/*
* utils_crypt - cipher utilities for cryptsetup
*
* Copyright (C) 2004-2007 Clemens Fruhwirth <clemens@endorphin.org>
* Copyright (C) 2009-2020 Red Hat, Inc. All rights reserved.
* Copyright (C) 2009-2020 Milan Broz
*
* 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 <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include "libcryptsetup.h"
#include "utils_crypt.h"
int crypt_parse_name_and_mode(const char *s, char *cipher, int *key_nums,
char *cipher_mode)
{
if (!s || !cipher || !cipher_mode)
return -EINVAL;
if (sscanf(s, "%" MAX_CIPHER_LEN_STR "[^-]-%" MAX_CIPHER_LEN_STR "s",
cipher, cipher_mode) == 2) {
if (!strcmp(cipher_mode, "plain"))
strcpy(cipher_mode, "cbc-plain");
if (key_nums) {
char *tmp = strchr(cipher, ':');
*key_nums = tmp ? atoi(++tmp) : 1;
if (!*key_nums)
return -EINVAL;
}
return 0;
}
/* Short version for "empty" cipher */
if (!strcmp(s, "null") || !strcmp(s, "cipher_null")) {
strcpy(cipher, "cipher_null");
strcpy(cipher_mode, "ecb");
if (key_nums)
*key_nums = 0;
return 0;
}
if (sscanf(s, "%" MAX_CIPHER_LEN_STR "[^-]", cipher) == 1) {
strcpy(cipher_mode, "cbc-plain");
if (key_nums)
*key_nums = 1;
return 0;
}
return -EINVAL;
}
int crypt_parse_hash_integrity_mode(const char *s, char *integrity)
{
char mode[MAX_CIPHER_LEN], hash[MAX_CIPHER_LEN];
int r;
if (!s || !integrity || strchr(s, '(') || strchr(s, ')'))
return -EINVAL;
r = sscanf(s, "%" MAX_CIPHER_LEN_STR "[^-]-%" MAX_CIPHER_LEN_STR "s", mode, hash);
if (r == 2)
r = snprintf(integrity, MAX_CIPHER_LEN, "%s(%s)", mode, hash);
else if (r == 1)
r = snprintf(integrity, MAX_CIPHER_LEN, "%s", mode);
else
return -EINVAL;
if (r < 0 || r == MAX_CIPHER_LEN)
return -EINVAL;
return 0;
}
int crypt_parse_integrity_mode(const char *s, char *integrity,
int *integrity_key_size)
{
int ks = 0, r = 0;
if (!s || !integrity)
return -EINVAL;
// FIXME: do not hardcode it here
/* AEAD modes */
if (!strcmp(s, "aead") ||
!strcmp(s, "poly1305") ||
!strcmp(s, "none")) {
strncpy(integrity, s, MAX_CIPHER_LEN);
ks = 0;
} else if (!strcmp(s, "hmac-sha1")) {
strncpy(integrity, "hmac(sha1)", MAX_CIPHER_LEN);
ks = 20;
} else if (!strcmp(s, "hmac-sha256")) {
strncpy(integrity, "hmac(sha256)", MAX_CIPHER_LEN);
ks = 32;
} else if (!strcmp(s, "hmac-sha512")) {
ks = 64;
strncpy(integrity, "hmac(sha512)", MAX_CIPHER_LEN);
} else if (!strcmp(s, "cmac-aes")) {
ks = 16;
strncpy(integrity, "cmac(aes)", MAX_CIPHER_LEN);
} else
r = -EINVAL;
if (integrity_key_size)
*integrity_key_size = ks;
return r;
}
int crypt_parse_pbkdf(const char *s, const char **pbkdf)
{
const char *tmp = NULL;
if (!s)
return -EINVAL;
if (!strcasecmp(s, CRYPT_KDF_PBKDF2))
tmp = CRYPT_KDF_PBKDF2;
else if (!strcasecmp(s, CRYPT_KDF_ARGON2I))
tmp = CRYPT_KDF_ARGON2I;
else if (!strcasecmp(s, CRYPT_KDF_ARGON2ID))
tmp = CRYPT_KDF_ARGON2ID;
if (!tmp)
return -EINVAL;
if (pbkdf)
*pbkdf = tmp;
return 0;
}
ssize_t crypt_hex_to_bytes(const char *hex, char **result, int safe_alloc)
{
char buf[3] = "xx\0", *endp, *bytes;
size_t i, len;
len = strlen(hex);
if (len % 2)
return -EINVAL;
len /= 2;
bytes = safe_alloc ? crypt_safe_alloc(len) : malloc(len);
if (!bytes)
return -ENOMEM;
for (i = 0; i < len; i++) {
memcpy(buf, &hex[i * 2], 2);
bytes[i] = strtoul(buf, &endp, 16);
if (endp != &buf[2]) {
safe_alloc ? crypt_safe_free(bytes) : free(bytes);
return -EINVAL;
}
}
*result = bytes;
return i;
}