/**
* cdk_stream_peek:
* @inp: the input stream handle
* @s: buffer
* @count: number of bytes to peek
*
* The function acts like cdk_stream_read with the difference that
* the file pointer is moved to the old position after the bytes were read.
**/
int
cdk_stream_peek( cdk_stream_t inp, byte *s, size_t count )
{
unsigned off;
int nbytes, rc;
if( !inp || !s )
return CDK_Inv_Value;
off = cdk_stream_tell( inp );
nbytes = _cdk_stream_gets( inp, s, count );
rc = cdk_stream_seek( inp, off );
if( rc )
return 0;
return nbytes;
}
static cdk_error_t
file_verify_clearsign (cdk_ctx_t hd, const char *file, const char *output)
{
cdk_stream_t inp = NULL, out = NULL, tmp = NULL;
digest_hd_st md;
char buf[512], chk[512];
const char *s;
int i, is_signed = 0, nbytes;
int digest_algo = 0;
int err;
cdk_error_t rc;
memset(&md, 0, sizeof(md));
if (output)
{
rc = cdk_stream_create (output, &out);
if (rc)
return rc;
}
rc = cdk_stream_open (file, &inp);
if (rc)
{
if (output)
cdk_stream_close (out);
return rc;
}
s = "-----BEGIN PGP SIGNED MESSAGE-----";
while (!cdk_stream_eof (inp))
{
nbytes = _cdk_stream_gets (inp, buf, DIM (buf) - 1);
if (!nbytes || nbytes == -1)
break;
if (!strncmp (buf, s, strlen (s)))
{
is_signed = 1;
break;
}
}
if (cdk_stream_eof (inp) && !is_signed)
{
rc = CDK_Armor_Error;
goto leave;
}
while (!cdk_stream_eof (inp))
{
nbytes = _cdk_stream_gets (inp, buf, DIM (buf) - 1);
if (!nbytes || nbytes == -1)
break;
if (nbytes == 1) /* Empty line */
break;
else if (!strncmp (buf, "Hash: ", 6))
{
for (i = 0; digest_table[i].name; i++)
{
if (!strcmp (buf + 6, digest_table[i].name))
{
digest_algo = digest_table[i].algo;
break;
}
}
}
}
if (digest_algo && _gnutls_hash_get_algo_len (digest_algo) <= 0)
{
rc = CDK_Inv_Algo;
goto leave;
}
if (!digest_algo)
digest_algo = GNUTLS_DIG_MD5;
err = _gnutls_hash_init (&md, digest_algo);
if (err < 0)
{
rc = map_gnutls_error (err);
goto leave;
}
s = "-----BEGIN PGP SIGNATURE-----";
while (!cdk_stream_eof (inp))
{
nbytes = _cdk_stream_gets (inp, buf, DIM (buf) - 1);
if (!nbytes || nbytes == -1)
break;
if (!strncmp (buf, s, strlen (s)))
break;
else
{
cdk_stream_peek (inp, (byte *) chk, DIM (chk) - 1);
i = strncmp (chk, s, strlen (s));
if (strlen (buf) == 0 && i == 0)
continue; /* skip last '\n' */
_cdk_trim_string (buf, i == 0 ? 0 : 1);
_gnutls_hash (&md, buf, strlen (buf));
}
if (!strncmp (buf, "- ", 2)) /* FIXME: handle it recursive. */
memmove (buf, buf + 2, nbytes - 2);
if (out)
{
if (strstr (buf, "\r\n"))
buf[strlen (buf) - 2] = '\0';
cdk_stream_write (out, buf, strlen (buf));
_cdk_stream_puts (out, _cdk_armor_get_lineend ());
}
}
/* We create a temporary stream object to store the
signature data in there. */
rc = cdk_stream_tmp_new (&tmp);
if (rc)
goto leave;
s = "-----BEGIN PGP SIGNATURE-----\n";
_cdk_stream_puts (tmp, s);
while (!cdk_stream_eof (inp))
{
nbytes = _cdk_stream_gets (inp, buf, DIM (buf) - 1);
if (!nbytes || nbytes == -1)
break;
if (nbytes < (int) (DIM (buf) - 3))
{
buf[nbytes - 1] = '\n';
buf[nbytes] = '\0';
}
cdk_stream_write (tmp, buf, nbytes);
}
/* FIXME: This code is not very elegant. */
cdk_stream_tmp_set_mode (tmp, STREAMCTL_READ);
cdk_stream_seek (tmp, 0);
cdk_stream_set_armor_flag (tmp, 0);
cdk_stream_read (tmp, NULL, 0);
/* the digest handle will be closed there. */
rc = _cdk_proc_packets (hd, tmp, NULL, NULL, NULL, &md);
leave:
_gnutls_hash_deinit (&md, NULL);
cdk_stream_close (out);
cdk_stream_close (tmp);
cdk_stream_close (inp);
return rc;
}