From 8a9208612eec8ddae4c418485d848ecfa0613699 Mon Sep 17 00:00:00 2001
From: Anton Kling <anton@kling.gg>
Date: Mon, 30 Oct 2023 22:12:14 +0100
Subject: Meta: Move kernel and userland to their own folders.

This is to allow both the kernel and the userland to share certain
header files and to make the folder structure a bit more clear.
---
 random.c | 142 ---------------------------------------------------------------
 1 file changed, 142 deletions(-)
 delete mode 100644 random.c

(limited to 'random.c')

diff --git a/random.c b/random.c
deleted file mode 100644
index 0e1b760..0000000
--- a/random.c
+++ /dev/null
@@ -1,142 +0,0 @@
-// FIXME: This is mostlikely incredibly inefficent and insecure.
-#include <crypto/ChaCha20/chacha20.h>
-#include <crypto/SHA1/sha1.h>
-#include <fs/devfs.h>
-#include <fs/vfs.h>
-#include <random.h>
-#include <stddef.h>
-#include <string.h>
-
-#define HASH_CTX SHA1_CTX
-#define HASH_LEN SHA1_LEN
-
-uint32_t internal_chacha_block[16] = {
-    // Constant ascii values of "expand 32-byte k"
-    0x61707865,
-    0x3320646e,
-    0x79622d32,
-    0x6b206574,
-    // The unique key
-    0x00000000,
-    0x00000000,
-    0x00000000,
-    0x00000000,
-    0x00000000,
-    0x00000000,
-    0x00000000,
-    0x00000000,
-    // Block counter
-    0x00000000,
-    // Nonce
-    0x00000000,
-    0x00000000,
-};
-
-void mix_chacha(void) {
-  uint8_t rand_data[BLOCK_SIZE];
-  get_random((BYTEPTR)rand_data, BLOCK_SIZE);
-  memcpy(internal_chacha_block + KEY, rand_data, KEY_SIZE);
-  memcpy(internal_chacha_block + NONCE, rand_data + KEY_SIZE, NONCE_SIZE);
-  internal_chacha_block[COUNT] = 0;
-}
-
-void get_random(BYTEPTR buffer, uint64_t len) {
-  uint8_t rand_data[BLOCK_SIZE];
-  for (; len > 0;) {
-    if (COUNT_MAX - 1 == internal_chacha_block[COUNT]) {
-      // The current block has used up all the 2^32 counts. If the
-      // key and/or the nonce are not changed and the count
-      // overflows back to zero then the random values would
-      // repeate. This is of course not desiered behaviour. The
-      // solution is to create a new nonce and key using the
-      // already established chacha block.
-      internal_chacha_block[COUNT]++;
-      mix_chacha();
-    }
-    uint32_t read_len = (BLOCK_SIZE < len) ? (BLOCK_SIZE) : len;
-    chacha_block((uint32_t *)rand_data, internal_chacha_block);
-    internal_chacha_block[COUNT]++;
-    memcpy(buffer, rand_data, read_len);
-    buffer += read_len;
-    len -= read_len;
-  }
-}
-
-HASH_CTX hash_pool;
-uint32_t hash_pool_size = 0;
-
-void add_hash_pool(void) {
-  uint8_t new_chacha_key[KEY_SIZE];
-  get_random(new_chacha_key, KEY_SIZE);
-
-  uint8_t hash_buffer[HASH_LEN];
-  SHA1_Final(&hash_pool, hash_buffer);
-  for (size_t i = 0; i < HASH_LEN; i++)
-    new_chacha_key[i % KEY_SIZE] ^= hash_buffer[i];
-
-  SHA1_Init(&hash_pool);
-  SHA1_Update(&hash_pool, hash_buffer, HASH_LEN);
-
-  uint8_t block[BLOCK_SIZE];
-  get_random(block, BLOCK_SIZE);
-  SHA1_Update(&hash_pool, block, BLOCK_SIZE);
-
-  memcpy(internal_chacha_block + KEY, new_chacha_key, KEY_SIZE);
-
-  mix_chacha();
-}
-
-void add_entropy(uint8_t *buffer, size_t size) {
-  SHA1_Update(&hash_pool, buffer, size);
-  hash_pool_size += size;
-  if (hash_pool_size >= HASH_LEN * 2)
-    add_hash_pool();
-}
-
-void setup_random(void) {
-  SHA1_Init(&hash_pool);
-
-  BYTE seed[1024];
-  int rand_fd = vfs_open("/etc/seed", O_RDWR, 0);
-  if (0 > rand_fd) {
-    klog("/etc/seed not found", LOG_WARN);
-    return;
-  }
-
-  size_t offset = 0;
-  for (int rc; (rc = vfs_pread(rand_fd, seed, 1024, offset)); offset += rc) {
-    if (0 > rc) {
-      klog("/etc/seed read error", LOG_WARN);
-      break;
-    }
-    add_entropy(seed, rc);
-  }
-  add_hash_pool();
-
-  // Update the /etc/seed file to ensure we get a new state upon next
-  // boot.
-  get_random(seed, 1024);
-  vfs_pwrite(rand_fd, seed, 1024, 0);
-  vfs_close(rand_fd);
-}
-
-int random_write(BYTEPTR buffer, uint64_t offset, uint64_t len, vfs_fd_t *fd) {
-  (void)offset;
-  (void)fd;
-  add_entropy(buffer, len);
-  return len; // add_entropy() never fails to recieve (len) amount of data.
-}
-
-int random_read(BYTEPTR buffer, uint64_t offset, uint64_t len, vfs_fd_t *fd) {
-  (void)offset;
-  (void)fd;
-  get_random(buffer, len);
-  return len; // get_random() never fails to give "len" amount of data.
-}
-
-void add_random_devices(void) {
-  devfs_add_file("/random", random_read, random_write, NULL, 1, 1,
-                 FS_TYPE_CHAR_DEVICE);
-  devfs_add_file("/urandom", random_read, random_write, NULL, 1, 1,
-                 FS_TYPE_CHAR_DEVICE);
-}
-- 
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