dropbox.com
HTTPS & TLS
100/100A+- HTTPS certificateDigiCert Inc10/10
HTTPS with a valid certificate from DigiCert Inc.
- Certificate expiry1864/4
The certificate is valid for another 186 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 strengthECDSA P-2562/2
A strong key: ECDSA P-256.
- HTTP → HTTPS3013/3
http:// redirects straight to https://.
- HSTS1 year4/4
HSTS tells browsers to use HTTPS only, for 1 year.
- HTTP/2 and HTTP/3HTTP/32/2
HTTP/2 and HTTP/3.
DNS
79/100B- DNSSEC0/3
Not signed with DNSSEC: a forged DNS answer for the domain cannot be told from the real one.
- 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.
- CAA recordsamazonaws.com, digicert.com, letsencrypt.org2/2
CAA records name the authorities allowed to issue its certificates.
- 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~all4/5
SPF lists the servers allowed to send its mail and marks the rest as suspicious (~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
78/100B- Permissions-Policy0/0.5
No Permissions-Policy: embedded content may ask for camera, microphone or location.
- RPKIunknown1/4
The route to the website is not covered by RPKI, so a hijack of it cannot be told apart.
- Content Security Policy3/3
A Content Security Policy limits which scripts the pages run.
- X-Content-Type-Options2/2
X-Content-Type-Options: nosniff stops browsers guessing file types.
- Framing2/2
Other sites cannot frame its pages (clickjacking protection).
- Referrer-Policystrict-origin-when-cross-origin0.5/0.5
Referrer-Policy limits what other sites learn about where visitors came from.
- IPv64/4
www.dropbox.com is reachable over IPv6 as well as IPv4.
Dependencies
80/100B- 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 everything5/5
The website, DNS and email do not all hang on one company.
Who runs it
- Website
- DROPBOX
- Proofpoint
Routes
- 162.125.71.0/24AS19679RPKI unknown
- 2620:100:6026::/48AS19679RPKI unknown
Name servers
- ns-1162.awsdns-17.orgAmazon Route 53AS16509
- ns-1949.awsdns-51.co.ukAmazon Route 53AS16509
- ns-315.awsdns-39.comAmazon Route 53AS16509
- ns-564.awsdns-06.netAmazon Route 53AS16509
README badge
Show the grade in your README or docs; it updates when the domain is graded again.
[](https://skycisa.com/grade/dropbox.com)Compare with…
What is graded
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.
At least two name servers that all answer and agree, DNSSEC, CAA records, and a registration that is not about to expire.
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.
Content Security Policy, nosniff, framing protection, Referrer- and Permissions-Policy, IPv6, and an RPKI-valid route (invalid means at most C).
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