/*      $NetBSD: chacha_impl.c,v 1.4 2022/11/05 17:36:33 jmcneill Exp $ */

/*-
* Copyright (c) 2020 The NetBSD Foundation, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

#include <sys/types.h>
#include <sys/cdefs.h>
#include <sys/errno.h>
#include <sys/module.h>
#include <sys/once.h>
#include <sys/sysctl.h>

#include <lib/libkern/libkern.h>

#include "chacha.h"
#include "chacha_ref.h"

static const struct chacha_impl *chacha_md_impl __read_mostly;
static const struct chacha_impl *chacha_impl __read_mostly = &chacha_ref_impl;

static int
sysctl_kern_crypto_chacha_selected(SYSCTLFN_ARGS)
{
       struct sysctlnode node;

       node = *rnode;
       node.sysctl_data = __UNCONST(chacha_impl->ci_name);
       node.sysctl_size = strlen(chacha_impl->ci_name) + 1;
       return sysctl_lookup(SYSCTLFN_CALL(&node));
}

SYSCTL_SETUP(sysctl_kern_crypto_chacha_setup, "sysctl kern.crypto.chacha setup")
{
       const struct sysctlnode *cnode;
       const struct sysctlnode *chacha_node;

       sysctl_createv(clog, 0, NULL, &cnode, 0, CTLTYPE_NODE, "crypto",
           SYSCTL_DESCR("Kernel cryptography"),
           NULL, 0, NULL, 0,
           CTL_KERN, CTL_CREATE, CTL_EOL);
       sysctl_createv(clog, 0, &cnode, &chacha_node, 0, CTLTYPE_NODE, "chacha",
           SYSCTL_DESCR("ChaCha"),
           NULL, 0, NULL, 0,
           CTL_CREATE, CTL_EOL);
       sysctl_createv(clog, 0, &chacha_node, NULL,
           CTLFLAG_PERMANENT|CTLFLAG_READONLY, CTLTYPE_STRING, "selected",
           SYSCTL_DESCR("Selected ChaCha implementation"),
           sysctl_kern_crypto_chacha_selected, 0, NULL, 0,
           CTL_CREATE, CTL_EOL);
}

static int
chacha_select(void)
{

       if (chacha_md_impl) {
               if (chacha_selftest(chacha_md_impl))
                       aprint_error("chacha: self-test failed: %s\n",
                           chacha_md_impl->ci_name);
               else
                       chacha_impl = chacha_md_impl;
       }

       aprint_debug("chacha: %s\n", chacha_impl->ci_name);
       return 0;
}

MODULE(MODULE_CLASS_MISC, chacha, NULL);

static int
chacha_modcmd(modcmd_t cmd, void *opaque)
{

       switch (cmd) {
       case MODULE_CMD_INIT:
               return chacha_select();
       case MODULE_CMD_FINI:
               return 0;
       default:
               return ENOTTY;
       }
}

void
chacha_md_init(const struct chacha_impl *impl)
{

       KASSERT(cold);
       KASSERTMSG(chacha_md_impl == NULL,
           "ChaCha implementation `%s' already offered, can't offer `%s'",
           chacha_md_impl->ci_name, impl->ci_name);

       chacha_md_impl = impl;
}

void
chacha_core(uint8_t out[restrict static CHACHA_CORE_OUTBYTES],
   const uint8_t in[static CHACHA_CORE_INBYTES],
   const uint8_t k[static CHACHA_CORE_KEYBYTES],
   const uint8_t c[static CHACHA_CORE_CONSTBYTES],
   unsigned nr)
{

       (*chacha_impl->ci_chacha_core)(out, in, k, c, nr);
}

void
hchacha(uint8_t out[restrict static HCHACHA_OUTBYTES],
   const uint8_t in[static HCHACHA_INBYTES],
   const uint8_t k[static HCHACHA_KEYBYTES],
   const uint8_t c[static HCHACHA_CONSTBYTES],
   unsigned nr)
{

       (*chacha_impl->ci_hchacha)(out, in, k, c, nr);
}

void
chacha_stream(uint8_t *restrict s, size_t nbytes, uint32_t blkno,
   const uint8_t nonce[static CHACHA_STREAM_NONCEBYTES],
   const uint8_t key[static CHACHA_STREAM_KEYBYTES],
   unsigned nr)
{

       (*chacha_impl->ci_chacha_stream)(s, nbytes, blkno, nonce, key, nr);
}

void
chacha_stream_xor(uint8_t *c, const uint8_t *p, size_t nbytes, uint32_t blkno,
   const uint8_t nonce[static CHACHA_STREAM_NONCEBYTES],
   const uint8_t key[static CHACHA_STREAM_KEYBYTES],
   unsigned nr)
{

       (*chacha_impl->ci_chacha_stream_xor)(c, p, nbytes, blkno, nonce, key,
           nr);
}

void
xchacha_stream(uint8_t *restrict s, size_t nbytes, uint32_t blkno,
   const uint8_t nonce[static XCHACHA_STREAM_NONCEBYTES],
   const uint8_t key[static XCHACHA_STREAM_KEYBYTES],
   unsigned nr)
{

       (*chacha_impl->ci_xchacha_stream)(s, nbytes, blkno, nonce, key, nr);
}

void
xchacha_stream_xor(uint8_t *c, const uint8_t *p, size_t nbytes, uint32_t blkno,
   const uint8_t nonce[static XCHACHA_STREAM_NONCEBYTES],
   const uint8_t key[static XCHACHA_STREAM_KEYBYTES],
   unsigned nr)
{

       (*chacha_impl->ci_xchacha_stream_xor)(c, p, nbytes, blkno, nonce, key,
           nr);
}