Files
cryptsetup/lib/crypto_backend/cipher_generic.c
Milan Broz ccc0c69cd7 Add fips_mode check for kernel.
Akso add a separate function so we can detect that kernel and crypto
lib is in different FIPS state (only for testing).
2025-11-19 22:09:27 +01:00

100 lines
2.3 KiB
C

// SPDX-License-Identifier: LGPL-2.1-or-later
/*
* Linux kernel cipher generic utilities
*
* Copyright (C) 2018-2025 Red Hat, Inc. All rights reserved.
* Copyright (C) 2018-2025 Milan Broz
*/
#include <errno.h>
#include <strings.h>
#include <unistd.h>
#include <fcntl.h>
#include "crypto_backend.h"
struct cipher_alg {
const char *name;
const char *mode;
int blocksize;
bool wrapped_key;
};
static const struct cipher_alg cipher_algs[] = {
{ "cipher_null", NULL, 16, false },
{ "aes", NULL, 16, false },
{ "serpent", NULL, 16, false },
{ "twofish", NULL, 16, false },
{ "anubis", NULL, 16, false },
{ "blowfish", NULL, 8, false },
{ "camellia", NULL, 16, false },
{ "cast5", NULL, 8, false },
{ "cast6", NULL, 16, false },
{ "des", NULL, 8, false },
{ "des3_ede", NULL, 8, false },
{ "khazad", NULL, 8, false },
{ "seed", NULL, 16, false },
{ "tea", NULL, 8, false },
{ "xtea", NULL, 8, false },
{ "paes", NULL, 16, true }, /* protected AES, s390 wrapped key scheme */
{ "xchacha12,aes", "adiantum", 32, false },
{ "xchacha20,aes", "adiantum", 32, false },
{ "sm4", NULL, 16, false },
{ "aria", NULL, 16, false },
{ NULL, NULL, 0, false }
};
static const struct cipher_alg *_get_alg(const char *name, const char *mode)
{
int i = 0;
while (name && cipher_algs[i].name) {
if (!strcasecmp(name, cipher_algs[i].name))
if (!mode || !cipher_algs[i].mode ||
!strncasecmp(mode, cipher_algs[i].mode, strlen(cipher_algs[i].mode)))
return &cipher_algs[i];
i++;
}
return NULL;
}
int crypt_cipher_ivsize(const char *name, const char *mode)
{
const struct cipher_alg *ca = _get_alg(name, mode);
if (!ca)
return -EINVAL;
if (mode && !strcasecmp(mode, "hctr2"))
return 32;
if (mode && !strcasecmp(mode, "ecb"))
return 0;
return ca->blocksize;
}
int crypt_cipher_wrapped_key(const char *name, const char *mode)
{
const struct cipher_alg *ca = _get_alg(name, mode);
return ca ? (int)ca->wrapped_key : 0;
}
bool crypt_fips_mode_kernel(void)
{
int fd;
char buf = 0;
fd = open("/proc/sys/crypto/fips_enabled", O_RDONLY);
if (fd < 0)
return false;
if (read(fd, &buf, 1) != 1)
buf = '0';
close(fd);
return (buf == '1');
}