||
" %S\n"
|
||
" (protection sha1 aes %b 1:3 sha1 %b %s))\n",
|
||
algoname,
|
||
tmpkey,
|
||
(int)sizeof protect_iv, protect_iv,
|
||
(int)sizeof salt, salt,
|
||
countbuf);
|
||
gcry_sexp_release (tmpkey);
|
||
if (!err)
|
||
err = make_canon_sexp_pad (tmpsexp, 0, r_transferkey, r_transferkeylen);
|
||
gcry_sexp_release (tmpsexp);
|
||
}
|
||
|
||
for (i=0; i < DIM (array); i++)
|
||
gcry_mpi_release (array[i]);
|
||
|
||
return err;
|
||
}
|