Infrastructure report cardTop 50K site

slack.com

81 out of 10016 passed5 to improve

Checked 2 days ago· Grading…

HTTPS & TLSA⁺

Certificate, protocol, redirect, HSTS100

DNSA⁺

Name servers, DNSSEC, CAA, registration100

EmailA

SPF, DMARC, MTA-STS, DKIM85

Web & networkD

Security headers, IPv6, RPKI50

DependenciesD

How much hangs on one company60

HTTPS & TLS

100/100A⁺

HTTPS certificateLet's Encrypt10/10
HTTPS with a valid certificate from Let's Encrypt.
Certificate expiry834/4
The certificate is valid for another 83 days.
TLS versionTLS 1.34/4
Negotiates TLS 1.3, the current protocol: faster handshakes, forward secrecy always.
Old protocols3/3
Refuses the retired TLS 1.0 and 1.1.
Key strengthRSA 20482/2
A strong key: RSA 2048.
HTTP → HTTPS3013/3
http:// redirects straight to https://.
HSTS1 year · preload4/4
HSTS tells browsers to use HTTPS only, for 1 year.
HTTP/2 and HTTP/3HTTP/32/2
HTTP/2 and HTTP/3.

DNS

100/100A⁺

Name servers44/4
4 name servers for the domain.
Name servers answer4/45/5
Every name server answers for the domain, with the same version of the zone.
DNSSECECDSAP256SHA2563/3
Signed with DNSSEC: resolvers can tell forged answers from real ones.
CAA recordsdigicert.com, letsencrypt.org2/2
CAA records name the authorities allowed to issue its certificates.

Email

85/100A

MTA-STS0/2
No MTA-STS: mail to the domain can be read in transit by stripping its encryption.
TLS reporting0/0.5
No TLS reporting: failed encrypted deliveries go unnoticed.
SPF-all5/5
SPF lists the servers allowed to send its mail and rejects the rest (-all).
DMARCreject7/7
DMARC tells receivers to reject mail that fakes the domain (p=reject).
DKIMzendesk12/2
A DKIM key is published (selector zendesk1), so its mail can be signed.

Web & network

50/100D

IPv60/4
slack.com has no IPv6 address: IPv6-only networks reach it only through translation.
Security headers
The website answered 429 to the check (bot protection, most likely), so its headers are not graded.
RPKIvalid4/4
The route to the website is RPKI-valid: networks can reject hijacked announcements of it.

Dependencies

60/100D

DNS providersAmazon Route 533/5
All DNS is with one provider (Amazon Route 53): an outage there takes the domain offline, as Dyn's did in 2016.
One company for everythingAmazon Web Services: website, DNS3/5
Amazon Web Services runs both the website and the DNS: one outage there takes both down.

Who runs it

Website: Amazon Web Services
DNS: Amazon Route 53
Email: Google Workspace

Routes

3.64.0.0/12AS16509RPKI valid

Name servers

ns-1493.awsdns-58.orgAmazon Route 53AS16509
ns-166.awsdns-20.comAmazon Route 53AS16509
ns-1901.awsdns-45.co.ukAmazon Route 53AS16509
ns-606.awsdns-11.netAmazon Route 53AS16509

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Full lookup Is it down?

What is graded

HTTPS & TLS · 25%

A valid certificate (an invalid one means F), its expiry against its lifetime, TLS 1.3, no TLS 1.0/1.1 (else at most B), http:// sent straight to https://, HSTS, HTTP/2.

DNS · 20%

At least two name servers that all answer and agree, DNSSEC, CAA records, and a registration that is not about to expire.

Email · 20%

SPF, a DMARC policy that rejects forgeries (none means at most B), MTA-STS and TLS reporting for domains that take mail, DKIM at common selectors.

Web & network · 20%

Content Security Policy, nosniff, framing protection, Referrer- and Permissions-Policy, IPv6, and an RPKI-valid route (invalid means at most C).

Dependencies · 15%

DNS from more than one provider, and the website, DNS and email not all with one company.

A+ 95–100 · A 85–94 · B 75–84 · C 65–74 · D 50–64 · F below 50