Now initializes a path in memory

src_features/signMessageEIP712/context.c

@@ -4,6 +4,7 @@
 #include "eip712.h"
 #include "mem.h"
 #include "sol_typenames.h"
+#include "path.h"
 
 uint8_t  *typenames_array;
 uint8_t  *structs_array;
@@ -21,9 +22,16 @@ bool    init_eip712_context(void)
     if (init_sol_typenames() == false)
         return false;
 
+    if (init_path() == false)
+    {
+        return false;
+    }
+
     // set types pointer
     if ((structs_array = mem_alloc(sizeof(uint8_t))) == NULL)
+    {
         return false;
+    }
 
     // create len(types)
     *structs_array = 0;

src_features/signMessageEIP712/encode_field.c

@@ -60,6 +60,10 @@ void    *encode_integer(const uint8_t *const value, uint16_t length)
 {
     uint8_t *padded_value;
 
+    if (length > 32) // sanity check
+    {
+        return NULL;
+    }
     // 0-pad the value to 32 bytes
     if ((padded_value = mem_alloc(EIP_712_ENCODED_FIELD_LENGTH)) != NULL)
     {
@@ -93,7 +97,7 @@ void    *encode_string(const char *const value, uint16_t length)
  */
 void    *encode_bool(const bool *const value, uint16_t length)
 {
-    if (length != 1)
+    if (length != 1) // sanity check
     {
         return NULL;
     }
@@ -109,7 +113,7 @@ void    *encode_bool(const bool *const value, uint16_t length)
  */
 void    *encode_address(const uint8_t *const value, uint16_t length)
 {
-    if (length != ADDRESS_LENGTH)
+    if (length != ADDRESS_LENGTH) // sanity check
     {
         return NULL;
     }

src_features/signMessageEIP712/entrypoint.c

@@ -258,6 +258,7 @@ bool    set_struct_name(const uint8_t *const data)
     return true;
 }
 
+// TODO: Split this function
 bool    set_struct_field(const uint8_t *const data)
 {
     uint8_t data_idx = OFFSET_DATA;

src_features/signMessageEIP712/field_hash.c

@@ -9,6 +9,8 @@ const uint8_t *field_hash(const void *const structs_array,
     (void)structs_array;
     (void)data;
     (void)data_length;
+    // get field by path
     encode_integer(data, data_length);
+    // path += 1
     return NULL;
 }

src_features/signMessageEIP712/path.c

@@ -0,0 +1,22 @@
+#include <stdint.h>
+#include <string.h>
+#include "path.h"
+#include "mem.h"
+#include "context.h"
+
+uint8_t  *path_indexes;
+
+/**
+ * Allocates the the path indexes in memory and sets them all to 0 with a count of 1.
+ */
+bool    init_path(void)
+{
+    // + 1 for the used index count
+    if ((path_indexes = mem_alloc(sizeof(uint8_t) * (MAX_PATH_DEPTH + 1))) != NULL)
+    {
+        // set all to 0
+        explicit_bzero(path_indexes + 1, sizeof(uint8_t) * MAX_PATH_DEPTH);
+        *path_indexes = 1; // init count at 1, so the default path will be 0
+    }
+    return path_indexes != NULL;
+}

src_features/signMessageEIP712/path.h

@@ -0,0 +1,12 @@
+#ifndef PATH_H_
+#define PATH_H_
+
+#include <stdbool.h>
+
+#define MAX_PATH_DEPTH  16
+
+extern uint8_t  *path_indexes;
+
+bool    init_path(void);
+
+#endif // PATH_H_