feat: recursive resolution + full DNSSEC validation

Numa becomes a true DNS resolver — resolves from root nameservers
with complete DNSSEC chain-of-trust verification.

Recursive resolution:
- Iterative RFC 1034 from configurable root hints (13 default)
- CNAME chasing (depth 8), referral following (depth 10)
- A+AAAA glue extraction, IPv6 nameserver support
- TLD priming: NS + DS + DNSKEY for 34 gTLDs + EU ccTLDs
- Config: mode = "recursive" in [upstream], root_hints, prime_tlds

DNSSEC (all 4 phases):
- EDNS0 OPT pseudo-record (DO bit, 1232 payload per DNS Flag Day 2020)
- DNSKEY, DS, RRSIG, NSEC, NSEC3 record types with wire read/write
- Signature verification via ring: RSA/SHA-256, ECDSA P-256, Ed25519
- Chain-of-trust: zone DNSKEY → parent DS → root KSK (key tag 20326)
- DNSKEY RRset self-signature verification (RRSIG(DNSKEY) by KSK)
- RRSIG expiration/inception time validation
- NSEC: NXDOMAIN gap proofs, NODATA type absence, wildcard denial
- NSEC3: SHA-1 iterated hashing, closest encloser proof, hash range
- Authority RRSIG verification for denial proofs
- Config: [dnssec] enabled/strict (default false, opt-in)
- AD bit on Secure, SERVFAIL on Bogus+strict
- DnssecStatus cached per entry, ValidationStats logging

Performance:
- TLD chain pre-warmed on startup (root DNSKEY + TLD DS/DNSKEY)
- Referral DS piggybacking from authority sections
- DNSKEY prefetch before validation loop
- Cold-cache validation: ~1 DNSKEY fetch (down from 5)
- Benchmarks: RSA 10.9µs, ECDSA 174ns, DS verify 257ns

Also:
- write_qname fix for root domain "." (was producing malformed queries)
- write_record_header() dedup, write_bytes() bulk writes
- DnsRecord::domain() + query_type() accessors
- UpstreamMode enum, DEFAULT_EDNS_PAYLOAD const
- Real glue TTL (was hardcoded 3600)
- DNSSEC restricted to recursive mode only

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
This commit is contained in:
Razvan Dimescu
2026-03-27 16:45:36 +02:00
parent cc8d3c7a83
commit 637b374d8b
23 changed files with 4325 additions and 98 deletions

128
tests/network-probe.sh Executable file
View File

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#!/usr/bin/env bash
# Network probe: tests which DNS transports are available on the current network.
# Run on a problematic network to diagnose what's blocked.
# Usage: ./tests/network-probe.sh
set -euo pipefail
GREEN="\033[32m"
RED="\033[31m"
DIM="\033[90m"
RESET="\033[0m"
PASSED=0
FAILED=0
probe() {
local name="$1"
local cmd="$2"
local expect="$3"
local result
result=$(eval "$cmd" 2>&1) || true
if echo "$result" | grep -q "$expect"; then
PASSED=$((PASSED + 1))
printf " ${GREEN}${RESET} %-45s ${DIM}%s${RESET}\n" "$name" "$(echo "$result" | head -1 | cut -c1-60)"
else
FAILED=$((FAILED + 1))
printf " ${RED}${RESET} %-45s ${DIM}blocked/timeout${RESET}\n" "$name"
fi
}
echo ""
echo "Network DNS Transport Probe"
echo "==========================="
echo "Network: $(networksetup -getairportnetwork en0 2>/dev/null | sed 's/Current Wi-Fi Network: //' || echo 'unknown')"
echo "Local IP: $(ipconfig getifaddr en0 2>/dev/null || echo 'unknown')"
echo "Gateway: $(route -n get default 2>/dev/null | grep gateway | awk '{print $2}' || echo 'unknown')"
echo ""
echo "=== UDP port 53 (recursive resolution) ==="
probe "Root server a (198.41.0.4)" \
"dig @198.41.0.4 . NS +short +time=5 +tries=1" \
"root-servers"
probe "Root server k (193.0.14.129)" \
"dig @193.0.14.129 . NS +short +time=5 +tries=1" \
"root-servers"
probe "Google DNS (8.8.8.8)" \
"dig @8.8.8.8 google.com A +short +time=5 +tries=1" \
"\."
probe "Cloudflare (1.1.1.1)" \
"dig @1.1.1.1 cloudflare.com A +short +time=5 +tries=1" \
"\."
probe ".com TLD (192.5.6.30)" \
"dig @192.5.6.30 google.com NS +short +time=5 +tries=1" \
"google"
echo ""
echo "=== TCP port 53 ==="
probe "Google DNS TCP (8.8.8.8)" \
"dig @8.8.8.8 google.com A +short +tcp +time=5 +tries=1" \
"\."
probe "Root server TCP (198.41.0.4)" \
"dig @198.41.0.4 . NS +short +tcp +time=5 +tries=1" \
"root-servers"
echo ""
echo "=== DoT port 853 (DNS-over-TLS) ==="
probe "Quad9 DoT (9.9.9.9:853)" \
"echo Q | openssl s_client -connect 9.9.9.9:853 -servername dns.quad9.net 2>&1 | grep 'verify return'" \
"verify return"
probe "Cloudflare DoT (1.1.1.1:853)" \
"echo Q | openssl s_client -connect 1.1.1.1:853 -servername cloudflare-dns.com 2>&1 | grep 'verify return'" \
"verify return"
echo ""
echo "=== DoH port 443 (DNS-over-HTTPS) ==="
probe "Quad9 DoH (dns.quad9.net)" \
"curl -s -m 5 -H 'accept: application/dns-json' 'https://dns.quad9.net:443/dns-query?name=google.com&type=A'" \
"Answer"
probe "Cloudflare DoH (1.1.1.1)" \
"curl -s -m 5 -H 'accept: application/dns-json' 'https://1.1.1.1/dns-query?name=google.com&type=A'" \
"Answer"
probe "Google DoH (dns.google)" \
"curl -s -m 5 'https://dns.google/resolve?name=google.com&type=A'" \
"Answer"
echo ""
echo "=== ISP DNS ==="
# Detect system DNS
SYS_DNS=$(scutil --dns 2>/dev/null | grep "nameserver\[0\]" | head -1 | awk '{print $3}' || echo "unknown")
if [ "$SYS_DNS" != "unknown" ] && [ "$SYS_DNS" != "127.0.0.1" ]; then
probe "ISP DNS ($SYS_DNS)" \
"dig @$SYS_DNS google.com A +short +time=5 +tries=1" \
"\."
else
printf " ${DIM} System DNS is $SYS_DNS (skipped)${RESET}\n"
fi
echo ""
echo "==========================="
TOTAL=$((PASSED + FAILED))
printf "Results: ${GREEN}%d passed${RESET}, ${RED}%d blocked${RESET} / %d total\n" "$PASSED" "$FAILED" "$TOTAL"
echo ""
echo "Recommendation:"
if [ "$FAILED" -eq 0 ]; then
echo " All transports available. Recursive mode will work."
elif dig @198.41.0.4 . NS +short +time=5 +tries=1 2>&1 | grep -q "root-servers"; then
echo " UDP:53 works. Recursive mode will work."
else
echo " UDP:53 blocked — recursive mode will NOT work on this network."
if curl -s -m 5 'https://dns.quad9.net:443/dns-query?name=test.com&type=A' 2>&1 | grep -q "Answer"; then
echo " DoH (port 443) works — use mode = \"forward\" with DoH upstream."
elif echo Q | openssl s_client -connect 9.9.9.9:853 2>&1 | grep -q "verify return"; then
echo " DoT (port 853) works — DoT upstream would work (not yet implemented)."
else
echo " Only ISP DNS available. Use mode = \"forward\" with ISP auto-detect."
fi
fi