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mirror of git://git.gnupg.org/gnupg.git synced 2024-12-24 10:39:57 +01:00
gnupg/scd/app-help.c
Werner Koch b008274afd Nuked almost all trailing white space.
We better do this once and for all instead of cluttering all future
commits with diffs of trailing white spaces.  In the majority of cases
blank or single lines are affected and thus this change won't disturb
a git blame too much.  For future commits the pre-commit scripts
checks that this won't happen again.
2011-02-04 12:57:53 +01:00

181 lines
4.8 KiB
C

/* app-help.c - Application helper functions
* Copyright (C) 2004, 2009 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* GnuPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* GnuPG is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "scdaemon.h"
#include "app-common.h"
#include "iso7816.h"
#include "tlv.h"
/* Count the number of bits, assuming the A represents an unsigned big
integer of length LEN bytes. If A is NULL a length of 0 is
returned. */
unsigned int
app_help_count_bits (const unsigned char *a, size_t len)
{
unsigned int n = len * 8;
int i;
if (!a)
return 0;
for (; len && !*a; len--, a++, n -=8)
;
if (len)
{
for (i=7; i && !(*a & (1<<i)); i--)
n--;
}
return n;
}
/* Return the KEYGRIP for the certificate CERT as an hex encoded
string in the user provided buffer HEXKEYGRIP which must be of at
least 41 bytes. */
gpg_error_t
app_help_get_keygrip_string (ksba_cert_t cert, char *hexkeygrip)
{
gpg_error_t err;
gcry_sexp_t s_pkey;
ksba_sexp_t p;
size_t n;
unsigned char array[20];
p = ksba_cert_get_public_key (cert);
if (!p)
return gpg_error (GPG_ERR_BUG);
n = gcry_sexp_canon_len (p, 0, NULL, NULL);
if (!n)
return gpg_error (GPG_ERR_INV_SEXP);
err = gcry_sexp_sscan (&s_pkey, NULL, (char*)p, n);
xfree (p);
if (err)
return err; /* Can't parse that S-expression. */
if (!gcry_pk_get_keygrip (s_pkey, array))
{
gcry_sexp_release (s_pkey);
return gpg_error (GPG_ERR_GENERAL); /* Failed to calculate the keygrip.*/
}
gcry_sexp_release (s_pkey);
bin2hex (array, 20, hexkeygrip);
return 0;
}
/* Given the SLOT and the File ID FID, return the length of the
certificate contained in that file. Returns 0 if the file does not
exists or does not contain a certificate. If R_CERTOFF is not
NULL, the length the header will be stored at this address; thus to
parse the X.509 certificate a read should start at that offset.
On success the file is still selected.
*/
size_t
app_help_read_length_of_cert (int slot, int fid, size_t *r_certoff)
{
gpg_error_t err;
unsigned char *buffer;
const unsigned char *p;
size_t buflen, n;
int class, tag, constructed, ndef;
size_t resultlen, objlen, hdrlen;
err = iso7816_select_file (slot, fid, 0, NULL, NULL);
if (err)
{
log_info ("error selecting FID 0x%04X: %s\n", fid, gpg_strerror (err));
return 0;
}
err = iso7816_read_binary (slot, 0, 32, &buffer, &buflen);
if (err)
{
log_info ("error reading certificate from FID 0x%04X: %s\n",
fid, gpg_strerror (err));
return 0;
}
if (!buflen || *buffer == 0xff)
{
log_info ("no certificate contained in FID 0x%04X\n", fid);
xfree (buffer);
return 0;
}
p = buffer;
n = buflen;
err = parse_ber_header (&p, &n, &class, &tag, &constructed,
&ndef, &objlen, &hdrlen);
if (err)
{
log_info ("error parsing certificate in FID 0x%04X: %s\n",
fid, gpg_strerror (err));
xfree (buffer);
return 0;
}
/* All certificates should commence with a SEQUENCE except for the
special ROOT CA which are enclosed in a SET. */
if ( !(class == CLASS_UNIVERSAL && constructed
&& (tag == TAG_SEQUENCE || tag == TAG_SET)))
{
log_info ("data at FID 0x%04X does not look like a certificate\n", fid);
return 0;
}
resultlen = objlen + hdrlen;
if (r_certoff)
{
/* The callers want the offset to the actual certificate. */
*r_certoff = hdrlen;
err = parse_ber_header (&p, &n, &class, &tag, &constructed,
&ndef, &objlen, &hdrlen);
if (err)
return 0;
if (class == CLASS_UNIVERSAL && tag == TAG_OBJECT_ID && !constructed)
{
/* The certificate seems to be contained in a
userCertificate container. Assume the following sequence
is the certificate. */
*r_certoff += hdrlen + objlen;
if (*r_certoff > resultlen)
{
*r_certoff = 0;
return 0; /* That should never happen. */
}
}
else
*r_certoff = 0;
}
return resultlen;
}