From 6aa2f46b0815e63a4133784042aaa136e2482c24 Mon Sep 17 00:00:00 2001
From: Christian Ulrich <christian@ulrich.earth>
Date: Sun, 15 Nov 2020 17:18:45 +0100
Subject: [PATCH] introduce base32 peer IDs

---
 base32.nim  | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 quicp2p.nim | 18 ++++++++++--
 2 files changed, 99 insertions(+), 2 deletions(-)
 create mode 100644 base32.nim

diff --git a/base32.nim b/base32.nim
new file mode 100644
index 0000000..bfa2a69
--- /dev/null
+++ b/base32.nim
@@ -0,0 +1,83 @@
+#
+#          Nim's Unofficial Library
+#        (c) Copyright 2015 Huy Doan
+#
+#    See the file "LICENSE", included in this
+#    distribution, for details about the copyright.
+#
+
+## This module implements a base32 encoder and decoder.
+
+const
+  VERSION* = "0.1.2"
+
+  base32Chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567="
+
+proc encode*(s: openArray[char]; pad=true): string =
+  var i, j, idx, digit: int = 0
+  var current, next: int
+
+  var len = (s.len * 8 / 5).int
+  if len mod 8 != 0:
+     len += 8 - (len mod 8)
+
+  result = newString(len)
+
+  while i < s.len:
+    current = s[i].ord
+
+    if idx > 3:
+      if i + 1 < s.len:
+        next = s[i+1].ord
+      else:
+        next = 0
+
+      digit = current and (0xFF shr idx)
+      idx = (idx + 5) mod 8
+      digit = digit shl idx
+      digit = digit or (next shr (8 - idx))
+
+      i += 1
+    else:
+      digit = (current shr (8 - (idx + 5))) and 0x1F
+      idx = (idx + 5) mod 8
+      if idx == 0:
+        i += 1
+
+    result[j] = base32Chars[digit]
+    j += 1
+  if pad:
+    for i in j..<len:
+      result[i] = base32Chars[32]
+  else:
+    result.setLen j
+
+proc decode*(s: openArray[char]): string =
+  var ch, idx, bits, buf: int = 0
+  let len = (s.len * 5 / 8).int
+
+  result = newString(len)
+
+  for i in 0..s.len-1:
+    ch = s[i].ord
+
+    case ch
+    of 0x41..0x5A, 0x61..0x7A:
+      ch = (ch and 0x1F) - 1
+    of 0x32..0x37:
+      ch -= 0x32 - 26
+    of 0x3D:
+      continue
+    else:
+      raise newException(ValueError, "Non-base32 digit found: " & $ch)
+
+    buf = buf shl 5
+    buf = buf xor ch
+    bits += 5
+
+    if bits >= 8:
+      bits -= 8
+      result[idx] = char(buf shr bits and 0xFF)
+      idx += 1
+  if idx < len:
+    setLen(result, idx)
diff --git a/quicp2p.nim b/quicp2p.nim
index f215826..fae2e5a 100644
--- a/quicp2p.nim
+++ b/quicp2p.nim
@@ -2,6 +2,7 @@
 
 import asyncdispatch
 import asyncnet
+import base32
 import certificate
 import net
 import os
@@ -68,6 +69,18 @@ proc getRelativeTimeout(ctx: QuicP2PContext): int32 =
     let delta = nextTimeout - now
     result = min(delta, int32.high).int32
 
+proc getPeerId(ctx: QuicP2PContext): string =
+  assert(ctx.tlsCtx.certificates.count == 2)
+  let firstCertAddr = cast[ByteAddress](ctx.tlsCtx.certificates.list)
+  let secondCertIovec = cast[ptr ptls_iovec_t](firstCertAddr + sizeof(ptls_iovec_t))
+  var caCert = newString(secondCertIovec.len)
+  copyMem(caCert.cstring, secondCertIovec.base, secondCertIovec.len)
+  result = caCert.getPublicKey().encode(pad = false)
+
+proc getPeerId(conn: Connection): string =
+  assert(conn.certs.len() == 2)
+  result = conn.certs[1].getPublicKey().encode(pad = false)
+
 proc onStopSending(stream: ptr quicly_stream_t, err: cint) {.cdecl.} =
   echo "onStopSending"
   discard quicly_close(stream.conn, 0x30000, "")
@@ -84,7 +97,7 @@ proc onServerReceive(stream: ptr quicly_stream_t, offset: csize_t, src: pointer,
   var msg = newString(input.len)
   copyMem(addr msg[0], input.base, input.len)
   let conn = cast[Connection](quicly_get_data(stream.conn)[])
-  echo &"client {conn.certs[1].getPublicKey().toHex()} sends \"{msg}\""
+  echo &"client {conn.getPeerId()} sends \"{msg}\""
   if quicly_sendstate_is_open(addr stream.sendstate) != 0 and input.len > 0:
     discard quicly_streambuf_egress_write(stream, input.base, input.len)
     if quicly_recvstate_transfer_complete(addr stream.recvstate) != 0:
@@ -99,7 +112,7 @@ proc onClientReceive(stream: ptr quicly_stream_t, offset: csize_t,
   let msg = newString(input.len)
   copyMem(msg.cstring, input.base, input.len)
   let conn = cast[Connection](quicly_get_data(stream.conn)[])
-  echo &"server {conn.certs[1].getPublicKey().toHex()} sends \"{msg}\""
+  echo &"server {conn.getPeerId()} sends \"{msg}\""
   if quicly_recvstate_transfer_complete(addr stream.recvstate) != 0:
     discard quicly_close(stream.conn, 0, "")
   quicly_streambuf_ingress_shift(stream, input.len)
@@ -333,6 +346,7 @@ proc main() =
     usage()
     quit(1)
 
+  echo "My peer ID is ", ctx.getPeerId()
   while true:
     let nextTimeout = ctx.getRelativeTimeout()
     poll(nextTimeout)