Allow fixing invalid bip39 mnemonic

scripts/install-lethekit

@@ -1,5 +1,9 @@
 #!/bin/bash
 
+# Terminal colors
+RED=`tput setaf 1`
+RESET=`tput sgr0`
+
 git submodule update --init --recursive
 
 # usage: install-lethkit <lethkit-root> <arduino-sketchbook>
@@ -24,7 +28,7 @@ while (( "$#" )); do
       break
       ;;
     -*|--*=) # unsupported flags
-      echo "Error: Unsupported flag $1" >&2
+      echo "${RED}==Error: Unsupported flag $1 ==${RESET}" >&2
       exit 1
       ;;
     *) # preserve positional arguments
@@ -36,7 +40,7 @@ done
 
 if [ ${#args[@]} -ne 1 ]
 then
-    usage_error "must be 1 argument"
+    usage_error "${RED}== Error: must be 1 argument==${RESET}"
 fi
 
 echo "Note: Arduino sketchbook location is set in Arduino IDE: click File->Preferences"
@@ -72,7 +76,7 @@ libpath="${aroot}/libraries"
 # We need python to create libwally for arduino
 if ! python3 --version -v COMMAND &> /dev/null
 then
-    echo "Please, install python3."
+    echo "${RED}== Error: Please, install python3.==${RESET}"
     exit
 fi
 
@@ -91,8 +95,7 @@ popd
 # First, check if GxEPD2 is already installed (as a directory), warn
 # and stop in this case.
 gxepd2_path="${aroot}/libraries/GxEPD2"
-[ -d ${gxepd2_path} ] && ! [ -L ${gxepd2_path} ] && echo "GxEPD2 already installed in ${libpath}. Please remove it; we need to replace with SW SPI enabled version." && exit 1
-
+[ -d ${gxepd2_path} ] && ! [ -L ${gxepd2_path} ] && echo "${RED}== ERROR: GxEPD2 already installed in ${libpath}. Please remove it and re-run the last command==${RESET}" && exit 1
 declare -a libs=(
     ArduinoSTL
     bc-ur-arduino

seedtool/README.md

@@ -33,6 +33,10 @@ shares.
 
 ![BIP-39 Restore](doc/images/bip39-restore.png)
 
+When restoring BIP39 you can enter invalid BIP39 mnemonic sentence and have it fixed by LetheKit.
+
+![bad checkusm](doc/images/bip39_bad_checksum.png)
+
 ### SSKR Recovery
 
 If you possess enough shares of a SSKR set, you can recover the

seedtool/seed.h

@@ -61,6 +61,10 @@ class BIP39Seq {
     // Returns NULL if restore fails (bad BIP39 checksum).
     Seed * restore_seed() const;
 
+    // fix_bip39_checksum is only intended for when user wants
+    // to generate seed from bip39 words
+    void fix_bip39_checksum(void) { bip39_append_checksum(ctx); }
+
     // we need to have full menmonic words saved as string
     // which is needed to calculate mnemonic seed
     String get_mnemonic_as_string();

seedtool/seed.ino

@@ -159,8 +159,6 @@ uint8_t const * SSKRShareSeq::get_share(size_t ndx) const {
 }
 
 void SSKRShareSeq::set_share(size_t ndx, uint8_t const * share, size_t len) {
-    Serial.println("** **");
-    Serial.println(ndx); Serial.println(nshares);
     serial_assert(ndx < nshares);
     if (shares[ndx])
         free(shares[ndx]);
@@ -177,10 +175,6 @@ String SSKRShareSeq::get_share_strings(size_t ndx) const {
 Seed * SSKRShareSeq::restore_seed() const {
     uint8_t seed_data[Seed::SIZE];
 
-    Serial.println("restore seed");
-    Serial.println(bytes_in_each_share);
-    Serial.println(nshares);
-
     last_rv = sskr_combine(const_cast<const uint8_t **>(shares),
                              bytes_in_each_share,
                              nshares,
@@ -193,13 +187,13 @@ Seed * SSKRShareSeq::restore_seed() const {
 class CborListen : public CborListener {
   public:
     void OnInteger(int32_t value){ };
-    void OnBytes(unsigned char *data, unsigned int size) {Serial.println("bytes"); memcpy(bytes, data, size); len = size;};
+    void OnBytes(unsigned char *data, unsigned int size) { memcpy(bytes, data, size); len = size; };
     void OnString(String &str) {};
     void OnArray(unsigned int size) {};
     void OnMap(unsigned int size) {};
     void OnTag(uint32_t tag) { tag_ = tag; };
-    void OnSpecial(uint32_t code) {Serial.println("tag");};
-    void OnError(const char *error) {Serial.println("error");};
+    void OnSpecial(uint32_t code) {};
+    void OnError(const char *error) {};
 
     // we are gonna collect the tag and bytes
     uint32_t tag_;

seedtool/userinterface.ino

@@ -496,6 +496,15 @@ void seedless_menu() {
     }
 }
 
+void pendingCallback(const void*)
+{
+  String txt = "One moment...";
+  Point p = text_center(txt.c_str());
+  g_display->fillScreen(GxEPD_WHITE);
+  g_display->setCursor(p.x, p.y);
+  g_display->println(txt);
+}
+
 void generate_seed() {
     while (true) {
         int xoff = 14;
@@ -591,7 +600,7 @@ void generate_seed() {
             // This will take a few seconds; clear the screen
             // immediately to let the user know something is
             // happening ..
-            full_window_clear();
+            g_display->drawPaged(pendingCallback, 0);
 
             if (g_bip39)
                 delete g_bip39;
@@ -1365,7 +1374,51 @@ struct BIP39WordlistState : WordListState {
     }
 };
 
+
+// returns true if user wants bad checksum to get automatically fixed
+// returns false if user wants to correct the mistake by himself
+bool invalid_bip39_checksum(void) {
+
+    int xoff = 6;
+    int yoff = 6;
+
+    g_display->firstPage();
+    do
+    {
+        g_display->setPartialWindow(0, 0, 200, 200);
+        // g_display->fillScreen(GxEPD_WHITE);
+        g_display->setTextColor(GxEPD_BLACK);
+
+        int xx = xoff;
+        int yy = yoff + (H_FSB9 + YM_FSB9);
+        g_display->setFont(&FreeSansBold9pt7b);
+        g_display->setCursor(xx, yy);
+        display_printf("Bip39 bad checksum");
+        yy += H_FSB9 + YM_FSB9+20;
+
+        display_long_text(yy, "Press # to check your words again", 22);
+        display_long_text(yy+70, "Press A to fix the checksum", 19);
+    }
+    while (g_display->nextPage());
+
+    while (true) {
+        char key;
+        do {
+            key = g_keypad.getKey();
+        } while (key == NO_KEY);
+        switch (key) {
+        case '#':
+            return false;
+        case 'A':
+            return true;
+        default:
+            break;
+        }
+    }
+}
+
 void restore_bip39() {
+    bool fix_checksum = false;
     BIP39WordlistState state(g_bip39, BIP39Seq::WORD_COUNT);
     state.set_words((uint16_t *)NULL);
 
@@ -1493,6 +1546,7 @@ void restore_bip39() {
             break;
         case '#':	// done
             {
+                g_display->drawPaged(pendingCallback, 0);
                 uint16_t bip39_words[BIP39Seq::WORD_COUNT];
                 for (size_t ii = 0; ii < BIP39Seq::WORD_COUNT; ++ii)
                     bip39_words[ii] = state.wordndx[ii];
@@ -1508,17 +1562,13 @@ void restore_bip39() {
                     g_uistate = SEEDY_MENU;
                     return;
                 } else {
+                    fix_checksum = invalid_bip39_checksum();
+                    if (fix_checksum) {
+                        bip39->fix_bip39_checksum();
+                        for (size_t ii = 0; ii < BIP39Seq::WORD_COUNT; ++ii)
+                            state.wordndx[ii] = bip39->get_word(ii);
+                    }
                     delete bip39;
-                    String lines[7];
-                    size_t nlines = 0;
-                    lines[nlines++] = "BIP39 Word List";
-                    lines[nlines++] = "Checksum Error";
-                    lines[nlines++] = "";
-                    lines[nlines++] = "Check your word";
-                    lines[nlines++] = "list carefully";
-                    lines[nlines++] = "";
-                    lines[nlines++] = "Press # to revisit";
-                    interstitial_error(lines, nlines);
                 }
                 break;
             }