errata 2019.04.19

Author: jimmysong

ch02.asciidoc

@@ -398,7 +398,7 @@ From earlier, we know that:
 
 ++++
 <ul class="simplelist">
-<li><em>x</em><sup>3</sup> – <em>s</em><sup>2</sup><em>x</em><sup>2</sup> + (<em>a</em> + 2<em>s</em><sup>2</sup><em>x</em><sub>1</sub> – 2<em>sy</em>~1~)<em>x</em> + <em>b</em> – <em>s</em><sup>2</sup><em>x</em><sub>1</sub><sup>2</sup> + 2<em>sx</em>~1~<em>y</em><sub>1</sub> – <em>y</em><sub>1</sub><sup>2</sup> = 0</li>
+<li><em>x</em><sup>3</sup> – <em>s</em><sup>2</sup><em>x</em><sup>2</sup> + (<em>a</em> + 2<em>s</em><sup>2</sup><em>x</em><sub>1</sub> – 2<em>sy</em>~1~)<em>x</em> + <em>b</em> – <em>s</em><sup>2</sup><em>x</em><sub>1</sub><sup>2</sup> + 2<em>sx</em><sub>1</sub><em>y</em><sub>1</sub> – <em>y</em><sub>1</sub><sup>2</sup> = 0</li>
 </ul>
 ++++
 

ch10.asciidoc

@@ -74,7 +74,7 @@ The timestamp field is 8 bytes (as opposed to 4 bytes in the block header) and i
 
 IP addresses can be IPv6, IPv4, or OnionCat (a mapping of TOR's `.onion` addresses to IPv6).
 If IPv4, the first 12 bytes are `00000000000000000000ffff` and the last 4 bytes are the IP.
-The port is 2 bytes in little-endian. The default on mainnet is 8333, which maps to `8d20` in little-endian hex.
+The port is 2 bytes in big-endian. The default on mainnet is 8333, which maps to `208d` in big-endian hex.
 
 A nonce is a number used by a node to detect a connection to itself.
 The user agent identifies the software being run.

code-ch02/Chapter2.ipynb

@@ -168,7 +168,7 @@
    "source": [
     "### Exercise 6\n",
     "\n",
-    "For the curve \\\\(y^{2}\\\\)=\\\\(x^{3}\\\\)+5x+7, what is (2,5) + (-1,-1)?"
+    "For the curve \\\\(y^{2}\\\\)=\\\\(x^{3}\\\\)+5x+7, what is (-1,-1) + (-1,-1)?"
    ]
   },
   {
@@ -183,8 +183,8 @@
     "\n",
     "a = 5\n",
     "b = 7\n",
-    "x1, y1 = -1, 1\n",
-    "# (-1,1) + (-1,1)"
+    "x1, y1 = -1, -1\n",
+    "# (-1,-1) + (-1,-1)"
    ]
   },
   {

code-ch02/answers.py

@@ -45,12 +45,12 @@
 For the curve __y__^2^ = __x__^3^ + 5__x__ + 7, what is (–1,–1) + (–1,–1)?
 # end::exercise6[]
 # tag::answer6[]
->>> a, x1, y1 = 5, -1, 1
+>>> a, x1, y1 = 5, -1, -1
 >>> s = (3 * x1**2 + a) / (2 * y1)
 >>> x3 = s**2 - 2*x1
 >>> y3 = s*(x1-x3)-y1
 >>> print(x3,y3)
-18.0 -77.0
+18.0 77.0
 
 # end::answer6[]
 '''

code-ch02/jupyter.txt

@@ -32,7 +32,7 @@ from ecc import Point
 
 a = 5
 b = 7
-x1, y1 = -1, 1
-# (-1,1) + (-1,1)
+x1, y1 = -1, -1
+# (-1,-1) + (-1,-1)
 ---
 exercise7:ecc:PointTest:test_add2

code-ch10/answers.py

@@ -11,7 +11,7 @@
 # tag::answer2[]
 >>> from network import NetworkEnvelope
 >>> from io import BytesIO
->>> message_hex = `f9beb4d976657261636b000000000000000000005df6e0e2`
+>>> message_hex = 'f9beb4d976657261636b000000000000000000005df6e0e2'
 >>> stream = BytesIO(bytes.fromhex(message_hex))
 >>> envelope = NetworkEnvelope.parse(stream)
 >>> print(envelope.command)
@@ -118,10 +118,10 @@ def serialize(self):
     result += int_to_little_endian(self.timestamp, 8)
     result += int_to_little_endian(self.receiver_services, 8)
     result += b'\x00' * 10 + b'\xff\xff' + self.receiver_ip
-    result += int_to_little_endian(self.receiver_port, 2)
+    result += self.receiver_port.to_bytes(2, 'big')
     result += int_to_little_endian(self.sender_services, 8)
     result += b'\x00' * 10 + b'\xff\xff' + self.sender_ip
-    result += int_to_little_endian(self.sender_port, 2)
+    result += self.sender_port.to_bytes(2, 'big')
     result += self.nonce
     result += encode_varint(len(self.user_agent))
     result += self.user_agent

code-ch10/network.py

@@ -138,10 +138,10 @@ def serialize(self):
         # timestamp is 8 bytes little endian
         # receiver services is 8 bytes little endian
         # IPV4 is 10 00 bytes and 2 ff bytes then receiver ip
-        # receiver port is 2 bytes, little endian should be 0
+        # receiver port is 2 bytes, big endian
         # sender services is 8 bytes little endian
         # IPV4 is 10 00 bytes and 2 ff bytes then sender ip
-        # sender port is 2 bytes, little endian should be 0
+        # sender port is 2 bytes, big endian
         # nonce should be 8 bytes
         # useragent is a variable string, so varint first
         # latest block is 4 bytes little endian
@@ -153,7 +153,7 @@ class VersionMessageTest(TestCase):
 
     def test_serialize(self):
         v = VersionMessage(timestamp=0, nonce=b'\x00' * 8)
-        self.assertEqual(v.serialize().hex(), '7f11010000000000000000000000000000000000000000000000000000000000000000000000ffff000000008d20000000000000000000000000000000000000ffff000000008d200000000000000000182f70726f6772616d6d696e67626974636f696e3a302e312f0000000000')
+        self.assertEqual(v.serialize().hex(), '7f11010000000000000000000000000000000000000000000000000000000000000000000000ffff00000000208d000000000000000000000000000000000000ffff00000000208d0000000000000000182f70726f6772616d6d696e67626974636f696e3a302e312f0000000000')
 
 
 # tag::source3[]

code-ch11/network.py

@@ -152,14 +152,14 @@ def serialize(self):
         result += int_to_little_endian(self.receiver_services, 8)
         # IPV4 is 10 00 bytes and 2 ff bytes then receiver ip
         result += b'\x00' * 10 + b'\xff\xff' + self.receiver_ip
-        # receiver port is 2 bytes, little endian should be 0
-        result += int_to_little_endian(self.receiver_port, 2)
+        # receiver port is 2 bytes, big endian
+        result += self.receiver_port.to_bytes(2, 'big')
         # sender services is 8 bytes little endian
         result += int_to_little_endian(self.sender_services, 8)
         # IPV4 is 10 00 bytes and 2 ff bytes then sender ip
         result += b'\x00' * 10 + b'\xff\xff' + self.sender_ip
-        # sender port is 2 bytes, little endian should be 0
-        result += int_to_little_endian(self.sender_port, 2)
+        # sender port is 2 bytes, big endian
+        result += self.sender_port.to_bytes(2, 'big')
         # nonce should be 8 bytes
         result += self.nonce
         # useragent is a variable string, so varint first
@@ -179,7 +179,7 @@ class VersionMessageTest(TestCase):
 
     def test_serialize(self):
         v = VersionMessage(timestamp=0, nonce=b'\x00' * 8)
-        self.assertEqual(v.serialize().hex(), '7f11010000000000000000000000000000000000000000000000000000000000000000000000ffff000000008d20000000000000000000000000000000000000ffff000000008d200000000000000000182f70726f6772616d6d696e67626974636f696e3a302e312f0000000000')
+        self.assertEqual(v.serialize().hex(), '7f11010000000000000000000000000000000000000000000000000000000000000000000000ffff00000000208d000000000000000000000000000000000000ffff00000000208d0000000000000000182f70726f6772616d6d696e67626974636f696e3a302e312f0000000000')
 
 
 class VerAckMessage:

code-ch12/network.py

@@ -156,14 +156,14 @@ def serialize(self):
         result += int_to_little_endian(self.receiver_services, 8)
         # IPV4 is 10 00 bytes and 2 ff bytes then receiver ip
         result += b'\x00' * 10 + b'\xff\xff' + self.receiver_ip
-        # receiver port is 2 bytes, little endian should be 0
-        result += int_to_little_endian(self.receiver_port, 2)
+        # receiver port is 2 bytes, big endian
+        result += self.receiver_port.to_bytes(2, 'big')
         # sender services is 8 bytes little endian
         result += int_to_little_endian(self.sender_services, 8)
         # IPV4 is 10 00 bytes and 2 ff bytes then sender ip
         result += b'\x00' * 10 + b'\xff\xff' + self.sender_ip
-        # sender port is 2 bytes, little endian should be 0
-        result += int_to_little_endian(self.sender_port, 2)
+        # sender port is 2 bytes, big endian
+        result += self.sender_port.to_bytes(2, 'big')
         # nonce should be 8 bytes
         result += self.nonce
         # useragent is a variable string, so varint first
@@ -183,7 +183,7 @@ class VersionMessageTest(TestCase):
 
     def test_serialize(self):
         v = VersionMessage(timestamp=0, nonce=b'\x00' * 8)
-        self.assertEqual(v.serialize().hex(), '7f11010000000000000000000000000000000000000000000000000000000000000000000000ffff000000008d20000000000000000000000000000000000000ffff000000008d200000000000000000182f70726f6772616d6d696e67626974636f696e3a302e312f0000000000')
+        self.assertEqual(v.serialize().hex(), '7f11010000000000000000000000000000000000000000000000000000000000000000000000ffff00000000208d000000000000000000000000000000000000ffff00000000208d0000000000000000182f70726f6772616d6d696e67626974636f696e3a302e312f0000000000')
 
 
 class VerAckMessage:

code-ch13/network.py

@@ -156,14 +156,14 @@ def serialize(self):
         result += int_to_little_endian(self.receiver_services, 8)
         # IPV4 is 10 00 bytes and 2 ff bytes then receiver ip
         result += b'\x00' * 10 + b'\xff\xff' + self.receiver_ip
-        # receiver port is 2 bytes, little endian should be 0
-        result += int_to_little_endian(self.receiver_port, 2)
+        # receiver port is 2 bytes, big endian
+        result += self.receiver_port.to_bytes(2, 'big')
         # sender services is 8 bytes little endian
         result += int_to_little_endian(self.sender_services, 8)
         # IPV4 is 10 00 bytes and 2 ff bytes then sender ip
         result += b'\x00' * 10 + b'\xff\xff' + self.sender_ip
-        # sender port is 2 bytes, little endian should be 0
-        result += int_to_little_endian(self.sender_port, 2)
+        # sender port is 2 bytes, big endian
+        result += self.sender_port.to_bytes(2, 'big')
         # nonce should be 8 bytes
         result += self.nonce
         # useragent is a variable string, so varint first
@@ -183,7 +183,7 @@ class VersionMessageTest(TestCase):
 
     def test_serialize(self):
         v = VersionMessage(timestamp=0, nonce=b'\x00' * 8)
-        self.assertEqual(v.serialize().hex(), '7f11010000000000000000000000000000000000000000000000000000000000000000000000ffff000000008d20000000000000000000000000000000000000ffff000000008d200000000000000000182f70726f6772616d6d696e67626974636f696e3a302e312f0000000000')
+        self.assertEqual(v.serialize().hex(), '7f11010000000000000000000000000000000000000000000000000000000000000000000000ffff00000000208d000000000000000000000000000000000000ffff00000000208d0000000000000000182f70726f6772616d6d696e67626974636f696e3a302e312f0000000000')
 
 
 class VerAckMessage:

preface.asciidoc

@@ -101,7 +101,7 @@ $ cd programmingbitcoin
 +
 [source,bash]
 ----
-$ pip install virtualenv
+$ pip install virtualenv --user
 ----
 
 . Install the requirements: