/*
* Linux kernel userspace API crypto backend implementation
*
* Copyright (C) 2010-2020 Red Hat, Inc. All rights reserved.
* Copyright (C) 2010-2020 Milan Broz
*
* This file is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This file 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this file; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/utsname.h>
#include <linux/if_alg.h>
#include "crypto_backend_internal.h"
/* FIXME: remove later */
#ifndef AF_ALG
#define AF_ALG 38
#endif
#ifndef SOL_ALG
#define SOL_ALG 279
#endif
static int crypto_backend_initialised = 0;
static char version[256];
struct hash_alg {
const char *name;
const char *kernel_name;
int length;
unsigned int block_length;
};
static struct hash_alg hash_algs[] = {
{ "sha1", "sha1", 20, 64 },
{ "sha224", "sha224", 28, 64 },
{ "sha256", "sha256", 32, 64 },
{ "sha384", "sha384", 48, 128 },
{ "sha512", "sha512", 64, 128 },
{ "ripemd160", "rmd160", 20, 64 },
{ "whirlpool", "wp512", 64, 64 },
{ "sha3-224", "sha3-224", 28, 144 },
{ "sha3-256", "sha3-256", 32, 136 },
{ "sha3-384", "sha3-384", 48, 104 },
{ "sha3-512", "sha3-512", 64, 72 },
{ "stribog256","streebog256", 32, 64 },
{ "stribog512","streebog512", 64, 64 },
{ "sm3", "sm3", 32, 64 },
{ NULL, NULL, 0, 0 }
};
struct crypt_hash {
int tfmfd;
int opfd;
int hash_len;
};
struct crypt_hmac {
int tfmfd;
int opfd;
int hash_len;
};
struct crypt_cipher {
struct crypt_cipher_kernel ck;
};
static int crypt_kernel_socket_init(struct sockaddr_alg *sa, int *tfmfd, int *opfd,
const void *key, size_t key_length)
{
*tfmfd = socket(AF_ALG, SOCK_SEQPACKET, 0);
if (*tfmfd < 0)
return -ENOTSUP;
if (bind(*tfmfd, (struct sockaddr *)sa, sizeof(*sa)) < 0) {
close(*tfmfd);
*tfmfd = -1;
return -ENOENT;
}
if (key && setsockopt(*tfmfd, SOL_ALG, ALG_SET_KEY, key, key_length) < 0) {
close(*tfmfd);
*tfmfd = -1;
return -EINVAL;
}
*opfd = accept(*tfmfd, NULL, 0);
if (*opfd < 0) {
close(*tfmfd);
*tfmfd = -1;
return -EINVAL;
}
return 0;
}
int crypt_backend_init(void)
{
struct utsname uts;
struct sockaddr_alg sa = {
.salg_family = AF_ALG,
.salg_type = "hash",
.salg_name = "sha256",
};
int tfmfd = -1, opfd = -1;
if (crypto_backend_initialised)
return 0;
if (uname(&uts) == -1 || strcmp(uts.sysname, "Linux"))
return -EINVAL;
if (crypt_kernel_socket_init(&sa, &tfmfd, &opfd, NULL, 0) < 0)
return -EINVAL;
close(tfmfd);
close(opfd);
snprintf(version, sizeof(version), "%s %s kernel cryptoAPI",
uts.sysname, uts.release);
crypto_backend_initialised = 1;
return 0;
}
void crypt_backend_destroy(void)
{
crypto_backend_initialised = 0;
}
uint32_t crypt_backend_flags(void)
{
return CRYPT_BACKEND_KERNEL;
}
const char *crypt_backend_version(void)
{
return crypto_backend_initialised ? version : "";
}
static struct hash_alg *_get_alg(const char *name)
{
int i = 0;
while (name && hash_algs[i].name) {
if (!strcmp(name, hash_algs[i].name))
return &hash_algs[i];
i++;
}
return NULL;
}
/* HASH */
int crypt_hash_size(const char *name)
{
struct hash_alg *ha = _get_alg(name);
return ha ? ha->length : -EINVAL;
}
int crypt_hash_init(struct crypt_hash **ctx, const char *name)
{
struct crypt_hash *h;
struct hash_alg *ha;
struct sockaddr_alg sa = {
.salg_family = AF_ALG,
.salg_type = "hash",
};
h = malloc(sizeof(*h));
if (!h)
return -ENOMEM;
ha = _get_alg(name);
if (!ha) {
free(h);
return -EINVAL;
}
h->hash_len = ha->length;
strncpy((char *)sa.salg_name, ha->kernel_name, sizeof(sa.salg_name)-1);
if (crypt_kernel_socket_init(&sa, &h->tfmfd, &h->opfd, NULL, 0) < 0) {
free(h);
return -EINVAL;
}
*ctx = h;
return 0;
}
int crypt_hash_write(struct crypt_hash *ctx, const char *buffer, size_t length)
{
ssize_t r;
r = send(ctx->opfd, buffer, length, MSG_MORE);
if (r < 0 || (size_t)r < length)
return -EIO;
return 0;
}
int crypt_hash_final(struct crypt_hash *ctx, char *buffer, size_t length)
{
ssize_t r;
if (length > (size_t)ctx->hash_len)
return -EINVAL;
r = read(ctx->opfd, buffer, length);
if (r < 0)
return -EIO;
return 0;
}
void crypt_hash_destroy(struct crypt_hash *ctx)
{
if (ctx->tfmfd >= 0)
close(ctx->tfmfd);
if (ctx->opfd >= 0)
close(ctx->opfd);
memset(ctx, 0, sizeof(*ctx));
free(ctx);
}
/* HMAC */
int crypt_hmac_size(const char *name)
{
return crypt_hash_size(name);
}
int crypt_hmac_init(struct crypt_hmac **ctx, const char *name,
const void *key, size_t key_length)
{
struct crypt_hmac *h;
struct hash_alg *ha;
struct sockaddr_alg sa = {
.salg_family = AF_ALG,
.salg_type = "hash",
};
h = malloc(sizeof(*h));
if (!h)
return -ENOMEM;
ha = _get_alg(name);
if (!ha) {
free(h);
return -EINVAL;
}
h->hash_len = ha->length;
snprintf((char *)sa.salg_name, sizeof(sa.salg_name),
"hmac(%s)", ha->kernel_name);
if (crypt_kernel_socket_init(&sa, &h->tfmfd, &h->opfd, key, key_length) < 0) {
free(h);
return -EINVAL;
}
*ctx = h;
return 0;
}
int crypt_hmac_write(struct crypt_hmac *ctx, const char *buffer, size_t length)
{
ssize_t r;
r = send(ctx->opfd, buffer, length, MSG_MORE);
if (r < 0 || (size_t)r < length)
return -EIO;
return 0;
}
int crypt_hmac_final(struct crypt_hmac *ctx, char *buffer, size_t length)
{
ssize_t r;
if (length > (size_t)ctx->hash_len)
return -EINVAL;
r = read(ctx->opfd, buffer, length);
if (r < 0)
return -EIO;
return 0;
}
void crypt_hmac_destroy(struct crypt_hmac *ctx)
{
if (ctx->tfmfd >= 0)
close(ctx->tfmfd);
if (ctx->opfd >= 0)
close(ctx->opfd);
memset(ctx, 0, sizeof(*ctx));
free(ctx);
}
/* RNG - N/A */
int crypt_backend_rng(char *buffer, size_t length, int quality, int fips)
{
return -EINVAL;
}
/* PBKDF */
int crypt_pbkdf(const char *kdf, const char *hash,
const char *password, size_t password_length,
const char *salt, size_t salt_length,
char *key, size_t key_length,
uint32_t iterations, uint32_t memory, uint32_t parallel)
{
struct hash_alg *ha;
if (!kdf)
return -EINVAL;
if (!strcmp(kdf, "pbkdf2")) {
ha = _get_alg(hash);
if (!ha)
return -EINVAL;
return pkcs5_pbkdf2(hash, password, password_length, salt, salt_length,
iterations, key_length, key, ha->block_length);
} else if (!strncmp(kdf, "argon2", 6)) {
return argon2(kdf, password, password_length, salt, salt_length,
key, key_length, iterations, memory, parallel);
}
return -EINVAL;
}
/* Block ciphers */
int crypt_cipher_init(struct crypt_cipher **ctx, const char *name,
const char *mode, const void *key, size_t key_length)
{
struct crypt_cipher *h;
int r;
h = malloc(sizeof(*h));
if (!h)
return -ENOMEM;
r = crypt_cipher_init_kernel(&h->ck, name, mode, key, key_length);
if (r < 0) {
free(h);
return r;
}
*ctx = h;
return 0;
}
void crypt_cipher_destroy(struct crypt_cipher *ctx)
{
crypt_cipher_destroy_kernel(&ctx->ck);
free(ctx);
}
int crypt_cipher_encrypt(struct crypt_cipher *ctx,
const char *in, char *out, size_t length,
const char *iv, size_t iv_length)
{
return crypt_cipher_encrypt_kernel(&ctx->ck, in, out, length, iv, iv_length);
}
int crypt_cipher_decrypt(struct crypt_cipher *ctx,
const char *in, char *out, size_t length,
const char *iv, size_t iv_length)
{
return crypt_cipher_decrypt_kernel(&ctx->ck, in, out, length, iv, iv_length);
}
bool crypt_cipher_kernel_only(struct crypt_cipher *ctx)
{
return true;
}
int crypt_bitlk_decrypt_key(const void *key, size_t key_length,
const char *in, char *out, size_t length,
const char *iv, size_t iv_length,
const char *tag, size_t tag_length)
{
return crypt_bitlk_decrypt_key_kernel(key, key_length, in, out, length,
iv, iv_length, tag, tag_length);
}