Fix multiple vulnerabilities

src/main.c

@@ -480,6 +480,36 @@ void handleGetWalletId(volatile unsigned int *tx) {
 
 #endif  // HAVE_WALLET_ID_SDK
 
+uint8_t *parseBip32(uint8_t *dataBuffer, uint16_t *dataLength, bip32_path_t *bip32) {
+    if (*dataLength < 1) {
+        PRINTF("Invalid data\n");
+        return NULL;
+    }
+
+    bip32->length = *dataBuffer;
+
+    if (bip32->length < 0x1 || bip32->length > MAX_BIP32_PATH) {
+        PRINTF("Invalid bip32\n");
+        return NULL;
+    }
+
+    dataBuffer++;
+    (*dataLength)--;
+
+    if (*dataLength < sizeof(uint32_t) * (bip32->length)) {
+        PRINTF("Invalid data\n");
+        return NULL;
+    }
+
+    for (uint8_t i = 0; i < bip32->length; i++) {
+        bip32->path[i] = U4BE(dataBuffer, 0);
+        dataBuffer += sizeof(uint32_t);
+        *dataLength -= sizeof(uint32_t);
+    }
+
+    return dataBuffer;
+}
+
 void handleApdu(unsigned int *flags, unsigned int *tx) {
     unsigned short sw = 0;
 

src/shared_context.h

@@ -18,6 +18,11 @@
 
 #define N_storage (*(volatile internalStorage_t *) PIC(&N_storage_real))
 
+typedef struct bip32_path_t {
+    uint8_t length;
+    uint32_t path[MAX_BIP32_PATH];
+} bip32_path_t;
+
 typedef struct internalStorage_t {
     unsigned char dataAllowed;
     unsigned char contractDetails;
@@ -82,8 +87,7 @@ typedef union extraInfo_t {
 } extraInfo_t;
 
 typedef struct transactionContext_t {
-    uint8_t pathLength;
-    uint32_t bip32Path[MAX_BIP32_PATH];
+    bip32_path_t bip32;
     uint8_t hash[INT256_LENGTH];
     union extraInfo_t extraInfo[MAX_ITEMS];
     uint8_t tokenSet[MAX_ITEMS];
@@ -91,15 +95,13 @@ typedef struct transactionContext_t {
 } transactionContext_t;
 
 typedef struct messageSigningContext_t {
-    uint8_t pathLength;
-    uint32_t bip32Path[MAX_BIP32_PATH];
+    bip32_path_t bip32;
     uint8_t hash[INT256_LENGTH];
     uint32_t remainingLength;
 } messageSigningContext_t;
 
 typedef struct messageSigningContext712_t {
-    uint8_t pathLength;
-    uint32_t bip32Path[MAX_BIP32_PATH];
+    bip32_path_t bip32;
     uint8_t domainHash[32];
     uint8_t messageHash[32];
 } messageSigningContext712_t;
@@ -217,5 +219,6 @@ extern uint32_t eth2WithdrawalIndex;
 #endif
 
 void reset_app_context(void);
+uint8_t *parseBip32(uint8_t *, uint16_t *, bip32_path_t *);
 
 #endif  // _SHARED_CONTEXT_H_