Kb privacy rng

src/board/system76/common/include/board/options.h

@@ -24,6 +24,8 @@ enum {
     OPT_ALLOW_BAT_BOOST,
     OPT_ALWAYS_ON_USB,
     OPT_GPU_MUX_CTRL,
+    OPT_KB_PRIVACY,
+    OPT_KB_PRIVACY_MAX_DELAY_MS,
     NUM_OPTIONS
 };
 

src/board/system76/common/kbc.c

@@ -1,11 +1,14 @@
 // SPDX-License-Identifier: GPL-3.0-only
 
+#include "include/board/options.h"
 #include <arch/delay.h>
+#include <arch/time.h>
 #include <board/kbc.h>
 #include <board/kbscan.h>
 #include <board/keymap.h>
 #include <common/debug.h>
 #include <common/macro.h>
+#include <common/rng.h>
 #include <ec/espi.h>
 #include <ec/ps2.h>
 
@@ -80,10 +83,14 @@ static const uint16_t kbc_typematic_period[32] = {
 };
 // clang-format on
 
-static uint8_t kbc_buffer[16] = { 0 };
+static uint8_t kbc_buffer[32] = { 0 };
 static uint8_t kbc_buffer_head = 0;
 static uint8_t kbc_buffer_tail = 0;
 
+static bool kbc_buffer_privacy = false;
+static uint32_t kbc_buffer_privacy_last_time = 0;
+static uint16_t kbc_buffer_privacy_delay = 0;
+
 static bool kbc_buffer_pop(uint8_t *scancode) {
     if (kbc_buffer_head == kbc_buffer_tail) {
         return false;
@@ -459,8 +466,23 @@ void kbc_event(struct Kbc *kbc) {
     uint8_t sts;
 
     // Read from scancode buffer when possible
-    if (state == KBC_STATE_NORMAL && kbc_buffer_pop(&state_data)) {
-        state = KBC_STATE_KEYBOARD;
+    if (state == KBC_STATE_NORMAL) {
+        if (options_get(OPT_KB_PRIVACY)) {
+            uint32_t time = time_get();
+            if (time - kbc_buffer_privacy_last_time >= (uint32_t)kbc_buffer_privacy_delay) {
+                TRACE("KB_Priv: delay of %d passed\n", kbc_buffer_privacy_delay);
+                if (kbc_buffer_pop(&state_data)) {
+                    state = KBC_STATE_KEYBOARD;
+                    kbc_buffer_privacy_last_time = time;
+                    kbc_buffer_privacy_delay = (uint16_t)(nondeterministic_rng() %
+                                                          options_get(OPT_KB_PRIVACY_MAX_DELAY_MS));
+                }
+            }
+        } else {
+            if (kbc_buffer_pop(&state_data)) {
+                state = KBC_STATE_KEYBOARD;
+            }
+        }
     }
 
     // Read from touchpad when possible
@@ -521,3 +543,7 @@ void kbc_event(struct Kbc *kbc) {
         kbc_on_output_empty(kbc);
     }
 }
+
+void kbc_toggle_delay_randomization() {
+    options_set(OPT_KB_PRIVACY, options_get(OPT_KB_PRIVACY) ^ 1);
+}

src/board/system76/common/kbscan.c

@@ -14,6 +14,7 @@
 #include <board/power.h>
 #include <common/macro.h>
 #include <common/debug.h>
+#include <common/rng.h>
 
 // Default to not n-key rollover
 #ifndef KM_NKEY
@@ -202,6 +203,13 @@ bool kbscan_press(uint16_t key, bool pressed, uint8_t *layer) {
         pmc_swi();
     }
 
+    if (key == K_KB_PRIVACY && pressed) {
+        DEBUG("Toggling keyboard privacy\n");
+        rng_seed(time_get());
+        kbc_toggle_delay_randomization();
+        return true;
+    }
+
     if (key == K_FNLOCK && pressed) {
         DEBUG("Toggling FnLock\n");
         keymap_fnlock ^= 1;
@@ -316,6 +324,7 @@ static inline bool key_should_repeat(uint16_t key) {
     case K_CAMERA_TOGGLE:
     case K_DISPLAY_TOGGLE:
     case K_FAN_TOGGLE:
+    case K_KB_PRIVACY:
     case K_KBD_BKL:
     case K_KBD_COLOR:
     case K_KBD_TOGGLE:

src/board/system76/common/options.c

@@ -17,6 +17,8 @@ uint8_t DEFAULT_OPTIONS[NUM_OPTIONS] = {
     [OPT_ALLOW_BAT_BOOST] = 0,
     [OPT_ALWAYS_ON_USB] = 0,
     [OPT_GPU_MUX_CTRL] = 0,
+    [OPT_KB_PRIVACY] = 0,
+    [OPT_KB_PRIVACY_MAX_DELAY_MS] = 100,
 };
 // clang-format on
 

src/common/common.mk

@@ -3,3 +3,4 @@
 common-y += i2c.c
 common-y += keymap.c
 common-y += version.c
+common-y += rng.c

src/common/include/common/keymap.h

@@ -284,5 +284,6 @@ uint16_t keymap_translate(uint16_t key);
 
 #define KF_CUSTOM (0x0200)
 #define K_FNLOCK (KF_CUSTOM | 0x01)
+#define K_KB_PRIVACY (KF_CUSTOM | 0x02)
 
 #endif // _COMMON_KEYMAP_H

src/common/include/common/rng.h

@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: GPL-3.0-only
+
+#ifndef _COMMON_RNG_H
+#define _COMMON_RNG_H
+
+#include <stdint.h>
+
+void rng_seed(uint16_t seed);
+uint16_t simple_rng(void);
+uint16_t nondeterministic_rng(void);
+
+#endif

src/common/rng.c

@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-3.0-only
+//
+#include <common/rng.h>
+#include <arch/time.h>
+
+#define LFSR_MASK 0xB400u
+
+static uint16_t simple_rng_reg = -1U;
+static uint16_t nondeterministic_rng_reg = -1U;
+
+void rng_seed(uint16_t seed) {
+    // 0 is invalid state, the generator locks up on 0
+    uint16_t s = seed ? seed : -1U;
+    simple_rng_reg = s;
+    nondeterministic_rng_reg = s;
+}
+
+uint16_t _galois_fsr(uint16_t lfsr) {
+    uint16_t bit = lfsr & 1U;
+    lfsr >>= 1U;
+    if (bit) {
+        lfsr ^= LFSR_MASK;
+    }
+    return lfsr;
+}
+
+uint16_t simple_rng(void) {
+    simple_rng_reg = _galois_fsr(simple_rng_reg);
+    return simple_rng_reg;
+}
+
+uint16_t nondeterministic_rng(void) {
+    nondeterministic_rng_reg += (uint16_t)(time_get());
+    nondeterministic_rng_reg = _galois_fsr(nondeterministic_rng_reg);
+    return nondeterministic_rng_reg;
+}

src/ec/ite/include/ec/kbc.h

@@ -35,7 +35,7 @@ uint8_t kbc_status(struct Kbc *kbc);
 uint8_t kbc_read(struct Kbc *kbc);
 bool kbc_keyboard(struct Kbc *kbc, uint8_t data, uint16_t timeout);
 bool kbc_mouse(struct Kbc *kbc, uint8_t data, uint16_t timeout);
-
+void kbc_toggle_delay_randomization();
 volatile uint8_t __xdata __at(0x1300) KBHICR;
 volatile uint8_t __xdata __at(0x1302) KBIRQR;
 volatile uint8_t __xdata __at(0x1304) KBHISR;

src/keyboard/system76/14in_83/keymap/combo_iso_ansi.c

@@ -17,9 +17,9 @@ LAYOUT_ISO(
 ),
 LAYOUT_ISO(
     K_ESC, K_TOUCHPAD, K_DISPLAY_TOGGLE, K_MUTE, K_KBD_BKL, K_VOLUME_DOWN, K_VOLUME_UP, K_DISPLAY_MODE, K_BRIGHTNESS_DOWN, K_BRIGHTNESS_UP, K_CAMERA_TOGGLE, K_AIRPLANE_MODE, K_SUSPEND, K_PRINT_SCREEN, K_PAUSE, K_NUM_LOCK, K_SCROLL_LOCK,
-    K_PLAY_PAUSE, K_FAN_TOGGLE, K_2, K_3, K_4, K_5, K_6, K_NUM_7, K_NUM_8, K_NUM_9, K_NUM_ASTERISK, K_MINUS, K_EQUALS, K_BKSP,
+    K_PLAY_PAUSE, K_FAN_TOGGLE, K_2, K_3, K_MIC_MUTE, K_5, K_6, K_NUM_7, K_NUM_8, K_NUM_9, K_NUM_ASTERISK, K_MINUS, K_EQUALS, K_BKSP,
     K_TAB, K_Q, K_W, K_E, K_R, K_T, K_Y, K_NUM_4, K_NUM_5, K_NUM_6, K_NUM_SLASH, K_BRACE_OPEN, K_BRACE_CLOSE, K_ENTER,
-    K_FNLOCK, K_A, K_S, K_D, K_F, K_G, K_H, K_NUM_1, K_NUM_2, K_NUM_3, K_NUM_MINUS, K_QUOTE, K_BACKSLASH,
+    K_FNLOCK, K_A, K_KB_PRIVACY, K_D, K_F, K_G, K_H, K_NUM_1, K_NUM_2, K_NUM_3, K_NUM_MINUS, K_QUOTE, K_BACKSLASH,
     K_LEFT_SHIFT, K_INT_1, K_Z, K_X, K_C, K_V, K_B, K_N, K_NUM_0, K_COMMA, K_NUM_PERIOD, K_NUM_PLUS, K_RIGHT_SHIFT,
     K_LEFT_CTRL, KT_FN, K_LEFT_SUPER, K_LEFT_ALT, K_SPACE, K_RIGHT_ALT, K_APP, K_HOME, K_UP, K_END,
     K_LEFT, K_DOWN, K_RIGHT

src/keyboard/system76/14in_83/keymap/combo_iso_ansi_micmute.c

@@ -19,7 +19,7 @@ LAYOUT_ISO(
     K_ESC, K_TOUCHPAD, K_DISPLAY_TOGGLE, K_MUTE, K_KBD_BKL, K_VOLUME_DOWN, K_VOLUME_UP, K_DISPLAY_MODE, K_BRIGHTNESS_DOWN, K_BRIGHTNESS_UP, K_CAMERA_TOGGLE, K_AIRPLANE_MODE, K_SUSPEND, K_PRINT_SCREEN, K_PAUSE, K_NUM_LOCK, K_SCROLL_LOCK,
     K_PLAY_PAUSE, K_FAN_TOGGLE, K_2, K_3, K_MIC_MUTE, K_5, K_6, K_NUM_7, K_NUM_8, K_NUM_9, K_NUM_ASTERISK, K_MINUS, K_EQUALS, K_BKSP,
     K_TAB, K_Q, K_W, K_E, K_R, K_T, K_Y, K_NUM_4, K_NUM_5, K_NUM_6, K_NUM_SLASH, K_BRACE_OPEN, K_BRACE_CLOSE, K_ENTER,
-    K_FNLOCK, K_A, K_S, K_D, K_F, K_G, K_H, K_NUM_1, K_NUM_2, K_NUM_3, K_NUM_MINUS, K_QUOTE, K_BACKSLASH,
+    K_FNLOCK, K_A, K_KB_PRIVACY, K_D, K_F, K_G, K_H, K_NUM_1, K_NUM_2, K_NUM_3, K_NUM_MINUS, K_QUOTE, K_BACKSLASH,
     K_LEFT_SHIFT, K_INT_1, K_Z, K_X, K_C, K_V, K_B, K_N, K_NUM_0, K_COMMA, K_NUM_PERIOD, K_NUM_PLUS, K_RIGHT_SHIFT,
     K_LEFT_CTRL, KT_FN, K_LEFT_SUPER, K_LEFT_ALT, K_SPACE, K_RIGHT_ALT, K_APP, K_HOME, K_UP, K_END,
     K_LEFT, K_DOWN, K_RIGHT

src/keyboard/system76/15in_102/keymap/default.c

@@ -18,7 +18,7 @@ LAYOUT(
     K_ESC, K_TOUCHPAD, K_DISPLAY_TOGGLE, K_MUTE, K_F4, K_VOLUME_DOWN, K_VOLUME_UP, K_DISPLAY_MODE, K_BRIGHTNESS_DOWN, K_BRIGHTNESS_UP, K_CAMERA_TOGGLE, K_AIRPLANE_MODE, K_SUSPEND, K_PRINT_SCREEN, K_SCROLL_LOCK, K_DEL, K_HOME, K_END, K_PAUSE, K_PAUSE,
     K_PLAY_PAUSE, K_FAN_TOGGLE, K_2, K_3, K_4, K_5, K_6, K_7, K_8, K_9, K_0, K_MINUS, K_EQUALS, K_BKSP, K_NUM_LOCK, K_KBD_COLOR, K_KBD_TOGGLE, K_KBD_DOWN,
     K_TAB, K_Q, K_W, K_E, K_R, K_T, K_Y, K_U, K_I, K_O, K_P, K_BRACE_OPEN, K_BRACE_CLOSE, K_BACKSLASH, K_NUM_7, K_NUM_8, K_NUM_9, K_KBD_UP,
-    K_FNLOCK, K_A, K_S, K_D, K_F, K_G, K_H, K_J, K_K, K_L, K_SEMICOLON, K_QUOTE, K_ENTER, K_NUM_4, K_NUM_5, K_NUM_6,
+    K_FNLOCK, K_A, K_KB_PRIVACY, K_D, K_F, K_G, K_H, K_J, K_K, K_L, K_SEMICOLON, K_QUOTE, K_ENTER, K_NUM_4, K_NUM_5, K_NUM_6,
     K_LEFT_SHIFT, K_Z, K_X, K_C, K_V, K_B, K_N, K_M, K_COMMA, K_PERIOD, K_SLASH, K_RIGHT_SHIFT, K_UP, K_NUM_1, K_NUM_2, K_NUM_3, K_NUM_ENTER,
     K_LEFT_CTRL, KT_FN, K_LEFT_SUPER, K_LEFT_ALT, K_SPACE, K_RIGHT_ALT, K_APP, K_RIGHT_CTRL, K_LEFT, K_DOWN, K_RIGHT, K_NUM_0, K_NUM_PERIOD
 )