[wip] ironing out bugs in tx signing procedure

this time learned
- need to have tag and version for the return data
- i think i need to sign the hash of the transaction rather than the transaction

libs/vdk_rlp/jex.eterms

@@ -2,4 +2,4 @@
 {realm, local}.
 {name, vdk_rlp}.
 {version, "0.1.0"}.
-{deps, []}.
+{deps, ["local-vdk_binary-0.1.0"]}.

libs/vdk_rlp/src/vdk_rlp.ts

@@ -19,9 +19,13 @@ export {
     decoded_data,
     decode_result,
     decode,
-    encode
+    encode,
+    encode_uint,
+    encode_biguint
 }
 
+import * as vdk_binary from './jex_include/local-vdk_binary-0.1.0/dist/vdk_binary.js';
+
 
 //=============================================================================
 //=============================================================================
@@ -519,3 +523,29 @@ is_list
 {
     return (x instanceof Array);
 }
+
+
+
+/**
+ * Encode an non-negative integer into RLP
+ */
+function
+encode_uint
+    (n: number)
+    : Uint8Array
+{
+    return encode_biguint(BigInt(n));
+}
+
+
+/**
+ * Encode an unsigned BigInt into RLP
+ */
+function
+encode_biguint
+    (n: bigint)
+    : Uint8Array
+{
+    let bytes : Uint8Array = vdk_binary.bigint_to_bytes(n);
+    return encode(bytes);
+}