SSLSCAN(1) General Commands Manual SSLSCAN(1)

sslscan - Fast SSL/TLS scanner

sslscan [options] [host:port | host]

sslscan queries SSL/TLS services (such as HTTPS) and reports the protocol versions, cipher suites, key exchanges, signature algorithms, and certificates in use. This helps the user understand which parameters are weak from a security standpoint.

Terminal output is thus colour-coded as follows:

Red Background NULL cipher (no encryption)
Red Broken cipher (<= 40 bit), broken protocol (SSLv2 or SSLv3) or broken certificate signing algorithm (MD5)
Yellow Weak cipher (<= 56 bit or RC4) or weak certificate signing algorithm (SHA-1)
Purple Anonymous cipher (ADH or AECDH)

sslscan can also output results into an XML file for easy consumption by external programs.

Show summary of options
A file containing a list of hosts to check. Hosts can be supplied with ports (i.e. host:port). One target per line
Use a different hostname for SNI

Force IPv4 DNS resolution. Default is to try IPv4, and if that fails then fall back to IPv6.

Force IPv6 DNS resolution. Default is to try IPv4, and if that fails then fall back to IPv6.
Display certificate information.
Don't flag certificates signed with weak algorithms (MD5 and SHA-1) or short (<2048 bit) RSA keys
Show a list of CAs that the server allows for client authentication. Will be blank for IIS/Schannel servers.
Show a complete list of ciphers supported by sslscan
Print the hexadecimal cipher IDs
Use IANA/RFC cipher names rather than OpenSSL ones
Show the time taken for each handshake in milliseconds. Note that only a single request is made with each cipher, and that the size of the ClientHello is not constant, so this should not be used for proper benchmarking or performance testing.

You might want to also use --no-cipher-details to make the output a bit clearer.

Only check if SSLv2 is enabled

Only check if SSLv3 is enabled

Only check TLS 1.0 ciphers

Only check TLS 1.1 ciphers

Only check TLS 1.2 ciphers

Only check TLS 1.3 ciphers

Only check TLS ciphers (versions 1.0, 1.1, 1.2, and 1.3)

Display OCSP status
A file containing the private key or a PKCS#12 file containing a private key/certificate pair (as produced by MSIE and Netscape)
The password for the private key or PKCS#12 file
A file containing PEM/ASN1 formatted client certificates
Do not scan for supported ciphersuites.
Do not check for TLS Fallback Signaling Cipher Suite Value (fallback)
Do not check for secure TLS renegotiation
Do not check for TLS compression (CRIME)
Do not check for OpenSSL Heartbleed (CVE-2014-0160)
Do not enumerate key exchange groups
Enumerate signature algorithms
STARTTLS setup for FTP
STARTTLS setup for IRC
STARTTLS setup for POP3
STARTTLS setup for MySQL
STARTTLS setup for PostgreSQL
Perform a server-to-server XMPP connection. Try this if --starttls-xmpp is failing.

Send RDP preamble before starting scan.

Enables workarounds for SSL bugs

Set socket timeout. Useful for hosts that fail to respond to ciphers they don't understand. Default is 3s.

Set initial connection timeout. Useful for hosts that are slow to respond to the initial connect(). Default is 75s.

Pause between connections. Useful on STARTTLS SMTP services, or anything else that's performing rate limiting. Default is disabled.

Output results to an XML file. - can be used to mean stdout.
Show version of program
Display verbose output

Hide NIST EC curve name and EDH/RSA key length.

Disable coloured output.

Scan a local HTTPS server

sslscan localhost
sslscan [::1]
sslscan [::1]:443

sslscan was originally written by Ian Ventura-Whiting <>.
sslscan was extended by Jacob Appelbaum <>.
sslscan was extended by rbsec <>.
This manual page was originally written by Marvin Stark <>.

March 19, 2020