From: Matt Corallo <git@bluematt.me>
Date: Mon, 26 Aug 2019 20:27:19 +0000 (-0400)
Subject: Support scanning by .onion hostname
X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=588be32d9817a67933417836c870d30d3aaf3448;p=dnsseed-rust

Support scanning by .onion hostname
---

diff --git a/src/reader.rs b/src/reader.rs
index 08dc5f0..0098ef4 100644
--- a/src/reader.rs
+++ b/src/reader.rs
@@ -1,7 +1,7 @@
 use std::sync::Arc;
 use std::sync::atomic::Ordering;
 use std::io::BufReader;
-use std::net::{IpAddr, SocketAddr};
+use std::net::{IpAddr, Ipv6Addr, SocketAddr};
 use std::time::Instant;
 
 use tokio::prelude::*;
@@ -15,6 +15,56 @@ use crate::{START_SHUTDOWN, scan_node};
 
 use regex::Regex;
 
+// base32 decoder and tests stolen (transliterated) from Bitcoin Core
+// Copyright (c) 2012-2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see
+// http://www.opensource.org/licenses/mit-license.php.
+fn decode_base32(inp: &[u8]) -> Option<Vec<u8>> {
+	let decode32_table: [i8; 256] = [
+		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, -1, -1, -1, -1,
+		-1, -1, -1, -1, -1,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
+		15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1,  0,  1,  2,
+		 3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,
+		23, 24, 25, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
+	];
+
+	let mut ret = Vec::with_capacity((inp.len() * 5) / 8);
+
+	let mut acc: u16 = 0;
+	let mut bits: u8 = 0;
+	for i in inp {
+		if *i == '=' as u8 { break; }
+		let codepoint = decode32_table[*i as usize];
+		if codepoint < 0 { return None; }
+		acc = ((acc << 5) | codepoint as u16) & ((1 << (8 + 5 - 1)) - 1);
+		bits += 5;
+		while bits >= 8 {
+			bits -= 8;
+			ret.push((acc >> bits) as u8);
+		}
+	}
+	Some(ret)
+}
+
+#[test]
+fn test_decode_base32() {
+	let tests_in = ["","f","fo","foo","foob","fooba","foobar"];
+	let tests_out = ["","my======","mzxq====","mzxw6===","mzxw6yq=","mzxw6ytb","mzxw6ytboi======"];
+	for (inp, out) in tests_in.iter().zip(tests_out.iter()) {
+		assert_eq!(&decode_base32(out.as_bytes()).unwrap()[..], inp.as_bytes());
+	}
+	// My seednode's onion addr:
+	assert_eq!(decode_base32("nkf5e6b7pl4jfd4a".as_bytes()).unwrap()[..],[0x6a, 0x8b, 0xd2, 0x78, 0x3f, 0x7a, 0xf8, 0x92, 0x8f, 0x80]);
+}
+
 pub fn read(store: &'static Store, printer: &'static Printer, bgp_client: Arc<BGPClient>) {
 	tokio::spawn(lines(BufReader::new(stdin())).for_each(move |line| {
 		macro_rules! err {
@@ -54,7 +104,23 @@ pub fn read(store: &'static Store, printer: &'static Printer, bgp_client: Arc<BG
 					Err(_) => err!(),
 				});
 			},
-			"a" => scan_node(Instant::now(), try_parse_next_chunk!(SocketAddr), true),
+			"a" => {
+				let host_port = get_next_chunk!();
+				let parsed = if host_port.len() > 23 && &host_port[16..23] == ".onion:" {
+					let port = match host_port[23..].parse::<u16>() { Ok(res) => res, Err(_) => err!(), };
+
+					let ipv6 = match decode_base32(host_port[0..16].as_bytes()) { Some(res) => res, None => err!(), };
+					if ipv6.len() != 10 { err!(); }
+					let mut octets = [0xFD,0x87,0xD8,0x7E,0xEB,0x43, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0];
+					octets[6..].copy_from_slice(&ipv6[0..10]);
+
+					SocketAddr::new(IpAddr::V6(Ipv6Addr::from(octets)), port)
+				} else {
+					match host_port.parse::<SocketAddr>() {
+						Ok(res) => res, Err(_) => err!(), }
+				};
+				scan_node(Instant::now(), parsed, true)
+			},
 			"b" => {
 				let ip = try_parse_next_chunk!(IpAddr);
 				printer.add_line(format!("ASN for {} is {}", ip, bgp_client.get_asn(ip)), false);