Kernel: Harvest randomness from various drivers

Random now gets entropy from the following drivers:
- KeyboardDevice
- PATAChannel
- PS2MouseDevice
- E1000NetworkAdapter
- RTL8139NetworkAdapter

Of these devices,  PS2MouseDevice and PATAChannel provide the vast
majority of the entropy.

Kernel/Devices/KeyboardDevice.cpp

@@ -287,6 +287,8 @@ void KeyboardDevice::handle_irq(const RegisterState&)
         u8 ch = raw & 0x7f;
         bool pressed = !(raw & 0x80);
 
+        m_entropy_source.add_random_event(raw);
+
         if (raw == 0xe0) {
             m_has_e0_prefix = true;
             return;

Kernel/Devices/KeyboardDevice.h

@@ -32,6 +32,7 @@
 #include <Kernel/Devices/CharacterDevice.h>
 #include <Kernel/Interrupts/IRQHandler.h>
 #include <Kernel/KeyCode.h>
+#include <Kernel/Random.h>
 #include <LibKeyboard/CharacterMap.h>
 
 namespace Kernel {
@@ -82,6 +83,7 @@ private:
     bool m_caps_lock_on { false };
     bool m_num_lock_on { false };
     bool m_has_e0_prefix { false };
+    EntropySource m_entropy_source;
 
     Keyboard::CharacterMap m_character_map = Keyboard::CharacterMap("en");
 };

Kernel/Devices/PATAChannel.cpp

@@ -29,9 +29,9 @@
 #include <Kernel/Devices/PATAChannel.h>
 #include <Kernel/Devices/PATADiskDevice.h>
 #include <Kernel/FileSystem/ProcFS.h>
+#include <Kernel/IO.h>
 #include <Kernel/Process.h>
 #include <Kernel/VM/MemoryManager.h>
-#include <Kernel/IO.h>
 
 namespace Kernel {
 
@@ -186,6 +186,9 @@ void PATAChannel::handle_irq(const RegisterState&)
     // FIXME: We might get random interrupts due to malfunctioning hardware, so we should check that we actually requested something to happen.
 
     u8 status = m_io_base.offset(ATA_REG_STATUS).in<u8>();
+
+    m_entropy_source.add_random_event(status);
+
     if (status & ATA_SR_ERR) {
         print_ide_status(status);
         m_device_error = m_io_base.offset(ATA_REG_ERROR).in<u8>();

Kernel/Devices/PATAChannel.h

@@ -44,6 +44,7 @@
 #include <Kernel/PCI/Access.h>
 #include <Kernel/PCI/Device.h>
 #include <Kernel/PhysicalAddress.h>
+#include <Kernel/Random.h>
 #include <Kernel/VM/PhysicalPage.h>
 #include <Kernel/WaitQueue.h>
 
@@ -103,6 +104,7 @@ private:
     RefPtr<PhysicalPage> m_dma_buffer_page;
     IOAddress m_bus_master_base;
     Lockable<bool> m_dma_enabled;
+    EntropySource m_entropy_source;
 
     RefPtr<PATADiskDevice> m_master;
     RefPtr<PATADiskDevice> m_slave;

Kernel/Devices/PS2MouseDevice.cpp

@@ -81,6 +81,7 @@ void PS2MouseDevice::handle_irq(const RegisterState&)
         if (backdoor->vmmouse_is_absolute()) {
             IO::in8(I8042_BUFFER);
             auto packet = backdoor->receive_mouse_packet();
+            m_entropy_source.add_random_event(packet);
             if (packet.has_value())
                 m_queue.enqueue(packet.value());
             return;
@@ -99,6 +100,8 @@ void PS2MouseDevice::handle_irq(const RegisterState&)
 #ifdef PS2MOUSE_DEBUG
             dbg() << "PS2Mouse: " << m_data[1] << ", " << m_data[2] << " " << ((m_data[0] & 1) ? "Left" : "") << " " << ((m_data[0] & 2) ? "Right" : "") << " (buffered: " << m_queue.size() << ")";
 #endif
+            m_entropy_source.add_random_event(*(u32*)m_data);
+
             parse_data_packet();
         };
 

Kernel/Devices/PS2MouseDevice.h

@@ -30,6 +30,7 @@
 #include <Kernel/Devices/CharacterDevice.h>
 #include <Kernel/Interrupts/IRQHandler.h>
 #include <Kernel/MousePacket.h>
+#include <Kernel/Random.h>
 
 namespace Kernel {
 
@@ -77,6 +78,7 @@ private:
     u8 m_data[4];
     bool m_has_wheel { false };
     bool m_has_five_buttons { false };
+    EntropySource m_entropy_source;
 };
 
 }