Minor tidyups (#232)

* Don't add hash_def when not required

Exit hash_andor_sign_block early if neither hash_value not signature is needed

* Add validation that the partition name is < 128 characters long, as the size is only 7 bits

bintool/bintool.cpp

diff --git a/bintool/bintool.cpp b/bintool/bintool.cpp
index 5df18d2..e75c0b0 100644
--- a/bintool/bintool.cpp
+++ b/bintool/bintool.cpp
@@ -591,6 +591,11 @@
 
 #if HAS_MBEDTLS
 void hash_andor_sign_block(block *new_block, const public_t public_key, const private_t private_key, bool hash_value, bool sign, std::vector<uint8_t> to_hash) {
+    if (!(hash_value || sign)) {
+        // Don't need to add anything if not actually hashing or signing
+        return;
+    }
+
     std::shared_ptr<hash_def_item> hash_def = std::make_shared<hash_def_item>(PICOBIN_HASH_SHA256);
     new_block->items.push_back(hash_def);
 

bintool/metadata.h

diff --git a/bintool/metadata.h b/bintool/metadata.h
index f06fcbe..a01e048 100644
--- a/bintool/metadata.h
+++ b/bintool/metadata.h
@@ -208,6 +208,7 @@
             }
             if (name.size() > 0) {
                 char size = name.size();
+                assert(size & 0x7f == size);
                 std::vector<char> name_vec = {size};
                 for (char c : name) {
                     name_vec.push_back(c);

json/schemas/partition-table-schema.json

diff --git a/json/schemas/partition-table-schema.json b/json/schemas/partition-table-schema.json
index 92eadcd..2bfa2bf 100644
--- a/json/schemas/partition-table-schema.json
+++ b/json/schemas/partition-table-schema.json
@@ -52,7 +52,8 @@
                 "properties": {
                     "name": {
                         "description": "Partition Name",
-                        "type": "string"
+                        "type": "string",
+                        "maxLength": 127
                     },
                     "id": {
                         "description": "Partition ID",

main.cpp

diff --git a/main.cpp b/main.cpp
index 2819a41..7d5df3a 100644
--- a/main.cpp
+++ b/main.cpp
@@ -6607,7 +6607,13 @@
             }
             new_p.flags |= (link_value << PICOBIN_PARTITION_FLAGS_LINK_VALUE_LSB) & PICOBIN_PARTITION_FLAGS_LINK_VALUE_BITS;
         }
-        if (p.contains("name")) { new_p.name = p["name"]; new_p.flags |= PICOBIN_PARTITION_FLAGS_HAS_NAME_BITS; }
+        if (p.contains("name")) {
+            new_p.name = p["name"];
+            new_p.flags |= PICOBIN_PARTITION_FLAGS_HAS_NAME_BITS;
+            if (new_p.name.size() > 127) {
+                fail(ERROR_INCOMPATIBLE, "Partition name \"%s\" is %d characters long - max length is 127 characters\n", new_p.name.c_str(), new_p.name.size());
+            }
+        }
         if (p.contains("id")) {
             if (get_json_int(p["id"], new_p.id)) {new_p.flags |= PICOBIN_PARTITION_FLAGS_HAS_ID_BITS;}
             else {string p_id = p["id"]; fail(ERROR_INCOMPATIBLE, "Partition ID \"%s\" is not a valid 64bit integer\n", p_id.c_str());}