I ran the same test again, without changing anything, and it come back without error. not sure what that means, but just in case its of interest.
On 4/9/2015 12:09 PM, John wrote:
My resolve.conf points to google (8.8.8.8, 8.8.4.4 + their ipv6 equivalents). I have heard rumours of problems with Google DNS, I am not sure that I believe them but ... Is this their problem or mine (its mine because I have it) and what might be my best solution. TIA -- Sent from my Samsung Galaxy Tab 3
On 9 April, 2015 10:04:41 AM Viktor Dukhovni ietf-dane@dukhovni.org wrote:
On Thu, Apr 09, 2015 at 08:40:27AM -0400, John Allen wrote:
When I try "posttls-finger dane.sys4.de" I get the following. I have emphasized a couple of areas in the following text that cause me some concern.
posttls-finger: Connected to dane.sys4.de[194.126.158.134]:25
No TLSA records were found. Your DNS resolver is not returning the "AD" bit for this domain. Check /etc/resolv.conf.
I get:
$ posttls-finger -c dane.sys4.de posttls-finger: using DANE RR: _25._tcp.dane.sys4.de IN TLSA 3 01 C8:B7:60:93:10:0F:05:3B:95:B5:12:DA:D8:B5:9B:B3:43:02:F7:6B:A8:C0:7E:D8:7F:BF:56:65:BF:05:F1:D1 posttls-finger: dane.sys4.de[194.126.158.134]:25: depth=0 matched end entity certificate sha256 digest C8:B7:60:93:10:0F:05:3B:95:B5:12:DA:D8:B5:9B:B3:43:02:F7:6B:A8:C0:7E:D8:7F:BF:56:65:BF:05:F1:D1 posttls-finger: dane.sys4.de[194.126.158.134]:25: Matched subjectAltName: dane.sys4.de posttls-finger: dane.sys4.de[194.126.158.134]:25: subjectAltName: sys4.de posttls-finger: dane.sys4.de[194.126.158.134]:25 CommonName dane.sys4.de posttls-finger: dane.sys4.de[194.126.158.134]:25: subject_CN=dane.sys4.de, issuer_CN=StartCom Class 2 Primary Intermediate Server CA, fingerprint=41:B5:70:D5:35:68:72:B2:64:4C:5E:DE:74:52:23:E1:3B:3A:03:07, pkey_fingerprint=E5:CD:96:DD:35:8C:91:30:75:5B:D0:66:47:1D:CD:83:39:9A:D5:CC posttls-finger: Verified TLS connection established to dane.sys4.de[194.126.158.134]:25: TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)
With the first line showing working DNSSEC resolution.
posttls-finger: Untrusted TLS connection established to
dane.sys4.de[194.126.158.134]:25: TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)
As a result, authentication fails, since no CAs are trusted by default, and the default security level is opportunistic "dane" not CA-based "secure".
Certificate verification fails and I wind up with an untrusted
connection.
Is this something I did or is there a real problem?
Your server's local DNS resolver is not a DNSSEC validating resolver. Or perhaps is not even local.
To enable outbound DANE, you need an /etc/resolv.conf with 127.0.0.1 as the only nameserver, and DNSSEC validation via the ICANN root enabled in that resolver0.
-- Viktor.