From 93ec3344cbca630a9e71d565807d095d8f9849d7 Mon Sep 17 00:00:00 2001
From: Boro Sitnikovski <buritomath@gmail.com>
Date: Fri, 13 Jul 2018 01:00:29 +0300
Subject: [PATCH] Store all data as strings for easier
 serialization/deserialization

---
 main-helper.rkt        |  5 +++--
 main.rkt               |  2 +-
 src/block.rkt          | 14 ++++++++------
 src/transaction-io.rkt |  6 +++---
 src/transaction.rkt    |  6 +++---
 src/utils.rkt          |  1 -
 6 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/main-helper.rkt b/main-helper.rkt
index 7d39f12..7d78bc7 100644
--- a/main-helper.rkt
+++ b/main-helper.rkt
@@ -1,6 +1,7 @@
 #lang racket
 (require "./src/blockchain.rkt")
 (require "./src/utils.rkt")
+
 (require (only-in sha bytes->hex-string))
 
 (define (format-transaction t)
@@ -11,8 +12,8 @@
 
 (define (print-block bl)
   (printf "Block information\n=================\nHash:\t~a\nHash_p:\t~a\nStamp:\t~a\nNonce:\t~a\nData:\t~a\n"
-          (bytes->hex-string (block-hash bl))
-          (bytes->hex-string (block-previous-hash bl))
+          (block-hash bl)
+          (block-previous-hash bl)
           (block-timestamp bl)
           (block-nonce bl)
           (format-transaction (block-transaction bl))))
diff --git a/main.rkt b/main.rkt
index 92e943e..a7674b9 100644
--- a/main.rkt
+++ b/main.rkt
@@ -22,7 +22,7 @@
 
 ; Blockchain initiation
 (printf "Mining genesis block...\n")
-(define blockchain (init-blockchain genesis-t (string->bytes/utf-8 "seedgenesis") utxo))
+(define blockchain (init-blockchain genesis-t "1337cafe" utxo))
 (print-wallets blockchain wallet-a wallet-b)
 
 ; Make a second transaction
diff --git a/src/block.rkt b/src/block.rkt
index 1891c1d..2270f03 100644
--- a/src/block.rkt
+++ b/src/block.rkt
@@ -1,19 +1,21 @@
 #lang racket
+(require "utils.rkt")
 (require (only-in sha sha256))
+(require (only-in sha bytes->hex-string))
 (require racket/serialize)
 
 (define difficulty 2)
-(define target (make-bytes difficulty 32))
+(define target (bytes->hex-string (make-bytes difficulty 32)))
 
 (struct block (hash previous-hash transaction timestamp nonce) #:prefab)
 
 ; Procedure for calculating block hash
 (define (calculate-block-hash previous-hash timestamp transaction nonce)
-  (sha256 (bytes-append
-           previous-hash
+  (bytes->hex-string (sha256 (bytes-append
+           (string->bytes/utf-8 previous-hash)
            (string->bytes/utf-8 (number->string timestamp))
            (string->bytes/utf-8 (~a (serialize transaction)))
-           (string->bytes/utf-8 (number->string nonce)))))
+           (string->bytes/utf-8 (number->string nonce))))))
 
 ; A block is valid if...
 (define (valid-block? bl)
@@ -27,8 +29,8 @@
 ; A block is mined if
 (define (mined-block? hash)
   ; the hash matches the target, given the difficulty
-  (equal? (subbytes hash 1 difficulty)
-          (subbytes target 1 difficulty)))
+  (equal? (subbytes (hex-string->bytes hash) 1 difficulty)
+          (subbytes (hex-string->bytes target) 1 difficulty)))
 
 ; Hashcash implementation
 (define (make-and-mine-block target previous-hash timestamp transaction nonce)
diff --git a/src/transaction-io.rkt b/src/transaction-io.rkt
index 0cba366..e7645ef 100644
--- a/src/transaction-io.rkt
+++ b/src/transaction-io.rkt
@@ -1,16 +1,16 @@
 #lang racket
-(require "utils.rkt")
 (require (only-in sha sha256))
+(require (only-in sha bytes->hex-string))
 (require racket/serialize)
 
 (struct transaction-io (hash value owner timestamp) #:prefab)
 
 ; Procedure for calculating the hash of a transaction-io object
 (define (calculate-transaction-io-hash value owner timestamp)
-  (sha256 (bytes-append
+  (bytes->hex-string (sha256 (bytes-append
            (string->bytes/utf-8 (number->string value))
            (string->bytes/utf-8 (~a (serialize owner)))
-           (string->bytes/utf-8 (number->string timestamp)))))
+           (string->bytes/utf-8 (number->string timestamp))))))
 
 ; Make a transaction-io object with calculated hash
 (define (make-transaction-io value owner)
diff --git a/src/transaction.rkt b/src/transaction.rkt
index 9530e4d..992e7a8 100644
--- a/src/transaction.rkt
+++ b/src/transaction.rkt
@@ -15,12 +15,12 @@
 (define (sign-transaction from to value)
   (let ([privkey (wallet-private-key from)]
         [pubkey (wallet-public-key from)])
-    (digest/sign (datum->pk-key (hex-string->bytes privkey) 'PrivateKeyInfo)
+    (bytes->hex-string (digest/sign (datum->pk-key (hex-string->bytes privkey) 'PrivateKeyInfo)
                  'sha1
                  (bytes-append
                   (string->bytes/utf-8 (~a (serialize from)))
                   (string->bytes/utf-8 (~a (serialize to)))
-                  (string->bytes/utf-8 (number->string value))))))
+                  (string->bytes/utf-8 (number->string value)))))))
 
 ; Make an empty, unprocessed and unsigned transaction
 (define (make-transaction from to value inputs)
@@ -64,7 +64,7 @@
                     (string->bytes/utf-8 (~a (serialize (transaction-from t))))
                     (string->bytes/utf-8 (~a (serialize (transaction-to t))))
                     (string->bytes/utf-8 (number->string (transaction-value t))))
-                   (transaction-signature t))))
+                   (hex-string->bytes (transaction-signature t)))))
 
 ; A transaction is valid if...
 (define (valid-transaction? t)
diff --git a/src/utils.rkt b/src/utils.rkt
index ead7b5c..74709cb 100644
--- a/src/utils.rkt
+++ b/src/utils.rkt
@@ -1,5 +1,4 @@
 #lang racket
-(require "block.rkt")
 (require racket/serialize)
 
 (define ASCII-ZERO (char->integer #\0))