dnssec: use RSASHA256 keys for .email domains

management/dns_update.py

@@ -479,8 +479,18 @@ zone:
 
 ########################################################################
 
+def dnssec_choose_algo(domain, env):
+	if domain.endswith(".email"):
+		# At least at GoDaddy, this is the only algorithm supported.
+		return "RSASHA256"
+
+	# For any domain we were able to sign before, don't change the algorithm
+	# on existing users. We'll probably want to migrate to SHA256 later.
+	return "RSASHA1-NSEC3-SHA1"
+
 def sign_zone(domain, zonefile, env):
-	dnssec_keys = load_env_vars_from_file(os.path.join(env['STORAGE_ROOT'], 'dns/dnssec/keys.conf'))
+	algo = dnssec_choose_algo(domain, env)
+	dnssec_keys = load_env_vars_from_file(os.path.join(env['STORAGE_ROOT'], 'dns/dnssec/%s.conf' % algo))
 
 	# In order to use the same keys for all domains, we have to generate
 	# a new .key file with a DNSSEC record for the specific domain. We

management/status_checks.py

@@ -210,14 +210,15 @@ def check_dnssec(domain, env, dns_zonefiles, is_checking_primary=False):
 
 	# Some registrars may want the public key so they can compute the digest. The DS
 	# record that we suggest using is for the KSK (and that's how the DS records were generated).
-	dnssec_keys = load_env_vars_from_file(os.path.join(env['STORAGE_ROOT'], 'dns/dnssec/keys.conf'))
+	alg_name_map = { '7': 'RSASHA1-NSEC3-SHA1', '8': 'RSASHA256' }
+	dnssec_keys = load_env_vars_from_file(os.path.join(env['STORAGE_ROOT'], 'dns/dnssec/%s.conf' % alg_name_map[ds_alg]))
 	dnsssec_pubkey = open(os.path.join(env['STORAGE_ROOT'], 'dns/dnssec/' + dnssec_keys['KSK'] + '.key')).read().split("\t")[3].split(" ")[3]
 
 	# Query public DNS for the DS record at the registrar.
 	ds = query_dns(domain, "DS", nxdomain=None)
 	ds_looks_valid = ds and len(ds.split(" ")) == 4
 	if ds_looks_valid: ds = ds.split(" ")
-	if ds_looks_valid and ds[0] == ds_keytag and ds[1] == '7' and ds[3] == digests.get(ds[2]):
+	if ds_looks_valid and ds[0] == ds_keytag and ds[1] == ds_alg and ds[3] == digests.get(ds[2]):
 		if is_checking_primary: return
 		env['out'].print_ok("DNSSEC 'DS' record is set correctly at registrar.")
 	else:
@@ -236,7 +237,9 @@ def check_dnssec(domain, env, dns_zonefiles, is_checking_primary=False):
 		env['out'].print_line("")
 		env['out'].print_line("Key Tag: " + ds_keytag + ("" if not ds_looks_valid or ds[0] == ds_keytag else " (Got '%s')" % ds[0]))
 		env['out'].print_line("Key Flags: KSK")
-		env['out'].print_line("Algorithm: 7 / RSASHA1-NSEC3-SHA1" + ("" if not ds_looks_valid or ds[1] == '7' else " (Got '%s')" % ds[1]))
+		env['out'].print_line(
+			  ("Algorithm: %s / %s" % (ds_alg, alg_name_map[ds_alg]))
+			+ ("" if not ds_looks_valid or ds[1] == ds_alg else " (Got '%s')" % ds[1]))
 			# see http://www.iana.org/assignments/dns-sec-alg-numbers/dns-sec-alg-numbers.xhtml
 		env['out'].print_line("Digest Type: 2 / SHA-256")
 			# http://www.ietf.org/assignments/ds-rr-types/ds-rr-types.xml

setup/dns.sh

@@ -36,25 +36,39 @@ sudo mkdir -p /var/run/nsd
 # Create DNSSEC signing keys.
 
 mkdir -p "$STORAGE_ROOT/dns/dnssec";
-if [ ! -f "$STORAGE_ROOT/dns/dnssec/keys.conf" ]; then
+
-	echo "Generating DNSSEC signing keys. This may take a few minutes..."
+# TLDs don't all support the same algorithms, so we'll generate keys using a few
+# different algorithms.
+#
+# Supports RSASHA1-NSEC3-SHA1 (didn't test with RSASHA256):
+#   .info and .me.
+#
+# Requires RSASHA256
+#   .email
+FIRST=1
+for algo in RSASHA1-NSEC3-SHA1 RSASHA256; do
+if [ ! -f "$STORAGE_ROOT/dns/dnssec/$algo.conf" ]; then
+	if [ $FIRST == 1 ]; then
+		echo "Generating DNSSEC signing keys. This may take a few minutes..."
+		FIRST=0
+	fi
 
 	# Create the Key-Signing Key (KSK) (-k) which is the so-called
 	# Secure Entry Point. Use a NSEC3-compatible algorithm (best
 	# practice), and a nice and long keylength. The domain name we
 	# provide ("_domain_") doesn't matter -- we'll use the same
 	# keys for all our domains.
-	KSK=$(umask 077; cd $STORAGE_ROOT/dns/dnssec; ldns-keygen -a RSASHA1-NSEC3-SHA1 -b 2048 -k _domain_);
+	KSK=$(umask 077; cd $STORAGE_ROOT/dns/dnssec; ldns-keygen -a $algo -b 2048 -k _domain_);
 
 	# Now create a Zone-Signing Key (ZSK) which is expected to be
 	# rotated more often than a KSK, although we have no plans to
 	# rotate it (and doing so would be difficult to do without
 	# disturbing DNS availability.) Omit '-k' and use a shorter key.
-	ZSK=$(umask 077; cd $STORAGE_ROOT/dns/dnssec; ldns-keygen -a RSASHA1-NSEC3-SHA1 -b 1024 _domain_);
+	ZSK=$(umask 077; cd $STORAGE_ROOT/dns/dnssec; ldns-keygen -a $algo -b 1024 _domain_);
 
 	# These generate two sets of files like:
 	#
-	# * `K_domain_.+007+08882.ds`: DS record to provide to domain name registrar
+	# * `K_domain_.+007+08882.ds`: DS record normally provided to domain name registrar (but it's actually invalid with "_domain_")
 	# * `K_domain_.+007+08882.key`: public key (goes into DS record & upstream DNS provider like your registrar)
 	# * `K_domain_.+007+08882.private`: private key (secret!)
 
@@ -62,11 +76,12 @@ if [ ! -f "$STORAGE_ROOT/dns/dnssec/keys.conf" ]; then
 	# options. So we'll store the names of the files we just generated.
 	# We might have multiple keys down the road. This will identify
 	# what keys are the current keys.
-	cat > $STORAGE_ROOT/dns/dnssec/keys.conf << EOF;
+	cat > $STORAGE_ROOT/dns/dnssec/$algo.conf << EOF;
 KSK=$KSK
 ZSK=$ZSK
 EOF
 fi
+done
 
 # Force the dns_update script to be run every day to re-sign zones for DNSSEC.
 cat > /etc/cron.daily/mailinabox-dnssec << EOF;

setup/migrate.py

@@ -60,6 +60,13 @@ def migration_5(env):
 	# The secret key for encrypting backups was world readable. Fix here.
 	os.chmod(os.path.join(env["STORAGE_ROOT"], 'backup/secret_key.txt'), 0o600)
 
+def migration_6(env):
+	# We now will generate multiple DNSSEC keys for different algorithms, since TLDs may
+	# not support them all. .email only supports RSA/SHA-256. Rename the keys.conf file
+	# to be algorithm-specific.
+	basepath = os.path.join(env["STORAGE_ROOT"], 'dns/dnssec')
+	shutil.move(os.path.join(basepath, 'keys.conf'), os.path.join(basepath, 'RSASHA1-NSEC3-SHA1.conf'))
+
 def get_current_migration():
 	ver = 0
 	while True: