diff options
Diffstat (limited to 'sys/dev/random/random.c')
-rw-r--r-- | sys/dev/random/random.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/sys/dev/random/random.c b/sys/dev/random/random.c new file mode 100644 index 0000000..d79df69 --- /dev/null +++ b/sys/dev/random/random.c @@ -0,0 +1,88 @@ +/* + * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team. + * 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. + * 3. Neither the name of Hyra nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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/sio.h> +#include <sys/device.h> +#include <sys/driver.h> +#include <dev/random/chacha20.h> +#include <dev/random/siphash.h> +#include <dev/random/entropy.h> +#include <fs/devfs.h> +#include <string.h> + +static struct cdevsw random_cdevsw; +static struct entropy_pool entropy; + +uint8_t key[32] = {0}; +uint8_t nonce[12] = {0}; +uint32_t state[16]; +uint32_t tsc; + +static inline uint64_t +read_tsc(void) +{ + uint32_t lo, hi; + __asm__ volatile ("rdtsc" : "=a"(lo), "=d"(hi)); + return ((uint64_t)hi << 32) | lo; +} + +static int +random_read(dev_t dev, struct sio_txn *sio, int flags) +{ + tsc = read_tsc(); + mix_entropy(&entropy, (uint8_t *)&tsc, sizeof(tsc), 1); + + chacha20_init(state, entropy.pool, nonce, 0); + chacha20_encrypt(state, NULL, sio->buf, sio->len); + + return sio->len; +} + +static int +random_init(void) +{ + char devname[] = "random"; + devmajor_t major; + dev_t dev; + + /* Register the device here */ + major = dev_alloc_major(); + dev = dev_alloc(major); + dev_register(major, dev, &random_cdevsw); + devfs_create_entry(devname, major, dev, 0444); + + return 0; +} + +static struct cdevsw random_cdevsw = { + .read = random_read, + .write = nowrite +}; + +DRIVER_EXPORT(random_init, "random"); |