diff options
Diffstat (limited to 'crypto/userspace/ncr-dh.c')
| -rw-r--r-- | crypto/userspace/ncr-dh.c | 282 |
1 files changed, 282 insertions, 0 deletions
diff --git a/crypto/userspace/ncr-dh.c b/crypto/userspace/ncr-dh.c new file mode 100644 index 00000000000..00178420c31 --- /dev/null +++ b/crypto/userspace/ncr-dh.c @@ -0,0 +1,282 @@ +/* + * New driver for /dev/crypto device (aka CryptoDev) + + * Copyright (c) 2010 Katholieke Universiteit Leuven + * + * Author: Nikos Mavrogiannopoulos <nmav@gnutls.org> + * + * This file is part of linux cryptodev. + * + * This program 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 2 + * of the License, or (at your option) any later version. + * + * This program 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, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +#include <linux/cryptodev.h> +#include <linux/mm.h> +#include <linux/ncr.h> +#include <linux/random.h> +#include <asm/uaccess.h> +#include <asm/ioctl.h> +#include <linux/scatterlist.h> +#include <ncr-int.h> +#include <tomcrypt.h> +#include <ncr-dh.h> + +void dh_free(dh_key * key) +{ + mp_clear_multi(&key->p, &key->g, &key->x, NULL); +} + +int dh_import_params(dh_key * key, uint8_t * p, size_t p_size, uint8_t * g, + size_t g_size) +{ + int ret; + int err; + + if ((err = + mp_init_multi(&key->p, &key->g, &key->x, &key->y, + NULL)) != CRYPT_OK) { + err(); + return -ENOMEM; + } + + if ((err = + mp_read_unsigned_bin(&key->p, (unsigned char *) p, + p_size)) != CRYPT_OK) { + err(); + ret = _ncr_tomerr(err); + goto fail; + } + + if ((err = + mp_read_unsigned_bin(&key->g, (unsigned char *) g, + g_size)) != CRYPT_OK) { + err(); + ret = _ncr_tomerr(err); + goto fail; + } + + return 0; + fail: + mp_clear_multi(&key->p, &key->g, &key->x, &key->y, NULL); + + return ret; +} + +int dh_generate_key(dh_key * key) +{ + void *buf; + int size; + int err, ret; + + size = mp_unsigned_bin_size(&key->p); + if (size == 0) { + err(); + return -EINVAL; + } + + buf = kmalloc(size, GFP_KERNEL); + if (buf == NULL) { + err(); + return -ENOMEM; + } + + get_random_bytes(buf, size); + + if ((err = mp_read_unsigned_bin(&key->x, buf, size)) != CRYPT_OK) { + err(); + ret = _ncr_tomerr(err); + goto fail; + } + + err = mp_mod(&key->x, &key->p, &key->x); + if (err != CRYPT_OK) { + err(); + ret = _ncr_tomerr(err); + goto fail; + } + + key->type = PK_PRIVATE; + + ret = 0; + fail: + kfree(buf); + + return ret; + +} + +int dh_generate_public(dh_key * public, dh_key * private) +{ + int err, ret; + + err = + mp_exptmod(&private->g, &private->x, &private->p, &public->y); + if (err != CRYPT_OK) { + err(); + ret = _ncr_tomerr(err); + goto fail; + } + + public->type = PK_PUBLIC; + + ret = 0; + fail: + + return ret; +} + +int dh_export(uint8_t * out, unsigned long * outlen, int type, dh_key * key) +{ + unsigned long zero = 0; + int err; + + if (out == NULL || outlen == NULL || key == NULL) { + err(); + return -EINVAL; + } + + /* can we store the static header? */ + if (type == PK_PRIVATE && key->type != PK_PRIVATE) { + return -EINVAL; + } + + if (type != PK_PUBLIC && type != PK_PRIVATE) { + return -EINVAL; + } + + /* This encoding is different from the one in original + * libtomcrypt. It uses a compatible encoding with gnutls + * and openssl + */ + if (type == PK_PRIVATE) { + err = der_encode_sequence_multi(out, outlen, + LTC_ASN1_SHORT_INTEGER, 1UL, &zero, + LTC_ASN1_INTEGER, 1UL, &key->p, + LTC_ASN1_INTEGER, 1UL, &key->g, + LTC_ASN1_INTEGER, 1UL, &key->x, + LTC_ASN1_EOL, 0UL, NULL); + } else { + err = mp_unsigned_bin_size(&key->y); + if (err > *outlen) { + err(); + return -EOVERFLOW; + } + + *outlen = err; + + err = mp_to_unsigned_bin(&key->y, out); + } + + if (err != CRYPT_OK) { + err(); + return _ncr_tomerr(err); + } + + return 0; +} + +int dh_import(const uint8_t * in, size_t inlen, dh_key * key) +{ + int err; + unsigned long zero = 0; + + if (in == NULL || key == NULL) { + err(); + return -EINVAL; + } + + /* init key */ + if (mp_init_multi + (&key->p, &key->g, &key->x, &key->y, NULL) != CRYPT_OK) { + return -ENOMEM; + } + + /* get key type */ + if ((err = der_decode_sequence_multi(in, inlen, + LTC_ASN1_SHORT_INTEGER, 1UL, &zero, + LTC_ASN1_INTEGER, 1UL, &key->p, + LTC_ASN1_INTEGER, 1UL, &key->g, + LTC_ASN1_INTEGER, 1UL, &key->x, + LTC_ASN1_EOL, 0UL, NULL)) == CRYPT_OK) { + key->type = PK_PRIVATE; + } else { /* public */ + err = mp_read_unsigned_bin(&key->y, in, inlen); + key->type = PK_PUBLIC; + } + + if (err != CRYPT_OK) { + goto LBL_ERR; + } + + return 0; + + LBL_ERR: + mp_clear_multi(&key->p, &key->g, &key->x, &key->y, NULL); + return _ncr_tomerr(err); +} + +int dh_derive_gxy(struct key_item_st* newkey, dh_key * key, + void* pk, size_t pk_size) +{ +int ret, err; +mp_int y, gxy; + /* newkey will be a secret key with value of g^{xy} + */ + + if (mp_init_multi(&y, &gxy, NULL) != CRYPT_OK) { + err(); + return -ENOMEM; + } + + if (key->type != PK_PRIVATE) { + err(); + return -EINVAL; + } + + if ((err=mp_read_unsigned_bin(&y, pk, pk_size)) != CRYPT_OK) { + err(); + ret = _ncr_tomerr(err); + goto fail; + } + + if ((err=mp_exptmod(&y, &key->x, &key->p, &gxy))!= CRYPT_OK) { + err(); + ret = _ncr_tomerr(err); + goto fail; + } + + err = mp_unsigned_bin_size(&gxy); + if (err > NCR_CIPHER_MAX_KEY_LEN) { + err(); + ret = -EOVERFLOW; + goto fail; + } + newkey->key.secret.size = err; + + err = mp_to_unsigned_bin(&gxy, newkey->key.secret.data); + if (err != CRYPT_OK) { + err(); + ret = _ncr_tomerr(err); + goto fail; + } + + newkey->type = NCR_KEY_TYPE_SECRET; + + ret = 0; +fail: + mp_clear_multi(&y, &gxy, NULL); + + return ret; +} |