static gboolean
compare_keys (gcry_sexp_t key, gcry_sexp_t sexp)
{
guchar hash1[20], hash2[20];
guchar *p;
/* Now compare them */
p = gcry_pk_get_keygrip (key, hash1);
g_assert ("couldn't get key id for private key" && p == hash1);
p = gcry_pk_get_keygrip (sexp, hash2);
g_assert ("couldn't get key id for parsed private key" && p == hash2);
return memcmp (hash1, hash2, 20) == 0;
}
static void
check_pubkey_grip (int n, const unsigned char *grip,
gcry_sexp_t skey, gcry_sexp_t pkey)
{
unsigned char sgrip[20], pgrip[20];
if (!gcry_pk_get_keygrip (skey, sgrip))
die ("get keygrip for private RSA key failed\n");
if (!gcry_pk_get_keygrip (pkey, pgrip))
die ("[%i] get keygrip for public RSA key failed\n", n);
if (memcmp (sgrip, pgrip, 20))
fail ("[%i] keygrips don't match\n", n);
if (memcmp (sgrip, grip, 20))
fail ("wrong keygrip for RSA key\n");
}
/** Calculate hex-encoded keygrip of public key in sexp. */
char *keyutil_get_cert_hexgrip (gcry_sexp_t sexp)
{
char *ret = NULL;
unsigned char grip[20];
if (gcry_pk_get_keygrip (sexp, grip)) {
ret = encoding_bin2hex (grip, sizeof (grip));
}
return ret;
}
/* Return the so called "keygrip" which is the SHA-1 hash of the
public key parameters expressed in a way depended on the algorithm.
KEY is expected to be an canonical encoded S-expression with a
public or private key. KEYLEN is the length of that buffer.
GRIP must be at least 20 bytes long. On success 0 is returned, on
error an error code. */
gpg_error_t
keygrip_from_canon_sexp (const unsigned char *key, size_t keylen,
unsigned char *grip)
{
gpg_error_t err;
gcry_sexp_t sexp;
if (!grip)
return gpg_error (GPG_ERR_INV_VALUE);
err = gcry_sexp_sscan (&sexp, NULL, (const char *)key, keylen);
if (err)
return err;
if (!gcry_pk_get_keygrip (sexp, grip))
err = gpg_error (GPG_ERR_INTERNAL);
gcry_sexp_release (sexp);
return err;
}
/* Return the so called KEYGRIP which is the SHA-1 hash of the public
key parameters expressed as an canoncial encoded S-Exp. ARRAY must
be 20 bytes long. Returns ARRAY or a newly allocated buffer if ARRAY was
given as NULL. May return NULL on error. */
unsigned char *
gpgsm_get_keygrip (ksba_cert_t cert, unsigned char *array)
{
gcry_sexp_t s_pkey;
int rc;
ksba_sexp_t p;
size_t n;
p = ksba_cert_get_public_key (cert);
if (!p)
return NULL; /* oops */
if (DBG_X509)
log_debug ("get_keygrip for public key\n");
n = gcry_sexp_canon_len (p, 0, NULL, NULL);
if (!n)
{
log_error ("libksba did not return a proper S-Exp\n");
return NULL;
}
rc = gcry_sexp_sscan ( &s_pkey, NULL, (char*)p, n);
xfree (p);
if (rc)
{
log_error ("gcry_sexp_scan failed: %s\n", gpg_strerror (rc));
return NULL;
}
array = gcry_pk_get_keygrip (s_pkey, array);
gcry_sexp_release (s_pkey);
if (!array)
{
rc = gpg_error (GPG_ERR_GENERAL);
log_error ("can't calculate keygrip\n");
return NULL;
}
if (DBG_X509)
log_printhex ("keygrip=", array, 20);
return array;
}
/* Get the keygrip from CERT, return 0 on success */
int
card_help_get_keygrip (ksba_cert_t cert, unsigned char *array)
{
gcry_sexp_t s_pkey;
int rc;
ksba_sexp_t p;
size_t n;
p = ksba_cert_get_public_key (cert);
if (!p)
return -1; /* oops */
n = gcry_sexp_canon_len (p, 0, NULL, NULL);
if (!n)
return -1; /* libksba did not return a proper S-expression */
rc = gcry_sexp_sscan ( &s_pkey, NULL, p, n);
xfree (p);
if (rc)
return -1; /* can't parse that S-expression */
array = gcry_pk_get_keygrip (s_pkey, array);
gcry_sexp_release (s_pkey);
if (!array)
return -1; /* failed to calculate the keygrip */
return 0;
}
/* Return true if the key in BLOB matches the 20 bytes keygrip GRIP.
We don't have the keygrips as meta data, thus we need to parse the
certificate. Fixme: We might want to return proper error codes
instead of failing a search for invalid certificates etc. */
static int
blob_x509_has_grip (KEYBOXBLOB blob, const unsigned char *grip)
{
int rc;
const unsigned char *buffer;
size_t length;
size_t cert_off, cert_len;
ksba_reader_t reader = NULL;
ksba_cert_t cert = NULL;
ksba_sexp_t p = NULL;
gcry_sexp_t s_pkey;
unsigned char array[20];
unsigned char *rcp;
size_t n;
buffer = _keybox_get_blob_image (blob, &length);
if (length < 40)
return 0; /* Too short. */
cert_off = get32 (buffer+8);
cert_len = get32 (buffer+12);
if (cert_off+cert_len > length)
return 0; /* Too short. */
rc = ksba_reader_new (&reader);
if (rc)
return 0; /* Problem with ksba. */
rc = ksba_reader_set_mem (reader, buffer+cert_off, cert_len);
if (rc)
goto failed;
rc = ksba_cert_new (&cert);
if (rc)
goto failed;
rc = ksba_cert_read_der (cert, reader);
if (rc)
goto failed;
p = ksba_cert_get_public_key (cert);
if (!p)
goto failed;
n = gcry_sexp_canon_len (p, 0, NULL, NULL);
if (!n)
goto failed;
rc = gcry_sexp_sscan (&s_pkey, NULL, (char*)p, n);
if (rc)
{
gcry_sexp_release (s_pkey);
goto failed;
}
rcp = gcry_pk_get_keygrip (s_pkey, array);
gcry_sexp_release (s_pkey);
if (!rcp)
goto failed; /* Can't calculate keygrip. */
xfree (p);
ksba_cert_release (cert);
ksba_reader_release (reader);
return !memcmp (array, grip, 20);
failed:
xfree (p);
ksba_cert_release (cert);
ksba_reader_release (reader);
return 0;
}
/* Assume that the reader is at a pkcs#12 message and try to import
certificates from that stupid format. We will transfer secret
keys to the agent. */
static gpg_error_t
parse_p12 (ctrl_t ctrl, ksba_reader_t reader, struct stats_s *stats)
{
gpg_error_t err = 0;
char buffer[1024];
size_t ntotal, nread;
membuf_t p12mbuf;
char *p12buffer = NULL;
size_t p12buflen;
size_t p12bufoff;
gcry_mpi_t *kparms = NULL;
struct rsa_secret_key_s sk;
char *passphrase = NULL;
unsigned char *key = NULL;
size_t keylen;
void *kek = NULL;
size_t keklen;
unsigned char *wrappedkey = NULL;
size_t wrappedkeylen;
gcry_cipher_hd_t cipherhd = NULL;
gcry_sexp_t s_key = NULL;
unsigned char grip[20];
int bad_pass = 0;
int i;
struct store_cert_parm_s store_cert_parm;
memset (&store_cert_parm, 0, sizeof store_cert_parm);
store_cert_parm.ctrl = ctrl;
store_cert_parm.stats = stats;
init_membuf (&p12mbuf, 4096);
ntotal = 0;
while (!(err = ksba_reader_read (reader, buffer, sizeof buffer, &nread)))
{
if (ntotal >= MAX_P12OBJ_SIZE*1024)
{
/* Arbitrary limit to avoid DoS attacks. */
err = gpg_error (GPG_ERR_TOO_LARGE);
log_error ("pkcs#12 object is larger than %dk\n", MAX_P12OBJ_SIZE);
break;
}
put_membuf (&p12mbuf, buffer, nread);
ntotal += nread;
}
if (gpg_err_code (err) == GPG_ERR_EOF)
err = 0;
if (!err)
{
p12buffer = get_membuf (&p12mbuf, &p12buflen);
if (!p12buffer)
err = gpg_error_from_syserror ();
}
if (err)
{
log_error (_("error reading input: %s\n"), gpg_strerror (err));
goto leave;
}
/* GnuPG 2.0.4 accidently created binary P12 files with the string
"The passphrase is %s encoded.\n\n" prepended to the ASN.1 data.
We fix that here. */
if (p12buflen > 29 && !memcmp (p12buffer, "The passphrase is ", 18))
{
for (p12bufoff=18;
p12bufoff < p12buflen && p12buffer[p12bufoff] != '\n';
p12bufoff++)
;
p12bufoff++;
if (p12bufoff < p12buflen && p12buffer[p12bufoff] == '\n')
p12bufoff++;
}
else
p12bufoff = 0;
err = gpgsm_agent_ask_passphrase
(ctrl,
i18n_utf8 ("Please enter the passphrase to unprotect the PKCS#12 object."),
0, &passphrase);
if (err)
goto leave;
kparms = p12_parse (p12buffer + p12bufoff, p12buflen - p12bufoff,
passphrase, store_cert_cb, &store_cert_parm, &bad_pass);
xfree (passphrase);
passphrase = NULL;
if (!kparms)
{
log_error ("error parsing or decrypting the PKCS#12 file\n");
err = gpg_error (GPG_ERR_INV_OBJ);
goto leave;
}
/* print_mpi (" n", kparms[0]); */
/* print_mpi (" e", kparms[1]); */
/* print_mpi (" d", kparms[2]); */
/* print_mpi (" p", kparms[3]); */
/* print_mpi (" q", kparms[4]); */
/* print_mpi ("dmp1", kparms[5]); */
/* print_mpi ("dmq1", kparms[6]); */
/* print_mpi (" u", kparms[7]); */
sk.n = kparms[0];
sk.e = kparms[1];
sk.d = kparms[2];
sk.q = kparms[3];
sk.p = kparms[4];
sk.u = kparms[7];
err = rsa_key_check (&sk);
if (err)
goto leave;
/* print_mpi (" n", sk.n); */
/* print_mpi (" e", sk.e); */
/* print_mpi (" d", sk.d); */
/* print_mpi (" p", sk.p); */
/* print_mpi (" q", sk.q); */
/* print_mpi (" u", sk.u); */
/* Create an S-expresion from the parameters. */
err = gcry_sexp_build (&s_key, NULL,
"(private-key(rsa(n%m)(e%m)(d%m)(p%m)(q%m)(u%m)))",
sk.n, sk.e, sk.d, sk.p, sk.q, sk.u, NULL);
for (i=0; i < 8; i++)
gcry_mpi_release (kparms[i]);
gcry_free (kparms);
kparms = NULL;
if (err)
{
log_error ("failed to create S-expression from key: %s\n",
gpg_strerror (err));
goto leave;
}
/* Compute the keygrip. */
if (!gcry_pk_get_keygrip (s_key, grip))
{
err = gpg_error (GPG_ERR_GENERAL);
log_error ("can't calculate keygrip\n");
goto leave;
}
log_printhex ("keygrip=", grip, 20);
/* Convert to canonical encoding using a function which pads it to a
multiple of 64 bits. We need this padding for AESWRAP. */
err = make_canon_sexp_pad (s_key, 1, &key, &keylen);
if (err)
{
log_error ("error creating canonical S-expression\n");
goto leave;
}
gcry_sexp_release (s_key);
s_key = NULL;
/* Get the current KEK. */
err = gpgsm_agent_keywrap_key (ctrl, 0, &kek, &keklen);
if (err)
{
log_error ("error getting the KEK: %s\n", gpg_strerror (err));
goto leave;
}
/* Wrap the key. */
err = gcry_cipher_open (&cipherhd, GCRY_CIPHER_AES128,
GCRY_CIPHER_MODE_AESWRAP, 0);
if (err)
goto leave;
err = gcry_cipher_setkey (cipherhd, kek, keklen);
if (err)
goto leave;
xfree (kek);
kek = NULL;
wrappedkeylen = keylen + 8;
wrappedkey = xtrymalloc (wrappedkeylen);
if (!wrappedkey)
{
err = gpg_error_from_syserror ();
goto leave;
}
err = gcry_cipher_encrypt (cipherhd, wrappedkey, wrappedkeylen, key, keylen);
if (err)
goto leave;
xfree (key);
key = NULL;
gcry_cipher_close (cipherhd);
cipherhd = NULL;
/* Send the wrapped key to the agent. */
err = gpgsm_agent_import_key (ctrl, wrappedkey, wrappedkeylen);
if (!err)
{
stats->count++;
stats->secret_read++;
stats->secret_imported++;
}
else if ( gpg_err_code (err) == GPG_ERR_EEXIST )
{
err = 0;
stats->count++;
stats->secret_read++;
stats->secret_dups++;
}
/* If we did not get an error from storing the secret key we return
a possible error from parsing the certificates. We do this after
storing the secret keys so that a bad certificate does not
inhibit our chance to store the secret key. */
if (!err && store_cert_parm.err)
err = store_cert_parm.err;
leave:
if (kparms)
{
for (i=0; i < 8; i++)
gcry_mpi_release (kparms[i]);
gcry_free (kparms);
kparms = NULL;
}
xfree (key);
gcry_sexp_release (s_key);
xfree (passphrase);
gcry_cipher_close (cipherhd);
xfree (wrappedkey);
xfree (kek);
xfree (get_membuf (&p12mbuf, NULL));
xfree (p12buffer);
if (bad_pass)
{
/* We only write a plain error code and not direct
BAD_PASSPHRASE because the pkcs12 parser might issue this
message multiple times, BAD_PASSPHRASE in general requires a
keyID and parts of the import might actually succeed so that
IMPORT_PROBLEM is also not appropriate. */
gpgsm_status_with_err_code (ctrl, STATUS_ERROR,
"import.parsep12", GPG_ERR_BAD_PASSPHRASE);
}
return err;
}