EIP-191 clear signing

src_features/signMessage/cmd_signMessage.c

@@ -1,3 +1,4 @@
+#include <stdbool.h>
 #include "shared_context.h"
 #include "apdu_constants.h"
 #include "utils.h"
@@ -7,12 +8,108 @@ static const char SIGN_MAGIC[] =
     "\x19"
     "Ethereum Signed Message:\n";
 
+/**
+ * Check if a given character is a "special" displayable ASCII character
+ *
+ * @param[in] c character we're checking
+ * @return wether the character is special or not
+ */
+static inline bool is_char_special(char c) {
+    return ((c >= '\b') && (c <= '\r'));
+}
+
+/**
+ * Check if a given data is made of ASCII characters
+ *
+ * @param[in] data the input data
+ * @param[in] the length of the input data
+ * @return wether the data is fully ASCII or not
+ */
+static bool is_data_ascii(const uint8_t *const data, uint8_t length) {
+    for (uint8_t idx = 0; idx < length; ++idx) {
+        if (!is_char_special(data[idx]) && ((data[idx] < 0x20) || (data[idx] > 0x7e))) {
+            return false;
+        }
+    }
+    return true;
+}
+
+/**
+ * Initialize value string that will be displayed in the UX STEP
+ *
+ * @param[in] if the value is ASCII
+ */
+static void init_value_str(bool is_ascii) {
+    if (is_ascii) {
+        strings.tmp.tmp[0] = '\0';  // init string as empty
+    } else {
+        strcpy(strings.tmp.tmp, "0x");  // will display the hex bytes instead
+    }
+}
+
+/**
+ * Update the global UI string variable by formatting & appending the new data to it
+ *
+ * @param[in] data the input data
+ * @param[in] length the data length
+ * @param[in] is_ascii wether the data is ASCII or not
+ */
+static void feed_value_str(const uint8_t *const data, uint8_t length, bool is_ascii) {
+    uint16_t value_strlen = strlen(strings.tmp.tmp);
+
+    if ((value_strlen + 1) < sizeof(strings.tmp.tmp)) {
+        if (is_ascii) {
+            uint8_t src_idx = 0;
+            uint16_t dst_idx = value_strlen;
+            bool prev_is_special = false;
+
+            while ((src_idx < length) && (dst_idx < sizeof(strings.tmp.tmp))) {
+                if (prev_is_special) {
+                    if (!is_char_special(data[src_idx])) {
+                        prev_is_special = false;
+                    }
+                } else {
+                    if (is_char_special(data[src_idx])) {
+                        prev_is_special = true;
+                        strings.tmp.tmp[dst_idx] = ' ';
+                        dst_idx += 1;
+                    }
+                }
+                if (!is_char_special(data[src_idx])) {
+                    strings.tmp.tmp[dst_idx] = data[src_idx];
+                    dst_idx += 1;
+                }
+                src_idx += 1;
+            }
+
+            if (dst_idx < sizeof(strings.tmp.tmp)) {
+                strings.tmp.tmp[dst_idx] = '\0';
+            } else {
+                const char marker[] = "...";
+
+                memcpy(strings.tmp.tmp + sizeof(strings.tmp.tmp) - sizeof(marker),
+                       marker,
+                       sizeof(marker));
+            }
+        } else {
+            snprintf(strings.tmp.tmp + value_strlen,
+                     sizeof(strings.tmp.tmp) - value_strlen,
+                     "%.*H",
+                     length,
+                     data);
+        }
+    }
+}
+
 void handleSignPersonalMessage(uint8_t p1,
                                uint8_t p2,
                                uint8_t *workBuffer,
                                uint16_t dataLength,
                                unsigned int *flags,
                                unsigned int *tx) {
+    // Point to this unused global variable for persistency
+    bool *is_ascii = (bool *) &strings.tmp.tmp2[0];
+
     UNUSED(tx);
     uint8_t hashMessage[INT256_LENGTH];
     if (p1 == P1_FIRST) {
@@ -29,6 +126,7 @@ void handleSignPersonalMessage(uint8_t p1,
             reset_app_context();
         }
         appState = APP_STATE_SIGNING_MESSAGE;
+
         tmpCtx.messageSigningContext.pathLength = workBuffer[0];
         if ((tmpCtx.messageSigningContext.pathLength < 0x01) ||
             (tmpCtx.messageSigningContext.pathLength > MAX_BIP32_PATH)) {
@@ -38,21 +136,21 @@ void handleSignPersonalMessage(uint8_t p1,
         workBuffer++;
         dataLength--;
         for (i = 0; i < tmpCtx.messageSigningContext.pathLength; i++) {
-            if (dataLength < 4) {
+            if (dataLength < sizeof(uint32_t)) {
                 PRINTF("Invalid data\n");
                 THROW(0x6a80);
             }
             tmpCtx.messageSigningContext.bip32Path[i] = U4BE(workBuffer, 0);
-            workBuffer += 4;
+            workBuffer += sizeof(uint32_t);
-            dataLength -= 4;
+            dataLength -= sizeof(uint32_t);
         }
-        if (dataLength < 4) {
+        if (dataLength < sizeof(uint32_t)) {
             PRINTF("Invalid data\n");
             THROW(0x6a80);
         }
         tmpCtx.messageSigningContext.remainingLength = U4BE(workBuffer, 0);
-        workBuffer += 4;
+        workBuffer += sizeof(uint32_t);
-        dataLength -= 4;
+        dataLength -= sizeof(uint32_t);
         // Initialize message header + length
         cx_keccak_init(&global_sha3, 256);
         cx_hash((cx_hash_t *) &global_sha3,
@@ -71,6 +169,10 @@ void handleSignPersonalMessage(uint8_t p1,
         tmp[pos] = '\0';
         cx_hash((cx_hash_t *) &global_sha3, 0, (uint8_t *) tmp, pos, NULL, 0);
         cx_sha256_init(&tmpContent.sha2);
+
+        *is_ascii = is_data_ascii(workBuffer, dataLength);
+        init_value_str(*is_ascii);
+
     } else if (p1 != P1_MORE) {
         THROW(0x6B00);
     }
@@ -84,9 +186,13 @@ void handleSignPersonalMessage(uint8_t p1,
     if (dataLength > tmpCtx.messageSigningContext.remainingLength) {
         THROW(0x6A80);
     }
+
     cx_hash((cx_hash_t *) &global_sha3, 0, workBuffer, dataLength, NULL, 0);
     cx_hash((cx_hash_t *) &tmpContent.sha2, 0, workBuffer, dataLength, NULL, 0);
     tmpCtx.messageSigningContext.remainingLength -= dataLength;
+
+    feed_value_str(workBuffer, dataLength, *is_ascii);
+
     if (tmpCtx.messageSigningContext.remainingLength == 0) {
         cx_hash((cx_hash_t *) &global_sha3,
                 CX_LAST,
@@ -95,11 +201,6 @@ void handleSignPersonalMessage(uint8_t p1,
                 tmpCtx.messageSigningContext.hash,
                 32);
         cx_hash((cx_hash_t *) &tmpContent.sha2, CX_LAST, workBuffer, 0, hashMessage, 32);
-        snprintf(strings.tmp.tmp,
-                 sizeof(strings.tmp.tmp),
-                 "%.*H",
-                 sizeof(hashMessage),
-                 hashMessage);
 
 #ifdef NO_CONSENT
         io_seproxyhal_touch_signMessage_ok(NULL);

src_features/signMessage/ui_flow_signMessage.c

@@ -14,7 +14,7 @@ UX_STEP_NOCB(
     ux_sign_flow_2_step,
     bnnn_paging,
     {
-      .title = "Message hash",
+      .title = "Message",
       .text = strings.tmp.tmp,
     });
 UX_STEP_CB(