Cached · just now
91/100 SECURITY SCORE

Certificate Information

Subject
CN=proslack.com
Issuer
C=US, O=Let's Encrypt, CN=R12
Valid From
March 03, 2026
Valid Until
June 01, 2026 24 days
Public Key
RSA 4096 bit Strong
Signature Algorithm
SHA256-RSA
SHA-256 Fingerprint
3F:AF:9E:60:BB:39:D6:8C:DB:99:0C:4D:85:EF:89:23:16:C7:28:77:09:F6:8B:00:80:06:5F:32:46:0D:B4:8B
Alternative Names

Security Configuration

TLS Protocols
TLS 1.2 TLS 1.3
Forward Secrecy
Supported (Modern clients use PFS)

HTTP Security Headers

Status
Strict-Transport-Security
Excellent
max-age=31536000; includeSubDomains; preload
Content-Security-Policy
Basic
default-src; script-src; script-src-attr; +8 more Analyze
Content-Security-Policy-Report-Only
Missing
Not configured Analyze
X-Frame-Options
Good
SAMEORIGIN
X-Content-Type-Options
Good
nosniff
Referrer-Policy
Present
same-origin
Permissions-Policy
Present
accelerometer=(), browsing-topics=(), camera=(); +15 more
Recommendations
  • Improve CSP by adding more specific directives and removing 'unsafe-inline'

CAA Records (Certificate Authority Authorization)

CAA Records
Not Configured (Any CA can issue certificates)
CAA Issues
  • No CAA records configured - any CA can issue certificates
Recommendations
  • Implement CAA records to restrict which CAs can issue certificates for your domain
  • This adds an extra layer of security against unauthorized certificate issuance
  • Example: Add CAA record 'example.com. CAA 0 issue "letsencrypt.org"'
  • Consider adding 'iodef' record to receive security incident reports

Subject Alternative Names

1 domain